diff --git a/blockchain/log.go b/blockchain/log.go
new file mode 100644
index 000000000..f04e99943
--- /dev/null
+++ b/blockchain/log.go
@@ -0,0 +1,7 @@
+package blockchain
+
+import (
+	"github.com/tendermint/tendermint/logger"
+)
+
+var log = logger.New("module", "blockchain")
diff --git a/blockchain/pool.go b/blockchain/pool.go
new file mode 100644
index 000000000..528c66548
--- /dev/null
+++ b/blockchain/pool.go
@@ -0,0 +1,354 @@
+package blockchain
+
+import (
+	"math/rand"
+	"sync/atomic"
+	"time"
+
+	. "github.com/tendermint/tendermint/common"
+	"github.com/tendermint/tendermint/types"
+)
+
+const (
+	maxOutstandingRequestsPerPeer = 10
+	eventsChannelCapacity         = 100
+	requestTimeoutSeconds         = 10
+	maxTries                      = 3
+	requestIntervalMS             = 500
+	requestBatchSize              = 50
+	maxPendingRequests            = 50
+	maxTotalRequests              = 100
+	maxPeersPerRequest            = 1
+)
+
+type BlockRequest struct {
+	Height uint
+	PeerId string
+}
+
+type BlockPool struct {
+	peers      map[string]*bpPeer
+	blockInfos map[uint]*bpBlockInfo
+	height     uint  // the lowest key in blockInfos.
+	started    int32 // atomic
+	stopped    int32 // atomic
+	numPending int32
+	numTotal   int32
+	eventsCh   chan interface{}    // internal events.
+	requestsCh chan<- BlockRequest // output of new requests to make.
+	timeoutsCh chan<- string       // output of peers that timed out.
+	blocksCh   chan<- *types.Block // output of ordered blocks.
+	repeater   *RepeatTimer        // for requesting more bocks.
+	quit       chan struct{}
+}
+
+func NewBlockPool(start uint, timeoutsCh chan<- string, requestsCh chan<- BlockRequest, blocksCh chan<- *types.Block) *BlockPool {
+	return &BlockPool{
+		peers:      make(map[string]*bpPeer),
+		blockInfos: make(map[uint]*bpBlockInfo),
+		height:     start,
+		started:    0,
+		stopped:    0,
+		numPending: 0,
+		numTotal:   0,
+		quit:       make(chan struct{}),
+
+		eventsCh:   make(chan interface{}, eventsChannelCapacity),
+		requestsCh: requestsCh,
+		timeoutsCh: timeoutsCh,
+		blocksCh:   blocksCh,
+		repeater:   NewRepeatTimer("", requestIntervalMS*time.Millisecond),
+	}
+}
+
+func (bp *BlockPool) Start() {
+	if atomic.CompareAndSwapInt32(&bp.started, 0, 1) {
+		log.Info("Starting BlockPool")
+		go bp.run()
+	}
+}
+
+func (bp *BlockPool) Stop() {
+	if atomic.CompareAndSwapInt32(&bp.stopped, 0, 1) {
+		log.Info("Stopping BlockPool")
+		close(bp.quit)
+		close(bp.eventsCh)
+		close(bp.requestsCh)
+		close(bp.timeoutsCh)
+		close(bp.blocksCh)
+		bp.repeater.Stop()
+	}
+}
+
+// AddBlock should be called when a block is received.
+func (bp *BlockPool) AddBlock(block *types.Block, peerId string) {
+	bp.eventsCh <- bpBlockResponse{block, peerId}
+}
+
+func (bp *BlockPool) SetPeerStatus(peerId string, height uint) {
+	bp.eventsCh <- bpPeerStatus{peerId, height}
+}
+
+// Runs in a goroutine and processes messages.
+func (bp *BlockPool) run() {
+FOR_LOOP:
+	for {
+		select {
+		case msg := <-bp.eventsCh:
+			bp.handleEvent(msg)
+		case <-bp.repeater.Ch:
+			bp.makeMoreBlockInfos()
+			bp.requestBlocksFromRandomPeers(10)
+		case <-bp.quit:
+			break FOR_LOOP
+		}
+	}
+}
+
+func (bp *BlockPool) handleEvent(event_ interface{}) {
+	switch event := event_.(type) {
+	case bpBlockResponse:
+		peer := bp.peers[event.peerId]
+		blockInfo := bp.blockInfos[event.block.Height]
+		if blockInfo == nil {
+			// block was unwanted.
+			if peer != nil {
+				peer.bad++
+			}
+		} else {
+			// block was wanted.
+			if peer != nil {
+				peer.good++
+			}
+			delete(peer.requests, event.block.Height)
+			if blockInfo.block == nil {
+				// peer is the first to give it to us.
+				blockInfo.block = event.block
+				blockInfo.blockBy = peer.id
+				bp.numPending--
+				if event.block.Height == bp.height {
+					go bp.pushBlocksFromStart()
+				}
+			}
+		}
+	case bpPeerStatus: // updated or new status from peer
+		// request blocks if possible.
+		peer := bp.peers[event.peerId]
+		if peer == nil {
+			peer = bpNewPeer(event.peerId, event.height)
+			bp.peers[peer.id] = peer
+		}
+		bp.requestBlocksFromPeer(peer)
+	case bpRequestTimeout: // unconditional timeout for each peer's request.
+		peer := bp.peers[event.peerId]
+		if peer == nil {
+			// cleanup was already handled.
+			return
+		}
+		height := event.height
+		request := peer.requests[height]
+		if request == nil || request.block != nil {
+			// the request was fulfilled by some peer or this peer.
+			return
+		}
+
+		// A request for peer timed out.
+		peer.bad++
+		if request.tries < maxTries {
+			log.Warn("Timeout: Trying again.", "tries", request.tries, "peerId", peer.id)
+			// try again.
+			select {
+			case bp.requestsCh <- BlockRequest{height, peer.id}:
+				request.startAndTimeoutTo(bp.eventsCh) // also bumps request.tries
+			default:
+				// The request cannot be made because requestCh is full.
+				// Just delete the request.
+				delete(peer.requests, height)
+			}
+		} else {
+			log.Warn("Timeout: Deleting request")
+			// delete the request.
+			delete(peer.requests, height)
+			blockInfo := bp.blockInfos[height]
+			if blockInfo != nil {
+				delete(blockInfo.requests, peer.id)
+			}
+			select {
+			case bp.timeoutsCh <- peer.id:
+			default:
+			}
+
+		}
+	}
+}
+
+// NOTE: This function is sufficient, but we should find pending blocks
+// and sample the peers in one go rather than the current O(n^2) impl.
+func (bp *BlockPool) requestBlocksFromRandomPeers(maxPeers int) {
+	chosen := bp.pickAvailablePeers(maxPeers)
+	log.Debug("requestBlocksFromRandomPeers", "chosen", len(chosen))
+	for _, peer := range chosen {
+		bp.requestBlocksFromPeer(peer)
+	}
+}
+
+func (bp *BlockPool) requestBlocksFromPeer(peer *bpPeer) {
+	// If peer is available and can provide something...
+	for height := bp.height; peer.available(); height++ {
+		blockInfo := bp.blockInfos[height]
+		if blockInfo == nil {
+			// We're out of range.
+			return
+		}
+		needsMorePeers := blockInfo.needsMorePeers()
+		alreadyAskedPeer := blockInfo.requests[peer.id] != nil
+		if needsMorePeers && !alreadyAskedPeer {
+			select {
+			case bp.requestsCh <- BlockRequest{height, peer.id}:
+				// Create a new request and start the timer.
+				request := &bpBlockRequest{
+					height: height,
+					peer:   peer,
+				}
+				blockInfo.requests[peer.id] = request
+				peer.requests[height] = request
+				request.startAndTimeoutTo(bp.eventsCh) // also bumps request.tries
+			default:
+				// The request cannot be made because requestCh is full.
+				// Just stop.
+				return
+			}
+		}
+	}
+}
+
+func (bp *BlockPool) makeMoreBlockInfos() {
+	// make more requests if necessary.
+	for i := 0; i < requestBatchSize; i++ {
+		//log.Debug("Confused?",
+		//    "numPending", bp.numPending, "maxPendingRequests", maxPendingRequests, "numtotal", bp.numTotal, "maxTotalRequests", maxTotalRequests)
+		if bp.numPending < maxPendingRequests && bp.numTotal < maxTotalRequests {
+			// Make a request for the next block height
+			requestHeight := bp.height + uint(bp.numTotal)
+			log.Debug("New blockInfo", "height", requestHeight)
+			blockInfo := bpNewBlockInfo(requestHeight)
+			bp.blockInfos[requestHeight] = blockInfo
+			bp.numPending++
+			bp.numTotal++
+		} else {
+			break
+		}
+	}
+}
+
+func (bp *BlockPool) pickAvailablePeers(choose int) []*bpPeer {
+	available := []*bpPeer{}
+	for _, peer := range bp.peers {
+		if peer.available() {
+			available = append(available, peer)
+		}
+	}
+	perm := rand.Perm(MinInt(choose, len(available)))
+	chosen := make([]*bpPeer, len(perm))
+	for i, idx := range perm {
+		chosen[i] = available[idx]
+	}
+	return chosen
+}
+
+// blocking
+func (bp *BlockPool) pushBlocksFromStart() {
+	for height := bp.height; ; height++ {
+		// push block to blocksCh.
+		blockInfo := bp.blockInfos[height]
+		if blockInfo == nil || blockInfo.block == nil {
+			break
+		}
+		bp.numTotal--
+		bp.height++
+		delete(bp.blockInfos, height)
+		bp.blocksCh <- blockInfo.block
+	}
+}
+
+//-----------------------------------------------------------------------------
+
+type bpBlockInfo struct {
+	height   uint
+	requests map[string]*bpBlockRequest
+	block    *types.Block // first block received
+	blockBy  string       // peerId of source
+}
+
+func bpNewBlockInfo(height uint) *bpBlockInfo {
+	return &bpBlockInfo{
+		height:   height,
+		requests: make(map[string]*bpBlockRequest),
+	}
+}
+
+func (blockInfo *bpBlockInfo) needsMorePeers() bool {
+	return len(blockInfo.requests) < maxPeersPerRequest
+}
+
+//-------------------------------------
+
+type bpBlockRequest struct {
+	peer   *bpPeer
+	height uint
+	block  *types.Block
+	tries  int
+}
+
+// bump tries++ and set timeout.
+// NOTE: the timer is unconditional.
+func (request *bpBlockRequest) startAndTimeoutTo(eventsCh chan<- interface{}) {
+	request.tries++
+	time.AfterFunc(requestTimeoutSeconds*time.Second, func() {
+		eventsCh <- bpRequestTimeout{
+			peerId: request.peer.id,
+			height: request.height,
+		}
+	})
+}
+
+//-------------------------------------
+
+type bpPeer struct {
+	id       string
+	height   uint
+	requests map[uint]*bpBlockRequest
+	// Count good/bad events from peer.
+	good uint
+	bad  uint
+}
+
+func bpNewPeer(peerId string, height uint) *bpPeer {
+	return &bpPeer{
+		id:       peerId,
+		height:   height,
+		requests: make(map[uint]*bpBlockRequest),
+	}
+}
+
+func (peer *bpPeer) available() bool {
+	return len(peer.requests) < maxOutstandingRequestsPerPeer
+}
+
+//-------------------------------------
+// bp.eventsCh messages
+
+type bpBlockResponse struct {
+	block  *types.Block
+	peerId string
+}
+
+type bpPeerStatus struct {
+	peerId string
+	height uint // blockchain tip of peer
+}
+
+type bpRequestTimeout struct {
+	peerId string
+	height uint
+}
diff --git a/blockchain/pool_test.go b/blockchain/pool_test.go
new file mode 100644
index 000000000..4376f3ac0
--- /dev/null
+++ b/blockchain/pool_test.go
@@ -0,0 +1,112 @@
+package blockchain
+
+import (
+	"math/rand"
+	"testing"
+
+	. "github.com/tendermint/tendermint/common"
+	"github.com/tendermint/tendermint/types"
+)
+
+type testPeer struct {
+	id     string
+	height uint
+}
+
+func makePeers(numPeers int, minHeight, maxHeight uint) map[string]testPeer {
+	peers := make(map[string]testPeer, numPeers)
+	for i := 0; i < numPeers; i++ {
+		peerId := RandStr(12)
+		height := minHeight + uint(rand.Intn(int(maxHeight-minHeight)))
+		peers[peerId] = testPeer{peerId, height}
+	}
+	return peers
+}
+
+func TestBasic(t *testing.T) {
+	// 100 peers anywhere at height 0 to 1000.
+	peers := makePeers(100, 0, 1000)
+
+	start := uint(42)
+	maxHeight := uint(300)
+	timeoutsCh := make(chan string, 100)
+	requestsCh := make(chan BlockRequest, 100)
+	blocksCh := make(chan *types.Block, 100)
+
+	pool := NewBlockPool(start, timeoutsCh, requestsCh, blocksCh)
+	pool.Start()
+
+	// Introduce each peer.
+	go func() {
+		for _, peer := range peers {
+			pool.SetPeerStatus(peer.id, peer.height)
+		}
+	}()
+
+	lastSeenBlock := uint(41)
+
+	// Pull from channels
+	for {
+		select {
+		case peerId := <-timeoutsCh:
+			t.Errorf("timeout: %v", peerId)
+		case request := <-requestsCh:
+			log.Debug("TEST: Pulled new BlockRequest", "request", request)
+			// After a while, pretend like we got a block from the peer.
+			go func() {
+				block := &types.Block{Header: &types.Header{Height: request.Height}}
+				pool.AddBlock(block, request.PeerId)
+				log.Debug("TEST: Added block", "block", request.Height, "peer", request.PeerId)
+			}()
+		case block := <-blocksCh:
+			log.Debug("TEST: Pulled new Block", "height", block.Height)
+			if block.Height != lastSeenBlock+1 {
+				t.Fatalf("Wrong order of blocks seen. Expected: %v Got: %v", lastSeenBlock+1, block.Height)
+			}
+			lastSeenBlock++
+			if block.Height == maxHeight {
+				return // Done!
+			}
+		}
+	}
+
+	pool.Stop()
+}
+
+func TestTimeout(t *testing.T) {
+	peers := makePeers(100, 0, 1000)
+	start := uint(42)
+	timeoutsCh := make(chan string, 10)
+	requestsCh := make(chan BlockRequest, 10)
+	blocksCh := make(chan *types.Block, 100)
+
+	pool := NewBlockPool(start, timeoutsCh, requestsCh, blocksCh)
+	pool.Start()
+
+	// Introduce each peer.
+	go func() {
+		for _, peer := range peers {
+			pool.SetPeerStatus(peer.id, peer.height)
+		}
+	}()
+
+	// Pull from channels
+	for {
+		select {
+		case peerId := <-timeoutsCh:
+			// Timed out. Done!
+			if peers[peerId].id != peerId {
+				t.Errorf("Unexpected peer from timeoutsCh")
+			}
+			return
+		case _ = <-requestsCh:
+			// Don't do anything, let it time out.
+		case _ = <-blocksCh:
+			t.Errorf("Got block when none expected")
+			return
+		}
+	}
+
+	pool.Stop()
+
+}
diff --git a/blockchain/store.go b/blockchain/store.go
new file mode 100644
index 000000000..8938273cb
--- /dev/null
+++ b/blockchain/store.go
@@ -0,0 +1,248 @@
+package blockchain
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/tendermint/tendermint/binary"
+	. "github.com/tendermint/tendermint/common"
+	dbm "github.com/tendermint/tendermint/db"
+	"github.com/tendermint/tendermint/types"
+)
+
+/*
+Simple low level store for blocks.
+
+There are three types of information stored:
+ - BlockMeta:   Meta information about each block
+ - Block part:  Parts of each block, aggregated w/ PartSet
+ - Validation:  The Validation part of each block, for gossiping commit votes
+
+Currently the commit signatures are duplicated in the Block parts as
+well as the Validation.  In the future this may change, perhaps by moving
+the Validation data outside the Block.
+*/
+type BlockStore struct {
+	height uint
+	db     dbm.DB
+}
+
+func NewBlockStore(db dbm.DB) *BlockStore {
+	bsjson := LoadBlockStoreStateJSON(db)
+	return &BlockStore{
+		height: bsjson.Height,
+		db:     db,
+	}
+}
+
+// Height() returns the last known contiguous block height.
+func (bs *BlockStore) Height() uint {
+	return bs.height
+}
+
+func (bs *BlockStore) GetReader(key []byte) io.Reader {
+	bytez := bs.db.Get(key)
+	if bytez == nil {
+		return nil
+	}
+	return bytes.NewReader(bytez)
+}
+
+func (bs *BlockStore) LoadBlock(height uint) *types.Block {
+	var n int64
+	var err error
+	r := bs.GetReader(calcBlockMetaKey(height))
+	if r == nil {
+		panic(Fmt("Block does not exist at height %v", height))
+	}
+	meta := binary.ReadBinary(&BlockMeta{}, r, &n, &err).(*BlockMeta)
+	if err != nil {
+		panic(Fmt("Error reading block meta: %v", err))
+	}
+	bytez := []byte{}
+	for i := uint(0); i < meta.Parts.Total; i++ {
+		part := bs.LoadBlockPart(height, i)
+		bytez = append(bytez, part.Bytes...)
+	}
+	block := binary.ReadBinary(&types.Block{}, bytes.NewReader(bytez), &n, &err).(*types.Block)
+	if err != nil {
+		panic(Fmt("Error reading block: %v", err))
+	}
+	return block
+}
+
+func (bs *BlockStore) LoadBlockPart(height uint, index uint) *types.Part {
+	var n int64
+	var err error
+	r := bs.GetReader(calcBlockPartKey(height, index))
+	if r == nil {
+		panic(Fmt("BlockPart does not exist for height %v index %v", height, index))
+	}
+	part := binary.ReadBinary(&types.Part{}, r, &n, &err).(*types.Part)
+	if err != nil {
+		panic(Fmt("Error reading block part: %v", err))
+	}
+	return part
+}
+
+func (bs *BlockStore) LoadBlockMeta(height uint) *BlockMeta {
+	var n int64
+	var err error
+	r := bs.GetReader(calcBlockMetaKey(height))
+	if r == nil {
+		panic(Fmt("BlockMeta does not exist for height %v", height))
+	}
+	meta := binary.ReadBinary(&BlockMeta{}, r, &n, &err).(*BlockMeta)
+	if err != nil {
+		panic(Fmt("Error reading block meta: %v", err))
+	}
+	return meta
+}
+
+// NOTE: the Commit-vote heights are for the block at `height-1`
+// Since these are included in the subsequent block, the height
+// is off by 1.
+func (bs *BlockStore) LoadBlockValidation(height uint) *types.Validation {
+	var n int64
+	var err error
+	r := bs.GetReader(calcBlockValidationKey(height))
+	if r == nil {
+		panic(Fmt("BlockValidation does not exist for height %v", height))
+	}
+	validation := binary.ReadBinary(&types.Validation{}, r, &n, &err).(*types.Validation)
+	if err != nil {
+		panic(Fmt("Error reading validation: %v", err))
+	}
+	return validation
+}
+
+// NOTE: the Commit-vote heights are for the block at `height`
+func (bs *BlockStore) LoadSeenValidation(height uint) *types.Validation {
+	var n int64
+	var err error
+	r := bs.GetReader(calcSeenValidationKey(height))
+	if r == nil {
+		panic(Fmt("SeenValidation does not exist for height %v", height))
+	}
+	validation := binary.ReadBinary(&types.Validation{}, r, &n, &err).(*types.Validation)
+	if err != nil {
+		panic(Fmt("Error reading validation: %v", err))
+	}
+	return validation
+}
+
+// blockParts:     Must be parts of the block
+// seenValidation: The +2/3 commits that were seen which finalized the height.
+//                 If all the nodes restart after committing a block,
+//                 we need this to reload the commits to catch-up nodes to the
+//                 most recent height.  Otherwise they'd stall at H-1.
+//				   Also good to have to debug consensus issues & punish wrong-signers
+// 				   whose commits weren't included in the block.
+func (bs *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenValidation *types.Validation) {
+	height := block.Height
+	if height != bs.height+1 {
+		panic(Fmt("BlockStore can only save contiguous blocks. Wanted %v, got %v", bs.height+1, height))
+	}
+	if !blockParts.IsComplete() {
+		panic(Fmt("BlockStore can only save complete block part sets"))
+	}
+
+	// Save block meta
+	meta := makeBlockMeta(block, blockParts)
+	metaBytes := binary.BinaryBytes(meta)
+	bs.db.Set(calcBlockMetaKey(height), metaBytes)
+
+	// Save block parts
+	for i := uint(0); i < blockParts.Total(); i++ {
+		bs.saveBlockPart(height, i, blockParts.GetPart(i))
+	}
+
+	// Save block validation (duplicate and separate from the Block)
+	blockValidationBytes := binary.BinaryBytes(block.Validation)
+	bs.db.Set(calcBlockValidationKey(height), blockValidationBytes)
+
+	// Save seen validation (seen +2/3 commits)
+	seenValidationBytes := binary.BinaryBytes(seenValidation)
+	bs.db.Set(calcSeenValidationKey(height), seenValidationBytes)
+
+	// Save new BlockStoreStateJSON descriptor
+	BlockStoreStateJSON{Height: height}.Save(bs.db)
+
+	// Done!
+	bs.height = height
+}
+
+func (bs *BlockStore) saveBlockPart(height uint, index uint, part *types.Part) {
+	if height != bs.height+1 {
+		panic(Fmt("BlockStore can only save contiguous blocks. Wanted %v, got %v", bs.height+1, height))
+	}
+	partBytes := binary.BinaryBytes(part)
+	bs.db.Set(calcBlockPartKey(height, index), partBytes)
+}
+
+//-----------------------------------------------------------------------------
+
+type BlockMeta struct {
+	Hash   []byte              // The block hash
+	Header *types.Header       // The block's Header
+	Parts  types.PartSetHeader // The PartSetHeader, for transfer
+}
+
+func makeBlockMeta(block *types.Block, blockParts *types.PartSet) *BlockMeta {
+	return &BlockMeta{
+		Hash:   block.Hash(),
+		Header: block.Header,
+		Parts:  blockParts.Header(),
+	}
+}
+
+//-----------------------------------------------------------------------------
+
+func calcBlockMetaKey(height uint) []byte {
+	return []byte(fmt.Sprintf("H:%v", height))
+}
+
+func calcBlockPartKey(height uint, partIndex uint) []byte {
+	return []byte(fmt.Sprintf("P:%v:%v", height, partIndex))
+}
+
+func calcBlockValidationKey(height uint) []byte {
+	return []byte(fmt.Sprintf("V:%v", height))
+}
+
+func calcSeenValidationKey(height uint) []byte {
+	return []byte(fmt.Sprintf("SV:%v", height))
+}
+
+//-----------------------------------------------------------------------------
+
+var blockStoreKey = []byte("blockStore")
+
+type BlockStoreStateJSON struct {
+	Height uint
+}
+
+func (bsj BlockStoreStateJSON) Save(db dbm.DB) {
+	bytes, err := json.Marshal(bsj)
+	if err != nil {
+		panic(Fmt("Could not marshal state bytes: %v", err))
+	}
+	db.Set(blockStoreKey, bytes)
+}
+
+func LoadBlockStoreStateJSON(db dbm.DB) BlockStoreStateJSON {
+	bytes := db.Get(blockStoreKey)
+	if bytes == nil {
+		return BlockStoreStateJSON{
+			Height: 0,
+		}
+	}
+	bsj := BlockStoreStateJSON{}
+	err := json.Unmarshal(bytes, &bsj)
+	if err != nil {
+		panic(Fmt("Could not unmarshal bytes: %X", bytes))
+	}
+	return bsj
+}
diff --git a/cmd/gen_tx.go b/cmd/gen_tx.go
index f1fe13ea3..687339bed 100644
--- a/cmd/gen_tx.go
+++ b/cmd/gen_tx.go
@@ -10,10 +10,10 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	dbm "github.com/tendermint/tendermint/db"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 func getString(prompt string) string {
@@ -80,9 +80,9 @@ func gen_tx() {
 	dstSendAmount := getUint64(Fmt("Enter amount to send to %X: ", dstAddress))
 
