diff --git a/CHANGELOG.md b/CHANGELOG.md
index df01f87a1..4ccc7e0a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,36 +3,58 @@
 ## Roadmap
 
 BREAKING CHANGES:
-- Upgrade the header to support better proves on validtors, results, evidence, and possibly more
+- Upgrade the header to support better proofs on validtors, results, evidence, and possibly more
 - Better support for injecting randomness
 - Pass evidence/voteInfo through ABCI
 - Upgrade consensus for more real-time use of evidence
 
 FEATURES:
 - Peer reputation management
-- Use the chain as its own CA for nodes and validators     
-- Tooling to run multiple blockchains/apps, possibly in a single process      
-- State syncing (without transaction replay)      
-- Improved support for querying history and state        
+- Use the chain as its own CA for nodes and validators
+- Tooling to run multiple blockchains/apps, possibly in a single process
+- State syncing (without transaction replay)
+- Improved support for querying history and state
 - Add authentication and rate-limitting to the RPC
 
 IMPROVEMENTS:
-- Improve subtleties around mempool caching and logic		
-- Consensus optimizations: 		
+- Improve subtleties around mempool caching and logic
+- Consensus optimizations:
 	- cache block parts for faster agreement after round changes
 	- propagate block parts rarest first
-- Better testing of the consensus state machine (ie. use a DSL)		
+- Better testing of the consensus state machine (ie. use a DSL)
 - Auto compiled serialization/deserialization code instead of go-wire reflection
 
-BUG FIXES:		
-- Graceful handling/recovery for apps that have non-determinism or fail to halt		
+BUG FIXES:
+- Graceful handling/recovery for apps that have non-determinism or fail to halt
 - Graceful handling/recovery for violations of safety, or liveness
 
-## 0.10.4 (Septemeber 5, 2017)
+## 0.11.0 (September 22, 2017)
+
+BREAKING:
+ - state: every validator set change is persisted to disk, which required some changes to the `State` structure.
+ - cmd: if there is no genesis, exit immediately instead of waiting around for one to show.
+ - p2p: new `p2p.Peer` interface used for all reactor methods (instead of `*p2p.Peer` struct).
+ - types: `Signer.Sign` returns an error.
+ - rpc: various changes to match JSONRPC spec (http://www.jsonrpc.org/specification), including breaking ones:
+    - requests that previously returned HTTP code 4XX now return 200 with an error code in the JSONRPC.
+    - `rpctypes.RPCResponse` uses new `RPCError` type instead of `string`.
+ - abci: Info, BeginBlock, InitChain all take structs
+
+FEATURES:
+ - rpc: `/validators?height=X` allows querying of validators at previous heights.
+ - rpc: Leaving the `height` param empty for `/block`, `/validators`, and `/commit` will return the value for the latest height.
+
+IMPROVEMENTS:
+ - docs: Moved all docs from the website and tools repo in, converted to `.rst`, and cleaned up for presentation on `tendermint.readthedocs.io`
+
+BUG FIXES:
+ - fix WAL openning issue on Windows
+
+## 0.10.4 (September 5, 2017)
 
 IMPROVEMENTS:
-- docs: Added Slate docs to each rpc function (see rpc/core) 
-- docs: Ported all website docs to Read The Docs 
+- docs: Added Slate docs to each rpc function (see rpc/core)
+- docs: Ported all website docs to Read The Docs
 - config: expose some p2p params to tweak performance: RecvRate, SendRate, and MaxMsgPacketPayloadSize
 - rpc: Upgrade the websocket client and server, including improved auto reconnect, and proper ping/pong
 
@@ -72,7 +94,7 @@ IMPROVEMENTS:
 
 FEATURES:
 - Use `--trace` to get stack traces for logged errors
-- types: GenesisDoc.ValidatorHash returns the hash of the genesis validator set 
+- types: GenesisDoc.ValidatorHash returns the hash of the genesis validator set
 - types: GenesisDocFromFile parses a GenesiDoc from a JSON file
 
 IMPROVEMENTS:
@@ -96,7 +118,7 @@ Also includes the Grand Repo-Merge of 2017.
 BREAKING CHANGES:
 
 - Config and Flags:
-  - The `config` map is replaced with a [`Config` struct](https://github.com/tendermint/tendermint/blob/master/config/config.go#L11), 
+  - The `config` map is replaced with a [`Config` struct](https://github.com/tendermint/tendermint/blob/master/config/config.go#L11),
 containing substructs: `BaseConfig`, `P2PConfig`, `MempoolConfig`, `ConsensusConfig`, `RPCConfig`
   - This affects the following flags:
     - `--seeds` is now `--p2p.seeds`
@@ -109,16 +131,16 @@ containing substructs: `BaseConfig`, `P2PConfig`, `MempoolConfig`, `ConsensusCon
     ```
     [p2p]
     laddr="tcp://1.2.3.4:46656"
-    
+
     [consensus]
     timeout_propose=1000
     ```
   - Use viper and `DefaultConfig() / TestConfig()` functions to handle defaults, and remove `config/tendermint` and `config/tendermint_test`
-  - Change some function and method signatures to 
+  - Change some function and method signatures to
   - Change some [function and method signatures](https://gist.github.com/ebuchman/640d5fc6c2605f73497992fe107ebe0b) accomodate new config
 
 - Logger
-  - Replace static `log15` logger with a simple interface, and provide a new implementation using `go-kit`. 
+  - Replace static `log15` logger with a simple interface, and provide a new implementation using `go-kit`.
 See our new [logging library](https://github.com/tendermint/tmlibs/log) and [blog post](https://tendermint.com/blog/abstracting-the-logger-interface-in-go) for more details
   - Levels `warn` and `notice` are removed (you may need to change them in your `config.toml`!)
   - Change some [function and method signatures](https://gist.github.com/ebuchman/640d5fc6c2605f73497992fe107ebe0b) to accept a logger
@@ -161,7 +183,7 @@ IMPROVEMENTS:
 - Limit `/blockchain_info` call to return a maximum of 20 blocks
 - Use `.Wrap()` and `.Unwrap()` instead of eg. `PubKeyS` for `go-crypto` types
 - RPC JSON responses use pretty printing (via `json.MarshalIndent`)
-- Color code different instances of the consensus for tests 
+- Color code different instances of the consensus for tests
 - Isolate viper to `cmd/tendermint/commands` and do not read config from file for tests
 
 
@@ -189,7 +211,7 @@ IMPROVEMENTS:
 - WAL uses #ENDHEIGHT instead of #HEIGHT (#HEIGHT will stop working in 0.10.0)
 - Peers included via `--seeds`, under `seeds` in the config, or in `/dial_seeds` are now persistent, and will be reconnected to if the connection breaks
 
-BUG FIXES: 
+BUG FIXES:
 
 - Fix bug in fast-sync where we stop syncing after a peer is removed, even if they're re-added later
 - Fix handshake replay to handle validator set changes and results of DeliverTx when we crash after app.Commit but before state.Save()
@@ -205,7 +227,7 @@ message RequestQuery{
 	bytes data = 1;
 	string path = 2;
 	uint64 height = 3;
-	bool prove = 4; 
+	bool prove = 4;
 }
 
 message ResponseQuery{
@@ -229,7 +251,7 @@ type BlockMeta struct {
 }
 ```
 
-- `ValidatorSet.Proposer` is exposed as a field and persisted with the `State`. Use `GetProposer()` to initialize or update after validator-set changes. 
+- `ValidatorSet.Proposer` is exposed as a field and persisted with the `State`. Use `GetProposer()` to initialize or update after validator-set changes.
 
 - `tendermint gen_validator` command output is now pure JSON
 
@@ -272,7 +294,7 @@ type BlockID struct {
 }
 ```
 
-- `Vote` data type now includes validator address and index: 
+- `Vote` data type now includes validator address and index:
 
 ```
 type Vote struct {
@@ -292,7 +314,7 @@ type Vote struct {
 
 FEATURES:
 
-- New message type on the ConsensusReactor, `Maj23Msg`, for peers to alert others they've seen a Maj23, 
+- New message type on the ConsensusReactor, `Maj23Msg`, for peers to alert others they've seen a Maj23,
 in order to track and handle conflicting votes intelligently to prevent Byzantine faults from causing halts:
 
 ```
@@ -315,7 +337,7 @@ IMPROVEMENTS:
 - Less verbose logging
 - Better test coverage (37% -> 49%)
 - Canonical SignBytes for signable types
-- Write-Ahead Log for Mempool and Consensus via tmlibs/autofile 
+- Write-Ahead Log for Mempool and Consensus via tmlibs/autofile
 - Better in-process testing for the consensus reactor and byzantine faults
 - Better crash/restart testing for individual nodes at preset failure points, and of networks at arbitrary points
 - Better abstraction over timeout mechanics
@@ -395,7 +417,7 @@ FEATURES:
 - TMSP and RPC support TCP and UNIX sockets
 - Addition config options including block size and consensus parameters
 - New WAL mode `cswal_light`; logs only the validator's own votes
-- New RPC endpoints: 
+- New RPC endpoints:
 	- for starting/stopping profilers, and for updating config
 	- `/broadcast_tx_commit`, returns when tx is included in a block, else an error
 	- `/unsafe_flush_mempool`, empties the mempool
@@ -416,14 +438,14 @@ BUG FIXES:
 
 Strict versioning only began with the release of v0.7.0, in late summer 2016.
 The project itself began in early summer 2014 and was workable decentralized cryptocurrency software by the end of that year.
-Through the course of 2015, in collaboration with Eris Industries (now Monax Indsutries), 
+Through the course of 2015, in collaboration with Eris Industries (now Monax Indsutries),
 many additional features were integrated, including an implementation from scratch of the Ethereum Virtual Machine.
 That implementation now forms the heart of [Burrow](https://github.com/hyperledger/burrow).
 In the later half of 2015, the consensus algorithm was upgraded with a more asynchronous design and a more deterministic and robust implementation.
 
-By late 2015, frustration with the difficulty of forking a large monolithic stack to create alternative cryptocurrency designs led to the 
+By late 2015, frustration with the difficulty of forking a large monolithic stack to create alternative cryptocurrency designs led to the
 invention of the Application Blockchain Interface (ABCI), then called the Tendermint Socket Protocol (TMSP).
 The Ethereum Virtual Machine and various other transaction features were removed, and Tendermint was whittled down to a core consensus engine
-driving an application running in another process. 
+driving an application running in another process.
 The ABCI interface and implementation were iterated on and improved over the course of 2016,
 until versioned history kicked in with v0.7.0.
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f5ceee3cf..a996acad5 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,6 +1,6 @@
 # Contributing
 
-Thank you for considering making contributions to Tendermint and related repositories (Basecoin, Merkleeyes, etc.)!
+Thank you for considering making contributions to Tendermint and related repositories! Start by taking a look at the [coding repo](https://github.com/tendermint/coding) for overall information on repository workflow and standards.
 
 Please follow standard github best practices: fork the repo, branch from the tip of develop, make some commits, and submit a pull request to develop. See the [open issues](https://github.com/tendermint/tendermint/issues) for things we need help with!
 
diff --git a/README.md b/README.md
index f6ef76042..420057976 100644
--- a/README.md
+++ b/README.md
@@ -13,22 +13,17 @@ https://camo.githubusercontent.com/915b7be44ada53c290eb157634330494ebe3e30a/6874
 [![](https://tokei.rs/b1/github/tendermint/tendermint?category=lines)](https://github.com/tendermint/tendermint)
 
 
-Branch    | Tests | Coverage | Report Card
-----------|-------|----------|-------------
-develop   | [![CircleCI](https://circleci.com/gh/tendermint/tendermint/tree/develop.svg?style=shield)](https://circleci.com/gh/tendermint/tendermint/tree/develop) | [![codecov](https://codecov.io/gh/tendermint/tendermint/branch/develop/graph/badge.svg)](https://codecov.io/gh/tendermint/tendermint) | [![Go Report Card](https://goreportcard.com/badge/github.com/tendermint/tendermint/tree/develop)](https://goreportcard.com/report/github.com/tendermint/tendermint/tree/develop)
-master    | [![CircleCI](https://circleci.com/gh/tendermint/tendermint/tree/master.svg?style=shield)](https://circleci.com/gh/tendermint/tendermint/tree/master) | [![codecov](https://codecov.io/gh/tendermint/tendermint/branch/master/graph/badge.svg)](https://codecov.io/gh/tendermint/tendermint) | [![Go Report Card](https://goreportcard.com/badge/github.com/tendermint/tendermint/tree/master)](https://goreportcard.com/report/github.com/tendermint/tendermint/tree/master)
+Branch    | Tests | Coverage 
+----------|-------|----------
+master    | [![CircleCI](https://circleci.com/gh/tendermint/tendermint/tree/master.svg?style=shield)](https://circleci.com/gh/tendermint/tendermint/tree/master) | [![codecov](https://codecov.io/gh/tendermint/tendermint/branch/master/graph/badge.svg)](https://codecov.io/gh/tendermint/tendermint)
+develop   | [![CircleCI](https://circleci.com/gh/tendermint/tendermint/tree/develop.svg?style=shield)](https://circleci.com/gh/tendermint/tendermint/tree/develop) | [![codecov](https://codecov.io/gh/tendermint/tendermint/branch/develop/graph/badge.svg)](https://codecov.io/gh/tendermint/tendermint)
 
 _NOTE: This is alpha software. Please contact us if you intend to run it in production._
 
-Tendermint Core is Byzantine Fault Tolerant (BFT) middleware that takes a state transition machine, written in any programming language,
+Tendermint Core is Byzantine Fault Tolerant (BFT) middleware that takes a state transition machine - written in any programming language -
 and securely replicates it on many machines.
 
-For more background, see the [introduction](https://tendermint.com/intro).
-
-To get started developing applications, see the [application developers guide](https://tendermint.com/docs/guides/app-development).
-
-### Code of Conduct
-Please read, understand and adhere to our [code of conduct](CODE_OF_CONDUCT.md).
+For more information, from introduction to install to application development, [Read The Docs](http://tendermint.readthedocs.io/projects/tools/en/master).
 
 ## Install
 
@@ -38,39 +33,72 @@ To install from source, you should be able to:
 
 `go get -u github.com/tendermint/tendermint/cmd/tendermint`
 
-For more details (or if it fails), see the [install guide](https://tendermint.com/docs/guides/install-from-source).
-
-## Contributing
-
-Yay open source! Please see our [contributing guidelines](CONTRIBUTING.md).
+For more details (or if it fails), [read the docs](http://tendermint.readthedocs.io/projects/tools/en/master/install.html).
 
 ## Resources
 
 ### Tendermint Core
 
-- [Introduction](https://tendermint.com/intro)
-- [Docs](https://tendermint.com/docs)
-- [Software using Tendermint](https://tendermint.com/ecosystem)
+All resources involving the use of, building application on, or developing for, tendermint, can be found at [Read The Docs](http://tendermint.readthedocs.io/projects/tools/en/master). Additional information about some - and eventually all - of the sub-projects below, can be found at Read The Docs.
 
 ### Sub-projects
 
 * [ABCI](http://github.com/tendermint/abci), the Application Blockchain Interface
 * [Go-Wire](http://github.com/tendermint/go-wire), a deterministic serialization library
 * [Go-Crypto](http://github.com/tendermint/go-crypto), an elliptic curve cryptography library
-* [TmLibs](http://github.com/tendermint/tmlibs), an assortment of Go libraries
-* [Merkleeyes](http://github.com/tendermint/merkleeyes), a balanced, binary Merkle tree for ABCI apps
+* [TmLibs](http://github.com/tendermint/tmlibs), an assortment of Go libraries used internally
+* [IAVL](http://github.com/tendermint/iavl), Merkleized IAVL+ Tree implementation
 
 ### Tools
-* [Deployment, Benchmarking, and Monitoring](https://github.com/tendermint/tools)
+* [Deployment, Benchmarking, and Monitoring](http://tendermint.readthedocs.io/projects/tools/en/develop/index.html#tendermint-tools)
 
 ### Applications
 
-* [Ethermint](http://github.com/tendermint/ethermint): Ethereum on Tendermint
-* [Basecoin](http://github.com/tendermint/basecoin), a cryptocurrency application framework
+* [Ethermint](http://github.com/tendermint/ethermint); Ethereum on Tendermint
+* [Cosmos SDK](http://github.com/cosmos/cosmos-sdk); a cryptocurrency application framework
 
 ### More
 
+* [Master's Thesis on Tendermint](https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9769)
+* [Original Whitepaper](https://tendermint.com/static/docs/tendermint.pdf)
 * [Tendermint Blog](https://blog.cosmos.network/tendermint/home)
 * [Cosmos Blog](https://blog.cosmos.network)
-* [Original Whitepaper (out-of-date)](http://www.the-blockchain.com/docs/Tendermint%20Consensus%20without%20Mining.pdf)
-* [Master's Thesis on Tendermint](https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9769)
+
+## Contributing
+
+Yay open source! Please see our [contributing guidelines](CONTRIBUTING.md).
+
+## Versioning
+
+### SemVer
+
+Tendermint uses [SemVer](http://semver.org/) to determine when and how the version changes.
+According to SemVer, anything in the public API can change at any time before version 1.0.0
+
+To provide some stability to Tendermint users in these 0.X.X days, the MINOR version is used
+to signal breaking changes across a subset of the total public API. This subset includes all
+interfaces exposed to other processes (cli, rpc, p2p, etc.), as well as parts of the following packages:
+
+- types
+- rpc/client
+- config
+- node
+
+Exported objects in these packages that are not covered by the versioning scheme
+are explicitly marked by `// UNSTABLE` in their go doc comment and may change at any time.
+Functions, types, and values in any other package may also change at any time.
+
+### Upgrades
+
+In an effort to avoid accumulating technical debt prior to 1.0.0,
+we do not guarantee that breaking changes (ie. bumps in the MINOR version)
+will work with existing tendermint blockchains. In these cases you will
+have to start a new blockchain, or write something custom to get the old
+data into the new chain.
+
+However, any bump in the PATCH version should be compatible with existing histories
+(if not please open an [issue](https://github.com/tendermint/tendermint/issues)).
+
+## Code of Conduct
+
+Please read, understand and adhere to our [code of conduct](CODE_OF_CONDUCT.md).
diff --git a/blockchain/pool.go b/blockchain/pool.go
index e1288c9fa..924880c08 100644
--- a/blockchain/pool.go
+++ b/blockchain/pool.go
@@ -352,7 +352,7 @@ func (peer *bpPeer) setLogger(l log.Logger) {
 
 func (peer *bpPeer) resetMonitor() {
 	peer.recvMonitor = flow.New(time.Second, time.Second*40)
-	var initialValue = float64(minRecvRate) * math.E
+	initialValue := float64(minRecvRate) * math.E
 	peer.recvMonitor.SetREMA(initialValue)
 }
 
diff --git a/blockchain/reactor.go b/blockchain/reactor.go
index 813d8f6b7..fb68aadda 100644
--- a/blockchain/reactor.go
+++ b/blockchain/reactor.go
@@ -28,7 +28,6 @@ const (
 	statusUpdateIntervalSeconds = 10
 	// check if we should switch to consensus reactor
 	switchToConsensusIntervalSeconds = 1
-	maxBlockchainResponseSize        = types.MaxBlockSize + 2
 )
 
 type consensusReactor interface {
@@ -111,20 +110,20 @@ func (bcR *BlockchainReactor) GetChannels() []*p2p.ChannelDescriptor {
 }
 
 // AddPeer implements Reactor by sending our state to peer.
-func (bcR *BlockchainReactor) AddPeer(peer *p2p.Peer) {
+func (bcR *BlockchainReactor) AddPeer(peer p2p.Peer) {
 	if !peer.Send(BlockchainChannel, struct{ BlockchainMessage }{&bcStatusResponseMessage{bcR.store.Height()}}) {
 		// doing nothing, will try later in `poolRoutine`
 	}
 }
 
 // RemovePeer implements Reactor by removing peer from the pool.
-func (bcR *BlockchainReactor) RemovePeer(peer *p2p.Peer, reason interface{}) {
-	bcR.pool.RemovePeer(peer.Key)
+func (bcR *BlockchainReactor) RemovePeer(peer p2p.Peer, reason interface{}) {
+	bcR.pool.RemovePeer(peer.Key())
 }
 
 // Receive implements Reactor by handling 4 types of messages (look below).
-func (bcR *BlockchainReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte) {
-	_, msg, err := DecodeMessage(msgBytes)
+func (bcR *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
+	_, msg, err := DecodeMessage(msgBytes, bcR.maxMsgSize())
 	if err != nil {
 		bcR.Logger.Error("Error decoding message", "err", err)
 		return
@@ -148,7 +147,7 @@ func (bcR *BlockchainReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte)
 		}
 	case *bcBlockResponseMessage:
 		// Got a block.
-		bcR.pool.AddBlock(src.Key, msg.Block, len(msgBytes))
+		bcR.pool.AddBlock(src.Key(), msg.Block, len(msgBytes))
 	case *bcStatusRequestMessage:
 		// Send peer our state.
 		queued := src.TrySend(BlockchainChannel, struct{ BlockchainMessage }{&bcStatusResponseMessage{bcR.store.Height()}})
@@ -157,12 +156,18 @@ func (bcR *BlockchainReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte)
 		}
 	case *bcStatusResponseMessage:
 		// Got a peer status. Unverified.
-		bcR.pool.SetPeerHeight(src.Key, msg.Height)
+		bcR.pool.SetPeerHeight(src.Key(), msg.Height)
 	default:
 		bcR.Logger.Error(cmn.Fmt("Unknown message type %v", reflect.TypeOf(msg)))
 	}
 }
 
+// maxMsgSize returns the maximum allowable size of a
+// message on the blockchain reactor.
+func (bcR *BlockchainReactor) maxMsgSize() int {
+	return bcR.state.Params().BlockSizeParams.MaxBytes + 2
+}
+
 // Handle messages from the poolReactor telling the reactor what to do.
 // NOTE: Don't sleep in the FOR_LOOP or otherwise slow it down!
 // (Except for the SYNC_LOOP, which is the primary purpose and must be synchronous.)
@@ -221,7 +226,7 @@ FOR_LOOP:
 					// We need both to sync the first block.
 					break SYNC_LOOP
 				}
-				firstParts := first.MakePartSet(types.DefaultBlockPartSize)
+				firstParts := first.MakePartSet(bcR.state.Params().BlockPartSizeBytes)
 				firstPartsHeader := firstParts.Header()
 				// Finally, verify the first block using the second's commit
 				// NOTE: we can probably make this more efficient, but note that calling
@@ -290,11 +295,11 @@ var _ = wire.RegisterInterface(
 
 // DecodeMessage decodes BlockchainMessage.
 // TODO: ensure that bz is completely read.
-func DecodeMessage(bz []byte) (msgType byte, msg BlockchainMessage, err error) {
+func DecodeMessage(bz []byte, maxSize int) (msgType byte, msg BlockchainMessage, err error) {
 	msgType = bz[0]
 	n := int(0)
 	r := bytes.NewReader(bz)
-	msg = wire.ReadBinary(struct{ BlockchainMessage }{}, r, maxBlockchainResponseSize, &n, &err).(struct{ BlockchainMessage }).BlockchainMessage
+	msg = wire.ReadBinary(struct{ BlockchainMessage }{}, r, maxSize, &n, &err).(struct{ BlockchainMessage }).BlockchainMessage
 	if err != nil && n != len(bz) {
 		err = errors.New("DecodeMessage() had bytes left over")
 	}
diff --git a/cmd/tendermint/commands/gen_validator.go b/cmd/tendermint/commands/gen_validator.go
index 97c583c22..984176d2a 100644
--- a/cmd/tendermint/commands/gen_validator.go
+++ b/cmd/tendermint/commands/gen_validator.go
@@ -9,18 +9,16 @@ import (
 	"github.com/tendermint/tendermint/types"
 )
 
-var genValidatorCmd = &cobra.Command{
+// GenValidatorCmd allows the generation of a keypair for a
+// validator.
+var GenValidatorCmd = &cobra.Command{
 	Use:   "gen_validator",
 	Short: "Generate new validator keypair",
 	Run:   genValidator,
 }
 
-func init() {
-	RootCmd.AddCommand(genValidatorCmd)
-}
-
 func genValidator(cmd *cobra.Command, args []string) {
-	privValidator := types.GenPrivValidator()
+	privValidator := types.GenPrivValidatorFS("")
 	privValidatorJSONBytes, _ := json.MarshalIndent(privValidator, "", "\t")
 	fmt.Printf(`%v
 `, string(privValidatorJSONBytes))
diff --git a/cmd/tendermint/commands/init.go b/cmd/tendermint/commands/init.go
index cd16707cc..cbafac3ef 100644
--- a/cmd/tendermint/commands/init.go
+++ b/cmd/tendermint/commands/init.go
@@ -9,21 +9,17 @@ import (
 	cmn "github.com/tendermint/tmlibs/common"
 )
 
-var initFilesCmd = &cobra.Command{
+// InitFilesCmd initialises a fresh Tendermint Core instance.
+var InitFilesCmd = &cobra.Command{
 	Use:   "init",
 	Short: "Initialize Tendermint",
 	Run:   initFiles,
 }
 
-func init() {
-	RootCmd.AddCommand(initFilesCmd)
-}
-
 func initFiles(cmd *cobra.Command, args []string) {
 	privValFile := config.PrivValidatorFile()
 	if _, err := os.Stat(privValFile); os.IsNotExist(err) {
-		privValidator := types.GenPrivValidator()
-		privValidator.SetFile(privValFile)
+		privValidator := types.GenPrivValidatorFS(privValFile)
 		privValidator.Save()
 
 		genFile := config.GenesisFile()
@@ -33,8 +29,8 @@ func initFiles(cmd *cobra.Command, args []string) {
 				ChainID: cmn.Fmt("test-chain-%v", cmn.RandStr(6)),
 			}
 			genDoc.Validators = []types.GenesisValidator{types.GenesisValidator{
-				PubKey: privValidator.PubKey,
-				Amount: 10,
+				PubKey: privValidator.GetPubKey(),
+				Power:  10,
 			}}
 
 			genDoc.SaveAs(genFile)
diff --git a/cmd/tendermint/commands/probe_upnp.go b/cmd/tendermint/commands/probe_upnp.go
index e23e48973..643b7713f 100644
--- a/cmd/tendermint/commands/probe_upnp.go
+++ b/cmd/tendermint/commands/probe_upnp.go
@@ -9,16 +9,13 @@ import (
 	"github.com/tendermint/tendermint/p2p/upnp"
 )
 
-var probeUpnpCmd = &cobra.Command{
+// ProbeUpnpCmd adds capabilities to test the UPnP functionality.
+var ProbeUpnpCmd = &cobra.Command{
 	Use:   "probe_upnp",
 	Short: "Test UPnP functionality",
 	RunE:  probeUpnp,
 }
 
-func init() {
-	RootCmd.AddCommand(probeUpnpCmd)
-}
-
 func probeUpnp(cmd *cobra.Command, args []string) error {
 	capabilities, err := upnp.Probe(logger)
 	if err != nil {
diff --git a/cmd/tendermint/commands/replay.go b/cmd/tendermint/commands/replay.go
index 0c88b2443..303ccba6b 100644
--- a/cmd/tendermint/commands/replay.go
+++ b/cmd/tendermint/commands/replay.go
@@ -6,7 +6,8 @@ import (
 	"github.com/tendermint/tendermint/consensus"
 )
 
-var replayCmd = &cobra.Command{
+// ReplayCmd allows replaying of messages from the WAL.
+var ReplayCmd = &cobra.Command{
 	Use:   "replay",
 	Short: "Replay messages from WAL",
 	Run: func(cmd *cobra.Command, args []string) {
@@ -14,15 +15,12 @@ var replayCmd = &cobra.Command{
 	},
 }
 
-var replayConsoleCmd = &cobra.Command{
+// ReplayConsoleCmd allows replaying of messages from the WAL in a
+// console.
+var ReplayConsoleCmd = &cobra.Command{
 	Use:   "replay_console",
 	Short: "Replay messages from WAL in a console",
 	Run: func(cmd *cobra.Command, args []string) {
 		consensus.RunReplayFile(config.BaseConfig, config.Consensus, true)
 	},
 }
-
-func init() {
-	RootCmd.AddCommand(replayCmd)
-	RootCmd.AddCommand(replayConsoleCmd)
-}
diff --git a/cmd/tendermint/commands/reset_priv_validator.go b/cmd/tendermint/commands/reset_priv_validator.go
index fa12be4ea..b9c08715f 100644
--- a/cmd/tendermint/commands/reset_priv_validator.go
+++ b/cmd/tendermint/commands/reset_priv_validator.go
@@ -9,21 +9,27 @@ import (
 	"github.com/tendermint/tmlibs/log"
 )
 
-var resetAllCmd = &cobra.Command{
+// ResetAllCmd removes the database of this Tendermint core
+// instance.
+var ResetAllCmd = &cobra.Command{
 	Use:   "unsafe_reset_all",
 	Short: "(unsafe) Remove all the data and WAL, reset this node's validator",
 	Run:   resetAll,
 }
 
-var resetPrivValidatorCmd = &cobra.Command{
+// ResetPrivValidatorCmd resets the private validator files.
+var ResetPrivValidatorCmd = &cobra.Command{
 	Use:   "unsafe_reset_priv_validator",
 	Short: "(unsafe) Reset this node's validator",
 	Run:   resetPrivValidator,
 }
 
-func init() {
-	RootCmd.AddCommand(resetAllCmd)
-	RootCmd.AddCommand(resetPrivValidatorCmd)
+// ResetAll removes the privValidator files.
+// Exported so other CLI tools can use  it
+func ResetAll(dbDir, privValFile string, logger log.Logger) {
+	resetPrivValidatorFS(privValFile, logger)
+	os.RemoveAll(dbDir)
+	logger.Info("Removed all data", "dir", dbDir)
 }
 
 // XXX: this is totally unsafe.
@@ -35,26 +41,17 @@ func resetAll(cmd *cobra.Command, args []string) {
 // XXX: this is totally unsafe.
 // it's only suitable for testnets.
 func resetPrivValidator(cmd *cobra.Command, args []string) {
-	resetPrivValidatorLocal(config.PrivValidatorFile(), logger)
-}
-
-// Exported so other CLI tools can use  it
-func ResetAll(dbDir, privValFile string, logger log.Logger) {
-	resetPrivValidatorLocal(privValFile, logger)
-	os.RemoveAll(dbDir)
-	logger.Info("Removed all data", "dir", dbDir)
+	resetPrivValidatorFS(config.PrivValidatorFile(), logger)
 }
 
-func resetPrivValidatorLocal(privValFile string, logger log.Logger) {
+func resetPrivValidatorFS(privValFile string, logger log.Logger) {
 	// Get PrivValidator
-	var privValidator *types.PrivValidator
 	if _, err := os.Stat(privValFile); err == nil {
-		privValidator = types.LoadPrivValidator(privValFile)
+		privValidator := types.LoadPrivValidatorFS(privValFile)
 		privValidator.Reset()
 		logger.Info("Reset PrivValidator", "file", privValFile)
 	} else {
-		privValidator = types.GenPrivValidator()
-		privValidator.SetFile(privValFile)
+		privValidator := types.GenPrivValidatorFS(privValFile)
 		privValidator.Save()
 		logger.Info("Generated PrivValidator", "file", privValFile)
 	}
diff --git a/cmd/tendermint/commands/root.go b/cmd/tendermint/commands/root.go
index 6cef5daa9..a54b50069 100644
--- a/cmd/tendermint/commands/root.go
+++ b/cmd/tendermint/commands/root.go
@@ -34,11 +34,12 @@ func ParseConfig() (*cfg.Config, error) {
 	return conf, err
 }
 
+// RootCmd is the root command for Tendermint core.
 var RootCmd = &cobra.Command{
 	Use:   "tendermint",
 	Short: "Tendermint Core (BFT Consensus) in Go",
 	PersistentPreRunE: func(cmd *cobra.Command, args []string) (err error) {
-		if cmd.Name() == versionCmd.Name() {
+		if cmd.Name() == VersionCmd.Name() {
 			return nil
 		}
 		config, err = ParseConfig()
diff --git a/cmd/tendermint/commands/run_node.go b/cmd/tendermint/commands/run_node.go
index e92911da2..f0a1eede2 100644
--- a/cmd/tendermint/commands/run_node.go
+++ b/cmd/tendermint/commands/run_node.go
@@ -2,26 +2,12 @@ package commands
 
 import (
 	"fmt"
-	"time"
 
 	"github.com/spf13/cobra"
 
-	"github.com/tendermint/tendermint/node"
-	"github.com/tendermint/tendermint/types"
-	cmn "github.com/tendermint/tmlibs/common"
+	nm "github.com/tendermint/tendermint/node"
 )
 
-var runNodeCmd = &cobra.Command{
-	Use:   "node",
-	Short: "Run the tendermint node",
-	RunE:  runNode,
-}
-
-func init() {
-	AddNodeFlags(runNodeCmd)
-	RootCmd.AddCommand(runNodeCmd)
-}
-
 // AddNodeFlags exposes some common configuration options on the command-line
 // These are exposed for convenience of commands embedding a tendermint node
 func AddNodeFlags(cmd *cobra.Command) {
@@ -50,40 +36,32 @@ func AddNodeFlags(cmd *cobra.Command) {
 	cmd.Flags().Bool("consensus.create_empty_blocks", config.Consensus.CreateEmptyBlocks, "Set this to false to only produce blocks when there are txs or when the AppHash changes")
 }
 
-// Users wishing to:
-//	* Use an external signer for their validators
-//	* Supply an in-proc abci app
-// should import github.com/tendermint/tendermint/node and implement
-// their own run_node to call node.NewNode (instead of node.NewNodeDefault)
-// with their custom priv validator and/or custom proxy.ClientCreator
-func runNode(cmd *cobra.Command, args []string) error {
-
-	// Wait until the genesis doc becomes available
-	// This is for Mintnet compatibility.
-	// TODO: If Mintnet gets deprecated or genesis_file is
-	// always available, remove.
-	genDocFile := config.GenesisFile()
-	for !cmn.FileExists(genDocFile) {
-		logger.Info(cmn.Fmt("Waiting for genesis file %v...", genDocFile))
-		time.Sleep(time.Second)
+// NewRunNodeCmd returns the command that allows the CLI to start a
+// node. It can be used with a custom PrivValidator and in-process ABCI application.
+func NewRunNodeCmd(nodeProvider nm.NodeProvider) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "node",
+		Short: "Run the tendermint node",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			// Create & start node
+			n, err := nodeProvider(config, logger)
+			if err != nil {
+				return fmt.Errorf("Failed to create node: %v", err)
+			}
+
+			if _, err := n.Start(); err != nil {
+				return fmt.Errorf("Failed to start node: %v", err)
+			} else {
+				logger.Info("Started node", "nodeInfo", n.Switch().NodeInfo())
+			}
+
+			// Trap signal, run forever.
+			n.RunForever()
+
+			return nil
+		},
 	}
 
-	genDoc, err := types.GenesisDocFromFile(genDocFile)
-	if err != nil {
-		return err
-	}
-	config.ChainID = genDoc.ChainID
-
-	// Create & start node
-	n := node.NewNodeDefault(config, logger.With("module", "node"))
-	if _, err := n.Start(); err != nil {
-		return fmt.Errorf("Failed to start node: %v", err)
-	} else {
-		logger.Info("Started node", "nodeInfo", n.Switch().NodeInfo())
-	}
-
-	// Trap signal, run forever.
-	n.RunForever()
-
-	return nil
+	AddNodeFlags(cmd)
+	return cmd
 }
diff --git a/cmd/tendermint/commands/show_validator.go b/cmd/tendermint/commands/show_validator.go
index 53a687c6d..458f11c2d 100644
--- a/cmd/tendermint/commands/show_validator.go
+++ b/cmd/tendermint/commands/show_validator.go
@@ -9,18 +9,15 @@ import (
 	"github.com/tendermint/tendermint/types"
 )
 
-var showValidatorCmd = &cobra.Command{
+// ShowValidatorCmd adds capabilities for showing the validator info.
+var ShowValidatorCmd = &cobra.Command{
 	Use:   "show_validator",
 	Short: "Show this node's validator info",
 	Run:   showValidator,
 }
 
-func init() {
-	RootCmd.AddCommand(showValidatorCmd)
-}
-
 func showValidator(cmd *cobra.Command, args []string) {
-	privValidator := types.LoadOrGenPrivValidator(config.PrivValidatorFile(), logger)
+	privValidator := types.LoadOrGenPrivValidatorFS(config.PrivValidatorFile())
 	pubKeyJSONBytes, _ := data.ToJSON(privValidator.PubKey)
 	fmt.Println(string(pubKeyJSONBytes))
 }
diff --git a/cmd/tendermint/commands/testnet.go b/cmd/tendermint/commands/testnet.go
index 58767eb05..ac6f337a9 100644
--- a/cmd/tendermint/commands/testnet.go
+++ b/cmd/tendermint/commands/testnet.go
@@ -7,16 +7,10 @@ import (
 
 	"github.com/spf13/cobra"
 
-	cmn "github.com/tendermint/tmlibs/common"
 	"github.com/tendermint/tendermint/types"
+	cmn "github.com/tendermint/tmlibs/common"
 )
 
-var testnetFilesCmd = &cobra.Command{
-	Use:   "testnet",
-	Short: "Initialize files for a Tendermint testnet",
-	Run:   testnetFiles,
-}
-
 //flags
 var (
 	nValidators int
@@ -24,12 +18,18 @@ var (
 )
 
 func init() {
-	testnetFilesCmd.Flags().IntVar(&nValidators, "n", 4,
+	TestnetFilesCmd.Flags().IntVar(&nValidators, "n", 4,
 		"Number of validators to initialize the testnet with")
-	testnetFilesCmd.Flags().StringVar(&dataDir, "dir", "mytestnet",
+	TestnetFilesCmd.Flags().StringVar(&dataDir, "dir", "mytestnet",
 		"Directory to store initialization data for the testnet")
+}
 
-	RootCmd.AddCommand(testnetFilesCmd)
+// TestnetFilesCmd allows initialisation of files for a
+// Tendermint testnet.
+var TestnetFilesCmd = &cobra.Command{
+	Use:   "testnet",
+	Short: "Initialize files for a Tendermint testnet",
+	Run:   testnetFiles,
 }
 
 func testnetFiles(cmd *cobra.Command, args []string) {
@@ -45,10 +45,10 @@ func testnetFiles(cmd *cobra.Command, args []string) {
 		}
 		// Read priv_validator.json to populate vals
 		privValFile := path.Join(dataDir, mach, "priv_validator.json")
-		privVal := types.LoadPrivValidator(privValFile)
+		privVal := types.LoadPrivValidatorFS(privValFile)
 		genVals[i] = types.GenesisValidator{
-			PubKey: privVal.PubKey,
-			Amount: 1,
+			PubKey: privVal.GetPubKey(),
+			Power:  1,
 			Name:   mach,
 		}
 	}
@@ -87,7 +87,6 @@ func ensurePrivValidator(file string) {
 	if cmn.FileExists(file) {
 		return
 	}
-	privValidator := types.GenPrivValidator()
-	privValidator.SetFile(file)
+	privValidator := types.GenPrivValidatorFS(file)
 	privValidator.Save()
 }
diff --git a/cmd/tendermint/commands/version.go b/cmd/tendermint/commands/version.go
index 5c92160ea..f9f545e59 100644
--- a/cmd/tendermint/commands/version.go
+++ b/cmd/tendermint/commands/version.go
@@ -8,14 +8,11 @@ import (
 	"github.com/tendermint/tendermint/version"
 )
 
-var versionCmd = &cobra.Command{
+// VersionCmd ...
+var VersionCmd = &cobra.Command{
 	Use:   "version",
 	Short: "Show version info",
 	Run: func(cmd *cobra.Command, args []string) {
 		fmt.Println(version.Version)
 	},
 }
-
-func init() {
-	RootCmd.AddCommand(versionCmd)
-}
diff --git a/cmd/tendermint/main.go b/cmd/tendermint/main.go
index 5493e4f2f..86ca1531d 100644
--- a/cmd/tendermint/main.go
+++ b/cmd/tendermint/main.go
@@ -3,11 +3,39 @@ package main
 import (
 	"os"
 
-	"github.com/tendermint/tendermint/cmd/tendermint/commands"
 	"github.com/tendermint/tmlibs/cli"
+
+	cmd "github.com/tendermint/tendermint/cmd/tendermint/commands"
+	nm "github.com/tendermint/tendermint/node"
 )
 
 func main() {
-	cmd := cli.PrepareBaseCmd(commands.RootCmd, "TM", os.ExpandEnv("$HOME/.tendermint"))
+	rootCmd := cmd.RootCmd
+	rootCmd.AddCommand(
+		cmd.GenValidatorCmd,
+		cmd.InitFilesCmd,
+		cmd.ProbeUpnpCmd,
+		cmd.ReplayCmd,
+		cmd.ReplayConsoleCmd,
+		cmd.ResetAllCmd,
+		cmd.ResetPrivValidatorCmd,
+		cmd.ShowValidatorCmd,
+		cmd.TestnetFilesCmd,
+		cmd.VersionCmd)
+
+	// NOTE:
+	// Users wishing to:
+	//	* Use an external signer for their validators
+	//	* Supply an in-proc abci app
+	//	* Supply a genesis doc file from another source
+	//	* Provide their own DB implementation
+	// can copy this file and use something other than the
+	// DefaultNewNode function
+	nodeFunc := nm.DefaultNewNode
+
+	// Create & start node
+	rootCmd.AddCommand(cmd.NewRunNodeCmd(nodeFunc))
+
+	cmd := cli.PrepareBaseCmd(rootCmd, "TM", os.ExpandEnv("$HOME/.tendermint"))
 	cmd.Execute()
 }
diff --git a/config/config.go b/config/config.go
index ec1f85edb..23da4f405 100644
--- a/config/config.go
+++ b/config/config.go
@@ -4,8 +4,6 @@ import (
 	"fmt"
 	"path/filepath"
 	"time"
-
-	"github.com/tendermint/tendermint/types" // TODO: remove
 )
 
 // Config defines the top level configuration for a Tendermint node
@@ -320,10 +318,6 @@ type ConsensusConfig struct {
 	CreateEmptyBlocks         bool `mapstructure:"create_empty_blocks"`
 	CreateEmptyBlocksInterval int  `mapstructure:"create_empty_blocks_interval"`
 
