diff --git a/blockchain/reactor.go b/blockchain/reactor.go
index 0d51d124c..b39de838d 100644
--- a/blockchain/reactor.go
+++ b/blockchain/reactor.go
@@ -222,7 +222,7 @@ FOR_LOOP:
 					// We need both to sync the first block.
 					break SYNC_LOOP
 				}
-				firstParts := first.MakePartSet(types.DefaultPartSetSize)
+				firstParts := first.MakePartSet(types.DefaultBlockPartSize)
 				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
diff --git a/cmd/tendermint/commands/init.go b/cmd/tendermint/commands/init.go
index 75bc2bf95..bb8aa45dc 100644
--- a/cmd/tendermint/commands/init.go
+++ b/cmd/tendermint/commands/init.go
@@ -5,8 +5,8 @@ import (
 
 	"github.com/spf13/cobra"
 
-	cmn "github.com/tendermint/tmlibs/common"
 	"github.com/tendermint/tendermint/types"
+	cmn "github.com/tendermint/tmlibs/common"
 )
 
 var initFilesCmd = &cobra.Command{
@@ -20,13 +20,13 @@ func init() {
 }
 
 func initFiles(cmd *cobra.Command, args []string) {
-	privValFile := config.GetString("priv_validator_file")
+	privValFile := config.PrivValidatorFile
 	if _, err := os.Stat(privValFile); os.IsNotExist(err) {
 		privValidator := types.GenPrivValidator()
 		privValidator.SetFile(privValFile)
 		privValidator.Save()
 
-		genFile := config.GetString("genesis_file")
+		genFile := config.GenesisFile
 
 		if _, err := os.Stat(genFile); os.IsNotExist(err) {
 			genDoc := types.GenesisDoc{
@@ -40,8 +40,8 @@ func initFiles(cmd *cobra.Command, args []string) {
 			genDoc.SaveAs(genFile)
 		}
 
-		log.Notice("Initialized tendermint", "genesis", config.GetString("genesis_file"), "priv_validator", config.GetString("priv_validator_file"))
+		log.Notice("Initialized tendermint", "genesis", config.GenesisFile, "priv_validator", config.PrivValidatorFile)
 	} else {
-		log.Notice("Already initialized", "priv_validator", config.GetString("priv_validator_file"))
+		log.Notice("Already initialized", "priv_validator", config.PrivValidatorFile)
 	}
 }
diff --git a/cmd/tendermint/commands/replay.go b/cmd/tendermint/commands/replay.go
index 2f0e3266e..611a96a63 100644
--- a/cmd/tendermint/commands/replay.go
+++ b/cmd/tendermint/commands/replay.go
@@ -1,36 +1,26 @@
 package commands
 
 import (
-	"fmt"
+	"github.com/spf13/cobra"
 
 	"github.com/tendermint/tendermint/consensus"
-
-	"github.com/spf13/cobra"
 )
 
 var replayCmd = &cobra.Command{
-	Use:   "replay [walfile]",
+	Use:   "replay",
 	Short: "Replay messages from WAL",
 	Run: func(cmd *cobra.Command, args []string) {
-
-		if len(args) > 1 {
-			consensus.RunReplayFile(config, args[1], false)
-		} else {
-			fmt.Println("replay requires an argument (walfile)")
-		}
+		config := getConfig()
+		consensus.RunReplayFile(config.Config, config.Consensus, false)
 	},
 }
 
 var replayConsoleCmd = &cobra.Command{
-	Use:   "replay_console [walfile]",
+	Use:   "replay_console",
 	Short: "Replay messages from WAL in a console",
 	Run: func(cmd *cobra.Command, args []string) {
-
-		if len(args) > 1 {
-			consensus.RunReplayFile(config, args[1], true)
-		} else {
-			fmt.Println("replay_console requires an argument (walfile)")
-		}
+		config := getConfig()
+		consensus.RunReplayFile(config.Config, config.Consensus, true)
 	},
 }
 
diff --git a/cmd/tendermint/commands/reset_priv_validator.go b/cmd/tendermint/commands/reset_priv_validator.go
index 448a1869f..8f03c11d5 100644
--- a/cmd/tendermint/commands/reset_priv_validator.go
+++ b/cmd/tendermint/commands/reset_priv_validator.go
@@ -29,13 +29,15 @@ func init() {
 // XXX: this is totally unsafe.
 // it's only suitable for testnets.
 func resetAll(cmd *cobra.Command, args []string) {
-	ResetAll(config.GetString("db_dir"), config.GetString("priv_validator_file"), log)
+	config := getConfig()
+	ResetAll(config.DBDir, config.PrivValidatorFile, log)
 }
 
 // XXX: this is totally unsafe.
 // it's only suitable for testnets.
 func resetPrivValidator(cmd *cobra.Command, args []string) {
-	resetPrivValidatorLocal(config.GetString("priv_validator_file"), log)
+	config := getConfig()
+	resetPrivValidatorLocal(config.PrivValidatorFile, log)
 }
 
 // Exported so other CLI tools can use  it
diff --git a/cmd/tendermint/commands/root.go b/cmd/tendermint/commands/root.go
index 4a97c44fd..515ef9dc6 100644
--- a/cmd/tendermint/commands/root.go
+++ b/cmd/tendermint/commands/root.go
@@ -2,16 +2,34 @@ package commands
 
 import (
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 
-	tmcfg "github.com/tendermint/tendermint/config/tendermint"
+	"github.com/tendermint/tendermint/node"
 	"github.com/tendermint/tmlibs/logger"
 )
 
 var (
-	config = tmcfg.GetConfig("")
-	log    = logger.New("module", "main")
+	viperConfig *viper.Viper
+	config      *node.Config
+	log         = logger.New("module", "main")
 )
 
+func init() {
+	// Set config to be used as defaults by flags.
+	// This will be overwritten by whatever is unmarshalled from viper
+	config = node.NewDefaultConfig("")
+
+}
+
+// unmarshal viper into the Tendermint config
+func getConfig() *node.Config {
+	config := new(node.Config)
+	if err := viperConfig.Unmarshal(config); err != nil {
+		panic(err)
+	}
+	return config
+}
+
 //global flag
 var logLevel string
 
@@ -19,13 +37,14 @@ var RootCmd = &cobra.Command{
 	Use:   "tendermint",
 	Short: "Tendermint Core (BFT Consensus) in Go",
 	PersistentPreRun: func(cmd *cobra.Command, args []string) {
-		// set the log level in the config and logger
-		config.Set("node.log_level", logLevel)
-		logger.SetLogLevel(logLevel)
+		// set the log level
+		config := getConfig()
+		logger.SetLogLevel(config.LogLevel)
 	},
 }
 
 func init() {
 	//parse flag and set config
-	RootCmd.PersistentFlags().StringVar(&logLevel, "log_level", config.GetString("node.log_level"), "Log level")
+	RootCmd.PersistentFlags().StringVar(&logLevel, "log_level", config.LogLevel, "Log level")
+	viperConfig.BindPFlag("log_level", RootCmd.Flags().Lookup("log_level"))
 }
diff --git a/cmd/tendermint/commands/run_node.go b/cmd/tendermint/commands/run_node.go
index 2ddc50a02..c4d06efbf 100644
--- a/cmd/tendermint/commands/run_node.go
+++ b/cmd/tendermint/commands/run_node.go
@@ -14,10 +14,9 @@ import (
 )
 
 var runNodeCmd = &cobra.Command{
-	Use:    "node",
-	Short:  "Run the tendermint node",
-	PreRun: setConfigFlags,
-	RunE:   runNode,
+	Use:   "node",
+	Short: "Run the tendermint node",
+	RunE:  runNode,
 }
 