 	// Construct SendTx
-	tx := &blk.SendTx{
-		Inputs: []*blk.TxInput{
-			&blk.TxInput{
+	tx := &types.SendTx{
+		Inputs: []*types.TxInput{
+			&types.TxInput{
 				Address:   srcAddress,
 				Amount:    srcSendAmount,
 				Sequence:  srcSendSequence,
@@ -90,8 +90,8 @@ func gen_tx() {
 				PubKey:    srcPubKey,
 			},
 		},
-		Outputs: []*blk.TxOutput{
-			&blk.TxOutput{
+		Outputs: []*types.TxOutput{
+			&types.TxOutput{
 				Address: dstAddress,
 				Amount:  dstSendAmount,
 			},
diff --git a/consensus/pol.go b/consensus/pol.go
index 3483b2f1b..c87b4ee5d 100644
--- a/consensus/pol.go
+++ b/consensus/pol.go
@@ -4,9 +4,9 @@ import (
 	"fmt"
 
 	"github.com/tendermint/tendermint/account"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 // Each signature of a POL (proof-of-lock, see whitepaper) is
@@ -23,9 +23,9 @@ type POLVoteSignature struct {
 type POL struct {
 	Height     uint
 	Round      uint
-	BlockHash  []byte             // Could be nil, which makes this a proof of unlock.
-	BlockParts blk.PartSetHeader  // When BlockHash is nil, this is zero.
-	Votes      []POLVoteSignature // Prevote and commit signatures in ValidatorSet order.
+	BlockHash  []byte              // Could be nil, which makes this a proof of unlock.
+	BlockParts types.PartSetHeader // When BlockHash is nil, this is zero.
+	Votes      []POLVoteSignature  // Prevote and commit signatures in ValidatorSet order.
 }
 
 // Returns whether +2/3 have prevoted/committed for BlockHash.
@@ -37,8 +37,8 @@ func (pol *POL) Verify(valSet *sm.ValidatorSet) error {
 	}
 
 	talliedVotingPower := uint64(0)
-	prevoteDoc := account.SignBytes(&blk.Vote{
-		Height: pol.Height, Round: pol.Round, Type: blk.VoteTypePrevote,
+	prevoteDoc := account.SignBytes(&types.Vote{
+		Height: pol.Height, Round: pol.Round, Type: types.VoteTypePrevote,
 		BlockHash:  pol.BlockHash,
 		BlockParts: pol.BlockParts,
 	})
@@ -54,8 +54,8 @@ func (pol *POL) Verify(valSet *sm.ValidatorSet) error {
 
 		// Commit vote?
 		if vote.Round < pol.Round {
-			voteDoc = account.SignBytes(&blk.Vote{
-				Height: pol.Height, Round: vote.Round, Type: blk.VoteTypeCommit,
+			voteDoc = account.SignBytes(&types.Vote{
+				Height: pol.Height, Round: vote.Round, Type: types.VoteTypeCommit,
 				BlockHash:  pol.BlockHash,
 				BlockParts: pol.BlockParts,
 			})
diff --git a/consensus/pol_test.go b/consensus/pol_test.go
index 5420e0f44..e1d67e4dd 100644
--- a/consensus/pol_test.go
+++ b/consensus/pol_test.go
@@ -2,9 +2,9 @@ package consensus
 
 import (
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 
 	"bytes"
 	"testing"
@@ -15,7 +15,7 @@ import (
 // Convenience method.
 // Signs the vote and sets the POL's vote at the desired index
 // Returns the POLVoteSignature pointer, so you can modify it afterwards.
-func signAddPOLVoteSignature(val *sm.PrivValidator, valSet *sm.ValidatorSet, vote *blk.Vote, pol *POL) *POLVoteSignature {
+func signAddPOLVoteSignature(val *sm.PrivValidator, valSet *sm.ValidatorSet, vote *types.Vote, pol *POL) *POLVoteSignature {
 	vote = vote.Copy()
 	err := val.SignVote(vote)
 	if err != nil {
@@ -28,7 +28,7 @@ func signAddPOLVoteSignature(val *sm.PrivValidator, valSet *sm.ValidatorSet, vot
 
 func TestVerifyVotes(t *testing.T) {
 	height, round := uint(1), uint(0)
-	_, valSet, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	_, valSet, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// Make a POL with -2/3 votes.
 	blockHash := RandBytes(32)
@@ -36,8 +36,8 @@ func TestVerifyVotes(t *testing.T) {
 		Height: height, Round: round, BlockHash: blockHash,
 		Votes: make([]POLVoteSignature, valSet.Size()),
 	}
-	voteProto := &blk.Vote{
-		Height: height, Round: round, Type: blk.VoteTypePrevote, BlockHash: blockHash,
+	voteProto := &types.Vote{
+		Height: height, Round: round, Type: types.VoteTypePrevote, BlockHash: blockHash,
 	}
 	for i := 0; i < 6; i++ {
 		signAddPOLVoteSignature(privValidators[i], valSet, voteProto, pol)
@@ -59,7 +59,7 @@ func TestVerifyVotes(t *testing.T) {
 
 func TestVerifyInvalidVote(t *testing.T) {
 	height, round := uint(1), uint(0)
-	_, valSet, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	_, valSet, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// Make a POL with +2/3 votes with the wrong signature.
 	blockHash := RandBytes(32)
@@ -67,8 +67,8 @@ func TestVerifyInvalidVote(t *testing.T) {
 		Height: height, Round: round, BlockHash: blockHash,
 		Votes: make([]POLVoteSignature, valSet.Size()),
 	}
-	voteProto := &blk.Vote{
-		Height: height, Round: round, Type: blk.VoteTypePrevote, BlockHash: blockHash,
+	voteProto := &types.Vote{
+		Height: height, Round: round, Type: types.VoteTypePrevote, BlockHash: blockHash,
 	}
 	for i := 0; i < 7; i++ {
 		polVoteSig := signAddPOLVoteSignature(privValidators[i], valSet, voteProto, pol)
@@ -83,7 +83,7 @@ func TestVerifyInvalidVote(t *testing.T) {
 
 func TestVerifyCommits(t *testing.T) {
 	height, round := uint(1), uint(2)
-	_, valSet, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	_, valSet, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// Make a POL with +2/3 votes.
 	blockHash := RandBytes(32)
@@ -91,8 +91,8 @@ func TestVerifyCommits(t *testing.T) {
 		Height: height, Round: round, BlockHash: blockHash,
 		Votes: make([]POLVoteSignature, valSet.Size()),
 	}
-	voteProto := &blk.Vote{
-		Height: height, Round: round - 1, Type: blk.VoteTypeCommit, BlockHash: blockHash,
+	voteProto := &types.Vote{
+		Height: height, Round: round - 1, Type: types.VoteTypeCommit, BlockHash: blockHash,
 	}
 	for i := 0; i < 7; i++ {
 		signAddPOLVoteSignature(privValidators[i], valSet, voteProto, pol)
@@ -106,7 +106,7 @@ func TestVerifyCommits(t *testing.T) {
 
 func TestVerifyInvalidCommits(t *testing.T) {
 	height, round := uint(1), uint(2)
-	_, valSet, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	_, valSet, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// Make a POL with +2/3 votes with the wrong signature.
 	blockHash := RandBytes(32)
@@ -114,8 +114,8 @@ func TestVerifyInvalidCommits(t *testing.T) {
 		Height: height, Round: round, BlockHash: blockHash,
 		Votes: make([]POLVoteSignature, valSet.Size()),
 	}
-	voteProto := &blk.Vote{
-		Height: height, Round: round - 1, Type: blk.VoteTypeCommit, BlockHash: blockHash,
+	voteProto := &types.Vote{
+		Height: height, Round: round - 1, Type: types.VoteTypeCommit, BlockHash: blockHash,
 	}
 	for i := 0; i < 7; i++ {
 		polVoteSig := signAddPOLVoteSignature(privValidators[i], valSet, voteProto, pol)
@@ -130,7 +130,7 @@ func TestVerifyInvalidCommits(t *testing.T) {
 
 func TestVerifyInvalidCommitRounds(t *testing.T) {
 	height, round := uint(1), uint(2)
-	_, valSet, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	_, valSet, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// Make a POL with +2/3 commits for the current round.
 	blockHash := RandBytes(32)
@@ -138,8 +138,8 @@ func TestVerifyInvalidCommitRounds(t *testing.T) {
 		Height: height, Round: round, BlockHash: blockHash,
 		Votes: make([]POLVoteSignature, valSet.Size()),
 	}
-	voteProto := &blk.Vote{
-		Height: height, Round: round, Type: blk.VoteTypeCommit, BlockHash: blockHash,
+	voteProto := &types.Vote{
+		Height: height, Round: round, Type: types.VoteTypeCommit, BlockHash: blockHash,
 	}
 	for i := 0; i < 7; i++ {
 		signAddPOLVoteSignature(privValidators[i], valSet, voteProto, pol)
@@ -153,7 +153,7 @@ func TestVerifyInvalidCommitRounds(t *testing.T) {
 
