diff --git a/Makefile b/Makefile
index ac1956dd..ea66d820 100644
--- a/Makefile
+++ b/Makefile
@@ -43,6 +43,10 @@ get_deps:
 		grep -v /vendor/ | sort | uniq | \
 		xargs go get
 
+get_vendor_deps:
+	go get github.com/Masterminds/glide
+	glide install
+
 update_deps:
 	go get -d -u github.com/tendermint/tendermint/...
 
diff --git a/circle.yml b/circle.yml
index f022d5a6..98dd2228 100644
--- a/circle.yml
+++ b/circle.yml
@@ -16,8 +16,8 @@ checkout:
 
 dependencies:
   override:
-    - "cd $REPO && make get_deps"
+    - "cd $REPO && make get_vendor_deps"
 
 test:
   override:
-    - "cd $REPO && make test"
+    - "cd $REPO && make test_race"
diff --git a/config/tendermint_test/config.go b/config/tendermint_test/config.go
index 689ba794..c53f8bfb 100644
--- a/config/tendermint_test/config.go
+++ b/config/tendermint_test/config.go
@@ -86,13 +86,13 @@ func ResetConfig(localPath string) cfg.Config {
 
 	mapConfig.SetDefault("block_size", 10000)
 	mapConfig.SetDefault("disable_data_hash", false)
-	mapConfig.SetDefault("timeout_propose", 100)
-	mapConfig.SetDefault("timeout_propose_delta", 1)
-	mapConfig.SetDefault("timeout_prevote", 1)
-	mapConfig.SetDefault("timeout_prevote_delta", 1)
-	mapConfig.SetDefault("timeout_precommit", 1)
-	mapConfig.SetDefault("timeout_precommit_delta", 1)
-	mapConfig.SetDefault("timeout_commit", 1)
+	mapConfig.SetDefault("timeout_propose", 3000)
+	mapConfig.SetDefault("timeout_propose_delta", 1000)
+	mapConfig.SetDefault("timeout_prevote", 2000)
+	mapConfig.SetDefault("timeout_prevote_delta", 1000)
+	mapConfig.SetDefault("timeout_precommit", 2000)
+	mapConfig.SetDefault("timeout_precommit_delta", 1000)
+	mapConfig.SetDefault("timeout_commit", 1000)
 	mapConfig.SetDefault("mempool_recheck", true)
 	mapConfig.SetDefault("mempool_recheck_empty", true)
 	mapConfig.SetDefault("mempool_broadcast", true)
diff --git a/consensus/common_test.go b/consensus/common_test.go
index a7fce7d1..693edbca 100644
--- a/consensus/common_test.go
+++ b/consensus/common_test.go
@@ -99,18 +99,18 @@ func changeProposer(t *testing.T, perspectiveOf *ConsensusState, newProposer *va
 	_, v1 := perspectiveOf.Validators.GetByAddress(perspectiveOf.privValidator.Address)
 	v1.Accum, v1.VotingPower = 0, 0
 	if updated := perspectiveOf.Validators.Update(v1); !updated {
-		t.Fatal("failed to update validator")
+		panic("failed to update validator")
 	}
 	_, v2 := perspectiveOf.Validators.GetByAddress(newProposer.Address)
 	v2.Accum, v2.VotingPower = 100, 100
 	if updated := perspectiveOf.Validators.Update(v2); !updated {
-		t.Fatal("failed to update validator")
+		panic("failed to update validator")
 	}
 
 	// make the proposal
 	propBlock, _ := perspectiveOf.createProposalBlock()
 	if propBlock == nil {
-		t.Fatal("Failed to create proposal block with cs2")
+		panic("Failed to create proposal block with cs2")
 	}
 	return propBlock
 }
@@ -120,7 +120,7 @@ func fixVotingPower(t *testing.T, cs1 *ConsensusState, addr2 []byte) {
 	_, v2 := cs1.Validators.GetByAddress(addr2)
 	v1.Accum, v1.VotingPower = v2.Accum, v2.VotingPower
 	if updated := cs1.Validators.Update(v1); !updated {
-		t.Fatal("failed to update validator")
+		panic("failed to update validator")
 	}
 }
 
@@ -128,13 +128,16 @@ func addVoteToFromMany(to *ConsensusState, votes []*types.Vote, froms ...*valida
 	if len(votes) != len(froms) {
 		panic("len(votes) and len(froms) must match")
 	}
+
 	for i, from := range froms {
 		addVoteToFrom(to, from, votes[i])
 	}
 }
 
 func addVoteToFrom(to *ConsensusState, from *validatorStub, vote *types.Vote) {
+	to.mtx.Lock() // NOTE: wont need this when the vote comes with the index!
 	valIndex, _ := to.Validators.GetByAddress(from.PrivValidator.Address)
+	to.mtx.Unlock()
 
 	to.peerMsgQueue <- msgInfo{Msg: &VoteMessage{valIndex, vote}}
 	// added, err := to.TryAddVote(valIndex, vote, "")
@@ -158,16 +161,32 @@ func signVoteMany(voteType byte, hash []byte, header types.PartSetHeader, vss ..
 }
 
 // add vote to one cs from another
-func signAddVoteToFromMany(voteType byte, to *ConsensusState, hash []byte, header types.PartSetHeader, froms ...*validatorStub) {
+// if voteCh is not nil, read all votes
+func signAddVoteToFromMany(voteType byte, to *ConsensusState, hash []byte, header types.PartSetHeader, voteCh chan interface{}, froms ...*validatorStub) {
+	var wg chan struct{} // when done reading all votes
+	if voteCh != nil {
+		wg = readVotes(voteCh, len(froms))
+	}
 	for _, from := range froms {
 		vote := signVote(from, voteType, hash, header)
 		addVoteToFrom(to, from, vote)
 	}
+
+	if voteCh != nil {
+		<-wg
+	}
 }
 
-func signAddVoteToFrom(voteType byte, to *ConsensusState, from *validatorStub, hash []byte, header types.PartSetHeader) *types.Vote {
+func signAddVoteToFrom(voteType byte, to *ConsensusState, from *validatorStub, hash []byte, header types.PartSetHeader, voteCh chan interface{}) *types.Vote {
+	var wg chan struct{} // when done reading all votes
+	if voteCh != nil {
+		wg = readVotes(voteCh, 1)
+	}
 	vote := signVote(from, voteType, hash, header)
 	addVoteToFrom(to, from, vote)
+	if voteCh != nil {
+		<-wg
+	}
 	return vote
 }
 
@@ -357,6 +376,17 @@ func subscribeToVoter(cs *ConsensusState, addr []byte) chan interface{} {
 	return voteCh
 }
 
+func readVotes(ch chan interface{}, reads int) chan struct{} {
+	wg := make(chan struct{})
+	go func() {
+		for i := 0; i < reads; i++ {
+			<-ch // read the precommit event
+		}
+		close(wg)
+	}()
+	return wg
+}
+
 func randGenesisState(numValidators int, randPower bool, minPower int64) (*sm.State, []*types.PrivValidator) {
 	db := dbm.NewMemDB()
 	genDoc, privValidators := randGenesisDoc(numValidators, randPower, minPower)
diff --git a/consensus/height_vote_set.go b/consensus/height_vote_set.go
index 93fa94e8..583ef3f6 100644
--- a/consensus/height_vote_set.go
+++ b/consensus/height_vote_set.go
@@ -38,18 +38,28 @@ type HeightVoteSet struct {
 
 func NewHeightVoteSet(chainID string, height int, valSet *types.ValidatorSet) *HeightVoteSet {
 	hvs := &HeightVoteSet{
-		chainID:           chainID,
-		height:            height,
-		valSet:            valSet,
-		roundVoteSets:     make(map[int]RoundVoteSet),
-		peerCatchupRounds: make(map[string]int),
+		chainID: chainID,
 	}
-	hvs.addRound(0)
-	hvs.round = 0
+	hvs.Reset(height, valSet)
 	return hvs
 }
 