 //flags
@@ -35,49 +34,55 @@ var (
 )
 
 func init() {
+	// bind flags
 
-	// configuration options
-	runNodeCmd.Flags().StringVar(&moniker, "moniker", config.GetString("node.moniker"),
+	// node flags
+	runNodeCmd.Flags().StringVar(&moniker, "moniker", config.Moniker,
 		"Node Name")
-	runNodeCmd.Flags().StringVar(&nodeLaddr, "node_laddr", config.GetString("node.listen_addr"),
-		"Node listen address. (0.0.0.0:0 means any interface, any port)")
-	runNodeCmd.Flags().StringVar(&seeds, "seeds", config.GetString("network.seeds"),
-		"Comma delimited host:port seed nodes")
-	runNodeCmd.Flags().BoolVar(&fastSync, "fast_sync", config.GetBool("blockchain.fast_sync"),
+	viperConfig.BindPFlag("moniker", runNodeCmd.Flags().Lookup("moniker"))
+
+	runNodeCmd.Flags().BoolVar(&fastSync, "fast_sync", config.FastSync,
 		"Fast blockchain syncing")
-	runNodeCmd.Flags().BoolVar(&skipUPNP, "skip_upnp", config.GetBool("network.skip_upnp"),
-		"Skip UPNP configuration")
-	runNodeCmd.Flags().StringVar(&rpcLaddr, "rpc_laddr", config.GetString("rpc.listen_addr"),
-		"RPC listen address. Port required")
-	runNodeCmd.Flags().StringVar(&grpcLaddr, "grpc_laddr", config.GetString("grpc.listen_addr"),
-		"GRPC listen address (BroadcastTx only). Port required")
-	runNodeCmd.Flags().StringVar(&proxyApp, "proxy_app", config.GetString("abci.proxy_app"),
+	viperConfig.BindPFlag("fast_sync", runNodeCmd.Flags().Lookup("fast_sync"))
+
+	// abci flags
+	runNodeCmd.Flags().StringVar(&proxyApp, "proxy_app", config.ProxyApp,
 		"Proxy app address, or 'nilapp' or 'dummy' for local testing.")
-	runNodeCmd.Flags().StringVar(&abciTransport, "abci", config.GetString("abci.mode"),
+	viperConfig.BindPFlag("proxy_app", runNodeCmd.Flags().Lookup("proxy_app"))
+
+	runNodeCmd.Flags().StringVar(&abciTransport, "abci", config.ABCI,
 		"Specify abci transport (socket | grpc)")
+	viperConfig.BindPFlag("abci", runNodeCmd.Flags().Lookup("abci"))
+
+	// rpc flags
+	runNodeCmd.Flags().StringVar(&rpcLaddr, "rpc_laddr", config.RPCListenAddress,
+		"RPC listen address. Port required")
+	viperConfig.BindPFlag("rpc_laddr", runNodeCmd.Flags().Lookup("rpc_laddr"))
+
+	runNodeCmd.Flags().StringVar(&grpcLaddr, "grpc_laddr", config.GRPCListenAddress,
+		"GRPC listen address (BroadcastTx only). Port required")
+	viperConfig.BindPFlag("grpc_laddr", runNodeCmd.Flags().Lookup("grpc_laddr"))
+
+	// p2p flags
+	runNodeCmd.Flags().StringVar(&nodeLaddr, "p2p.laddr", config.P2P.ListenAddress,
+		"Node listen address. (0.0.0.0:0 means any interface, any port)")
+	viperConfig.BindPFlag("p2p.laddr", runNodeCmd.Flags().Lookup("p2p.laddr"))
+
+	runNodeCmd.Flags().StringVar(&seeds, "p2p.seeds", config.P2P.Seeds,
+		"Comma delimited host:port seed nodes")
+	viperConfig.BindPFlag("p2p.seeds", runNodeCmd.Flags().Lookup("p2p.seeds"))
+
+	runNodeCmd.Flags().BoolVar(&skipUPNP, "p2p.skip_upnp", config.P2P.SkipUPNP,
+		"Skip UPNP configuration")
+	viperConfig.BindPFlag("p2p.skip_upnp", runNodeCmd.Flags().Lookup("p2p.skip_upnp"))
 
 	// feature flags
-	runNodeCmd.Flags().BoolVar(&pex, "pex", config.GetBool("pex_reactor"),
+	runNodeCmd.Flags().BoolVar(&pex, "p2p.pex", config.P2P.PexReactor,
 		"Enable Peer-Exchange (dev feature)")
 
 	RootCmd.AddCommand(runNodeCmd)
 }
 
-func setConfigFlags(cmd *cobra.Command, args []string) {
-
-	// Merge parsed flag values onto config
-	config.Set("node.moniker", moniker)
-	config.Set("node.listen_addr", nodeLaddr)
-	config.Set("network.seeds", seeds)
-	config.Set("network.skip_upnp", skipUPNP)
-	config.Set("network.pex_reactor", pex)
-	config.Set("blockchain.fast_sync", fastSync)
-	config.Set("rpc.listen_addr", rpcLaddr)
-	config.Set("rpc.grpc_listen_addr", grpcLaddr)
-	config.Set("abci.proxy_app", proxyApp)
-	config.Set("abci.mode", abciTransport)
-}
-
 // Users wishing to:
 //	* Use an external signer for their validators
 //	* Supply an in-proc abci app
@@ -90,7 +95,7 @@ func runNode(cmd *cobra.Command, args []string) error {
 	// This is for Mintnet compatibility.
 	// TODO: If Mintnet gets deprecated or genesis_file is
 	// always available, remove.
-	genDocFile := config.GetString("genesis_file")
+	genDocFile := config.GenesisFile
 	if !cmn.FileExists(genDocFile) {
 		log.Notice(cmn.Fmt("Waiting for genesis file %v...", genDocFile))
 		for {
@@ -109,12 +114,13 @@ func runNode(cmd *cobra.Command, args []string) error {
 			if genDoc.ChainID == "" {
 				return fmt.Errorf("Genesis doc %v must include non-empty chain_id", genDocFile)
 			}
-			config.Set("chain_id", genDoc.ChainID)
+
+			// config.SetChainID("chain_id", genDoc.ChainID) TODO
 		}
 	}
 