 func TestVerifyInvalidCommitRounds2(t *testing.T) {
 	height, round := uint(1), uint(2)
-	_, valSet, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	_, valSet, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// Make a POL with +2/3 commits for future round.
 	blockHash := RandBytes(32)
@@ -161,8 +161,8 @@ func TestVerifyInvalidCommitRounds2(t *testing.T) {
 		Height: height, Round: round, BlockHash: blockHash,
 		Votes: make([]POLVoteSignature, valSet.Size()),
 	}
-	voteProto := &blk.Vote{
-		Height: height, Round: round + 1, Type: blk.VoteTypeCommit, BlockHash: blockHash,
+	voteProto := &types.Vote{
+		Height: height, Round: round + 1, Type: types.VoteTypeCommit, BlockHash: blockHash,
 	}
 	for i := 0; i < 7; i++ {
 		polVoteSig := signAddPOLVoteSignature(privValidators[i], valSet, voteProto, pol)
@@ -177,7 +177,7 @@ func TestVerifyInvalidCommitRounds2(t *testing.T) {
 
 func TestReadWrite(t *testing.T) {
 	height, round := uint(1), uint(2)
-	_, valSet, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	_, valSet, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// Make a POL with +2/3 votes.
 	blockHash := RandBytes(32)
@@ -185,8 +185,8 @@ func TestReadWrite(t *testing.T) {
 		Height: height, Round: round, BlockHash: blockHash,
 		Votes: make([]POLVoteSignature, valSet.Size()),
 	}
-	voteProto := &blk.Vote{
-		Height: height, Round: round, Type: blk.VoteTypePrevote, BlockHash: blockHash,
+	voteProto := &types.Vote{
+		Height: height, Round: round, Type: types.VoteTypePrevote, BlockHash: blockHash,
 	}
 	for i := 0; i < 7; i++ {
 		signAddPOLVoteSignature(privValidators[i], valSet, voteProto, pol)
diff --git a/consensus/reactor.go b/consensus/reactor.go
index 9b3f37de6..83c244995 100644
--- a/consensus/reactor.go
+++ b/consensus/reactor.go
@@ -9,11 +9,11 @@ import (
 	"time"
 
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	. "github.com/tendermint/tendermint/consensus/types"
 	"github.com/tendermint/tendermint/p2p"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 const (
@@ -34,11 +34,11 @@ type ConsensusReactor struct {
 	stopped uint32
 	quit    chan struct{}
 
-	blockStore *blk.BlockStore
+	blockStore *types.BlockStore
 	conS       *ConsensusState
 }
 
-func NewConsensusReactor(consensusState *ConsensusState, blockStore *blk.BlockStore) *ConsensusReactor {
+func NewConsensusReactor(consensusState *ConsensusState, blockStore *types.BlockStore) *ConsensusReactor {
 	conR := &ConsensusReactor{
 		blockStore: blockStore,
 		quit:       make(chan struct{}),
@@ -167,9 +167,9 @@ func (conR *ConsensusReactor) Receive(chId byte, peer *p2p.Peer, msgBytes []byte
 			added, index, err := conR.conS.AddVote(address, vote)
 			if err != nil {
 				// If conflicting sig, broadcast evidence tx for slashing. Else punish peer.
-				if errDupe, ok := err.(*blk.ErrVoteConflictingSignature); ok {
+				if errDupe, ok := err.(*types.ErrVoteConflictingSignature); ok {
 					log.Warn("Found conflicting vote. Publish evidence")
-					evidenceTx := &blk.DupeoutTx{
+					evidenceTx := &types.DupeoutTx{
 						Address: address,
 						VoteA:   *errDupe.VoteA,
 						VoteB:   *errDupe.VoteB,
@@ -404,7 +404,7 @@ OUTER_LOOP:
 			return false
 		}
 
-		trySendCommitFromValidation := func(blockMeta *blk.BlockMeta, validation *blk.Validation, peerVoteSet BitArray) (sent bool) {
+		trySendCommitFromValidation := func(blockMeta *types.BlockMeta, validation *types.Validation, peerVoteSet BitArray) (sent bool) {
 			// Initialize Commits if needed
 			ps.EnsureVoteBitArrays(prs.Height, uint(len(validation.Commits)))
 
@@ -412,10 +412,10 @@ OUTER_LOOP:
 				commit := validation.Commits[index]
 				log.Debug("Picked commit to send", "index", index, "commit", commit)
 				// Reconstruct vote.
-				vote := &blk.Vote{
+				vote := &types.Vote{
 					Height:     prs.Height,
 					Round:      commit.Round,
-					Type:       blk.VoteTypeCommit,
+					Type:       types.VoteTypeCommit,
 					BlockHash:  blockMeta.Hash,
 					BlockParts: blockMeta.Parts,
 					Signature:  commit.Signature,
@@ -515,20 +515,20 @@ OUTER_LOOP:
 
 // Read only when returned by PeerState.GetRoundState().
 type PeerRoundState struct {
-	Height                uint              // Height peer is at
-	Round                 uint              // Round peer is at
-	Step                  RoundStep         // Step peer is at
-	StartTime             time.Time         // Estimated start of round 0 at this height
-	Proposal              bool              // True if peer has proposal for this round
-	ProposalBlockParts    blk.PartSetHeader //
-	ProposalBlockBitArray BitArray          // True bit -> has part
-	ProposalPOLParts      blk.PartSetHeader //
-	ProposalPOLBitArray   BitArray          // True bit -> has part
-	Prevotes              BitArray          // All votes peer has for this round
-	Precommits            BitArray          // All precommits peer has for this round
-	Commits               BitArray          // All commits peer has for this height
-	LastCommits           BitArray          // All commits peer has for last height
-	HasAllCatchupCommits  bool              // Used for catch-up
+	Height                uint                // Height peer is at
+	Round                 uint                // Round peer is at
+	Step                  RoundStep           // Step peer is at
+	StartTime             time.Time           // Estimated start of round 0 at this height
+	Proposal              bool                // True if peer has proposal for this round
+	ProposalBlockParts    types.PartSetHeader //
+	ProposalBlockBitArray BitArray            // True bit -> has part
+	ProposalPOLParts      types.PartSetHeader //
+	ProposalPOLBitArray   BitArray            // True bit -> has part
+	Prevotes              BitArray            // All votes peer has for this round
+	Precommits            BitArray            // All precommits peer has for this round
+	Commits               BitArray            // All commits peer has for this height
+	LastCommits           BitArray            // All commits peer has for last height
+	HasAllCatchupCommits  bool                // Used for catch-up
 }
 
 //-----------------------------------------------------------------------------
@@ -616,7 +616,7 @@ func (ps *PeerState) EnsureVoteBitArrays(height uint, numValidators uint) {
 	}
 }
 
-func (ps *PeerState) SetHasVote(vote *blk.Vote, index uint) {
+func (ps *PeerState) SetHasVote(vote *types.Vote, index uint) {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()
 
@@ -624,7 +624,7 @@ func (ps *PeerState) SetHasVote(vote *blk.Vote, index uint) {
 }
 
 func (ps *PeerState) setHasVote(height uint, round uint, type_ byte, index uint) {
-	if ps.Height == height+1 && type_ == blk.VoteTypeCommit {
+	if ps.Height == height+1 && type_ == types.VoteTypeCommit {
 		// Special case for LastCommits.
 		ps.LastCommits.SetIndex(index, true)
 		return
@@ -634,11 +634,11 @@ func (ps *PeerState) setHasVote(height uint, round uint, type_ byte, index uint)
 	}
 
 	switch type_ {
-	case blk.VoteTypePrevote:
+	case types.VoteTypePrevote:
 		ps.Prevotes.SetIndex(index, true)
-	case blk.VoteTypePrecommit:
+	case types.VoteTypePrecommit:
 		ps.Precommits.SetIndex(index, true)
-	case blk.VoteTypeCommit:
+	case types.VoteTypeCommit:
 		if round < ps.Round {
 			ps.Prevotes.SetIndex(index, true)
 			ps.Precommits.SetIndex(index, true)
@@ -676,9 +676,9 @@ func (ps *PeerState) ApplyNewRoundStepMessage(msg *NewRoundStepMessage, rs *Roun
 	ps.StartTime = startTime
 	if psHeight != msg.Height || psRound != msg.Round {
 		ps.Proposal = false
-		ps.ProposalBlockParts = blk.PartSetHeader{}
+		ps.ProposalBlockParts = types.PartSetHeader{}
 		ps.ProposalBlockBitArray = BitArray{}
-		ps.ProposalPOLParts = blk.PartSetHeader{}
+		ps.ProposalPOLParts = types.PartSetHeader{}
 		ps.ProposalPOLBitArray = BitArray{}
 		// We'll update the BitArray capacity later.
 		ps.Prevotes = BitArray{}
@@ -714,7 +714,7 @@ func (ps *PeerState) ApplyHasVoteMessage(msg *HasVoteMessage) {
 	defer ps.mtx.Unlock()
 
 	// Special case for LastCommits
-	if ps.Height == msg.Height+1 && msg.Type == blk.VoteTypeCommit {
+	if ps.Height == msg.Height+1 && msg.Type == types.VoteTypeCommit {
 		ps.LastCommits.SetIndex(msg.Index, true)
 		return
 	} else if ps.Height != msg.Height {
@@ -784,7 +784,7 @@ func (m *NewRoundStepMessage) String() string {
 
 type CommitStepMessage struct {
 	Height        uint
-	BlockParts    blk.PartSetHeader
+	BlockParts    types.PartSetHeader
 	BlockBitArray BitArray
 }
 
@@ -805,7 +805,7 @@ type PartMessage struct {
 	Height uint
 	Round  uint
 	Type   byte
-	Part   *blk.Part
+	Part   *types.Part
 }
 
 func (m *PartMessage) TypeByte() byte { return msgTypePart }
@@ -818,7 +818,7 @@ func (m *PartMessage) String() string {
 
 type VoteMessage struct {
 	ValidatorIndex uint
-	Vote           *blk.Vote
+	Vote           *types.Vote
 }
 
 func (m *VoteMessage) TypeByte() byte { return msgTypeVote }
diff --git a/consensus/state.go b/consensus/state.go
index 5d5ac8f96..d44dd7b5a 100644
--- a/consensus/state.go
+++ b/consensus/state.go
@@ -62,12 +62,12 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	"github.com/tendermint/tendermint/config"
 	. "github.com/tendermint/tendermint/consensus/types"
 	mempl "github.com/tendermint/tendermint/mempool"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 const (
@@ -171,12 +171,12 @@ type RoundState struct {
 	CommitTime         time.Time // Time when +2/3 commits were found
 	Validators         *sm.ValidatorSet
 	Proposal           *Proposal
-	ProposalBlock      *blk.Block
-	ProposalBlockParts *blk.PartSet
+	ProposalBlock      *types.Block
+	ProposalBlockParts *types.PartSet
 	ProposalPOL        *POL
-	ProposalPOLParts   *blk.PartSet
-	LockedBlock        *blk.Block
-	LockedBlockParts   *blk.PartSet
+	ProposalPOLParts   *types.PartSet
+	LockedBlock        *types.Block
+	LockedBlockParts   *types.PartSet
 	LockedPOL          *POL // Rarely needed, so no LockedPOLParts.
 	Prevotes           *VoteSet
 	Precommits         *VoteSet
@@ -234,20 +234,20 @@ type ConsensusState struct {
 	stopped uint32
 	quit    chan struct{}
 
-	blockStore     *blk.BlockStore
+	blockStore     *types.BlockStore
 	mempoolReactor *mempl.MempoolReactor
 	runActionCh    chan RoundAction
 	newStepCh      chan *RoundState
 
 	mtx sync.Mutex
 	RoundState
-	state                *sm.State  // State until height-1.
-	stagedBlock          *blk.Block // Cache last staged block.
-	stagedState          *sm.State  // Cache result of staged block.
-	lastCommitVoteHeight uint       // Last called commitVoteBlock() or saveCommitVoteBlock() on.
+	state                *sm.State    // State until height-1.
+	stagedBlock          *types.Block // Cache last staged block.
+	stagedState          *sm.State    // Cache result of staged block.
+	lastCommitVoteHeight uint         // Last called commitVoteBlock() or saveCommitVoteBlock() on.
 }
 
-func NewConsensusState(state *sm.State, blockStore *blk.BlockStore, mempoolReactor *mempl.MempoolReactor) *ConsensusState {
+func NewConsensusState(state *sm.State, blockStore *types.BlockStore, mempoolReactor *mempl.MempoolReactor) *ConsensusState {
 	cs := &ConsensusState{
 		quit:           make(chan struct{}),
 		blockStore:     blockStore,
@@ -484,10 +484,10 @@ func (cs *ConsensusState) updateToState(state *sm.State) {
 	cs.LockedBlock = nil
 	cs.LockedBlockParts = nil
 	cs.LockedPOL = nil
-	cs.Prevotes = NewVoteSet(height, 0, blk.VoteTypePrevote, validators)
-	cs.Precommits = NewVoteSet(height, 0, blk.VoteTypePrecommit, validators)
+	cs.Prevotes = NewVoteSet(height, 0, types.VoteTypePrevote, validators)
+	cs.Precommits = NewVoteSet(height, 0, types.VoteTypePrecommit, validators)
 	cs.LastCommits = cs.Commits
-	cs.Commits = NewVoteSet(height, 0, blk.VoteTypeCommit, validators)
+	cs.Commits = NewVoteSet(height, 0, types.VoteTypeCommit, validators)
 
 	cs.state = state
 	cs.stagedBlock = nil
@@ -501,7 +501,7 @@ func (cs *ConsensusState) updateToState(state *sm.State) {
 
 	// If we've timed out, then send rebond tx.
 	if cs.PrivValidator != nil && cs.state.UnbondingValidators.HasAddress(cs.PrivValidator.Address) {
-		rebondTx := &blk.RebondTx{
+		rebondTx := &types.RebondTx{
 			Address: cs.PrivValidator.Address,
 			Height:  cs.Height + 1,
 		}
@@ -534,9 +534,9 @@ func (cs *ConsensusState) setupNewRound(round uint) {
 	cs.ProposalBlockParts = nil
 	cs.ProposalPOL = nil
 	cs.ProposalPOLParts = nil
-	cs.Prevotes = NewVoteSet(cs.Height, round, blk.VoteTypePrevote, validators)
+	cs.Prevotes = NewVoteSet(cs.Height, round, types.VoteTypePrevote, validators)
 	cs.Prevotes.AddFromCommits(cs.Commits)
-	cs.Precommits = NewVoteSet(cs.Height, round, blk.VoteTypePrecommit, validators)
+	cs.Precommits = NewVoteSet(cs.Height, round, types.VoteTypePrecommit, validators)
 	cs.Precommits.AddFromCommits(cs.Commits)
 }
 
@@ -586,10 +586,10 @@ func (cs *ConsensusState) RunActionPropose(height uint, round uint) {
 		log.Debug("Our turn to propose", "proposer", cs.Validators.Proposer().Address, "privValidator", cs.PrivValidator)
 	}
 
-	var block *blk.Block
-	var blockParts *blk.PartSet
+	var block *types.Block
+	var blockParts *types.PartSet
 	var pol *POL
-	var polParts *blk.PartSet
+	var polParts *types.PartSet
 
 	// Decide on block and POL
 	if cs.LockedBlock != nil {
@@ -599,11 +599,11 @@ func (cs *ConsensusState) RunActionPropose(height uint, round uint) {
 		pol = cs.LockedPOL
 	} else {
 		// Otherwise we should create a new proposal.
-		var validation *blk.Validation
+		var validation *types.Validation
 		if cs.Height == 1 {
 			// We're creating a proposal for the first block.
 			// The validation is empty.
-			validation = &blk.Validation{}
+			validation = &types.Validation{}
 		} else if cs.LastCommits.HasTwoThirdsMajority() {
 			// Make the validation from LastCommits
 			validation = cs.LastCommits.MakeValidation()
@@ -617,8 +617,8 @@ func (cs *ConsensusState) RunActionPropose(height uint, round uint) {
 			}
 		}
 		txs := cs.mempoolReactor.Mempool.GetProposalTxs()
-		block = &blk.Block{
-			Header: &blk.Header{
+		block = &types.Block{
+			Header: &types.Header{
 				Network:        config.App().GetString("Network"),
 				Height:         cs.Height,
 				Time:           time.Now(),
@@ -629,24 +629,24 @@ func (cs *ConsensusState) RunActionPropose(height uint, round uint) {
 				StateHash:      nil, // Will set afterwards.
 			},
 			Validation: validation,
-			Data: &blk.Data{
+			Data: &types.Data{
 				Txs: txs,
 			},
 		}
 