+func (hvs *HeightVoteSet) Reset(height int, valSet *types.ValidatorSet) {
+	hvs.mtx.Lock()
+	defer hvs.mtx.Unlock()
+
+	hvs.height = height
+	hvs.valSet = valSet
+	hvs.roundVoteSets = make(map[int]RoundVoteSet)
+	hvs.peerCatchupRounds = make(map[string]int)
+
+	hvs.addRound(0)
+	hvs.round = 0
+}
+
 func (hvs *HeightVoteSet) Height() int {
+	hvs.mtx.Lock()
+	defer hvs.mtx.Unlock()
 	return hvs.height
 }
 
diff --git a/consensus/height_vote_set_test.go b/consensus/height_vote_set_test.go
index 28502716..b5153259 100644
--- a/consensus/height_vote_set_test.go
+++ b/consensus/height_vote_set_test.go
@@ -1,10 +1,11 @@
 package consensus
 
 import (
+	"testing"
+
+	. "github.com/tendermint/go-common"
 	"github.com/tendermint/tendermint/config/tendermint_test"
 	"github.com/tendermint/tendermint/types"
-
-	"testing"
 )
 
 func init() {
@@ -45,7 +46,7 @@ func makeVoteHR(t *testing.T, height, round int, privVal *types.PrivValidator) *
 	chainID := config.GetString("chain_id")
 	err := privVal.SignVote(chainID, vote)
 	if err != nil {
-		t.Fatalf("Error signing vote: %v", err)
+		panic(Fmt("Error signing vote: %v", err))
 		return nil
 	}
 	return vote
diff --git a/consensus/mempool_test.go b/consensus/mempool_test.go
index 14098b86..2a063be7 100644
--- a/consensus/mempool_test.go
+++ b/consensus/mempool_test.go
@@ -31,7 +31,7 @@ func TestTxConcurrentWithCommit(t *testing.T) {
 			binary.BigEndian.PutUint64(txBytes, uint64(i))
 			err := cs.mempool.CheckTx(txBytes, nil)
 			if err != nil {
-				t.Fatal("Error after CheckTx: %v", err)
+				panic(Fmt("Error after CheckTx: %v", err))
 			}
 			//	time.Sleep(time.Microsecond * time.Duration(rand.Int63n(3000)))
 		}
@@ -41,13 +41,13 @@ func TestTxConcurrentWithCommit(t *testing.T) {
 	go appendTxsRange(0, NTxs)
 
 	startTestRound(cs, height, round)
-	ticker := time.NewTicker(time.Second * 5)
+	ticker := time.NewTicker(time.Second * 20)
 	for nTxs := 0; nTxs < NTxs; {
 		select {
 		case b := <-newBlockCh:
 			nTxs += b.(types.EventDataNewBlock).Block.Header.NumTxs
 		case <-ticker.C:
-			t.Fatal("Timed out waiting to commit blocks with transactions")
+			panic("Timed out waiting to commit blocks with transactions")
 		}
 	}
 }
diff --git a/consensus/replay_test.go b/consensus/replay_test.go
index d46f68cd..46e862ed 100644
--- a/consensus/replay_test.go
+++ b/consensus/replay_test.go
@@ -6,6 +6,7 @@ import (
 	"testing"
 	"time"
 
+	. "github.com/tendermint/go-common"
 	"github.com/tendermint/tendermint/types"
 )
 
@@ -59,12 +60,12 @@ func TestReplayCatchup(t *testing.T) {
 	// write the needed wal to file
 	f, err := ioutil.TempFile(os.TempDir(), "replay_test_")
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	name := f.Name()
 	_, err = f.WriteString(testLog)
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	f.Close()
 
@@ -83,14 +84,14 @@ func TestReplayCatchup(t *testing.T) {
 	// open wal and run catchup messages
 	openWAL(t, cs, name)
 	if err := cs.catchupReplay(cs.Height); err != nil {
-		t.Fatalf("Error on catchup replay %v", err)
+		panic(Fmt("Error on catchup replay %v", err))
 	}
 
 	after := time.After(time.Second * 15)
 	select {
 	case <-newBlockCh:
 	case <-after:
-		t.Fatal("Timed out waiting for new block")
+		panic("Timed out waiting for new block")
 	}
 }
 
@@ -98,7 +99,7 @@ func openWAL(t *testing.T, cs *ConsensusState, file string) {
 	// open the wal
 	wal, err := NewWAL(file, config.GetBool("cswal_light"))
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	wal.exists = true
 	cs.wal = wal
diff --git a/consensus/state.go b/consensus/state.go
index 37209f68..50488f8d 100644
--- a/consensus/state.go
+++ b/consensus/state.go
@@ -268,7 +268,8 @@ func (cs *ConsensusState) SetEventSwitch(evsw *events.EventSwitch) {
 }
 
 func (cs *ConsensusState) String() string {
-	return Fmt("ConsensusState(H:%v R:%v S:%v", cs.Height, cs.Round, cs.Step)
+	// better not to access shared variables
+	return Fmt("ConsensusState") //(H:%v R:%v S:%v", cs.Height, cs.Round, cs.Step)
 }
 
 func (cs *ConsensusState) GetState() *sm.State {
@@ -322,6 +323,7 @@ func (cs *ConsensusState) startRoutines(maxSteps int) {
 
 func (cs *ConsensusState) OnStop() {
 	cs.QuitService.OnStop()
+
 	if cs.wal != nil && cs.IsRunning() {
 		cs.wal.Wait()
 	}
@@ -1214,10 +1216,13 @@ func (cs *ConsensusState) finalizeCommit(height int) {
 	// Create a copy of the state for staging
 	stateCopy := cs.state.Copy()
 
+	// event cache for txs
+	eventCache := events.NewEventCache(cs.evsw)
+
 	// Run the block on the State:
 	// + update validator sets
 	// + run txs on the proxyAppConn
-	err := stateCopy.ExecBlock(cs.evsw, cs.proxyAppConn, block, blockParts.Header())
+	err := stateCopy.ExecBlock(eventCache, cs.proxyAppConn, block, blockParts.Header())
 	if err != nil {
 		// TODO: handle this gracefully.
 		PanicQ(Fmt("Exec failed for application: %v", err))
@@ -1230,6 +1235,9 @@ func (cs *ConsensusState) finalizeCommit(height int) {
 		PanicQ(Fmt("Commit failed for application: %v", err))
 	}
 
+	// txs committed, bad ones removed from mepool; fire events
+	eventCache.Flush()
+
 	// Save to blockStore.
 	if cs.blockStore.Height() < block.Height {
 		precommits := cs.Votes.Precommits(cs.CommitRound)
diff --git a/consensus/state_test.go b/consensus/state_test.go
index 797e5d04..9a8d6090 100644
--- a/consensus/state_test.go
+++ b/consensus/state_test.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/tendermint/tendermint/config/tendermint_test"
 	//"github.com/tendermint/go-events"
+	. "github.com/tendermint/go-common"
 	"github.com/tendermint/tendermint/types"
 )
 
@@ -67,21 +68,21 @@ func TestProposerSelection0(t *testing.T) {
 	// lets commit a block and ensure proposer for the next height is correct
 	prop := cs1.GetRoundState().Validators.Proposer()
 	if !bytes.Equal(prop.Address, cs1.privValidator.Address) {
-		t.Fatalf("expected proposer to be validator %d. Got %X", 0, prop.Address)
+		panic(Fmt("expected proposer to be validator %d. Got %X", 0, prop.Address))
 	}
 
 	// wait for complete proposal
 	<-proposalCh
 
 	rs := cs1.GetRoundState()
-	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), vss[1:]...)
+	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), nil, vss[1:]...)
 
 	// wait for new round so next validator is set
 	<-newRoundCh
 
 	prop = cs1.GetRoundState().Validators.Proposer()
 	if !bytes.Equal(prop.Address, vss[1].Address) {
-		t.Fatalf("expected proposer to be validator %d. Got %X", 1, prop.Address)
+		panic(Fmt("expected proposer to be validator %d. Got %X", 1, prop.Address))
 	}
 }
 
@@ -102,11 +103,11 @@ func TestProposerSelection2(t *testing.T) {
 	for i := 0; i < len(vss); i++ {
 		prop := cs1.GetRoundState().Validators.Proposer()
 		if !bytes.Equal(prop.Address, vss[(i+2)%len(vss)].Address) {
-			t.Fatalf("expected proposer to be validator %d. Got %X", (i+2)%len(vss), prop.Address)
+			panic(Fmt("expected proposer to be validator %d. Got %X", (i+2)%len(vss), prop.Address))
 		}
 
 		rs := cs1.GetRoundState()
-		signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, rs.ProposalBlockParts.Header(), vss[1:]...)
+		signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, rs.ProposalBlockParts.Header(), nil, vss[1:]...)
 		<-newRoundCh // wait for the new round event each round
 
 		incrementRound(vss[1:]...)
@@ -130,7 +131,7 @@ func TestEnterProposeNoPrivValidator(t *testing.T) {
 	select {
 	case <-timeoutCh:
 	case <-ticker.C:
-		t.Fatal("Expected EnterPropose to timeout")
+		panic("Expected EnterPropose to timeout")
 