-	// TODO: This probably shouldn't be exposed but it makes it
-	// easy to write tests for the wal/replay
-	BlockPartSize int `mapstructure:"block_part_size"`
-
 	// Reactor sleep duration parameters are in ms
 	PeerGossipSleepDuration     int `mapstructure:"peer_gossip_sleep_duration"`
 	PeerQueryMaj23SleepDuration int `mapstructure:"peer_query_maj23_sleep_duration"`
@@ -386,7 +380,6 @@ func DefaultConsensusConfig() *ConsensusConfig {
 		MaxBlockSizeBytes:           1, // TODO
 		CreateEmptyBlocks:           true,
 		CreateEmptyBlocksInterval:   0,
-		BlockPartSize:               types.DefaultBlockPartSize, // TODO: we shouldnt be importing types
 		PeerGossipSleepDuration:     100,
 		PeerQueryMaj23SleepDuration: 2000,
 	}
diff --git a/config/toml.go b/config/toml.go
index 999a05946..5dcbe5332 100644
--- a/config/toml.go
+++ b/config/toml.go
@@ -119,7 +119,7 @@ var testGenesis = `{
         "type": "ed25519",
         "data":"3B3069C422E19688B45CBFAE7BB009FC0FA1B1EA86593519318B7214853803C8"
       },
-      "amount": 10,
+      "power": 10,
       "name": ""
     }
   ],
diff --git a/consensus/byzantine_test.go b/consensus/byzantine_test.go
index 94a03c7aa..0f2d7b040 100644
--- a/consensus/byzantine_test.go
+++ b/consensus/byzantine_test.go
@@ -5,6 +5,8 @@ import (
 	"testing"
 	"time"
 
+	crypto "github.com/tendermint/go-crypto"
+	data "github.com/tendermint/go-wire/data"
 	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/types"
 	. "github.com/tendermint/tmlibs/common"
@@ -53,7 +55,7 @@ func TestByzantine(t *testing.T) {
 	eventLogger := logger.With("module", "events")
 	for i := 0; i < N; i++ {
 		if i == 0 {
-			css[i].privValidator = NewByzantinePrivValidator(css[i].privValidator.(*types.PrivValidator))
+			css[i].privValidator = NewByzantinePrivValidator(css[i].privValidator)
 			// make byzantine
 			css[i].decideProposal = func(j int) func(int, int) {
 				return func(height, round int) {
@@ -188,7 +190,7 @@ func byzantineDecideProposalFunc(t *testing.T, height, round int, cs *ConsensusS
 	}
 }
 
-func sendProposalAndParts(height, round int, cs *ConsensusState, peer *p2p.Peer, proposal *types.Proposal, blockHash []byte, parts *types.PartSet) {
+func sendProposalAndParts(height, round int, cs *ConsensusState, peer p2p.Peer, proposal *types.Proposal, blockHash []byte, parts *types.PartSet) {
 	// proposal
 	msg := &ProposalMessage{Proposal: proposal}
 	peer.Send(DataChannel, struct{ ConsensusMessage }{msg})
@@ -231,14 +233,14 @@ func NewByzantineReactor(conR *ConsensusReactor) *ByzantineReactor {
 
 func (br *ByzantineReactor) SetSwitch(s *p2p.Switch)               { br.reactor.SetSwitch(s) }
 func (br *ByzantineReactor) GetChannels() []*p2p.ChannelDescriptor { return br.reactor.GetChannels() }
-func (br *ByzantineReactor) AddPeer(peer *p2p.Peer) {
+func (br *ByzantineReactor) AddPeer(peer p2p.Peer) {
 	if !br.reactor.IsRunning() {
 		return
 	}
 
 	// Create peerState for peer
-	peerState := NewPeerState(peer)
-	peer.Data.Set(types.PeerStateKey, peerState)
+	peerState := NewPeerState(peer).SetLogger(br.reactor.Logger)
+	peer.Set(types.PeerStateKey, peerState)
 
 	// Send our state to peer.
 	// If we're fast_syncing, broadcast a RoundStepMessage later upon SwitchToConsensus().
@@ -246,10 +248,10 @@ func (br *ByzantineReactor) AddPeer(peer *p2p.Peer) {
 		br.reactor.sendNewRoundStepMessages(peer)
 	}
 }
-func (br *ByzantineReactor) RemovePeer(peer *p2p.Peer, reason interface{}) {
+func (br *ByzantineReactor) RemovePeer(peer p2p.Peer, reason interface{}) {
 	br.reactor.RemovePeer(peer, reason)
 }
-func (br *ByzantineReactor) Receive(chID byte, peer *p2p.Peer, msgBytes []byte) {
+func (br *ByzantineReactor) Receive(chID byte, peer p2p.Peer, msgBytes []byte) {
 	br.reactor.Receive(chID, peer, msgBytes)
 }
 
@@ -257,51 +259,42 @@ func (br *ByzantineReactor) Receive(chID byte, peer *p2p.Peer, msgBytes []byte)
 // byzantine privValidator
 
 type ByzantinePrivValidator struct {
-	Address      []byte `json:"address"`
-	types.Signer `json:"-"`
+	types.Signer
 
-	mtx sync.Mutex
+	pv types.PrivValidator
 }
 
 // Return a priv validator that will sign anything
-func NewByzantinePrivValidator(pv *types.PrivValidator) *ByzantinePrivValidator {
+func NewByzantinePrivValidator(pv types.PrivValidator) *ByzantinePrivValidator {
 	return &ByzantinePrivValidator{
-		Address: pv.Address,
-		Signer:  pv.Signer,
+		Signer: pv.(*types.PrivValidatorFS).Signer,
+		pv:     pv,
 	}
 }
 
-func (privVal *ByzantinePrivValidator) GetAddress() []byte {
-	return privVal.Address
+func (privVal *ByzantinePrivValidator) GetAddress() data.Bytes {
+	return privVal.pv.GetAddress()
 }
 
-func (privVal *ByzantinePrivValidator) SignVote(chainID string, vote *types.Vote) error {
-	privVal.mtx.Lock()
-	defer privVal.mtx.Unlock()
-
-	// Sign
-	vote.Signature = privVal.Sign(types.SignBytes(chainID, vote))
-	return nil
+func (privVal *ByzantinePrivValidator) GetPubKey() crypto.PubKey {
+	return privVal.pv.GetPubKey()
 }
 
-func (privVal *ByzantinePrivValidator) SignProposal(chainID string, proposal *types.Proposal) error {
-	privVal.mtx.Lock()
-	defer privVal.mtx.Unlock()
+func (privVal *ByzantinePrivValidator) SignVote(chainID string, vote *types.Vote) (err error) {
+	vote.Signature, err = privVal.Sign(types.SignBytes(chainID, vote))
+	return err
+}
 
-	// Sign
-	proposal.Signature = privVal.Sign(types.SignBytes(chainID, proposal))
+func (privVal *ByzantinePrivValidator) SignProposal(chainID string, proposal *types.Proposal) (err error) {
+	proposal.Signature, err = privVal.Sign(types.SignBytes(chainID, proposal))
 	return nil
 }
 
-func (privVal *ByzantinePrivValidator) SignHeartbeat(chainID string, heartbeat *types.Heartbeat) error {
-	privVal.mtx.Lock()
-	defer privVal.mtx.Unlock()
-
-	// Sign
-	heartbeat.Signature = privVal.Sign(types.SignBytes(chainID, heartbeat))
+func (privVal *ByzantinePrivValidator) SignHeartbeat(chainID string, heartbeat *types.Heartbeat) (err error) {
+	heartbeat.Signature, err = privVal.Sign(types.SignBytes(chainID, heartbeat))
 	return nil
 }
 
 func (privVal *ByzantinePrivValidator) String() string {
-	return Fmt("PrivValidator{%X}", privVal.Address)
+	return Fmt("PrivValidator{%X}", privVal.GetAddress())
 }
diff --git a/consensus/common_test.go b/consensus/common_test.go
index c59a6d969..b16afc3d0 100644
--- a/consensus/common_test.go
+++ b/consensus/common_test.go
@@ -50,12 +50,12 @@ type validatorStub struct {
 	Index  int // Validator index. NOTE: we don't assume validator set changes.
 	Height int
 	Round  int
-	*types.PrivValidator
+	types.PrivValidator
 }
 
 var testMinPower = 10
 
-func NewValidatorStub(privValidator *types.PrivValidator, valIndex int) *validatorStub {
+func NewValidatorStub(privValidator types.PrivValidator, valIndex int) *validatorStub {
 	return &validatorStub{
 		Index:         valIndex,
 		PrivValidator: privValidator,
@@ -65,7 +65,7 @@ func NewValidatorStub(privValidator *types.PrivValidator, valIndex int) *validat
 func (vs *validatorStub) signVote(voteType byte, hash []byte, header types.PartSetHeader) (*types.Vote, error) {
 	vote := &types.Vote{
 		ValidatorIndex:   vs.Index,
-		ValidatorAddress: vs.PrivValidator.Address,
+		ValidatorAddress: vs.PrivValidator.GetAddress(),
 		Height:           vs.Height,
 		Round:            vs.Round,
 		Type:             voteType,
@@ -142,7 +142,7 @@ func signAddVotes(to *ConsensusState, voteType byte, hash []byte, header types.P
 func validatePrevote(t *testing.T, cs *ConsensusState, round int, privVal *validatorStub, blockHash []byte) {
 	prevotes := cs.Votes.Prevotes(round)
 	var vote *types.Vote
-	if vote = prevotes.GetByAddress(privVal.Address); vote == nil {
+	if vote = prevotes.GetByAddress(privVal.GetAddress()); vote == nil {
 		panic("Failed to find prevote from validator")
 	}
 	if blockHash == nil {
@@ -159,7 +159,7 @@ func validatePrevote(t *testing.T, cs *ConsensusState, round int, privVal *valid
 func validateLastPrecommit(t *testing.T, cs *ConsensusState, privVal *validatorStub, blockHash []byte) {
 	votes := cs.LastCommit
 	var vote *types.Vote
-	if vote = votes.GetByAddress(privVal.Address); vote == nil {
+	if vote = votes.GetByAddress(privVal.GetAddress()); vote == nil {
 		panic("Failed to find precommit from validator")
 	}
 	if !bytes.Equal(vote.BlockID.Hash, blockHash) {
@@ -170,7 +170,7 @@ func validateLastPrecommit(t *testing.T, cs *ConsensusState, privVal *validatorS
 func validatePrecommit(t *testing.T, cs *ConsensusState, thisRound, lockRound int, privVal *validatorStub, votedBlockHash, lockedBlockHash []byte) {
 	precommits := cs.Votes.Precommits(thisRound)
 	var vote *types.Vote
-	if vote = precommits.GetByAddress(privVal.Address); vote == nil {
+	if vote = precommits.GetByAddress(privVal.GetAddress()); vote == nil {
 		panic("Failed to find precommit from validator")
 	}
 
@@ -225,11 +225,11 @@ func subscribeToVoter(cs *ConsensusState, addr []byte) chan interface{} {
 //-------------------------------------------------------------------------------
 // consensus states
 
-func newConsensusState(state *sm.State, pv *types.PrivValidator, app abci.Application) *ConsensusState {
+func newConsensusState(state *sm.State, pv types.PrivValidator, app abci.Application) *ConsensusState {
 	return newConsensusStateWithConfig(config, state, pv, app)
 }
 
-func newConsensusStateWithConfig(thisConfig *cfg.Config, state *sm.State, pv *types.PrivValidator, app abci.Application) *ConsensusState {
+func newConsensusStateWithConfig(thisConfig *cfg.Config, state *sm.State, pv types.PrivValidator, app abci.Application) *ConsensusState {
 	// Get BlockStore
 	blockDB := dbm.NewMemDB()
 	blockStore := bc.NewBlockStore(blockDB)
@@ -258,17 +258,17 @@ func newConsensusStateWithConfig(thisConfig *cfg.Config, state *sm.State, pv *ty
 	return cs
 }
 
-func loadPrivValidator(config *cfg.Config) *types.PrivValidator {
+func loadPrivValidator(config *cfg.Config) *types.PrivValidatorFS {
 	privValidatorFile := config.PrivValidatorFile()
 	ensureDir(path.Dir(privValidatorFile), 0700)
-	privValidator := types.LoadOrGenPrivValidator(privValidatorFile, log.TestingLogger())
+	privValidator := types.LoadOrGenPrivValidatorFS(privValidatorFile)
 	privValidator.Reset()
 	return privValidator
 }
 
 func fixedConsensusStateDummy() *ConsensusState {
 	stateDB := dbm.NewMemDB()
-	state := sm.MakeGenesisStateFromFile(stateDB, config.GenesisFile())
+	state, _ := sm.MakeGenesisStateFromFile(stateDB, config.GenesisFile())
 	state.SetLogger(log.TestingLogger().With("module", "state"))
 	privValidator := loadPrivValidator(config)
 	cs := newConsensusState(state, privValidator, dummy.NewDummyApplication())
@@ -338,7 +338,7 @@ func randConsensusNet(nValidators int, testName string, tickerFunc func() Timeou
 	logger := consensusLogger()
 	for i := 0; i < nValidators; i++ {
 		db := dbm.NewMemDB() // each state needs its own db
-		state := sm.MakeGenesisState(db, genDoc)
+		state, _ := sm.MakeGenesisState(db, genDoc)
 		state.SetLogger(logger.With("module", "state", "validator", i))
 		state.Save()
 		thisConfig := ResetConfig(Fmt("%s_%d", testName, i))
@@ -359,18 +359,17 @@ func randConsensusNetWithPeers(nValidators, nPeers int, testName string, tickerF
 	css := make([]*ConsensusState, nPeers)
 	for i := 0; i < nPeers; i++ {
 		db := dbm.NewMemDB() // each state needs its own db
-		state := sm.MakeGenesisState(db, genDoc)
+		state, _ := sm.MakeGenesisState(db, genDoc)
 		state.SetLogger(log.TestingLogger().With("module", "state"))
 		state.Save()
 		thisConfig := ResetConfig(Fmt("%s_%d", testName, i))
 		ensureDir(path.Dir(thisConfig.Consensus.WalFile()), 0700) // dir for wal
-		var privVal *types.PrivValidator
+		var privVal types.PrivValidator
 		if i < nValidators {
 			privVal = privVals[i]
 		} else {
-			privVal = types.GenPrivValidator()
 			_, tempFilePath := Tempfile("priv_validator_")
-			privVal.SetFile(tempFilePath)
+			privVal = types.GenPrivValidatorFS(tempFilePath)
 		}
 
 		css[i] = newConsensusStateWithConfig(thisConfig, state, privVal, appFunc())
@@ -380,9 +379,9 @@ func randConsensusNetWithPeers(nValidators, nPeers int, testName string, tickerF
 	return css
 }
 
-func getSwitchIndex(switches []*p2p.Switch, peer *p2p.Peer) int {
+func getSwitchIndex(switches []*p2p.Switch, peer p2p.Peer) int {
 	for i, s := range switches {
-		if bytes.Equal(peer.NodeInfo.PubKey.Address(), s.NodeInfo().PubKey.Address()) {
+		if bytes.Equal(peer.NodeInfo().PubKey.Address(), s.NodeInfo().PubKey.Address()) {
 			return i
 		}
 	}
@@ -393,14 +392,14 @@ func getSwitchIndex(switches []*p2p.Switch, peer *p2p.Peer) int {
 //-------------------------------------------------------------------------------
 // genesis
 
-func randGenesisDoc(numValidators int, randPower bool, minPower int64) (*types.GenesisDoc, []*types.PrivValidator) {
+func randGenesisDoc(numValidators int, randPower bool, minPower int64) (*types.GenesisDoc, []*types.PrivValidatorFS) {
 	validators := make([]types.GenesisValidator, numValidators)
-	privValidators := make([]*types.PrivValidator, numValidators)
+	privValidators := make([]*types.PrivValidatorFS, numValidators)
 	for i := 0; i < numValidators; i++ {
 		val, privVal := types.RandValidator(randPower, minPower)
 		validators[i] = types.GenesisValidator{
 			PubKey: val.PubKey,
-			Amount: val.VotingPower,
+			Power:  val.VotingPower,
 		}
 		privValidators[i] = privVal
 	}
@@ -412,10 +411,10 @@ func randGenesisDoc(numValidators int, randPower bool, minPower int64) (*types.G
 	}, privValidators
 }
 
-func randGenesisState(numValidators int, randPower bool, minPower int64) (*sm.State, []*types.PrivValidator) {
+func randGenesisState(numValidators int, randPower bool, minPower int64) (*sm.State, []*types.PrivValidatorFS) {
 	genDoc, privValidators := randGenesisDoc(numValidators, randPower, minPower)
 	db := dbm.NewMemDB()
-	s0 := sm.MakeGenesisState(db, genDoc)
+	s0, _ := sm.MakeGenesisState(db, genDoc)
 	s0.SetLogger(log.TestingLogger().With("module", "state"))
 	s0.Save()
 	return s0, privValidators
diff --git a/consensus/height_vote_set_test.go b/consensus/height_vote_set_test.go
index 29751b40a..7e03e40f5 100644
--- a/consensus/height_vote_set_test.go
+++ b/consensus/height_vote_set_test.go
@@ -44,10 +44,10 @@ func TestPeerCatchupRounds(t *testing.T) {
 
 }
 
-func makeVoteHR(t *testing.T, height, round int, privVals []*types.PrivValidator, valIndex int) *types.Vote {
+func makeVoteHR(t *testing.T, height, round int, privVals []*types.PrivValidatorFS, valIndex int) *types.Vote {
 	privVal := privVals[valIndex]
 	vote := &types.Vote{
-		ValidatorAddress: privVal.Address,
+		ValidatorAddress: privVal.GetAddress(),
 		ValidatorIndex:   valIndex,
 		Height:           height,
 		Round:            round,
diff --git a/consensus/mempool_test.go b/consensus/mempool_test.go
index 0f726b39e..f17d19f52 100644
--- a/consensus/mempool_test.go
+++ b/consensus/mempool_test.go
@@ -183,7 +183,7 @@ func NewCounterApplication() *CounterApplication {
 	return &CounterApplication{}
 }
 
-func (app *CounterApplication) Info() abci.ResponseInfo {
+func (app *CounterApplication) Info(req abci.RequestInfo) abci.ResponseInfo {
 	return abci.ResponseInfo{Data: Fmt("txs:%v", app.txCount)}
 }
 
diff --git a/consensus/reactor.go b/consensus/reactor.go
index f4107c653..59cbfea76 100644
--- a/consensus/reactor.go
+++ b/consensus/reactor.go
@@ -120,14 +120,14 @@ func (conR *ConsensusReactor) GetChannels() []*p2p.ChannelDescriptor {
 }
 
 // AddPeer implements Reactor
-func (conR *ConsensusReactor) AddPeer(peer *p2p.Peer) {
+func (conR *ConsensusReactor) AddPeer(peer p2p.Peer) {
 	if !conR.IsRunning() {
 		return
 	}
 
 	// Create peerState for peer
-	peerState := NewPeerState(peer)
-	peer.Data.Set(types.PeerStateKey, peerState)
+	peerState := NewPeerState(peer).SetLogger(conR.Logger)
+	peer.Set(types.PeerStateKey, peerState)
 
 	// Begin routines for this peer.
 	go conR.gossipDataRoutine(peer, peerState)
@@ -142,12 +142,12 @@ func (conR *ConsensusReactor) AddPeer(peer *p2p.Peer) {
 }
 
 // RemovePeer implements Reactor
-func (conR *ConsensusReactor) RemovePeer(peer *p2p.Peer, reason interface{}) {
+func (conR *ConsensusReactor) RemovePeer(peer p2p.Peer, reason interface{}) {
 	if !conR.IsRunning() {
 		return
 	}
 	// TODO
-	//peer.Data.Get(PeerStateKey).(*PeerState).Disconnect()
+	//peer.Get(PeerStateKey).(*PeerState).Disconnect()
 }
 
 // Receive implements Reactor
@@ -156,7 +156,7 @@ func (conR *ConsensusReactor) RemovePeer(peer *p2p.Peer, reason interface{}) {
 // Peer state updates can happen in parallel, but processing of
 // proposals, block parts, and votes are ordered by the receiveRoutine
 // NOTE: blocks on consensus state for proposals, block parts, and votes
-func (conR *ConsensusReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte) {
+func (conR *ConsensusReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
 	if !conR.IsRunning() {
 		conR.Logger.Debug("Receive", "src", src, "chId", chID, "bytes", msgBytes)
 		return
@@ -171,7 +171,7 @@ func (conR *ConsensusReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte)
 	conR.Logger.Debug("Receive", "src", src, "chId", chID, "msg", msg)
 
 	// Get peer states
-	ps := src.Data.Get(types.PeerStateKey).(*PeerState)
+	ps := src.Get(types.PeerStateKey).(*PeerState)
 
 	switch chID {
 	case StateChannel:
@@ -191,7 +191,7 @@ func (conR *ConsensusReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte)
 				return
 			}
 			// Peer claims to have a maj23 for some BlockID at H,R,S,
-			votes.SetPeerMaj23(msg.Round, msg.Type, ps.Peer.Key, msg.BlockID)
+			votes.SetPeerMaj23(msg.Round, msg.Type, ps.Peer.Key(), msg.BlockID)
 			// Respond with a VoteSetBitsMessage showing which votes we have.
 			// (and consequently shows which we don't have)
 			var ourVotes *cmn.BitArray
@@ -228,12 +228,12 @@ func (conR *ConsensusReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte)
 		switch msg := msg.(type) {
 		case *ProposalMessage:
 			ps.SetHasProposal(msg.Proposal)
-			conR.conS.peerMsgQueue <- msgInfo{msg, src.Key}
+			conR.conS.peerMsgQueue <- msgInfo{msg, src.Key()}
 		case *ProposalPOLMessage:
 			ps.ApplyProposalPOLMessage(msg)
 		case *BlockPartMessage:
 			ps.SetHasProposalBlockPart(msg.Height, msg.Round, msg.Part.Index)
-			conR.conS.peerMsgQueue <- msgInfo{msg, src.Key}
+			conR.conS.peerMsgQueue <- msgInfo{msg, src.Key()}
 		default:
 			conR.Logger.Error(cmn.Fmt("Unknown message type %v", reflect.TypeOf(msg)))
 		}
@@ -253,7 +253,7 @@ func (conR *ConsensusReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte)
 			ps.EnsureVoteBitArrays(height-1, lastCommitSize)
 			ps.SetHasVote(msg.Vote)
 
-			cs.peerMsgQueue <- msgInfo{msg, src.Key}
+			cs.peerMsgQueue <- msgInfo{msg, src.Key()}
 
 		default:
 			// don't punish (leave room for soft upgrades)
@@ -367,7 +367,7 @@ func (conR *ConsensusReactor) broadcastHasVoteMessage(vote *types.Vote) {
 	/*
 		// TODO: Make this broadcast more selective.
 		for _, peer := range conR.Switch.Peers().List() {
-			ps := peer.Data.Get(PeerStateKey).(*PeerState)
+			ps := peer.Get(PeerStateKey).(*PeerState)
 			prs := ps.GetRoundState()
 			if prs.Height == vote.Height {
 				// TODO: Also filter on round?
@@ -399,7 +399,7 @@ func makeRoundStepMessages(rs *RoundState) (nrsMsg *NewRoundStepMessage, csMsg *
 	return
 }
 
-func (conR *ConsensusReactor) sendNewRoundStepMessages(peer *p2p.Peer) {
+func (conR *ConsensusReactor) sendNewRoundStepMessages(peer p2p.Peer) {
 	rs := conR.conS.GetRoundState()
 	nrsMsg, csMsg := makeRoundStepMessages(rs)
 	if nrsMsg != nil {
@@ -410,7 +410,7 @@ func (conR *ConsensusReactor) sendNewRoundStepMessages(peer *p2p.Peer) {
 	}
 }
 
-func (conR *ConsensusReactor) gossipDataRoutine(peer *p2p.Peer, ps *PeerState) {
+func (conR *ConsensusReactor) gossipDataRoutine(peer p2p.Peer, ps *PeerState) {
 	logger := conR.Logger.With("peer", peer)
 
 OUTER_LOOP:
@@ -492,7 +492,7 @@ OUTER_LOOP:
 }
 
 func (conR *ConsensusReactor) gossipDataForCatchup(logger log.Logger, rs *RoundState,
-	prs *PeerRoundState, ps *PeerState, peer *p2p.Peer) {
+	prs *PeerRoundState, ps *PeerState, peer p2p.Peer) {
 
 	if index, ok := prs.ProposalBlockParts.Not().PickRandom(); ok {
 		// Ensure that the peer's PartSetHeader is correct
@@ -534,7 +534,7 @@ func (conR *ConsensusReactor) gossipDataForCatchup(logger log.Logger, rs *RoundS
 	}
 }
 
-func (conR *ConsensusReactor) gossipVotesRoutine(peer *p2p.Peer, ps *PeerState) {
+func (conR *ConsensusReactor) gossipVotesRoutine(peer p2p.Peer, ps *PeerState) {
 	logger := conR.Logger.With("peer", peer)
 
 	// Simple hack to throttle logs upon sleep.
@@ -644,7 +644,7 @@ func (conR *ConsensusReactor) gossipVotesForHeight(logger log.Logger, rs *RoundS
 
 // NOTE: `queryMaj23Routine` has a simple crude design since it only comes
 // into play for liveness when there's a signature DDoS attack happening.
-func (conR *ConsensusReactor) queryMaj23Routine(peer *p2p.Peer, ps *PeerState) {
+func (conR *ConsensusReactor) queryMaj23Routine(peer p2p.Peer, ps *PeerState) {
 	logger := conR.Logger.With("peer", peer)
 
 OUTER_LOOP:
@@ -743,7 +743,7 @@ func (conR *ConsensusReactor) StringIndented(indent string) string {
 	s := "ConsensusReactor{\n"
 	s += indent + "  " + conR.conS.StringIndented(indent+"  ") + "\n"
 	for _, peer := range conR.Switch.Peers().List() {
-		ps := peer.Data.Get(types.PeerStateKey).(*PeerState)
+		ps := peer.Get(types.PeerStateKey).(*PeerState)
 		s += indent + "  " + ps.StringIndented(indent+"  ") + "\n"
 	}
 	s += indent + "}"
@@ -808,16 +808,18 @@ var (
 // PeerState contains the known state of a peer, including its connection
 // and threadsafe access to its PeerRoundState.
 type PeerState struct {
-	Peer *p2p.Peer
+	Peer   p2p.Peer
+	logger log.Logger
 
 	mtx sync.Mutex
 	PeerRoundState
 }
 
 // NewPeerState returns a new PeerState for the given Peer
-func NewPeerState(peer *p2p.Peer) *PeerState {
+func NewPeerState(peer p2p.Peer) *PeerState {
 	return &PeerState{
-		Peer: peer,
+		Peer:   peer,
+		logger: log.NewNopLogger(),
 		PeerRoundState: PeerRoundState{
 			Round:              -1,
 			ProposalPOLRound:   -1,
@@ -827,6 +829,11 @@ func NewPeerState(peer *p2p.Peer) *PeerState {
 	}
 }
 
+func (ps *PeerState) SetLogger(logger log.Logger) *PeerState {
+	ps.logger = logger
+	return ps
+}
+
 // GetRoundState returns an atomic snapshot of the PeerRoundState.
 // There's no point in mutating it since it won't change PeerState.
 func (ps *PeerState) GetRoundState() *PeerRoundState {
@@ -1025,7 +1032,7 @@ func (ps *PeerState) SetHasVote(vote *types.Vote) {
 }
 
 func (ps *PeerState) setHasVote(height int, round int, type_ byte, index int) {
-	logger := ps.Peer.Logger.With("peerRound", ps.Round, "height", height, "round", round)
+	logger := ps.logger.With("peerRound", ps.Round, "height", height, "round", round)
 	logger.Debug("setHasVote(LastCommit)", "lastCommit", ps.LastCommit, "index", index)
 
 	// NOTE: some may be nil BitArrays -> no side effects.
@@ -1163,7 +1170,7 @@ func (ps *PeerState) StringIndented(indent string) string {
 %s  Key %v
 %s  PRS %v
 %s}`,
-		indent, ps.Peer.Key,
+		indent, ps.Peer.Key(),
 		indent, ps.PeerRoundState.StringIndented(indent+"  "),
 		indent)
 }
diff --git a/consensus/reactor_test.go b/consensus/reactor_test.go
index b1f9a0a5b..623a65413 100644
--- a/consensus/reactor_test.go
+++ b/consensus/reactor_test.go
@@ -132,7 +132,7 @@ func TestVotingPowerChange(t *testing.T) {
 	//---------------------------------------------------------------------------
 	t.Log("---------------------------- Testing changing the voting power of one validator a few times")
 
-	val1PubKey := css[0].privValidator.(*types.PrivValidator).PubKey
+	val1PubKey := css[0].privValidator.GetPubKey()
 	updateValidatorTx := dummy.MakeValSetChangeTx(val1PubKey.Bytes(), 25)
 	previousTotalVotingPower := css[0].GetRoundState().LastValidators.TotalVotingPower()
 
@@ -193,7 +193,7 @@ func TestValidatorSetChanges(t *testing.T) {
 	//---------------------------------------------------------------------------
 	t.Log("---------------------------- Testing adding one validator")
 
-	newValidatorPubKey1 := css[nVals].privValidator.(*types.PrivValidator).PubKey
+	newValidatorPubKey1 := css[nVals].privValidator.GetPubKey()
 	newValidatorTx1 := dummy.MakeValSetChangeTx(newValidatorPubKey1.Bytes(), uint64(testMinPower))
 
 	// wait till everyone makes block 2
@@ -219,7 +219,7 @@ func TestValidatorSetChanges(t *testing.T) {
 	//---------------------------------------------------------------------------
 	t.Log("---------------------------- Testing changing the voting power of one validator")
 
-	updateValidatorPubKey1 := css[nVals].privValidator.(*types.PrivValidator).PubKey
+	updateValidatorPubKey1 := css[nVals].privValidator.GetPubKey()
 	updateValidatorTx1 := dummy.MakeValSetChangeTx(updateValidatorPubKey1.Bytes(), 25)
 	previousTotalVotingPower := css[nVals].GetRoundState().LastValidators.TotalVotingPower()
 
@@ -235,10 +235,10 @@ func TestValidatorSetChanges(t *testing.T) {
 	//---------------------------------------------------------------------------
 	t.Log("---------------------------- Testing adding two validators at once")
 
-	newValidatorPubKey2 := css[nVals+1].privValidator.(*types.PrivValidator).PubKey
+	newValidatorPubKey2 := css[nVals+1].privValidator.GetPubKey()
 	newValidatorTx2 := dummy.MakeValSetChangeTx(newValidatorPubKey2.Bytes(), uint64(testMinPower))
 
-	newValidatorPubKey3 := css[nVals+2].privValidator.(*types.PrivValidator).PubKey
+	newValidatorPubKey3 := css[nVals+2].privValidator.GetPubKey()
 	newValidatorTx3 := dummy.MakeValSetChangeTx(newValidatorPubKey3.Bytes(), uint64(testMinPower))
 
 	waitForAndValidateBlock(t, nPeers, activeVals, eventChans, css, newValidatorTx2, newValidatorTx3)
diff --git a/consensus/replay.go b/consensus/replay.go
index 0c7c27e90..c5cb42191 100644
--- a/consensus/replay.go
+++ b/consensus/replay.go
@@ -19,6 +19,7 @@ import (
 	"github.com/tendermint/tendermint/proxy"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/types"
+	"github.com/tendermint/tendermint/version"
 )
 
 // Functionality to replay blocks and messages on recovery from a crash.
@@ -115,35 +116,13 @@ func (cs *ConsensusState) catchupReplay(csHeight int) error {
 	gr, found, err = cs.wal.group.Search("#ENDHEIGHT: ", makeHeightSearchFunc(csHeight-1))
 	if err == io.EOF {
 		cs.Logger.Error("Replay: wal.group.Search returned EOF", "#ENDHEIGHT", csHeight-1)
-		// if we upgraded from 0.9 to 0.9.1, we may have #HEIGHT instead
-		// TODO (0.10.0): remove this
-		gr, found, err = cs.wal.group.Search("#HEIGHT: ", makeHeightSearchFunc(csHeight))
-		if err == io.EOF {
-			cs.Logger.Error("Replay: wal.group.Search returned EOF", "#HEIGHT", csHeight)
-			return nil
-		} else if err != nil {
-			return err
-		}
 	} else if err != nil {
 		return err
 	} else {
 		defer gr.Close()
 	}
 	if !found {
-		// if we upgraded from 0.9 to 0.9.1, we may have #HEIGHT instead
-		// TODO (0.10.0): remove this
-		gr, _, err = cs.wal.group.Search("#HEIGHT: ", makeHeightSearchFunc(csHeight))
-		if err == io.EOF {
-			cs.Logger.Error("Replay: wal.group.Search returned EOF", "#HEIGHT", csHeight)
-			return nil
-		} else if err != nil {
-			return err
-		} else {
-			defer gr.Close()
-		}
-
-		// TODO (0.10.0): uncomment
-		// return errors.New(cmn.Fmt("Cannot replay height %d. WAL does not contain #ENDHEIGHT for %d.", csHeight, csHeight-1))
+		return errors.New(cmn.Fmt("Cannot replay height %d. WAL does not contain #ENDHEIGHT for %d.", csHeight, csHeight-1))
 	}
 
 	cs.Logger.Info("Catchup by replaying consensus messages", "height", csHeight)
@@ -221,7 +200,7 @@ func (h *Handshaker) NBlocks() int {
 // TODO: retry the handshake/replay if it fails ?
 func (h *Handshaker) Handshake(proxyApp proxy.AppConns) error {
 	// handshake is done via info request on the query conn
-	res, err := proxyApp.Query().InfoSync()
+	res, err := proxyApp.Query().InfoSync(abci.RequestInfo{version.Version})
 	if err != nil {
 		return errors.New(cmn.Fmt("Error calling Info: %v", err))
 	}
@@ -257,7 +236,7 @@ func (h *Handshaker) ReplayBlocks(appHash []byte, appBlockHeight int, proxyApp p
 	// If appBlockHeight == 0 it means that we are at genesis and hence should send InitChain
 	if appBlockHeight == 0 {
 		validators := types.TM2PB.Validators(h.state.Validators)
-		proxyApp.Consensus().InitChainSync(validators)
+		proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators})
 	}
 
 	// First handle edge cases and constraints on the storeBlockHeight
@@ -324,8 +303,11 @@ func (h *Handshaker) ReplayBlocks(appHash []byte, appBlockHeight int, proxyApp p
 func (h *Handshaker) replayBlocks(proxyApp proxy.AppConns, appBlockHeight, storeBlockHeight int, mutateState bool) ([]byte, error) {
 	// App is further behind than it should be, so we need to replay blocks.
 	// We replay all blocks from appBlockHeight+1.
+	//
 	// Note that we don't have an old version of the state,
 	// so we by-pass state validation/mutation using sm.ExecCommitBlock.
+	// This also means we won't be saving validator sets if they change during this period.
+	//
 	// If mutateState == true, the final block is replayed with h.replayBlock()
 
 	var appHash []byte
diff --git a/consensus/replay_file.go b/consensus/replay_file.go
index 39ce47c5e..1182aaf04 100644
--- a/consensus/replay_file.go
+++ b/consensus/replay_file.go
@@ -241,12 +241,15 @@ func newConsensusStateForReplay(config cfg.BaseConfig, csConfig *cfg.ConsensusCo
 
 	// Get State
 	stateDB := dbm.NewDB("state", config.DBBackend, config.DBDir())
-	state := sm.MakeGenesisStateFromFile(stateDB, config.GenesisFile())
+	state, err := sm.MakeGenesisStateFromFile(stateDB, config.GenesisFile())
+	if err != nil {
+		cmn.Exit(err.Error())
+	}
 
 	// Create proxyAppConn connection (consensus, mempool, query)
 	clientCreator := proxy.DefaultClientCreator(config.ProxyApp, config.ABCI, config.DBDir())
 	proxyApp := proxy.NewAppConns(clientCreator, NewHandshaker(state, blockStore))
-	_, err := proxyApp.Start()
+	_, err = proxyApp.Start()
 	if err != nil {
 		cmn.Exit(cmn.Fmt("Error starting proxy app conns: %v", err))
 	}
diff --git a/consensus/replay_test.go b/consensus/replay_test.go
index 78cdaf7bc..c478a0958 100644
--- a/consensus/replay_test.go
+++ b/consensus/replay_test.go
@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"github.com/tendermint/abci/example/dummy"
+	abci "github.com/tendermint/abci/types"
 	crypto "github.com/tendermint/go-crypto"
 	wire "github.com/tendermint/go-wire"
 	cmn "github.com/tendermint/tmlibs/common"
@@ -162,8 +163,8 @@ LOOP:
 	cs.Wait()
 }
 
-func toPV(pv PrivValidator) *types.PrivValidator {
-	return pv.(*types.PrivValidator)
+func toPV(pv types.PrivValidator) *types.PrivValidatorFS {
+	return pv.(*types.PrivValidatorFS)
 }
 
 func setupReplayTest(t *testing.T, thisCase *testCase, nLines int, crashAfter bool) (*ConsensusState, chan interface{}, string, string) {
@@ -267,8 +268,6 @@ func testReplayCrashBeforeWriteVote(t *testing.T, thisCase *testCase, lineNum in
 var (
 	NUM_BLOCKS = 6 // number of blocks in the test_data/many_blocks.cswal
 	mempool    = types.MockMempool{}
-
-	testPartSize int
 )
 
 //---------------------------------------
@@ -319,8 +318,7 @@ func testHandshakeReplay(t *testing.T, nBlocks int, mode uint) {
 	walFile := writeWAL(string(walBody))
 	config.Consensus.SetWalFile(walFile)
 
-	privVal := types.LoadPrivValidator(config.PrivValidatorFile())
-	testPartSize = config.Consensus.BlockPartSize
+	privVal := types.LoadPrivValidatorFS(config.PrivValidatorFile())
 
 	wal, err := NewWAL(walFile, false)
 	if err != nil {
@@ -335,7 +333,7 @@ func testHandshakeReplay(t *testing.T, nBlocks int, mode uint) {
 		t.Fatalf(err.Error())
 	}
 
-	state, store := stateAndStore(config, privVal.PubKey)
+	state, store := stateAndStore(config, privVal.GetPubKey())
 	store.chain = chain
 	store.commits = commits
 
@@ -349,7 +347,7 @@ func testHandshakeReplay(t *testing.T, nBlocks int, mode uint) {
 		// run nBlocks against a new client to build up the app state.
 		// use a throwaway tendermint state
 		proxyApp := proxy.NewAppConns(clientCreator2, nil)
-		state, _ := stateAndStore(config, privVal.PubKey)
+		state, _ := stateAndStore(config, privVal.GetPubKey())
 		buildAppStateFromChain(proxyApp, state, chain, nBlocks, mode)
 	}
 
@@ -361,7 +359,7 @@ func testHandshakeReplay(t *testing.T, nBlocks int, mode uint) {
 	}
 
 	// get the latest app hash from the app
-	res, err := proxyApp.Query().InfoSync()
+	res, err := proxyApp.Query().InfoSync(abci.RequestInfo{""})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -384,6 +382,7 @@ func testHandshakeReplay(t *testing.T, nBlocks int, mode uint) {
 }
 
 func applyBlock(st *sm.State, blk *types.Block, proxyApp proxy.AppConns) {
+	testPartSize := st.Params().BlockPartSizeBytes
 	err := st.ApplyBlock(nil, proxyApp.Consensus(), blk, blk.MakePartSet(testPartSize).Header(), mempool)
 	if err != nil {
 		panic(err)
@@ -398,7 +397,7 @@ func buildAppStateFromChain(proxyApp proxy.AppConns,
 	}
 
 	validators := types.TM2PB.Validators(state.Validators)
-	proxyApp.Consensus().InitChainSync(validators)
+	proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators})
 
 	defer proxyApp.Stop()
 	switch mode {
@@ -432,7 +431,7 @@ func buildTMStateFromChain(config *cfg.Config, state *sm.State, chain []*types.B
 	defer proxyApp.Stop()
 
 	validators := types.TM2PB.Validators(state.Validators)
-	proxyApp.Consensus().InitChainSync(validators)
+	proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators})
 
 	var latestAppHash []byte
 
@@ -503,7 +502,7 @@ func makeBlockchainFromWAL(wal *WAL) ([]*types.Block, []*types.Commit, error) {
 			// if its not the first one, we have a full block
 			if blockParts != nil {
 				var n int
-				block := wire.ReadBinary(&types.Block{}, blockParts.GetReader(), types.MaxBlockSize, &n, &err).(*types.Block)
+				block := wire.ReadBinary(&types.Block{}, blockParts.GetReader(), 0, &n, &err).(*types.Block)
 				blocks = append(blocks, block)
 			}
 			blockParts = types.NewPartSetFromHeader(*p)
@@ -524,7 +523,7 @@ func makeBlockchainFromWAL(wal *WAL) ([]*types.Block, []*types.Commit, error) {
 	}
 	// grab the last block too
 	var n int
-	block := wire.ReadBinary(&types.Block{}, blockParts.GetReader(), types.MaxBlockSize, &n, &err).(*types.Block)
+	block := wire.ReadBinary(&types.Block{}, blockParts.GetReader(), 0, &n, &err).(*types.Block)
 	blocks = append(blocks, block)
 	return blocks, commits, nil
 }
@@ -560,10 +559,10 @@ func readPieceFromWAL(msgBytes []byte) (interface{}, error) {
 // fresh state and mock store
 func stateAndStore(config *cfg.Config, pubKey crypto.PubKey) (*sm.State, *mockBlockStore) {
 	stateDB := dbm.NewMemDB()
-	state := sm.MakeGenesisStateFromFile(stateDB, config.GenesisFile())
+	state, _ := sm.MakeGenesisStateFromFile(stateDB, config.GenesisFile())
 	state.SetLogger(log.TestingLogger().With("module", "state"))
 
-	store := NewMockBlockStore(config)
+	store := NewMockBlockStore(config, state.Params())
 	return state, store
 }
 
@@ -572,13 +571,14 @@ func stateAndStore(config *cfg.Config, pubKey crypto.PubKey) (*sm.State, *mockBl
 
 type mockBlockStore struct {
 	config  *cfg.Config
+	params  types.ConsensusParams
 	chain   []*types.Block
 	commits []*types.Commit
 }
 
 // TODO: NewBlockStore(db.NewMemDB) ...
-func NewMockBlockStore(config *cfg.Config) *mockBlockStore {
-	return &mockBlockStore{config, nil, nil}
+func NewMockBlockStore(config *cfg.Config, params types.ConsensusParams) *mockBlockStore {
+	return &mockBlockStore{config, params, nil, nil}
 }
 
 func (bs *mockBlockStore) Height() int                       { return len(bs.chain) }
@@ -586,7 +586,7 @@ func (bs *mockBlockStore) LoadBlock(height int) *types.Block { return bs.chain[h
 func (bs *mockBlockStore) LoadBlockMeta(height int) *types.BlockMeta {
 	block := bs.chain[height-1]
 	return &types.BlockMeta{
-		BlockID: types.BlockID{block.Hash(), block.MakePartSet(bs.config.Consensus.BlockPartSize).Header()},
+		BlockID: types.BlockID{block.Hash(), block.MakePartSet(bs.params.BlockPartSizeBytes).Header()},
 		Header:  block.Header,
 	}
 }
diff --git a/consensus/state.go b/consensus/state.go
index f6ee5d45e..648fc0559 100644
--- a/consensus/state.go
+++ b/consensus/state.go
@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"path"
+	"path/filepath"
 	"reflect"
 	"sync"
 	"time"
@@ -180,14 +180,6 @@ func (ti *timeoutInfo) String() string {
 	return fmt.Sprintf("%v ; %d/%d %v", ti.Duration, ti.Height, ti.Round, ti.Step)
 }
 