 	// Create & start node
-	n := node.NewNodeDefault(config) //tmConfig)
+	n := node.NewNodeDefault(getConfig())
 	if _, err := n.Start(); err != nil {
 		return fmt.Errorf("Failed to start node: %v", err)
 	} else {
diff --git a/cmd/tendermint/commands/show_validator.go b/cmd/tendermint/commands/show_validator.go
index 951fd5a8c..16dfe1ff4 100644
--- a/cmd/tendermint/commands/show_validator.go
+++ b/cmd/tendermint/commands/show_validator.go
@@ -20,8 +20,8 @@ func init() {
 }
 
 func showValidator(cmd *cobra.Command, args []string) {
-	privValidatorFile := config.GetString("priv_validator_file")
-	privValidator := types.LoadOrGenPrivValidator(privValidatorFile)
+	config := getConfig()
+	privValidator := types.LoadOrGenPrivValidator(config.PrivValidatorFile)
 	pubKeyJSONBytes, _ := data.ToJSON(privValidator.PubKey)
 	fmt.Println(string(pubKeyJSONBytes))
 }
diff --git a/config/config.go b/config/config.go
new file mode 100644
index 000000000..5f4f28a83
--- /dev/null
+++ b/config/config.go
@@ -0,0 +1,73 @@
+package config
+
+// Config struct for a Tendermint node
+type Config struct {
+	// The ID of the chain to join (should be signed with every transaction and vote)
+	ChainID string `mapstructure:"chain_id"`
+
+	// A JSON file containing the initial validator set and other meta data
+	GenesisFile string `mapstructure:"genesis_file"`
+
+	// A JSON file containing the private key to use as a validator in the consensus protocol
+	PrivValidatorFile string `mapstructure:"priv_validator_file"`
+
+	// A custom human readable name for this node
+	Moniker string `mapstructure:"moniker"`
+
+	// TCP or UNIX socket address of the ABCI application,
+	// or the name of an ABCI application compiled in with the Tendermint binary
+	ProxyApp string `mapstructure:"proxy_app"`
+
+	// Mechanism to connect to the ABCI application: socket | grpc
+	ABCI string `mapstructure:"abci"`
+
+	// Output level for logging
+	LogLevel string `mapstructure:"log_level"`
+
+	// TCP or UNIX socket address for the profiling server to listen on
+	ProfListenAddress string `mapstructure:"prof_laddr"`
+
+	// If this node is many blocks behind the tip of the chain, FastSync
+	// allows them to catchup quickly by downloading blocks in parallel
+	// and verifying their commits
+	FastSync bool `mapstructure:"fast_sync"`
+
+	// If true, query the ABCI app on connecting to a new peer
+	// so the app can decide if we should keep the connection or not
+	FilterPeers bool `mapstructure:"filter_peers"` // false
+
+	// What indexer to use for transactions
+	TxIndex string `mapstructure:"tx_index"`
+
+	// Database backend: leveldb | memdb
+	DBBackend string `mapstructure:"db_backend"`
+
+	// Database directory
+	DBDir string `mapstructure:"db_dir"`
+
+	// TCP or UNIX socket address for the RPC server to listen on
+	RPCListenAddress string `mapstructure:"rpc_laddr"`
+
+	// TCP or UNIX socket address for the gRPC server to listen on
+	// NOTE: This server only supports /broadcast_tx_commit
+	GRPCListenAddress string `mapstructure:"grpc_laddr"`
+}
+
+func NewDefaultConfig(rootDir string) *Config {
+	return &Config{
+		GenesisFile:       rootDir + "/genesis.json",
+		PrivValidatorFile: rootDir + "/priv_validator.json",
+		Moniker:           "anonymous",
+		ProxyApp:          "tcp://127.0.0.1:46658",
+		ABCI:              "socket",
+		LogLevel:          "info",
+		ProfListenAddress: "",
+		FastSync:          true,
+		FilterPeers:       false,
+		TxIndex:           "kv",
+		DBBackend:         "leveldb",
+		DBDir:             rootDir + "/data",
+		RPCListenAddress:  "tcp://0.0.0.0:46657",
+		GRPCListenAddress: "",
+	}
+}
diff --git a/config/tendermint/types.go b/config/tendermint/types.go
deleted file mode 100644
index 7f0d421d8..000000000
--- a/config/tendermint/types.go
+++ /dev/null
@@ -1,89 +0,0 @@
-package tendermint
-
-type Config struct {
-	Node       NodeConfig       `mapstructure:"node"`
-	Chain      ChainConfig      `mapstructure:"chain"`
-	ABCI       ABCIConfig       `mapstructure:"abci"`
-	Network    NetworkConfig    `mapstructure:"network"`
-	Blockchain BlockchainConfig `mapstructure:"blockchain"`
-	Consensus  ConsensusConfig  `mapstructure:"consensus"`
-	Block      BlockConfig      `mapstructure:"block"`
-	Mempool    MempoolConfig    `mapstructure:"mempool"`
-	RPC        RPCConfig        `mapstructure:"rpc"`
-	DB         DBConfig         `mapstructure:"db"`
-}
-
-type NodeConfig struct {
-	Moniker           string `mapstructure:"moniker"`             // "anonymous"
-	PrivValidatorFile string `mapstructure:"priv_validator_file"` // rootDir+"/priv_validator.json")
-
-	LogLevel       string `mapstructure:"log_level"`  // info
-	ProfListenAddr string `mapstructure:"prof_laddr"` // ""
-}
-
-type ChainConfig struct {
-	ChainID     string `mapstructure:"chain_id"`
-	GenesisFile string `mapstructure:"genesis_file"` // rootDir/genesis.json
-}
-
-type ABCIConfig struct {
-	ProxyApp string `mapstructure:"proxy_app"` //  tcp://0.0.0.0:46658
-	Mode     string `mapstructure:"mode"`      // socket
-
-	FilterPeers bool `mapstructure:"filter_peers"` // false
-}
-
-type NetworkConfig struct {
-	ListenAddr     string `mapstructure:"listen_adddr"` // "tcp://0.0.0.0:46656")
-	Seeds          string `mapstructure:"seeds"`        // []string ...
-	SkipUPNP       bool   `mapstructure:"skip_upnp"`
-	AddrBookFile   string `mapstructure:"addr_book_file"`   // rootDir+"/addrbook.json")
-	AddrBookString bool   `mapstructure:"addr_book_string"` // true
-	PexReactor     bool   `mapstructure:"pex_reactor"`      // false
-}
-
-type BlockchainConfig struct {
-	FastSync bool `mapstructure:"fast_sync"` // true
-}
-
-type ConsensusConfig struct {
-	WalFile  string `mapstructure:"wal_file"`  //rootDir+"/data/cs.wal/wal")
-	WalLight bool   `mapstructure:"wal_light"` // false
-
-	// all timeouts are in ms
-	TimeoutPropose        int `mapstructure:"timeout_propose"`         // 3000
-	TimeoutProposeDelta   int `mapstructure:"timeout_propose_delta"`   // 500
-	TimeoutPrevote        int `mapstructure:"timeout_prevote"`         // 1000
-	TimeoutPrevoteDelta   int `mapstructure:"timeout_prevote_delta"`   // 500
-	TimeoutPrecommit      int `mapstructure:"timeout_precommit"`       // 1000
-	TimeoutPrecommitDelta int `mapstructure:"timeout_precommit_delta"` // 500
-	TimeoutCommit         int `mapstructure:"timeout_commit"`          // 1000
-
-	// make progress asap (no `timeout_commit`) on full precommit votes
-	SkipTimeoutCommit bool `mapstructure:"skip_timeout_commit"` // false
-}
-
-type BlockConfig struct {
-	MaxTxs          int  `mapstructure:"max_txs"`           // 10000
-	PartSize        int  `mapstructure:"part_size"`         // 65536
-	DisableDataHash bool `mapstructure:"disable_data_hash"` // false
-}
-
-type MempoolConfig struct {
-	Recheck      bool   `mapstructure:"recheck"`       // true
-	RecheckEmpty bool   `mapstructure:"recheck_empty"` // true
-	Broadcast    bool   `mapstructure:"broadcast"`     // true
-	WalDir       string `mapstructure:"wal_dir"`       // rootDir+"/data/mempool.wal")
-}
-
-type RPCConfig struct {
-	RPCListenAddress  string `mapstructure:"rpc_listen_addr"`  // "tcp://0.0.0.0:46657")
-	GRPCListenAddress string `mapstructure:"grpc_listen_addr"` // ""
-}
-
-type DBConfig struct {
-	Backend string `mapstructure:"backend"` // leveldb
-	Dir     string `mapstructure:"dir"`     // rootDir/data
-
-	TxIndex string `mapstructure:"tx_index"` // "kv"
-}
diff --git a/consensus/common_test.go b/consensus/common_test.go
index 1443232a6..7ebef78e9 100644
--- a/consensus/common_test.go
+++ b/consensus/common_test.go
@@ -28,6 +28,7 @@ import (
 	"github.com/tendermint/abci/example/dummy"
 )
 