 	}
 
@@ -170,7 +171,7 @@ func TestEnterProposeYesPrivValidator(t *testing.T) {
 	ticker := time.NewTicker(cs.timeoutParams.ensureProposeTimeout())
 	select {
 	case <-timeoutCh:
-		t.Fatal("Expected EnterPropose not to timeout")
+		panic("Expected EnterPropose not to timeout")
 	case <-ticker.C:
 
 	}
@@ -200,7 +201,7 @@ func TestBadProposal(t *testing.T) {
 	propBlockParts := propBlock.MakePartSet()
 	proposal := types.NewProposal(cs2.Height, round, propBlockParts.Header(), -1)
 	if err := cs2.SignProposal(config.GetString("chain_id"), proposal); err != nil {
-		t.Fatal("failed to sign bad proposal", err)
+		panic("failed to sign bad proposal: " + err.Error())
 	}
 
 	// set the proposal block
@@ -218,14 +219,13 @@ func TestBadProposal(t *testing.T) {
 	validatePrevote(t, cs1, round, vss[0], nil)
 
 	// add bad prevote from cs2 and wait for it
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, propBlock.Hash(), propBlock.MakePartSet().Header())
-	<-voteCh
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, propBlock.Hash(), propBlock.MakePartSet().Header(), voteCh)
 
 	// wait for precommit
 	<-voteCh
 
 	validatePrecommit(t, cs1, round, 0, vss[0], nil, nil)
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, propBlock.Hash(), propBlock.MakePartSet().Header())
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, propBlock.Hash(), propBlock.MakePartSet().Header(), voteCh)
 }
 
 //----------------------------------------------------------------------------------------------------
@@ -292,12 +292,11 @@ func TestFullRound2(t *testing.T) {
 	<-voteCh // prevote
 
 	// we should be stuck in limbo waiting for more prevotes
-
-	propBlockHash, propPartsHeader := cs1.ProposalBlock.Hash(), cs1.ProposalBlockParts.Header()
+	rs := cs1.GetRoundState()
+	propBlockHash, propPartsHeader := rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header()
 
 	// prevote arrives from cs2:
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, propBlockHash, propPartsHeader)
-	<-voteCh
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, propBlockHash, propPartsHeader, voteCh)
 
 	<-voteCh //precommit
 
@@ -307,8 +306,7 @@ func TestFullRound2(t *testing.T) {
 	// we should be stuck in limbo waiting for more precommits
 
 	// precommit arrives from cs2:
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, propBlockHash, propPartsHeader)
-	<-voteCh
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, propBlockHash, propPartsHeader, voteCh)
 
 	// wait to finish commit, propose in next height
 	<-newBlockCh
@@ -346,8 +344,7 @@ func TestLockNoPOL(t *testing.T) {
 
 	// we should now be stuck in limbo forever, waiting for more prevotes
 	// prevote arrives from cs2:
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, cs1.ProposalBlock.Hash(), cs1.ProposalBlockParts.Header())
-	<-voteCh // prevote
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), voteCh)
 
 	<-voteCh // precommit
 
@@ -360,8 +357,7 @@ func TestLockNoPOL(t *testing.T) {
 	hash := make([]byte, len(theBlockHash))
 	copy(hash, theBlockHash)
 	hash[0] = byte((hash[0] + 1) % 255)
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header())
-	<-voteCh // precommit
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header(), voteCh)
 
 	// (note we're entering precommit for a second time this round)
 	// but with invalid args. then we enterPrecommitWait, and the timeout to new round
@@ -382,7 +378,7 @@ func TestLockNoPOL(t *testing.T) {
 	rs = re.(types.EventDataRoundState).RoundState.(*RoundState)
 
 	if rs.ProposalBlock != nil {
-		t.Fatal("Expected proposal block to be nil")
+		panic("Expected proposal block to be nil")
 	}
 
 	// wait to finish prevote
@@ -392,8 +388,7 @@ func TestLockNoPOL(t *testing.T) {
 	validatePrevote(t, cs1, 1, vss[0], rs.LockedBlock.Hash())
 
 	// add a conflicting prevote from the other validator
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header())
-	<-voteCh
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header(), voteCh)
 
 	// now we're going to enter prevote again, but with invalid args
 	// and then prevote wait, which should timeout. then wait for precommit
@@ -407,8 +402,7 @@ func TestLockNoPOL(t *testing.T) {
 
 	// add conflicting precommit from cs2
 	// NOTE: in practice we should never get to a point where there are precommits for different blocks at the same round
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header())
-	<-voteCh
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header(), voteCh)
 
 	// (note we're entering precommit for a second time this round, but with invalid args
 	// then we enterPrecommitWait and timeout into NewRound
@@ -427,29 +421,27 @@ func TestLockNoPOL(t *testing.T) {
 
 	// now we're on a new round and are the proposer
 	if !bytes.Equal(rs.ProposalBlock.Hash(), rs.LockedBlock.Hash()) {
-		t.Fatalf("Expected proposal block to be locked block. Got %v, Expected %v", rs.ProposalBlock, rs.LockedBlock)
+		panic(Fmt("Expected proposal block to be locked block. Got %v, Expected %v", rs.ProposalBlock, rs.LockedBlock))
 	}
 
 	<-voteCh // prevote
 
 	validatePrevote(t, cs1, 2, vss[0], rs.LockedBlock.Hash())
 
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header())
-	<-voteCh
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header(), voteCh)
 
 	<-timeoutWaitCh // prevote wait
 	<-voteCh        // precommit
 
-	validatePrecommit(t, cs1, 2, 0, vss[0], nil, theBlockHash)                                          // precommit nil but be locked on proposal
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header()) // NOTE: conflicting precommits at same height
-	<-voteCh
+	validatePrecommit(t, cs1, 2, 0, vss[0], nil, theBlockHash)                                                  // precommit nil but be locked on proposal
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, hash, rs.ProposalBlock.MakePartSet().Header(), voteCh) // NOTE: conflicting precommits at same height
 
 	<-timeoutWaitCh
 
 	// before we time out into new round, set next proposal block
 	prop, propBlock := decideProposal(cs1, cs2, cs2.Height, cs2.Round+1)
 	if prop == nil || propBlock == nil {
-		t.Fatal("Failed to create proposal block with cs2")
+		panic("Failed to create proposal block with cs2")
 	}
 
 	incrementRound(cs2)
@@ -470,15 +462,13 @@ func TestLockNoPOL(t *testing.T) {
 	// prevote for locked block (not proposal)
 	validatePrevote(t, cs1, 0, vss[0], cs1.LockedBlock.Hash())
 
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, propBlock.Hash(), propBlock.MakePartSet().Header())
-	<-voteCh
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, propBlock.Hash(), propBlock.MakePartSet().Header(), voteCh)
 
 	<-timeoutWaitCh
 	<-voteCh
 
-	validatePrecommit(t, cs1, 2, 0, vss[0], nil, theBlockHash)                                               // precommit nil but locked on proposal
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, propBlock.Hash(), propBlock.MakePartSet().Header()) // NOTE: conflicting precommits at same height
-	<-voteCh
+	validatePrecommit(t, cs1, 2, 0, vss[0], nil, theBlockHash)                                                       // precommit nil but locked on proposal
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, propBlock.Hash(), propBlock.MakePartSet().Header(), voteCh) // NOTE: conflicting precommits at same height
 }
 
 // 4 vals, one precommits, other 3 polka at next round, so we unlock and precomit the polka
@@ -510,20 +500,19 @@ func TestLockPOLRelock(t *testing.T) {
 	re := <-proposalCh
 	rs := re.(types.EventDataRoundState).RoundState.(*RoundState)
 	theBlockHash := rs.ProposalBlock.Hash()
+	theBlockPartsHeader := rs.ProposalBlockParts.Header()
 
 	<-voteCh // prevote
 
-	signAddVoteToFromMany(types.VoteTypePrevote, cs1, cs1.ProposalBlock.Hash(), cs1.ProposalBlockParts.Header(), cs2, cs3, cs4)
-	_, _, _ = <-voteCh, <-voteCh, <-voteCh // prevotes
+	signAddVoteToFromMany(types.VoteTypePrevote, cs1, theBlockHash, theBlockPartsHeader, voteCh, cs2, cs3, cs4)
 
 	<-voteCh // our precommit
 	// the proposed block should now be locked and our precommit added
 	validatePrecommit(t, cs1, 0, 0, vss[0], theBlockHash, theBlockHash)
 