-		// Set the blk.Header.StateHash.
+		// Set the types.Header.StateHash.
 		err := cs.state.SetBlockStateHash(block)
 		if err != nil {
 			log.Error("Error setting state hash", "error", err)
 			return
 		}
 
-		blockParts = blk.NewPartSetFromData(binary.BinaryBytes(block))
+		blockParts = types.NewPartSetFromData(binary.BinaryBytes(block))
 		pol = cs.LockedPOL // If exists, is a PoUnlock.
 	}
 
 	if pol != nil {
-		polParts = blk.NewPartSetFromData(binary.BinaryBytes(pol))
+		polParts = types.NewPartSetFromData(binary.BinaryBytes(pol))
 	}
 
 	// Make proposal
@@ -681,14 +681,14 @@ func (cs *ConsensusState) RunActionPrevote(height uint, round uint) {
 
 	// If a block is locked, prevote that.
 	if cs.LockedBlock != nil {
-		cs.signAddVote(blk.VoteTypePrevote, cs.LockedBlock.Hash(), cs.LockedBlockParts.Header())
+		cs.signAddVote(types.VoteTypePrevote, cs.LockedBlock.Hash(), cs.LockedBlockParts.Header())
 		return
 	}
 
 	// If ProposalBlock is nil, prevote nil.
 	if cs.ProposalBlock == nil {
 		log.Warn("ProposalBlock is nil")
-		cs.signAddVote(blk.VoteTypePrevote, nil, blk.PartSetHeader{})
+		cs.signAddVote(types.VoteTypePrevote, nil, types.PartSetHeader{})
 		return
 	}
 
@@ -697,12 +697,12 @@ func (cs *ConsensusState) RunActionPrevote(height uint, round uint) {
 	if err != nil {
 		// ProposalBlock is invalid, prevote nil.
 		log.Warn("ProposalBlock is invalid", "error", err)
-		cs.signAddVote(blk.VoteTypePrevote, nil, blk.PartSetHeader{})
+		cs.signAddVote(types.VoteTypePrevote, nil, types.PartSetHeader{})
 		return
 	}
 
 	// Prevote cs.ProposalBlock
-	cs.signAddVote(blk.VoteTypePrevote, cs.ProposalBlock.Hash(), cs.ProposalBlockParts.Header())
+	cs.signAddVote(types.VoteTypePrevote, cs.ProposalBlock.Hash(), cs.ProposalBlockParts.Header())
 	return
 }
 
@@ -738,7 +738,7 @@ func (cs *ConsensusState) RunActionPrecommit(height uint, round uint) {
 
 	// If +2/3 prevoted for already locked block, precommit it.
 	if cs.LockedBlock.HashesTo(hash) {
-		cs.signAddVote(blk.VoteTypePrecommit, hash, partsHeader)
+		cs.signAddVote(types.VoteTypePrecommit, hash, partsHeader)
 		return
 	}
 
@@ -752,7 +752,7 @@ func (cs *ConsensusState) RunActionPrecommit(height uint, round uint) {
 		}
 		cs.LockedBlock = cs.ProposalBlock
 		cs.LockedBlockParts = cs.ProposalBlockParts
-		cs.signAddVote(blk.VoteTypePrecommit, hash, partsHeader)
+		cs.signAddVote(types.VoteTypePrecommit, hash, partsHeader)
 		return
 	}
 
@@ -806,7 +806,7 @@ func (cs *ConsensusState) RunActionCommit(height uint) {
 			// We're getting the wrong block.
 			// Set up ProposalBlockParts and keep waiting.
 			cs.ProposalBlock = nil
-			cs.ProposalBlockParts = blk.NewPartSetFromHeader(partsHeader)
+			cs.ProposalBlockParts = types.NewPartSetFromHeader(partsHeader)
 
 		} else {
 			// We just need to keep waiting.
@@ -896,14 +896,14 @@ func (cs *ConsensusState) SetProposal(proposal *Proposal) error {
 	}
 
 	cs.Proposal = proposal
-	cs.ProposalBlockParts = blk.NewPartSetFromHeader(proposal.BlockParts)
-	cs.ProposalPOLParts = blk.NewPartSetFromHeader(proposal.POLParts)
+	cs.ProposalBlockParts = types.NewPartSetFromHeader(proposal.BlockParts)
+	cs.ProposalPOLParts = types.NewPartSetFromHeader(proposal.POLParts)
 	return nil
 }
 
 // NOTE: block is not necessarily valid.
 // NOTE: This function may increment the height.
-func (cs *ConsensusState) AddProposalBlockPart(height uint, round uint, part *blk.Part) (added bool, err error) {
+func (cs *ConsensusState) AddProposalBlockPart(height uint, round uint, part *types.Part) (added bool, err error) {
 	cs.mtx.Lock()
 	defer cs.mtx.Unlock()
 
@@ -924,7 +924,7 @@ func (cs *ConsensusState) AddProposalBlockPart(height uint, round uint, part *bl
 	if added && cs.ProposalBlockParts.IsComplete() {
 		var n int64
 		var err error
-		cs.ProposalBlock = binary.ReadBinary(&blk.Block{}, cs.ProposalBlockParts.GetReader(), &n, &err).(*blk.Block)
+		cs.ProposalBlock = binary.ReadBinary(&types.Block{}, cs.ProposalBlockParts.GetReader(), &n, &err).(*types.Block)
 		// If we're already in the commit step, try to finalize round.
 		if cs.Step == RoundStepCommit {
 			cs.queueAction(RoundAction{cs.Height, cs.Round, RoundActionTryFinalize})
@@ -936,7 +936,7 @@ func (cs *ConsensusState) AddProposalBlockPart(height uint, round uint, part *bl
 }
 
 // NOTE: POL is not necessarily valid.
-func (cs *ConsensusState) AddProposalPOLPart(height uint, round uint, part *blk.Part) (added bool, err error) {
+func (cs *ConsensusState) AddProposalPOLPart(height uint, round uint, part *types.Part) (added bool, err error) {
 	cs.mtx.Lock()
 	defer cs.mtx.Unlock()
 
@@ -962,7 +962,7 @@ func (cs *ConsensusState) AddProposalPOLPart(height uint, round uint, part *blk.
 	return true, nil
 }
 
-func (cs *ConsensusState) AddVote(address []byte, vote *blk.Vote) (added bool, index uint, err error) {
+func (cs *ConsensusState) AddVote(address []byte, vote *types.Vote) (added bool, index uint, err error) {
 	cs.mtx.Lock()
 	defer cs.mtx.Unlock()
 
@@ -971,15 +971,15 @@ func (cs *ConsensusState) AddVote(address []byte, vote *blk.Vote) (added bool, i
 
 //-----------------------------------------------------------------------------
 
-func (cs *ConsensusState) addVote(address []byte, vote *blk.Vote) (added bool, index uint, err error) {
+func (cs *ConsensusState) addVote(address []byte, vote *types.Vote) (added bool, index uint, err error) {
 	switch vote.Type {
-	case blk.VoteTypePrevote:
+	case types.VoteTypePrevote:
 		// Prevotes checks for height+round match.
 		return cs.Prevotes.Add(address, vote)
-	case blk.VoteTypePrecommit:
+	case types.VoteTypePrecommit:
 		// Precommits checks for height+round match.
 		return cs.Precommits.Add(address, vote)
-	case blk.VoteTypeCommit:
+	case types.VoteTypeCommit:
 		if vote.Height == cs.Height {
 			// No need to check if vote.Round < cs.Round ...
 			// Prevotes && Precommits already checks that.
@@ -1006,7 +1006,7 @@ func (cs *ConsensusState) addVote(address []byte, vote *blk.Vote) (added bool, i
 	}
 }
 
-func (cs *ConsensusState) stageBlock(block *blk.Block, blockParts *blk.PartSet) error {
+func (cs *ConsensusState) stageBlock(block *types.Block, blockParts *types.PartSet) error {
 	if block == nil {
 		panic("Cannot stage nil block")
 	}
@@ -1031,11 +1031,11 @@ func (cs *ConsensusState) stageBlock(block *blk.Block, blockParts *blk.PartSet)
 	}
 }
 
-func (cs *ConsensusState) signAddVote(type_ byte, hash []byte, header blk.PartSetHeader) *blk.Vote {
+func (cs *ConsensusState) signAddVote(type_ byte, hash []byte, header types.PartSetHeader) *types.Vote {
 	if cs.PrivValidator == nil || !cs.Validators.HasAddress(cs.PrivValidator.Address) {
 		return nil
 	}
-	vote := &blk.Vote{
+	vote := &types.Vote{
 		Height:     cs.Height,
 		Round:      cs.Round,
 		Type:       type_,
@@ -1054,7 +1054,7 @@ func (cs *ConsensusState) signAddVote(type_ byte, hash []byte, header blk.PartSe
 }
 
 // sign a Commit-Vote
-func (cs *ConsensusState) commitVoteBlock(block *blk.Block, blockParts *blk.PartSet) {
+func (cs *ConsensusState) commitVoteBlock(block *types.Block, blockParts *types.PartSet) {
 
 	// The proposal must be valid.
 	if err := cs.stageBlock(block, blockParts); err != nil {
@@ -1065,16 +1065,16 @@ func (cs *ConsensusState) commitVoteBlock(block *blk.Block, blockParts *blk.Part
 
 	// Commit-vote.
 	if cs.lastCommitVoteHeight < block.Height {
-		cs.signAddVote(blk.VoteTypeCommit, block.Hash(), blockParts.Header())
+		cs.signAddVote(types.VoteTypeCommit, block.Hash(), blockParts.Header())
 		cs.lastCommitVoteHeight = block.Height
 	} else {
-		log.Error("Duplicate commitVoteBlock() attempt", "lastCommitVoteHeight", cs.lastCommitVoteHeight, "blk.Height", block.Height)
+		log.Error("Duplicate commitVoteBlock() attempt", "lastCommitVoteHeight", cs.lastCommitVoteHeight, "types.Height", block.Height)
 	}
 }
 
 // Save Block, save the +2/3 Commits we've seen,
 // and sign a Commit-Vote if we haven't already
-func (cs *ConsensusState) saveCommitVoteBlock(block *blk.Block, blockParts *blk.PartSet, commits *VoteSet) {
+func (cs *ConsensusState) saveCommitVoteBlock(block *types.Block, blockParts *types.PartSet, commits *VoteSet) {
 
 	// The proposal must be valid.
 	if err := cs.stageBlock(block, blockParts); err != nil {
@@ -1097,7 +1097,7 @@ func (cs *ConsensusState) saveCommitVoteBlock(block *blk.Block, blockParts *blk.
 
 	// Commit-vote if we haven't already.
 	if cs.lastCommitVoteHeight < block.Height {
-		cs.signAddVote(blk.VoteTypeCommit, block.Hash(), blockParts.Header())
+		cs.signAddVote(types.VoteTypeCommit, block.Hash(), blockParts.Header())
 		cs.lastCommitVoteHeight = block.Height
 	}
 }
diff --git a/consensus/state_test.go b/consensus/state_test.go
index 423f09aa0..60e54a692 100644
--- a/consensus/state_test.go
+++ b/consensus/state_test.go
@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"testing"
 
-	blk "github.com/tendermint/tendermint/block"
+	"github.com/tendermint/tendermint/types"
 )
 
 func TestSetupRound(t *testing.T) {
@@ -12,9 +12,9 @@ func TestSetupRound(t *testing.T) {
 	val0 := privValidators[0]
 
 	// Add a vote, precommit, and commit by val0.
-	voteTypes := []byte{blk.VoteTypePrevote, blk.VoteTypePrecommit, blk.VoteTypeCommit}
+	voteTypes := []byte{types.VoteTypePrevote, types.VoteTypePrecommit, types.VoteTypeCommit}
 	for _, voteType := range voteTypes {
-		vote := &blk.Vote{Height: 1, Round: 0, Type: voteType} // nil vote
+		vote := &types.Vote{Height: 1, Round: 0, Type: voteType} // nil vote
 		err := val0.SignVote(vote)
 		if err != nil {
 			t.Error("Error signing vote: %v", err)
@@ -24,13 +24,13 @@ func TestSetupRound(t *testing.T) {
 
 	// Ensure that vote appears in RoundState.
 	rs0 := cs.GetRoundState()
-	if vote := rs0.Prevotes.GetByAddress(val0.Address); vote == nil || vote.Type != blk.VoteTypePrevote {
+	if vote := rs0.Prevotes.GetByAddress(val0.Address); vote == nil || vote.Type != types.VoteTypePrevote {
 		t.Errorf("Expected to find prevote but got %v", vote)
 	}
-	if vote := rs0.Precommits.GetByAddress(val0.Address); vote == nil || vote.Type != blk.VoteTypePrecommit {
+	if vote := rs0.Precommits.GetByAddress(val0.Address); vote == nil || vote.Type != types.VoteTypePrecommit {
 		t.Errorf("Expected to find precommit but got %v", vote)
 	}
-	if vote := rs0.Commits.GetByAddress(val0.Address); vote == nil || vote.Type != blk.VoteTypeCommit {
+	if vote := rs0.Commits.GetByAddress(val0.Address); vote == nil || vote.Type != types.VoteTypeCommit {
 		t.Errorf("Expected to find commit but got %v", vote)
 	}
 
@@ -40,13 +40,13 @@ func TestSetupRound(t *testing.T) {
 
 	// Now the commit should be copied over to prevotes and precommits.
 	rs1 := cs.GetRoundState()
-	if vote := rs1.Prevotes.GetByAddress(val0.Address); vote == nil || vote.Type != blk.VoteTypeCommit {
+	if vote := rs1.Prevotes.GetByAddress(val0.Address); vote == nil || vote.Type != types.VoteTypeCommit {
 		t.Errorf("Expected to find commit but got %v", vote)
 	}
-	if vote := rs1.Precommits.GetByAddress(val0.Address); vote == nil || vote.Type != blk.VoteTypeCommit {
+	if vote := rs1.Precommits.GetByAddress(val0.Address); vote == nil || vote.Type != types.VoteTypeCommit {
 		t.Errorf("Expected to find commit but got %v", vote)
 	}
-	if vote := rs1.Commits.GetByAddress(val0.Address); vote == nil || vote.Type != blk.VoteTypeCommit {
+	if vote := rs1.Commits.GetByAddress(val0.Address); vote == nil || vote.Type != types.VoteTypeCommit {
 		t.Errorf("Expected to find commit but got %v", vote)
 	}
 
@@ -116,10 +116,10 @@ func TestRunActionPrecommitCommitFinalize(t *testing.T) {
 
 	// Add at least +2/3 prevotes.
 	for i := 0; i < 7; i++ {
-		vote := &blk.Vote{
+		vote := &types.Vote{
 			Height:     1,
 			Round:      0,
-			Type:       blk.VoteTypePrevote,
+			Type:       types.VoteTypePrevote,
 			BlockHash:  cs.ProposalBlock.Hash(),
 			BlockParts: cs.ProposalBlockParts.Header(),
 		}
@@ -146,10 +146,10 @@ func TestRunActionPrecommitCommitFinalize(t *testing.T) {
 			}
 			continue
 		}
-		vote := &blk.Vote{
+		vote := &types.Vote{
 			Height:     1,
 			Round:      0,
-			Type:       blk.VoteTypePrecommit,
+			Type:       types.VoteTypePrecommit,
 			BlockHash:  cs.ProposalBlock.Hash(),
 			BlockParts: cs.ProposalBlockParts.Header(),
 		}
@@ -184,10 +184,10 @@ func TestRunActionPrecommitCommitFinalize(t *testing.T) {
 			}
 			continue
 		}
-		vote := &blk.Vote{
+		vote := &types.Vote{
 			Height:     1,
 			Round:      uint(i), // Doesn't matter what round
-			Type:       blk.VoteTypeCommit,
+			Type:       types.VoteTypeCommit,
 			BlockHash:  cs.ProposalBlock.Hash(),
 			BlockParts: cs.ProposalBlockParts.Header(),
 		}
diff --git a/consensus/test.go b/consensus/test.go
index 2ccdeb3b7..e86c6a075 100644
--- a/consensus/test.go
+++ b/consensus/test.go
@@ -3,15 +3,15 @@ package consensus
 import (
 	"sort"
 