+// genesis, chain_id, priv_val
 var config *viper.Viper // NOTE: must be reset for each _test.go file
 var ensureTimeout = time.Duration(2)
 
diff --git a/consensus/replay_file.go b/consensus/replay_file.go
index 1f4de893a..4e0f40b65 100644
--- a/consensus/replay_file.go
+++ b/consensus/replay_file.go
@@ -8,9 +8,8 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/spf13/viper"
-
 	bc "github.com/tendermint/tendermint/blockchain"
+	cfg "github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/proxy"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/types"
@@ -21,10 +20,10 @@ import (
 //--------------------------------------------------------
 // replay messages interactively or all at once
 
-func RunReplayFile(config *viper.Viper, walFile string, console bool) {
-	consensusState := newConsensusStateForReplay(config)
+func RunReplayFile(config *cfg.Config, csConfig *Config, console bool) {
+	consensusState := newConsensusStateForReplay(config, csConfig)
 
-	if err := consensusState.ReplayFile(walFile, console); err != nil {
+	if err := consensusState.ReplayFile(csConfig.WalFile, console); err != nil {
 		cmn.Exit(cmn.Fmt("Error during consensus replay: %v", err))
 	}
 }
@@ -236,33 +235,30 @@ func (pb *playback) replayConsoleLoop() int {
 //--------------------------------------------------------------------------------
 
 // convenience for replay mode
-func newConsensusStateForReplay(config *viper.Viper) *ConsensusState {
+func newConsensusStateForReplay(config *cfg.Config, csConfig *Config) *ConsensusState {
 	// Get BlockStore
-	blockStoreDB := dbm.NewDB("blockstore", config.GetString("db_backend"), config.GetString("db_dir"))
+	blockStoreDB := dbm.NewDB("blockstore", config.DBBackend, config.DBDir)
 	blockStore := bc.NewBlockStore(blockStoreDB)
 
 	// Get State
-	stateDB := dbm.NewDB("state", config.GetString("db_backend"), config.GetString("db_dir"))
-	state := sm.MakeGenesisStateFromFile(stateDB, config.GetString("genesis_file"))
+	stateDB := dbm.NewDB("state", config.DBBackend, config.DBDir)
+	state := sm.MakeGenesisStateFromFile(stateDB, config.GenesisFile)
 
 	// Create proxyAppConn connection (consensus, mempool, query)
-	clientCreator := proxy.DefaultClientCreator(config.GetString("proxy_app"), config.GetString("abci"), config.GetString("db_dir"))
+	clientCreator := proxy.DefaultClientCreator(config.ProxyApp, config.ABCI, config.DBDir)
 	proxyApp := proxy.NewAppConns(clientCreator, NewHandshaker(state, blockStore))
 	_, err := proxyApp.Start()
 	if err != nil {
 		cmn.Exit(cmn.Fmt("Error starting proxy app conns: %v", err))
 	}
 
-	// add the chainid to the global config
-	config.Set("chain_id", state.ChainID)
-
 	// Make event switch
 	eventSwitch := types.NewEventSwitch()
 	if _, err := eventSwitch.Start(); err != nil {
 		cmn.Exit(cmn.Fmt("Failed to start event switch: %v", err))
 	}
 
-	consensusState := NewConsensusState(config, state.Copy(), proxyApp.Consensus(), blockStore, types.MockMempool{})
+	consensusState := NewConsensusState(csConfig, state.Copy(), proxyApp.Consensus(), blockStore, types.MockMempool{})
 	consensusState.SetEventSwitch(eventSwitch)
 	return consensusState
 }
diff --git a/consensus/state.go b/consensus/state.go
index 28836a079..a77e8a669 100644
--- a/consensus/state.go
+++ b/consensus/state.go
@@ -10,7 +10,6 @@ import (
 	"time"
 
 	"github.com/ebuchman/fail-test"
-	"github.com/spf13/viper"
 
 	"github.com/tendermint/go-wire"
 	"github.com/tendermint/tendermint/proxy"
@@ -20,53 +19,90 @@ import (
 )
 
 //-----------------------------------------------------------------------------
-// Timeout Parameters
-
-// TimeoutParams holds timeouts and deltas for each round step.
-// All timeouts and deltas in milliseconds.
-type TimeoutParams struct {
-	Propose0          int
-	ProposeDelta      int
-	Prevote0          int
-	PrevoteDelta      int
-	Precommit0        int
-	PrecommitDelta    int
-	Commit0           int
-	SkipTimeoutCommit bool
+// Config
+
+// Config holds timeouts and details about the WAL, the block structure,
+// and timeouts in the consensus protocol.
+type Config struct {
+	WalFile  string `mapstructure:"wal_file"`
+	WalLight bool   `mapstructure:"wal_light"`
+
+	// All timeouts are in ms
+	TimeoutPropose        int `mapstructure:"timeout_propose"`
+	TimeoutProposeDelta   int `mapstructure:"timeout_propose_delta"`
+	TimeoutPrevote        int `mapstructure:"timeout_prevote"`
+	TimeoutPrevoteDelta   int `mapstructure:"timeout_prevote_delta"`
+	TimeoutPrecommit      int `mapstructure:"timeout_precommit"`
+	TimeoutPrecommitDelta int `mapstructure:"timeout_precommit_delta"`
+	TimeoutCommit         int `mapstructure:"timeout_commit"`
+
+	// Make progress as soon as we have all the precommits (as if TimeoutCommit = 0)
+	SkipTimeoutCommit bool `mapstructure:"skip_timeout_commit"`
+
+	// BlockSize
+	MaxBlockSizeTxs   int `mapstructure:"block_size_txs"`
+	MaxBlockSizeBytes int `mapstructure:"block_size_bytes"`
+
+	// 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"`
+
+	chainID string
+}
+
+func NewDefaultConfig(rootDir string) *Config {
+	return &Config{
+		WalFile:               rootDir + "/data/cs.wal/wal",
+		WalLight:              false,
+		TimeoutPropose:        3000,
+		TimeoutProposeDelta:   500,
+		TimeoutPrevote:        1000,
+		TimeoutPrevoteDelta:   500,
+		TimeoutPrecommit:      1000,
+		TimeoutPrecommitDelta: 500,
+		TimeoutCommit:         1000,
+		SkipTimeoutCommit:     false,
+		MaxBlockSizeTxs:       10000,
+		MaxBlockSizeBytes:     1, // TODO
+		BlockPartSize:         types.DefaultBlockPartSize,
+	}
+}
+
+func NewTestConfig(rootDir string) *Config {
+	config := NewDefaultConfig(rootDir)
+	config.TimeoutPropose = 2000
+	config.TimeoutProposeDelta = 1
+	config.TimeoutPrevote = 10
+	config.TimeoutPrevoteDelta = 1
+	config.TimeoutPrecommit = 10
+	config.TimeoutPrecommitDelta = 1
+	config.TimeoutCommit = 10
+	config.SkipTimeoutCommit = true
+	return config
+}
+
+func (cfg *Config) SetChainID(chainID string) {
+	cfg.chainID = chainID
 }
 