 	// add precommits from the rest
-	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, cs2, cs4)
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs3, cs1.ProposalBlock.Hash(), cs1.ProposalBlockParts.Header())
-	_, _, _ = <-voteCh, <-voteCh, <-voteCh // precommits
+	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, voteCh, cs2, cs4)
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs3, theBlockHash, theBlockPartsHeader, voteCh)
 
 	// before we timeout to the new round set the new proposal
 	prop, propBlock := decideProposal(cs1, cs2, cs2.Height, cs2.Round+1)
@@ -560,12 +549,13 @@ func TestLockPOLRelock(t *testing.T) {
 	validatePrevote(t, cs1, 0, vss[0], theBlockHash)
 
 	// now lets add prevotes from everyone else for the new block
-	signAddVoteToFromMany(types.VoteTypePrevote, cs1, propBlockHash, propBlockParts.Header(), cs2, cs3, cs4)
-	_, _, _ = <-voteCh, <-voteCh, <-voteCh // prevotes
+	signAddVoteToFromMany(types.VoteTypePrevote, cs1, propBlockHash, propBlockParts.Header(), voteCh, cs2, cs3, cs4)
 
 	// now either we go to PrevoteWait or Precommit
 	select {
 	case <-timeoutWaitCh: // we're in PrevoteWait, go to Precommit
+		// XXX: there's no guarantee we see the polka, this might be a precommit for nil,
+		// in which case the test fails!
 		<-voteCh
 	case <-voteCh: // we went straight to Precommit
 	}
@@ -573,19 +563,18 @@ func TestLockPOLRelock(t *testing.T) {
 	// we should have unlocked and locked on the new block
 	validatePrecommit(t, cs1, 1, 1, vss[0], propBlockHash, propBlockHash)
 
-	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, propBlockHash, propBlockParts.Header(), cs2, cs3)
-	_, _ = <-voteCh, <-voteCh
+	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, propBlockHash, propBlockParts.Header(), voteCh, cs2, cs3)
 
 	be := <-newBlockCh
 	b := be.(types.EventDataNewBlockHeader)
 	re = <-newRoundCh
 	rs = re.(types.EventDataRoundState).RoundState.(*RoundState)
 	if rs.Height != 2 {
-		t.Fatal("Expected height to increment")
+		panic("Expected height to increment")
 	}
 
 	if !bytes.Equal(b.Header.Hash(), propBlockHash) {
-		t.Fatal("Expected new block to be proposal block")
+		panic("Expected new block to be proposal block")
 	}
 }
 
@@ -618,16 +607,18 @@ func TestLockPOLUnlock(t *testing.T) {
 
 	<-voteCh // prevote
 
-	signAddVoteToFromMany(types.VoteTypePrevote, cs1, cs1.ProposalBlock.Hash(), cs1.ProposalBlockParts.Header(), cs2, cs3, cs4)
+	signAddVoteToFromMany(types.VoteTypePrevote, cs1, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), nil, cs2, cs3, cs4)
 
 	<-voteCh //precommit
 
 	// the proposed block should now be locked and our precommit added
 	validatePrecommit(t, cs1, 0, 0, vss[0], theBlockHash, theBlockHash)
 
+	rs = cs1.GetRoundState()
+
 	// add precommits from the rest
-	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, cs2, cs4)
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs3, cs1.ProposalBlock.Hash(), cs1.ProposalBlockParts.Header())
+	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, nil, cs2, cs4)
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs3, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), nil)
 
 	// before we time out into new round, set next proposal block
 	prop, propBlock := decideProposal(cs1, cs2, cs2.Height, cs2.Round+1)
@@ -663,7 +654,7 @@ func TestLockPOLUnlock(t *testing.T) {
 	<-voteCh
 	validatePrevote(t, cs1, 0, vss[0], lockedBlockHash)
 	// now lets add prevotes from everyone else for nil (a polka!)
-	signAddVoteToFromMany(types.VoteTypePrevote, cs1, nil, types.PartSetHeader{}, cs2, cs3, cs4)
+	signAddVoteToFromMany(types.VoteTypePrevote, cs1, nil, types.PartSetHeader{}, nil, cs2, cs3, cs4)
 
 	// the polka makes us unlock and precommit nil
 	<-unlockCh
@@ -673,7 +664,7 @@ func TestLockPOLUnlock(t *testing.T) {
 	// NOTE: since we don't relock on nil, the lock round is 0
 	validatePrecommit(t, cs1, 1, 0, vss[0], nil, nil)
 
-	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, cs2, cs3)
+	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, nil, cs2, cs3)
 	<-newRoundCh
 }
 
@@ -711,13 +702,13 @@ func TestLockPOLSafety1(t *testing.T) {
 		_, v1 := cs1.Validators.GetByAddress(vss[0].Address)
 		v1.VotingPower = 1
 		if updated := cs1.Validators.Update(v1); !updated {
-			t.Fatal("failed to update validator")
+			panic("failed to update validator")
 		}*/
 
 	log.Warn("old prop", "hash", fmt.Sprintf("%X", propBlock.Hash()))
 
 	// we do see them precommit nil
-	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, cs2, cs3, cs4)
+	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, nil, cs2, cs3, cs4)
 
 	prop, propBlock := decideProposal(cs1, cs2, cs2.Height, cs2.Round+1)
 	propBlockHash := propBlock.Hash()
@@ -746,7 +737,7 @@ func TestLockPOLSafety1(t *testing.T) {
 	rs = re.(types.EventDataRoundState).RoundState.(*RoundState)
 
 	if rs.LockedBlock != nil {
-		t.Fatal("we should not be locked!")
+		panic("we should not be locked!")
 	}
 	log.Warn("new prop", "hash", fmt.Sprintf("%X", propBlockHash))
 	// go to prevote, prevote for proposal block
@@ -754,14 +745,14 @@ func TestLockPOLSafety1(t *testing.T) {
 	validatePrevote(t, cs1, 1, vss[0], propBlockHash)
 
 	// now we see the others prevote for it, so we should lock on it
-	signAddVoteToFromMany(types.VoteTypePrevote, cs1, propBlockHash, propBlockParts.Header(), cs2, cs3, cs4)
+	signAddVoteToFromMany(types.VoteTypePrevote, cs1, propBlockHash, propBlockParts.Header(), nil, cs2, cs3, cs4)
 
 	<-voteCh // precommit
 
 	// we should have precommitted
 	validatePrecommit(t, cs1, 1, 1, vss[0], propBlockHash, propBlockHash)
 
-	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, cs2, cs3)
+	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, nil, cs2, cs3)
 
 	<-timeoutWaitCh
 
@@ -840,15 +831,15 @@ func TestLockPOLSafety2(t *testing.T) {
 
 	<-voteCh // prevote
 
-	signAddVoteToFromMany(types.VoteTypePrevote, cs1, propBlockHash1, propBlockParts1.Header(), cs2, cs3, cs4)
+	signAddVoteToFromMany(types.VoteTypePrevote, cs1, propBlockHash1, propBlockParts1.Header(), nil, cs2, cs3, cs4)
 
 	<-voteCh // precommit
 	// the proposed block should now be locked and our precommit added
 	validatePrecommit(t, cs1, 1, 1, vss[0], propBlockHash1, propBlockHash1)
 
 	// add precommits from the rest
-	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, cs2, cs4)
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs3, propBlockHash1, propBlockParts1.Header())
+	signAddVoteToFromMany(types.VoteTypePrecommit, cs1, nil, types.PartSetHeader{}, nil, cs2, cs4)
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs3, propBlockHash1, propBlockParts1.Header(), nil)
 
 	incrementRound(cs2, cs3, cs4)
 
@@ -858,7 +849,7 @@ func TestLockPOLSafety2(t *testing.T) {
 	// in round 2 we see the polkad block from round 0
 	newProp := types.NewProposal(height, 2, propBlockParts0.Header(), 0)
 	if err := cs3.SignProposal(config.GetString("chain_id"), newProp); err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	cs1.SetProposalAndBlock(newProp, propBlock0, propBlockParts0, "some peer")
 	addVoteToFromMany(cs1, prevotes, cs2, cs3, cs4) // add the pol votes
@@ -877,7 +868,7 @@ func TestLockPOLSafety2(t *testing.T) {
 
 	select {
 	case <-unlockCh:
-		t.Fatal("validator unlocked using an old polka")
+		panic("validator unlocked using an old polka")
 	case <-voteCh:
 		// prevote our locked block
 	}
@@ -910,9 +901,9 @@ func TestSlashingPrevotes(t *testing.T) {
 
 	// we should now be stuck in limbo forever, waiting for more prevotes
 	// add one for a different block should cause us to go into prevote wait
-	hash := cs1.ProposalBlock.Hash()
+	hash := rs.ProposalBlock.Hash()
 	hash[0] = byte(hash[0]+1) % 255
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, hash, rs.ProposalBlockParts.Header())
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, hash, rs.ProposalBlockParts.Header(), nil)
 
 	<-timeoutWaitCh
 
@@ -920,7 +911,7 @@ func TestSlashingPrevotes(t *testing.T) {
 	// away and ignore more prevotes (and thus fail to slash!)
 