-// PrivValidator is a validator that can sign votes and proposals.
-type PrivValidator interface {
-	GetAddress() []byte
-	SignVote(chainID string, vote *types.Vote) error
-	SignProposal(chainID string, proposal *types.Proposal) error
-	SignHeartbeat(chainID string, heartbeat *types.Heartbeat) error
-}
-
 // ConsensusState handles execution of the consensus algorithm.
 // It processes votes and proposals, and upon reaching agreement,
 // commits blocks to the chain and executes them against the application.
@@ -197,7 +189,7 @@ type ConsensusState struct {
 
 	// config details
 	config        *cfg.ConsensusConfig
-	privValidator PrivValidator // for signing votes
+	privValidator types.PrivValidator // for signing votes
 
 	// services for creating and executing blocks
 	proxyAppConn proxy.AppConnConsensus
@@ -308,7 +300,7 @@ func (cs *ConsensusState) GetValidators() (int, []*types.Validator) {
 }
 
 // SetPrivValidator sets the private validator account for signing votes.
-func (cs *ConsensusState) SetPrivValidator(priv PrivValidator) {
+func (cs *ConsensusState) SetPrivValidator(priv types.PrivValidator) {
 	cs.mtx.Lock()
 	defer cs.mtx.Unlock()
 	cs.privValidator = priv
@@ -394,7 +386,7 @@ func (cs *ConsensusState) Wait() {
 
 // OpenWAL opens a file to log all consensus messages and timeouts for deterministic accountability
 func (cs *ConsensusState) OpenWAL(walFile string) (err error) {
-	err = cmn.EnsureDir(path.Dir(walFile), 0700)
+	err = cmn.EnsureDir(filepath.Dir(walFile), 0700)
 	if err != nil {
 		cs.Logger.Error("Error ensuring ConsensusState wal dir", "err", err.Error())
 		return err
@@ -983,7 +975,8 @@ func (cs *ConsensusState) createProposalBlock() (block *types.Block, blockParts
 	txs := cs.mempool.Reap(cs.config.MaxBlockSizeTxs)
 
 	return types.MakeBlock(cs.Height, cs.state.ChainID, txs, commit,
-		cs.state.LastBlockID, cs.state.Validators.Hash(), cs.state.AppHash, cs.config.BlockPartSize)
+		cs.state.LastBlockID, cs.state.Validators.Hash(),
+		cs.state.AppHash, cs.state.Params().BlockPartSizeBytes)
 }
 
 // Enter: `timeoutPropose` after entering Propose.
@@ -1417,7 +1410,8 @@ func (cs *ConsensusState) addProposalBlockPart(height int, part *types.Part, ver
 		// Added and completed!
 		var n int
 		var err error
-		cs.ProposalBlock = wire.ReadBinary(&types.Block{}, cs.ProposalBlockParts.GetReader(), types.MaxBlockSize, &n, &err).(*types.Block)
+		cs.ProposalBlock = wire.ReadBinary(&types.Block{}, cs.ProposalBlockParts.GetReader(),
+			cs.state.Params().BlockSizeParams.MaxBytes, &n, &err).(*types.Block)
 		// NOTE: it's possible to receive complete proposal blocks for future rounds without having the proposal
 		cs.Logger.Info("Received complete proposal block", "height", cs.ProposalBlock.Height, "hash", cs.ProposalBlock.Hash())
 		if cs.Step == RoundStepPropose && cs.isProposalComplete() {
diff --git a/consensus/state_test.go b/consensus/state_test.go
index 81ef016be..c4a6769e9 100644
--- a/consensus/state_test.go
+++ b/consensus/state_test.go
@@ -79,7 +79,7 @@ func TestProposerSelection0(t *testing.T) {
 	<-newRoundCh
 
 	prop = cs1.GetRoundState().Validators.GetProposer()
-	if !bytes.Equal(prop.Address, vss[1].Address) {
+	if !bytes.Equal(prop.Address, vss[1].GetAddress()) {
 		panic(Fmt("expected proposer to be validator %d. Got %X", 1, prop.Address))
 	}
 }
@@ -100,7 +100,7 @@ func TestProposerSelection2(t *testing.T) {
 	// everyone just votes nil. we get a new proposer each round
 	for i := 0; i < len(vss); i++ {
 		prop := cs1.GetRoundState().Validators.GetProposer()
-		if !bytes.Equal(prop.Address, vss[(i+2)%len(vss)].Address) {
+		if !bytes.Equal(prop.Address, vss[(i+2)%len(vss)].GetAddress()) {
 			panic(Fmt("expected proposer to be validator %d. Got %X", (i+2)%len(vss), prop.Address))
 		}
 
@@ -180,7 +180,7 @@ func TestBadProposal(t *testing.T) {
 	height, round := cs1.Height, cs1.Round
 	vs2 := vss[1]
 
-	partSize := config.Consensus.BlockPartSize
+	partSize := cs1.state.Params().BlockPartSizeBytes
 
 	proposalCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringCompleteProposal(), 1)
 	voteCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringVote(), 1)
@@ -327,7 +327,7 @@ func TestLockNoPOL(t *testing.T) {
 	vs2 := vss[1]
 	height := cs1.Height
 
-	partSize := config.Consensus.BlockPartSize
+	partSize := cs1.state.Params().BlockPartSizeBytes
 
 	timeoutProposeCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringTimeoutPropose(), 1)
 	timeoutWaitCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringTimeoutWait(), 1)
@@ -493,7 +493,7 @@ func TestLockPOLRelock(t *testing.T) {
 	cs1, vss := randConsensusState(4)
 	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
 
-	partSize := config.Consensus.BlockPartSize
+	partSize := cs1.state.Params().BlockPartSizeBytes
 
 	timeoutProposeCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringTimeoutPropose(), 1)
 	timeoutWaitCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringTimeoutWait(), 1)
@@ -502,8 +502,6 @@ func TestLockPOLRelock(t *testing.T) {
 	newRoundCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringNewRound(), 1)
 	newBlockCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringNewBlockHeader(), 1)
 
-	t.Logf("vs2 last round %v", vs2.PrivValidator.LastRound)
-
 	// everything done from perspective of cs1
 
 	/*
@@ -608,7 +606,7 @@ func TestLockPOLUnlock(t *testing.T) {
 	cs1, vss := randConsensusState(4)
 	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
 
-	partSize := config.Consensus.BlockPartSize
+	partSize := cs1.state.Params().BlockPartSizeBytes
 
 	proposalCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringCompleteProposal(), 1)
 	timeoutProposeCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringTimeoutPropose(), 1)
@@ -703,7 +701,7 @@ func TestLockPOLSafety1(t *testing.T) {
 	cs1, vss := randConsensusState(4)
 	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
 
-	partSize := config.Consensus.BlockPartSize
+	partSize := cs1.state.Params().BlockPartSizeBytes
 
 	proposalCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringCompleteProposal(), 1)
 	timeoutProposeCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringTimeoutPropose(), 1)
@@ -824,7 +822,7 @@ func TestLockPOLSafety2(t *testing.T) {
 	cs1, vss := randConsensusState(4)
 	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
 
-	partSize := config.Consensus.BlockPartSize
+	partSize := cs1.state.Params().BlockPartSizeBytes
 
 	proposalCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringCompleteProposal(), 1)
 	timeoutProposeCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringTimeoutPropose(), 1)
@@ -999,7 +997,7 @@ func TestHalt1(t *testing.T) {
 	cs1, vss := randConsensusState(4)
 	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
 
-	partSize := config.Consensus.BlockPartSize
+	partSize := cs1.state.Params().BlockPartSizeBytes
 
 	proposalCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringCompleteProposal(), 1)
 	timeoutWaitCh := subscribeToEvent(cs1.evsw, "tester", types.EventStringTimeoutWait(), 1)
diff --git a/docs/abci-cli.rst b/docs/abci-cli.rst
index 371ec0cba..5ca672c8a 100644
--- a/docs/abci-cli.rst
+++ b/docs/abci-cli.rst
@@ -1,5 +1,5 @@
-Using the abci-cli
-==================
+Using ABCI-CLI
+==============
 
 To facilitate testing and debugging of ABCI servers and simple apps, we
 built a CLI, the ``abci-cli``, for sending ABCI messages from the
diff --git a/docs/app-architecture.rst b/docs/app-architecture.rst
index 5a8287f37..e7a0d0e74 100644
--- a/docs/app-architecture.rst
+++ b/docs/app-architecture.rst
@@ -58,7 +58,7 @@ Tendermint Core RPC
 
 The concept is that the ABCI app is completely hidden from the outside
 world and only communicated through a tested and secured `interface
-exposed by the tendermint core <./rpc.html>`__. This interface
+exposed by the tendermint core <./specification/rpc.html>`__. This interface
 exposes a lot of data on the block header and consensus process, which
 is quite useful for externally verifying the system. It also includes
 3(!) methods to broadcast a transaction (propose it for the blockchain,
diff --git a/docs/architecture/ABCI.md b/docs/architecture/ABCI.md
deleted file mode 100644
index 04d62c1ce..000000000
--- a/docs/architecture/ABCI.md
+++ /dev/null
@@ -1,16 +0,0 @@
-# ABCI
-
-ABCI is an interface between the consensus/blockchain engine known as tendermint, and the application-specific business logic, known as an ABCi app.
-
-The tendermint core should run unchanged for all apps.  Each app can customize it, the supported transactions, queries, even the validator sets and how to handle staking / slashing stake. This customization is achieved by implementing the ABCi app to send the proper information to the tendermint engine to perform as directed.
-
-To understand this decision better, think of the design of the tendermint engine.
-
-* A blockchain is simply consensus on a unique global ordering of events.
-* This consensus can efficiently be implemented using BFT and PoS
-* This code can be generalized to easily support a large number of blockchains
-* The block-chain specific code, the interpretation of the individual events, can be implemented by a 3rd party app without touching the consensus engine core
-* Use an efficient, language-agnostic layer to implement this (ABCi)
-
-
-Bucky, please make this doc real.
diff --git a/docs/architecture/README.md b/docs/architecture/README.md
index dc9c62a9e..9e41d3064 100644
--- a/docs/architecture/README.md
+++ b/docs/architecture/README.md
@@ -2,15 +2,4 @@
 
 This is a location to record all high-level architecture decisions in the tendermint project.  Not the implementation details, but the reasoning that happened.  This should be refered to for guidance of the "right way" to extend the application.  And if we notice that the original decisions were lacking, we should have another open discussion, record the new decisions here, and then modify the code to match.
 
-This is like our guide and mentor when Jae and Bucky are offline.... The concept comes from a [blog post](https://product.reverb.com/documenting-architecture-decisions-the-reverb-way-a3563bb24bd0#.78xhdix6t) that resonated among the team when Anton shared it.
-
-Each section of the code can have it's own markdown file in this directory, and please add a link to the readme.
-
-## Sections
-
-* [ABCI](./ABCI.md)
-* [go-merkle / merkleeyes](./merkle.md)
-* [Frey's thoughts on the data store](./merkle-frey.md)
-* basecoin
-* tendermint core (multiple sections)
-* ???
+Read up on the concept in this [blog post](https://product.reverb.com/documenting-architecture-decisions-the-reverb-way-a3563bb24bd0#.78xhdix6t).
diff --git a/docs/architecture/adr-001.md b/docs/architecture/adr-001-logging.md
similarity index 100%
rename from docs/architecture/adr-001.md
rename to docs/architecture/adr-001-logging.md
diff --git a/docs/architecture/adr-002.md b/docs/architecture/adr-002-event-subscription.md
similarity index 98%
rename from docs/architecture/adr-002.md
rename to docs/architecture/adr-002-event-subscription.md
index 3c1f51b6e..cc207c4af 100644
--- a/docs/architecture/adr-002.md
+++ b/docs/architecture/adr-002-event-subscription.md
@@ -1,4 +1,4 @@
-# ADR 2: Indexing
+# ADR 2: Event Subscription
 
 ## Context
 
diff --git a/docs/architecture/adr-003.md b/docs/architecture/adr-003-abci-app-rpc.md
similarity index 95%
rename from docs/architecture/adr-003.md
rename to docs/architecture/adr-003-abci-app-rpc.md
index 7384a5d93..2775db077 100644
--- a/docs/architecture/adr-003.md
+++ b/docs/architecture/adr-003-abci-app-rpc.md
@@ -1,4 +1,4 @@
-# ADR 1: Must an ABCI-app have an RPC server?
+# ADR 3: Must an ABCI-app have an RPC server?
 
 ## Context
 
diff --git a/docs/architecture/adr-004-historical-validators.md b/docs/architecture/adr-004-historical-validators.md
new file mode 100644
index 000000000..be0de22c1
--- /dev/null
+++ b/docs/architecture/adr-004-historical-validators.md
@@ -0,0 +1,38 @@
+# ADR 004: Historical Validators
+
+## Context
+
+Right now, we can query the present validator set, but there is no history.
+If you were offline for a long time, there is no way to reconstruct past validators.  This is needed for the light client and we agreed needs enhancement of the API.
+
+## Decision
+
+For every block, store a new structure that contains either the latest validator set, 
+or the height of the last block for which the validator set changed. Note this is not
+the height of the block which returned the validator set change itself, but the next block,
+ie. the first block it comes into effect for.
+
+Storing the validators will be handled by the `state` package.
+
+At some point in the future, we may consider more efficient storage in the case where the validators
+are updated frequently - for instance by only saving the diffs, rather than the whole set.
+
+An alternative approach suggested keeping the validator set, or diffs of it, in a merkle IAVL tree.
+While it might afford cheaper proofs that a validator set has not changed, it would be more complex,
+and likely less efficient. 
+
+## Status
+
+Accepted.
+
+## Consequences
+
+### Positive
+
+- Can query old validator sets, with proof.
+
+### Negative
+
+- Writes an extra structure to disk with every block.
+
+### Neutral
diff --git a/docs/architecture/adr-005-consensus-params.md b/docs/architecture/adr-005-consensus-params.md
new file mode 100644
index 000000000..678de42eb
--- /dev/null
+++ b/docs/architecture/adr-005-consensus-params.md
@@ -0,0 +1,85 @@
+# ADR 005: Consensus Params
+
+## Context
+
+Consensus critical parameters controlling blockchain capacity have until now been hard coded, loaded from a local config, or neglected.
+Since they may be need to be different in different networks, and potentially to evolve over time within
+networks, we seek to initialize them in a genesis file, and expose them through the ABCI.
+
+While we have some specific parameters now, like maximum block and transaction size, we expect to have more in the future,
+such as a period over which evidence is valid, or the frequency of checkpoints. 
+
+## Decision
+
+### ConsensusParams
+
+No consensus critical parameters should ever be found in the `config.toml`.
+
+A new `ConsensusParams` is optionally included in the `genesis.json` file,
+and loaded into the `State`. Any items not included are set to their default value.
+A value of 0 is undefined (see ABCI, below). A value of -1 is used to indicate the parameter does not apply.
+The parameters are used to determine the validity of a block (and tx) via the union of all relevant parameters.
+
+```
+type ConsensusParams struct {
+    BlockSizeParams
+    TxSizeParams
+    BlockGossipParams
+}
+
+type BlockSizeParams struct {
+    MaxBytes int
+    MaxTxs int
+    MaxGas int
+}
+
+type TxSizeParams struct {
+    MaxBytes int
+    MaxGas int
+}
+
+type BlockGossipParams struct {
+    BlockPartSizeBytes int
+}
+```
+
+The `ConsensusParams` can evolve over time by adding new structs that cover different aspects of the consensus rules.
+
+The `BlockPartSizeBytes` and the `BlockSizeParams.MaxBytes` are enforced to be greater than 0. 
+The former because we need a part size, the latter so that we always have at least some sanity check over the size of blocks.
+
+### ABCI
+
+#### InitChain
+
+InitChain currently takes the initial validator set. It should be extended to also take parts of the ConsensusParams.
+There is some case to be made for it to take the entire Genesis, except there may be things in the genesis, 
+like the BlockPartSize, that the app shouldn't really know about.
+
+#### EndBlock
+
+The EndBlock response includes a `ConsensusParams`, which includes BlockSizeParams and TxSizeParams, but not BlockGossipParams.
+Other param struct can be added to `ConsensusParams` in the future.
+The `0` value is used to denote no change. 
+Any other value will update that parameter in the `State.ConsensusParams`, to be applied for the next block.
+Tendermint should have hard-coded upper limits as sanity checks.
+
+## Status
+
+Proposed.
+
+## Consequences
+
+### Positive
+
+- Alternative capacity limits and consensus parameters can be specified without re-compiling the software.
+- They can also change over time under the control of the application
+
+### Negative
+
+- More exposed parameters is more complexity
+- Different rules at different heights in the blockchain complicates fast sync
+
+### Neutral
+
+- The TxSizeParams, which checks validity, may be in conflict with the config's `max_block_size_tx`, which determines proposal sizes
diff --git a/docs/architecture/adr-template.md b/docs/architecture/adr-template.md
new file mode 100644
index 000000000..2303490ad
--- /dev/null
+++ b/docs/architecture/adr-template.md
@@ -0,0 +1,16 @@
+# ADR 000: Template for an ADR
+
+## Context
+
+## Decision
+
+## Status
+
+
+## Consequences
+
+### Positive
+
+### Negative
+
+### Neutral
diff --git a/docs/architecture/merkle-frey.md b/docs/architecture/merkle-frey.md
deleted file mode 100644
index aca4ce32e..000000000
--- a/docs/architecture/merkle-frey.md
+++ /dev/null
@@ -1,240 +0,0 @@
-# Merkle data stores - Frey's proposal
-
-## TL;DR
-
-To allow the efficient creation of an ABCi app, tendermint wishes to provide a reference implementation of a key-value store that provides merkle proofs of the data.  These proofs then quickly allow the ABCi app to provide an app hash to the consensus engine, as well as a full proof to any client.
-
-This is equivalent to building a database, and I would propose designing it from the API first, then looking how to implement this (or make an adapter from the API to existing implementations). Once we agree on the functionality and the interface, we can implement the API bindings, and then work on building adapters to existence merkle-ized data stores, or modifying the stores to support this interface.
-
-We need to consider the API (both in-process and over the network), language bindings, maintaining handles to old state (and garbage collecting), persistence, security, providing merkle proofs, and general key-value store operations. To stay consistent with the blockchains "single global order of operations", this data store should only allow one connection at a time to have write access.
-
-## Overview
-
-* **State**
-  * There are two concepts of state, "committed state" and "working state"
-  * The working state is only accessible from the ABCi app, allows writing, but does not need to support proofs.
-  * When we commit the "working state", it becomes a new "committed state" and has an immutable root hash, provides proofs, and can be exposed to external clients.
-* **Transactions**
-  * The database always allows creating a read-only transaction at the last "committed state", this transaction can serve read queries and proofs.
-  * The database maintains all data to serve these read transactions until they are closed by the client (or time out).  This allows the client(s) to determine how much old info is needed
-  * The database can only support *maximal* one writable transaction at a time.  This makes it easy to enforce serializability, and attempting to start a second writable transaction may trigger a panic.
-* **Functionality**
-  * It must support efficient key-value operations (get/set/delete)
-  * It must support returning merkle proofs for any "committed state"
-  * It should support range queries on subsets of the key space if possible (ie. if the db doesn't hash keys)
-  * It should also support listening to changes to a desired key via pub-sub or similar method, so I can quickly notify you on a change to your balance without constant polling.
-  * It may support other db-specific query types as an extension to this interface, as long as all specified actions maintain their meaning.
-* **Interface**
-  * This interface should be domain-specific - ie. designed just for this use case
-  * It should present a simple go interface for embedding the data store in-process
-  * It should create a gRPC/protobuf API for calling from any client
-  * It should provide and maintain client adapters from our in-process interface to gRPC client calls for at least golang and Java (maybe more languages?)
-  * It should provide and maintain server adapters from our gRPC calls to the in-process interface for golang at least (unless there is another server we wish to support)
-* **Persistence**
-  * It must support atomic persistence upon committing a new block.  That is, upon crash recovery, the state is guaranteed to represent the state at the end of a complete block (along with a note of which height it was).
-  * It must delay deletion of old data as long as there are open read-only transactions referring to it, thus we must maintain some sort of WAL to keep track of pending cleanup.
-  * When a transaction is closed, or when we recover from a crash, it should clean up all no longer needed data to avoid memory/storage leaks.
-* **Security and Auth**
-  * If we allow connections over gRPC, we must consider this issues and allow both encryption (SSL), and some basic auth rules to prevent undesired access to the DB
-  * This is client-specific and does not need to be supported in the in-process, embedded version.
-
-## Details
-
-Here we go more in-depth in each of the sections, explaining the reasoning and more details on the desired behavior. This document is only the high-level architecture and should support multiple implementations.  When building out a specific implementation, a similar document should be provided for that repo, showing how it implements these concepts, and details about memory usage, storage, efficiency, etc.
-
-
-### State
-
-The current ABCi interface avoids this question a bit and that has brought confusion.  If I use `merkleeyes` to store data, which state is returned from `Query`?  The current "working" state, which I would like to refer to in my ABCi application?  Or the last committed state, which I would like to return to a client's query?  Or an old state, which I may select based on height?
-
-Right now, `merkleeyes` implements `Query` like a normal ABCi app and only returns committed state, which has lead to problems and confusion.  Thus, we need to be explicit about which state we want to view.  Each viewer can then specify which state it wants to view.  This allows the app to query the working state in DeliverTx, but the committed state in Query.
-
-We can easily provide two global references for "last committed" and "current working" states.  However, if we want to also allow querying of older commits... then we need some way to keep track of which ones are still in use, so we can garbage collect the unneeded ones. There is a non-trivial overhead in holding references to all past states, but also a hard-coded solution (hold onto the last 5 commits) may not support all clients.  We should let the client define this somehow.
-
-### Transactions
-
-Transactions (in the typical database sense) are a clean and established solution to this issue.  We can look at the [isolations levels](https://en.wikipedia.org/wiki/Isolation_(database_systems)#Serializable) which attempt to provide us things like "repeatable reads".  That means if we open a transaction, and query some data 100 times while other processes are writing to the db, we get the same result each time.  This transaction has a reference to its own local state from the time the transaction started. (We are referring to the highest isolation levels here, which correlate well this the blockchain use case).
-
-If we implement a read-only transaction as a reference to state at the time of creation of that transaction, we can then hold these references to various snapshots, one per block that we are interested, and allow the client to multiplex queries and proofs from these various blocks.
-
-If we continue using these concepts (which have informed 30+ years of server side design), we can add a few nice features to our write transactions. The first of which is `Rollback` and `Commit`.  That means all the changes we make in this transaction have no effect on the database until they are committed.  And until they are committed, we can always abort if we detect an anomaly, returning to the last committed state with a rollback.
-
-There is also a nice extension to this available on some database servers, basically, "nested" transactions or "savepoints".  This means that within one transaction, you can open a subtransaction/savepoint and continue work.  Later you have the option to commit or rollback all work since the savepoint/subtransaction.  And then continue with the main transaction.
-
-If you don't understand why this is useful, look at how basecoin needs to [hold cached state for AppTx](https://github.com/tendermint/basecoin/blob/master/state/execution.go#L126-L149), meaning that it rolls back all modifications if the AppTx returns an error. This was implemented as a wrapper in basecoin, but it is a reasonable thing to support in the DB interface itself (especially since the implementation becomes quite non-trivial as soon as you support range queries).
-
-To give a bit more reference to this concept in practice, read about [Savepoints in Postgresql](https://www.postgresql.org/docs/current/static/tutorial-transactions.html) ([reference](https://www.postgresql.org/docs/current/static/sql-savepoint.html)) or [Nesting transactions in SQL Server](http://dba-presents.com/index.php/databases/sql-server/43-nesting-transactions-and-save-transaction-command) (TL;DR: scroll to the bottom, section "Real nesting transactions with SAVE TRANSACTION")
-
-### Functionality
-
-Merkle trees work with key-value pairs, so we should most importantly focus on the basic Key-Value operations.  That is `Get`, `Set`, and `Remove`. We also need to return a merkle proof for any key, along with a root hash of the tree for committing state to the blockchain. This is just the basic merkle-tree stuff.
-
-If it is possible with the implementation, it is nice to provide access to Range Queries.  That is, return all values where the key is between X and Y.  If you construct your keys wisely, it is possible to store lists (1:N) relations this way.  Eg, storing blog posts and the key is blog:`poster_id`:`sequence`, then I could search for all blog posts by a given `poster_id`, or even return just posts 10-19 from the given poster.
-
-The construction of a tree that supports range queries was one of the [design decisions of go-merkle](https://github.com/tendermint/go-merkle/blob/master/README.md).  It is also kind of possible with [ethereum's patricia trie](https://github.com/ethereum/wiki/wiki/Patricia-Tree) as long as the key is less than 32 bytes.
-
-In addition to range queries, there is one more nice feature that we could add to our data store - listening to events. Depending on your context, this is "reactive programming", "event emitters", "notifications", etc... But the basic concept is that a client can listen for all changes to a given key (or set of keys), and receive a notification when this happens. This is very important to avoid [repeated polling and wasted queries](http://resthooks.org/) when a client simply wants to [detect changes](https://www.rethinkdb.com/blog/realtime-web/).
-
-If the database provides access to some "listener" functionality, the app can choose to expose this to the external client via websockets, web hooks, http2 push events, android push notifications, etc, etc etc.... But if we want to support modern client functionality, let's add support for this reactive paradigm in our DB interface.
-
-**TODO** support for more advanced backends, eg. Bolt....
-
-### Go Interface
-
-I will start with a simple go interface to illustrate the in-process interface.  Once there is agreement on how this looks, we can work out the gRPC bindings to support calling out of process. These interfaces are not finalized code, but I think the demonstrate the concepts better than text and provide a strawman to get feedback.
-
-```
-// DB represents the committed state of a merkle-ized key-value store
-type DB interface {
-  // Snapshot returns a reference to last committed state to use for
-  // providing proofs, you must close it at the end to garbage collect
-  // the historical state we hold on to to make these proofs
-  Snapshot() Prover
-
-  // Start a transaction - only way to change state
-  // This will return an error if there is an open Transaction
-  Begin() (Transaction, error)
-
-  // These callbacks are triggered when the Transaction is Committed
-  // to the DB.  They can be used to eg. notify clients via websockets when
-  // their account balance changes.
-  AddListener(key []byte, listener Listener)
-  RemoveListener(listener Listener)
-}
-
-// DBReader represents a read-only connection to a snapshot of the db
-type DBReader interface {
-  // Queries on my local view
-  Has(key []byte) (bool, error)
-  Get(key []byte) (Model, error)
-  GetRange(start, end []byte, ascending bool, limit int) ([]Model, error)
-  Closer
-}
-
-// Prover is an interface that lets one query for Proofs, holding the
-// data at a specific location in memory
-type Prover interface {
-  DBReader
-
-  // Hash is the AppHash (RootHash) for this block
-  Hash() (hash []byte)
-
-  // Prove returns the data along with a merkle Proof
-  // Model and Proof are nil if not found
-  Prove(key []byte) (Model, Proof, error)
-}
-
-// Transaction is a set of state changes to the DB to be applied atomically.
-// There can only be one open transaction at a time, which may only have
-// maximum one subtransaction at a time.
-// In short, at any time, there is exactly one object that can write to the
-// DB, and we can use Subtransactions to group operations and roll them back
-// together (kind of like `types.KVCache` from basecoin)
-type Transaction interface {
-  DBReader
-
-  // Change the state - will raise error immediately if this Transaction
-  // is not holding the exclusive write lock
-  Set(model Model) (err error)
-  Remove(key []byte) (removed bool, err error)
-
-  // Subtransaction starts a new subtransaction, rollback will not affect the
-  // parent.  Only on Commit are the changes applied to this transaction.
-  // While the subtransaction exists, no write allowed on the parent.
-  // (You must Commit or Rollback the child to continue)
-  Subtransaction() Transaction
-
-  // Commit this transaction (or subtransaction), the parent reference is
-  // now updated.
-  // This only updates persistant store if the top level transaction commits
-  // (You may have any number of nested sub transactions)
-  Commit() error
-
-  // Rollback ends the transaction and throw away all transaction-local state,
-  // allowing the tree to prune those elements.
-  // The parent transaction now recovers the write lock.
-  Rollback()
-}
-
-// Listener registers callbacks on changes to the data store
-type Listener interface {
-  OnSet(key, value, oldValue []byte)
-  OnRemove(key, oldValue []byte)
-}
-
-// Proof represents a merkle proof for a key
-type Proof interface {
-  RootHash() []byte
-  Verify(key, value, root []byte) bool
-}
-
-type Model interface {
-  Key() []byte
-  Value() []byte
-}
-
-// Closer releases the reference to this state, allowing us to garbage collect
-// Make sure to call it before discarding.
-type Closer interface {
-  Close()
-}
-```
-
-### Remote Interface
-
-The use-case of allowing out-of-process calls is very powerful.  Not just to provide a powerful merkle-ready data store to non-go applications.
-
-It we allow the ABCi app to maintain the only writable connections, we can guarantee that all transactions are only processed through the tendermint consensus engine.  We could then allow multiple "web server" machines "read-only" access and scale out the database reads, assuming the consensus engine, ABCi logic, and public key cryptography is more the bottleneck than the database. We could even place the consensus engine, ABCi app, and data store on one machine, connected with unix sockets for security, and expose a tcp/ssl interface for reading the data, to scale out query processing over multiple machines.
-
-But returning our focus directly to the ABCi app (which is the most important use case).  An app may well want to maintain 100 or 1000 snapshots of different heights to allow people to easily query many proofs at a given height without race conditions (very important for IBC, ask Jae).  Thus, we should not require a separate TCP connection for each height, as this gets quite awkward with so many connections. Also, if we want to use gRPC, we should consider the connections potentially transient (although they are more efficient with keep-alive).
-
-Thus, the wire encoding of a transaction or a snapshot should simply return a unique id.  All methods on a `Prover` or `Transaction` over the wire can send this id along with the arguments for the method call.  And we just need a hash map on the server to map this id to a state.
-
-The only negative of not requiring a persistent tcp connection for each snapshot is there is no auto-detection if the client crashes without explicitly closing the connections.  Thus, I would suggest adding a `Ping` thread in the gRPC interface which keeps the Snapshot alive.  If no ping is received within a server-defined time, it may automatically close those transactions.  And if we consider a client with 500 snapshots that needs to ping each every 10 seconds, that is a lot of overhead, so we should design the ping to accept a list of IDs for the client and update them all.  Or associate all snapshots with a clientID and then just send the clientID in the ping.  (Please add other ideas on how to detect client crashes without persistent connections).
-
-To encourage adoption, we should provide a nice client that uses this gRPC interface (like we do with ABCi).  For go, the client may have the exact same interface as the in-process version, just that the error call may return network errors, not just illegal operations.  We should also add a client with a clean API for Java, since that seems to be popular among app developers in the current tendermint community.  Other bindings as we see the need in the server space.
-
-### Persistence
-
-Any data store worth it's name should not lose all data on a crash.  Even [redis provides some persistence](https://redis.io/topics/persistence) these days. Ideally, if the system crashes and restarts, it should have the data at the last block N that was committed.  If the system crash during the commit of block N+1, then the recovered state should either be block N or completely committed block N+1, but no partial state between the two.  Basically, the commit must be an atomic operation (even if updating 100's of records).
-
-To avoid a lot of headaches ourselves, we can use an existing data store, such as leveldb, which provides `WriteBatch` to group all operations.
-
-The other issue is cleaning up old state.  We cannot delete any information from our persistent store, as long as any snapshot holds a reference to it (or else we get some panics when the data we query is not there).  So, we need to store the outstanding deletions that we can perform when the snapshot is `Close`d.  In addition, we must consider the case that the data store crashes with open snapshots.  Thus, the info on outstanding deletions must also be persisted somewhere.  Something like a "delete-behind log" (the opposite of a "write ahead log").
-
-This is not a concern of the generic interface, but each implementation should take care to handle this well to avoid accumulation of unused references in the data store and eventual data bloat.
-
-#### Backing stores
-
-It is way outside the scope of this project to build our own database that is capable of efficiently storing the data, provide multiple read-only snapshots at once, and save it atomically. The best approach seems to select an existing database (best a simple one) that provides this functionality and build upon it, much like the current `go-merkle` implementation builds upon `leveldb`.  After some research here are winners and losers:
-
-**Winners**
-
-* Leveldb - [provides consistent snapshots](https://ayende.com/blog/161705/reviewing-leveldb-part-xiii-smile-and-here-is-your-snapshot), and [provides tooling for building ACID compliance](http://codeofrob.com/entries/writing-a-transaction-manager-on-top-of-leveldb.html)
-  * Note there are at least two solid implementations available in go - [goleveldb](https://github.com/syndtr/goleveldb) - a pure go implementation, and [levigo](https://github.com/jmhodges/levigo) - a go wrapper around leveldb.
-  * Goleveldb is much easier to compile and cross-compile (not requiring cgo), while levigo (or cleveldb) seems to provide a significant performance boosts (but I had trouble even running benchmarks)
-* PostgreSQL - fully supports these ACID semantics if you call `SET TRANSACTION ISOLATION LEVEL SERIALIZABLE` at the beginning of a transaction (tested)
-  * This may be total overkill unless we also want to make use of other features, like storing data in multiple columns with secondary indexes.
-  * Trillian can show an example of [how to store a merkle tree in sql](https://github.com/google/trillian/blob/master/storage/mysql/tree_storage.go)
-
-**Losers**
-
-* Bolt - open [read-only snapshots can block writing](https://github.com/boltdb/bolt/issues/378)
-* Mongo - [barely even supports atomic operations](https://docs.mongodb.com/manual/core/write-operations-atomicity/), much less multiple snapshots
-
-**To investigate**
-
-* [Trillian](https://github.com/google/trillian) - has a [persistent merkle tree interface](https://github.com/google/trillian/blob/master/storage/tree_storage.go) along with [backend storage with mysql](https://github.com/google/trillian/blob/master/storage/mysql/tree_storage.go), good inspiration for our design if not directly using it
-* [Moss](https://github.com/couchbase/moss) - another key-value store in go, seems similar to leveldb, maybe compare with performance tests?
-
-### Security
-
-When allowing access out-of-process, we should provide different mechanisms to secure it.  The first is the choice of binding to a local unix socket or a tcp port.  The second is the optional use of ssl to encrypt the connection (very important over tcp).  The third is authentication to control access to the database.
-
-We may also want to consider the case of two server connections with different permissions, eg. a local unix socket that allows write access with no more credentials, and a public TCP connection with ssl and authentication that only provides read-only access.
-
-The use of ssl is quite easy in go, we just need to generate and sign a certificate, so it is nice to be able to disable it for dev machines, but it is very important for production.
-
-For authentication, let me sketch out a minimal solution. The server could just have a simple config file with key/bcrypt(password) pairs along with read/write permission level, and read that upon startup.  The client must provide a username and password in the HTTP headers when making the original HTTPS gRPC connection.
-
-This is super minimal to provide some protection. Things like LDAP, OAuth and single-sign on seem overkill and even potential security holes.  Maybe there is another solution somewhere in the middle.
diff --git a/docs/architecture/merkle.md b/docs/architecture/merkle.md
deleted file mode 100644
index 4e769aed6..000000000
--- a/docs/architecture/merkle.md
+++ /dev/null
@@ -1,17 +0,0 @@
-# Merkle data stores
-
-To allow the efficient creation of an ABCi app, tendermint wishes to provide a reference implemention of a key-value store that provides merkle proofs of the data.  These proofs then quickly allow the ABCi app to provide an apphash to the consensus engine, as well as a full proof to any client.
-
-This engine is currently implemented in `go-merkle` with `merkleeyes` providing a language-agnostic binding via ABCi.  It uses `tmlibs/db` bindings internally to persist data to leveldb.
-
-What are some of the requirements of this store:
-
-* It must support efficient key-value operations (get/set/delete)
-* It must support persistance.
-* We must only persist complete blocks, so when we come up after a crash we are at the state of block N or N+1, but not in-between these two states.
-* It must allow us to read/write from one uncommited state (working state), while serving other queries from the last commited state. And a way to determine which one to serve for each client.
-* It must allow us to hold references to old state, to allow providing proofs from 20 blocks ago.  We can define some limits as to the maximum time to hold this data.
-* We provide in process binding in Go
-* We provide language-agnostic bindings when running the data store as it's own process.
-
-
diff --git a/docs/images/abci.png b/docs/assets/abci.png
similarity index 100%
rename from docs/images/abci.png
rename to docs/assets/abci.png
diff --git a/docs/images/consensus_logic.png b/docs/assets/consensus_logic.png
similarity index 100%
rename from docs/images/consensus_logic.png
rename to docs/assets/consensus_logic.png
diff --git a/docs/images/tm-transaction-flow.png b/docs/assets/tm-transaction-flow.png
similarity index 100%
rename from docs/images/tm-transaction-flow.png
rename to docs/assets/tm-transaction-flow.png
diff --git a/docs/conf.py b/docs/conf.py
index 25a6bbf87..d5c49355f 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -16,9 +16,10 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 #
-# import os
+import os
 # import sys
 # sys.path.insert(0, os.path.abspath('.'))
+import urllib
 
 import sphinx_rtd_theme
 
@@ -169,3 +170,30 @@ texinfo_documents = [
      author, 'Tendermint', 'Byzantine Fault Tolerant Consensus.',
      'Database'),
 ]
+
+repo = "https://raw.githubusercontent.com/tendermint/tools/"
+branch = "master"
+
+tools = "./tools"
+assets = tools + "/assets"
+
+if os.path.isdir(tools) != True:
+    os.mkdir(tools)
+if os.path.isdir(assets) != True:
+    os.mkdir(assets)
+
+urllib.urlretrieve(repo+branch+'/ansible/README.rst', filename=tools+'/ansible.rst')
+urllib.urlretrieve(repo+branch+'/ansible/assets/a_plus_t.png', filename=assets+'/a_plus_t.png')
+
+urllib.urlretrieve(repo+branch+'/docker/README.rst', filename=tools+'/docker.rst')
+
+urllib.urlretrieve(repo+branch+'/mintnet-kubernetes/README.rst', filename=tools+'/mintnet-kubernetes.rst')
+urllib.urlretrieve(repo+branch+'/mintnet-kubernetes/assets/gce1.png', filename=assets+'/gce1.png')
+urllib.urlretrieve(repo+branch+'/mintnet-kubernetes/assets/gce2.png', filename=assets+'/gce2.png')
+urllib.urlretrieve(repo+branch+'/mintnet-kubernetes/assets/statefulset.png', filename=assets+'/statefulset.png')
+urllib.urlretrieve(repo+branch+'/mintnet-kubernetes/assets/t_plus_k.png', filename=assets+'/t_plus_k.png')
+
+urllib.urlretrieve(repo+branch+'/terraform-digitalocean/README.rst', filename=tools+'/terraform-digitalocean.rst')
+urllib.urlretrieve(repo+branch+'/tm-bench/README.rst', filename=tools+'/benchmarking-and-monitoring.rst')
+# the readme for below is included in tm-bench
+# urllib.urlretrieve('https://raw.githubusercontent.com/tendermint/tools/master/tm-monitor/README.rst', filename='tools/tm-monitor.rst')
diff --git a/docs/deploy-testnets.rst b/docs/deploy-testnets.rst
index 66cee8cd4..e1aa7074d 100644
--- a/docs/deploy-testnets.rst
+++ b/docs/deploy-testnets.rst
@@ -40,8 +40,51 @@ Automated Deployments
 ---------------------
 
 While the manual deployment is easy enough, an automated deployment is
-always better. For this, we have the `mintnet-kubernetes
-tool <https://github.com/tendermint/tools/tree/master/mintnet-kubernetes>`__,
-which allows us to automate the deployment of a Tendermint network on an
-already provisioned kubernetes cluster. And for simple provisioning of kubernetes
+usually quicker. The below examples show different tools that can be used
+for automated deployments.
+
+Automated Deployment using Kubernetes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The `mintnet-kubernetes tool <https://github.com/tendermint/tools/tree/master/mintnet-kubernetes>`__
+allows automating the deployment of a Tendermint network on an already
+provisioned kubernetes cluster. For simple provisioning of a kubernetes
 cluster, check out the `Google Cloud Platform <https://cloud.google.com/>`__.
+
+Automated Deployment using Terraform and Ansible
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The `terraform-digitalocean tool <https://github.com/tendermint/tools/tree/master/terraform-digitalocean>`__
+allows creating a set of servers on the DigitalOcean cloud.
+
+The `ansible playbooks <https://github.com/tendermint/tools/tree/master/ansible>`__
+allow creating and managing a ``basecoin`` or ``ethermint`` testnet on provisioned servers.
+
+Package Deployment on Linux for developers
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``tendermint`` and ``basecoin`` applications can be installed from RPM or DEB packages on
+Linux machines for development purposes. The packages are configured to be validators on the
+one-node network that the machine represents. The services are not started after installation,
+this way giving an opportunity to reconfigure the applications before starting.
+
+The Ansible playbooks in the previous section use this repository to install ``basecoin``.
+After installation, additional steps are executed to make sure that the multi-node testnet has
+the right configuration before start.
+
+Install from the CentOS/RedHat repository:
+
+::
+
+    rpm --import https://tendermint-packages.interblock.io/centos/7/os/x86_64/RPM-GPG-KEY-Tendermint
+    wget -O /etc/yum.repos.d/tendermint.repo https://tendermint-packages.interblock.io/centos/7/os/x86_64/tendermint.repo
+    yum install basecoin
+
+Install from the Debian/Ubuntu repository:
+
+::
+
+    wget -O - https://tendermint-packages.interblock.io/centos/7/os/x86_64/RPM-GPG-KEY-Tendermint | apt-key add -
+    wget -O /etc/apt/sources.list.d/tendermint.list https://tendermint-packages.interblock.io/debian/tendermint.list
+    apt-get update && apt-get install basecoin
+
diff --git a/docs/ecosystem.rst b/docs/ecosystem.rst
new file mode 100644
index 000000000..188f50092
--- /dev/null
+++ b/docs/ecosystem.rst
@@ -0,0 +1,94 @@
+Tendermint Ecosystem
+====================
+
+Below are the many applications built using various pieces of the Tendermint stack. We thank the community for their contributions thus far  and welcome the addition of new projects. Feel free to submit a pull request to add your project!
+
+ABCI Applications
+-----------------
+
+Burrow
+^^^^^^
+
+Ethereum Virtual Machine augmented with native permissioning scheme and global key-value store, written in Go, authored by Monax Industries, and incubated `by Hyperledger <https://github.com/hyperledger/burrow>`__.
+
+cb-ledger
+^^^^^^^^^
+
+Custodian Bank Ledger, integrating central banking with the blockchains of tomorrow, written in C++, and `authored by Block Finance <https://github.com/block-finance/cpp-abci>`__.
+      
+Clearchain
+^^^^^^^^^^
+
+Application to manage a distributed ledger for money transfers that support multi-currency accounts, written in Go, and `authored by Allession Treglia <https://github.com/tendermint/clearchain>`__.
+
+Comit
+^^^^^
+
+Public service reporting and tracking, written in Go, and `authored by Zach Balder <https://github.com/zbo14/comit>`__.
+     
+Cosmos SDK
+^^^^^^^^^^
+
+A prototypical account based crypto currency state machine supporting plugins, written in Go, and `authored by Cosmos <https://github.com/cosmos/cosmos-sdk>`__.
+
+Ethermint
+^^^^^^^^^
+
+The go-ethereum state machine run as a ABCI app, written in Go, `authored by Tendermint <https://github.com/tendermint/ethermint>`__.
+
+
+Merkle AVL Tree
+^^^^^^^^^^^^^^^
+
+The following are implementations of the Tendermint IAVL tree as an ABCI application
+
+Merkleeyes
+~~~~~~~~~~
+
+Written in Go, `authored by Tendermint <https://github.com/tendermint/merkleeyes>`__.
+
+MerkleTree
+~~~~~~~~~~
+
+Written in Java, `authored by jTendermint <https://github.com/jTendermint/MerkleTree>`__.
+
+
+TMChat
+^^^^^^
+
+P2P chat using Tendermint, written in Java, `authored by woldposd <https://github.com/wolfposd/TMChat>`__.
+      
+Passwerk
+^^^^^^^^
+
+Encrypted storage web-utility backed by Tendermint, written in Go, `authored by Rigel Rozanski <https://github.com/rigelrozanski/passwerk>`__.
+
+ABCI Servers
+------------
+
+
++-------------------------------------------------------------+--------------------+--------------+
+| **Name**                                                    | **Author**         | **Language** |       
+|                                                             |                    |              |      
++-------------------------------------------------------------+--------------------+--------------+
+| `abci <https://github.com/tendermint/abci>`__               | Tendermint         | Go           |
++-------------------------------------------------------------+--------------------+--------------+
+| `js abci <https://github.com/tendermint/js-abci>`__         | Tendermint         | Javascript   |                       
++-------------------------------------------------------------+--------------------+--------------+
+| `cpp-tmsp <https://github.com/mdyring/cpp-tmsp>`__          | Martin Dyring      | C++          |
++-------------------------------------------------------------+--------------------+--------------+
+| `jabci <https://github.com/jTendermint/jabci>`__            | jTendermint        | Java         |
++-------------------------------------------------------------+--------------------+--------------+
+| `Spearmint <https://github.com/dennismckinnon/spearmint>`__ | Dennis Mckinnon    | Javascript   |
++-------------------------------------------------------------+--------------------+--------------+
+| `ocaml-tmsp <https://github.com/zbo14/ocaml-tmsp>`__        | Zach Balder        | Ocaml        |
++-------------------------------------------------------------+--------------------+--------------+
+| `abci_server <https://github.com/KrzysiekJ/abci_server>`__  | Krzysztof Jurewicz | Erlang       |
++-------------------------------------------------------------+--------------------+--------------+
+
+Deployment Tools
+----------------
+
+See `deploy testnets <./deploy-testnets.html>`__ for information about all the tools built by Tendermint. We have Kubernetes, Ansible, and Terraform integrations.
+
+Cloudsoft built `brooklyn-tendermint <https://github.com/cloudsoft/brooklyn-tendermint>`__ for deploying a tendermint testnet in docker continers. It uses Clocker for Apache Brooklyn.
diff --git a/docs/index.rst b/docs/index.rst
index 3d278f60c..ee1307bf2 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -23,9 +23,30 @@ Tendermint 101
    introduction.rst
    install.rst
    getting-started.rst
-   deploy-testnets.rst
    using-tendermint.rst
 
+Tendermint Tools
+----------------
+
+.. toctree::
+   :maxdepth: 2
+
+   deploy-testnets.rst
+   tools/ansible.rst
+   tools/docker.rst
+   tools/mintnet-kubernetes.rst
+   tools/terraform-digitalocean.rst
+   tools/benchmarking-and-monitoring.rst
+
+
+Tendermint Ecosystem
+--------------------
+
+.. toctree::
+   :maxdepth: 2
+
+   ecosystem.rst
+
 Tendermint 102
 --------------
 
diff --git a/docs/install.rst b/docs/install.rst
index b353aba87..1746daa9d 100644
--- a/docs/install.rst
+++ b/docs/install.rst
@@ -1,17 +1,24 @@
-Install from Source
-===================
+Install Tendermint
+==================
+
+From Binary
+-----------
+
+To download pre-built binaries, see the `Download page <https://tendermint.com/download>`__.
 