-	blk "github.com/tendermint/tendermint/block"
 	dbm "github.com/tendermint/tendermint/db"
 	mempl "github.com/tendermint/tendermint/mempool"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 func randConsensusState() (*ConsensusState, []*sm.PrivValidator) {
 	state, _, privValidators := sm.RandGenesisState(20, false, 1000, 10, false, 1000)
-	blockStore := blk.NewBlockStore(dbm.NewMemDB())
+	blockStore := types.NewBlockStore(dbm.NewMemDB())
 	mempool := mempl.NewMempool(state)
 	mempoolReactor := mempl.NewMempoolReactor(mempool)
 	cs := NewConsensusState(state, blockStore, mempoolReactor)
diff --git a/consensus/types/proposal.go b/consensus/types/proposal.go
index 22a3963e4..a78570a53 100644
--- a/consensus/types/proposal.go
+++ b/consensus/types/proposal.go
@@ -7,7 +7,7 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
+	"github.com/tendermint/tendermint/types"
 )
 
 var (
@@ -18,12 +18,12 @@ var (
 type Proposal struct {
 	Height     uint
 	Round      uint
-	BlockParts blk.PartSetHeader
-	POLParts   blk.PartSetHeader
+	BlockParts types.PartSetHeader
+	POLParts   types.PartSetHeader
 	Signature  account.SignatureEd25519
 }
 
-func NewProposal(height uint, round uint, blockParts, polParts blk.PartSetHeader) *Proposal {
+func NewProposal(height uint, round uint, blockParts, polParts types.PartSetHeader) *Proposal {
 	return &Proposal{
 		Height:     height,
 		Round:      round,
diff --git a/consensus/vote_set.go b/consensus/vote_set.go
index 627d0e2bb..c640fc51b 100644
--- a/consensus/vote_set.go
+++ b/consensus/vote_set.go
@@ -8,9 +8,9 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 // VoteSet helps collect signatures from validators at each height+round
@@ -25,12 +25,12 @@ type VoteSet struct {
 
 	mtx           sync.Mutex
 	valSet        *sm.ValidatorSet
-	votes         []*blk.Vote       // validator index -> vote
+	votes         []*types.Vote     // validator index -> vote
 	votesBitArray BitArray          // validator index -> has vote?
 	votesByBlock  map[string]uint64 // string(blockHash)+string(blockParts) -> vote sum.
 	totalVotes    uint64
 	maj23Hash     []byte
-	maj23Parts    blk.PartSetHeader
+	maj23Parts    types.PartSetHeader
 	maj23Exists   bool
 }
 
@@ -39,7 +39,7 @@ func NewVoteSet(height uint, round uint, type_ byte, valSet *sm.ValidatorSet) *V
 	if height == 0 {
 		panic("Cannot make VoteSet for height == 0, doesn't make sense.")
 	}
-	if type_ == blk.VoteTypeCommit && round != 0 {
+	if type_ == types.VoteTypeCommit && round != 0 {
 		panic("Expected round 0 for commit vote set")
 	}
 	return &VoteSet{
@@ -47,7 +47,7 @@ func NewVoteSet(height uint, round uint, type_ byte, valSet *sm.ValidatorSet) *V
 		round:         round,
 		type_:         type_,
 		valSet:        valSet,
-		votes:         make([]*blk.Vote, valSet.Size()),
+		votes:         make([]*types.Vote, valSet.Size()),
 		votesBitArray: NewBitArray(valSet.Size()),
 		votesByBlock:  make(map[string]uint64),
 		totalVotes:    0,
@@ -73,40 +73,40 @@ func (voteSet *VoteSet) Size() uint {
 // True if added, false if not.
 // Returns ErrVote[UnexpectedStep|InvalidAccount|InvalidSignature|InvalidBlockHash|ConflictingSignature]
 // NOTE: vote should not be mutated after adding.
-func (voteSet *VoteSet) Add(address []byte, vote *blk.Vote) (bool, uint, error) {
+func (voteSet *VoteSet) Add(address []byte, vote *types.Vote) (bool, uint, error) {
 	voteSet.mtx.Lock()
 	defer voteSet.mtx.Unlock()
 
 	// Make sure the step matches. (or that vote is commit && round < voteSet.round)
 	if vote.Height != voteSet.height ||
-		(vote.Type != blk.VoteTypeCommit && vote.Round != voteSet.round) ||
-		(vote.Type != blk.VoteTypeCommit && vote.Type != voteSet.type_) ||
-		(vote.Type == blk.VoteTypeCommit && voteSet.type_ != blk.VoteTypeCommit && vote.Round >= voteSet.round) {
-		return false, 0, blk.ErrVoteUnexpectedStep
+		(vote.Type != types.VoteTypeCommit && vote.Round != voteSet.round) ||
+		(vote.Type != types.VoteTypeCommit && vote.Type != voteSet.type_) ||
+		(vote.Type == types.VoteTypeCommit && voteSet.type_ != types.VoteTypeCommit && vote.Round >= voteSet.round) {
+		return false, 0, types.ErrVoteUnexpectedStep
 	}
 
 	// Ensure that signer is a validator.
 	valIndex, val := voteSet.valSet.GetByAddress(address)
 	if val == nil {
-		return false, 0, blk.ErrVoteInvalidAccount
+		return false, 0, types.ErrVoteInvalidAccount
 	}
 
 	// Check signature.
 	if !val.PubKey.VerifyBytes(account.SignBytes(vote), vote.Signature) {
 		// Bad signature.
-		return false, 0, blk.ErrVoteInvalidSignature
+		return false, 0, types.ErrVoteInvalidSignature
 	}
 
 	return voteSet.addVote(valIndex, vote)
 }
 
-func (voteSet *VoteSet) addVote(valIndex uint, vote *blk.Vote) (bool, uint, error) {
+func (voteSet *VoteSet) addVote(valIndex uint, vote *types.Vote) (bool, uint, error) {
 	// If vote already exists, return false.
 	if existingVote := voteSet.votes[valIndex]; existingVote != nil {
 		if bytes.Equal(existingVote.BlockHash, vote.BlockHash) {
 			return false, 0, nil
 		} else {
-			return false, 0, &blk.ErrVoteConflictingSignature{
+			return false, 0, &types.ErrVoteConflictingSignature{
 				VoteA: existingVote,
 				VoteB: vote,
 			}
@@ -157,13 +157,13 @@ func (voteSet *VoteSet) BitArray() BitArray {
 	return voteSet.votesBitArray.Copy()
 }
 
-func (voteSet *VoteSet) GetByIndex(valIndex uint) *blk.Vote {
+func (voteSet *VoteSet) GetByIndex(valIndex uint) *types.Vote {
 	voteSet.mtx.Lock()
 	defer voteSet.mtx.Unlock()
 	return voteSet.votes[valIndex]
 }
 
-func (voteSet *VoteSet) GetByAddress(address []byte) *blk.Vote {
+func (voteSet *VoteSet) GetByAddress(address []byte) *types.Vote {
 	voteSet.mtx.Lock()
 	defer voteSet.mtx.Unlock()
 	valIndex, val := voteSet.valSet.GetByAddress(address)
@@ -184,19 +184,19 @@ func (voteSet *VoteSet) HasTwoThirdsMajority() bool {
 
 // Returns either a blockhash (or nil) that received +2/3 majority.
 // If there exists no such majority, returns (nil, false).
-func (voteSet *VoteSet) TwoThirdsMajority() (hash []byte, parts blk.PartSetHeader, ok bool) {
+func (voteSet *VoteSet) TwoThirdsMajority() (hash []byte, parts types.PartSetHeader, ok bool) {
 	voteSet.mtx.Lock()
 	defer voteSet.mtx.Unlock()
 	if voteSet.maj23Exists {
 		return voteSet.maj23Hash, voteSet.maj23Parts, true
 	} else {
-		return nil, blk.PartSetHeader{}, false
+		return nil, types.PartSetHeader{}, false
 	}
 }
 
 func (voteSet *VoteSet) MakePOL() *POL {
-	if voteSet.type_ != blk.VoteTypePrevote {
-		panic("Cannot MakePOL() unless VoteSet.Type is blk.VoteTypePrevote")
+	if voteSet.type_ != types.VoteTypePrevote {
+		panic("Cannot MakePOL() unless VoteSet.Type is types.VoteTypePrevote")
 	}
 	voteSet.mtx.Lock()
 	defer voteSet.mtx.Unlock()
@@ -228,16 +228,16 @@ func (voteSet *VoteSet) MakePOL() *POL {
 	return pol
 }
 
-func (voteSet *VoteSet) MakeValidation() *blk.Validation {
-	if voteSet.type_ != blk.VoteTypeCommit {
-		panic("Cannot MakeValidation() unless VoteSet.Type is blk.VoteTypeCommit")
+func (voteSet *VoteSet) MakeValidation() *types.Validation {
+	if voteSet.type_ != types.VoteTypeCommit {
+		panic("Cannot MakeValidation() unless VoteSet.Type is types.VoteTypeCommit")
 	}
 	voteSet.mtx.Lock()
 	defer voteSet.mtx.Unlock()
 	if len(voteSet.maj23Hash) == 0 {
 		panic("Cannot MakeValidation() unless a blockhash has +2/3")
 	}
-	commits := make([]blk.Commit, voteSet.valSet.Size())
+	commits := make([]types.Commit, voteSet.valSet.Size())
 	voteSet.valSet.Iterate(func(valIndex uint, val *sm.Validator) bool {
 		vote := voteSet.votes[valIndex]
 		if vote == nil {
@@ -249,10 +249,10 @@ func (voteSet *VoteSet) MakeValidation() *blk.Validation {
 		if !vote.BlockParts.Equals(voteSet.maj23Parts) {
 			return false
 		}
-		commits[valIndex] = blk.Commit{val.Address, vote.Round, vote.Signature}
+		commits[valIndex] = types.Commit{val.Address, vote.Round, vote.Signature}
 		return false
 	})
-	return &blk.Validation{
+	return &types.Validation{
 		Commits: commits,
 	}
 }
diff --git a/consensus/vote_set_test.go b/consensus/vote_set_test.go
index db7a271b5..c18892f23 100644
--- a/consensus/vote_set_test.go
+++ b/consensus/vote_set_test.go
@@ -3,10 +3,10 @@ package consensus
 import (
 	"bytes"
 
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	. "github.com/tendermint/tendermint/common/test"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 
 	"testing"
 )
@@ -14,41 +14,41 @@ import (
 // NOTE: see consensus/test.go for common test methods.
 
 // Convenience: Return new vote with different height
-func withHeight(vote *blk.Vote, height uint) *blk.Vote {
+func withHeight(vote *types.Vote, height uint) *types.Vote {
 	vote = vote.Copy()
 	vote.Height = height
 	return vote
 }
 
 // Convenience: Return new vote with different round
-func withRound(vote *blk.Vote, round uint) *blk.Vote {
+func withRound(vote *types.Vote, round uint) *types.Vote {
 	vote = vote.Copy()
 	vote.Round = round
 	return vote
 }
 
 // Convenience: Return new vote with different type
-func withType(vote *blk.Vote, type_ byte) *blk.Vote {
+func withType(vote *types.Vote, type_ byte) *types.Vote {
 	vote = vote.Copy()
 	vote.Type = type_
 	return vote
 }
 
 // Convenience: Return new vote with different blockHash
-func withBlockHash(vote *blk.Vote, blockHash []byte) *blk.Vote {
+func withBlockHash(vote *types.Vote, blockHash []byte) *types.Vote {
 	vote = vote.Copy()
 	vote.BlockHash = blockHash
 	return vote
 }
 
 // Convenience: Return new vote with different blockParts
-func withBlockParts(vote *blk.Vote, blockParts blk.PartSetHeader) *blk.Vote {
+func withBlockParts(vote *types.Vote, blockParts types.PartSetHeader) *types.Vote {
 	vote = vote.Copy()
 	vote.BlockParts = blockParts
 	return vote
 }
 
-func signAddVote(privVal *sm.PrivValidator, vote *blk.Vote, voteSet *VoteSet) (bool, error) {
+func signAddVote(privVal *sm.PrivValidator, vote *types.Vote, voteSet *VoteSet) (bool, error) {
 	privVal.SignVoteUnsafe(vote)
 	added, _, err := voteSet.Add(privVal.Address, vote)
 	return added, err
@@ -56,7 +56,7 @@ func signAddVote(privVal *sm.PrivValidator, vote *blk.Vote, voteSet *VoteSet) (b
 
 func TestAddVote(t *testing.T) {
 	height, round := uint(1), uint(0)
-	voteSet, _, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	voteSet, _, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 	val0 := privValidators[0]
 
 	// t.Logf(">> %v", voteSet)
@@ -72,7 +72,7 @@ func TestAddVote(t *testing.T) {
 		t.Errorf("There should be no 2/3 majority")
 	}
 
-	vote := &blk.Vote{Height: height, Round: round, Type: blk.VoteTypePrevote, BlockHash: nil}
+	vote := &types.Vote{Height: height, Round: round, Type: types.VoteTypePrevote, BlockHash: nil}
 	signAddVote(val0, vote, voteSet)
 
 	if voteSet.GetByAddress(val0.Address) == nil {
@@ -89,9 +89,9 @@ func TestAddVote(t *testing.T) {
 
 func Test2_3Majority(t *testing.T) {
 	height, round := uint(1), uint(0)
-	voteSet, _, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	voteSet, _, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
-	vote := &blk.Vote{Height: height, Round: round, Type: blk.VoteTypePrevote, BlockHash: nil}
+	vote := &types.Vote{Height: height, Round: round, Type: types.VoteTypePrevote, BlockHash: nil}
 
 	// 6 out of 10 voted for nil.
 	for i := 0; i < 6; i++ {
@@ -123,13 +123,13 @@ func Test2_3Majority(t *testing.T) {
 
 func Test2_3MajorityRedux(t *testing.T) {
 	height, round := uint(1), uint(0)
-	voteSet, _, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 100, 1)
+	voteSet, _, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 100, 1)
 
 	blockHash := CRandBytes(32)
 	blockPartsTotal := uint(123)
-	blockParts := blk.PartSetHeader{blockPartsTotal, CRandBytes(32)}
+	blockParts := types.PartSetHeader{blockPartsTotal, CRandBytes(32)}
 
-	vote := &blk.Vote{Height: height, Round: round, Type: blk.VoteTypePrevote, BlockHash: blockHash, BlockParts: blockParts}
+	vote := &types.Vote{Height: height, Round: round, Type: types.VoteTypePrevote, BlockHash: blockHash, BlockParts: blockParts}
 
 	// 66 out of 100 voted for nil.
 	for i := 0; i < 66; i++ {
@@ -151,7 +151,7 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 	// 68th validator voted for a different BlockParts PartSetHeader
 	{
-		blockParts := blk.PartSetHeader{blockPartsTotal, CRandBytes(32)}
+		blockParts := types.PartSetHeader{blockPartsTotal, CRandBytes(32)}
 		signAddVote(privValidators[67], withBlockParts(vote, blockParts), voteSet)
 		hash, header, ok = voteSet.TwoThirdsMajority()
 		if hash != nil || !header.IsZero() || ok {
@@ -161,7 +161,7 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 	// 69th validator voted for different BlockParts Total
 	{
-		blockParts := blk.PartSetHeader{blockPartsTotal + 1, blockParts.Hash}
+		blockParts := types.PartSetHeader{blockPartsTotal + 1, blockParts.Hash}
 		signAddVote(privValidators[68], withBlockParts(vote, blockParts), voteSet)
 		hash, header, ok = voteSet.TwoThirdsMajority()
 		if hash != nil || !header.IsZero() || ok {
@@ -190,10 +190,10 @@ func Test2_3MajorityRedux(t *testing.T) {
 
 func TestBadVotes(t *testing.T) {
 	height, round := uint(1), uint(0)
-	voteSet, _, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	voteSet, _, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// val0 votes for nil.
-	vote := &blk.Vote{Height: height, Round: round, Type: blk.VoteTypePrevote, BlockHash: nil}
+	vote := &types.Vote{Height: height, Round: round, Type: types.VoteTypePrevote, BlockHash: nil}
 	added, err := signAddVote(privValidators[0], vote, voteSet)
 	if !added || err != nil {
 		t.Errorf("Expected Add() to succeed")
@@ -218,7 +218,7 @@ func TestBadVotes(t *testing.T) {
 	}
 