 	// add the conflicting vote
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header())
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(),nil)
 
 	// XXX: Check for existence of Dupeout info
 }
@@ -942,7 +933,7 @@ func TestSlashingPrecommits(t *testing.T) {
 	<-voteCh // prevote
 
 	// add prevote from cs2
-	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header())
+	signAddVoteToFrom(types.VoteTypePrevote, cs1, cs2, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(), nil)
 
 	<-voteCh // precommit
 
@@ -950,13 +941,13 @@ func TestSlashingPrecommits(t *testing.T) {
 	// add one for a different block should cause us to go into prevote wait
 	hash := rs.ProposalBlock.Hash()
 	hash[0] = byte(hash[0]+1) % 255
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, hash, rs.ProposalBlockParts.Header())
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, hash, rs.ProposalBlockParts.Header(),nil)
 
 	// NOTE: we have to send the vote for different block first so we don't just go into precommit round right
 	// away and ignore more prevotes (and thus fail to slash!)
 
 	// add precommit from cs2
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header())
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, rs.ProposalBlock.Hash(), rs.ProposalBlockParts.Header(),nil)
 
 	// XXX: Check for existence of Dupeout info
 }
@@ -990,15 +981,15 @@ func TestHalt1(t *testing.T) {
 
 	<-voteCh // prevote
 
-	signAddVoteToFromMany(types.VoteTypePrevote, cs1, propBlock.Hash(), propBlockParts.Header(), cs3, cs4)
+	signAddVoteToFromMany(types.VoteTypePrevote, cs1, propBlock.Hash(), propBlockParts.Header(), nil, cs3, cs4)
 	<-voteCh // precommit
 
 	// the proposed block should now be locked and our precommit added
 	validatePrecommit(t, cs1, 0, 0, vss[0], propBlock.Hash(), propBlock.Hash())
 
 	// add precommits from the rest
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, nil, types.PartSetHeader{}) // didnt receive proposal
-	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs3, propBlock.Hash(), propBlockParts.Header())
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs2, nil, types.PartSetHeader{}, nil) // didnt receive proposal
+	signAddVoteToFrom(types.VoteTypePrecommit, cs1, cs3, propBlock.Hash(), propBlockParts.Header(), nil)
 	// we receive this later, but cs3 might receive it earlier and with ours will go to commit!
 	precommit4 := signVote(cs4, types.VoteTypePrecommit, propBlock.Hash(), propBlockParts.Header())
 
@@ -1028,6 +1019,6 @@ func TestHalt1(t *testing.T) {
 	rs = re.(types.EventDataRoundState).RoundState.(*RoundState)
 
 	if rs.Height != 2 {
-		t.Fatal("expected height to increment")
+		panic("expected height to increment")
 	}
 }
diff --git a/consensus/wal_test.go b/consensus/wal_test.go
index 808a5e41..648692e4 100644
--- a/consensus/wal_test.go
+++ b/consensus/wal_test.go
@@ -6,6 +6,8 @@ import (
 	"path"
 	"strings"
 	"testing"
+
+	. "github.com/tendermint/go-common"
 )
 
 var testTxt = `{"time":"2016-01-16T04:42:00.390Z","msg":[1,{"height":28219,"round":0,"step":"RoundStepPrevote"}]}
@@ -18,7 +20,7 @@ var testTxt = `{"time":"2016-01-16T04:42:00.390Z","msg":[1,{"height":28219,"roun
 func TestSeek(t *testing.T) {
 	f, err := ioutil.TempFile(os.TempDir(), "seek_test_")
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 
 	stat, _ := f.Stat()
@@ -26,13 +28,13 @@ func TestSeek(t *testing.T) {
 
 	_, err = f.WriteString(testTxt)
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	f.Close()
 
 	wal, err := NewWAL(path.Join(os.TempDir(), name), config.GetBool("cswal_light"))
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 
 	keyWord := "Precommit"
@@ -43,7 +45,7 @@ func TestSeek(t *testing.T) {
 		return false
 	})
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 
 	// confirm n
@@ -58,18 +60,18 @@ func TestSeek(t *testing.T) {
 	// n is lines from the end.
 	spl = spl[i:]
 	if n != len(spl) {
-		t.Fatalf("Wrong nLines. Got %d, expected %d", n, len(spl))
+		panic(Fmt("Wrong nLines. Got %d, expected %d", n, len(spl)))
 	}
 
 	b, err := ioutil.ReadAll(wal.fp)
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	// first char is a \n
 	spl2 := strings.Split(strings.Trim(string(b), "\n"), "\n")
 	for i, s := range spl {
 		if s != spl2[i] {
-			t.Fatalf("Mismatch. Got %s, expected %s", spl2[i], s)
+			panic(Fmt("Mismatch. Got %s, expected %s", spl2[i], s))
 		}
 	}
 
diff --git a/glide.lock b/glide.lock
index 1cc00875..03693aa4 100644
--- a/glide.lock
+++ b/glide.lock
@@ -54,9 +54,9 @@ imports:
 - name: github.com/tendermint/go-clist
   version: 634527f5b60fd7c71ca811262493df2ad65ee0ca
 - name: github.com/tendermint/go-common
-  version: dcfa46af1341d03b80d32e4901019d1668b978b9
+  version: dee6622bf7f811d3ba8638a3f5ffaf8d679aa9d9
 - name: github.com/tendermint/go-config
-  version: cfcef384d64b94e50909596e39b32ffb3cc20573
+  version: e64b424499acd0eb9856b88e10c0dff41628c0d6
 - name: github.com/tendermint/go-crypto
   version: 41cfb7b677f4e16cdfd22b6ce0946c89919fbc7b
 - name: github.com/tendermint/go-db
@@ -68,7 +68,7 @@ imports:
 - name: github.com/tendermint/go-merkle
   version: 05042c6ab9cad51d12e4cecf717ae68e3b1409a8
 - name: github.com/tendermint/go-p2p
-  version: 5bd7692323ec60d6461678f09b5024a952164151
+  version: 929cf433b9c8e987af5f7f3ca3ce717e1e3eda53
   subpackages:
   - upnp
 - name: github.com/tendermint/go-rpc
@@ -84,7 +84,7 @@ imports:
   subpackages:
   - term
 - name: github.com/tendermint/tmsp
-  version: f41bc5f11969e22b357d94b4247403fd62d40445
+  version: 49a67aee8a7984a68eabe2c45ff6eb0ff51e31f9
   subpackages:
   - client
   - example/dummy
@@ -115,7 +115,7 @@ imports:
   subpackages:
   - unix
 - name: google.golang.org/grpc
-  version: 88aeffff979aa77aa502cb011423d0a08fa12c5a
+  version: daeb9cc0f2607997cce611a1458e71b981ce5986
   subpackages:
   - codes
   - credentials
diff --git a/mempool/mempool.go b/mempool/mempool.go
index 87a185ef..6cd2227c 100644
--- a/mempool/mempool.go
+++ b/mempool/mempool.go
@@ -60,7 +60,7 @@ type Mempool struct {
 	// Keep a cache of already-seen txs.
 	// This reduces the pressure on the proxyApp.
 	cacheMap  map[string]struct{}
-	cacheList *list.List
+	cacheList *list.List // to remove oldest tx when cache gets too big
 }
 
 func NewMempool(config cfg.Config, proxyAppConn proxy.AppConn) *Mempool {
@@ -81,6 +81,7 @@ func NewMempool(config cfg.Config, proxyAppConn proxy.AppConn) *Mempool {
 	return mempool
 }
 
+// consensus must be able to hold lock to safely update
 func (mem *Mempool) Lock() {
 	mem.proxyMtx.Lock()
 }
@@ -89,10 +90,25 @@ func (mem *Mempool) Unlock() {
 	mem.proxyMtx.Unlock()
 }
 
+// Number of transactions in the mempool clist
 func (mem *Mempool) Size() int {
 	return mem.txs.Len()
 }
 