 // Wait this long for a proposal
-func (tp *TimeoutParams) Propose(round int) time.Duration {
-	return time.Duration(tp.Propose0+tp.ProposeDelta*round) * time.Millisecond
+func (cfg *Config) Propose(round int) time.Duration {
+	return time.Duration(cfg.TimeoutPropose+cfg.TimeoutProposeDelta*round) * time.Millisecond
 }
 
 // After receiving any +2/3 prevote, wait this long for stragglers
-func (tp *TimeoutParams) Prevote(round int) time.Duration {
-	return time.Duration(tp.Prevote0+tp.PrevoteDelta*round) * time.Millisecond
+func (cfg *Config) Prevote(round int) time.Duration {
+	return time.Duration(cfg.TimeoutPrevote+cfg.TimeoutPrevoteDelta*round) * time.Millisecond
 }
 
 // After receiving any +2/3 precommits, wait this long for stragglers
-func (tp *TimeoutParams) Precommit(round int) time.Duration {
-	return time.Duration(tp.Precommit0+tp.PrecommitDelta*round) * time.Millisecond
+func (cfg *Config) Precommit(round int) time.Duration {
+	return time.Duration(cfg.TimeoutPrecommit+cfg.TimeoutPrecommitDelta*round) * time.Millisecond
 }
 
 // After receiving +2/3 precommits for a single block (a commit), wait this long for stragglers in the next height's RoundStepNewHeight
-func (tp *TimeoutParams) Commit(t time.Time) time.Time {
-	return t.Add(time.Duration(tp.Commit0) * time.Millisecond)
-}
-
-// InitTimeoutParamsFromConfig initializes parameters from config
-func InitTimeoutParamsFromConfig(config *viper.Viper) *TimeoutParams {
-	return &TimeoutParams{
-		Propose0:          config.GetInt("timeout_propose"),
-		ProposeDelta:      config.GetInt("timeout_propose_delta"),
-		Prevote0:          config.GetInt("timeout_prevote"),
-		PrevoteDelta:      config.GetInt("timeout_prevote_delta"),
-		Precommit0:        config.GetInt("timeout_precommit"),
-		PrecommitDelta:    config.GetInt("timeout_precommit_delta"),
-		Commit0:           config.GetInt("timeout_commit"),
-		SkipTimeoutCommit: config.GetBool("skip_timeout_commit"),
-	}
+func (cfg *Config) Commit(t time.Time) time.Time {
+	return t.Add(time.Duration(cfg.TimeoutCommit) * time.Millisecond)
 }
 
 //-----------------------------------------------------------------------------
@@ -224,38 +260,48 @@ type PrivValidator interface {
 type ConsensusState struct {
 	cmn.BaseService
 
-	config       *viper.Viper
+	// config details
+	config        *Config
+	privValidator PrivValidator // for signing votes
+
+	// services for creating and executing blocks
 	proxyAppConn proxy.AppConnConsensus
 	blockStore   types.BlockStore
 	mempool      types.Mempool
 
-	privValidator PrivValidator // for signing votes
-
+	// internal state
 	mtx sync.Mutex
 	RoundState
 	state *sm.State // State until height-1.
 
-	peerMsgQueue     chan msgInfo   // serializes msgs affecting state (proposals, block parts, votes)
-	internalMsgQueue chan msgInfo   // like peerMsgQueue but for our own proposals, parts, votes
-	timeoutTicker    TimeoutTicker  // ticker for timeouts
-	timeoutParams    *TimeoutParams // parameters and functions for timeout intervals
+	// state changes may be triggered by msgs from peers,
+	// msgs from ourself, or by timeouts
+	peerMsgQueue     chan msgInfo
+	internalMsgQueue chan msgInfo
+	timeoutTicker    TimeoutTicker
 
+	// we use PubSub to trigger msg broadcasts in the reactor,
+	// and to notify external subscribers, eg. through a websocket
 	evsw types.EventSwitch
 
+	// a Write-Ahead Log ensures we can recover from any kind of crash
+	// and helps us avoid signing conflicting votes
 	wal        *WAL
 	replayMode bool // so we don't log signing errors during replay
 
-	nSteps int // used for testing to limit the number of transitions the state makes
+	// for tests where we want to limit the number of transitions the state makes
+	nSteps int
 
-	// allow certain function to be overwritten for testing
+	// some functions can be overwritten for testing
 	decideProposal func(height, round int)
 	doPrevote      func(height, round int)
 	setProposal    func(proposal *types.Proposal) error
 
+	// closed when we finish shutting down
 	done chan struct{}
 }
 
-func NewConsensusState(config *viper.Viper, state *sm.State, proxyAppConn proxy.AppConnConsensus, blockStore types.BlockStore, mempool types.Mempool) *ConsensusState {
+func NewConsensusState(config *Config, state *sm.State, proxyAppConn proxy.AppConnConsensus, blockStore types.BlockStore, mempool types.Mempool) *ConsensusState {
 	cs := &ConsensusState{
 		config:           config,
 		proxyAppConn:     proxyAppConn,
@@ -264,7 +310,6 @@ func NewConsensusState(config *viper.Viper, state *sm.State, proxyAppConn proxy.
 		peerMsgQueue:     make(chan msgInfo, msgQueueSize),
 		internalMsgQueue: make(chan msgInfo, msgQueueSize),
 		timeoutTicker:    NewTimeoutTicker(),
-		timeoutParams:    InitTimeoutParamsFromConfig(config),
 		done:             make(chan struct{}),
 	}
 	// set function defaults (may be overwritten before calling Start)
@@ -341,7 +386,7 @@ func (cs *ConsensusState) LoadCommit(height int) *types.Commit {
 
 func (cs *ConsensusState) OnStart() error {
 
-	walFile := cs.config.GetString("cs_wal_file")
+	walFile := cs.config.WalFile
 	if err := cs.OpenWAL(walFile); err != nil {
 		log.Error("Error loading ConsensusState wal", "error", err.Error())
 		return err
@@ -406,7 +451,7 @@ func (cs *ConsensusState) OpenWAL(walFile string) (err error) {
 