-This page provides instructions on installing Tendermint from source. To
-download pre-built binaries, see the `Download page <https://tendermint.com/download>`__.
+From Source
+-----------
+
+You'll need `go`, maybe `glide` and the tendermint source code.
 
 Install Go
-----------
+^^^^^^^^^^
 
 Make sure you have `installed Go <https://golang.org/doc/install>`__ and
 set the ``GOPATH``.
 
-Install Tendermint
-------------------
+Get Source Code
+^^^^^^^^^^^^^^^
 
 You should be able to install the latest with a simple
 
@@ -19,13 +26,14 @@ You should be able to install the latest with a simple
 
     go get github.com/tendermint/tendermint/cmd/tendermint
 
-Run ``tendermint --help`` for more.
+Run ``tendermint --help`` and ``tendermint version`` to ensure your
+installation worked.
 
 If the installation failed, a dependency may been updated and become
 incompatible with the latest Tendermint master branch. We solve this
 using the ``glide`` tool for dependency management.
 
-Fist, install ``glide``:
+First, install ``glide``:
 
 ::
 
@@ -45,7 +53,7 @@ still cloned to the correct location in the ``$GOPATH``.
 The latest Tendermint Core version is now installed.
 
 Reinstall
-~~~~~~~~~
+---------
 
 If you already have Tendermint installed, and you make updates, simply
 
@@ -79,7 +87,7 @@ Since the third option just uses ``glide`` right away, it should always
 work.
 
 Troubleshooting
-~~~~~~~~~~~~~~~
+---------------
 
 If ``go get`` failing bothers you, fetch the code using ``git``:
 
@@ -92,7 +100,7 @@ If ``go get`` failing bothers you, fetch the code using ``git``:
     go install ./cmd/tendermint
 
 Run
-~~~
+^^^
 
 To start a one-node blockchain with a simple in-process application:
 
diff --git a/docs/introduction.rst b/docs/introduction.rst
index cc56b1bdc..e37637ee7 100644
--- a/docs/introduction.rst
+++ b/docs/introduction.rst
@@ -86,10 +86,10 @@ And we plan to do the same for Bitcoin, ZCash, and various other deterministic a
 
 Another example of a cryptocurrency application built on Tendermint is `the Cosmos network <http://cosmos.network>`__.
 
-Fabric, Burrow
-~~~~~~~~~~~~~~
+Other Blockchain Projects
+~~~~~~~~~~~~~~~~~~~~~~~~~
 
-`Fabric <https://github.com/hyperledger/fabric>`__, takes a similar approach to Tendermint, but is more opinionated about how the state is managed,
+`Fabric <https://github.com/hyperledger/fabric>`__ takes a similar approach to Tendermint, but is more opinionated about how the state is managed,
 and requires that all application behaviour runs in potentially many docker containers, modules it calls "chaincode". 
 It uses an implementation of `PBFT <http://pmg.csail.mit.edu/papers/osdi99.pdf>`__.
 from a team at IBM that is 
@@ -156,7 +156,7 @@ There can be multiple ABCI socket connections to an application. Tendermint Core
 
 It's probably evident that applications designers need to very carefully design their message handlers to create a blockchain that does anything useful but this architecture provides a place to start. The diagram below illustrates the flow of messages via ABCI.
 