+// Remove all transactions from mempool and cache
+func (mem *Mempool) Flush() {
+	mem.proxyMtx.Lock()
+	defer mem.proxyMtx.Unlock()
+
+	mem.cacheMap = make(map[string]struct{}, cacheSize)
+	mem.cacheList.Init()
+
+	for e := mem.txs.Front(); e != nil; e = e.Next() {
+		mem.txs.Remove(e)
+		e.DetachPrev()
+	}
+}
+
 // Return the first element of mem.txs for peer goroutines to call .NextWait() on.
 // Blocks until txs has elements.
 func (mem *Mempool) TxsFrontWait() *clist.CElement {
@@ -125,6 +141,8 @@ func (mem *Mempool) CheckTx(tx types.Tx, cb func(*tmsp.Response)) (err error) {
 	if mem.cacheList.Len() >= cacheSize {
 		popped := mem.cacheList.Front()
 		poppedTx := popped.Value.(types.Tx)
+		// NOTE: the tx may have already been removed from the map
+		// but deleting a non-existant element is fine
 		delete(mem.cacheMap, string(poppedTx))
 		mem.cacheList.Remove(popped)
 	}
@@ -144,6 +162,13 @@ func (mem *Mempool) CheckTx(tx types.Tx, cb func(*tmsp.Response)) (err error) {
 	return nil
 }
 
+func (mem *Mempool) removeTxFromCacheMap(tx []byte) {
+	mem.proxyMtx.Lock()
+	// NOTE tx not removed from cacheList
+	delete(mem.cacheMap, string(tx))
+	mem.proxyMtx.Unlock()
+}
+
 // TMSP callback function
 func (mem *Mempool) resCb(req *tmsp.Request, res *tmsp.Response) {
 	if mem.recheckCursor == nil {
@@ -165,8 +190,14 @@ func (mem *Mempool) resCbNormal(req *tmsp.Request, res *tmsp.Response) {
 			}
 			mem.txs.PushBack(memTx)
 		} else {
-			log.Info("Bad Transaction", "res", r)
 			// ignore bad transaction
+			log.Info("Bad Transaction", "res", r)
+
+			// remove from cache (it might be good later)
+			// note this is an async callback,
+			// so we need to grab the lock in removeTxFromCacheMap
+			mem.removeTxFromCacheMap(req.GetCheckTx().Tx)
+
 			// TODO: handle other retcodes
 		}
 	default:
@@ -188,6 +219,9 @@ func (mem *Mempool) resCbRecheck(req *tmsp.Request, res *tmsp.Response) {
 			// Tx became invalidated due to newly committed block.
 			mem.txs.Remove(mem.recheckCursor)
 			mem.recheckCursor.DetachPrev()
+
+			// remove from cache (it might be good later)
+			mem.removeTxFromCacheMap(req.GetCheckTx().Tx)
 		}
 		if mem.recheckCursor == mem.recheckEnd {
 			mem.recheckCursor = nil
@@ -270,10 +304,13 @@ func (mem *Mempool) filterTxs(blockTxsMap map[string]struct{}) []types.Tx {
 	goodTxs := make([]types.Tx, 0, mem.txs.Len())
 	for e := mem.txs.Front(); e != nil; e = e.Next() {
 		memTx := e.Value.(*mempoolTx)
+		// Remove the tx if it's alredy in a block.
 		if _, ok := blockTxsMap[string(memTx.tx)]; ok {
-			// Remove the tx since already in block.
+			// remove from clist
 			mem.txs.Remove(e)
 			e.DetachPrev()
+
+			// NOTE: we don't remove committed txs from the cache.
 			continue
 		}
 		// Good tx!
diff --git a/node/node.go b/node/node.go
index 3d2c9196..231b6b65 100644
--- a/node/node.go
+++ b/node/node.go
@@ -177,6 +177,7 @@ func (n *Node) AddListener(l p2p.Listener) {
 func (n *Node) StartRPC() ([]net.Listener, error) {
 	rpccore.SetConfig(n.config)
 
+	rpccore.SetEventSwitch(n.evsw)
 	rpccore.SetBlockStore(n.blockStore)
 	rpccore.SetConsensusState(n.consensusState)
 	rpccore.SetConsensusReactor(n.consensusReactor)
diff --git a/rpc/core/dev.go b/rpc/core/dev.go
index 2b8dfb8f..6ae2014b 100644
--- a/rpc/core/dev.go
+++ b/rpc/core/dev.go
@@ -9,6 +9,11 @@ import (
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 )
 
+func UnsafeFlushMempool() (*ctypes.ResultUnsafeFlushMempool, error) {
+	mempoolReactor.Mempool.Flush()
+	return &ctypes.ResultUnsafeFlushMempool{}, nil
+}
+
 func UnsafeSetConfig(typ, key, value string) (*ctypes.ResultUnsafeSetConfig, error) {
 	switch typ {
 	case "string":
diff --git a/rpc/core/mempool.go b/rpc/core/mempool.go
index b0e5c0c4..bef85c79 100644
--- a/rpc/core/mempool.go
+++ b/rpc/core/mempool.go
@@ -2,14 +2,18 @@ package core
 
 import (
 	"fmt"
+	"time"
+
+	"github.com/tendermint/go-events"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	"github.com/tendermint/tendermint/types"
 	tmsp "github.com/tendermint/tmsp/types"
 )
 
 //-----------------------------------------------------------------------------
+// NOTE: tx should be signed, but this is only checked at the app level (not by Tendermint!)
 
-// NOTE: tx must be signed
+// Returns right away, with no response
 func BroadcastTxAsync(tx types.Tx) (*ctypes.ResultBroadcastTx, error) {
 	err := mempoolReactor.BroadcastTx(tx, nil)
 	if err != nil {
@@ -18,7 +22,7 @@ func BroadcastTxAsync(tx types.Tx) (*ctypes.ResultBroadcastTx, error) {
 	return &ctypes.ResultBroadcastTx{}, nil
 }
 
-// Note: tx must be signed
+// Returns with the response from CheckTx
 func BroadcastTxSync(tx types.Tx) (*ctypes.ResultBroadcastTx, error) {
 	resCh := make(chan *tmsp.Response, 1)
 	err := mempoolReactor.BroadcastTx(tx, func(res *tmsp.Response) {
@@ -36,8 +40,70 @@ func BroadcastTxSync(tx types.Tx) (*ctypes.ResultBroadcastTx, error) {
 	}, nil
 }
 
+// CONTRACT: returns error==nil iff the tx is included in a block.
+//
+// If CheckTx fails, return with the response from CheckTx AND an error.
+// Else, block until the tx is included in a block,
+//	and return the result of AppendTx (with no error).
+// Even if AppendTx fails, so long as the tx is included in a block this function
+//	will not return an error - it is the caller's responsibility to check res.Code.
+// The function times out after five minutes and returns the result of CheckTx and an error.
+// TODO: smarter timeout logic or someway to cancel (tx not getting committed is a sign of a larger problem!)
+func BroadcastTxCommit(tx types.Tx) (*ctypes.ResultBroadcastTx, error) {
+
+	// subscribe to tx being committed in block
+	appendTxResCh := make(chan *tmsp.Response, 1)
+	eventSwitch.AddListenerForEvent("rpc", types.EventStringTx(tx), func(data events.EventData) {
+		appendTxResCh <- data.(*tmsp.Response)
+	})
+
+	// broadcast the tx and register checktx callback
+	checkTxResCh := make(chan *tmsp.Response, 1)
+	err := mempoolReactor.BroadcastTx(tx, func(res *tmsp.Response) {
+		checkTxResCh <- res
+	})
+	if err != nil {
+		return nil, fmt.Errorf("Error broadcasting transaction: %v", err)
+	}
+	checkTxRes := <-checkTxResCh
+	checkTxR := checkTxRes.GetCheckTx()
+	if r := checkTxR; r.Code != tmsp.CodeType_OK {
+		// CheckTx failed!
+		return &ctypes.ResultBroadcastTx{
+			Code: r.Code,
+			Data: r.Data,
+			Log:  r.Log,
+		}, fmt.Errorf("Check tx failed with non-zero code: %s. Data: %X; Log: %s", r.Code.String(), r.Data, r.Log)
+	}
+
+	// Wait for the tx to be included in a block,
+	// timeout after something reasonable.
+	timer := time.NewTimer(60 * 5 * time.Second)
+	select {
+	case appendTxRes := <-appendTxResCh:
+		// The tx was included in a block.
+		// NOTE we don't return an error regardless of the AppendTx code;
+		// 	clients must check this to see if they need to send a new tx!
+		r := appendTxRes.GetAppendTx()
+		return &ctypes.ResultBroadcastTx{
+			Code: r.Code,
+			Data: r.Data,
+			Log:  r.Log,
+		}, nil
+	case <-timer.C:
+		r := checkTxR
+		return &ctypes.ResultBroadcastTx{
+			Code: r.Code,
+			Data: r.Data,
+			Log:  r.Log,
+		}, fmt.Errorf("Timed out waiting for transaction to be included in a block")
+	}
+
+	panic("Should never happen!")
+}
+
 func UnconfirmedTxs() (*ctypes.ResultUnconfirmedTxs, error) {
-	txs := mempoolReactor.Mempool.Reap(0)
+	txs := mempoolReactor.Mempool.Reap(-1)
 	return &ctypes.ResultUnconfirmedTxs{len(txs), txs}, nil
 }
 
diff --git a/rpc/core/pipe.go b/rpc/core/pipe.go
index de196e81..464f7fda 100644
--- a/rpc/core/pipe.go
+++ b/rpc/core/pipe.go
@@ -4,12 +4,14 @@ import (
 	cfg "github.com/tendermint/go-config"
 	"github.com/tendermint/go-p2p"
 