 	// val3 votes of another type.
-	added, err = signAddVote(privValidators[3], withType(vote, blk.VoteTypePrecommit), voteSet)
+	added, err = signAddVote(privValidators[3], withType(vote, types.VoteTypePrecommit), voteSet)
 	if added {
 		t.Errorf("Expected Add() to fail, wrong type")
 	}
@@ -226,10 +226,10 @@ func TestBadVotes(t *testing.T) {
 
 func TestAddCommitsToPrevoteVotes(t *testing.T) {
 	height, round := uint(2), uint(5)
-	voteSet, _, privValidators := randVoteSet(height, round, blk.VoteTypePrevote, 10, 1)
+	voteSet, _, privValidators := randVoteSet(height, round, types.VoteTypePrevote, 10, 1)
 
 	// val0, val1, val2, val3, val4, val5 vote for nil.
-	vote := &blk.Vote{Height: height, Round: round, Type: blk.VoteTypePrevote, BlockHash: nil}
+	vote := &types.Vote{Height: height, Round: round, Type: types.VoteTypePrevote, BlockHash: nil}
 	for i := 0; i < 6; i++ {
 		signAddVote(privValidators[i], vote, voteSet)
 	}
@@ -239,35 +239,35 @@ func TestAddCommitsToPrevoteVotes(t *testing.T) {
 	}
 
 	// Attempt to add a commit from val6 at a previous height
-	vote = &blk.Vote{Height: height - 1, Round: round, Type: blk.VoteTypeCommit, BlockHash: nil}
+	vote = &types.Vote{Height: height - 1, Round: round, Type: types.VoteTypeCommit, BlockHash: nil}
 	added, _ := signAddVote(privValidators[6], vote, voteSet)
 	if added {
 		t.Errorf("Expected Add() to fail, wrong height.")
 	}
 
 	// Attempt to add a commit from val6 at a later round
-	vote = &blk.Vote{Height: height, Round: round + 1, Type: blk.VoteTypeCommit, BlockHash: nil}
+	vote = &types.Vote{Height: height, Round: round + 1, Type: types.VoteTypeCommit, BlockHash: nil}
 	added, _ = signAddVote(privValidators[6], vote, voteSet)
 	if added {
 		t.Errorf("Expected Add() to fail, cannot add future round vote.")
 	}
 
 	// Attempt to add a commit from val6 for currrent height/round.
-	vote = &blk.Vote{Height: height, Round: round, Type: blk.VoteTypeCommit, BlockHash: nil}
+	vote = &types.Vote{Height: height, Round: round, Type: types.VoteTypeCommit, BlockHash: nil}
 	added, err := signAddVote(privValidators[6], vote, voteSet)
 	if added || err == nil {
 		t.Errorf("Expected Add() to fail, only prior round commits can be added.")
 	}
 
 	// Add commit from val6 at a previous round
-	vote = &blk.Vote{Height: height, Round: round - 1, Type: blk.VoteTypeCommit, BlockHash: nil}
+	vote = &types.Vote{Height: height, Round: round - 1, Type: types.VoteTypeCommit, BlockHash: nil}
 	added, err = signAddVote(privValidators[6], vote, voteSet)
 	if !added || err != nil {
 		t.Errorf("Expected Add() to succeed, commit for prior rounds are relevant.")
 	}
 
 	// Also add commit from val7 for previous round.
-	vote = &blk.Vote{Height: height, Round: round - 2, Type: blk.VoteTypeCommit, BlockHash: nil}
+	vote = &types.Vote{Height: height, Round: round - 2, Type: types.VoteTypeCommit, BlockHash: nil}
 	added, err = signAddVote(privValidators[7], vote, voteSet)
 	if !added || err != nil {
 		t.Errorf("Expected Add() to succeed. err: %v", err)
@@ -283,10 +283,10 @@ func TestAddCommitsToPrevoteVotes(t *testing.T) {
 
 func TestMakeValidation(t *testing.T) {
 	height, round := uint(1), uint(0)
-	voteSet, _, privValidators := randVoteSet(height, round, blk.VoteTypeCommit, 10, 1)
-	blockHash, blockParts := CRandBytes(32), blk.PartSetHeader{123, CRandBytes(32)}
+	voteSet, _, privValidators := randVoteSet(height, round, types.VoteTypeCommit, 10, 1)
+	blockHash, blockParts := CRandBytes(32), types.PartSetHeader{123, CRandBytes(32)}
 
-	vote := &blk.Vote{Height: height, Round: round, Type: blk.VoteTypeCommit,
+	vote := &types.Vote{Height: height, Round: round, Type: types.VoteTypeCommit,
 		BlockHash: blockHash, BlockParts: blockParts}
 
 	// 6 out of 10 voted for some block.
@@ -300,7 +300,7 @@ func TestMakeValidation(t *testing.T) {
 	// 7th voted for some other block.
 	{
 		vote := withBlockHash(vote, RandBytes(32))
-		vote = withBlockParts(vote, blk.PartSetHeader{123, RandBytes(32)})
+		vote = withBlockParts(vote, types.PartSetHeader{123, RandBytes(32)})
 		signAddVote(privValidators[6], vote, voteSet)
 	}
 
diff --git a/daemon/daemon.go b/daemon/daemon.go
index 72a615c20..ccb2932de 100644
--- a/daemon/daemon.go
+++ b/daemon/daemon.go
@@ -4,7 +4,6 @@ import (
 	"os"
 	"os/signal"
 
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	"github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/consensus"
@@ -13,6 +12,7 @@ import (
 	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/rpc"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 type Node struct {
@@ -20,7 +20,7 @@ type Node struct {
 	sw               *p2p.Switch
 	book             *p2p.AddrBook
 	pexReactor       *p2p.PEXReactor
-	blockStore       *blk.BlockStore
+	blockStore       *types.BlockStore
 	mempoolReactor   *mempl.MempoolReactor
 	consensusState   *consensus.ConsensusState
 	consensusReactor *consensus.ConsensusReactor
@@ -30,7 +30,7 @@ type Node struct {
 func NewNode() *Node {
 	// Get BlockStore
 	blockStoreDB := dbm.GetDB("blockstore")
-	blockStore := blk.NewBlockStore(blockStoreDB)
+	blockStore := types.NewBlockStore(blockStoreDB)
 
 	// Get State
 	stateDB := dbm.GetDB("state")
diff --git a/mempool/mempool.go b/mempool/mempool.go
index 4743e6380..e955dfacf 100644
--- a/mempool/mempool.go
+++ b/mempool/mempool.go
@@ -12,14 +12,14 @@ import (
 	"sync"
 
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	sm "github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 type Mempool struct {
 	mtx   sync.Mutex
 	state *sm.State
-	txs   []blk.Tx
+	txs   []types.Tx
 }
 
 func NewMempool(state *sm.State) *Mempool {
@@ -33,7 +33,7 @@ func (mem *Mempool) GetState() *sm.State {
 }
 
 // Apply tx to the state and remember it.
-func (mem *Mempool) AddTx(tx blk.Tx) (err error) {
+func (mem *Mempool) AddTx(tx types.Tx) (err error) {
 	mem.mtx.Lock()
 	defer mem.mtx.Unlock()
 	err = mem.state.ExecTx(tx, false)
@@ -47,7 +47,7 @@ func (mem *Mempool) AddTx(tx blk.Tx) (err error) {
 	}
 }
 
-func (mem *Mempool) GetProposalTxs() []blk.Tx {
+func (mem *Mempool) GetProposalTxs() []types.Tx {
 	mem.mtx.Lock()
 	defer mem.mtx.Unlock()
 	log.Debug("GetProposalTxs:", "txs", mem.txs)
@@ -58,7 +58,7 @@ func (mem *Mempool) GetProposalTxs() []blk.Tx {
 // "state" is the result of state.AppendBlock("block").
 // Txs that are present in "block" are discarded from mempool.
 // Txs that have become invalid in the new "state" are also discarded.
-func (mem *Mempool) ResetForBlockAndState(block *blk.Block, state *sm.State) {
+func (mem *Mempool) ResetForBlockAndState(block *types.Block, state *sm.State) {
 	mem.mtx.Lock()
 	defer mem.mtx.Unlock()
 	mem.state = state.Copy()
@@ -71,7 +71,7 @@ func (mem *Mempool) ResetForBlockAndState(block *blk.Block, state *sm.State) {
 	}
 
 	// Next, filter all txs from mem.txs that are in blockTxsMap
-	txs := []blk.Tx{}
+	txs := []types.Tx{}
 	for _, tx := range mem.txs {
 		txHash := binary.BinarySha256(tx)
 		if _, ok := blockTxsMap[string(txHash)]; ok {
@@ -84,7 +84,7 @@ func (mem *Mempool) ResetForBlockAndState(block *blk.Block, state *sm.State) {
 	}
 
 	// Next, filter all txs that aren't valid given new state.
-	validTxs := []blk.Tx{}
+	validTxs := []types.Tx{}
 	for _, tx := range txs {
 		err := mem.state.ExecTx(tx, false)
 		if err == nil {
diff --git a/mempool/reactor.go b/mempool/reactor.go
index 7381d1ad2..5bed4e18b 100644
--- a/mempool/reactor.go
+++ b/mempool/reactor.go
@@ -6,8 +6,8 @@ import (
 	"sync/atomic"
 
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	"github.com/tendermint/tendermint/p2p"
+	"github.com/tendermint/tendermint/types"
 )
 
 var (
@@ -100,7 +100,7 @@ func (memR *MempoolReactor) Receive(chId byte, src *p2p.Peer, msgBytes []byte) {
 	}
 }
 
-func (memR *MempoolReactor) BroadcastTx(tx blk.Tx) error {
+func (memR *MempoolReactor) BroadcastTx(tx types.Tx) error {
 	err := memR.Mempool.AddTx(tx)
 	if err != nil {
 		return err
@@ -135,7 +135,7 @@ func DecodeMessage(bz []byte) (msgType byte, msg interface{}, err error) {
 //-------------------------------------
 
 type TxMessage struct {
-	Tx blk.Tx
+	Tx types.Tx
 }
 
 func (m *TxMessage) TypeByte() byte { return msgTypeTx }
diff --git a/rpc/blocks.go b/rpc/blocks.go
index 2703767f1..1415f1ff0 100644
--- a/rpc/blocks.go
+++ b/rpc/blocks.go
@@ -3,8 +3,8 @@ package rpc
 import (
 	"net/http"
 
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
+	"github.com/tendermint/tendermint/types"
 )
 
 func BlockchainInfoHandler(w http.ResponseWriter, r *http.Request) {
@@ -20,7 +20,7 @@ func BlockchainInfoHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	log.Debug("BlockchainInfoHandler", "maxHeight", maxHeight, "minHeight", minHeight)
 
-	blockMetas := []*blk.BlockMeta{}
+	blockMetas := []*types.BlockMeta{}
 	for height := maxHeight; height >= minHeight; height-- {
 		blockMeta := blockStore.LoadBlockMeta(height)
 		blockMetas = append(blockMetas, blockMeta)
@@ -28,7 +28,7 @@ func BlockchainInfoHandler(w http.ResponseWriter, r *http.Request) {
 
 	WriteAPIResponse(w, API_OK, struct {
 		LastHeight uint
-		BlockMetas []*blk.BlockMeta
+		BlockMetas []*types.BlockMeta
 	}{blockStore.Height(), blockMetas})
 }
 
@@ -49,7 +49,7 @@ func GetBlockHandler(w http.ResponseWriter, r *http.Request) {
 	block := blockStore.LoadBlock(height)
 
 	WriteAPIResponse(w, API_OK, struct {
-		BlockMeta *blk.BlockMeta
-		Block     *blk.Block
+		BlockMeta *types.BlockMeta
+		Block     *types.Block
 	}{blockMeta, block})
 }
diff --git a/rpc/mempool.go b/rpc/mempool.go
index 0296ee69d..81402ebb3 100644
--- a/rpc/mempool.go
+++ b/rpc/mempool.go
@@ -4,16 +4,16 @@ import (
 	"net/http"
 
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	"github.com/tendermint/tendermint/merkle"
 	"github.com/tendermint/tendermint/state"
+	"github.com/tendermint/tendermint/types"
 )
 
 func BroadcastTxHandler(w http.ResponseWriter, r *http.Request) {
 	txJSON := GetParam(r, "tx")
 	var err error
-	var tx blk.Tx
+	var tx types.Tx
 	binary.ReadJSON(&tx, []byte(txJSON), &err)
 	if err != nil {
 		WriteAPIResponse(w, API_INVALID_PARAM, Fmt("Invalid tx: %v", err))
@@ -30,7 +30,7 @@ func BroadcastTxHandler(w http.ResponseWriter, r *http.Request) {
 	var createsContract bool
 	var contractAddr []byte
 
-	if callTx, ok := tx.(*blk.CallTx); ok {
+	if callTx, ok := tx.(*types.CallTx); ok {
 		if callTx.Address == nil {
 			createsContract = true
 			contractAddr = state.NewContractAddress(callTx.Input.Address, uint64(callTx.Input.Sequence))
diff --git a/rpc/rpc.go b/rpc/rpc.go
index 7d4526b8b..94631249c 100644
--- a/rpc/rpc.go
+++ b/rpc/rpc.go
@@ -1,18 +1,18 @@
 package rpc
 
 import (
-	blk "github.com/tendermint/tendermint/block"
 	"github.com/tendermint/tendermint/consensus"
 	mempl "github.com/tendermint/tendermint/mempool"
 	"github.com/tendermint/tendermint/p2p"
+	"github.com/tendermint/tendermint/types"
 )
 
-var blockStore *blk.BlockStore
+var blockStore *types.BlockStore
 var consensusState *consensus.ConsensusState
 var mempoolReactor *mempl.MempoolReactor
 var p2pSwitch *p2p.Switch
 
-func SetRPCBlockStore(bs *blk.BlockStore) {
+func SetRPCBlockStore(bs *types.BlockStore) {
 	blockStore = bs
 }
 
diff --git a/rpc/txs.go b/rpc/txs.go
index 92fdea9d0..5c7588f77 100644
--- a/rpc/txs.go
+++ b/rpc/txs.go
@@ -5,8 +5,8 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
+	"github.com/tendermint/tendermint/types"
 )
 
 func SignTxHandler(w http.ResponseWriter, r *http.Request) {
@@ -14,7 +14,7 @@ func SignTxHandler(w http.ResponseWriter, r *http.Request) {
 	privAccountsStr := GetParam(r, "privAccounts")
 
 	var err error
-	var tx blk.Tx
+	var tx types.Tx
 	binary.ReadJSON(&tx, []byte(txStr), &err)
 	if err != nil {
 		WriteAPIResponse(w, API_INVALID_PARAM, Fmt("Invalid tx: %v", err))
@@ -33,25 +33,25 @@ func SignTxHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	switch tx.(type) {
-	case *blk.SendTx:
-		sendTx := tx.(*blk.SendTx)
+	case *types.SendTx:
+		sendTx := tx.(*types.SendTx)
 		for i, input := range sendTx.Inputs {
 			input.PubKey = privAccounts[i].PubKey
 			input.Signature = privAccounts[i].Sign(sendTx)
 		}
-	case *blk.BondTx:
-		bondTx := tx.(*blk.BondTx)
+	case *types.BondTx:
+		bondTx := tx.(*types.BondTx)
 		for i, input := range bondTx.Inputs {
 			input.PubKey = privAccounts[i].PubKey
 			input.Signature = privAccounts[i].Sign(bondTx)
 		}
-	case *blk.UnbondTx:
-		unbondTx := tx.(*blk.UnbondTx)
+	case *types.UnbondTx:
+		unbondTx := tx.(*types.UnbondTx)
 		unbondTx.Signature = privAccounts[0].Sign(unbondTx).(account.SignatureEd25519)
-	case *blk.RebondTx:
-		rebondTx := tx.(*blk.RebondTx)
+	case *types.RebondTx:
+		rebondTx := tx.(*types.RebondTx)
 		rebondTx.Signature = privAccounts[0].Sign(rebondTx).(account.SignatureEd25519)
 	}
 