 	cs.mtx.Lock()
 	defer cs.mtx.Unlock()
-	wal, err := NewWAL(walFile, cs.config.GetBool("cs_wal_light"))
+	wal, err := NewWAL(walFile, cs.config.WalLight)
 	if err != nil {
 		return err
 	}
@@ -512,7 +557,7 @@ func (cs *ConsensusState) reconstructLastCommit(state *sm.State) {
 		return
 	}
 	seenCommit := cs.blockStore.LoadSeenCommit(state.LastBlockHeight)
-	lastPrecommits := types.NewVoteSet(cs.config.GetString("chain_id"), state.LastBlockHeight, seenCommit.Round(), types.VoteTypePrecommit, state.LastValidators)
+	lastPrecommits := types.NewVoteSet(cs.config.chainID, state.LastBlockHeight, seenCommit.Round(), types.VoteTypePrecommit, state.LastValidators)
 	for _, precommit := range seenCommit.Precommits {
 		if precommit == nil {
 			continue
@@ -572,9 +617,9 @@ func (cs *ConsensusState) updateToState(state *sm.State) {
 		// to be gathered for the first block.
 		// And alternative solution that relies on clocks:
 		//  cs.StartTime = state.LastBlockTime.Add(timeoutCommit)
-		cs.StartTime = cs.timeoutParams.Commit(time.Now())
+		cs.StartTime = cs.config.Commit(time.Now())
 	} else {
-		cs.StartTime = cs.timeoutParams.Commit(cs.CommitTime)
+		cs.StartTime = cs.config.Commit(cs.CommitTime)
 	}
 	cs.Validators = validators
 	cs.Proposal = nil
@@ -583,7 +628,7 @@ func (cs *ConsensusState) updateToState(state *sm.State) {
 	cs.LockedRound = 0
 	cs.LockedBlock = nil
 	cs.LockedBlockParts = nil
-	cs.Votes = NewHeightVoteSet(cs.config.GetString("chain_id"), height, validators)
+	cs.Votes = NewHeightVoteSet(cs.config.chainID, height, validators)
 	cs.CommitRound = -1
 	cs.LastCommit = lastPrecommits
 	cs.LastValidators = state.LastValidators
@@ -799,7 +844,7 @@ func (cs *ConsensusState) enterPropose(height int, round int) {
 	}()
 
 	// If we don't get the proposal and all block parts quick enough, enterPrevote
-	cs.scheduleTimeout(cs.timeoutParams.Propose(round), height, round, RoundStepPropose)
+	cs.scheduleTimeout(cs.config.Propose(round), height, round, RoundStepPropose)
 
 	// Nothing more to do if we're not a validator
 	if cs.privValidator == nil {
@@ -893,10 +938,10 @@ func (cs *ConsensusState) createProposalBlock() (block *types.Block, blockParts
 	}
 
 	// Mempool validated transactions
-	txs := cs.mempool.Reap(cs.config.GetInt("block_size"))
+	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.GetInt("block_part_size"))
+		cs.state.LastBlockID, cs.state.Validators.Hash(), cs.state.AppHash, cs.config.BlockPartSize)
 }
 
 // Enter: `timeoutPropose` after entering Propose.
@@ -982,7 +1027,7 @@ func (cs *ConsensusState) enterPrevoteWait(height int, round int) {
 	}()
 
 	// Wait for some more prevotes; enterPrecommit
-	cs.scheduleTimeout(cs.timeoutParams.Prevote(round), height, round, RoundStepPrevoteWait)
+	cs.scheduleTimeout(cs.config.Prevote(round), height, round, RoundStepPrevoteWait)
 }
 
 // Enter: +2/3 precomits for block or nil.
@@ -1102,7 +1147,7 @@ func (cs *ConsensusState) enterPrecommitWait(height int, round int) {
 	}()
 
 	// Wait for some more precommits; enterNewRound
-	cs.scheduleTimeout(cs.timeoutParams.Precommit(round), height, round, RoundStepPrecommitWait)
+	cs.scheduleTimeout(cs.config.Precommit(round), height, round, RoundStepPrecommitWait)
 
 }
 
@@ -1397,7 +1442,7 @@ func (cs *ConsensusState) addVote(vote *types.Vote, peerKey string) (added bool,
 			types.FireEventVote(cs.evsw, types.EventDataVote{vote})
 
 			// if we can skip timeoutCommit and have all the votes now,
-			if cs.timeoutParams.SkipTimeoutCommit && cs.LastCommit.HasAll() {
+			if cs.config.SkipTimeoutCommit && cs.LastCommit.HasAll() {
 				// go straight to new round (skip timeout commit)
 				// cs.scheduleTimeout(time.Duration(0), cs.Height, 0, RoundStepNewHeight)
 				cs.enterNewRound(cs.Height, 0)
@@ -1460,7 +1505,7 @@ func (cs *ConsensusState) addVote(vote *types.Vote, peerKey string) (added bool,
 						cs.enterPrecommit(height, vote.Round)
 						cs.enterCommit(height, vote.Round)
 
-						if cs.timeoutParams.SkipTimeoutCommit && precommits.HasAll() {
+						if cs.config.SkipTimeoutCommit && precommits.HasAll() {
 							// if we have all the votes now,
 							// go straight to new round (skip timeout commit)
 							// cs.scheduleTimeout(time.Duration(0), cs.Height, 0, RoundStepNewHeight)
diff --git a/mempool/mempool.go b/mempool/mempool.go
index 46a78d268..daf9f6524 100644
--- a/mempool/mempool.go
+++ b/mempool/mempool.go
@@ -47,7 +47,7 @@ TODO: Better handle abci client errors. (make it automatically handle connection
 const cacheSize = 100000
 
 type Mempool struct {
-	config Config
+	config *Config
 
 	proxyMtx      sync.Mutex
 	proxyAppConn  proxy.AppConnMempool
@@ -66,7 +66,7 @@ type Mempool struct {
 	wal *auto.AutoFile
 }
 
-func NewMempool(config Config, proxyAppConn proxy.AppConnMempool) *Mempool {
+func NewMempool(config *Config, proxyAppConn proxy.AppConnMempool) *Mempool {
 	mempool := &Mempool{
 		config:        config,
 		proxyAppConn:  proxyAppConn,
diff --git a/mempool/reactor.go b/mempool/reactor.go
index 3f25cc562..a0e7d518c 100644
--- a/mempool/reactor.go
+++ b/mempool/reactor.go
@@ -22,21 +22,30 @@ const (
 )
 
 type Config struct {
-	Recheck      bool   // true
-	RecheckEmpty bool   // true
-	Broadcast    bool   // true
-	WalDir       string // rootDir+"/data/mempool.wal")
+	Recheck      bool   `mapstructure:"recheck"`       // true
+	RecheckEmpty bool   `mapstructure:"recheck_empty"` // true
+	Broadcast    bool   `mapstructure:"broadcast"`     // true
+	WalDir       string `mapstructure:"wal_dir"`       //
+}
+
+func NewDefaultConfig(rootDir string) *Config {
+	return &Config{
+		Recheck:      true,
+		RecheckEmpty: true,
+		Broadcast:    true,
+		WalDir:       rootDir + "/data/mempool.wal",
+	}
 }
 
 // MempoolReactor handles mempool tx broadcasting amongst peers.
 type MempoolReactor struct {
 	p2p.BaseReactor
-	config  Config
+	config  *Config
 	Mempool *Mempool
 	evsw    types.EventSwitch
 }
 