+	"github.com/tendermint/go-events"
 	bc "github.com/tendermint/tendermint/blockchain"
 	"github.com/tendermint/tendermint/consensus"
 	mempl "github.com/tendermint/tendermint/mempool"
 	"github.com/tendermint/tendermint/types"
 )
 
+var eventSwitch *events.EventSwitch
 var blockStore *bc.BlockStore
 var consensusState *consensus.ConsensusState
 var consensusReactor *consensus.ConsensusReactor
@@ -24,6 +26,10 @@ func SetConfig(c cfg.Config) {
 	config = c
 }
 
+func SetEventSwitch(evsw *events.EventSwitch) {
+	eventSwitch = evsw
+}
+
 func SetBlockStore(bs *bc.BlockStore) {
 	blockStore = bs
 }
diff --git a/rpc/core/routes.go b/rpc/core/routes.go
index 585a18cd..78a0b618 100644
--- a/rpc/core/routes.go
+++ b/rpc/core/routes.go
@@ -19,11 +19,13 @@ var Routes = map[string]*rpc.RPCFunc{
 	"block":                rpc.NewRPCFunc(BlockResult, "height"),
 	"validators":           rpc.NewRPCFunc(ValidatorsResult, ""),
 	"dump_consensus_state": rpc.NewRPCFunc(DumpConsensusStateResult, ""),
+	"broadcast_tx_commit":  rpc.NewRPCFunc(BroadcastTxCommitResult, "tx"),
 	"broadcast_tx_sync":    rpc.NewRPCFunc(BroadcastTxSyncResult, "tx"),
 	"broadcast_tx_async":   rpc.NewRPCFunc(BroadcastTxAsyncResult, "tx"),
 	"unconfirmed_txs":      rpc.NewRPCFunc(UnconfirmedTxsResult, ""),
 	"num_unconfirmed_txs":  rpc.NewRPCFunc(NumUnconfirmedTxsResult, ""),
 
+	"unsafe_flush_mempool":      rpc.NewRPCFunc(UnsafeFlushMempool, ""),
 	"unsafe_set_config":         rpc.NewRPCFunc(UnsafeSetConfigResult, "type,key,value"),
 	"unsafe_start_cpu_profiler": rpc.NewRPCFunc(UnsafeStartCPUProfilerResult, "filename"),
 	"unsafe_stop_cpu_profiler":  rpc.NewRPCFunc(UnsafeStopCPUProfilerResult, ""),
@@ -126,6 +128,14 @@ func NumUnconfirmedTxsResult() (ctypes.TMResult, error) {
 	}
 }
 
+func BroadcastTxCommitResult(tx []byte) (ctypes.TMResult, error) {
+	if r, err := BroadcastTxCommit(tx); err != nil {
+		return nil, err
+	} else {
+		return r, nil
+	}
+}
+
 func BroadcastTxSyncResult(tx []byte) (ctypes.TMResult, error) {
 	if r, err := BroadcastTxSync(tx); err != nil {
 		return nil, err
@@ -142,6 +152,14 @@ func BroadcastTxAsyncResult(tx []byte) (ctypes.TMResult, error) {
 	}
 }
 
+func UnsafeFlushMempoolResult() (ctypes.TMResult, error) {
+	if r, err := UnsafeFlushMempool(); err != nil {
+		return nil, err
+	} else {
+		return r, nil
+	}
+}
+
 func UnsafeSetConfigResult(typ, key, value string) (ctypes.TMResult, error) {
 	if r, err := UnsafeSetConfig(typ, key, value); err != nil {
 		return nil, err
diff --git a/rpc/core/types/responses.go b/rpc/core/types/responses.go
index d08892e8..c1eebb6e 100644
--- a/rpc/core/types/responses.go
+++ b/rpc/core/types/responses.go
@@ -68,6 +68,8 @@ type ResultUnconfirmedTxs struct {
 	Txs []types.Tx `json:"txs"`
 }
 
+type ResultUnsafeFlushMempool struct{}
+
 type ResultUnsafeSetConfig struct{}
 
 type ResultUnsafeProfile struct{}
@@ -115,6 +117,7 @@ const (
 	ResultTypeUnsafeStartCPUProfiler = byte(0xa1)
 	ResultTypeUnsafeStopCPUProfiler  = byte(0xa2)
 	ResultTypeUnsafeWriteHeapProfile = byte(0xa3)
+	ResultTypeUnsafeFlushMempool     = byte(0xa4)
 )
 
 type TMResult interface {
@@ -141,4 +144,5 @@ var _ = wire.RegisterInterface(
 	wire.ConcreteType{&ResultUnsafeProfile{}, ResultTypeUnsafeStartCPUProfiler},
 	wire.ConcreteType{&ResultUnsafeProfile{}, ResultTypeUnsafeStopCPUProfiler},
 	wire.ConcreteType{&ResultUnsafeProfile{}, ResultTypeUnsafeWriteHeapProfile},
+	wire.ConcreteType{&ResultUnsafeFlushMempool{}, ResultTypeUnsafeFlushMempool},
 )
diff --git a/rpc/test/client_test.go b/rpc/test/client_test.go
index a5b243be..47d2ead1 100644
--- a/rpc/test/client_test.go
+++ b/rpc/test/client_test.go
@@ -1,11 +1,15 @@
 package rpctest
 
 import (
+	"bytes"
+	"crypto/rand"
 	"fmt"
 	"testing"
 
+	. "github.com/tendermint/go-common"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	"github.com/tendermint/tendermint/types"
+	tmsp "github.com/tendermint/tmsp/types"
 )
 
 //--------------------------------------------------------------------------------
@@ -19,7 +23,7 @@ func TestURIStatus(t *testing.T) {
 	tmResult := new(ctypes.TMResult)
 	_, err := clientURI.Call("status", map[string]interface{}{}, tmResult)
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	testStatus(t, tmResult)
 }
@@ -28,7 +32,7 @@ func TestJSONStatus(t *testing.T) {
 	tmResult := new(ctypes.TMResult)
 	_, err := clientJSON.Call("status", []interface{}{}, tmResult)
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	testStatus(t, tmResult)
 }
@@ -37,38 +41,102 @@ func testStatus(t *testing.T, statusI interface{}) {
 	tmRes := statusI.(*ctypes.TMResult)
 	status := (*tmRes).(*ctypes.ResultStatus)
 	if status.NodeInfo.Network != chainID {
-		t.Fatal(fmt.Errorf("ChainID mismatch: got %s expected %s",
+		panic(Fmt("ChainID mismatch: got %s expected %s",
 			status.NodeInfo.Network, chainID))
 	}
 }
 