-.. figure:: images/abci.png
+.. figure:: assets/abci.png
 
 A Note on Determinism
 ~~~~~~~~~~~~~~~~~~~~~
@@ -180,7 +180,7 @@ Consensus Overview
 Tendermint is an easy-to-understand, mostly asynchronous, BFT consensus protocol.
 The protocol follows a simple state machine that looks like this:
 
-.. figure:: images/consensus_logic.png
+.. figure:: assets/consensus_logic.png
 
 Participants in the protocol are called "validators";
 they take turns proposing blocks of transactions and voting on them.
@@ -228,4 +228,4 @@ The `Cosmos Network <http://cosmos.network>`__ is designed to use this Proof-of-
 
 The following diagram is Tendermint in a (technical) nutshell. `See here for high resolution version <https://github.com/mobfoundry/hackatom/blob/master/tminfo.pdf>`__.
 
-.. figure:: images/tm-transaction-flow.png
+.. figure:: assets/tm-transaction-flow.png
diff --git a/docs/specification.rst b/docs/specification.rst
index 02d84c343..2e8b35668 100644
--- a/docs/specification.rst
+++ b/docs/specification.rst
@@ -7,14 +7,14 @@ Here you'll find details of the Tendermint specification. See `the spec repo <ht
 .. toctree::
    :maxdepth: 2
 
-   block-structure.rst
-   byzantine-consensus-algorithm.rst
-   configuration.rst
-   fast-sync.rst
-   genesis.rst
-   light-client-protocol.rst
-   merkle.rst
-   rpc.rst
-   secure-p2p.rst
-   validators.rst
-   wire-protocol.rst
+  specification/block-structure.rst
+  specification/byzantine-consensus-algorithm.rst
+  specification/configuration.rst
+  specification/fast-sync.rst
+  specification/genesis.rst
+  specification/light-client-protocol.rst
+  specification/merkle.rst
+  specification/rpc.rst
+  specification/secure-p2p.rst
+  specification/validators.rst
+  specification/wire-protocol.rst
diff --git a/docs/block-structure.rst b/docs/specification/block-structure.rst
similarity index 100%
rename from docs/block-structure.rst
rename to docs/specification/block-structure.rst
diff --git a/docs/byzantine-consensus-algorithm.rst b/docs/specification/byzantine-consensus-algorithm.rst
similarity index 100%
rename from docs/byzantine-consensus-algorithm.rst
rename to docs/specification/byzantine-consensus-algorithm.rst
diff --git a/docs/configuration.rst b/docs/specification/configuration.rst
similarity index 100%
rename from docs/configuration.rst
rename to docs/specification/configuration.rst
diff --git a/docs/fast-sync.rst b/docs/specification/fast-sync.rst
similarity index 100%
rename from docs/fast-sync.rst
rename to docs/specification/fast-sync.rst
diff --git a/docs/genesis.rst b/docs/specification/genesis.rst
similarity index 93%
rename from docs/genesis.rst
rename to docs/specification/genesis.rst
index 32dd19632..2187eb572 100644
--- a/docs/genesis.rst
+++ b/docs/specification/genesis.rst
@@ -21,7 +21,7 @@ Fields
 -  ``validators``:
 -  ``pub_key``: The first element specifies the pub\_key type. 1 ==
    Ed25519. The second element are the pubkey bytes.
--  ``amount``: The validator's voting power.
+-  ``power``: The validator's voting power.
 -  ``name``: Name of the validator (optional).
 -  ``app_hash``: The expected application hash (as returned by the
    ``Commit`` ABCI message) upon genesis. If the app's hash does not
@@ -41,7 +41,7 @@ Sample genesis.json
             1,
             "9BC5112CB9614D91CE423FA8744885126CD9D08D9FC9D1F42E552D662BAA411E"
           ],
-          "amount": 1,
+          "power": 1,
           "name": "mach1"
         },
         {
@@ -49,7 +49,7 @@ Sample genesis.json
             1,
             "F46A5543D51F31660D9F59653B4F96061A740FF7433E0DC1ECBC30BE8494DE06"
           ],
-          "amount": 1,
+          "power": 1,
           "name": "mach2"
         },
         {
@@ -57,7 +57,7 @@ Sample genesis.json
             1,
             "0E7B423C1635FD07C0FC3603B736D5D27953C1C6CA865BB9392CD79DE1A682BB"
           ],
-          "amount": 1,
+          "power": 1,
           "name": "mach3"
         },
         {
@@ -65,7 +65,7 @@ Sample genesis.json
             1,
             "4F49237B9A32EB50682EDD83C48CE9CDB1D02A7CFDADCFF6EC8C1FAADB358879"
           ],
-          "amount": 1,
+          "power": 1,
           "name": "mach4"
         }
       ],
diff --git a/docs/light-client-protocol.rst b/docs/specification/light-client-protocol.rst
similarity index 97%
rename from docs/light-client-protocol.rst
rename to docs/specification/light-client-protocol.rst
index e2d5ea76a..6c2531d71 100644
--- a/docs/light-client-protocol.rst
+++ b/docs/specification/light-client-protocol.rst
@@ -16,7 +16,7 @@ The objective of the light client protocol is to get a
 `block hash <./block-structure.html#block-hash>`__ where the commit
 includes a majority of signatures from the last known validator set.
 From there, all the application state is verifiable with `merkle
-proofs <./merkle-trees#iavl-tree>`__.
+proofs <./merkle.html#iavl-tree>`__.
 
 Properties
 ----------
diff --git a/docs/merkle.rst b/docs/specification/merkle.rst
similarity index 100%
rename from docs/merkle.rst
rename to docs/specification/merkle.rst
diff --git a/docs/rpc.rst b/docs/specification/rpc.rst
similarity index 100%
rename from docs/rpc.rst
rename to docs/specification/rpc.rst
diff --git a/docs/secure-p2p.rst b/docs/specification/secure-p2p.rst
similarity index 100%
rename from docs/secure-p2p.rst
rename to docs/specification/secure-p2p.rst
diff --git a/docs/validators.rst b/docs/specification/validators.rst
similarity index 100%
rename from docs/validators.rst
rename to docs/specification/validators.rst
diff --git a/docs/wire-protocol.rst b/docs/specification/wire-protocol.rst
similarity index 100%
rename from docs/wire-protocol.rst
rename to docs/specification/wire-protocol.rst
diff --git a/docs/using-tendermint.rst b/docs/using-tendermint.rst
index 0d17db611..1cb3ad86e 100644
--- a/docs/using-tendermint.rst
+++ b/docs/using-tendermint.rst
@@ -117,7 +117,7 @@ Configuration
 -------------
 
 Tendermint uses a ``config.toml`` for configutation. For details, see
-`the documentation <./configuration.html>`__.
+`the documentation <./specification/configuration.html>`__.
 
 Notable options include the socket address of the application
 (``proxy_app``), the listenting address of the tendermint peer
@@ -177,7 +177,7 @@ When ``tendermint init`` is run, both a ``genesis.json`` and
         "genesis_time": "0001-01-01T00:00:00.000Z",
         "validators": [
             {
-                "amount": 10,
+                "power": 10,
                 "name": "",
                 "pub_key": [
                     1,
@@ -310,7 +310,7 @@ then the new ``genesis.json`` will be:
         "genesis_time": "0001-01-01T00:00:00.000Z",
         "validators": [
             {
-                "amount": 10,
+                "power": 10,
                 "name": "",
                 "pub_key": [
                     1,
@@ -318,7 +318,7 @@ then the new ``genesis.json`` will be:
                 ]
             },
             {
-                "amount": 10,
+                "power": 10,
                 "name": "",
                 "pub_key": [
                     1,
diff --git a/glide.lock b/glide.lock
index 6ab0354eb..6e295a12a 100644
--- a/glide.lock
+++ b/glide.lock
@@ -1,41 +1,48 @@
-hash: 41581813ff97225a7feb86b5accb0fe4acb3e198b64592d7452240e9473c479f
-updated: 2017-08-03T19:17:16.410522485Z
+hash: e3649cac7b1b9a23c024a9d1bbebd5a147861d55da2bca77c95129b6021850b4
+updated: 2017-09-22T13:24:29.443800586-04:00
 imports:
 - name: github.com/btcsuite/btcd
-  version: b8df516b4b267acf2de46be593a9d948d1d2c420
+  version: 4803a8291c92a1d2d41041b942a9a9e37deab065
   subpackages:
   - btcec
-- name: github.com/btcsuite/fastsha256
-  version: 637e656429416087660c84436a2a035d69d54e2e
 - name: github.com/ebuchman/fail-test
   version: 95f809107225be108efcf10a3509e4ea6ceef3c4
 - name: github.com/fsnotify/fsnotify
   version: 4da3e2cfbabc9f751898f250b49f2439785783a1
 - name: github.com/go-kit/kit
-  version: d67bb4c202e3b91377d1079b110a6c9ce23ab2f8
+  version: 0d313fb5fb3a94d87d61e6434785264e87a5d740
   subpackages:
   - log
   - log/level
   - log/term
 - name: github.com/go-logfmt/logfmt
   version: 390ab7935ee28ec6b286364bba9b4dd6410cb3d5
+- name: github.com/go-playground/locales
+  version: 1e5f1161c6416a5ff48840eb8724a394e48cc534
+  subpackages:
+  - currency
+- name: github.com/go-playground/universal-translator
+  version: 71201497bace774495daed26a3874fd339e0b538
 - name: github.com/go-stack/stack
-  version: 100eb0c0a9c5b306ca2fb4f165df21d80ada4b82
+  version: 817915b46b97fd7bb80e8ab6b69f01a53ac3eebf
 - name: github.com/gogo/protobuf
-  version: 9df9efe4c742f1a2bfdedf1c3b6902fc6e814c6b
+  version: 2adc21fd136931e0388e278825291678e1d98309
   subpackages:
   - proto
 - name: github.com/golang/protobuf
-  version: 18c9bb3261723cd5401db4d0c9fbc5c3b6c70fe8
+  version: 130e6b02ab059e7b717a096f397c5b60111cae74
   subpackages:
   - proto
+  - ptypes
   - ptypes/any
+  - ptypes/duration
+  - ptypes/timestamp
 - name: github.com/golang/snappy
   version: 553a641470496b2327abcac10b36396bd98e45c9
 - name: github.com/gorilla/websocket
-  version: a91eba7f97777409bc2c443f5534d41dd20c5720
+  version: 6f34763140ed8887aed6a044912009832b4733d7
 - name: github.com/hashicorp/hcl
-  version: 392dba7d905ed5d04a5794ba89f558b27e2ba1ca
+  version: 68e816d1c783414e79bc65b3994d9ab6b0a722ab
   subpackages:
   - hcl/ast
   - hcl/parser
@@ -52,33 +59,31 @@ imports:
 - name: github.com/kr/logfmt
   version: b84e30acd515aadc4b783ad4ff83aff3299bdfe0
 - name: github.com/magiconair/properties
-  version: 51463bfca2576e06c62a8504b5c0f06d61312647
+  version: 8d7837e64d3c1ee4e54a880c5a920ab4316fc90a
 - name: github.com/mitchellh/mapstructure
-  version: cc8532a8e9a55ea36402aa21efdf403a60d34096
-- name: github.com/pelletier/go-buffruneio
-  version: c37440a7cf42ac63b919c752ca73a85067e05992
+  version: d0303fe809921458f417bcf828397a65db30a7e4
 - name: github.com/pelletier/go-toml
-  version: 5ccdfb18c776b740aecaf085c4d9a2779199c279
+  version: 1d6b12b7cb290426e27e6b4e38b89fcda3aeef03
 - name: github.com/pkg/errors
   version: 645ef00459ed84a119197bfb8d8205042c6df63d
 - name: github.com/rcrowley/go-metrics
   version: 1f30fe9094a513ce4c700b9a54458bbb0c96996c
 - name: github.com/spf13/afero
-  version: 9be650865eab0c12963d8753212f4f9c66cdcf12
+  version: ee1bd8ee15a1306d1f9201acc41ef39cd9f99a1b
   subpackages:
   - mem
 - name: github.com/spf13/cast
   version: acbeb36b902d72a7a4c18e8f3241075e7ab763e4
 - name: github.com/spf13/cobra
-  version: 4cdb38c072b86bf795d2c81de50784d9fdd6eb77
+  version: b78744579491c1ceeaaa3b40205e56b0591b93a3
 - name: github.com/spf13/jwalterweatherman
-  version: 8f07c835e5cc1450c082fe3a439cf87b0cbb2d99
+  version: 12bd96e66386c1960ab0f74ced1362f66f552f7b
 - name: github.com/spf13/pflag
-  version: e57e3eeb33f795204c1ca35f56c44f83227c6e66
+  version: 7aff26db30c1be810f9de5038ec5ef96ac41fd7c
 - name: github.com/spf13/viper
-  version: 0967fc9aceab2ce9da34061253ac10fb99bba5b2
+  version: 25b30aa063fc18e48662b86996252eabdcf2f0c7
 - name: github.com/syndtr/goleveldb
-  version: 8c81ea47d4c41a385645e133e15510fc6a2a74b4
+  version: b89cc31ef7977104127d34c1bd31ebd1a9db2199
   subpackages:
   - leveldb
   - leveldb/cache
@@ -93,7 +98,7 @@ imports:
   - leveldb/table
   - leveldb/util
 - name: github.com/tendermint/abci
-  version: 864d1f80b36b440bde030a5c18d8ac3aa8c2949d
+  version: 191c4b6d176169ffc7f9972d490fa362a3b7d940
   subpackages:
   - client
   - example/counter
@@ -106,21 +111,18 @@ imports:
   - edwards25519
   - extra25519
 - name: github.com/tendermint/go-crypto
-  version: 95b7c9e09c49b91bfbb71bb63dd514eb55450f16
+  version: 311e8c1bf00fa5868daad4f8ea56dcad539182c0
 - name: github.com/tendermint/go-wire
   version: 5f88da3dbc1a72844e6dfaf274ce87f851d488eb
   subpackages:
   - data
   - data/base58
 - name: github.com/tendermint/merkleeyes
-  version: 102aaf5a8ffda1846413fb22805a94def2045b9f
+  version: 2a93256d2c6fbcc3b55673c0d2b96a7e32c6238b
   subpackages:
-  - app
-  - client
   - iavl
-  - testutil
 - name: github.com/tendermint/tmlibs
-  version: 7ce4da1eee6004d627e780c8fe91e96d9b99e459
+  version: 9997e3a3b46db1d2f88aa9816ed0e7915dad6ac1
   subpackages:
   - autofile
   - cli
@@ -128,12 +130,13 @@ imports:
   - clist
   - common
   - db
+  - events
   - flowrate
   - log
   - merkle
   - test
 - name: golang.org/x/crypto
-  version: c7af5bf2638a1164f2eb5467c39c6cffbd13a02e
+  version: 7d9177d70076375b9a59c8fde23d52d9c4a7ecd5
   subpackages:
   - curve25519
   - nacl/box
@@ -144,7 +147,7 @@ imports:
   - ripemd160
   - salsa20/salsa
 - name: golang.org/x/net
-  version: feeb485667d1fdabe727840fe00adc22431bc86e
+  version: 0744d001aa8470aaa53df28d32e5ceeb8af9bd70
   subpackages:
   - context
   - http2
@@ -154,41 +157,46 @@ imports:
   - lex/httplex
   - trace
 - name: golang.org/x/sys
-  version: e62c3de784db939836898e5c19ffd41bece347da
+  version: 429f518978ab01db8bb6f44b66785088e7fba58b
   subpackages:
   - unix
 - name: golang.org/x/text
-  version: 470f45bf29f4147d6fbd7dfd0a02a848e49f5bf4
+  version: 1cbadb444a806fd9430d14ad08967ed91da4fa0a
   subpackages:
   - secure/bidirule
   - transform
   - unicode/bidi
   - unicode/norm
 - name: google.golang.org/genproto
-  version: 411e09b969b1170a9f0c467558eb4c4c110d9c77
+  version: 1e559d0a00eef8a9a43151db4665280bd8dd5886
   subpackages:
   - googleapis/rpc/status
 - name: google.golang.org/grpc
-  version: 844f573616520565fdc6fb4db242321b5456fd6d
+  version: d4b75ebd4f9f8c4a2b1cdadbdbe0d7920431ccca
   subpackages:
+  - balancer
   - codes
+  - connectivity
   - credentials
-  - grpclb/grpc_lb_v1
+  - grpclb/grpc_lb_v1/messages
   - grpclog
   - internal
   - keepalive
   - metadata
   - naming
   - peer
+  - resolver
   - stats
   - status
   - tap
   - transport
+- name: gopkg.in/go-playground/validator.v9
+  version: a021b2ec9a8a8bb970f3f15bc42617cb520e8a64
 - name: gopkg.in/yaml.v2
-  version: cd8b52f8269e0feb286dfeef29f8fe4d5b397e0b
+  version: eb3733d160e74a9c7e442f435eb3bea458e1d19f
 testImports:
 - name: github.com/davecgh/go-spew
-  version: 6d212800a42e8ab5c146b8ace3490ee17e5225f9
+  version: 04cdfd42973bb9c8589fd6a731800cf222fde1a9
   subpackages:
   - spew
 - name: github.com/pmezard/go-difflib
@@ -196,7 +204,7 @@ testImports:
   subpackages:
   - difflib
 - name: github.com/stretchr/testify
-  version: 69483b4bd14f5845b5a1e55bca19e954e827f1d0
+  version: 890a5c3458b43e6104ff5da8dfa139d013d77544
   subpackages:
   - assert
   - require
diff --git a/glide.yaml b/glide.yaml
index 78f9fec6e..58f25711d 100644
--- a/glide.yaml
+++ b/glide.yaml
@@ -14,19 +14,23 @@ import:
 - package: github.com/spf13/cobra
 - package: github.com/spf13/viper
 - package: github.com/tendermint/abci
-  version: v0.5.0
+  version: ~0.6.0
   subpackages:
   - client
   - example/dummy
   - types
 - package: github.com/tendermint/go-crypto
-  version: ~0.2.2
+  version: ~0.3.0
 - package: github.com/tendermint/go-wire
   version: ~0.6.2
   subpackages:
   - data
+- package: github.com/tendermint/merkleeyes
+  version: master
+  subpackages:
+  - iavl
 - package: github.com/tendermint/tmlibs
-  version: ~0.2.2
+  version: ~0.3.1
   subpackages:
   - autofile
   - cli
@@ -46,12 +50,6 @@ import:
   subpackages:
   - context
 - package: google.golang.org/grpc
-- package: github.com/tendermint/merkleeyes
-  version: ~0.2.4
-  subpackages:
-  - app
-  - iavl
-  - testutil
 testImport:
 - package: github.com/go-kit/kit
   subpackages:
diff --git a/mempool/reactor.go b/mempool/reactor.go
index 7dbfa2924..87bac5d92 100644
--- a/mempool/reactor.go
+++ b/mempool/reactor.go
@@ -60,18 +60,18 @@ func (memR *MempoolReactor) GetChannels() []*p2p.ChannelDescriptor {
 
 // AddPeer implements Reactor.
 // It starts a broadcast routine ensuring all txs are forwarded to the given peer.
-func (memR *MempoolReactor) AddPeer(peer *p2p.Peer) {
+func (memR *MempoolReactor) AddPeer(peer p2p.Peer) {
 	go memR.broadcastTxRoutine(peer)
 }
 
 // RemovePeer implements Reactor.
-func (memR *MempoolReactor) RemovePeer(peer *p2p.Peer, reason interface{}) {
+func (memR *MempoolReactor) RemovePeer(peer p2p.Peer, reason interface{}) {
 	// broadcast routine checks if peer is gone and returns
 }
 
 // Receive implements Reactor.
 // It adds any received transactions to the mempool.
-func (memR *MempoolReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte) {
+func (memR *MempoolReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
 	_, msg, err := DecodeMessage(msgBytes)
 	if err != nil {
 		memR.Logger.Error("Error decoding message", "err", err)
diff --git a/node/node.go b/node/node.go
index e0ddeb5d4..824a0926c 100644
--- a/node/node.go
+++ b/node/node.go
@@ -3,6 +3,7 @@ package node
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"net"
 	"net/http"
 	"strings"
@@ -10,11 +11,15 @@ import (
 	abci "github.com/tendermint/abci/types"
 	crypto "github.com/tendermint/go-crypto"
 	wire "github.com/tendermint/go-wire"
+	cmn "github.com/tendermint/tmlibs/common"
+	dbm "github.com/tendermint/tmlibs/db"
+	"github.com/tendermint/tmlibs/log"
+
 	bc "github.com/tendermint/tendermint/blockchain"
 	cfg "github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/consensus"
 	mempl "github.com/tendermint/tendermint/mempool"
-	p2p "github.com/tendermint/tendermint/p2p"
+	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/proxy"
 	rpccore "github.com/tendermint/tendermint/rpc/core"
 	grpccore "github.com/tendermint/tendermint/rpc/grpc"
@@ -26,20 +31,66 @@ import (
 	"github.com/tendermint/tendermint/state/txindex/null"
 	"github.com/tendermint/tendermint/types"
 	"github.com/tendermint/tendermint/version"
-	cmn "github.com/tendermint/tmlibs/common"
-	dbm "github.com/tendermint/tmlibs/db"
-	"github.com/tendermint/tmlibs/log"
 
 	_ "net/http/pprof"
 )
 
+//------------------------------------------------------------------------------
+
+// DBContext specifies config information for loading a new DB.
+type DBContext struct {
+	ID     string
+	Config *cfg.Config
+}
+
+// DBProvider takes a DBContext and returns an instantiated DB.
+type DBProvider func(*DBContext) (dbm.DB, error)
+
+// DefaultDBProvider returns a database using the DBBackend and DBDir
+// specified in the ctx.Config.
+func DefaultDBProvider(ctx *DBContext) (dbm.DB, error) {
+	return dbm.NewDB(ctx.ID, ctx.Config.DBBackend, ctx.Config.DBDir()), nil
+}
+
+// GenesisDocProvider returns a GenesisDoc.
+// It allows the GenesisDoc to be pulled from sources other than the
+// filesystem, for instance from a distributed key-value store cluster.
+type GenesisDocProvider func() (*types.GenesisDoc, error)
+
+// DefaultGenesisDocProviderFunc returns a GenesisDocProvider that loads
+// the GenesisDoc from the config.GenesisFile() on the filesystem.
+func DefaultGenesisDocProviderFunc(config *cfg.Config) GenesisDocProvider {
+	return func() (*types.GenesisDoc, error) {
+		return types.GenesisDocFromFile(config.GenesisFile())
+	}
+}
+
+// NodeProvider takes a config and a logger and returns a ready to go Node.
+type NodeProvider func(*cfg.Config, log.Logger) (*Node, error)
+
+// DefaultNewNode returns a Tendermint node with default settings for the
+// PrivValidator, ClientCreator, GenesisDoc, and DBProvider.
+// It implements NodeProvider.
+func DefaultNewNode(config *cfg.Config, logger log.Logger) (*Node, error) {
+	return NewNode(config,
+		types.LoadOrGenPrivValidatorFS(config.PrivValidatorFile()),
+		proxy.DefaultClientCreator(config.ProxyApp, config.ABCI, config.DBDir()),
+		DefaultGenesisDocProviderFunc(config),
+		DefaultDBProvider,
+		logger)
+}
+
+//------------------------------------------------------------------------------
+
+// Node is the highest level interface to a full Tendermint node.
+// It includes all configuration information and running services.
 type Node struct {
 	cmn.BaseService
 
 	// config
 	config        *cfg.Config
-	genesisDoc    *types.GenesisDoc    // initial validator set
-	privValidator *types.PrivValidator // local node's validator key
+	genesisDoc    *types.GenesisDoc   // initial validator set
+	privValidator types.PrivValidator // local node's validator key
 
 	// network
 	privKey  crypto.PrivKeyEd25519 // local node's p2p key
@@ -58,24 +109,42 @@ type Node struct {
 	txIndexer        txindex.TxIndexer
 }
 
-func NewNodeDefault(config *cfg.Config, logger log.Logger) *Node {
-	// Get PrivValidator
-	privValidator := types.LoadOrGenPrivValidator(config.PrivValidatorFile(), logger)
-	return NewNode(config, privValidator,
-		proxy.DefaultClientCreator(config.ProxyApp, config.ABCI, config.DBDir()), logger)
-}
+// NewNode returns a new, ready to go, Tendermint Node.
+func NewNode(config *cfg.Config,
+	privValidator types.PrivValidator,
+	clientCreator proxy.ClientCreator,
+	genesisDocProvider GenesisDocProvider,
+	dbProvider DBProvider,
+	logger log.Logger) (*Node, error) {
 
-func NewNode(config *cfg.Config, privValidator *types.PrivValidator, clientCreator proxy.ClientCreator, logger log.Logger) *Node {
 	// Get BlockStore
-	blockStoreDB := dbm.NewDB("blockstore", config.DBBackend, config.DBDir())
+	blockStoreDB, err := dbProvider(&DBContext{"blockstore", config})
+	if err != nil {
+		return nil, err
+	}
 	blockStore := bc.NewBlockStore(blockStoreDB)
 
 	consensusLogger := logger.With("module", "consensus")
 	stateLogger := logger.With("module", "state")
 
 	// Get State
-	stateDB := dbm.NewDB("state", config.DBBackend, config.DBDir())
-	state := sm.GetState(stateDB, config.GenesisFile())
+	stateDB, err := dbProvider(&DBContext{"state", config})
+	if err != nil {
+		return nil, err
+	}
+	state := sm.LoadState(stateDB)
+	if state == nil {
+		genDoc, err := genesisDocProvider()
+		if err != nil {
+			return nil, err
+		}
+		state, err = sm.MakeGenesisState(stateDB, genDoc)
+		if err != nil {
+			return nil, err
+		}
+		state.Save()
+	}
+
 	state.SetLogger(stateLogger)
 
 	// Create the proxyApp, which manages connections (consensus, mempool, query)
@@ -85,7 +154,7 @@ func NewNode(config *cfg.Config, privValidator *types.PrivValidator, clientCreat
 	proxyApp := proxy.NewAppConns(clientCreator, handshaker)
 	proxyApp.SetLogger(logger.With("module", "proxy"))
 	if _, err := proxyApp.Start(); err != nil {
-		cmn.Exit(cmn.Fmt("Error starting proxy app connections: %v", err))
+		return nil, fmt.Errorf("Error starting proxy app connections: %v", err)
 	}
 
 	// reload the state (it may have been updated by the handshake)
@@ -96,7 +165,10 @@ func NewNode(config *cfg.Config, privValidator *types.PrivValidator, clientCreat
 	var txIndexer txindex.TxIndexer
 	switch config.TxIndex {
 	case "kv":
-		store := dbm.NewDB("tx_index", config.DBBackend, config.DBDir())
+		store, err := dbProvider(&DBContext{"tx_index", config})
+		if err != nil {
+			return nil, err
+		}
 		txIndexer = kv.NewTxIndex(store)
 	default:
 		txIndexer = &null.TxIndex{}
@@ -109,9 +181,8 @@ func NewNode(config *cfg.Config, privValidator *types.PrivValidator, clientCreat
 	// Make event switch
 	eventSwitch := types.NewEventSwitch()
 	eventSwitch.SetLogger(logger.With("module", "types"))
-	_, err := eventSwitch.Start()
-	if err != nil {
-		cmn.Exit(cmn.Fmt("Failed to start switch: %v", err))
+	if _, err := eventSwitch.Start(); err != nil {
+		return nil, fmt.Errorf("Failed to start switch: %v", err)
 	}
 
 	// Decide whether to fast-sync or not
@@ -119,13 +190,13 @@ func NewNode(config *cfg.Config, privValidator *types.PrivValidator, clientCreat
 	fastSync := config.FastSync
 	if state.Validators.Size() == 1 {
 		addr, _ := state.Validators.GetByIndex(0)
-		if bytes.Equal(privValidator.Address, addr) {
+		if bytes.Equal(privValidator.GetAddress(), addr) {
 			fastSync = false
 		}
 	}
 
 	// Log whether this node is a validator or an observer
-	if state.Validators.HasAddress(privValidator.Address) {
+	if state.Validators.HasAddress(privValidator.GetAddress()) {
 		consensusLogger.Info("This node is a validator")
 	} else {
 		consensusLogger.Info("This node is not a validator")
@@ -232,12 +303,13 @@ func NewNode(config *cfg.Config, privValidator *types.PrivValidator, clientCreat
 		txIndexer:        txIndexer,
 	}
 	node.BaseService = *cmn.NewBaseService(logger, "Node", node)
-	return node
+	return node, nil
 }
 
+// OnStart starts the Node. It implements cmn.Service.
 func (n *Node) OnStart() error {
 	// Create & add listener
-	protocol, address := ProtocolAndAddress(n.config.P2P.ListenAddress)
+	protocol, address := cmn.ProtocolAndAddress(n.config.P2P.ListenAddress)
 	l := p2p.NewDefaultListener(protocol, address, n.config.P2P.SkipUPNP, n.Logger.With("module", "p2p"))
 	n.sw.AddListener(l)
 
@@ -270,6 +342,7 @@ func (n *Node) OnStart() error {
 	return nil
 }
 
+// OnStop stops the Node. It implements cmn.Service.
 func (n *Node) OnStop() {
 	n.BaseService.OnStop()
 
@@ -285,6 +358,7 @@ func (n *Node) OnStop() {
 	}
 }
 
+// RunForever waits for an interupt signal and stops the node.
 func (n *Node) RunForever() {
 	// Sleep forever and then...
 	cmn.TrapSignal(func() {
@@ -292,15 +366,15 @@ func (n *Node) RunForever() {
 	})
 }
 
-// Add the event switch to reactors, mempool, etc.
+// SetEventSwitch adds the event switch to reactors, mempool, etc.
 func SetEventSwitch(evsw types.EventSwitch, eventables ...types.Eventable) {
 	for _, e := range eventables {
 		e.SetEventSwitch(evsw)
 	}
 }
 
-// Add a Listener to accept inbound peer connections.
-// Add listeners before starting the Node.
+// AddListener adds a listener to accept inbound peer connections.
+// It should be called before starting the Node.
 // The first listener is the primary listener (in NodeInfo)
 func (n *Node) AddListener(l p2p.Listener) {
 	n.sw.AddListener(l)
@@ -314,7 +388,7 @@ func (n *Node) ConfigureRPC() {
 	rpccore.SetConsensusState(n.consensusState)
 	rpccore.SetMempool(n.mempoolReactor.Mempool)
 	rpccore.SetSwitch(n.sw)
-	rpccore.SetPubKey(n.privValidator.PubKey)
+	rpccore.SetPubKey(n.privValidator.GetPubKey())
 	rpccore.SetGenesisDoc(n.genesisDoc)
 	rpccore.SetAddrBook(n.addrBook)
 	rpccore.SetProxyAppQuery(n.proxyApp.Query())
@@ -360,39 +434,48 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 	return listeners, nil
 }
 
+// Switch returns the Node's Switch.
 func (n *Node) Switch() *p2p.Switch {
 	return n.sw
 }
 
+// BlockStore returns the Node's BlockStore.
 func (n *Node) BlockStore() *bc.BlockStore {
 	return n.blockStore
 }
 
+// ConsensusState returns the Node's ConsensusState.
 func (n *Node) ConsensusState() *consensus.ConsensusState {
 	return n.consensusState
 }
 
+// ConsensusReactor returns the Node's ConsensusReactor.
 func (n *Node) ConsensusReactor() *consensus.ConsensusReactor {
 	return n.consensusReactor
 }
 
+// MempoolReactor returns the Node's MempoolReactor.
 func (n *Node) MempoolReactor() *mempl.MempoolReactor {
 	return n.mempoolReactor
 }
 
+// EventSwitch returns the Node's EventSwitch.
 func (n *Node) EventSwitch() types.EventSwitch {
 	return n.evsw
 }
 
-// XXX: for convenience
-func (n *Node) PrivValidator() *types.PrivValidator {
+// PrivValidator returns the Node's PrivValidator.
+// XXX: for convenience only!
+func (n *Node) PrivValidator() types.PrivValidator {
 	return n.privValidator
 }
 
+// GenesisDoc returns the Node's GenesisDoc.
 func (n *Node) GenesisDoc() *types.GenesisDoc {
 	return n.genesisDoc
 }
 
+// ProxyApp returns the Node's AppConns, representing its connections to the ABCI application.
 func (n *Node) ProxyApp() proxy.AppConns {
 	return n.proxyApp
 }
@@ -442,22 +525,14 @@ func (n *Node) makeNodeInfo() *p2p.NodeInfo {
 
 //------------------------------------------------------------------------------
 
+// NodeInfo returns the Node's Info from the Switch.
 func (n *Node) NodeInfo() *p2p.NodeInfo {
 	return n.sw.NodeInfo()
 }
 
+// DialSeeds dials the given seeds on the Switch.
 func (n *Node) DialSeeds(seeds []string) error {
 	return n.sw.DialSeeds(n.addrBook, seeds)
 }
 
-// Defaults to tcp
-func ProtocolAndAddress(listenAddr string) (string, string) {
-	protocol, address := "tcp", listenAddr
-	parts := strings.SplitN(address, "://", 2)
-	if len(parts) == 2 {
-		protocol, address = parts[0], parts[1]
-	}
-	return protocol, address
-}
-
 //------------------------------------------------------------------------------
diff --git a/node/node_test.go b/node/node_test.go
index 3c751af6e..641e606c3 100644
--- a/node/node_test.go
+++ b/node/node_test.go
@@ -4,15 +4,19 @@ import (
 	"testing"
 	"time"
 
-	cfg "github.com/tendermint/tendermint/config"
+	"github.com/stretchr/testify/assert"
+
 	"github.com/tendermint/tmlibs/log"
+
+	cfg "github.com/tendermint/tendermint/config"
 )
 
 func TestNodeStartStop(t *testing.T) {
 	config := cfg.ResetTestRoot("node_node_test")
 
 	// Create & start node
-	n := NewNodeDefault(config, log.TestingLogger())
+	n, err := DefaultNewNode(config, log.TestingLogger())
+	assert.NoError(t, err, "expected no err on DefaultNewNode")
 	n.Start()
 	t.Logf("Started node %v", n.sw.NodeInfo())
 
diff --git a/p2p/listener.go b/p2p/listener.go
index 02d958d61..a382fbeda 100644
--- a/p2p/listener.go
+++ b/p2p/listener.go
@@ -87,7 +87,7 @@ func NewDefaultListener(protocol string, lAddr string, skipUPNP bool, logger log
 	}
 	// Otherwise just use the local address...
 	if extAddr == nil {
-		extAddr = getNaiveExternalAddress(listenerPort)
+		extAddr = getNaiveExternalAddress(listenerPort, false, logger)
 	}
 	if extAddr == nil {
 		cmn.PanicCrisis("Could not determine external address!")
@@ -197,7 +197,7 @@ func getUPNPExternalAddress(externalPort, internalPort int, logger log.Logger) *
 }
 
 // TODO: use syscalls: http://pastebin.com/9exZG4rh
-func getNaiveExternalAddress(port int) *NetAddress {
+func getNaiveExternalAddress(port int, settleForLocal bool, logger log.Logger) *NetAddress {
 	addrs, err := net.InterfaceAddrs()
 	if err != nil {
 		cmn.PanicCrisis(cmn.Fmt("Could not fetch interface addresses: %v", err))
@@ -209,10 +209,13 @@ func getNaiveExternalAddress(port int) *NetAddress {
 			continue
 		}
 		v4 := ipnet.IP.To4()
-		if v4 == nil || v4[0] == 127 {
+		if v4 == nil || (!settleForLocal && v4[0] == 127) {
 			continue
 		} // loopback
 		return NewNetAddressIPPort(ipnet.IP, uint16(port))
 	}
-	return nil
+
+	// try again, but settle for local
+	logger.Info("Node may not be connected to internet. Settling for local address")
+	return getNaiveExternalAddress(port, true, logger)
 }
diff --git a/p2p/peer.go b/p2p/peer.go
index c15f61d32..2b986a7a7 100644
--- a/p2p/peer.go
+++ b/p2p/peer.go
@@ -12,12 +12,29 @@ import (
 	cmn "github.com/tendermint/tmlibs/common"
 )
 
+// Peer is an interface representing a peer connected on a reactor.
+type Peer interface {
+	cmn.Service
+
+	Key() string
+	IsOutbound() bool
+	IsPersistent() bool
+	NodeInfo() *NodeInfo
+	Status() ConnectionStatus
+
+	Send(byte, interface{}) bool
+	TrySend(byte, interface{}) bool
+
+	Set(string, interface{})
+	Get(string) interface{}
+}
+
 // Peer could be marked as persistent, in which case you can use
 // Redial function to reconnect. Note that inbound peers can't be
 // made persistent. They should be made persistent on the other end.
 //
 // Before using a peer, you will need to perform a handshake on connection.
-type Peer struct {
+type peer struct {
 	cmn.BaseService
 
 	outbound bool
@@ -28,9 +45,9 @@ type Peer struct {
 	persistent bool
 	config     *PeerConfig
 
-	*NodeInfo
-	Key  string
-	Data *cmn.CMap // User data.
+	nodeInfo *NodeInfo
+	key      string
+	Data     *cmn.CMap // User data.
 }
 
 // PeerConfig is a Peer configuration.
@@ -60,7 +77,7 @@ func DefaultPeerConfig() *PeerConfig {
 }
 
 func newOutboundPeer(addr *NetAddress, reactorsByCh map[byte]Reactor, chDescs []*ChannelDescriptor,
-	onPeerError func(*Peer, interface{}), ourNodePrivKey crypto.PrivKeyEd25519, config *PeerConfig) (*Peer, error) {
+	onPeerError func(Peer, interface{}), ourNodePrivKey crypto.PrivKeyEd25519, config *PeerConfig) (*peer, error) {
 
 	conn, err := dial(addr, config)
 	if err != nil {
@@ -76,13 +93,13 @@ func newOutboundPeer(addr *NetAddress, reactorsByCh map[byte]Reactor, chDescs []
 }
 
 func newInboundPeer(conn net.Conn, reactorsByCh map[byte]Reactor, chDescs []*ChannelDescriptor,
-	onPeerError func(*Peer, interface{}), ourNodePrivKey crypto.PrivKeyEd25519, config *PeerConfig) (*Peer, error) {
+	onPeerError func(Peer, interface{}), ourNodePrivKey crypto.PrivKeyEd25519, config *PeerConfig) (*peer, error) {
 
 	return newPeerFromConnAndConfig(conn, false, reactorsByCh, chDescs, onPeerError, ourNodePrivKey, config)
 }
 
 func newPeerFromConnAndConfig(rawConn net.Conn, outbound bool, reactorsByCh map[byte]Reactor, chDescs []*ChannelDescriptor,
-	onPeerError func(*Peer, interface{}), ourNodePrivKey crypto.PrivKeyEd25519, config *PeerConfig) (*Peer, error) {
+	onPeerError func(Peer, interface{}), ourNodePrivKey crypto.PrivKeyEd25519, config *PeerConfig) (*peer, error) {
 
 	conn := rawConn
 
@@ -104,7 +121,7 @@ func newPeerFromConnAndConfig(rawConn net.Conn, outbound bool, reactorsByCh map[
 	}
 
 	// Key and NodeInfo are set after Handshake
-	p := &Peer{
+	p := &peer{
 		outbound: outbound,
 		conn:     conn,
 		config:   config,
@@ -119,12 +136,12 @@ func newPeerFromConnAndConfig(rawConn net.Conn, outbound bool, reactorsByCh map[
 }
 
 // CloseConn should be used when the peer was created, but never started.
-func (p *Peer) CloseConn() {
+func (p *peer) CloseConn() {
 	p.conn.Close()
 }
 
 // makePersistent marks the peer as persistent.
-func (p *Peer) makePersistent() {
+func (p *peer) makePersistent() {
 	if !p.outbound {
 		panic("inbound peers can't be made persistent")
 	}
@@ -133,13 +150,13 @@ func (p *Peer) makePersistent() {
 }
 
 // IsPersistent returns true if the peer is persitent, false otherwise.
-func (p *Peer) IsPersistent() bool {
+func (p *peer) IsPersistent() bool {
 	return p.persistent
 }
 
 // HandshakeTimeout performs a handshake between a given node and the peer.
 // NOTE: blocking
-func (p *Peer) HandshakeTimeout(ourNodeInfo *NodeInfo, timeout time.Duration) error {
+func (p *peer) HandshakeTimeout(ourNodeInfo *NodeInfo, timeout time.Duration) error {
 	// Set deadline for handshake so we don't block forever on conn.ReadFull
 	p.conn.SetDeadline(time.Now().Add(timeout))
 
@@ -176,19 +193,19 @@ func (p *Peer) HandshakeTimeout(ourNodeInfo *NodeInfo, timeout time.Duration) er
 
 	peerNodeInfo.RemoteAddr = p.Addr().String()
 
-	p.NodeInfo = peerNodeInfo
-	p.Key = peerNodeInfo.PubKey.KeyString()
+	p.nodeInfo = peerNodeInfo
+	p.key = peerNodeInfo.PubKey.KeyString()
 
 	return nil
 }
 
 // Addr returns peer's remote network address.
-func (p *Peer) Addr() net.Addr {
+func (p *peer) Addr() net.Addr {
 	return p.conn.RemoteAddr()
 }
 
 // PubKey returns peer's public key.
-func (p *Peer) PubKey() crypto.PubKeyEd25519 {
+func (p *peer) PubKey() crypto.PubKeyEd25519 {
 	if p.config.AuthEnc {
 		return p.conn.(*SecretConnection).RemotePubKey()
 	}
@@ -199,31 +216,31 @@ func (p *Peer) PubKey() crypto.PubKeyEd25519 {
 }
 
 // OnStart implements BaseService.
-func (p *Peer) OnStart() error {
+func (p *peer) OnStart() error {
 	p.BaseService.OnStart()
 	_, err := p.mconn.Start()
 	return err
 }
 
 // OnStop implements BaseService.
-func (p *Peer) OnStop() {
+func (p *peer) OnStop() {
 	p.BaseService.OnStop()
 	p.mconn.Stop()
 }
 
 // Connection returns underlying MConnection.
-func (p *Peer) Connection() *MConnection {
+func (p *peer) Connection() *MConnection {
 	return p.mconn
 }
 
 // IsOutbound returns true if the connection is outbound, false otherwise.
-func (p *Peer) IsOutbound() bool {
+func (p *peer) IsOutbound() bool {
 	return p.outbound
 }
 
 // Send msg to the channel identified by chID byte. Returns false if the send
 // queue is full after timeout, specified by MConnection.
-func (p *Peer) Send(chID byte, msg interface{}) bool {
+func (p *peer) Send(chID byte, msg interface{}) bool {
 	if !p.IsRunning() {
 		// see Switch#Broadcast, where we fetch the list of peers and loop over
 		// them - while we're looping, one peer may be removed and stopped.
@@ -234,7 +251,7 @@ func (p *Peer) Send(chID byte, msg interface{}) bool {
 
 // TrySend msg to the channel identified by chID byte. Immediately returns
 // false if the send queue is full.
-func (p *Peer) TrySend(chID byte, msg interface{}) bool {
+func (p *peer) TrySend(chID byte, msg interface{}) bool {
 	if !p.IsRunning() {
 		return false
 	}
@@ -242,7 +259,7 @@ func (p *Peer) TrySend(chID byte, msg interface{}) bool {
 }
 
 // CanSend returns true if the send queue is not full, false otherwise.
-func (p *Peer) CanSend(chID byte) bool {
+func (p *peer) CanSend(chID byte) bool {
 	if !p.IsRunning() {
 		return false
 	}
@@ -250,32 +267,53 @@ func (p *Peer) CanSend(chID byte) bool {
 }
 
 // WriteTo writes the peer's public key to w.
-func (p *Peer) WriteTo(w io.Writer) (n int64, err error) {
+func (p *peer) WriteTo(w io.Writer) (n int64, err error) {
 	var n_ int
-	wire.WriteString(p.Key, w, &n_, &err)
+	wire.WriteString(p.key, w, &n_, &err)
 	n += int64(n_)
 	return
 }
 
 // String representation.
-func (p *Peer) String() string {
+func (p *peer) String() string {
 	if p.outbound {
-		return fmt.Sprintf("Peer{%v %v out}", p.mconn, p.Key[:12])
+		return fmt.Sprintf("Peer{%v %v out}", p.mconn, p.key[:12])
 	}
 
-	return fmt.Sprintf("Peer{%v %v in}", p.mconn, p.Key[:12])
+	return fmt.Sprintf("Peer{%v %v in}", p.mconn, p.key[:12])
 }
 
 // Equals reports whenever 2 peers are actually represent the same node.
-func (p *Peer) Equals(other *Peer) bool {
-	return p.Key == other.Key
+func (p *peer) Equals(other Peer) bool {
+	return p.key == other.Key()
 }
 
 // Get the data for a given key.
-func (p *Peer) Get(key string) interface{} {
+func (p *peer) Get(key string) interface{} {
 	return p.Data.Get(key)
 }
 
+// Set sets the data for the given key.
+func (p *peer) Set(key string, data interface{}) {
+	p.Data.Set(key, data)
+}
+
+// Key returns the peer's id key.
+func (p *peer) Key() string {
+	return p.key
+}
+
+// NodeInfo returns a copy of the peer's NodeInfo.
+func (p *peer) NodeInfo() *NodeInfo {
+	n := *p.nodeInfo // copy
+	return &n
+}
+
+// Status returns the peer's ConnectionStatus.
+func (p *peer) Status() ConnectionStatus {
+	return p.mconn.Status()
+}
+
 func dial(addr *NetAddress, config *PeerConfig) (net.Conn, error) {
 	conn, err := addr.DialTimeout(config.DialTimeout * time.Second)
 	if err != nil {
@@ -284,8 +322,8 @@ func dial(addr *NetAddress, config *PeerConfig) (net.Conn, error) {
 	return conn, nil
 }
 
-func createMConnection(conn net.Conn, p *Peer, reactorsByCh map[byte]Reactor, chDescs []*ChannelDescriptor,
-	onPeerError func(*Peer, interface{}), config *MConnConfig) *MConnection {
+func createMConnection(conn net.Conn, p *peer, reactorsByCh map[byte]Reactor, chDescs []*ChannelDescriptor,
+	onPeerError func(Peer, interface{}), config *MConnConfig) *MConnection {
 
 	onReceive := func(chID byte, msgBytes []byte) {
 		reactor := reactorsByCh[chID]
diff --git a/p2p/peer_set.go b/p2p/peer_set.go
index c5206d2d5..c21748cf9 100644
--- a/p2p/peer_set.go
+++ b/p2p/peer_set.go
@@ -7,8 +7,8 @@ import (
 // IPeerSet has a (immutable) subset of the methods of PeerSet.
 type IPeerSet interface {
 	Has(key string) bool
-	Get(key string) *Peer
-	List() []*Peer
+	Get(key string) Peer
+	List() []Peer
 	Size() int
 }
 
@@ -19,26 +19,28 @@ type IPeerSet interface {
 type PeerSet struct {
 	mtx    sync.Mutex
 	lookup map[string]*peerSetItem
-	list   []*Peer
+	list   []Peer
 }
 
 type peerSetItem struct {
-	peer  *Peer
+	peer  Peer
 	index int
 }
 
+// NewPeerSet creates a new peerSet with a list of initial capacity of 256 items.
 func NewPeerSet() *PeerSet {
 	return &PeerSet{
 		lookup: make(map[string]*peerSetItem),
-		list:   make([]*Peer, 0, 256),
+		list:   make([]Peer, 0, 256),
 	}
 }
 
-// Returns false if peer with key (PubKeyEd25519) is already set
-func (ps *PeerSet) Add(peer *Peer) error {
+// Add adds the peer to the PeerSet.
+// It returns ErrSwitchDuplicatePeer if the peer is already present.
+func (ps *PeerSet) Add(peer Peer) error {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()
-	if ps.lookup[peer.Key] != nil {
+	if ps.lookup[peer.Key()] != nil {
 		return ErrSwitchDuplicatePeer
 	}
 
@@ -46,18 +48,21 @@ func (ps *PeerSet) Add(peer *Peer) error {
 	// Appending is safe even with other goroutines
 	// iterating over the ps.list slice.
 	ps.list = append(ps.list, peer)
-	ps.lookup[peer.Key] = &peerSetItem{peer, index}
+	ps.lookup[peer.Key()] = &peerSetItem{peer, index}
 	return nil
 }
 
+// Has returns true iff the PeerSet contains
+// the peer referred to by this peerKey.
 func (ps *PeerSet) Has(peerKey string) bool {
 	ps.mtx.Lock()
-	defer ps.mtx.Unlock()
 	_, ok := ps.lookup[peerKey]
+	ps.mtx.Unlock()
 	return ok
 }
 
-func (ps *PeerSet) Get(peerKey string) *Peer {
+// Get looks up a peer by the provided peerKey.
+func (ps *PeerSet) Get(peerKey string) Peer {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()
 	item, ok := ps.lookup[peerKey]
@@ -68,45 +73,46 @@ func (ps *PeerSet) Get(peerKey string) *Peer {
 	}
 }
 
-func (ps *PeerSet) Remove(peer *Peer) {
+// Remove discards peer by its Key, if the peer was previously memoized.
+func (ps *PeerSet) Remove(peer Peer) {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()
-	item := ps.lookup[peer.Key]
+	item := ps.lookup[peer.Key()]
 	if item == nil {
 		return
 	}
 
 	index := item.index
-	// Copy the list but without the last element.
-	// (we must copy because we're mutating the list)
-	newList := make([]*Peer, len(ps.list)-1)
+	// Create a new copy of the list but with one less item.
+	// (we must copy because we'll be mutating the list).
+	newList := make([]Peer, len(ps.list)-1)
 	copy(newList, ps.list)
 	// If it's the last peer, that's an easy special case.
 	if index == len(ps.list)-1 {
 		ps.list = newList
-		delete(ps.lookup, peer.Key)
+		delete(ps.lookup, peer.Key())
 		return
 	}
 
-	// Move the last item from ps.list to "index" in list.
+	// Replace the popped item with the last item in the old list.
 	lastPeer := ps.list[len(ps.list)-1]
-	lastPeerKey := lastPeer.Key
+	lastPeerKey := lastPeer.Key()
 	lastPeerItem := ps.lookup[lastPeerKey]
 	newList[index] = lastPeer
 	lastPeerItem.index = index
 	ps.list = newList
-	delete(ps.lookup, peer.Key)
-
+	delete(ps.lookup, peer.Key())
 }
 
+// Size returns the number of unique items in the peerSet.
 func (ps *PeerSet) Size() int {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()
 	return len(ps.list)
 }
 
-// threadsafe list of peers.
-func (ps *PeerSet) List() []*Peer {
+// List returns the threadsafe list of peers.
+func (ps *PeerSet) List() []Peer {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()
 	return ps.list
diff --git a/p2p/peer_set_test.go b/p2p/peer_set_test.go
index 9214b2eb4..e37455256 100644
--- a/p2p/peer_set_test.go
+++ b/p2p/peer_set_test.go
@@ -2,47 +2,69 @@ package p2p
 
 import (
 	"math/rand"
+	"sync"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
+
 	cmn "github.com/tendermint/tmlibs/common"
 )
 
 // Returns an empty dummy peer
-func randPeer() *Peer {
-	return &Peer{
-		Key: cmn.RandStr(12),
-		NodeInfo: &NodeInfo{
+func randPeer() *peer {