-func NewMempoolReactor(config Config, mempool *Mempool) *MempoolReactor {
+func NewMempoolReactor(config *Config, mempool *Mempool) *MempoolReactor {
 	memR := &MempoolReactor{
 		config:  config,
 		Mempool: mempool,
diff --git a/node/node.go b/node/node.go
index c4000a1fe..742c9984c 100644
--- a/node/node.go
+++ b/node/node.go
@@ -13,7 +13,8 @@ import (
 	crypto "github.com/tendermint/go-crypto"
 	wire "github.com/tendermint/go-wire"
 	bc "github.com/tendermint/tendermint/blockchain"
-	tmcfg "github.com/tendermint/tendermint/config/tendermint"
+	cfg "github.com/tendermint/tendermint/config"
+	// tmcfg "github.com/tendermint/tendermint/config/tendermint"
 	"github.com/tendermint/tendermint/consensus"
 	mempl "github.com/tendermint/tendermint/mempool"
 	p2p "github.com/tendermint/tendermint/p2p"
@@ -34,11 +35,30 @@ import (
 	_ "net/http/pprof"
 )
 
+type Config struct {
+	// Top level options use an anonymous struct
+	*cfg.Config `mapstructure:",squash"`
+
+	// Options for services
+	P2P       *p2p.NetworkConfig `mapstructure:"p2p"`
+	Mempool   *mempl.Config      `mapstructure:"mempool"`
+	Consensus *consensus.Config  `mapstructure:"consensus"`
+}
+
+func NewDefaultConfig(rootDir string) *Config {
+	return &Config{
+		Config:    cfg.NewDefaultConfig(rootDir),
+		P2P:       p2p.NewDefaultConfig(rootDir),
+		Mempool:   mempl.NewDefaultConfig(rootDir),
+		Consensus: consensus.NewDefaultConfig(rootDir),
+	}
+}
+
 type Node struct {
 	cmn.BaseService
 
 	// config
-	config        *viper.Viper         // user config
+	config        *Config
 	genesisDoc    *types.GenesisDoc    // initial validator set
 	privValidator *types.PrivValidator // local node's validator key
 
@@ -59,35 +79,27 @@ type Node struct {
 	txIndexer        txindex.TxIndexer
 }
 
-func NewNodeDefault(config *viper.Viper) *Node {
+func NewNodeDefault(config *Config) *Node {
 	// Get PrivValidator
-	privValidatorFile := config.GetString("priv_validator_file")
-	privValidator := types.LoadOrGenPrivValidator(privValidatorFile)
-	return NewNode(config, privValidator, proxy.DefaultClientCreator(
-		config.GetString("proxy_app"),
-		config.GetString("abci"),
-		config.GetString("db_dir"),
-	))
-	// config.ABCI.ProxyApp, config.ABCI.Mode, config.DB.Dir))
+	privValidator := types.LoadOrGenPrivValidator(config.PrivValidatorFile)
+	return NewNode(config, privValidator,
+		proxy.DefaultClientCreator(config.ProxyApp, config.ABCI, config.DBDir))
 }
 
-func NewNode(config *viper.Viper, privValidator *types.PrivValidator, clientCreator proxy.ClientCreator) *Node {
-
-	tmConfig := new(tmcfg.Config)
-	if err := config.Unmarshal(tmConfig); err != nil {
-		panic(err)
-	}
+func NewNode(config *Config, privValidator *types.PrivValidator, clientCreator proxy.ClientCreator) *Node {
 
 	// Get BlockStore
-	blockStoreDB := dbm.NewDB("blockstore", tmConfig.DB.Backend, tmConfig.DB.Dir)
+	blockStoreDB := dbm.NewDB("blockstore", config.DBBackend, config.DBDir)
 	blockStore := bc.NewBlockStore(blockStoreDB)
 
 	// Get State
-	stateDB := dbm.NewDB("state", tmConfig.DB.Backend, tmConfig.DB.Dir)
-	state := sm.GetState(stateDB, tmConfig.Chain.GenesisFile)
+	stateDB := dbm.NewDB("state", config.DBBackend, config.DBDir)
+	state := sm.GetState(stateDB, config.GenesisFile)
 
 	// add the chainid and number of validators to the global config
-	config.Set("chain_id", state.ChainID)
+	// TODO: Set ChainID. eg:
+	// config.Consensus.SetChainID(state.ChainID) // ...
+	// but actually consensus doesnt need it since the cs has the state ...
 
 	// Create the proxyApp, which manages connections (consensus, mempool, query)
 	// and sync tendermint and the app by replaying any necessary blocks
@@ -101,9 +113,9 @@ func NewNode(config *viper.Viper, privValidator *types.PrivValidator, clientCrea
 
 	// Transaction indexing
 	var txIndexer txindex.TxIndexer
-	switch tmConfig.DB.TxIndex {
+	switch config.TxIndex {
 	case "kv":
-		store := dbm.NewDB("tx_index", tmConfig.DB.Backend, tmConfig.DB.Dir)
+		store := dbm.NewDB("tx_index", config.DBBackend, config.DBDir)
 		txIndexer = kv.NewTxIndex(store)
 	default:
 		txIndexer = &null.TxIndex{}
@@ -122,7 +134,7 @@ func NewNode(config *viper.Viper, privValidator *types.PrivValidator, clientCrea
 
 	// Decide whether to fast-sync or not
 	// We don't fast-sync when the only validator is us.
-	fastSync := config.GetBool("fast_sync")
+	fastSync := config.FastSync
 	if state.Validators.Size() == 1 {
 		addr, _ := state.Validators.GetByIndex(0)
 		if bytes.Equal(privValidator.Address, addr) {
@@ -134,21 +146,20 @@ func NewNode(config *viper.Viper, privValidator *types.PrivValidator, clientCrea
 	bcReactor := bc.NewBlockchainReactor(state.Copy(), proxyApp.Consensus(), blockStore, fastSync)
 
 	// Make MempoolReactor
-	mempool := mempl.NewMempool(mempoolConfig(config), proxyApp.Mempool())
-	mempoolReactor := mempl.NewMempoolReactor(mempoolConfig(config), mempool)
+	mempool := mempl.NewMempool(config.Mempool, proxyApp.Mempool())
+	mempoolReactor := mempl.NewMempoolReactor(config.Mempool, mempool)
 
 	// Make ConsensusReactor
-	consensusState := consensus.NewConsensusState(config, state.Copy(), proxyApp.Consensus(), blockStore, mempool)
+	consensusState := consensus.NewConsensusState(config.Consensus, state.Copy(), proxyApp.Consensus(), blockStore, mempool)
 	if privValidator != nil {
 		consensusState.SetPrivValidator(privValidator)
 	}
 	consensusReactor := consensus.NewConsensusReactor(consensusState, fastSync)
 
 	// Make p2p network switch
+	// TODO  : p2pConfig := config.P2P
 	p2pConfig := viper.New()
-	if config.IsSet("p2p") { //TODO verify this necessary, where is this ever set?
-		p2pConfig = config.Get("p2p").(*viper.Viper)
-	}
+
 	sw := p2p.NewSwitch(p2pConfig)
 	sw.AddReactor("MEMPOOL", mempoolReactor)
 	sw.AddReactor("BLOCKCHAIN", bcReactor)
@@ -156,8 +167,8 @@ func NewNode(config *viper.Viper, privValidator *types.PrivValidator, clientCrea
 