-	WriteAPIResponse(w, API_OK, struct{ blk.Tx }{tx})
+	WriteAPIResponse(w, API_OK, struct{ types.Tx }{tx})
 }
diff --git a/state/genesis.go b/state/genesis.go
index d5590c408..9b75db976 100644
--- a/state/genesis.go
+++ b/state/genesis.go
@@ -6,10 +6,10 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	dbm "github.com/tendermint/tendermint/db"
 	"github.com/tendermint/tendermint/merkle"
+	"github.com/tendermint/tendermint/types"
 )
 
 type GenesisAccount struct {
@@ -79,12 +79,12 @@ func MakeGenesisState(db dbm.DB, genDoc *GenesisDoc) *State {
 		valInfo := &ValidatorInfo{
 			Address:         address,
 			PubKey:          pubKey,
-			UnbondTo:        make([]*blk.TxOutput, len(val.UnbondTo)),
+			UnbondTo:        make([]*types.TxOutput, len(val.UnbondTo)),
 			FirstBondHeight: 0,
 			FirstBondAmount: val.Amount,
 		}
 		for i, unbondTo := range val.UnbondTo {
-			valInfo.UnbondTo[i] = &blk.TxOutput{
+			valInfo.UnbondTo[i] = &types.TxOutput{
 				Address: unbondTo.Address,
 				Amount:  unbondTo.Amount,
 			}
@@ -107,7 +107,7 @@ func MakeGenesisState(db dbm.DB, genDoc *GenesisDoc) *State {
 		DB:                   db,
 		LastBlockHeight:      0,
 		LastBlockHash:        nil,
-		LastBlockParts:       blk.PartSetHeader{},
+		LastBlockParts:       types.PartSetHeader{},
 		LastBlockTime:        genDoc.GenesisTime,
 		BondedValidators:     NewValidatorSet(validators),
 		LastBondedValidators: NewValidatorSet(nil),
diff --git a/state/priv_validator.go b/state/priv_validator.go
index 854df45a7..733d1151c 100644
--- a/state/priv_validator.go
+++ b/state/priv_validator.go
@@ -11,10 +11,10 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	"github.com/tendermint/tendermint/config"
 	. "github.com/tendermint/tendermint/consensus/types"
+	"github.com/tendermint/tendermint/types"
 
 	"github.com/tendermint/ed25519"
 )
@@ -27,13 +27,13 @@ const (
 	stepCommit    = 4
 )
 
-func voteToStep(vote *blk.Vote) uint8 {
+func voteToStep(vote *types.Vote) uint8 {
 	switch vote.Type {
-	case blk.VoteTypePrevote:
+	case types.VoteTypePrevote:
 		return stepPrevote
-	case blk.VoteTypePrecommit:
+	case types.VoteTypePrecommit:
 		return stepPrecommit
-	case blk.VoteTypeCommit:
+	case types.VoteTypeCommit:
 		return stepCommit
 	default:
 		panic("Unknown vote type")
@@ -100,7 +100,7 @@ func (privVal *PrivValidator) save() {
 }
 
 // TODO: test
-func (privVal *PrivValidator) SignVote(vote *blk.Vote) error {
+func (privVal *PrivValidator) SignVote(vote *types.Vote) error {
 	privVal.mtx.Lock()
 	defer privVal.mtx.Unlock()
 
@@ -135,7 +135,7 @@ func (privVal *PrivValidator) SignVote(vote *blk.Vote) error {
 	return nil
 }
 
-func (privVal *PrivValidator) SignVoteUnsafe(vote *blk.Vote) {
+func (privVal *PrivValidator) SignVoteUnsafe(vote *types.Vote) {
 	vote.Signature = privVal.PrivKey.Sign(account.SignBytes(vote)).(account.SignatureEd25519)
 }
 
@@ -160,7 +160,7 @@ func (privVal *PrivValidator) SignProposal(proposal *Proposal) error {
 	}
 }
 
-func (privVal *PrivValidator) SignRebondTx(rebondTx *blk.RebondTx) error {
+func (privVal *PrivValidator) SignRebondTx(rebondTx *types.RebondTx) error {
 	privVal.mtx.Lock()
 	defer privVal.mtx.Unlock()
 	if privVal.LastHeight < rebondTx.Height {
diff --git a/state/state.go b/state/state.go
index e4e21cbbf..a3f3586eb 100644
--- a/state/state.go
+++ b/state/state.go
@@ -8,10 +8,10 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	dbm "github.com/tendermint/tendermint/db"
 	"github.com/tendermint/tendermint/merkle"
+	"github.com/tendermint/tendermint/types"
 	"github.com/tendermint/tendermint/vm"
 )
 
@@ -26,7 +26,7 @@ var (
 //-----------------------------------------------------------------------------
 
 type InvalidTxError struct {
-	Tx     blk.Tx
+	Tx     types.Tx
 	Reason error
 }
 
@@ -41,7 +41,7 @@ type State struct {
 	DB                   dbm.DB
 	LastBlockHeight      uint
 	LastBlockHash        []byte
-	LastBlockParts       blk.PartSetHeader
+	LastBlockParts       types.PartSetHeader
 	LastBlockTime        time.Time
 	BondedValidators     *ValidatorSet
 	LastBondedValidators *ValidatorSet
@@ -59,7 +59,7 @@ func LoadState(db dbm.DB) *State {
 		r, n, err := bytes.NewReader(buf), new(int64), new(error)
 		s.LastBlockHeight = binary.ReadUvarint(r, n, err)
 		s.LastBlockHash = binary.ReadByteSlice(r, n, err)
-		s.LastBlockParts = binary.ReadBinary(blk.PartSetHeader{}, r, n, err).(blk.PartSetHeader)
+		s.LastBlockParts = binary.ReadBinary(types.PartSetHeader{}, r, n, err).(types.PartSetHeader)
 		s.LastBlockTime = binary.ReadTime(r, n, err)
 		s.BondedValidators = binary.ReadBinary(&ValidatorSet{}, r, n, err).(*ValidatorSet)
 		s.LastBondedValidators = binary.ReadBinary(&ValidatorSet{}, r, n, err).(*ValidatorSet)
@@ -117,16 +117,16 @@ func (s *State) Copy() *State {
 // account.PubKey.(type) != PubKeyNil, (it must be known),
 // or it must be specified in the TxInput.  If redeclared,
 // the TxInput is modified and input.PubKey set to PubKeyNil.
-func (s *State) GetOrMakeAccounts(ins []*blk.TxInput, outs []*blk.TxOutput) (map[string]*account.Account, error) {
+func (s *State) GetOrMakeAccounts(ins []*types.TxInput, outs []*types.TxOutput) (map[string]*account.Account, error) {
 	accounts := map[string]*account.Account{}
 	for _, in := range ins {
 		// Account shouldn't be duplicated
 		if _, ok := accounts[string(in.Address)]; ok {
-			return nil, blk.ErrTxDuplicateAddress
+			return nil, types.ErrTxDuplicateAddress
 		}
 		acc := s.GetAccount(in.Address)
 		if acc == nil {
-			return nil, blk.ErrTxInvalidAddress
+			return nil, types.ErrTxInvalidAddress
 		}
 		// PubKey should be present in either "account" or "in"
 		if err := checkInputPubKey(acc, in); err != nil {
@@ -137,7 +137,7 @@ func (s *State) GetOrMakeAccounts(ins []*blk.TxInput, outs []*blk.TxOutput) (map
 	for _, out := range outs {
 		// Account shouldn't be duplicated
 		if _, ok := accounts[string(out.Address)]; ok {
-			return nil, blk.ErrTxDuplicateAddress
+			return nil, types.ErrTxDuplicateAddress
 		}
 		acc := s.GetAccount(out.Address)
 		// output account may be nil (new)
@@ -154,13 +154,13 @@ func (s *State) GetOrMakeAccounts(ins []*blk.TxInput, outs []*blk.TxOutput) (map
 	return accounts, nil
 }
 
-func checkInputPubKey(acc *account.Account, in *blk.TxInput) error {
+func checkInputPubKey(acc *account.Account, in *types.TxInput) error {
 	if _, isNil := acc.PubKey.(account.PubKeyNil); isNil {
 		if _, isNil := in.PubKey.(account.PubKeyNil); isNil {
-			return blk.ErrTxUnknownPubKey
+			return types.ErrTxUnknownPubKey
 		}
 		if !bytes.Equal(in.PubKey.Address(), acc.Address) {
-			return blk.ErrTxInvalidPubKey
+			return types.ErrTxInvalidPubKey
 		}
 		acc.PubKey = in.PubKey
 	} else {
@@ -169,7 +169,7 @@ func checkInputPubKey(acc *account.Account, in *blk.TxInput) error {
 	return nil
 }
 
-func (s *State) ValidateInputs(accounts map[string]*account.Account, signBytes []byte, ins []*blk.TxInput) (total uint64, err error) {
+func (s *State) ValidateInputs(accounts map[string]*account.Account, signBytes []byte, ins []*types.TxInput) (total uint64, err error) {
 	for _, in := range ins {
 		acc := accounts[string(in.Address)]
 		if acc == nil {
@@ -185,30 +185,30 @@ func (s *State) ValidateInputs(accounts map[string]*account.Account, signBytes [
 	return total, nil
 }
 
-func (s *State) ValidateInput(acc *account.Account, signBytes []byte, in *blk.TxInput) (err error) {
+func (s *State) ValidateInput(acc *account.Account, signBytes []byte, in *types.TxInput) (err error) {
 	// Check TxInput basic
 	if err := in.ValidateBasic(); err != nil {
 		return err
 	}
 	// Check signatures
 	if !acc.PubKey.VerifyBytes(signBytes, in.Signature) {
-		return blk.ErrTxInvalidSignature
+		return types.ErrTxInvalidSignature
 	}
 	// Check sequences
 	if acc.Sequence+1 != in.Sequence {
-		return blk.ErrTxInvalidSequence{
+		return types.ErrTxInvalidSequence{
 			Got:      uint64(in.Sequence),
 			Expected: uint64(acc.Sequence + 1),
 		}
 	}
 	// Check amount
 	if acc.Balance < in.Amount {
-		return blk.ErrTxInsufficientFunds
+		return types.ErrTxInsufficientFunds
 	}
 	return nil
 }
 
-func (s *State) ValidateOutputs(outs []*blk.TxOutput) (total uint64, err error) {
+func (s *State) ValidateOutputs(outs []*types.TxOutput) (total uint64, err error) {
 	for _, out := range outs {
 		// Check TxOutput basic
 		if err := out.ValidateBasic(); err != nil {
@@ -220,7 +220,7 @@ func (s *State) ValidateOutputs(outs []*blk.TxOutput) (total uint64, err error)
 	return total, nil
 }
 
-func (s *State) AdjustByInputs(accounts map[string]*account.Account, ins []*blk.TxInput) {
+func (s *State) AdjustByInputs(accounts map[string]*account.Account, ins []*types.TxInput) {
 	for _, in := range ins {
 		acc := accounts[string(in.Address)]
 		if acc == nil {
@@ -234,7 +234,7 @@ func (s *State) AdjustByInputs(accounts map[string]*account.Account, ins []*blk.
 	}
 }
 
-func (s *State) AdjustByOutputs(accounts map[string]*account.Account, outs []*blk.TxOutput) {
+func (s *State) AdjustByOutputs(accounts map[string]*account.Account, outs []*types.TxOutput) {
 	for _, out := range outs {
 		acc := accounts[string(out.Address)]
 		if acc == nil {
@@ -246,14 +246,14 @@ func (s *State) AdjustByOutputs(accounts map[string]*account.Account, outs []*bl
 
 // If the tx is invalid, an error will be returned.
 // Unlike AppendBlock(), state will not be altered.
-func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
+func (s *State) ExecTx(tx_ types.Tx, runCall bool) error {
 
 	// TODO: do something with fees
 	fees := uint64(0)
 
 	// Exec tx
 	switch tx := tx_.(type) {
-	case *blk.SendTx:
+	case *types.SendTx:
 		accounts, err := s.GetOrMakeAccounts(tx.Inputs, tx.Outputs)
 		if err != nil {
 			return err
@@ -268,7 +268,7 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 			return err
 		}
 		if outTotal > inTotal {
-			return blk.ErrTxInsufficientFunds
+			return types.ErrTxInsufficientFunds
 		}
 		fee := inTotal - outTotal
 		fees += fee
@@ -279,14 +279,14 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 		s.UpdateAccounts(accounts)
 		return nil
 
-	case *blk.CallTx:
+	case *types.CallTx:
 		var inAcc, outAcc *account.Account
 
 		// Validate input
 		inAcc = s.GetAccount(tx.Input.Address)
 		if inAcc == nil {
 			log.Debug(Fmt("Can't find in account %X", tx.Input.Address))
-			return blk.ErrTxInvalidAddress
+			return types.ErrTxInvalidAddress
 		}
 		// pubKey should be present in either "inAcc" or "tx.Input"
 		if err := checkInputPubKey(inAcc, tx.Input); err != nil {
@@ -301,7 +301,7 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 		}
 		if tx.Input.Amount < tx.Fee {
 			log.Debug(Fmt("Sender did not send enough to cover the fee %X", tx.Input.Address))
-			return blk.ErrTxInsufficientFunds
+			return types.ErrTxInsufficientFunds
 		}
 
 		createAccount := len(tx.Address) == 0
@@ -309,7 +309,7 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 			// Validate output
 			if len(tx.Address) != 20 {
 				log.Debug(Fmt("Destination address is not 20 bytes %X", tx.Address))
-				return blk.ErrTxInvalidAddress
+				return types.ErrTxInvalidAddress
 			}
 			// this may be nil if we are still in mempool and contract was created in same block as this tx
 			// but that's fine, because the account will be created properly when the create tx runs in the block
@@ -348,7 +348,7 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 					inAcc.Balance -= tx.Fee
 					s.UpdateAccount(inAcc)
 					log.Debug(Fmt("Cannot find destination address %X. Deducting fee from caller", tx.Address))
-					return blk.ErrTxInvalidAddress
+					return types.ErrTxInvalidAddress
 
 				}
 				callee = toVMAccount(outAcc)
@@ -401,7 +401,7 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 
 		return nil
 
-	case *blk.BondTx:
+	case *types.BondTx:
 		valInfo := s.GetValidatorInfo(tx.PubKey.Address())
 		if valInfo != nil {
 			// TODO: In the future, check that the validator wasn't destroyed,
@@ -425,7 +425,7 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 			return err
 		}
 		if outTotal > inTotal {
-			return blk.ErrTxInsufficientFunds
+			return types.ErrTxInsufficientFunds
 		}
 		fee := inTotal - outTotal
 		fees += fee
@@ -454,17 +454,17 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 		}
 		return nil
 
-	case *blk.UnbondTx:
+	case *types.UnbondTx:
 		// The validator must be active
 		_, val := s.BondedValidators.GetByAddress(tx.Address)
 		if val == nil {
-			return blk.ErrTxInvalidAddress
+			return types.ErrTxInvalidAddress
 		}
 
 		// Verify the signature
 		signBytes := account.SignBytes(tx)
 		if !val.PubKey.VerifyBytes(signBytes, tx.Signature) {
-			return blk.ErrTxInvalidSignature
+			return types.ErrTxInvalidSignature
 		}
 
 		// tx.Height must be greater than val.LastCommitHeight
@@ -476,17 +476,17 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 		s.unbondValidator(val)
 		return nil
 
-	case *blk.RebondTx:
+	case *types.RebondTx:
 		// The validator must be inactive
 		_, val := s.UnbondingValidators.GetByAddress(tx.Address)
 		if val == nil {
-			return blk.ErrTxInvalidAddress
+			return types.ErrTxInvalidAddress
 		}
 
 		// Verify the signature
 		signBytes := account.SignBytes(tx)
 		if !val.PubKey.VerifyBytes(signBytes, tx.Signature) {
-			return blk.ErrTxInvalidSignature
+			return types.ErrTxInvalidSignature
 		}
 
 		// tx.Height must be equal to the next height
@@ -498,20 +498,20 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 		s.rebondValidator(val)
 		return nil
 