+	return &peer{
+		key: cmn.RandStr(12),
+		nodeInfo: &NodeInfo{
 			RemoteAddr: cmn.Fmt("%v.%v.%v.%v:46656", rand.Int()%256, rand.Int()%256, rand.Int()%256, rand.Int()%256),
 			ListenAddr: cmn.Fmt("%v.%v.%v.%v:46656", rand.Int()%256, rand.Int()%256, rand.Int()%256, rand.Int()%256),
 		},
 	}
 }
 
-func TestAddRemoveOne(t *testing.T) {
+func TestPeerSetAddRemoveOne(t *testing.T) {
+	t.Parallel()
 	peerSet := NewPeerSet()
 
-	peer := randPeer()
-	err := peerSet.Add(peer)
-	if err != nil {
-		t.Errorf("Failed to add new peer")
+	var peerList []Peer
+	for i := 0; i < 5; i++ {
+		p := randPeer()
+		peerSet.Add(p)
+		peerList = append(peerList, p)
 	}
-	if peerSet.Size() != 1 {
-		t.Errorf("Failed to add new peer and increment size")
+
+	n := len(peerList)
+	// 1. Test removing from the front
+	for i, peerAtFront := range peerList {
+		peerSet.Remove(peerAtFront)
+		wantSize := n - i - 1
+		for j := 0; j < 2; j++ {
+			assert.Equal(t, false, peerSet.Has(peerAtFront.Key()), "#%d Run #%d: failed to remove peer", i, j)
+			assert.Equal(t, wantSize, peerSet.Size(), "#%d Run #%d: failed to remove peer and decrement size", i, j)
+			// Test the route of removing the now non-existent element
+			peerSet.Remove(peerAtFront)
+		}
 	}
 
-	peerSet.Remove(peer)
-	if peerSet.Has(peer.Key) {
-		t.Errorf("Failed to remove peer")
+	// 2. Next we are testing removing the peer at the end
+	// a) Replenish the peerSet
+	for _, peer := range peerList {
+		peerSet.Add(peer)
 	}
-	if peerSet.Size() != 0 {
-		t.Errorf("Failed to remove peer and decrement size")
+
+	// b) In reverse, remove each element
+	for i := n - 1; i >= 0; i-- {
+		peerAtEnd := peerList[i]
+		peerSet.Remove(peerAtEnd)
+		assert.Equal(t, false, peerSet.Has(peerAtEnd.Key()), "#%d: failed to remove item at end", i)
+		assert.Equal(t, i, peerSet.Size(), "#%d: differing sizes after peerSet.Remove(atEndPeer)", i)
 	}
 }
 
-func TestAddRemoveMany(t *testing.T) {
+func TestPeerSetAddRemoveMany(t *testing.T) {
+	t.Parallel()
 	peerSet := NewPeerSet()
 
-	peers := []*Peer{}
+	peers := []Peer{}
 	N := 100
 	for i := 0; i < N; i++ {
 		peer := randPeer()
@@ -57,7 +79,7 @@ func TestAddRemoveMany(t *testing.T) {
 
 	for i, peer := range peers {
 		peerSet.Remove(peer)
-		if peerSet.Has(peer.Key) {
+		if peerSet.Has(peer.Key()) {
 			t.Errorf("Failed to remove peer")
 		}
 		if peerSet.Size() != len(peers)-i-1 {
@@ -65,3 +87,61 @@ func TestAddRemoveMany(t *testing.T) {
 		}
 	}
 }
+
+func TestPeerSetAddDuplicate(t *testing.T) {
+	t.Parallel()
+	peerSet := NewPeerSet()
+	peer := randPeer()
+
+	n := 20
+	errsChan := make(chan error)
+	// Add the same asynchronously to test the
+	// concurrent guarantees of our APIs, and
+	// our expectation in the end is that only
+	// one addition succeeded, but the rest are
+	// instances of ErrSwitchDuplicatePeer.
+	for i := 0; i < n; i++ {
+		go func() {
+			errsChan <- peerSet.Add(peer)
+		}()
+	}
+
+	// Now collect and tally the results
+	errsTally := make(map[error]int)
+	for i := 0; i < n; i++ {
+		err := <-errsChan
+		errsTally[err] += 1
+	}
+
+	// Our next procedure is to ensure that only one addition
+	// succeeded and that the rest are each ErrSwitchDuplicatePeer.
+	wantErrCount, gotErrCount := n-1, errsTally[ErrSwitchDuplicatePeer]
+	assert.Equal(t, wantErrCount, gotErrCount, "invalid ErrSwitchDuplicatePeer count")
+
+	wantNilErrCount, gotNilErrCount := 1, errsTally[nil]
+	assert.Equal(t, wantNilErrCount, gotNilErrCount, "invalid nil errCount")
+}
+
+func TestPeerSetGet(t *testing.T) {
+	t.Parallel()
+	peerSet := NewPeerSet()
+	peer := randPeer()
+	assert.Nil(t, peerSet.Get(peer.Key()), "expecting a nil lookup, before .Add")
+
+	if err := peerSet.Add(peer); err != nil {
+		t.Fatalf("Failed to add new peer: %v", err)
+	}
+
+	var wg sync.WaitGroup
+	for i := 0; i < 10; i++ {
+		// Add them asynchronously to test the
+		// concurrent guarantees of our APIs.
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			got, want := peerSet.Get(peer.Key()), peer
+			assert.Equal(t, got, want, "#%d: got=%v want=%v", i, got, want)
+		}(i)
+	}
+	wg.Wait()
+}
diff --git a/p2p/peer_test.go b/p2p/peer_test.go
index 347de784c..ba52b22a4 100644
--- a/p2p/peer_test.go
+++ b/p2p/peer_test.go
@@ -76,13 +76,13 @@ func TestPeerSend(t *testing.T) {
 	assert.True(p.Send(0x01, "Asylum"))
 }
 
-func createOutboundPeerAndPerformHandshake(addr *NetAddress, config *PeerConfig) (*Peer, error) {
+func createOutboundPeerAndPerformHandshake(addr *NetAddress, config *PeerConfig) (*peer, error) {
 	chDescs := []*ChannelDescriptor{
 		&ChannelDescriptor{ID: 0x01, Priority: 1},
 	}
 	reactorsByCh := map[byte]Reactor{0x01: NewTestReactor(chDescs, true)}
 	pk := crypto.GenPrivKeyEd25519()
-	p, err := newOutboundPeer(addr, reactorsByCh, chDescs, func(p *Peer, r interface{}) {}, pk, config)
+	p, err := newOutboundPeer(addr, reactorsByCh, chDescs, func(p Peer, r interface{}) {}, pk, config)
 	if err != nil {
 		return nil, err
 	}
@@ -133,7 +133,7 @@ func (p *remotePeer) accept(l net.Listener) {
 		if err != nil {
 			golog.Fatalf("Failed to accept conn: %+v", err)
 		}
-		peer, err := newInboundPeer(conn, make(map[byte]Reactor), make([]*ChannelDescriptor, 0), func(p *Peer, r interface{}) {}, p.PrivKey, p.Config)
+		peer, err := newInboundPeer(conn, make(map[byte]Reactor), make([]*ChannelDescriptor, 0), func(p Peer, r interface{}) {}, p.PrivKey, p.Config)
 		if err != nil {
 			golog.Fatalf("Failed to create a peer: %+v", err)
 		}
diff --git a/p2p/pex_reactor.go b/p2p/pex_reactor.go
index 30ebc3a7e..69ab55cc9 100644
--- a/p2p/pex_reactor.go
+++ b/p2p/pex_reactor.go
@@ -92,7 +92,7 @@ func (r *PEXReactor) GetChannels() []*ChannelDescriptor {
 
 // AddPeer implements Reactor by adding peer to the address book (if inbound)
 // or by requesting more addresses (if outbound).
-func (r *PEXReactor) AddPeer(p *Peer) {
+func (r *PEXReactor) AddPeer(p Peer) {
 	if p.IsOutbound() {
 		// For outbound peers, the address is already in the books.
 		// Either it was added in DialSeeds or when we
@@ -101,10 +101,10 @@ func (r *PEXReactor) AddPeer(p *Peer) {
 			r.RequestPEX(p)
 		}
 	} else { // For inbound connections, the peer is its own source
-		addr, err := NewNetAddressString(p.ListenAddr)
+		addr, err := NewNetAddressString(p.NodeInfo().ListenAddr)
 		if err != nil {
 			// this should never happen
-			r.Logger.Error("Error in AddPeer: invalid peer address", "addr", p.ListenAddr, "err", err)
+			r.Logger.Error("Error in AddPeer: invalid peer address", "addr", p.NodeInfo().ListenAddr, "err", err)
 			return
 		}
 		r.book.AddAddress(addr, addr)
@@ -112,15 +112,15 @@ func (r *PEXReactor) AddPeer(p *Peer) {
 }
 
 // RemovePeer implements Reactor.
-func (r *PEXReactor) RemovePeer(p *Peer, reason interface{}) {
+func (r *PEXReactor) RemovePeer(p Peer, reason interface{}) {
 	// If we aren't keeping track of local temp data for each peer here, then we
 	// don't have to do anything.
 }
 
 // Receive implements Reactor by handling incoming PEX messages.
-func (r *PEXReactor) Receive(chID byte, src *Peer, msgBytes []byte) {
-	srcAddr := src.Connection().RemoteAddress
-	srcAddrStr := srcAddr.String()
+func (r *PEXReactor) Receive(chID byte, src Peer, msgBytes []byte) {
+	srcAddrStr := src.NodeInfo().RemoteAddr
+	srcAddr, _ := NewNetAddressString(srcAddrStr)
 
 	r.IncrementMsgCountForPeer(srcAddrStr)
 	if r.ReachedMaxMsgCountForPeer(srcAddrStr) {
@@ -154,12 +154,12 @@ func (r *PEXReactor) Receive(chID byte, src *Peer, msgBytes []byte) {
 }
 
 // RequestPEX asks peer for more addresses.
-func (r *PEXReactor) RequestPEX(p *Peer) {
+func (r *PEXReactor) RequestPEX(p Peer) {
 	p.Send(PexChannel, struct{ PexMessage }{&pexRequestMessage{}})
 }
 
 // SendAddrs sends addrs to the peer.
-func (r *PEXReactor) SendAddrs(p *Peer, addrs []*NetAddress) {
+func (r *PEXReactor) SendAddrs(p Peer, addrs []*NetAddress) {
 	p.Send(PexChannel, struct{ PexMessage }{&pexAddrsMessage{Addrs: addrs}})
 }
 
diff --git a/p2p/pex_reactor_test.go b/p2p/pex_reactor_test.go
index 0748486e5..b2c15ed89 100644
--- a/p2p/pex_reactor_test.go
+++ b/p2p/pex_reactor_test.go
@@ -129,7 +129,7 @@ func TestPEXReactorReceive(t *testing.T) {
 	peer := createRandomPeer(false)
 
 	size := book.Size()
-	netAddr, _ := NewNetAddressString(peer.ListenAddr)
+	netAddr, _ := NewNetAddressString(peer.NodeInfo().ListenAddr)
 	addrs := []*NetAddress{netAddr}
 	msg := wire.BinaryBytes(struct{ PexMessage }{&pexAddrsMessage{Addrs: addrs}})
 	r.Receive(PexChannel, peer, msg)
@@ -159,16 +159,17 @@ func TestPEXReactorAbuseFromPeer(t *testing.T) {
 		r.Receive(PexChannel, peer, msg)
 	}
 
-	assert.True(r.ReachedMaxMsgCountForPeer(peer.ListenAddr))
+	assert.True(r.ReachedMaxMsgCountForPeer(peer.NodeInfo().ListenAddr))
 }
 
-func createRandomPeer(outbound bool) *Peer {
+func createRandomPeer(outbound bool) *peer {
 	addr := cmn.Fmt("%v.%v.%v.%v:46656", rand.Int()%256, rand.Int()%256, rand.Int()%256, rand.Int()%256)
 	netAddr, _ := NewNetAddressString(addr)
-	p := &Peer{
-		Key: cmn.RandStr(12),
-		NodeInfo: &NodeInfo{
+	p := &peer{
+		key: cmn.RandStr(12),
+		nodeInfo: &NodeInfo{
 			ListenAddr: addr,
+			RemoteAddr: netAddr.String(),
 		},
 		outbound: outbound,
 		mconn:    &MConnection{RemoteAddress: netAddr},
diff --git a/p2p/switch.go b/p2p/switch.go
index d92dd6370..9ede8c108 100644
--- a/p2p/switch.go
+++ b/p2p/switch.go
@@ -22,9 +22,9 @@ type Reactor interface {
 
 	SetSwitch(*Switch)
 	GetChannels() []*ChannelDescriptor
-	AddPeer(peer *Peer)
-	RemovePeer(peer *Peer, reason interface{})
-	Receive(chID byte, peer *Peer, msgBytes []byte)
+	AddPeer(peer Peer)
+	RemovePeer(peer Peer, reason interface{})
+	Receive(chID byte, peer Peer, msgBytes []byte)
 }
 
 //--------------------------------------
@@ -44,10 +44,10 @@ func NewBaseReactor(name string, impl Reactor) *BaseReactor {
 func (br *BaseReactor) SetSwitch(sw *Switch) {
 	br.Switch = sw
 }
-func (_ *BaseReactor) GetChannels() []*ChannelDescriptor              { return nil }
-func (_ *BaseReactor) AddPeer(peer *Peer)                             {}
-func (_ *BaseReactor) RemovePeer(peer *Peer, reason interface{})      {}
-func (_ *BaseReactor) Receive(chID byte, peer *Peer, msgBytes []byte) {}
+func (_ *BaseReactor) GetChannels() []*ChannelDescriptor             { return nil }
+func (_ *BaseReactor) AddPeer(peer Peer)                             {}
+func (_ *BaseReactor) RemovePeer(peer Peer, reason interface{})      {}
+func (_ *BaseReactor) Receive(chID byte, peer Peer, msgBytes []byte) {}
 
 //-----------------------------------------------------------------------------
 
@@ -209,11 +209,12 @@ func (sw *Switch) OnStop() {
 	}
 }
 
-// AddPeer checks the given peer's validity, performs a handshake, and adds the peer to the switch
+// addPeer checks the given peer's validity, performs a handshake, and adds the peer to the switch
 // and to all registered reactors.
 // NOTE: This performs a blocking handshake before the peer is added.
 // CONTRACT: If error is returned, peer is nil, and conn is immediately closed.
-func (sw *Switch) AddPeer(peer *Peer) error {
+func (sw *Switch) addPeer(peer *peer) error {
+
 	if err := sw.FilterConnByAddr(peer.Addr()); err != nil {
 		return err
 	}
@@ -232,12 +233,12 @@ func (sw *Switch) AddPeer(peer *Peer) error {
 	}
 
 	// Check version, chain id
-	if err := sw.nodeInfo.CompatibleWith(peer.NodeInfo); err != nil {
+	if err := sw.nodeInfo.CompatibleWith(peer.NodeInfo()); err != nil {
 		return err
 	}
 
 	// Check for duplicate peer
-	if sw.peers.Has(peer.Key) {
+	if sw.peers.Has(peer.Key()) {
 		return ErrSwitchDuplicatePeer
 
 	}
@@ -285,7 +286,7 @@ func (sw *Switch) SetPubKeyFilter(f func(crypto.PubKeyEd25519) error) {
 	sw.filterConnByPubKey = f
 }
 
-func (sw *Switch) startInitPeer(peer *Peer) {
+func (sw *Switch) startInitPeer(peer *peer) {
 	peer.Start() // spawn send/recv routines
 	for _, reactor := range sw.reactors {
 		reactor.AddPeer(peer)
@@ -335,9 +336,9 @@ func (sw *Switch) dialSeed(addr *NetAddress) {
 	}
 }
 
-// DialPeerWithAddress dials the given peer and runs sw.AddPeer if it connects successfully.
+// DialPeerWithAddress dials the given peer and runs sw.addPeer if it connects successfully.
 // If `persistent == true`, the switch will always try to reconnect to this peer if the connection ever fails.
-func (sw *Switch) DialPeerWithAddress(addr *NetAddress, persistent bool) (*Peer, error) {
+func (sw *Switch) DialPeerWithAddress(addr *NetAddress, persistent bool) (Peer, error) {
 	sw.dialing.Set(addr.IP.String(), addr)
 	defer sw.dialing.Delete(addr.IP.String())
 
@@ -351,7 +352,7 @@ func (sw *Switch) DialPeerWithAddress(addr *NetAddress, persistent bool) (*Peer,
 	if persistent {
 		peer.makePersistent()
 	}
-	err = sw.AddPeer(peer)
+	err = sw.addPeer(peer)
 	if err != nil {
 		sw.Logger.Error("Failed to add peer", "address", addr, "err", err)
 		peer.CloseConn()
@@ -375,7 +376,7 @@ func (sw *Switch) Broadcast(chID byte, msg interface{}) chan bool {
 	successChan := make(chan bool, len(sw.peers.List()))
 	sw.Logger.Debug("Broadcast", "channel", chID, "msg", msg)
 	for _, peer := range sw.peers.List() {
-		go func(peer *Peer) {
+		go func(peer Peer) {
 			success := peer.Send(chID, msg)
 			successChan <- success
 		}(peer)
@@ -387,7 +388,7 @@ func (sw *Switch) Broadcast(chID byte, msg interface{}) chan bool {
 func (sw *Switch) NumPeers() (outbound, inbound, dialing int) {
 	peers := sw.peers.List()
 	for _, peer := range peers {
-		if peer.outbound {
+		if peer.IsOutbound() {
 			outbound++
 		} else {
 			inbound++
@@ -405,8 +406,8 @@ func (sw *Switch) Peers() IPeerSet {
 // StopPeerForError disconnects from a peer due to external error.
 // If the peer is persistent, it will attempt to reconnect.
 // TODO: make record depending on reason.
-func (sw *Switch) StopPeerForError(peer *Peer, reason interface{}) {
-	addr := NewNetAddress(peer.Addr())
+func (sw *Switch) StopPeerForError(peer Peer, reason interface{}) {
+	addr, _ := NewNetAddressString(peer.NodeInfo().RemoteAddr)
 	sw.Logger.Error("Stopping peer for error", "peer", peer, "err", reason)
 	sw.stopAndRemovePeer(peer, reason)
 
@@ -438,12 +439,12 @@ func (sw *Switch) StopPeerForError(peer *Peer, reason interface{}) {
 
 // StopPeerGracefully disconnects from a peer gracefully.
 // TODO: handle graceful disconnects.
-func (sw *Switch) StopPeerGracefully(peer *Peer) {
+func (sw *Switch) StopPeerGracefully(peer Peer) {
 	sw.Logger.Info("Stopping peer gracefully")
 	sw.stopAndRemovePeer(peer, nil)
 }
 
-func (sw *Switch) stopAndRemovePeer(peer *Peer, reason interface{}) {
+func (sw *Switch) stopAndRemovePeer(peer Peer, reason interface{}) {
 	sw.peers.Remove(peer)
 	peer.Stop()
 	for _, reactor := range sw.reactors {
@@ -483,11 +484,11 @@ func (sw *Switch) listenerRoutine(l Listener) {
 //-----------------------------------------------------------------------------
 
 type SwitchEventNewPeer struct {
-	Peer *Peer
+	Peer Peer
 }
 
 type SwitchEventDonePeer struct {
-	Peer  *Peer
+	Peer  Peer
 	Error interface{}
 }
 
@@ -581,7 +582,7 @@ func (sw *Switch) addPeerWithConnection(conn net.Conn) error {
 		return err
 	}
 	peer.SetLogger(sw.Logger.With("peer", conn.RemoteAddr()))
-	if err = sw.AddPeer(peer); err != nil {
+	if err = sw.addPeer(peer); err != nil {
 		conn.Close()
 		return err
 	}
@@ -596,7 +597,7 @@ func (sw *Switch) addPeerWithConnectionAndConfig(conn net.Conn, config *PeerConf
 		return err
 	}
 	peer.SetLogger(sw.Logger.With("peer", conn.RemoteAddr()))
-	if err = sw.AddPeer(peer); err != nil {
+	if err = sw.addPeer(peer); err != nil {
 		conn.Close()
 		return err
 	}
diff --git a/p2p/switch_test.go b/p2p/switch_test.go
index c686f9e46..115811b04 100644
--- a/p2p/switch_test.go
+++ b/p2p/switch_test.go
@@ -37,8 +37,8 @@ type TestReactor struct {
 
 	mtx          sync.Mutex
 	channels     []*ChannelDescriptor
-	peersAdded   []*Peer
-	peersRemoved []*Peer
+	peersAdded   []Peer
+	peersRemoved []Peer
 	logMessages  bool
 	msgsCounter  int
 	msgsReceived map[byte][]PeerMessage
@@ -59,24 +59,24 @@ func (tr *TestReactor) GetChannels() []*ChannelDescriptor {
 	return tr.channels
 }
 
-func (tr *TestReactor) AddPeer(peer *Peer) {
+func (tr *TestReactor) AddPeer(peer Peer) {
 	tr.mtx.Lock()
 	defer tr.mtx.Unlock()
 	tr.peersAdded = append(tr.peersAdded, peer)
 }
 
-func (tr *TestReactor) RemovePeer(peer *Peer, reason interface{}) {
+func (tr *TestReactor) RemovePeer(peer Peer, reason interface{}) {
 	tr.mtx.Lock()
 	defer tr.mtx.Unlock()
 	tr.peersRemoved = append(tr.peersRemoved, peer)
 }
 
-func (tr *TestReactor) Receive(chID byte, peer *Peer, msgBytes []byte) {
+func (tr *TestReactor) Receive(chID byte, peer Peer, msgBytes []byte) {
 	if tr.logMessages {
 		tr.mtx.Lock()
 		defer tr.mtx.Unlock()
 		//fmt.Printf("Received: %X, %X\n", chID, msgBytes)
-		tr.msgsReceived[chID] = append(tr.msgsReceived[chID], PeerMessage{peer.Key, msgBytes, tr.msgsCounter})
+		tr.msgsReceived[chID] = append(tr.msgsReceived[chID], PeerMessage{peer.Key(), msgBytes, tr.msgsCounter})
 		tr.msgsCounter++
 	}
 }
@@ -246,7 +246,7 @@ func TestSwitchStopsNonPersistentPeerOnError(t *testing.T) {
 
 	peer, err := newOutboundPeer(rp.Addr(), sw.reactorsByCh, sw.chDescs, sw.StopPeerForError, sw.nodePrivKey, DefaultPeerConfig())
 	require.Nil(err)
-	err = sw.AddPeer(peer)
+	err = sw.addPeer(peer)
 	require.Nil(err)
 
 	// simulate failure by closing connection
@@ -273,7 +273,7 @@ func TestSwitchReconnectsToPersistentPeer(t *testing.T) {
 	peer, err := newOutboundPeer(rp.Addr(), sw.reactorsByCh, sw.chDescs, sw.StopPeerForError, sw.nodePrivKey, DefaultPeerConfig())
 	peer.makePersistent()
 	require.Nil(err)
-	err = sw.AddPeer(peer)
+	err = sw.addPeer(peer)
 	require.Nil(err)
 
 	// simulate failure by closing connection
diff --git a/proxy/app_conn.go b/proxy/app_conn.go
index 8b007737c..9121e8db8 100644
--- a/proxy/app_conn.go
+++ b/proxy/app_conn.go
@@ -12,9 +12,9 @@ type AppConnConsensus interface {
 	SetResponseCallback(abcicli.Callback)
 	Error() error
 
-	InitChainSync(validators []*types.Validator) (err error)
+	InitChainSync(types.RequestInitChain) (err error)
 
-	BeginBlockSync(hash []byte, header *types.Header) (err error)
+	BeginBlockSync(types.RequestBeginBlock) (err error)
 	DeliverTxAsync(tx []byte) *abcicli.ReqRes
 	EndBlockSync(height uint64) (types.ResponseEndBlock, error)
 	CommitSync() (res types.Result)
@@ -34,8 +34,8 @@ type AppConnQuery interface {
 	Error() error
 
 	EchoSync(string) (res types.Result)
-	InfoSync() (resInfo types.ResponseInfo, err error)
-	QuerySync(reqQuery types.RequestQuery) (resQuery types.ResponseQuery, err error)
+	InfoSync(types.RequestInfo) (types.ResponseInfo, error)
+	QuerySync(types.RequestQuery) (types.ResponseQuery, error)
 
 	//	SetOptionSync(key string, value string) (res types.Result)
 }
@@ -61,12 +61,12 @@ func (app *appConnConsensus) Error() error {
 	return app.appConn.Error()
 }
 
-func (app *appConnConsensus) InitChainSync(validators []*types.Validator) (err error) {
-	return app.appConn.InitChainSync(validators)
+func (app *appConnConsensus) InitChainSync(req types.RequestInitChain) (err error) {
+	return app.appConn.InitChainSync(req)
 }
 
-func (app *appConnConsensus) BeginBlockSync(hash []byte, header *types.Header) (err error) {
-	return app.appConn.BeginBlockSync(hash, header)
+func (app *appConnConsensus) BeginBlockSync(req types.RequestBeginBlock) (err error) {
+	return app.appConn.BeginBlockSync(req)
 }
 
 func (app *appConnConsensus) DeliverTxAsync(tx []byte) *abcicli.ReqRes {
@@ -135,8 +135,8 @@ func (app *appConnQuery) EchoSync(msg string) (res types.Result) {
 	return app.appConn.EchoSync(msg)
 }
 
-func (app *appConnQuery) InfoSync() (types.ResponseInfo, error) {
-	return app.appConn.InfoSync()
+func (app *appConnQuery) InfoSync(req types.RequestInfo) (types.ResponseInfo, error) {
+	return app.appConn.InfoSync(req)
 }
 
 func (app *appConnQuery) QuerySync(reqQuery types.RequestQuery) (types.ResponseQuery, error) {
diff --git a/proxy/app_conn_test.go b/proxy/app_conn_test.go
index 159e0b3e1..0c700140b 100644
--- a/proxy/app_conn_test.go
+++ b/proxy/app_conn_test.go
@@ -17,7 +17,7 @@ import (
 type AppConnTest interface {
 	EchoAsync(string) *abcicli.ReqRes
 	FlushSync() error
-	InfoSync() (types.ResponseInfo, error)
+	InfoSync(types.RequestInfo) (types.ResponseInfo, error)
 }
 
 type appConnTest struct {
@@ -36,8 +36,8 @@ func (app *appConnTest) FlushSync() error {
 	return app.appConn.FlushSync()
 }
 
-func (app *appConnTest) InfoSync() (types.ResponseInfo, error) {
-	return app.appConn.InfoSync()
+func (app *appConnTest) InfoSync(req types.RequestInfo) (types.ResponseInfo, error) {
+	return app.appConn.InfoSync(req)
 }
 
 //----------------------------------------
@@ -109,7 +109,7 @@ func BenchmarkEcho(b *testing.B) {
 	proxy.FlushSync()
 
 	b.StopTimer()
-	// info := proxy.InfoSync()
+	// info := proxy.InfoSync(types.RequestInfo{""})
 	//b.Log("N: ", b.N, info)
 }
 
@@ -138,7 +138,7 @@ func TestInfo(t *testing.T) {
 	proxy := NewAppConnTest(cli)
 	t.Log("Connected")
 
-	resInfo, err := proxy.InfoSync()
+	resInfo, err := proxy.InfoSync(types.RequestInfo{""})
 	if err != nil {
 		t.Errorf("Unexpected error: %v", err)
 	}
diff --git a/rpc/client/event_test.go b/rpc/client/event_test.go
index ad5522e49..a10021821 100644
--- a/rpc/client/event_test.go
+++ b/rpc/client/event_test.go
@@ -5,11 +5,20 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/require"
-	merktest "github.com/tendermint/merkleeyes/testutil"
+
+	cmn "github.com/tendermint/tmlibs/common"
+
 	"github.com/tendermint/tendermint/rpc/client"
 	"github.com/tendermint/tendermint/types"
 )
 
+// MakeTxKV returns a text transaction, allong with expected key, value pair
+func MakeTxKV() ([]byte, []byte, []byte) {
+	k := []byte(cmn.RandStr(8))
+	v := []byte(cmn.RandStr(8))
+	return k, v, append(k, append([]byte("="), v...)...)
+}
+
 func TestHeaderEvents(t *testing.T) {
 	require := require.New(t)
 	for i, c := range GetClients() {
@@ -76,7 +85,7 @@ func TestTxEventsSentWithBroadcastTxAsync(t *testing.T) {
 		}
 
 		// make the tx
-		_, _, tx := merktest.MakeTxKV()
+		_, _, tx := MakeTxKV()
 		evtTyp := types.EventStringTx(types.Tx(tx))
 
 		// send async
@@ -109,7 +118,7 @@ func TestTxEventsSentWithBroadcastTxSync(t *testing.T) {
 		}
 
 		// make the tx
-		_, _, tx := merktest.MakeTxKV()
+		_, _, tx := MakeTxKV()
 		evtTyp := types.EventStringTx(types.Tx(tx))
 
 		// send async
diff --git a/rpc/client/httpclient.go b/rpc/client/httpclient.go
index 9623229e6..7f29183d5 100644
--- a/rpc/client/httpclient.go
+++ b/rpc/client/httpclient.go
@@ -143,7 +143,7 @@ func (c *HTTP) Genesis() (*ctypes.ResultGenesis, error) {
 	return result, nil
 }
 
-func (c *HTTP) Block(height int) (*ctypes.ResultBlock, error) {
+func (c *HTTP) Block(height *int) (*ctypes.ResultBlock, error) {
 	result := new(ctypes.ResultBlock)
 	_, err := c.rpc.Call("block", map[string]interface{}{"height": height}, result)
 	if err != nil {
@@ -152,7 +152,7 @@ func (c *HTTP) Block(height int) (*ctypes.ResultBlock, error) {
 	return result, nil
 }
 
-func (c *HTTP) Commit(height int) (*ctypes.ResultCommit, error) {
+func (c *HTTP) Commit(height *int) (*ctypes.ResultCommit, error) {
 	result := new(ctypes.ResultCommit)
 	_, err := c.rpc.Call("commit", map[string]interface{}{"height": height}, result)
 	if err != nil {
@@ -174,9 +174,9 @@ func (c *HTTP) Tx(hash []byte, prove bool) (*ctypes.ResultTx, error) {
 	return result, nil
 }
 
-func (c *HTTP) Validators() (*ctypes.ResultValidators, error) {
+func (c *HTTP) Validators(height *int) (*ctypes.ResultValidators, error) {
 	result := new(ctypes.ResultValidators)
-	_, err := c.rpc.Call("validators", map[string]interface{}{}, result)
+	_, err := c.rpc.Call("validators", map[string]interface{}{"height": height}, result)
 	if err != nil {
 		return nil, errors.Wrap(err, "Validators")
 	}
diff --git a/rpc/client/interface.go b/rpc/client/interface.go
index 0cd0f29bb..ed7ccabaf 100644
--- a/rpc/client/interface.go
+++ b/rpc/client/interface.go
@@ -42,9 +42,9 @@ type ABCIClient interface {
 // SignClient groups together the interfaces need to get valid
 // signatures and prove anything about the chain
 type SignClient interface {
-	Block(height int) (*ctypes.ResultBlock, error)
-	Commit(height int) (*ctypes.ResultCommit, error)
-	Validators() (*ctypes.ResultValidators, error)
+	Block(height *int) (*ctypes.ResultBlock, error)
+	Commit(height *int) (*ctypes.ResultCommit, error)
+	Validators(height *int) (*ctypes.ResultValidators, error)
 	Tx(hash []byte, prove bool) (*ctypes.ResultTx, error)
 }
 
diff --git a/rpc/client/localclient.go b/rpc/client/localclient.go
index f4eb00d78..134f935ca 100644
--- a/rpc/client/localclient.go
+++ b/rpc/client/localclient.go
@@ -93,16 +93,16 @@ func (c Local) Genesis() (*ctypes.ResultGenesis, error) {
 	return core.Genesis()
 }
 
-func (c Local) Block(height int) (*ctypes.ResultBlock, error) {
+func (c Local) Block(height *int) (*ctypes.ResultBlock, error) {
 	return core.Block(height)
 }
 
-func (c Local) Commit(height int) (*ctypes.ResultCommit, error) {
+func (c Local) Commit(height *int) (*ctypes.ResultCommit, error) {
 	return core.Commit(height)
 }
 
-func (c Local) Validators() (*ctypes.ResultValidators, error) {
-	return core.Validators()
+func (c Local) Validators(height *int) (*ctypes.ResultValidators, error) {
+	return core.Validators(height)
 }
 
 func (c Local) Tx(hash []byte, prove bool) (*ctypes.ResultTx, error) {
diff --git a/rpc/client/main_test.go b/rpc/client/main_test.go
index 5ec911e5d..7c5acd390 100644
--- a/rpc/client/main_test.go
+++ b/rpc/client/main_test.go
@@ -4,7 +4,7 @@ import (
 	"os"
 	"testing"
 
-	meapp "github.com/tendermint/merkleeyes/app"
+	"github.com/tendermint/abci/example/dummy"
 	nm "github.com/tendermint/tendermint/node"
 	rpctest "github.com/tendermint/tendermint/rpc/test"
 )
@@ -12,8 +12,8 @@ import (
 var node *nm.Node
 
 func TestMain(m *testing.M) {
-	// start a tendermint node (and merkleeyes) in the background to test against
-	app := meapp.NewMerkleEyesApp("", 100)
+	// start a tendermint node (and dummy) in the background to test against
+	app := dummy.NewDummyApplication()
 	node = rpctest.StartTendermint(app)
 	code := m.Run()
 
diff --git a/rpc/client/mock/abci.go b/rpc/client/mock/abci.go
index 71fa90b2a..db3fa4f1d 100644
--- a/rpc/client/mock/abci.go
+++ b/rpc/client/mock/abci.go
@@ -6,6 +6,7 @@ import (
 	"github.com/tendermint/tendermint/rpc/client"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	"github.com/tendermint/tendermint/types"
+	"github.com/tendermint/tendermint/version"
 )
 
 // ABCIApp will send all abci related request to the named app,
@@ -20,7 +21,7 @@ func (a ABCIApp) _assertABCIClient() client.ABCIClient {
 }
 
 func (a ABCIApp) ABCIInfo() (*ctypes.ResultABCIInfo, error) {
-	return &ctypes.ResultABCIInfo{a.App.Info()}, nil
+	return &ctypes.ResultABCIInfo{a.App.Info(abci.RequestInfo{version.Version})}, nil
 }
 
 func (a ABCIApp) ABCIQuery(path string, data data.Bytes, prove bool) (*ctypes.ResultABCIQuery, error) {
diff --git a/rpc/client/mock/client.go b/rpc/client/mock/client.go
index bf8d78dce..f32694edd 100644
--- a/rpc/client/mock/client.go
+++ b/rpc/client/mock/client.go
@@ -116,14 +116,14 @@ func (c Client) Genesis() (*ctypes.ResultGenesis, error) {
 	return core.Genesis()
 }
 
-func (c Client) Block(height int) (*ctypes.ResultBlock, error) {
+func (c Client) Block(height *int) (*ctypes.ResultBlock, error) {
 	return core.Block(height)
 }
 
-func (c Client) Commit(height int) (*ctypes.ResultCommit, error) {
+func (c Client) Commit(height *int) (*ctypes.ResultCommit, error) {
 	return core.Commit(height)
 }
 
-func (c Client) Validators() (*ctypes.ResultValidators, error) {
-	return core.Validators()
+func (c Client) Validators(height *int) (*ctypes.ResultValidators, error) {
+	return core.Validators(height)
 }
diff --git a/rpc/client/rpc_test.go b/rpc/client/rpc_test.go
index e82f8df42..77de9f6e8 100644
--- a/rpc/client/rpc_test.go
+++ b/rpc/client/rpc_test.go
@@ -7,7 +7,6 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/tendermint/merkleeyes/iavl"
-	merktest "github.com/tendermint/merkleeyes/testutil"
 	"github.com/tendermint/tendermint/rpc/client"
 	rpctest "github.com/tendermint/tendermint/rpc/test"
 	"github.com/tendermint/tendermint/types"
@@ -49,7 +48,7 @@ func TestInfo(t *testing.T) {
 		require.Nil(t, err, "%d: %+v", i, err)
 		// TODO: this is not correct - fix merkleeyes!
 		// assert.EqualValues(t, status.LatestBlockHeight, info.Response.LastBlockHeight)
-		assert.True(t, strings.HasPrefix(info.Response.Data, "size"))
+		assert.True(t, strings.Contains(info.Response.Data, "size"))
 	}
 }
 
@@ -87,13 +86,13 @@ func TestGenesisAndValidators(t *testing.T) {
 		gval := gen.Genesis.Validators[0]
 
 		// get the current validators
-		vals, err := c.Validators()
+		vals, err := c.Validators(nil)
 		require.Nil(t, err, "%d: %+v", i, err)
 		require.Equal(t, 1, len(vals.Validators))
 		val := vals.Validators[0]
 
 		// make sure the current set is also the genesis set
-		assert.Equal(t, gval.Amount, val.VotingPower)
+		assert.Equal(t, gval.Power, val.VotingPower)
 		assert.Equal(t, gval.PubKey, val.PubKey)
 	}
 }
@@ -110,11 +109,12 @@ func TestAppCalls(t *testing.T) {
 		sh := s.LatestBlockHeight
 
 		// look for the future
-		_, err = c.Block(sh + 2)
+		h := sh + 2
+		_, err = c.Block(&h)
 		assert.NotNil(err) // no block yet
 
 		// write something
-		k, v, tx := merktest.MakeTxKV()
+		k, v, tx := MakeTxKV()
 		bres, err := c.BroadcastTxCommit(tx)
 		require.Nil(err, "%d: %+v", i, err)
 		require.True(bres.DeliverTx.Code.IsOK())
@@ -137,7 +137,7 @@ func TestAppCalls(t *testing.T) {
 		assert.EqualValues(tx, ptx.Tx)
 
 		// and we can even check the block is added
-		block, err := c.Block(apph)
+		block, err := c.Block(&apph)
 		require.Nil(err, "%d: %+v", i, err)
 		appHash := block.BlockMeta.Header.AppHash
 		assert.True(len(appHash) > 0)
@@ -158,14 +158,15 @@ func TestAppCalls(t *testing.T) {
 		}
 
 		// and get the corresponding commit with the same apphash
-		commit, err := c.Commit(apph)
+		commit, err := c.Commit(&apph)
 		require.Nil(err, "%d: %+v", i, err)
 		cappHash := commit.Header.AppHash
 		assert.Equal(appHash, cappHash)
 		assert.NotNil(commit.Commit)
 
 		// compare the commits (note Commit(2) has commit from Block(3))
-		commit2, err := c.Commit(apph - 1)
+		h = apph - 1
+		commit2, err := c.Commit(&h)
 		require.Nil(err, "%d: %+v", i, err)
 		assert.Equal(block.Block.LastCommit, commit2.Commit)
 
@@ -191,7 +192,7 @@ func TestBroadcastTxSync(t *testing.T) {
 	initMempoolSize := mempool.Size()
 
 	for i, c := range GetClients() {
-		_, _, tx := merktest.MakeTxKV()
+		_, _, tx := MakeTxKV()
 		bres, err := c.BroadcastTxSync(tx)
 		require.Nil(err, "%d: %+v", i, err)
 		require.True(bres.Code.IsOK())
@@ -209,7 +210,7 @@ func TestBroadcastTxCommit(t *testing.T) {
 
 	mempool := node.MempoolReactor().Mempool
 	for i, c := range GetClients() {
-		_, _, tx := merktest.MakeTxKV()
+		_, _, tx := MakeTxKV()
 		bres, err := c.BroadcastTxCommit(tx)
 		require.Nil(err, "%d: %+v", i, err)
 		require.True(bres.CheckTx.Code.IsOK())
@@ -224,7 +225,7 @@ func TestTx(t *testing.T) {
 
 	// first we broadcast a tx
 	c := getHTTPClient()
-	_, _, tx := merktest.MakeTxKV()
+	_, _, tx := MakeTxKV()
 	bres, err := c.BroadcastTxCommit(tx)
 	require.Nil(err, "%+v", err)
 
diff --git a/rpc/core/abci.go b/rpc/core/abci.go
index 21508caf7..06275a9e3 100644
--- a/rpc/core/abci.go
+++ b/rpc/core/abci.go
@@ -4,6 +4,7 @@ import (
 	abci "github.com/tendermint/abci/types"
 	data "github.com/tendermint/go-wire/data"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
+	"github.com/tendermint/tendermint/version"
 )
 
 // Query the application for some information.
@@ -86,7 +87,7 @@ func ABCIQuery(path string, data data.Bytes, prove bool) (*ctypes.ResultABCIQuer
 // }
 // ```
 func ABCIInfo() (*ctypes.ResultABCIInfo, error) {
-	resInfo, err := proxyAppQuery.InfoSync()
+	resInfo, err := proxyAppQuery.InfoSync(abci.RequestInfo{version.Version})
 	if err != nil {
 		return nil, err
 	}
diff --git a/rpc/core/blocks.go b/rpc/core/blocks.go
index 1f9e85422..17b27303f 100644
--- a/rpc/core/blocks.go
+++ b/rpc/core/blocks.go
@@ -85,6 +85,7 @@ func BlockchainInfo(minHeight, maxHeight int) (*ctypes.ResultBlockchainInfo, err
 }
 
 // Get block at a given height.
+// If no height is provided, it will fetch the latest block.
 //
 // ```shell
 // curl 'localhost:46657/block?height=10'
@@ -183,8 +184,16 @@ func BlockchainInfo(minHeight, maxHeight int) (*ctypes.ResultBlockchainInfo, err
 //   "jsonrpc": "2.0"
 // }
 // ```
-func Block(height int) (*ctypes.ResultBlock, error) {
-	if height == 0 {
+func Block(heightPtr *int) (*ctypes.ResultBlock, error) {
+	if heightPtr == nil {
+		height := blockStore.Height()
+		blockMeta := blockStore.LoadBlockMeta(height)
+		block := blockStore.LoadBlock(height)
+		return &ctypes.ResultBlock{blockMeta, block}, nil
+	}
+
+	height := *heightPtr
+	if height <= 0 {
 		return nil, fmt.Errorf("Height must be greater than 0")
 	}
 	if height > blockStore.Height() {
@@ -197,6 +206,7 @@ func Block(height int) (*ctypes.ResultBlock, error) {
 }
 
 // Get block commit at a given height.
+// If no height is provided, it will fetch the commit for the latest block.
 //
 // ```shell
 // curl 'localhost:46657/commit?height=11'
@@ -265,8 +275,16 @@ func Block(height int) (*ctypes.ResultBlock, error) {
 //   "jsonrpc": "2.0"
 // }
 // ```
-func Commit(height int) (*ctypes.ResultCommit, error) {
-	if height == 0 {
+func Commit(heightPtr *int) (*ctypes.ResultCommit, error) {
+	if heightPtr == nil {
+		height := blockStore.Height()
+		header := blockStore.LoadBlockMeta(height).Header
+		commit := blockStore.LoadSeenCommit(height)
+		return &ctypes.ResultCommit{header, commit, false}, nil
+	}
+
+	height := *heightPtr
+	if height <= 0 {
 		return nil, fmt.Errorf("Height must be greater than 0")
 	}
 	storeHeight := blockStore.Height()
diff --git a/rpc/core/consensus.go b/rpc/core/consensus.go
index fdce29e48..0429c8d45 100644
--- a/rpc/core/consensus.go
+++ b/rpc/core/consensus.go
@@ -7,7 +7,8 @@ import (
 	"github.com/tendermint/tendermint/types"
 )
 
-// Get current validators set along with a block height.
+// Get the validator set at the given block height.
+// If no height is provided, it will fetch the current validator set.
 //
 // ```shell
 // curl 'localhost:46657/validators'
@@ -41,9 +42,19 @@ import (
 // 	"jsonrpc": "2.0"
 // }
 // ```
-func Validators() (*ctypes.ResultValidators, error) {
-	blockHeight, validators := consensusState.GetValidators()
-	return &ctypes.ResultValidators{blockHeight, validators}, nil
+func Validators(heightPtr *int) (*ctypes.ResultValidators, error) {
+	if heightPtr == nil {
+		blockHeight, validators := consensusState.GetValidators()
+		return &ctypes.ResultValidators{blockHeight, validators}, nil
+	}
+
+	height := *heightPtr
+	state := consensusState.GetState()
+	validators, err := state.LoadValidators(height)
+	if err != nil {
+		return nil, err
+	}
+	return &ctypes.ResultValidators{height, validators.Validators}, nil
 }
 
 // Dump consensus state.
@@ -75,9 +86,9 @@ func DumpConsensusState() (*ctypes.ResultDumpConsensusState, error) {
 	peerRoundStates := []string{}
 	for _, peer := range p2pSwitch.Peers().List() {
 		// TODO: clean this up?
-		peerState := peer.Data.Get(types.PeerStateKey).(*cm.PeerState)
+		peerState := peer.Get(types.PeerStateKey).(*cm.PeerState)
 		peerRoundState := peerState.GetRoundState()
-		peerRoundStateStr := peer.Key + ":" + string(wire.JSONBytes(peerRoundState))
+		peerRoundStateStr := peer.Key() + ":" + string(wire.JSONBytes(peerRoundState))
 		peerRoundStates = append(peerRoundStates, peerRoundStateStr)
 	}
 	return &ctypes.ResultDumpConsensusState{roundState.String(), peerRoundStates}, nil
diff --git a/rpc/core/events.go b/rpc/core/events.go
index 4671d3417..00fd9a08c 100644
--- a/rpc/core/events.go
+++ b/rpc/core/events.go
@@ -2,7 +2,7 @@ package core
 
 import (
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
-	"github.com/tendermint/tendermint/rpc/lib/types"
+	rpctypes "github.com/tendermint/tendermint/rpc/lib/types"
 	"github.com/tendermint/tendermint/types"
 )
 
@@ -39,7 +39,7 @@ func Subscribe(wsCtx rpctypes.WSRPCContext, event string) (*ctypes.ResultSubscri
 		// NOTE: EventSwitch callbacks must be nonblocking
 		// NOTE: RPCResponses of subscribed events have id suffix "#event"
 		tmResult := &ctypes.ResultEvent{event, msg}
-		wsCtx.TryWriteRPCResponse(rpctypes.NewRPCResponse(wsCtx.Request.ID+"#event", tmResult, ""))
+		wsCtx.TryWriteRPCResponse(rpctypes.NewRPCSuccessResponse(wsCtx.Request.ID+"#event", tmResult))
 	})
 	return &ctypes.ResultSubscribe{}, nil
 }
diff --git a/rpc/core/net.go b/rpc/core/net.go
index 6c2dc587e..b3f1c7ce5 100644
--- a/rpc/core/net.go
+++ b/rpc/core/net.go
@@ -42,9 +42,9 @@ func NetInfo() (*ctypes.ResultNetInfo, error) {
 	peers := []ctypes.Peer{}
 	for _, peer := range p2pSwitch.Peers().List() {
 		peers = append(peers, ctypes.Peer{
-			NodeInfo:         *peer.NodeInfo,
+			NodeInfo:         *peer.NodeInfo(),
 			IsOutbound:       peer.IsOutbound(),
-			ConnectionStatus: peer.Connection().Status(),
+			ConnectionStatus: peer.Status(),
 		})
 	}
 	return &ctypes.ResultNetInfo{
@@ -90,7 +90,7 @@ func UnsafeDialSeeds(seeds []string) (*ctypes.ResultDialSeeds, error) {
 // 			"validators": [
 // 				{
 // 					"name": "",
-// 					"amount": 10,
+// 					"power": 10,
 // 					"pub_key": {
 // 						"data": "68DFDA7E50F82946E7E8546BED37944A422CD1B831E70DF66BA3B8430593944D",
 // 						"type": "ed25519"
diff --git a/rpc/core/pipe.go b/rpc/core/pipe.go
index 92e5746a6..86c6c65e1 100644
--- a/rpc/core/pipe.go
+++ b/rpc/core/pipe.go
@@ -2,18 +2,21 @@ package core
 
 import (
 	crypto "github.com/tendermint/go-crypto"
+	"github.com/tendermint/tmlibs/log"
+
 	"github.com/tendermint/tendermint/consensus"
 	p2p "github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/proxy"
+	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/state/txindex"
 	"github.com/tendermint/tendermint/types"
-	"github.com/tendermint/tmlibs/log"
 )
 
 //----------------------------------------------
 // These interfaces are used by RPC and must be thread safe
 
 type Consensus interface {
+	GetState() *sm.State
 	GetValidators() (int, []*types.Validator)
 	GetRoundState() *consensus.RoundState
 }
diff --git a/rpc/core/routes.go b/rpc/core/routes.go
index 795acde9b..485f7a00f 100644
--- a/rpc/core/routes.go
+++ b/rpc/core/routes.go
@@ -18,7 +18,7 @@ var Routes = map[string]*rpc.RPCFunc{
 	"block":                rpc.NewRPCFunc(Block, "height"),
 	"commit":               rpc.NewRPCFunc(Commit, "height"),
 	"tx":                   rpc.NewRPCFunc(Tx, "hash,prove"),
-	"validators":           rpc.NewRPCFunc(Validators, ""),
+	"validators":           rpc.NewRPCFunc(Validators, "height"),
 	"dump_consensus_state": rpc.NewRPCFunc(DumpConsensusState, ""),
 	"unconfirmed_txs":      rpc.NewRPCFunc(UnconfirmedTxs, ""),
 	"num_unconfirmed_txs":  rpc.NewRPCFunc(NumUnconfirmedTxs, ""),
diff --git a/rpc/lib/client/http_client.go b/rpc/lib/client/http_client.go
index 755c3e79c..1fbaedfae 100644
--- a/rpc/lib/client/http_client.go
+++ b/rpc/lib/client/http_client.go
@@ -75,7 +75,7 @@ func NewJSONRPCClient(remote string) *JSONRPCClient {
 }
 
 func (c *JSONRPCClient) Call(method string, params map[string]interface{}, result interface{}) (interface{}, error) {
-	request, err := types.MapToRequest("", method, params)
+	request, err := types.MapToRequest("jsonrpc-client", method, params)
 	if err != nil {
 		return nil, err
 	}
@@ -146,9 +146,8 @@ func unmarshalResponseBytes(responseBytes []byte, result interface{}) (interface
 	if err != nil {
 		return nil, errors.Errorf("Error unmarshalling rpc response: %v", err)
 	}
-	errorStr := response.Error
-	if errorStr != "" {
-		return nil, errors.Errorf("Response error: %v", errorStr)
+	if response.Error != nil {
+		return nil, errors.Errorf("Response error: %v", response.Error.Message)
 	}
 	// unmarshal the RawMessage into the result
 	err = json.Unmarshal(*response.Result, result)
diff --git a/rpc/lib/client/ws_client.go b/rpc/lib/client/ws_client.go
index f56c45e99..1407073ae 100644
--- a/rpc/lib/client/ws_client.go
+++ b/rpc/lib/client/ws_client.go
@@ -195,7 +195,7 @@ func (c *WSClient) Send(ctx context.Context, request types.RPCRequest) error {
 
 // Call the given method. See Send description.
 func (c *WSClient) Call(ctx context.Context, method string, params map[string]interface{}) error {
-	request, err := types.MapToRequest("", method, params)
+	request, err := types.MapToRequest("ws-client", method, params)
 	if err != nil {
 		return err
 	}
@@ -205,7 +205,7 @@ func (c *WSClient) Call(ctx context.Context, method string, params map[string]in
 // CallWithArrayParams the given method with params in a form of array. See
 // Send description.
 func (c *WSClient) CallWithArrayParams(ctx context.Context, method string, params []interface{}) error {
-	request, err := types.ArrayToRequest("", method, params)
+	request, err := types.ArrayToRequest("ws-client", method, params)
 	if err != nil {
 		return err
 	}
@@ -422,8 +422,8 @@ func (c *WSClient) readRoutine() {
 			c.ErrorsCh <- err
 			continue
 		}
-		if response.Error != "" {
-			c.ErrorsCh <- errors.Errorf(response.Error)
+		if response.Error != nil {
+			c.ErrorsCh <- errors.New(response.Error.Message)
 			continue
 		}
 		c.Logger.Info("got response", "resp", response.Result)
diff --git a/rpc/lib/server/handlers.go b/rpc/lib/server/handlers.go
index 3b81567e4..0fafd2a84 100644
--- a/rpc/lib/server/handlers.go
+++ b/rpc/lib/server/handlers.go
@@ -110,35 +110,36 @@ func makeJSONRPCHandler(funcMap map[string]*RPCFunc, logger log.Logger) http.Han
 		var request types.RPCRequest
 		err := json.Unmarshal(b, &request)
 		if err != nil {
-			WriteRPCResponseHTTPError(w, http.StatusBadRequest, types.NewRPCResponse("", nil, fmt.Sprintf("Error unmarshalling request: %v", err.Error())))
+			WriteRPCResponseHTTP(w, types.RPCParseError("", errors.Wrap(err, "Error unmarshalling request")))
 			return
 		}
-		if len(r.URL.Path) > 1 {
-			WriteRPCResponseHTTPError(w, http.StatusNotFound, types.NewRPCResponse(request.ID, nil, fmt.Sprintf("Invalid JSONRPC endpoint %s", r.URL.Path)))
+		// A Notification is a Request object without an "id" member.
+		// The Server MUST NOT reply to a Notification, including those that are within a batch request.
+		if request.ID == "" {
 			return
 		}
-		rpcFunc := funcMap[request.Method]
-		if rpcFunc == nil {
-			WriteRPCResponseHTTPError(w, http.StatusNotFound, types.NewRPCResponse(request.ID, nil, "RPC method unknown: "+request.Method))
+		if len(r.URL.Path) > 1 {
+			WriteRPCResponseHTTP(w, types.RPCInvalidRequestError(request.ID, errors.Errorf("Path %s is invalid", r.URL.Path)))
 			return
 		}
-		if rpcFunc.ws {
-			WriteRPCResponseHTTPError(w, http.StatusMethodNotAllowed, types.NewRPCResponse(request.ID, nil, "RPC method is only for websockets: "+request.Method))
+		rpcFunc := funcMap[request.Method]
+		if rpcFunc == nil || rpcFunc.ws {