 	// Optionally, start the pex reactor
 	var addrBook *p2p.AddrBook
-	if config.GetBool("pex_reactor") {
-		addrBook = p2p.NewAddrBook(config.GetString("addrbook_file"), config.GetBool("addrbook_strict"))
+	if config.P2P.PexReactor {
+		addrBook = p2p.NewAddrBook(config.P2P.AddrBookFile, config.P2P.AddrBookStrict)
 		pexReactor := p2p.NewPEXReactor(addrBook)
 		sw.AddReactor("PEX", pexReactor)
 	}
@@ -165,7 +176,7 @@ func NewNode(config *viper.Viper, privValidator *types.PrivValidator, clientCrea
 	// Filter peers by addr or pubkey with an ABCI query.
 	// If the query return code is OK, add peer.
 	// XXX: Query format subject to change
-	if config.GetBool("filter_peers") {
+	if config.FilterPeers {
 		// NOTE: addr is ip:port
 		sw.SetAddrFilter(func(addr net.Addr) error {
 			resQuery, err := proxyApp.Query().QuerySync(abci.RequestQuery{Path: cmn.Fmt("/p2p/filter/addr/%s", addr.String())})
@@ -194,7 +205,7 @@ func NewNode(config *viper.Viper, privValidator *types.PrivValidator, clientCrea
 	SetEventSwitch(eventSwitch, bcReactor, mempoolReactor, consensusReactor)
 
 	// run the profile server
-	profileHost := config.GetString("prof_laddr")
+	profileHost := config.ProfListenAddress
 	if profileHost != "" {
 
 		go func() {
@@ -227,8 +238,8 @@ func NewNode(config *viper.Viper, privValidator *types.PrivValidator, clientCrea
 func (n *Node) OnStart() error {
 
 	// Create & add listener
-	protocol, address := ProtocolAndAddress(n.config.GetString("node_laddr"))
-	l := p2p.NewDefaultListener(protocol, address, n.config.GetBool("skip_upnp"))
+	protocol, address := ProtocolAndAddress(n.config.P2P.ListenAddress)
+	l := p2p.NewDefaultListener(protocol, address, n.config.P2P.SkipUPNP)
 	n.sw.AddListener(l)
 
 	// Start the switch
@@ -240,16 +251,16 @@ func (n *Node) OnStart() error {
 	}
 
 	// If seeds exist, add them to the address book and dial out
-	if n.config.GetString("seeds") != "" {
+	if n.config.P2P.Seeds != "" {
 		// dial out
-		seeds := strings.Split(n.config.GetString("seeds"), ",")
+		seeds := strings.Split(n.config.P2P.Seeds, ",")
 		if err := n.DialSeeds(seeds); err != nil {
 			return err
 		}
 	}
 
 	// Run the RPC server
-	if n.config.GetString("rpc_laddr") != "" {
+	if n.config.RPCListenAddress != "" {
 		listeners, err := n.startRPC()
 		if err != nil {
 			return err
@@ -313,7 +324,7 @@ func (n *Node) ConfigureRPC() {
 
 func (n *Node) startRPC() ([]net.Listener, error) {
 	n.ConfigureRPC()
-	listenAddrs := strings.Split(n.config.GetString("rpc_laddr"), ",")
+	listenAddrs := strings.Split(n.config.RPCListenAddress, ",")
 
 	// we may expose the rpc over both a unix and tcp socket
 	listeners := make([]net.Listener, len(listenAddrs))
@@ -330,7 +341,7 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 	}
 
 	// we expose a simplified api over grpc for convenience to app devs
-	grpcListenAddr := n.config.GetString("grpc_laddr")
+	grpcListenAddr := n.config.GRPCListenAddress
 	if grpcListenAddr != "" {
 		listener, err := grpccore.StartGRPCServer(grpcListenAddr)
 		if err != nil {
@@ -387,8 +398,8 @@ func (n *Node) makeNodeInfo() *p2p.NodeInfo {
 
 	nodeInfo := &p2p.NodeInfo{
 		PubKey:  n.privKey.PubKey().Unwrap().(crypto.PubKeyEd25519),
-		Moniker: n.config.GetString("moniker"),
-		Network: n.config.GetString("chain_id"),
+		Moniker: n.config.Moniker,
+		Network: n.consensusState.GetState().ChainID,
 		Version: version.Version,
 		Other: []string{
 			cmn.Fmt("wire_version=%v", wire.Version),
@@ -400,9 +411,10 @@ func (n *Node) makeNodeInfo() *p2p.NodeInfo {
 	}
 
 	// include git hash in the nodeInfo if available
-	if rev, err := cmn.ReadFile(n.config.GetString("revision_file")); err == nil {
+	// TODO: use ld-flags
+	/*if rev, err := cmn.ReadFile(n.config.GetString("revision_file")); err == nil {
 		nodeInfo.Other = append(nodeInfo.Other, cmn.Fmt("revision=%v", string(rev)))
-	}
+	}*/
 
 	if !n.sw.IsListening() {
 		return nodeInfo
@@ -411,7 +423,7 @@ func (n *Node) makeNodeInfo() *p2p.NodeInfo {
 	p2pListener := n.sw.Listeners()[0]
 	p2pHost := p2pListener.ExternalAddress().IP.String()
 	p2pPort := p2pListener.ExternalAddress().Port
-	rpcListenAddr := n.config.GetString("rpc_laddr")
+	rpcListenAddr := n.config.RPCListenAddress
 
 	// We assume that the rpcListener has the same ExternalAddress.
 	// This is probably true because both P2P and RPC listeners use UPnP,
@@ -442,12 +454,3 @@ func ProtocolAndAddress(listenAddr string) (string, string) {
 }
 
 //------------------------------------------------------------------------------
-
-func mempoolConfig(config *viper.Viper) mempl.Config {
-	return mempl.Config{
-		Recheck:      config.GetBool("mempool_recheck"),
-		RecheckEmpty: config.GetBool("mempool_recheck_empty"),
-		Broadcast:    config.GetBool("mempool_broadcast"),
-		WalDir:       config.GetString("mempool_wal_dir"),
-	}
-}
diff --git a/p2p/config.go b/p2p/config.go
index 2e70d16df..4eccd4be7 100644
--- a/p2p/config.go
+++ b/p2p/config.go
@@ -4,6 +4,23 @@ import (
 	"github.com/spf13/viper"
 )
 
+// for node.Config
+type NetworkConfig struct {
+	ListenAddress  string `mapstructure:"laddr"`
+	Seeds          string `mapstructure:"seeds"`
+	SkipUPNP       bool   `mapstructure:"skip_upnp"`
+	AddrBookFile   string `mapstructure:"addr_book_file"`
+	AddrBookStrict bool   `mapstructure:"addr_book_strict"`
+	PexReactor     bool   `mapstructure:"pex_reactor"`
+}
+
+func NewDefaultConfig(rootDir string) *NetworkConfig {
+	return &NetworkConfig{
+		AddrBookFile:   rootDir + "/addrbook.json",
+		AddrBookStrict: true,
+	}
+}
+
 const (
 	// Switch config keys
 	configKeyDialTimeoutSeconds      = "dial_timeout_seconds"
diff --git a/types/block.go b/types/block.go
index afa3be4e7..0f0fc75b6 100644
--- a/types/block.go
+++ b/types/block.go
@@ -15,8 +15,8 @@ import (
 )
 
 const (
-	MaxBlockSize       = 22020096 // 21MB TODO make it configurable
-	DefaultPartSetSize = 65536    // 64kB TODO: put part size in parts header?
+	MaxBlockSize         = 22020096 // 21MB TODO make it configurable
+	DefaultBlockPartSize = 65536    // 64kB TODO: put part size in parts header?
 )
 
 type Block struct {