-	case *blk.DupeoutTx:
+	case *types.DupeoutTx:
 		// Verify the signatures
 		_, accused := s.BondedValidators.GetByAddress(tx.Address)
 		if accused == nil {
 			_, accused = s.UnbondingValidators.GetByAddress(tx.Address)
 			if accused == nil {
-				return blk.ErrTxInvalidAddress
+				return types.ErrTxInvalidAddress
 			}
 		}
 		voteASignBytes := account.SignBytes(&tx.VoteA)
 		voteBSignBytes := account.SignBytes(&tx.VoteB)
 		if !accused.PubKey.VerifyBytes(voteASignBytes, tx.VoteA.Signature) ||
 			!accused.PubKey.VerifyBytes(voteBSignBytes, tx.VoteB.Signature) {
-			return blk.ErrTxInvalidSignature
+			return types.ErrTxInvalidSignature
 		}
 
 		// Verify equivocation
@@ -520,10 +520,10 @@ func (s *State) ExecTx(tx_ blk.Tx, runCall bool) error {
 		if tx.VoteA.Height != tx.VoteB.Height {
 			return errors.New("DupeoutTx heights don't match")
 		}
-		if tx.VoteA.Type == blk.VoteTypeCommit && tx.VoteA.Round < tx.VoteB.Round {
+		if tx.VoteA.Type == types.VoteTypeCommit && tx.VoteA.Round < tx.VoteB.Round {
 			// Check special case (not an error, validator must be slashed!)
 			// Validators should not sign another vote after committing.
-		} else if tx.VoteB.Type == blk.VoteTypeCommit && tx.VoteB.Round < tx.VoteA.Round {
+		} else if tx.VoteB.Type == types.VoteTypeCommit && tx.VoteB.Round < tx.VoteA.Round {
 			// We need to check both orderings of the votes
 		} else {
 			if tx.VoteA.Round != tx.VoteB.Round {
@@ -619,7 +619,7 @@ func (s *State) destroyValidator(val *Validator) {
 
 // NOTE: If an error occurs during block execution, state will be left
 // at an invalid state.  Copy the state before calling AppendBlock!
-func (s *State) AppendBlock(block *blk.Block, blockPartsHeader blk.PartSetHeader) error {
+func (s *State) AppendBlock(block *types.Block, blockPartsHeader types.PartSetHeader) error {
 	err := s.appendBlock(block, blockPartsHeader)
 	if err != nil {
 		return err
@@ -633,9 +633,9 @@ func (s *State) AppendBlock(block *blk.Block, blockPartsHeader blk.PartSetHeader
 	return nil
 }
 
-func (s *State) SetBlockStateHash(block *blk.Block) error {
+func (s *State) SetBlockStateHash(block *types.Block) error {
 	sCopy := s.Copy()
-	err := sCopy.appendBlock(block, blk.PartSetHeader{})
+	err := sCopy.appendBlock(block, types.PartSetHeader{})
 	if err != nil {
 		return err
 	}
@@ -647,7 +647,7 @@ func (s *State) SetBlockStateHash(block *blk.Block) error {
 // Appends the block, does not check block.StateHash
 // NOTE: If an error occurs during block execution, state will be left
 // at an invalid state.  Copy the state before calling appendBlock!
-func (s *State) appendBlock(block *blk.Block, blockPartsHeader blk.PartSetHeader) error {
+func (s *State) appendBlock(block *types.Block, blockPartsHeader types.PartSetHeader) error {
 	// Basic block validation.
 	err := block.ValidateBasic(s.LastBlockHeight, s.LastBlockHash, s.LastBlockParts, s.LastBlockTime)
 	if err != nil {
@@ -670,10 +670,10 @@ func (s *State) appendBlock(block *blk.Block, blockPartsHeader blk.PartSetHeader
 			if commit.IsZero() {
 				return false
 			} else {
-				vote := &blk.Vote{
+				vote := &types.Vote{
 					Height:     block.Height - 1,
 					Round:      commit.Round,
-					Type:       blk.VoteTypeCommit,
+					Type:       types.VoteTypeCommit,
 					BlockHash:  block.LastBlockHash,
 					BlockParts: block.LastBlockParts,
 				}
diff --git a/state/state_test.go b/state/state_test.go
index 63bd0c470..da7960a77 100644
--- a/state/state_test.go
+++ b/state/state_test.go
@@ -3,8 +3,8 @@ package state
 import (
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
 	"github.com/tendermint/tendermint/config"
+	"github.com/tendermint/tendermint/types"
 
 	"bytes"
 	"testing"
@@ -52,9 +52,9 @@ func TestCopyState(t *testing.T) {
 	}
 }
 
-func makeBlock(t *testing.T, state *State, commits []blk.Commit, txs []blk.Tx) *blk.Block {
-	block := &blk.Block{
-		Header: &blk.Header{
+func makeBlock(t *testing.T, state *State, commits []types.Commit, txs []types.Tx) *types.Block {
+	block := &types.Block{
+		Header: &types.Header{
 			Network:        config.App().GetString("Network"),
 			Height:         state.LastBlockHeight + 1,
 			Time:           state.LastBlockTime.Add(time.Minute),
@@ -64,10 +64,10 @@ func makeBlock(t *testing.T, state *State, commits []blk.Commit, txs []blk.Tx) *
 			LastBlockParts: state.LastBlockParts,
 			StateHash:      nil,
 		},
-		Validation: &blk.Validation{
+		Validation: &types.Validation{
 			Commits: commits,
 		},
-		Data: &blk.Data{
+		Data: &types.Data{
 			Txs: txs,
 		},
 	}
@@ -91,7 +91,7 @@ func TestGenesisSaveLoad(t *testing.T) {
 
 	// Make complete block and blockParts
 	block := makeBlock(t, s0, nil, nil)
-	blockParts := blk.NewPartSetFromData(binary.BinaryBytes(block))
+	blockParts := types.NewPartSetFromData(binary.BinaryBytes(block))
 
 	// Now append the block to s0.
 	err := s0.AppendBlock(block, blockParts.Header())
@@ -157,18 +157,18 @@ func TestTxSequence(t *testing.T) {
 	acc1 := state.GetAccount(privAccounts[1].PubKey.Address())
 
 	// Try executing a SendTx with various sequence numbers.
-	makeSendTx := func(sequence uint) *blk.SendTx {
-		return &blk.SendTx{
-			Inputs: []*blk.TxInput{
-				&blk.TxInput{
+	makeSendTx := func(sequence uint) *types.SendTx {
+		return &types.SendTx{
+			Inputs: []*types.TxInput{
+				&types.TxInput{
 					Address:  acc0.Address,
 					Amount:   1,
 					Sequence: sequence,
 					PubKey:   acc0PubKey,
 				},
 			},
-			Outputs: []*blk.TxOutput{
-				&blk.TxOutput{
+			Outputs: []*types.TxOutput{
+				&types.TxOutput{
 					Address: acc1.Address,
 					Amount:  1,
 				},
@@ -224,17 +224,17 @@ func TestTxs(t *testing.T) {
 	// SendTx.
 	{
 		state := state.Copy()
-		tx := &blk.SendTx{
-			Inputs: []*blk.TxInput{
-				&blk.TxInput{
+		tx := &types.SendTx{
+			Inputs: []*types.TxInput{
+				&types.TxInput{
 					Address:  acc0.Address,
 					Amount:   1,
 					Sequence: acc0.Sequence + 1,
 					PubKey:   acc0PubKey,
 				},
 			},
-			Outputs: []*blk.TxOutput{
-				&blk.TxOutput{
+			Outputs: []*types.TxOutput{
+				&types.TxOutput{
 					Address: acc1.Address,
 					Amount:  1,
 				},
@@ -261,18 +261,18 @@ func TestTxs(t *testing.T) {
 	// BondTx.
 	{
 		state := state.Copy()
-		tx := &blk.BondTx{
+		tx := &types.BondTx{
 			PubKey: acc0PubKey.(account.PubKeyEd25519),
-			Inputs: []*blk.TxInput{
-				&blk.TxInput{
+			Inputs: []*types.TxInput{
+				&types.TxInput{
 					Address:  acc0.Address,
 					Amount:   1,
 					Sequence: acc0.Sequence + 1,
 					PubKey:   acc0PubKey,
 				},
 			},
-			UnbondTo: []*blk.TxOutput{
-				&blk.TxOutput{
+			UnbondTo: []*types.TxOutput{
+				&types.TxOutput{
 					Address: acc0.Address,
 					Amount:  1,
 				},
@@ -317,18 +317,18 @@ func TestAddValidator(t *testing.T) {
 
 	// The first privAccount will become a validator
 	acc0 := privAccounts[0]
-	bondTx := &blk.BondTx{
+	bondTx := &types.BondTx{
 		PubKey: acc0.PubKey.(account.PubKeyEd25519),
-		Inputs: []*blk.TxInput{
-			&blk.TxInput{
+		Inputs: []*types.TxInput{
+			&types.TxInput{
 				Address:  acc0.Address,
 				Amount:   1000,
 				Sequence: 1,
 				PubKey:   acc0.PubKey,
 			},
 		},
-		UnbondTo: []*blk.TxOutput{
-			&blk.TxOutput{
+		UnbondTo: []*types.TxOutput{
+			&types.TxOutput{
 				Address: acc0.Address,
 				Amount:  1000,
 			},
@@ -337,8 +337,8 @@ func TestAddValidator(t *testing.T) {
 	bondTx.Inputs[0].Signature = acc0.Sign(bondTx)
 
 	// Make complete block and blockParts
-	block0 := makeBlock(t, s0, nil, []blk.Tx{bondTx})
-	block0Parts := blk.NewPartSetFromData(binary.BinaryBytes(block0))
+	block0 := makeBlock(t, s0, nil, []types.Tx{bondTx})
+	block0Parts := types.NewPartSetFromData(binary.BinaryBytes(block0))
 
 	// Sanity check
 	if s0.BondedValidators.Size() != 1 {
@@ -361,25 +361,25 @@ func TestAddValidator(t *testing.T) {
 
 	// The validation for the next block should only require 1 signature
 	// (the new validator wasn't active for block0)
-	commit0 := &blk.Vote{
+	commit0 := &types.Vote{
 		Height:     1,
 		Round:      0,
-		Type:       blk.VoteTypeCommit,
+		Type:       types.VoteTypeCommit,
 		BlockHash:  block0.Hash(),
 		BlockParts: block0Parts.Header(),
 	}
 	privValidators[0].SignVote(commit0)
 
 	block1 := makeBlock(t, s0,
-		[]blk.Commit{
-			blk.Commit{
+		[]types.Commit{
+			types.Commit{
 				Address:   privValidators[0].Address,
 				Round:     0,
 				Signature: commit0.Signature,
 			},
 		}, nil,
 	)
-	block1Parts := blk.NewPartSetFromData(binary.BinaryBytes(block1))
+	block1Parts := types.NewPartSetFromData(binary.BinaryBytes(block1))
 	err = s0.AppendBlock(block1, block1Parts.Header())
 	if err != nil {
 		t.Error("Error appending secondary block:", err)
diff --git a/state/test.go b/state/test.go
index 05b079ec0..49ba0d5e3 100644
--- a/state/test.go
+++ b/state/test.go
@@ -5,9 +5,9 @@ import (
 	"sort"
 
 	"github.com/tendermint/tendermint/account"
-	blk "github.com/tendermint/tendermint/block"
 	. "github.com/tendermint/tendermint/common"
 	dbm "github.com/tendermint/tendermint/db"
+	"github.com/tendermint/tendermint/types"
 
 	"io/ioutil"
 	"os"
@@ -46,7 +46,7 @@ func RandValidator(randBonded bool, minBonded uint64) (*ValidatorInfo, *Validato
 	valInfo := &ValidatorInfo{
 		Address: privVal.Address,
 		PubKey:  privVal.PubKey,
-		UnbondTo: []*blk.TxOutput{&blk.TxOutput{
+		UnbondTo: []*types.TxOutput{&types.TxOutput{
 			Amount:  bonded,
 			Address: privVal.Address,
 		}},
diff --git a/state/validator.go b/state/validator.go
index c0181f4e0..17cbeb5a5 100644
--- a/state/validator.go
+++ b/state/validator.go
@@ -7,14 +7,14 @@ import (
 
 	"github.com/tendermint/tendermint/account"
 	"github.com/tendermint/tendermint/binary"
-	blk "github.com/tendermint/tendermint/block"
+	"github.com/tendermint/tendermint/types"
 )
 
 // Persistent (mostly) static data for each Validator
 type ValidatorInfo struct {
 	Address         []byte
 	PubKey          account.PubKeyEd25519
-	UnbondTo        []*blk.TxOutput
+	UnbondTo        []*types.TxOutput
 	FirstBondHeight uint
 	FirstBondAmount uint64
 
diff --git a/block/README.md b/types/README.md
similarity index 100%
rename from block/README.md
rename to types/README.md
diff --git a/block/block.go b/types/block.go
similarity index 95%
rename from block/block.go
rename to types/block.go
index bfa8c28f4..d56f4e467 100644
--- a/block/block.go
+++ b/types/block.go
@@ -1,4 +1,4 @@
-package block
+package types
 
 import (
 	"bytes"
@@ -54,6 +54,9 @@ func (b *Block) ValidateBasic(lastBlockHeight uint, lastBlockHash []byte,
 }
 
 func (b *Block) Hash() []byte {
+	if b.Header == nil || b.Validation == nil || b.Data == nil {
+		return nil
+	}
 	hashes := [][]byte{
 		b.Header.Hash(),
 		b.Validation.Hash(),
@@ -81,6 +84,9 @@ func (b *Block) String() string {
 }
 
 func (b *Block) StringIndented(indent string) string {
+	if b == nil {
+		return "nil-Block"
+	}
 	return fmt.Sprintf(`Block{
 %s  %v
 %s  %v
@@ -126,6 +132,9 @@ func (h *Header) Hash() []byte {
 }
 
 func (h *Header) StringIndented(indent string) string {
+	if h == nil {
+		return "nil-Header"
+	}
 	return fmt.Sprintf(`Header{
 %s  Network:        %v
 %s  Height:         %v
@@ -212,6 +221,9 @@ func (v *Validation) Hash() []byte {
 }
 
 func (v *Validation) StringIndented(indent string) string {
+	if v == nil {
+		return "nil-Validation"
+	}
 	commitStrings := make([]string, len(v.Commits))
 	for i, commit := range v.Commits {
 		commitStrings[i] = commit.String()
@@ -254,6 +266,9 @@ func (data *Data) Hash() []byte {
 }
 
 func (data *Data) StringIndented(indent string) string {
+	if data == nil {
+		return "nil-Data"
+	}
 	txStrings := make([]string, len(data.Txs))
 	for i, tx := range data.Txs {
 		txStrings[i] = fmt.Sprintf("Tx:%v", tx)
diff --git a/block/log.go b/types/log.go
similarity index 50%
rename from block/log.go
rename to types/log.go
index bdc316758..fed0c559f 100644
--- a/block/log.go
+++ b/types/log.go
@@ -1,7 +1,7 @@
-package block
+package types
 
 import (
 	"github.com/tendermint/tendermint/logger"
 )
 
-var log = logger.New("module", "block")
+var log = logger.New("module", "types")
diff --git a/block/part_set.go b/types/part_set.go
similarity index 99%
rename from block/part_set.go
rename to types/part_set.go
index 046b95430..d403809d1 100644
--- a/block/part_set.go
+++ b/types/part_set.go
@@ -1,4 +1,4 @@
-package block
+package types
 
 import (
 	"bytes"
diff --git a/block/part_set_test.go b/types/part_set_test.go
similarity index 99%
rename from block/part_set_test.go
rename to types/part_set_test.go
index ebfda4524..d27a85c4d 100644
--- a/block/part_set_test.go
+++ b/types/part_set_test.go
@@ -1,4 +1,4 @@
-package block
+package types
 
 import (
 	"bytes"
diff --git a/block/store.go b/types/store.go
similarity index 99%
rename from block/store.go
rename to types/store.go
index e49083ca1..3afc8cb58 100644
--- a/block/store.go
+++ b/types/store.go
@@ -1,4 +1,4 @@
-package block
+package types
 
 import (
 	"bytes"
diff --git a/block/tx.go b/types/tx.go
similarity index 99%
rename from block/tx.go
rename to types/tx.go
index f03d3d945..1df6f6be1 100644
--- a/block/tx.go
+++ b/types/tx.go
@@ -1,4 +1,4 @@
-package block
+package types
 
 import (
 	"errors"
diff --git a/block/vote.go b/types/vote.go
similarity index 99%
rename from block/vote.go
rename to types/vote.go
index b3425cf90..3e3a30e08 100644
--- a/block/vote.go
+++ b/types/vote.go
@@ -1,4 +1,4 @@
-package block
+package types
 
 import (
 	"errors"