+			WriteRPCResponseHTTP(w, types.RPCMethodNotFoundError(request.ID))
 			return
 		}
 		args, err := jsonParamsToArgsRPC(rpcFunc, request.Params)
 		if err != nil {
-			WriteRPCResponseHTTPError(w, http.StatusBadRequest, types.NewRPCResponse(request.ID, nil, fmt.Sprintf("Error converting json params to arguments: %v", err.Error())))
+			WriteRPCResponseHTTP(w, types.RPCInvalidParamsError(request.ID, errors.Wrap(err, "Error converting json params to arguments")))
 			return
 		}
 		returns := rpcFunc.f.Call(args)
 		logger.Info("HTTPJSONRPC", "method", request.Method, "args", args, "returns", returns)
 		result, err := unreflectResult(returns)
 		if err != nil {
-			WriteRPCResponseHTTPError(w, http.StatusInternalServerError, types.NewRPCResponse(request.ID, result, err.Error()))
+			WriteRPCResponseHTTP(w, types.RPCInternalError(request.ID, err))
 			return
 		}
-		WriteRPCResponseHTTP(w, types.NewRPCResponse(request.ID, result, ""))
+		WriteRPCResponseHTTP(w, types.NewRPCSuccessResponse(request.ID, result))
 	}
 }
 
@@ -229,7 +230,7 @@ func makeHTTPHandler(rpcFunc *RPCFunc, logger log.Logger) func(http.ResponseWrit
 	// Exception for websocket endpoints
 	if rpcFunc.ws {
 		return func(w http.ResponseWriter, r *http.Request) {
-			WriteRPCResponseHTTPError(w, http.StatusMethodNotAllowed, types.NewRPCResponse("", nil, "This RPC method is only for websockets"))
+			WriteRPCResponseHTTP(w, types.RPCMethodNotFoundError(""))
 		}
 	}
 	// All other endpoints
@@ -237,17 +238,17 @@ func makeHTTPHandler(rpcFunc *RPCFunc, logger log.Logger) func(http.ResponseWrit
 		logger.Debug("HTTP HANDLER", "req", r)
 		args, err := httpParamsToArgs(rpcFunc, r)
 		if err != nil {
-			WriteRPCResponseHTTPError(w, http.StatusBadRequest, types.NewRPCResponse("", nil, fmt.Sprintf("Error converting http params to args: %v", err.Error())))
+			WriteRPCResponseHTTP(w, types.RPCInvalidParamsError("", errors.Wrap(err, "Error converting http params to arguments")))
 			return
 		}
 		returns := rpcFunc.f.Call(args)
 		logger.Info("HTTPRestRPC", "method", r.URL.Path, "args", args, "returns", returns)
 		result, err := unreflectResult(returns)
 		if err != nil {
-			WriteRPCResponseHTTPError(w, http.StatusInternalServerError, types.NewRPCResponse("", nil, err.Error()))
+			WriteRPCResponseHTTP(w, types.RPCInternalError("", err))
 			return
 		}
-		WriteRPCResponseHTTP(w, types.NewRPCResponse("", result, ""))
+		WriteRPCResponseHTTP(w, types.NewRPCSuccessResponse("", result))
 	}
 }
 
@@ -509,8 +510,13 @@ func (wsc *wsConnection) readRoutine() {
 			var request types.RPCRequest
 			err = json.Unmarshal(in, &request)
 			if err != nil {
-				errStr := fmt.Sprintf("Error unmarshaling data: %s", err.Error())
-				wsc.WriteRPCResponse(types.NewRPCResponse(request.ID, nil, errStr))
+				wsc.WriteRPCResponse(types.RPCParseError("", errors.Wrap(err, "Error unmarshaling request")))
+				continue
+			}
+
+			// A Notification is a Request object without an "id" member.
+			// The Server MUST NOT reply to a Notification, including those that are within a batch request.
+			if request.ID == "" {
 				continue
 			}
 
@@ -518,7 +524,7 @@ func (wsc *wsConnection) readRoutine() {
 
 			rpcFunc := wsc.funcMap[request.Method]
 			if rpcFunc == nil {
-				wsc.WriteRPCResponse(types.NewRPCResponse(request.ID, nil, "RPC method unknown: "+request.Method))
+				wsc.WriteRPCResponse(types.RPCMethodNotFoundError(request.ID))
 				continue
 			}
 			var args []reflect.Value
@@ -529,7 +535,7 @@ func (wsc *wsConnection) readRoutine() {
 				args, err = jsonParamsToArgsRPC(rpcFunc, request.Params)
 			}
 			if err != nil {
-				wsc.WriteRPCResponse(types.NewRPCResponse(request.ID, nil, err.Error()))
+				wsc.WriteRPCResponse(types.RPCInternalError(request.ID, errors.Wrap(err, "Error converting json params to arguments")))
 				continue
 			}
 			returns := rpcFunc.f.Call(args)
@@ -539,10 +545,10 @@ func (wsc *wsConnection) readRoutine() {
 
 			result, err := unreflectResult(returns)
 			if err != nil {
-				wsc.WriteRPCResponse(types.NewRPCResponse(request.ID, nil, err.Error()))
+				wsc.WriteRPCResponse(types.RPCInternalError(request.ID, err))
 				continue
 			} else {
-				wsc.WriteRPCResponse(types.NewRPCResponse(request.ID, result, ""))
+				wsc.WriteRPCResponse(types.NewRPCSuccessResponse(request.ID, result))
 				continue
 			}
 
diff --git a/rpc/lib/server/http_server.go b/rpc/lib/server/http_server.go
index 270321b4b..7623337db 100644
--- a/rpc/lib/server/http_server.go
+++ b/rpc/lib/server/http_server.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
+
 	types "github.com/tendermint/tendermint/rpc/lib/types"
 	"github.com/tendermint/tmlibs/log"
 )
@@ -99,7 +100,7 @@ func RecoverAndLogHandler(handler http.Handler, logger log.Logger) http.Handler
 					// For the rest,
 					logger.Error("Panic in RPC HTTP handler", "err", e, "stack", string(debug.Stack()))
 					rww.WriteHeader(http.StatusInternalServerError)
-					WriteRPCResponseHTTP(rww, types.NewRPCResponse("", nil, fmt.Sprintf("Internal Server Error: %v", e)))
+					WriteRPCResponseHTTP(rww, types.RPCInternalError("", e.(error)))
 				}
 			}
 
diff --git a/rpc/lib/types/types.go b/rpc/lib/types/types.go
index f4a2cede0..4928db514 100644
--- a/rpc/lib/types/types.go
+++ b/rpc/lib/types/types.go
@@ -5,9 +5,14 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/pkg/errors"
+
 	events "github.com/tendermint/tmlibs/events"
 )
 
+//----------------------------------------
+// REQUEST
+
 type RPCRequest struct {
 	JSONRPC string           `json:"jsonrpc"`
 	ID      string           `json:"id"`
@@ -47,42 +52,77 @@ func ArrayToRequest(id string, method string, params []interface{}) (RPCRequest,
 }
 
 //----------------------------------------
+// RESPONSE
+
+type RPCError struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+	Data    string `json:"data,omitempty"`
+}
 
 type RPCResponse struct {
 	JSONRPC string           `json:"jsonrpc"`
 	ID      string           `json:"id"`
-	Result  *json.RawMessage `json:"result"`
-	Error   string           `json:"error"`
+	Result  *json.RawMessage `json:"result,omitempty"`
+	Error   *RPCError        `json:"error,omitempty"`
 }
 
-func NewRPCResponse(id string, res interface{}, err string) RPCResponse {
+func NewRPCSuccessResponse(id string, res interface{}) RPCResponse {
 	var raw *json.RawMessage
+
 	if res != nil {
 		var js []byte
-		js, err2 := json.Marshal(res)
-		if err2 == nil {
-			rawMsg := json.RawMessage(js)
-			raw = &rawMsg
-		} else {
-			err = err2.Error()
+		js, err := json.Marshal(res)
+		if err != nil {
+			return RPCInternalError(id, errors.Wrap(err, "Error marshalling response"))
 		}
+		rawMsg := json.RawMessage(js)
+		raw = &rawMsg
 	}
+
+	return RPCResponse{JSONRPC: "2.0", ID: id, Result: raw}
+}
+
+func NewRPCErrorResponse(id string, code int, msg string, data string) RPCResponse {
 	return RPCResponse{
 		JSONRPC: "2.0",
 		ID:      id,
-		Result:  raw,
-		Error:   err,
+		Error:   &RPCError{Code: code, Message: msg, Data: data},
 	}
 }
 
 func (resp RPCResponse) String() string {
-	if resp.Error == "" {
+	if resp.Error == nil {
 		return fmt.Sprintf("[%s %v]", resp.ID, resp.Result)
 	} else {
 		return fmt.Sprintf("[%s %s]", resp.ID, resp.Error)
 	}
 }
 
+func RPCParseError(id string, err error) RPCResponse {
+	return NewRPCErrorResponse(id, -32700, "Parse error. Invalid JSON", err.Error())
+}
+
+func RPCInvalidRequestError(id string, err error) RPCResponse {
+	return NewRPCErrorResponse(id, -32600, "Invalid Request", err.Error())
+}
+
+func RPCMethodNotFoundError(id string) RPCResponse {
+	return NewRPCErrorResponse(id, -32601, "Method not found", "")
+}
+
+func RPCInvalidParamsError(id string, err error) RPCResponse {
+	return NewRPCErrorResponse(id, -32602, "Invalid params", err.Error())
+}
+
+func RPCInternalError(id string, err error) RPCResponse {
+	return NewRPCErrorResponse(id, -32603, "Internal error", err.Error())
+}
+
+func RPCServerError(id string, err error) RPCResponse {
+	return NewRPCErrorResponse(id, -32000, "Server error", err.Error())
+}
+
 //----------------------------------------
 
 // *wsConnection implements this interface.
@@ -100,10 +140,11 @@ type WSRPCContext struct {
 }
 
 //----------------------------------------
-// sockets
+// SOCKETS
 //
 // Determine if its a unix or tcp socket.
 // If tcp, must specify the port; `0.0.0.0` will return incorrectly as "unix" since there's no port
+// TODO: deprecate
 func SocketType(listenAddr string) string {
 	socketType := "unix"
 	if len(strings.Split(listenAddr, ":")) >= 2 {
diff --git a/rpc/lib/types/types_test.go b/rpc/lib/types/types_test.go
new file mode 100644
index 000000000..bab42124a
--- /dev/null
+++ b/rpc/lib/types/types_test.go
@@ -0,0 +1,32 @@
+package rpctypes
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/assert"
+)
+
+type SampleResult struct {
+	Value string
+}
+
+func TestResponses(t *testing.T) {
+	assert := assert.New(t)
+
+	a := NewRPCSuccessResponse("1", &SampleResult{"hello"})
+	b, _ := json.Marshal(a)
+	s := `{"jsonrpc":"2.0","id":"1","result":{"Value":"hello"}}`
+	assert.Equal(string(s), string(b))
+
+	d := RPCParseError("1", errors.New("Hello world"))
+	e, _ := json.Marshal(d)
+	f := `{"jsonrpc":"2.0","id":"1","error":{"code":-32700,"message":"Parse error. Invalid JSON","data":"Hello world"}}`
+	assert.Equal(string(f), string(e))
+
+	g := RPCMethodNotFoundError("2")
+	h, _ := json.Marshal(g)
+	i := `{"jsonrpc":"2.0","id":"2","error":{"code":-32601,"message":"Method not found"}}`
+	assert.Equal(string(h), string(i))
+}
diff --git a/rpc/test/helpers.go b/rpc/test/helpers.go
index 14da15c94..55e27f5b8 100644
--- a/rpc/test/helpers.go
+++ b/rpc/test/helpers.go
@@ -79,8 +79,13 @@ func NewTendermint(app abci.Application) *nm.Node {
 	logger := log.NewTMLogger(log.NewSyncWriter(os.Stdout))
 	logger = log.NewFilter(logger, log.AllowError())
 	privValidatorFile := config.PrivValidatorFile()
-	privValidator := types.LoadOrGenPrivValidator(privValidatorFile, logger)
+	privValidator := types.LoadOrGenPrivValidatorFS(privValidatorFile)
 	papp := proxy.NewLocalClientCreator(app)
-	node := nm.NewNode(config, privValidator, papp, logger)
+	node, err := nm.NewNode(config, privValidator, papp,
+		nm.DefaultGenesisDocProviderFunc(config),
+		nm.DefaultDBProvider, logger)
+	if err != nil {
+		panic(err)
+	}
 	return node
 }
diff --git a/state/errors.go b/state/errors.go
index 50c5a2c04..4a87384a0 100644
--- a/state/errors.go
+++ b/state/errors.go
@@ -33,6 +33,10 @@ type (
 		Got      *State
 		Expected *State
 	}
+
+	ErrNoValSetForHeight struct {
+		Height int
+	}
 )
 
 func (e ErrUnknownBlock) Error() string {
@@ -53,3 +57,7 @@ func (e ErrLastStateMismatch) Error() string {
 func (e ErrStateMismatch) Error() string {
 	return cmn.Fmt("State after replay does not match saved state. Got ----\n%v\nExpected ----\n%v\n", e.Got, e.Expected)
 }
+
+func (e ErrNoValSetForHeight) Error() string {
+	return cmn.Fmt("Could not find validator set for height #%d", e.Height)
+}
diff --git a/state/execution.go b/state/execution.go
index 9e4a5fb29..b917bfbe8 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -83,7 +83,10 @@ func execBlockOnProxyApp(eventCache types.Fireable, proxyAppConn proxy.AppConnCo
 	proxyAppConn.SetResponseCallback(proxyCb)
 
 	// Begin block
-	err := proxyAppConn.BeginBlockSync(block.Hash(), types.TM2PB.Header(block.Header))
+	err := proxyAppConn.BeginBlockSync(abci.RequestBeginBlock{
+		block.Hash(),
+		types.TM2PB.Header(block.Header),
+	})
 	if err != nil {
 		logger.Error("Error in proxyAppConn.BeginBlock", "err", err)
 		return nil, err
@@ -239,7 +242,7 @@ func (s *State) ApplyBlock(eventCache types.Fireable, proxyAppConn proxy.AppConn
 
 	fail.Fail() // XXX
 
-	// save the state
+	// save the state and the validators
 	s.Save()
 
 	return nil
diff --git a/state/execution_test.go b/state/execution_test.go
index 3ebc05d37..2987667c5 100644
--- a/state/execution_test.go
+++ b/state/execution_test.go
@@ -55,13 +55,14 @@ func makeTxs(blockNum int) (txs []types.Tx) {
 }
 
 func state() *State {
-	return MakeGenesisState(dbm.NewMemDB(), &types.GenesisDoc{
+	s, _ := MakeGenesisState(dbm.NewMemDB(), &types.GenesisDoc{
 		ChainID: chainID,
 		Validators: []types.GenesisValidator{
 			types.GenesisValidator{privKey.PubKey(), 10000, "test"},
 		},
 		AppHash: nil,
 	})
+	return s
 }
 
 func makeBlock(num int, state *State) *types.Block {
diff --git a/state/state.go b/state/state.go
index 21ad92776..53ec8cc03 100644
--- a/state/state.go
+++ b/state/state.go
@@ -2,6 +2,7 @@ package state
 
 import (
 	"bytes"
+	"fmt"
 	"io/ioutil"
 	"sync"
 	"time"
@@ -22,6 +23,10 @@ var (
 	abciResponsesKey = []byte("abciResponsesKey")
 )
 
+func calcValidatorsKey(height int) []byte {
+	return []byte(cmn.Fmt("validatorsKey:%v", height))
+}
+
 //-----------------------------------------------------------------------------
 
 // State represents the latest committed state of the Tendermint consensus,
@@ -37,21 +42,45 @@ type State struct {
 	GenesisDoc *types.GenesisDoc
 	ChainID    string
 
-	// updated at end of SetBlockAndValidators
-	LastBlockHeight int // Genesis state has this set to 0.  So, Block(H=0) does not exist.
+	// These fields are updated by SetBlockAndValidators.
+	// LastBlockHeight=0 at genesis (ie. block(H=0) does not exist)
+	// LastValidators is used to validate block.LastCommit.
+	LastBlockHeight int
 	LastBlockID     types.BlockID
 	LastBlockTime   time.Time
 	Validators      *types.ValidatorSet
-	LastValidators  *types.ValidatorSet // block.LastCommit validated against this
+	LastValidators  *types.ValidatorSet
 
 	// AppHash is updated after Commit
 	AppHash []byte
 
-	TxIndexer txindex.TxIndexer `json:"-"` // Transaction indexer.
+	TxIndexer txindex.TxIndexer `json:"-"` // Transaction indexer
+
+	// When a block returns a validator set change via EndBlock,
+	// the change only applies to the next block.
+	// So, if s.LastBlockHeight causes a valset change,
+	// we set s.LastHeightValidatorsChanged = s.LastBlockHeight + 1
+	LastHeightValidatorsChanged int
 
 	logger log.Logger
 }
 
+// GetState loads the most recent state from the database,
+// or creates a new one from the given genesisFile and persists the result
+// to the database.
+func GetState(stateDB dbm.DB, genesisFile string) (*State, error) {
+	var err error
+	state := LoadState(stateDB)
+	if state == nil {
+		state, err = MakeGenesisStateFromFile(stateDB, genesisFile)
+		if err != nil {
+			return nil, err
+		}
+		state.Save()
+	}
+	return state, nil
+}
+
 // LoadState loads the State from the database.
 func LoadState(db dbm.DB) *State {
 	return loadState(db, stateKey)
@@ -71,6 +100,7 @@ func loadState(db dbm.DB, key []byte) *State {
 		}
 		// TODO: ensure that buf is completely read.
 	}
+
 	return s
 }
 
@@ -82,17 +112,18 @@ func (s *State) SetLogger(l log.Logger) {
 // Copy makes a copy of the State for mutating.
 func (s *State) Copy() *State {
 	return &State{
-		db:              s.db,
-		GenesisDoc:      s.GenesisDoc,
-		ChainID:         s.ChainID,
-		LastBlockHeight: s.LastBlockHeight,
-		LastBlockID:     s.LastBlockID,
-		LastBlockTime:   s.LastBlockTime,
-		Validators:      s.Validators.Copy(),
-		LastValidators:  s.LastValidators.Copy(),
-		AppHash:         s.AppHash,
-		TxIndexer:       s.TxIndexer, // pointer here, not value
-		logger:          s.logger,
+		db:                          s.db,
+		GenesisDoc:                  s.GenesisDoc,
+		ChainID:                     s.ChainID,
+		LastBlockHeight:             s.LastBlockHeight,
+		LastBlockID:                 s.LastBlockID,
+		LastBlockTime:               s.LastBlockTime,
+		Validators:                  s.Validators.Copy(),
+		LastValidators:              s.LastValidators.Copy(),
+		AppHash:                     s.AppHash,
+		TxIndexer:                   s.TxIndexer, // pointer here, not value
+		LastHeightValidatorsChanged: s.LastHeightValidatorsChanged,
+		logger: s.logger,
 	}
 }
 
@@ -100,6 +131,7 @@ func (s *State) Copy() *State {
 func (s *State) Save() {
 	s.mtx.Lock()
 	defer s.mtx.Unlock()
+	s.saveValidatorsInfo()
 	s.db.SetSync(stateKey, s.Bytes())
 }
 
@@ -126,6 +158,57 @@ func (s *State) LoadABCIResponses() *ABCIResponses {
 	return abciResponses
 }
 
+// LoadValidators loads the ValidatorSet for a given height.
+func (s *State) LoadValidators(height int) (*types.ValidatorSet, error) {
+	v := s.loadValidators(height)
+	if v == nil {
+		return nil, ErrNoValSetForHeight{height}
+	}
+
+	if v.ValidatorSet == nil {
+		v = s.loadValidators(v.LastHeightChanged)
+		if v == nil {
+			cmn.PanicSanity(fmt.Sprintf(`Couldn't find validators at 
+			height %d as last changed from height %d`, v.LastHeightChanged, height))
+		}
+	}
+
+	return v.ValidatorSet, nil
+}
+
+func (s *State) loadValidators(height int) *ValidatorsInfo {
+	buf := s.db.Get(calcValidatorsKey(height))
+	if len(buf) == 0 {
+		return nil
+	}
+
+	v := new(ValidatorsInfo)
+	r, n, err := bytes.NewReader(buf), new(int), new(error)
+	wire.ReadBinaryPtr(v, r, 0, n, err)
+	if *err != nil {
+		// DATA HAS BEEN CORRUPTED OR THE SPEC HAS CHANGED
+		cmn.Exit(cmn.Fmt("LoadValidators: Data has been corrupted or its spec has changed: %v\n", *err))
+	}
+	// TODO: ensure that buf is completely read.
+	return v
+}
+
+// saveValidatorsInfo persists the validator set for the next block to disk.
+// It should be called from s.Save(), right before the state itself is persisted.
+// If the validator set did not change after processing the latest block,
+// only the last height for which the validators changed is persisted.
+func (s *State) saveValidatorsInfo() {
+	changeHeight := s.LastHeightValidatorsChanged
+	nextHeight := s.LastBlockHeight + 1
+	vi := &ValidatorsInfo{
+		LastHeightChanged: changeHeight,
+	}
+	if changeHeight == nextHeight {
+		vi.ValidatorSet = s.Validators
+	}
+	s.db.SetSync(calcValidatorsKey(nextHeight), vi.Bytes())
+}
+
 // Equals returns true if the States are identical.
 func (s *State) Equals(s2 *State) bool {
 	return bytes.Equal(s.Bytes(), s2.Bytes())
@@ -144,17 +227,23 @@ func (s *State) SetBlockAndValidators(header *types.Header, blockPartsHeader typ
 	prevValSet := s.Validators.Copy()
 	nextValSet := prevValSet.Copy()
 
-	err := updateValidators(nextValSet, abciResponses.EndBlock.Diffs)
-	if err != nil {
-		s.logger.Error("Error changing validator set", "err", err)
-		// TODO: err or carry on?
+	// update the validator set with the latest abciResponses
+	if len(abciResponses.EndBlock.Diffs) > 0 {
+		err := updateValidators(nextValSet, abciResponses.EndBlock.Diffs)
+		if err != nil {
+			s.logger.Error("Error changing validator set", "err", err)
+			// TODO: err or carry on?
+		}
+		// change results from this height but only applies to the next height
+		s.LastHeightValidatorsChanged = header.Height + 1
 	}
 
 	// Update validator accums and set state variables
 	nextValSet.IncrementAccum(1)
 
 	s.setBlockAndValidators(header.Height,
-		types.BlockID{header.Hash(), blockPartsHeader}, header.Time,
+		types.BlockID{header.Hash(), blockPartsHeader},
+		header.Time,
 		prevValSet, nextValSet)
 
 }
@@ -175,20 +264,15 @@ func (s *State) GetValidators() (*types.ValidatorSet, *types.ValidatorSet) {
 	return s.LastValidators, s.Validators
 }
 
-// GetState loads the most recent state from the database,
-// or creates a new one from the given genesisFile and persists the result
-// to the database.
-func GetState(stateDB dbm.DB, genesisFile string) *State {
-	state := LoadState(stateDB)
-	if state == nil {
-		state = MakeGenesisStateFromFile(stateDB, genesisFile)
-		state.Save()
-	}
-
-	return state
+// Params returns the consensus parameters used for
+// validating blocks
+func (s *State) Params() types.ConsensusParams {
+	// TODO: this should move into the State proper
+	// when we allow the app to change it
+	return *s.GenesisDoc.ConsensusParams
 }
 
-//--------------------------------------------------
+//------------------------------------------------------------------------
 
 // ABCIResponses retains the responses of the various ABCI calls during block processing.
 // It is persisted to disk before calling Commit.
@@ -216,33 +300,53 @@ func (a *ABCIResponses) Bytes() []byte {
 }
 
 //-----------------------------------------------------------------------------
+
+// ValidatorsInfo represents the latest validator set, or the last time it changed
+type ValidatorsInfo struct {
+	ValidatorSet      *types.ValidatorSet
+	LastHeightChanged int
+}
+
+// Bytes serializes the ValidatorsInfo using go-wire
+func (vi *ValidatorsInfo) Bytes() []byte {
+	return wire.BinaryBytes(*vi)
+}
+
+//------------------------------------------------------------------------
 // Genesis
 
-// MakeGenesisStateFromFile reads and unmarshals state from the given file.
+// MakeGenesisStateFromFile reads and unmarshals state from the given
+// file.
 //
 // Used during replay and in tests.
-func MakeGenesisStateFromFile(db dbm.DB, genDocFile string) *State {
+func MakeGenesisStateFromFile(db dbm.DB, genDocFile string) (*State, error) {
+	genDoc, err := MakeGenesisDocFromFile(genDocFile)
+	if err != nil {
+		return nil, err
+	}
+	return MakeGenesisState(db, genDoc)
+}
+
+// MakeGenesisDocFromFile reads and unmarshals genesis doc from the given file.
+func MakeGenesisDocFromFile(genDocFile string) (*types.GenesisDoc, error) {
 	genDocJSON, err := ioutil.ReadFile(genDocFile)
 	if err != nil {
-		cmn.Exit(cmn.Fmt("Couldn't read GenesisDoc file: %v", err))
+		return nil, fmt.Errorf("Couldn't read GenesisDoc file: %v", err)
 	}
 	genDoc, err := types.GenesisDocFromJSON(genDocJSON)
 	if err != nil {
-		cmn.Exit(cmn.Fmt("Error reading GenesisDoc: %v", err))
+		return nil, fmt.Errorf("Error reading GenesisDoc: %v", err)
 	}
-	return MakeGenesisState(db, genDoc)
+	return genDoc, nil
 }
 
 // MakeGenesisState creates state from types.GenesisDoc.
 //
 // Used in tests.
-func MakeGenesisState(db dbm.DB, genDoc *types.GenesisDoc) *State {
-	if len(genDoc.Validators) == 0 {
-		cmn.Exit(cmn.Fmt("The genesis file has no validators"))
-	}
-
-	if genDoc.GenesisTime.IsZero() {
-		genDoc.GenesisTime = time.Now()
+func MakeGenesisState(db dbm.DB, genDoc *types.GenesisDoc) (*State, error) {
+	err := genDoc.ValidateAndComplete()
+	if err != nil {
+		return nil, fmt.Errorf("Error in genesis file: %v", err)
 	}
 
 	// Make validators slice
@@ -255,20 +359,21 @@ func MakeGenesisState(db dbm.DB, genDoc *types.GenesisDoc) *State {
 		validators[i] = &types.Validator{
 			Address:     address,
 			PubKey:      pubKey,
-			VotingPower: val.Amount,
+			VotingPower: val.Power,
 		}
 	}
 
 	return &State{
-		db:              db,
-		GenesisDoc:      genDoc,
-		ChainID:         genDoc.ChainID,
-		LastBlockHeight: 0,
-		LastBlockID:     types.BlockID{},
-		LastBlockTime:   genDoc.GenesisTime,
-		Validators:      types.NewValidatorSet(validators),
-		LastValidators:  types.NewValidatorSet(nil),
-		AppHash:         genDoc.AppHash,
-		TxIndexer:       &null.TxIndex{}, // we do not need indexer during replay and in tests
-	}
+		db:                          db,
+		GenesisDoc:                  genDoc,
+		ChainID:                     genDoc.ChainID,
+		LastBlockHeight:             0,
+		LastBlockID:                 types.BlockID{},
+		LastBlockTime:               genDoc.GenesisTime,
+		Validators:                  types.NewValidatorSet(validators),
+		LastValidators:              types.NewValidatorSet(nil),
+		AppHash:                     genDoc.AppHash,
+		TxIndexer:                   &null.TxIndex{}, // we do not need indexer during replay and in tests
+		LastHeightValidatorsChanged: 1,
+	}, nil
 }
diff --git a/state/state_test.go b/state/state_test.go
index e97c3289a..2c19a4164 100644
--- a/state/state_test.go
+++ b/state/state_test.go
@@ -1,63 +1,69 @@
 package state
 
 import (
+	"bytes"
 	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+
 	abci "github.com/tendermint/abci/types"
+
 	crypto "github.com/tendermint/go-crypto"
-	cfg "github.com/tendermint/tendermint/config"
+
+	cmn "github.com/tendermint/tmlibs/common"
 	dbm "github.com/tendermint/tmlibs/db"
 	"github.com/tendermint/tmlibs/log"
+
+	cfg "github.com/tendermint/tendermint/config"
+	"github.com/tendermint/tendermint/types"
 )
 
-func TestStateCopyEquals(t *testing.T) {
+// setupTestCase does setup common to all test cases
+func setupTestCase(t *testing.T) (func(t *testing.T), dbm.DB, *State) {
 	config := cfg.ResetTestRoot("state_")
-
-	// Get State db
 	stateDB := dbm.NewDB("state", config.DBBackend, config.DBDir())
-	state := GetState(stateDB, config.GenesisFile())
+	state, err := GetState(stateDB, config.GenesisFile())
+	assert.NoError(t, err, "expected no error on GetState")
 	state.SetLogger(log.TestingLogger())
 
-	stateCopy := state.Copy()
+	tearDown := func(t *testing.T) {}
 
-	if !state.Equals(stateCopy) {
-		t.Fatal("expected state and its copy to be identical. got %v\n expected %v\n", stateCopy, state)
-	}
+	return tearDown, stateDB, state
+}
 
-	stateCopy.LastBlockHeight += 1
+func TestStateCopy(t *testing.T) {
+	tearDown, _, state := setupTestCase(t)
+	defer tearDown(t)
+	assert := assert.New(t)
 
-	if state.Equals(stateCopy) {
-		t.Fatal("expected states to be different. got same %v", state)
-	}
+	stateCopy := state.Copy()
+
+	assert.True(state.Equals(stateCopy),
+		cmn.Fmt("expected state and its copy to be identical. got %v\n expected %v\n", stateCopy, state))
+	stateCopy.LastBlockHeight++
+	assert.False(state.Equals(stateCopy), cmn.Fmt("expected states to be different. got same %v", state))
 }
 
 func TestStateSaveLoad(t *testing.T) {
-	config := cfg.ResetTestRoot("state_")
-	// Get State db
-	stateDB := dbm.NewDB("state", config.DBBackend, config.DBDir())
-	state := GetState(stateDB, config.GenesisFile())
-	state.SetLogger(log.TestingLogger())
+	tearDown, stateDB, state := setupTestCase(t)
+	defer tearDown(t)
+	assert := assert.New(t)
 
-	state.LastBlockHeight += 1
+	state.LastBlockHeight++
 	state.Save()
 
 	loadedState := LoadState(stateDB)
-	if !state.Equals(loadedState) {
-		t.Fatal("expected state and its copy to be identical. got %v\n expected %v\n", loadedState, state)
-	}
+	assert.True(state.Equals(loadedState),
+		cmn.Fmt("expected state and its copy to be identical. got %v\n expected %v\n", loadedState, state))
 }
 
 func TestABCIResponsesSaveLoad(t *testing.T) {
+	tearDown, _, state := setupTestCase(t)
+	defer tearDown(t)
 	assert := assert.New(t)
 
-	config := cfg.ResetTestRoot("state_")
-	stateDB := dbm.NewDB("state", config.DBBackend, config.DBDir())
-	state := GetState(stateDB, config.GenesisFile())
-	state.SetLogger(log.TestingLogger())
-
-	state.LastBlockHeight += 1
+	state.LastBlockHeight++
 
 	// build mock responses
 	block := makeBlock(2, state)
@@ -74,5 +80,124 @@ func TestABCIResponsesSaveLoad(t *testing.T) {
 
 	state.SaveABCIResponses(abciResponses)
 	abciResponses2 := state.LoadABCIResponses()
-	assert.Equal(abciResponses, abciResponses2, fmt.Sprintf("ABCIResponses don't match: Got %v, Expected %v", abciResponses2, abciResponses))
+	assert.Equal(abciResponses, abciResponses2,
+		cmn.Fmt("ABCIResponses don't match: Got %v, Expected %v", abciResponses2, abciResponses))
+}
+
+func TestValidatorSimpleSaveLoad(t *testing.T) {
+	tearDown, _, state := setupTestCase(t)
+	defer tearDown(t)
+	assert := assert.New(t)
+
+	// cant load anything for height 0
+	v, err := state.LoadValidators(0)
+	assert.IsType(ErrNoValSetForHeight{}, err, "expected err at height 0")
+
+	// should be able to load for height 1
+	v, err = state.LoadValidators(1)
+	assert.Nil(err, "expected no err at height 1")
+	assert.Equal(v.Hash(), state.Validators.Hash(), "expected validator hashes to match")
+
+	// increment height, save; should be able to load for next height
+	state.LastBlockHeight++
+	state.saveValidatorsInfo()
+	v, err = state.LoadValidators(state.LastBlockHeight + 1)
+	assert.Nil(err, "expected no err")
+	assert.Equal(v.Hash(), state.Validators.Hash(), "expected validator hashes to match")
+
+	// increment height, save; should be able to load for next height
+	state.LastBlockHeight += 10
+	state.saveValidatorsInfo()
+	v, err = state.LoadValidators(state.LastBlockHeight + 1)
+	assert.Nil(err, "expected no err")
+	assert.Equal(v.Hash(), state.Validators.Hash(), "expected validator hashes to match")
+
+	// should be able to load for next next height
+	_, err = state.LoadValidators(state.LastBlockHeight + 2)
+	assert.IsType(ErrNoValSetForHeight{}, err, "expected err at unknown height")
+}
+
+func TestValidatorChangesSaveLoad(t *testing.T) {
+	tearDown, _, state := setupTestCase(t)
+	defer tearDown(t)
+	assert := assert.New(t)
+
+	// change vals at these heights
+	changeHeights := []int{1, 2, 4, 5, 10, 15, 16, 17, 20}
+	N := len(changeHeights)
+
+	// each valset is just one validator.
+	// create list of them
+	pubkeys := make([]crypto.PubKey, N+1)
+	pubkeys[0] = state.GenesisDoc.Validators[0].PubKey
+	for i := 1; i < N+1; i++ {
+		pubkeys[i] = crypto.GenPrivKeyEd25519().PubKey()
+	}
+
+	// build the validator history by running SetBlockAndValidators
+	// with the right validator set for each height
+	highestHeight := changeHeights[N-1] + 5
+	changeIndex := 0
+	pubkey := pubkeys[changeIndex]
+	for i := 1; i < highestHeight; i++ {
+		// when we get to a change height,
+		// use the next pubkey
+		if changeIndex < len(changeHeights) && i == changeHeights[changeIndex] {
+			changeIndex++
+			pubkey = pubkeys[changeIndex]
+		}
+		header, parts, responses := makeHeaderPartsResponses(state, i, pubkey)
+		state.SetBlockAndValidators(header, parts, responses)
+		state.saveValidatorsInfo()
+	}
+
+	// make all the test cases by using the same validator until after the change
+	testCases := make([]valChangeTestCase, highestHeight)
+	changeIndex = 0
+	pubkey = pubkeys[changeIndex]
+	for i := 1; i < highestHeight+1; i++ {
+		// we we get to the height after a change height
+		// use the next pubkey (note our counter starts at 0 this time)
+		if changeIndex < len(changeHeights) && i == changeHeights[changeIndex]+1 {
+			changeIndex++
+			pubkey = pubkeys[changeIndex]
+		}
+		testCases[i-1] = valChangeTestCase{i, pubkey}
+	}
+
+	for _, testCase := range testCases {
+		v, err := state.LoadValidators(testCase.height)
+		assert.Nil(err, fmt.Sprintf("expected no err at height %d", testCase.height))
+		assert.Equal(v.Size(), 1, "validator set size is greater than 1: %d", v.Size())
+		addr, _ := v.GetByIndex(0)
+
+		assert.Equal(addr, testCase.vals.Address(), fmt.Sprintf("unexpected pubkey at height %d", testCase.height))
+	}
+}
+
+func makeHeaderPartsResponses(state *State, height int,
+	pubkey crypto.PubKey) (*types.Header, types.PartSetHeader, *ABCIResponses) {
+
+	block := makeBlock(height, state)
+	_, val := state.Validators.GetByIndex(0)
+	abciResponses := &ABCIResponses{
+		Height: height,
+	}
+
+	// if the pubkey is new, remove the old and add the new
+	if !bytes.Equal(pubkey.Bytes(), val.PubKey.Bytes()) {
+		abciResponses.EndBlock = abci.ResponseEndBlock{
+			Diffs: []*abci.Validator{
+				{val.PubKey.Bytes(), 0},
+				{pubkey.Bytes(), 10},
+			},
+		}
+	}
+
+	return block.Header, types.PartSetHeader{}, abciResponses
+}
+
+type valChangeTestCase struct {
+	height int
+	vals   crypto.PubKey
 }
diff --git a/test/app/counter_test.sh b/test/app/counter_test.sh
index cc5c38b25..0198f85cd 100644
--- a/test/app/counter_test.sh
+++ b/test/app/counter_test.sh
@@ -23,39 +23,42 @@ function getCode() {
 	else
 		# this wont actually work if theres an error ...
 		echo "$R" | jq .code
-	fi 
+	fi
 }
 
 function sendTx() {
 	TX=$1
 	if [[ "$GRPC_BROADCAST_TX" == "" ]]; then
-		RESPONSE=`curl -s localhost:46657/broadcast_tx_commit?tx=0x$TX`
-		ERROR=`echo $RESPONSE | jq .error`
+		RESPONSE=$(curl -s localhost:46657/broadcast_tx_commit?tx=0x"$TX")
+		IS_ERR=$(echo "$RESPONSE" | jq 'has("error")')
+		ERROR=$(echo "$RESPONSE" | jq '.error')
 		ERROR=$(echo "$ERROR" | tr -d '"') # remove surrounding quotes
 
-		RESPONSE=`echo $RESPONSE | jq .result`
+		RESPONSE=$(echo "$RESPONSE" | jq '.result')
 	else
 	 	if [  -f grpc_client ]; then
 			rm grpc_client
 	     	fi
 		echo "... building grpc_client"
-		go build -o grpc_client grpc_client.go 
-		RESPONSE=`./grpc_client $TX`
+		go build -o grpc_client grpc_client.go
+		RESPONSE=$(./grpc_client "$TX")
+		IS_ERR=false
 		ERROR=""
 	fi
 
 	echo "RESPONSE"
-	echo $RESPONSE
+	echo "$RESPONSE"
 
-	echo $RESPONSE | jq . &> /dev/null
+	echo "$RESPONSE" | jq . &> /dev/null
 	IS_JSON=$?
 	if [[ "$IS_JSON" != "0" ]]; then
+		IS_ERR=true
 		ERROR="$RESPONSE"
 	fi
-	APPEND_TX_RESPONSE=`echo $RESPONSE | jq .deliver_tx`
-	APPEND_TX_CODE=`getCode "$APPEND_TX_RESPONSE"`
-	CHECK_TX_RESPONSE=`echo $RESPONSE | jq .check_tx`
-	CHECK_TX_CODE=`getCode "$CHECK_TX_RESPONSE"`
+	APPEND_TX_RESPONSE=$(echo "$RESPONSE" | jq '.deliver_tx')
+	APPEND_TX_CODE=$(getCode "$APPEND_TX_RESPONSE")
+	CHECK_TX_RESPONSE=$(echo "$RESPONSE" | jq '.check_tx')
+	CHECK_TX_CODE=$(getCode "$CHECK_TX_RESPONSE")
 
 	echo "-------"
 	echo "TX $TX"
@@ -63,7 +66,7 @@ function sendTx() {
 	echo "ERROR $ERROR"
 	echo "----"
 
-	if [[ "$ERROR" != "" ]]; then
+	if $IS_ERR; then
 		echo "Unexpected error sending tx ($TX): $ERROR"
 		exit 1
 	fi
diff --git a/test/p2p/data/data/init.sh b/test/p2p/data/data/init.sh
deleted file mode 100755
index 41122a547..000000000
--- a/test/p2p/data/data/init.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#! /bin/bash
-# This is a sample bash script for MerkleEyes.
-# NOTE: mintnet expects data.sock to be created
-
-go get github.com/tendermint/merkleeyes/cmd/merkleeyes
-
-merkleeyes server --address="unix:///data/tendermint/data/data.sock"
\ No newline at end of file
diff --git a/test/p2p/data/mach1/core/genesis.json b/test/p2p/data/mach1/core/genesis.json
index 522f9831a..8d5c6c7b9 100644
--- a/test/p2p/data/mach1/core/genesis.json
+++ b/test/p2p/data/mach1/core/genesis.json
@@ -4,7 +4,7 @@
 	"genesis_time": "2016-06-24T20:01:19.322Z",
 	"validators": [
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach1",
 			"pub_key": {
         "type": "ed25519",
@@ -12,7 +12,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach2",
 			"pub_key": {
         "type": "ed25519",
@@ -20,7 +20,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach3",
 			"pub_key": {
         "type": "ed25519",
@@ -28,7 +28,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach4",
 			"pub_key": {
         "type": "ed25519",
diff --git a/test/p2p/data/mach2/core/genesis.json b/test/p2p/data/mach2/core/genesis.json
index 522f9831a..8d5c6c7b9 100644
--- a/test/p2p/data/mach2/core/genesis.json
+++ b/test/p2p/data/mach2/core/genesis.json
@@ -4,7 +4,7 @@
 	"genesis_time": "2016-06-24T20:01:19.322Z",
 	"validators": [
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach1",
 			"pub_key": {
         "type": "ed25519",
@@ -12,7 +12,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach2",
 			"pub_key": {
         "type": "ed25519",
@@ -20,7 +20,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach3",
 			"pub_key": {
         "type": "ed25519",
@@ -28,7 +28,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach4",
 			"pub_key": {
         "type": "ed25519",
diff --git a/test/p2p/data/mach3/core/genesis.json b/test/p2p/data/mach3/core/genesis.json
index 522f9831a..8d5c6c7b9 100644
--- a/test/p2p/data/mach3/core/genesis.json
+++ b/test/p2p/data/mach3/core/genesis.json
@@ -4,7 +4,7 @@
 	"genesis_time": "2016-06-24T20:01:19.322Z",
 	"validators": [
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach1",
 			"pub_key": {
         "type": "ed25519",
@@ -12,7 +12,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach2",
 			"pub_key": {
         "type": "ed25519",
@@ -20,7 +20,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach3",
 			"pub_key": {
         "type": "ed25519",
@@ -28,7 +28,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach4",
 			"pub_key": {
         "type": "ed25519",
diff --git a/test/p2p/data/mach4/core/genesis.json b/test/p2p/data/mach4/core/genesis.json
index 522f9831a..8d5c6c7b9 100644
--- a/test/p2p/data/mach4/core/genesis.json
+++ b/test/p2p/data/mach4/core/genesis.json
@@ -4,7 +4,7 @@
 	"genesis_time": "2016-06-24T20:01:19.322Z",
 	"validators": [
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach1",
 			"pub_key": {
         "type": "ed25519",
@@ -12,7 +12,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach2",
 			"pub_key": {
         "type": "ed25519",
@@ -20,7 +20,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach3",
 			"pub_key": {
         "type": "ed25519",
@@ -28,7 +28,7 @@
       }
 		},
 		{
-			"amount": 1,
+			"power": 1,
 			"name": "mach4",
 			"pub_key": {
         "type": "ed25519",
diff --git a/types/block.go b/types/block.go
index fee62e98c..c8cdf81a9 100644
--- a/types/block.go
+++ b/types/block.go
@@ -14,11 +14,6 @@ import (
 	"github.com/tendermint/tmlibs/merkle"
 )
 
-const (
-	MaxBlockSize         = 22020096 // 21MB TODO make it configurable
-	DefaultBlockPartSize = 65536    // 64kB TODO: put part size in parts header?
-)
-
 // Block defines the atomic unit of a Tendermint blockchain
 type Block struct {
 	*Header    `json:"header"`
diff --git a/types/block_meta.go b/types/block_meta.go
index 8e5bd43e5..6dd502e4f 100644
--- a/types/block_meta.go
+++ b/types/block_meta.go
@@ -1,10 +1,12 @@
 package types
 
+// BlockMeta contains meta information about a block - namely, it's ID and Header.
 type BlockMeta struct {
 	BlockID BlockID `json:"block_id"` // the block hash and partsethash
 	Header  *Header `json:"header"`   // The block's Header
 }
 
+// NewBlockMeta returns a new BlockMeta from the block and its blockParts.
 func NewBlockMeta(block *Block, blockParts *PartSet) *BlockMeta {
 	return &BlockMeta{
 		BlockID: BlockID{block.Hash(), blockParts.Header()},
diff --git a/types/genesis.go b/types/genesis.go
index 23b14c9e9..f1b2736f8 100644
--- a/types/genesis.go
+++ b/types/genesis.go
@@ -12,27 +12,23 @@ import (
 	cmn "github.com/tendermint/tmlibs/common"
 )
 
-//------------------------------------------------------------
-// we store the gendoc in the db
-
-var GenDocKey = []byte("GenDocKey")
-
 //------------------------------------------------------------
 // core types for a genesis definition
 
 // GenesisValidator is an initial validator.
 type GenesisValidator struct {
 	PubKey crypto.PubKey `json:"pub_key"`
-	Amount int64         `json:"amount"`
+	Power  int64         `json:"power"`
 	Name   string        `json:"name"`
 }
 
 // GenesisDoc defines the initial conditions for a tendermint blockchain, in particular its validator set.
 type GenesisDoc struct {
-	GenesisTime time.Time          `json:"genesis_time"`
-	ChainID     string             `json:"chain_id"`
-	Validators  []GenesisValidator `json:"validators"`
-	AppHash     data.Bytes         `json:"app_hash"`
+	GenesisTime     time.Time          `json:"genesis_time"`
+	ChainID         string             `json:"chain_id"`
+	ConsensusParams *ConsensusParams   `json:"consensus_params,omitempty"`
+	Validators      []GenesisValidator `json:"validators"`
+	AppHash         data.Bytes         `json:"app_hash"`
 }
 
 // SaveAs is a utility method for saving GenensisDoc as a JSON file.
@@ -48,12 +44,45 @@ func (genDoc *GenesisDoc) SaveAs(file string) error {
 func (genDoc *GenesisDoc) ValidatorHash() []byte {
 	vals := make([]*Validator, len(genDoc.Validators))
 	for i, v := range genDoc.Validators {
-		vals[i] = NewValidator(v.PubKey, v.Amount)
+		vals[i] = NewValidator(v.PubKey, v.Power)
 	}
 	vset := NewValidatorSet(vals)
 	return vset.Hash()
 }
 
+// ValidateAndComplete checks that all necessary fields are present
+// and fills in defaults for optional fields left empty
+func (genDoc *GenesisDoc) ValidateAndComplete() error {
+
+	if genDoc.ChainID == "" {
+		return errors.Errorf("Genesis doc must include non-empty chain_id")
+	}
+
+	if genDoc.ConsensusParams == nil {
+		genDoc.ConsensusParams = DefaultConsensusParams()
+	} else {
+		if err := genDoc.ConsensusParams.Validate(); err != nil {
+			return err
+		}
+	}
+
+	if len(genDoc.Validators) == 0 {
+		return errors.Errorf("The genesis file must have at least one validator")
+	}
+
+	for _, v := range genDoc.Validators {
+		if v.Power == 0 {
+			return errors.Errorf("The genesis file cannot contain validators with no voting power: %v", v)
+		}
+	}
+
+	if genDoc.GenesisTime.IsZero() {
+		genDoc.GenesisTime = time.Now()
+	}
+
+	return nil
+}
+
 //------------------------------------------------------------
 // Make genesis state from file
 
@@ -61,6 +90,14 @@ func (genDoc *GenesisDoc) ValidatorHash() []byte {
 func GenesisDocFromJSON(jsonBlob []byte) (*GenesisDoc, error) {
 	genDoc := GenesisDoc{}
 	err := json.Unmarshal(jsonBlob, &genDoc)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := genDoc.ValidateAndComplete(); err != nil {
+		return nil, err
+	}
+
 	return &genDoc, err
 }
 
@@ -72,10 +109,7 @@ func GenesisDocFromFile(genDocFile string) (*GenesisDoc, error) {
 	}
 	genDoc, err := GenesisDocFromJSON(jsonBlob)
 	if err != nil {
-		return nil, errors.Wrap(err, "Error reading GenesisDoc")
-	}
-	if genDoc.ChainID == "" {
-		return nil, errors.Errorf("Genesis doc %v must include non-empty chain_id", genDocFile)
+		return nil, errors.Wrap(err, cmn.Fmt("Error reading GenesisDoc at %v", genDocFile))
 	}
 	return genDoc, nil
 }
diff --git a/types/genesis_test.go b/types/genesis_test.go
new file mode 100644
index 000000000..fe997b690
--- /dev/null
+++ b/types/genesis_test.go
@@ -0,0 +1,89 @@
+package types
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	crypto "github.com/tendermint/go-crypto"
+)
+
+func TestGenesis(t *testing.T) {
+
+	// test some bad ones from raw json
+	testCases := [][]byte{
+		[]byte{},                                             // empty
+		[]byte{1, 1, 1, 1, 1},                                // junk
+		[]byte(`{}`),                                         // empty
+		[]byte(`{"chain_id": "mychain"}`),                    // missing validators
+		[]byte(`{"chain_id": "mychain", "validators": []`),   // missing validators
+		[]byte(`{"chain_id": "mychain", "validators": [{}]`), // missing validators
+		[]byte(`{"validators":[{"pub_key":
+		{"type":"ed25519","data":"961EAB8752E51A03618502F55C2B6E09C38C65635C64CCF3173ED452CF86C957"},
+		"power":10,"name":""}]}`), // missing chain_id
+	}
+
+	for _, testCase := range testCases {
+		_, err := GenesisDocFromJSON(testCase)
+		assert.Error(t, err, "expected error for empty genDoc json")
+	}
+
+	// test a good one by raw json
+	genDocBytes := []byte(`{"genesis_time":"0001-01-01T00:00:00Z","chain_id":"test-chain-QDKdJr","consensus_params":null,"validators":[{"pub_key":{"type":"ed25519","data":"961EAB8752E51A03618502F55C2B6E09C38C65635C64CCF3173ED452CF86C957"},"power":10,"name":""}],"app_hash":""}`)
+	_, err := GenesisDocFromJSON(genDocBytes)
+	assert.NoError(t, err, "expected no error for good genDoc json")
+
+	// create a base gendoc from struct
+	baseGenDoc := &GenesisDoc{
+		ChainID:    "abc",
+		Validators: []GenesisValidator{{crypto.GenPrivKeyEd25519().PubKey(), 10, "myval"}},
+	}
+	genDocBytes, err = json.Marshal(baseGenDoc)
+	assert.NoError(t, err, "error marshalling genDoc")
+
+	// test base gendoc and check consensus params were filled
+	genDoc, err := GenesisDocFromJSON(genDocBytes)
+	assert.NoError(t, err, "expected no error for valid genDoc json")
+	assert.NotNil(t, genDoc.ConsensusParams, "expected consensus params to be filled in")
+
+	// create json with consensus params filled
+	genDocBytes, err = json.Marshal(genDoc)
+	assert.NoError(t, err, "error marshalling genDoc")
+	genDoc, err = GenesisDocFromJSON(genDocBytes)
+	assert.NoError(t, err, "expected no error for valid genDoc json")
+
+	// test with invalid consensus params
+	genDoc.ConsensusParams.BlockSizeParams.MaxBytes = 0
+	genDocBytes, err = json.Marshal(genDoc)
+	assert.NoError(t, err, "error marshalling genDoc")
+	genDoc, err = GenesisDocFromJSON(genDocBytes)
+	assert.Error(t, err, "expected error for genDoc json with block size of 0")
+}
+
+func newConsensusParams(blockSize, partSize int) ConsensusParams {
+	return ConsensusParams{
+		BlockSizeParams:   BlockSizeParams{MaxBytes: blockSize},
+		BlockGossipParams: BlockGossipParams{BlockPartSizeBytes: partSize},
+	}
+
+}
+
+func TestConsensusParams(t *testing.T) {
+
+	testCases := []struct {
+		params ConsensusParams
+		valid  bool
+	}{
+		{newConsensusParams(1, 1), true},
+		{newConsensusParams(1, 0), false},
+		{newConsensusParams(0, 1), false},
+		{newConsensusParams(0, 0), false},
+	}
+	for _, testCase := range testCases {
+		if testCase.valid {
+			assert.NoError(t, testCase.params.Validate(), "expected no error for valid params")
+		} else {
+			assert.Error(t, testCase.params.Validate(), "expected error for non valid params")
+		}
+	}
+}
diff --git a/types/heartbeat.go b/types/heartbeat.go
index 378f6202b..40a7b01b0 100644
--- a/types/heartbeat.go
+++ b/types/heartbeat.go
@@ -10,6 +10,8 @@ import (
 	cmn "github.com/tendermint/tmlibs/common"
 )
 
+// Heartbeat is a simple vote-like structure so validators can alert others that
+// they are alive and waiting for transactions.
 type Heartbeat struct {
 	ValidatorAddress data.Bytes       `json:"validator_address"`
 	ValidatorIndex   int              `json:"validator_index"`
@@ -19,6 +21,7 @@ type Heartbeat struct {
 	Signature        crypto.Signature `json:"signature"`
 }
 
+// WriteSignBytes writes the Heartbeat for signing.
 func (heartbeat *Heartbeat) WriteSignBytes(chainID string, w io.Writer, n *int, err *error) {
 	wire.WriteJSON(CanonicalJSONOnceHeartbeat{
 		chainID,
@@ -26,11 +29,13 @@ func (heartbeat *Heartbeat) WriteSignBytes(chainID string, w io.Writer, n *int,
 	}, w, n, err)
 }
 
+// Copy makes a copy of the Heartbeat.
 func (heartbeat *Heartbeat) Copy() *Heartbeat {
 	heartbeatCopy := *heartbeat
 	return &heartbeatCopy
 }
 
+// String returns a string representation of the Heartbeat.
 func (heartbeat *Heartbeat) String() string {
 	if heartbeat == nil {
 		return "nil-heartbeat"
diff --git a/types/keys.go b/types/keys.go
index 90591b959..992551191 100644
--- a/types/keys.go
+++ b/types/keys.go
@@ -1,5 +1,6 @@
 package types
 
+// UNSTABLE
 var (
 	PeerStateKey     = "ConsensusReactor.peerState"
 	PeerMempoolChKey = "MempoolReactor.peerMempoolCh"
diff --git a/types/params.go b/types/params.go
new file mode 100644
index 000000000..495d1fd48
--- /dev/null
+++ b/types/params.go
@@ -0,0 +1,87 @@
+package types
+
+import (
+	"github.com/pkg/errors"
+)
+
+const (
+	maxBlockSizeBytes = 104857600 // 100MB
+)
+
+// ConsensusParams contains consensus critical parameters
+// that determine the validity of blocks.
+type ConsensusParams struct {
+	BlockSizeParams   `json:"block_size_params"`
+	TxSizeParams      `json:"tx_size_params"`
+	BlockGossipParams `json:"block_gossip_params"`
+}
+
+// BlockSizeParams contain limits on the block size.
+type BlockSizeParams struct {
+	MaxBytes int `json:"max_bytes"` // NOTE: must not be 0
+	MaxTxs   int `json:"max_txs"`
+	MaxGas   int `json:"max_gas"`
+}
+
+// TxSizeParams contain limits on the tx size.
+type TxSizeParams struct {
+	MaxBytes int `json:"max_bytes"`
+	MaxGas   int `json:"max_gas"`
+}
+
+// BlockGossipParams determine consensus critical elements of how blocks are gossiped
+type BlockGossipParams struct {
+	BlockPartSizeBytes int `json:"block_part_size_bytes"` // NOTE: must not be 0
+}
+
+// DefaultConsensusParams returns a default ConsensusParams.
+func DefaultConsensusParams() *ConsensusParams {
+	return &ConsensusParams{
+		DefaultBlockSizeParams(),
+		DefaultTxSizeParams(),
+		DefaultBlockGossipParams(),
+	}
+}
+
+// DefaultBlockSizeParams returns a default BlockSizeParams.
+func DefaultBlockSizeParams() BlockSizeParams {
+	return BlockSizeParams{
+		MaxBytes: 22020096, // 21MB
+		MaxTxs:   100000,
+		MaxGas:   -1,
+	}
+}
+
+// DefaultTxSizeParams returns a default TxSizeParams.
+func DefaultTxSizeParams() TxSizeParams {
+	return TxSizeParams{
+		MaxBytes: 10240, // 10kB
+		MaxGas:   -1,
+	}
+}
+
+// DefaultBlockGossipParams returns a default BlockGossipParams.
+func DefaultBlockGossipParams() BlockGossipParams {
+	return BlockGossipParams{
+		BlockPartSizeBytes: 65536, // 64kB,
+	}
+}
+
+// Validate validates the ConsensusParams to ensure all values
+// are within their allowed limits, and returns an error if they are not.
+func (params *ConsensusParams) Validate() error {
+	// ensure some values are greater than 0
+	if params.BlockSizeParams.MaxBytes <= 0 {
+		return errors.Errorf("BlockSizeParams.MaxBytes must be greater than 0. Got %d", params.BlockSizeParams.MaxBytes)
+	}
+	if params.BlockGossipParams.BlockPartSizeBytes <= 0 {
+		return errors.Errorf("BlockGossipParams.BlockPartSizeBytes must be greater than 0. Got %d", params.BlockGossipParams.BlockPartSizeBytes)
+	}
+
+	// ensure blocks aren't too big
+	if params.BlockSizeParams.MaxBytes > maxBlockSizeBytes {
+		return errors.Errorf("BlockSizeParams.MaxBytes is too big. %d > %d",
+			params.BlockSizeParams.MaxBytes, maxBlockSizeBytes)
+	}
+	return nil
+}
diff --git a/types/priv_validator.go b/types/priv_validator.go
index 690824934..8834eb7cc 100644
--- a/types/priv_validator.go
+++ b/types/priv_validator.go
@@ -11,10 +11,10 @@ import (
 
 	crypto "github.com/tendermint/go-crypto"
 	data "github.com/tendermint/go-wire/data"
-	. "github.com/tendermint/tmlibs/common"
-	"github.com/tendermint/tmlibs/log"
+	cmn "github.com/tendermint/tmlibs/common"
 )
 
+// TODO: type ?
 const (
 	stepNone      = 0 // Used to distinguish the initial state
 	stepPropose   = 1
@@ -29,12 +29,26 @@ func voteToStep(vote *Vote) int8 {
 	case VoteTypePrecommit:
 		return stepPrecommit
 	default:
-		PanicSanity("Unknown vote type")
+		cmn.PanicSanity("Unknown vote type")
 		return 0
 	}
 }
 
-type PrivValidator struct {
+// PrivValidator defines the functionality of a local Tendermint validator
+// that signs votes, proposals, and heartbeats, and never double signs.
+type PrivValidator interface {
+	GetAddress() data.Bytes // redundant since .PubKey().Address()
+	GetPubKey() crypto.PubKey
+
+	SignVote(chainID string, vote *Vote) error
+	SignProposal(chainID string, proposal *Proposal) error
+	SignHeartbeat(chainID string, heartbeat *Heartbeat) error
+}
+
+// PrivValidatorFS implements PrivValidator using data persisted to disk
+// to prevent double signing. The Signer itself can be mutated to use
+// something besides the default, for instance a hardware signer.
+type PrivValidatorFS struct {
 	Address       data.Bytes       `json:"address"`
 	PubKey        crypto.PubKey    `json:"pub_key"`
 	LastHeight    int              `json:"last_height"`
@@ -53,121 +67,124 @@ type PrivValidator struct {
 	mtx      sync.Mutex
 }
 
-// This is used to sign votes.
+// Signer is an interface that defines how to sign messages.
 // It is the caller's duty to verify the msg before calling Sign,
 // eg. to avoid double signing.
-// Currently, the only callers are SignVote and SignProposal
+// Currently, the only callers are SignVote, SignProposal, and SignHeartbeat.
 type Signer interface {
-	PubKey() crypto.PubKey
-	Sign(msg []byte) crypto.Signature
+	Sign(msg []byte) (crypto.Signature, error)
 }
 
-// Implements Signer
+// DefaultSigner implements Signer.
+// It uses a standard, unencrypted crypto.PrivKey.
 type DefaultSigner struct {
-	priv crypto.PrivKey
+	PrivKey crypto.PrivKey `json:"priv_key"`
 }
 
+// NewDefaultSigner returns an instance of DefaultSigner.
 func NewDefaultSigner(priv crypto.PrivKey) *DefaultSigner {
-	return &DefaultSigner{priv: priv}
-}
-
-// Implements Signer
-func (ds *DefaultSigner) Sign(msg []byte) crypto.Signature {
-	return ds.priv.Sign(msg)
+	return &DefaultSigner{
+		PrivKey: priv,
+	}
 }
 
-// Implements Signer
-func (ds *DefaultSigner) PubKey() crypto.PubKey {
-	return ds.priv.PubKey()
+// Sign implements Signer. It signs the byte slice with a private key.
+func (ds *DefaultSigner) Sign(msg []byte) (crypto.Signature, error) {
+	return ds.PrivKey.Sign(msg), nil
 }
 
-func (privVal *PrivValidator) SetSigner(s Signer) {
-	privVal.Signer = s
-	privVal.setPubKeyAndAddress()
+// GetAddress returns the address of the validator.
+// Implements PrivValidator.
+func (pv *PrivValidatorFS) GetAddress() data.Bytes {
+	return pv.Address
 }
 
-// Overwrite address and pubkey for convenience
-func (privVal *PrivValidator) setPubKeyAndAddress() {
-	privVal.PubKey = privVal.Signer.PubKey()
-	privVal.Address = privVal.PubKey.Address()
+// GetPubKey returns the public key of the validator.
+// Implements PrivValidator.
+func (pv *PrivValidatorFS) GetPubKey() crypto.PubKey {
+	return pv.PubKey
 }
 
-// Generates a new validator with private key.
-func GenPrivValidator() *PrivValidator {
+// GenPrivValidatorFS generates a new validator with randomly generated private key
+// and sets the filePath, but does not call Save().
+func GenPrivValidatorFS(filePath string) *PrivValidatorFS {
 	privKey := crypto.GenPrivKeyEd25519().Wrap()
-	pubKey := privKey.PubKey()
-	return &PrivValidator{
-		Address:  pubKey.Address(),
-		PubKey:   pubKey,
+	return &PrivValidatorFS{
+		Address:  privKey.PubKey().Address(),
+		PubKey:   privKey.PubKey(),
 		PrivKey:  privKey,
 		LastStep: stepNone,
-		filePath: "",
 		Signer:   NewDefaultSigner(privKey),
+		filePath: filePath,
 	}
 }
 
-func LoadPrivValidator(filePath string) *PrivValidator {
-	privValJSONBytes, err := ioutil.ReadFile(filePath)
-	if err != nil {
-		Exit(err.Error())
-	}
-	privVal := PrivValidator{}
-	err = json.Unmarshal(privValJSONBytes, &privVal)
-	if err != nil {
-		Exit(Fmt("Error reading PrivValidator from %v: %v\n", filePath, err))
-	}
-
-	privVal.filePath = filePath
-	privVal.Signer = NewDefaultSigner(privVal.PrivKey)
-	privVal.setPubKeyAndAddress()
-	return &privVal
+// LoadPrivValidatorFS loads a PrivValidatorFS from the filePath.
+func LoadPrivValidatorFS(filePath string) *PrivValidatorFS {
+	return LoadPrivValidatorFSWithSigner(filePath, func(privVal PrivValidator) Signer {
+		return NewDefaultSigner(privVal.(*PrivValidatorFS).PrivKey)
+	})
 }
 
-func LoadOrGenPrivValidator(filePath string, logger log.Logger) *PrivValidator {
-	var privValidator *PrivValidator
+// LoadOrGenPrivValidatorFS loads a PrivValidatorFS from the given filePath
+// or else generates a new one and saves it to the filePath.
+func LoadOrGenPrivValidatorFS(filePath string) *PrivValidatorFS {
+	var privVal *PrivValidatorFS
 	if _, err := os.Stat(filePath); err == nil {
-		privValidator = LoadPrivValidator(filePath)
-		logger.Info("Loaded PrivValidator",
-			"file", filePath, "privValidator", privValidator)
+		privVal = LoadPrivValidatorFS(filePath)
 	} else {
-		privValidator = GenPrivValidator()
-		privValidator.SetFile(filePath)
-		privValidator.Save()
-		logger.Info("Generated PrivValidator", "file", filePath)
+		privVal = GenPrivValidatorFS(filePath)
+		privVal.Save()
 	}
-	return privValidator
+	return privVal
 }
 
-func (privVal *PrivValidator) SetFile(filePath string) {
-	privVal.mtx.Lock()
-	defer privVal.mtx.Unlock()
+// LoadPrivValidatorWithSigner loads a PrivValidatorFS with a custom
+// signer object. The PrivValidatorFS handles double signing prevention by persisting
+// data to the filePath, while the Signer handles the signing.
+// If the filePath does not exist, the PrivValidatorFS must be created manually and saved.
+func LoadPrivValidatorFSWithSigner(filePath string, signerFunc func(PrivValidator) Signer) *PrivValidatorFS {
+	privValJSONBytes, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		cmn.Exit(err.Error())
+	}
+	privVal := &PrivValidatorFS{}
+	err = json.Unmarshal(privValJSONBytes, &privVal)
+	if err != nil {
+		cmn.Exit(cmn.Fmt("Error reading PrivValidator from %v: %v\n", filePath, err))
+	}
+
 	privVal.filePath = filePath
+	privVal.Signer = signerFunc(privVal)
+	return privVal
 }
 
-func (privVal *PrivValidator) Save() {
+// Save persists the PrivValidatorFS to disk.
+func (privVal *PrivValidatorFS) Save() {
 	privVal.mtx.Lock()
 	defer privVal.mtx.Unlock()
 	privVal.save()
 }
 
-func (privVal *PrivValidator) save() {
+func (privVal *PrivValidatorFS) save() {
 	if privVal.filePath == "" {
-		PanicSanity("Cannot save PrivValidator: filePath not set")
+		cmn.PanicSanity("Cannot save PrivValidator: filePath not set")
 	}
 	jsonBytes, err := json.Marshal(privVal)
 	if err != nil {
 		// `@; BOOM!!!
-		PanicCrisis(err)
+		cmn.PanicCrisis(err)
 	}
-	err = WriteFileAtomic(privVal.filePath, jsonBytes, 0600)
+	err = cmn.WriteFileAtomic(privVal.filePath, jsonBytes, 0600)
 	if err != nil {
 		// `@; BOOM!!!
-		PanicCrisis(err)
+		cmn.PanicCrisis(err)
 	}
 }
 
+// Reset resets all fields in the PrivValidatorFS.
 // NOTE: Unsafe!
-func (privVal *PrivValidator) Reset() {
+func (privVal *PrivValidatorFS) Reset() {
 	privVal.LastHeight = 0
 	privVal.LastRound = 0
 	privVal.LastStep = 0
@@ -176,22 +193,22 @@ func (privVal *PrivValidator) Reset() {
 	privVal.Save()
 }
 
-func (privVal *PrivValidator) GetAddress() []byte {
-	return privVal.Address
-}
-
-func (privVal *PrivValidator) SignVote(chainID string, vote *Vote) error {
+// SignVote signs a canonical representation of the vote, along with the chainID.
+// Implements PrivValidator.
+func (privVal *PrivValidatorFS) SignVote(chainID string, vote *Vote) error {
 	privVal.mtx.Lock()
 	defer privVal.mtx.Unlock()
 	signature, err := privVal.signBytesHRS(vote.Height, vote.Round, voteToStep(vote), SignBytes(chainID, vote))
 	if err != nil {
-		return errors.New(Fmt("Error signing vote: %v", err))
+		return errors.New(cmn.Fmt("Error signing vote: %v", err))
 	}
 	vote.Signature = signature
 	return nil
 }
 
-func (privVal *PrivValidator) SignProposal(chainID string, proposal *Proposal) error {
+// SignProposal signs a canonical representation of the proposal, along with the chainID.
+// Implements PrivValidator.
+func (privVal *PrivValidatorFS) SignProposal(chainID string, proposal *Proposal) error {
 	privVal.mtx.Lock()
 	defer privVal.mtx.Unlock()
 	signature, err := privVal.signBytesHRS(proposal.Height, proposal.Round, stepPropose, SignBytes(chainID, proposal))
@@ -202,8 +219,11 @@ func (privVal *PrivValidator) SignProposal(chainID string, proposal *Proposal) e
 	return nil
 }
 
-// check if there's a regression. Else sign and write the hrs+signature to disk
-func (privVal *PrivValidator) signBytesHRS(height, round int, step int8, signBytes []byte) (crypto.Signature, error) {
+// signBytesHRS signs the given signBytes if the height/round/step (HRS)
+// are greater than the latest state. If the HRS are equal,
+// it returns the privValidator.LastSignature.
+func (privVal *PrivValidatorFS) signBytesHRS(height, round int, step int8, signBytes []byte) (crypto.Signature, error) {
+
 	sig := crypto.Signature{}
 	// If height regression, err
 	if privVal.LastHeight > height {
@@ -222,7 +242,7 @@ func (privVal *PrivValidator) signBytesHRS(height, round int, step int8, signByt
 			} else if privVal.LastStep == step {
 				if privVal.LastSignBytes != nil {
 					if privVal.LastSignature.Empty() {
-						PanicSanity("privVal: LastSignature is nil but LastSignBytes is not!")
+						cmn.PanicSanity("privVal: LastSignature is nil but LastSignBytes is not!")
 					}
 					// so we dont sign a conflicting vote or proposal
 					// NOTE: proposals are non-deterministic (include time),
@@ -238,7 +258,10 @@ func (privVal *PrivValidator) signBytesHRS(height, round int, step int8, signByt
 	}
 
 	// Sign
-	sig = privVal.Sign(signBytes)
+	sig, err := privVal.Sign(signBytes)
+	if err != nil {
+		return sig, err
+	}
 
 	// Persist height/round/step
 	privVal.LastHeight = height
@@ -249,30 +272,33 @@ func (privVal *PrivValidator) signBytesHRS(height, round int, step int8, signByt
 	privVal.save()
 
 	return sig, nil
-
 }
 
-func (privVal *PrivValidator) SignHeartbeat(chainID string, heartbeat *Heartbeat) error {
+// SignHeartbeat signs a canonical representation of the heartbeat, along with the chainID.
+// Implements PrivValidator.
+func (privVal *PrivValidatorFS) SignHeartbeat(chainID string, heartbeat *Heartbeat) error {
 	privVal.mtx.Lock()
 	defer privVal.mtx.Unlock()
-	heartbeat.Signature = privVal.Sign(SignBytes(chainID, heartbeat))
-	return nil
+	var err error
+	heartbeat.Signature, err = privVal.Sign(SignBytes(chainID, heartbeat))
+	return err
 }
 
-func (privVal *PrivValidator) String() string {
-	return fmt.Sprintf("PrivValidator{%v LH:%v, LR:%v, LS:%v}", privVal.Address, privVal.LastHeight, privVal.LastRound, privVal.LastStep)
+// String returns a string representation of the PrivValidatorFS.
+func (privVal *PrivValidatorFS) String() string {
+	return fmt.Sprintf("PrivValidator{%v LH:%v, LR:%v, LS:%v}", privVal.GetAddress(), privVal.LastHeight, privVal.LastRound, privVal.LastStep)
 }
 
 //-------------------------------------
 
-type PrivValidatorsByAddress []*PrivValidator
+type PrivValidatorsByAddress []*PrivValidatorFS
 
 func (pvs PrivValidatorsByAddress) Len() int {
 	return len(pvs)
 }
 
 func (pvs PrivValidatorsByAddress) Less(i, j int) bool {
-	return bytes.Compare(pvs[i].Address, pvs[j].Address) == -1
+	return bytes.Compare(pvs[i].GetAddress(), pvs[j].GetAddress()) == -1
 }
 
 func (pvs PrivValidatorsByAddress) Swap(i, j int) {
diff --git a/types/priv_validator_test.go b/types/priv_validator_test.go
index 1eb0b57db..ac91de861 100644
--- a/types/priv_validator_test.go
+++ b/types/priv_validator_test.go
@@ -4,14 +4,44 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	crypto "github.com/tendermint/go-crypto"
+	"github.com/tendermint/go-wire/data"
+	cmn "github.com/tendermint/tmlibs/common"
 )
 
-func TestLoadValidator(t *testing.T) {
+func TestGenLoadValidator(t *testing.T) {
+	assert := assert.New(t)
+
+	_, tempFilePath := cmn.Tempfile("priv_validator_")
+	privVal := GenPrivValidatorFS(tempFilePath)
+
+	height := 100
+	privVal.LastHeight = height
+	privVal.Save()
+	addr := privVal.GetAddress()
+
+	privVal = LoadPrivValidatorFS(tempFilePath)
+	assert.Equal(addr, privVal.GetAddress(), "expected privval addr to be the same")
+	assert.Equal(height, privVal.LastHeight, "expected privval.LastHeight to have been saved")
+}
+
+func TestLoadOrGenValidator(t *testing.T) {
+	assert := assert.New(t)
+
+	_, tempFilePath := cmn.Tempfile("priv_validator_")
+	os.Remove(tempFilePath)
+	privVal := LoadOrGenPrivValidatorFS(tempFilePath)
+	addr := privVal.GetAddress()
+	privVal = LoadOrGenPrivValidatorFS(tempFilePath)
+	assert.Equal(addr, privVal.GetAddress(), "expected privval addr to be the same")
+}
+
+func TestUnmarshalValidator(t *testing.T) {
 	assert, require := assert.New(t), require.New(t)
 
 	// create some fixed values
@@ -34,23 +64,23 @@ func TestLoadValidator(t *testing.T) {
     "type": "ed25519",
     "data": "%s"
   },
-  "priv_key": {
-    "type": "ed25519",
-    "data": "%s"
-  },
   "last_height": 0,
   "last_round": 0,
   "last_step": 0,
-  "last_signature": null
+  "last_signature": null,
+  "priv_key": {
+    "type": "ed25519",
+    "data": "%s"
+  }
 }`, addrStr, pubStr, privStr)
 
-	val := PrivValidator{}
+	val := PrivValidatorFS{}
 	err = json.Unmarshal([]byte(serialized), &val)
 	require.Nil(err, "%+v", err)
 
 	// make sure the values match
-	assert.EqualValues(addrBytes, val.Address)
-	assert.EqualValues(pubKey, val.PubKey)
+	assert.EqualValues(addrBytes, val.GetAddress())
+	assert.EqualValues(pubKey, val.GetPubKey())
 	assert.EqualValues(privKey, val.PrivKey)
 
 	// export it and make sure it is the same
@@ -58,3 +88,89 @@ func TestLoadValidator(t *testing.T) {
 	require.Nil(err, "%+v", err)
 	assert.JSONEq(serialized, string(out))
 }
+
+func TestSignVote(t *testing.T) {
+	assert := assert.New(t)
+
+	_, tempFilePath := cmn.Tempfile("priv_validator_")
+	privVal := GenPrivValidatorFS(tempFilePath)
+
+	block1 := BlockID{[]byte{1, 2, 3}, PartSetHeader{}}
+	block2 := BlockID{[]byte{3, 2, 1}, PartSetHeader{}}
+	height, round := 10, 1
+	voteType := VoteTypePrevote
+
+	// sign a vote for first time
+	vote := newVote(privVal.Address, 0, height, round, voteType, block1)
+	err := privVal.SignVote("mychainid", vote)
+	assert.NoError(err, "expected no error signing vote")
+
+	// try to sign the same vote again; should be fine
+	err = privVal.SignVote("mychainid", vote)
+	assert.NoError(err, "expected no error on signing same vote")
+
+	// now try some bad votes
+	cases := []*Vote{
+		newVote(privVal.Address, 0, height, round-1, voteType, block1),   // round regression
+		newVote(privVal.Address, 0, height-1, round, voteType, block1),   // height regression
+		newVote(privVal.Address, 0, height-2, round+4, voteType, block1), // height regression and different round
+		newVote(privVal.Address, 0, height, round, voteType, block2),     // different block
+	}
+
+	for _, c := range cases {
+		err = privVal.SignVote("mychainid", c)
+		assert.Error(err, "expected error on signing conflicting vote")
+	}
+}
+
+func TestSignProposal(t *testing.T) {
+	assert := assert.New(t)
+
+	_, tempFilePath := cmn.Tempfile("priv_validator_")
+	privVal := GenPrivValidatorFS(tempFilePath)
+
+	block1 := PartSetHeader{5, []byte{1, 2, 3}}
+	block2 := PartSetHeader{10, []byte{3, 2, 1}}
+	height, round := 10, 1
+
+	// sign a proposal for first time
+	proposal := newProposal(height, round, block1)
+	err := privVal.SignProposal("mychainid", proposal)
+	assert.NoError(err, "expected no error signing proposal")
+
+	// try to sign the same proposal again; should be fine
+	err = privVal.SignProposal("mychainid", proposal)
+	assert.NoError(err, "expected no error on signing same proposal")
+
+	// now try some bad Proposals
+	cases := []*Proposal{
+		newProposal(height, round-1, block1),   // round regression
+		newProposal(height-1, round, block1),   // height regression
+		newProposal(height-2, round+4, block1), // height regression and different round
+		newProposal(height, round, block2),     // different block
+	}
+
+	for _, c := range cases {
+		err = privVal.SignProposal("mychainid", c)
+		assert.Error(err, "expected error on signing conflicting proposal")
+	}
+}
+
+func newVote(addr data.Bytes, idx, height, round int, typ byte, blockID BlockID) *Vote {
+	return &Vote{
+		ValidatorAddress: addr,
+		ValidatorIndex:   idx,
+		Height:           height,
+		Round:            round,
+		Type:             typ,
+		BlockID:          blockID,
+	}
+}
+
+func newProposal(height, round int, partsHeader PartSetHeader) *Proposal {
+	return &Proposal{
+		Height:           height,
+		Round:            round,
+		BlockPartsHeader: partsHeader,
+	}
+}
diff --git a/types/proposal.go b/types/proposal.go
index 8406403c1..8fe959807 100644
--- a/types/proposal.go
+++ b/types/proposal.go
@@ -15,6 +15,11 @@ var (
 	ErrInvalidBlockPartHash      = errors.New("Error invalid block part hash")
 )
 
+// Proposal defines a block proposal for the consensus.
+// It refers to the block only by its PartSetHeader.
+// It must be signed by the correct proposer for the given Height/Round
+// to be considered valid. It may depend on votes from a previous round,
+// a so-called Proof-of-Lock (POL) round, as noted in the POLRound and POLBlockID.
 type Proposal struct {
 	Height           int              `json:"height"`
 	Round            int              `json:"round"`
@@ -24,7 +29,8 @@ type Proposal struct {
 	Signature        crypto.Signature `json:"signature"`
 }
 
-// polRound: -1 if no polRound.
+// NewProposal returns a new Proposal.
+// If there is no POLRound, polRound should be -1.
 func NewProposal(height int, round int, blockPartsHeader PartSetHeader, polRound int, polBlockID BlockID) *Proposal {
 	return &Proposal{
 		Height:           height,
@@ -35,11 +41,13 @@ func NewProposal(height int, round int, blockPartsHeader PartSetHeader, polRound
 	}
 }
 
+// String returns a string representation of the Proposal.
 func (p *Proposal) String() string {
 	return fmt.Sprintf("Proposal{%v/%v %v (%v,%v) %v}", p.Height, p.Round,
 		p.BlockPartsHeader, p.POLRound, p.POLBlockID, p.Signature)
 }
 
+// WriteSignBytes writes the Proposal bytes for signing
 func (p *Proposal) WriteSignBytes(chainID string, w io.Writer, n *int, err *error) {
 	wire.WriteJSON(CanonicalJSONOnceProposal{
 		ChainID:  chainID,
diff --git a/types/proposal_test.go b/types/proposal_test.go
index 622236b60..d1c991849 100644
--- a/types/proposal_test.go
+++ b/types/proposal_test.go
@@ -28,17 +28,17 @@ func BenchmarkProposalWriteSignBytes(b *testing.B) {
 }
 
 func BenchmarkProposalSign(b *testing.B) {
-	privVal := GenPrivValidator()
+	privVal := GenPrivValidatorFS("")
 	for i := 0; i < b.N; i++ {
-		privVal.Sign(SignBytes("test_chain_id", testProposal))
+		privVal.Signer.Sign(SignBytes("test_chain_id", testProposal))
 	}
 }
 
 func BenchmarkProposalVerifySignature(b *testing.B) {
 	signBytes := SignBytes("test_chain_id", testProposal)
-	privVal := GenPrivValidator()
-	signature := privVal.Sign(signBytes)
-	pubKey := privVal.PubKey
+	privVal := GenPrivValidatorFS("")
+	signature, _ := privVal.Signer.Sign(signBytes)
+	pubKey := privVal.GetPubKey()
 
 	for i := 0; i < b.N; i++ {
 		pubKey.VerifyBytes(SignBytes("test_chain_id", testProposal), signature)
diff --git a/types/protobuf.go b/types/protobuf.go
index 59994fea7..c8c9f8434 100644
--- a/types/protobuf.go
+++ b/types/protobuf.go
@@ -4,7 +4,8 @@ import (
 	"github.com/tendermint/abci/types"
 )
 
-// Convert tendermint types to protobuf types
+// TM2PB is used for converting Tendermint types to protobuf types.
+// UNSTABLE
 var TM2PB = tm2pb{}
 
 type tm2pb struct{}
diff --git a/types/services.go b/types/services.go
index 1805a0090..e34d846b5 100644
--- a/types/services.go
+++ b/types/services.go
@@ -4,6 +4,8 @@ import (
 	abci "github.com/tendermint/abci/types"
 )
 
+// NOTE: all types in this file are considered UNSTABLE
+
 //------------------------------------------------------
 // blockchain services types
 // NOTE: Interfaces used by RPC must be thread safe!
@@ -12,8 +14,10 @@ import (
 //------------------------------------------------------
 // mempool
 
+// Mempool defines the mempool interface.
 // Updates to the mempool need to be synchronized with committing a block
 // so apps can reset their transient state on Commit
+// UNSTABLE
 type Mempool interface {
 	Lock()
 	Unlock()
@@ -28,6 +32,8 @@ type Mempool interface {
 	EnableTxsAvailable()
 }
 
+// MockMempool is an empty implementation of a Mempool, useful for testing.
+// UNSTABLE
 type MockMempool struct {
 }
 
@@ -44,6 +50,8 @@ func (m MockMempool) EnableTxsAvailable()                          {}
 //------------------------------------------------------
 // blockstore
 
+// BlockStoreRPC is the block store interface used by the RPC.
+// UNSTABLE
 type BlockStoreRPC interface {
 	Height() int
 
@@ -55,6 +63,8 @@ type BlockStoreRPC interface {
 	LoadSeenCommit(height int) *Commit
 }
 
+// BlockStore defines the BlockStore interface.
+// UNSTABLE
 type BlockStore interface {
 	BlockStoreRPC
 	SaveBlock(block *Block, blockParts *PartSet, seenCommit *Commit)
diff --git a/types/tx.go b/types/tx.go
index 0334452e1..fbea8ff55 100644
--- a/types/tx.go
+++ b/types/tx.go
@@ -10,22 +10,26 @@ import (
 	"github.com/tendermint/tmlibs/merkle"
 )
 
+// Tx represents a transaction, which may contain arbitrary bytes.
 type Tx []byte
 
-// NOTE: this is the hash of the go-wire encoded Tx.
-// Tx has no types at this level, so just length-prefixed.
-// Alternatively, it may make sense to add types here and let
-// []byte be type 0x1 so we can have versioned txs if need be in the future.
+// Hash returns the hash of the go-wire encoded Tx.
+// Tx has no types at this level, so go-wire encoding only adds length-prefix.
+// NOTE: It may make sense to add types here one day and let []byte be type 0x1
+// so we can have versioned txs if need be in the future.
 func (tx Tx) Hash() []byte {
 	return merkle.SimpleHashFromBinary(tx)
 }
 
+// String returns a string representation of the Tx.
 func (tx Tx) String() string {
 	return fmt.Sprintf("Tx{%X}", []byte(tx))
 }
 
+// Txs is a slice of Tx.
 type Txs []Tx
 
+// Hash returns the simple Merkle root hash of the Txs.
 func (txs Txs) Hash() []byte {
 	// Recursive impl.
 	// Copied from tmlibs/merkle to avoid allocations
@@ -51,7 +55,7 @@ func (txs Txs) Index(tx Tx) int {
 	return -1
 }
 
-// Index returns the index of this transaction hash in the list, or -1 if not found
+// IndexByHash returns the index of this transaction hash in the list, or -1 if not found
 func (txs Txs) IndexByHash(hash []byte) int {
 	for i := range txs {
 		if bytes.Equal(txs[i].Hash(), hash) {
diff --git a/types/validator.go b/types/validator.go
index 24f8974f3..7b167b273 100644
--- a/types/validator.go
+++ b/types/validator.go
@@ -106,14 +106,15 @@ func (vc validatorCodec) Compare(o1 interface{}, o2 interface{}) int {
 //--------------------------------------------------------------------------------
 // For testing...
 
-func RandValidator(randPower bool, minPower int64) (*Validator, *PrivValidator) {
-	privVal := GenPrivValidator()
+// RandValidator returns a randomized validator, useful for testing.
+// UNSTABLE
+func RandValidator(randPower bool, minPower int64) (*Validator, *PrivValidatorFS) {
 	_, tempFilePath := cmn.Tempfile("priv_validator_")
-	privVal.SetFile(tempFilePath)
+	privVal := GenPrivValidatorFS(tempFilePath)
 	votePower := minPower
 	if randPower {
 		votePower += int64(cmn.RandUint32())
 	}
-	val := NewValidator(privVal.PubKey, votePower)
+	val := NewValidator(privVal.GetPubKey(), votePower)
 	return val, privVal
 }
diff --git a/types/validator_set.go b/types/validator_set.go
index e334ed9f3..3ec389a48 100644
--- a/types/validator_set.go
+++ b/types/validator_set.go
@@ -368,10 +368,12 @@ func (ac accumComparable) Less(o interface{}) bool {
 //----------------------------------------
 // For testing
 
+// RandValidatorSet returns a randomized validator set, useful for testing.
 // NOTE: PrivValidator are in order.
-func RandValidatorSet(numValidators int, votingPower int64) (*ValidatorSet, []*PrivValidator) {
+// UNSTABLE
+func RandValidatorSet(numValidators int, votingPower int64) (*ValidatorSet, []*PrivValidatorFS) {
 	vals := make([]*Validator, numValidators)
-	privValidators := make([]*PrivValidator, numValidators)
+	privValidators := make([]*PrivValidatorFS, numValidators)
 	for i := 0; i < numValidators; i++ {
 		val, privValidator := RandValidator(false, votingPower)
 		vals[i] = val
diff --git a/types/vote_set_test.go b/types/vote_set_test.go
index 84e13ac17..80ee6135c 100644
--- a/types/vote_set_test.go
+++ b/types/vote_set_test.go
@@ -11,7 +11,7 @@ import (
 )
 
 // NOTE: privValidators are in order
-func randVoteSet(height int, round int, type_ byte, numValidators int, votingPower int64) (*VoteSet, *ValidatorSet, []*PrivValidator) {
+func randVoteSet(height int, round int, type_ byte, numValidators int, votingPower int64) (*VoteSet, *ValidatorSet, []*PrivValidatorFS) {
 	valSet, privValidators := RandValidatorSet(numValidators, votingPower)
 	return NewVoteSet("test_chain_id", height, round, type_, valSet), valSet, privValidators
 }
@@ -59,8 +59,12 @@ func withBlockPartsHeader(vote *Vote, blockPartsHeader PartSetHeader) *Vote {
 	return vote
 }
 
-func signAddVote(privVal *PrivValidator, vote *Vote, voteSet *VoteSet) (bool, error) {
-	vote.Signature = privVal.Sign(SignBytes(voteSet.ChainID(), vote))
+func signAddVote(privVal *PrivValidatorFS, vote *Vote, voteSet *VoteSet) (bool, error) {
+	var err error
+	vote.Signature, err = privVal.Signer.Sign(SignBytes(voteSet.ChainID(), vote))
+	if err != nil {
+		return false, err
+	}
 	added, err := voteSet.AddVote(vote)
 	return added, err
 }
@@ -72,7 +76,7 @@ func TestAddVote(t *testing.T) {
 
 	// t.Logf(">> %v", voteSet)
 
-	if voteSet.GetByAddress(val0.Address) != nil {
+	if voteSet.GetByAddress(val0.GetAddress()) != nil {
 		t.Errorf("Expected GetByAddress(val0.Address) to be nil")
 	}
 	if voteSet.BitArray().GetIndex(0) {
@@ -84,7 +88,7 @@ func TestAddVote(t *testing.T) {
 	}
 
 	vote := &Vote{
-		ValidatorAddress: val0.Address,
+		ValidatorAddress: val0.GetAddress(),
 		ValidatorIndex:   0, // since privValidators are in order
 		Height:           height,
 		Round:            round,
@@ -96,7 +100,7 @@ func TestAddVote(t *testing.T) {
 		t.Error(err)
 	}
 
-	if voteSet.GetByAddress(val0.Address) == nil {
+	if voteSet.GetByAddress(val0.GetAddress()) == nil {
 		t.Errorf("Expected GetByAddress(val0.Address) to be present")
 	}
 	if !voteSet.BitArray().GetIndex(0) {
@@ -122,7 +126,7 @@ func Test2_3Majority(t *testing.T) {
 	}
 	// 6 out of 10 voted for nil.
 	for i := 0; i < 6; i++ {
-		vote := withValidator(voteProto, privValidators[i].Address, i)
+		vote := withValidator(voteProto, privValidators[i].GetAddress(), i)
 		signAddVote(privValidators[i], vote, voteSet)
 	}
 	blockID, ok := voteSet.TwoThirdsMajority()
@@ -132,7 +136,7 @@ func Test2_3Majority(t *testing.T) {
 
 	// 7th validator voted for some blockhash
 	{
-		vote := withValidator(voteProto, privValidators[6].Address, 6)
+		vote := withValidator(voteProto, privValidators[6].GetAddress(), 6)
 		signAddVote(privValidators[6], withBlockHash(vote, RandBytes(32)), voteSet)
 		blockID, ok = voteSet.TwoThirdsMajority()
 		if ok || !blockID.IsZero() {
@@ -142,7 +146,7 @@ func Test2_3Majority(t *testing.T) {
 
 	// 8th validator voted for nil.
 	{
-		vote := withValidator(voteProto, privValidators[7].Address, 7)
+		vote := withValidator(voteProto, privValidators[7].GetAddress(), 7)
 		signAddVote(privValidators[7], vote, voteSet)
 		blockID, ok = voteSet.TwoThirdsMajority()
 		if !ok || !blockID.IsZero() {
@@ -170,7 +174,7 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 	// 66 out of 100 voted for nil.
 	for i := 0; i < 66; i++ {
-		vote := withValidator(voteProto, privValidators[i].Address, i)
+		vote := withValidator(voteProto, privValidators[i].GetAddress(), i)
 		signAddVote(privValidators[i], vote, voteSet)
 	}
 	blockID, ok := voteSet.TwoThirdsMajority()
@@ -180,7 +184,7 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 	// 67th validator voted for nil
 	{
-		vote := withValidator(voteProto, privValidators[66].Address, 66)
+		vote := withValidator(voteProto, privValidators[66].GetAddress(), 66)
 		signAddVote(privValidators[66], withBlockHash(vote, nil), voteSet)
 		blockID, ok = voteSet.TwoThirdsMajority()
 		if ok || !blockID.IsZero() {
@@ -190,7 +194,7 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 	// 68th validator voted for a different BlockParts PartSetHeader
 	{
-		vote := withValidator(voteProto, privValidators[67].Address, 67)
+		vote := withValidator(voteProto, privValidators[67].GetAddress(), 67)
 		blockPartsHeader := PartSetHeader{blockPartsTotal, crypto.CRandBytes(32)}
 		signAddVote(privValidators[67], withBlockPartsHeader(vote, blockPartsHeader), voteSet)
 		blockID, ok = voteSet.TwoThirdsMajority()
@@ -201,7 +205,7 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 	// 69th validator voted for different BlockParts Total
 	{
-		vote := withValidator(voteProto, privValidators[68].Address, 68)
+		vote := withValidator(voteProto, privValidators[68].GetAddress(), 68)
 		blockPartsHeader := PartSetHeader{blockPartsTotal + 1, blockPartsHeader.Hash}
 		signAddVote(privValidators[68], withBlockPartsHeader(vote, blockPartsHeader), voteSet)
 		blockID, ok = voteSet.TwoThirdsMajority()
@@ -212,7 +216,7 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 	// 70th validator voted for different BlockHash
 	{
-		vote := withValidator(voteProto, privValidators[69].Address, 69)
+		vote := withValidator(voteProto, privValidators[69].GetAddress(), 69)
 		signAddVote(privValidators[69], withBlockHash(vote, RandBytes(32)), voteSet)
 		blockID, ok = voteSet.TwoThirdsMajority()
 		if ok || !blockID.IsZero() {
@@ -222,7 +226,7 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 	// 71st validator voted for the right BlockHash & BlockPartsHeader
 	{
-		vote := withValidator(voteProto, privValidators[70].Address, 70)
+		vote := withValidator(voteProto, privValidators[70].GetAddress(), 70)
 		signAddVote(privValidators[70], vote, voteSet)
 		blockID, ok = voteSet.TwoThirdsMajority()
 		if !ok || !blockID.Equals(BlockID{blockHash, blockPartsHeader}) {
@@ -246,7 +250,7 @@ func TestBadVotes(t *testing.T) {
 
 	// val0 votes for nil.
 	{
-		vote := withValidator(voteProto, privValidators[0].Address, 0)
+		vote := withValidator(voteProto, privValidators[0].GetAddress(), 0)
 		added, err := signAddVote(privValidators[0], vote, voteSet)
 		if !added || err != nil {
 			t.Errorf("Expected VoteSet.Add to succeed")
@@ -255,7 +259,7 @@ func TestBadVotes(t *testing.T) {
 
 	// val0 votes again for some block.
 	{
-		vote := withValidator(voteProto, privValidators[0].Address, 0)
+		vote := withValidator(voteProto, privValidators[0].GetAddress(), 0)
 		added, err := signAddVote(privValidators[0], withBlockHash(vote, RandBytes(32)), voteSet)
 		if added || err == nil {
 			t.Errorf("Expected VoteSet.Add to fail, conflicting vote.")
@@ -264,7 +268,7 @@ func TestBadVotes(t *testing.T) {
 
 	// val1 votes on another height
 	{
-		vote := withValidator(voteProto, privValidators[1].Address, 1)
+		vote := withValidator(voteProto, privValidators[1].GetAddress(), 1)
 		added, err := signAddVote(privValidators[1], withHeight(vote, height+1), voteSet)
 		if added || err == nil {
 			t.Errorf("Expected VoteSet.Add to fail, wrong height")
@@ -273,7 +277,7 @@ func TestBadVotes(t *testing.T) {
 
 	// val2 votes on another round
 	{
-		vote := withValidator(voteProto, privValidators[2].Address, 2)
+		vote := withValidator(voteProto, privValidators[2].GetAddress(), 2)
 		added, err := signAddVote(privValidators[2], withRound(vote, round+1), voteSet)
 		if added || err == nil {
 			t.Errorf("Expected VoteSet.Add to fail, wrong round")
@@ -282,7 +286,7 @@ func TestBadVotes(t *testing.T) {
 
 	// val3 votes of another type.
 	{
-		vote := withValidator(voteProto, privValidators[3].Address, 3)
+		vote := withValidator(voteProto, privValidators[3].GetAddress(), 3)
 		added, err := signAddVote(privValidators[3], withType(vote, VoteTypePrecommit), voteSet)
 		if added || err == nil {
 			t.Errorf("Expected VoteSet.Add to fail, wrong type")
@@ -307,7 +311,7 @@ func TestConflicts(t *testing.T) {
 
 	// val0 votes for nil.
 	{
-		vote := withValidator(voteProto, privValidators[0].Address, 0)
+		vote := withValidator(voteProto, privValidators[0].GetAddress(), 0)
 		added, err := signAddVote(privValidators[0], vote, voteSet)
 		if !added || err != nil {
 			t.Errorf("Expected VoteSet.Add to succeed")
@@ -316,7 +320,7 @@ func TestConflicts(t *testing.T) {
 
 	// val0 votes again for blockHash1.
 	{
-		vote := withValidator(voteProto, privValidators[0].Address, 0)
+		vote := withValidator(voteProto, privValidators[0].GetAddress(), 0)
 		added, err := signAddVote(privValidators[0], withBlockHash(vote, blockHash1), voteSet)
 		if added {
 			t.Errorf("Expected VoteSet.Add to fail, conflicting vote.")
@@ -331,7 +335,7 @@ func TestConflicts(t *testing.T) {
 
 	// val0 votes again for blockHash1.
 	{
-		vote := withValidator(voteProto, privValidators[0].Address, 0)
+		vote := withValidator(voteProto, privValidators[0].GetAddress(), 0)
 		added, err := signAddVote(privValidators[0], withBlockHash(vote, blockHash1), voteSet)
 		if !added {
 			t.Errorf("Expected VoteSet.Add to succeed, called SetPeerMaj23().")
@@ -346,7 +350,7 @@ func TestConflicts(t *testing.T) {
 
 	// val0 votes again for blockHash1.
 	{
-		vote := withValidator(voteProto, privValidators[0].Address, 0)
+		vote := withValidator(voteProto, privValidators[0].GetAddress(), 0)
 		added, err := signAddVote(privValidators[0], withBlockHash(vote, blockHash2), voteSet)
 		if added {
 			t.Errorf("Expected VoteSet.Add to fail, duplicate SetPeerMaj23() from peerA")
@@ -358,7 +362,7 @@ func TestConflicts(t *testing.T) {
 
 	// val1 votes for blockHash1.
 	{
-		vote := withValidator(voteProto, privValidators[1].Address, 1)
+		vote := withValidator(voteProto, privValidators[1].GetAddress(), 1)
 		added, err := signAddVote(privValidators[1], withBlockHash(vote, blockHash1), voteSet)
 		if !added || err != nil {
 			t.Errorf("Expected VoteSet.Add to succeed")
@@ -375,7 +379,7 @@ func TestConflicts(t *testing.T) {
 
 	// val2 votes for blockHash2.
 	{
-		vote := withValidator(voteProto, privValidators[2].Address, 2)
+		vote := withValidator(voteProto, privValidators[2].GetAddress(), 2)
 		added, err := signAddVote(privValidators[2], withBlockHash(vote, blockHash2), voteSet)
 		if !added || err != nil {
 			t.Errorf("Expected VoteSet.Add to succeed")
@@ -395,7 +399,7 @@ func TestConflicts(t *testing.T) {
 
 	// val2 votes for blockHash1.
 	{
-		vote := withValidator(voteProto, privValidators[2].Address, 2)
+		vote := withValidator(voteProto, privValidators[2].GetAddress(), 2)
 		added, err := signAddVote(privValidators[2], withBlockHash(vote, blockHash1), voteSet)
 		if !added {
 			t.Errorf("Expected VoteSet.Add to succeed")
@@ -435,7 +439,7 @@ func TestMakeCommit(t *testing.T) {
 
 	// 6 out of 10 voted for some block.
 	for i := 0; i < 6; i++ {
-		vote := withValidator(voteProto, privValidators[i].Address, i)
+		vote := withValidator(voteProto, privValidators[i].GetAddress(), i)
 		signAddVote(privValidators[i], vote, voteSet)
 	}
 
@@ -444,7 +448,7 @@ func TestMakeCommit(t *testing.T) {
 
 	// 7th voted for some other block.
 	{
-		vote := withValidator(voteProto, privValidators[6].Address, 6)
+		vote := withValidator(voteProto, privValidators[6].GetAddress(), 6)
 		vote = withBlockHash(vote, RandBytes(32))
 		vote = withBlockPartsHeader(vote, PartSetHeader{123, RandBytes(32)})
 		signAddVote(privValidators[6], vote, voteSet)
@@ -452,7 +456,7 @@ func TestMakeCommit(t *testing.T) {
 
 	// The 8th voted like everyone else.
 	{
-		vote := withValidator(voteProto, privValidators[7].Address, 7)
+		vote := withValidator(voteProto, privValidators[7].GetAddress(), 7)
 		signAddVote(privValidators[7], vote, voteSet)
 	}
 
diff --git a/version/version.go b/version/version.go
index 97dbbfa0e..504aee68b 100644
--- a/version/version.go
+++ b/version/version.go
@@ -1,12 +1,12 @@
 package version
 
 const Maj = "0"
-const Min = "10"
-const Fix = "4"
+const Min = "11"
+const Fix = "0"
 
 var (
 	// The full version string
-	Version = "0.10.4"
+	Version = "0.11.0"
 
 	// GitCommit is set with --ldflags "-X main.gitCommit=$(git rev-parse HEAD)"
 	GitCommit string