-// TODO
-/*
-func testBroadcastTx(t *testing.T, typ string) {
-	amt := int64(100)
-	toAddr := user[1].Address
-	tx := makeDefaultSendTxSigned(t, typ, toAddr, amt)
-	receipt := broadcastTx(t, typ, tx)
-	if receipt.CreatesContract > 0 {
-		t.Fatal("This tx does not create a contract")
+//--------------------------------------------------------------------------------
+// broadcast tx sync
+
+func testTx() []byte {
+	buf := make([]byte, 16)
+	_, err := rand.Read(buf)
+	if err != nil {
+		panic(err)
 	}
-	if len(receipt.TxHash) == 0 {
-		t.Fatal("Failed to compute tx hash")
+	return buf
+}
+
+func TestURIBroadcastTxSync(t *testing.T) {
+	config.Set("block_size", 0)
+	defer config.Set("block_size", -1)
+	tmResult := new(ctypes.TMResult)
+	tx := testTx()
+	_, err := clientURI.Call("broadcast_tx_sync", map[string]interface{}{"tx": tx}, tmResult)
+	if err != nil {
+		panic(err)
 	}
-	pool := node.MempoolReactor().Mempool
-	txs := pool.GetProposalTxs()
-	if len(txs) != mempoolCount {
-		t.Fatalf("The mem pool has %d txs. Expected %d", len(txs), mempoolCount)
+	testBroadcastTxSync(t, tmResult, tx)
+}
+
+func TestJSONBroadcastTxSync(t *testing.T) {
+	config.Set("block_size", 0)
+	defer config.Set("block_size", -1)
+	tmResult := new(ctypes.TMResult)
+	tx := testTx()
+	_, err := clientJSON.Call("broadcast_tx_sync", []interface{}{tx}, tmResult)
+	if err != nil {
+		panic(err)
 	}
-	tx2 := txs[mempoolCount-1].(*types.SendTx)
-	n, err := new(int64), new(error)
-	buf1, buf2 := new(bytes.Buffer), new(bytes.Buffer)
-	tx.WriteSignBytes(chainID, buf1, n, err)
-	tx2.WriteSignBytes(chainID, buf2, n, err)
-	if bytes.Compare(buf1.Bytes(), buf2.Bytes()) != 0 {
-		t.Fatal("inconsistent hashes for mempool tx and sent tx")
+	testBroadcastTxSync(t, tmResult, tx)
+}
+
+func testBroadcastTxSync(t *testing.T, resI interface{}, tx []byte) {
+	tmRes := resI.(*ctypes.TMResult)
+	res := (*tmRes).(*ctypes.ResultBroadcastTx)
+	if res.Code != tmsp.CodeType_OK {
+		panic(Fmt("BroadcastTxSync got non-zero exit code: %v. %X; %s", res.Code, res.Data, res.Log))
 	}
-}*/
+	mem := node.MempoolReactor().Mempool
+	if mem.Size() != 1 {
+		panic(Fmt("Mempool size should have been 1. Got %d", mem.Size()))
+	}
+
+	txs := mem.Reap(1)
+	if !bytes.Equal(txs[0], tx) {
+		panic(Fmt("Tx in mempool does not match test tx. Got %X, expected %X", txs[0], testTx))
+	}
+
+	mem.Flush()
+}
+
+//--------------------------------------------------------------------------------
+// broadcast tx commit
+
+func TestURIBroadcastTxCommit(t *testing.T) {
+	tmResult := new(ctypes.TMResult)
+	tx := testTx()
+	_, err := clientURI.Call("broadcast_tx_commit", map[string]interface{}{"tx": tx}, tmResult)
+	if err != nil {
+		panic(err)
+	}
+	testBroadcastTxCommit(t, tmResult, tx)
+}
+
+func TestJSONBroadcastTxCommit(t *testing.T) {
+	tmResult := new(ctypes.TMResult)
+	tx := testTx()
+	_, err := clientJSON.Call("broadcast_tx_commit", []interface{}{tx}, tmResult)
+	if err != nil {
+		panic(err)
+	}
+	testBroadcastTxCommit(t, tmResult, tx)
+}
+
+func testBroadcastTxCommit(t *testing.T, resI interface{}, tx []byte) {
+	tmRes := resI.(*ctypes.TMResult)
+	res := (*tmRes).(*ctypes.ResultBroadcastTx)
+	if res.Code != tmsp.CodeType_OK {
+		panic(Fmt("BroadcastTxCommit got non-zero exit code: %v. %X; %s", res.Code, res.Data, res.Log))
+	}
+	mem := node.MempoolReactor().Mempool
+	if mem.Size() != 0 {
+		panic(Fmt("Mempool size should have been 0. Got %d", mem.Size()))
+	}
+
+	// TODO: find tx in block
+}
 
 //--------------------------------------------------------------------------------
 // Test the websocket service
@@ -179,7 +247,7 @@ func TestURIUnsafeSetConfig(t *testing.T) {
 			"value": testCase[2],
 		}, tmResult)
 		if err != nil {
-			t.Fatal(err)
+			panic(err)
 		}
 	}
 	testUnsafeSetConfig(t)
@@ -190,7 +258,7 @@ func TestJSONUnsafeSetConfig(t *testing.T) {
 		tmResult := new(ctypes.TMResult)
 		_, err := clientJSON.Call("unsafe_set_config", []interface{}{testCase[0], testCase[1], testCase[2]}, tmResult)
 		if err != nil {
-			t.Fatal(err)
+			panic(err)
 		}
 	}
 	testUnsafeSetConfig(t)
@@ -199,16 +267,16 @@ func TestJSONUnsafeSetConfig(t *testing.T) {
 func testUnsafeSetConfig(t *testing.T) {
 	s := config.GetString("key1")
 	if s != stringVal {
-		t.Fatalf("got %v, expected %v", s, stringVal)
+		panic(Fmt("got %v, expected %v", s, stringVal))
 	}
 
 	i := config.GetInt("key2")
 	if i != intVal {
-		t.Fatalf("got %v, expected %v", i, intVal)
+		panic(Fmt("got %v, expected %v", i, intVal))
 	}
 
 	b := config.GetBool("key3")
 	if b != boolVal {
-		t.Fatalf("got %v, expected %v", b, boolVal)
+		panic(Fmt("got %v, expected %v", b, boolVal))
 	}
 }
diff --git a/rpc/test/helpers.go b/rpc/test/helpers.go
index c209324b..59709ada 100644
--- a/rpc/test/helpers.go
+++ b/rpc/test/helpers.go
@@ -20,7 +20,6 @@ import (
 var (
 	config            cfg.Config
 	node              *nm.Node
-	mempoolCount      = 0
 	chainID           string
 	rpcAddr           string
 	requestAddr       string
@@ -76,7 +75,7 @@ func newNode(ready chan struct{}) {
 func newWSClient(t *testing.T) *client.WSClient {
 	wsc := client.NewWSClient(websocketAddr, websocketEndpoint)
 	if _, err := wsc.Start(); err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 	return wsc
 }
@@ -84,14 +83,14 @@ func newWSClient(t *testing.T) *client.WSClient {
 // subscribe to an event
 func subscribe(t *testing.T, wsc *client.WSClient, eventid string) {
 	if err := wsc.Subscribe(eventid); err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 }
 
 // unsubscribe from an event
 func unsubscribe(t *testing.T, wsc *client.WSClient, eventid string) {
 	if err := wsc.Unsubscribe(eventid); err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
 }
 
@@ -138,7 +137,7 @@ func waitForEvent(t *testing.T, wsc *client.WSClient, eventid string, dieOnTimeo
 	case <-timeout.C:
 		if dieOnTimeout {
 			wsc.Stop()
-			t.Fatalf("%s event was not received in time", eventid)
+			panic(Fmt("%s event was not received in time", eventid))
 		}
 		// else that's great, we didn't hear the event
 		// and we shouldn't have
@@ -147,14 +146,13 @@ func waitForEvent(t *testing.T, wsc *client.WSClient, eventid string, dieOnTimeo
 			// message was received and expected
 			// run the check
 			if err := check(eventid, eventData); err != nil {
-				t.Fatal(err) // Show the stack trace.
+				panic(err) // Show the stack trace.
 			}
 		} else {
 			wsc.Stop()
-			t.Fatalf("%s event was not expected", eventid)
+			panic(Fmt("%s event was not expected", eventid))
 		}
 	case err := <-errCh:
-		t.Fatal(err)
 		panic(err) // Show the stack trace.
 
 	}
diff --git a/state/execution.go b/state/execution.go
index 230bceb2..1acd0493 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -18,7 +18,7 @@ func (s *State) ValidateBlock(block *types.Block) error {
 
 // Execute the block to mutate State.
 // Validates block and then executes Data.Txs in the block.
-func (s *State) ExecBlock(evsw *events.EventSwitch, proxyAppConn proxy.AppConn, block *types.Block, blockPartsHeader types.PartSetHeader) error {
+func (s *State) ExecBlock(eventCache events.Fireable, proxyAppConn proxy.AppConn, block *types.Block, blockPartsHeader types.PartSetHeader) error {
 
 	// Validate the block.
 	err := s.validateBlock(block)
@@ -34,7 +34,7 @@ func (s *State) ExecBlock(evsw *events.EventSwitch, proxyAppConn proxy.AppConn,
 	nextValSet := valSet.Copy()
 
 	// Execute the block txs
-	err = s.execBlockOnProxyApp(evsw, proxyAppConn, block)
+	err = s.execBlockOnProxyApp(eventCache, proxyAppConn, block)
 	if err != nil {
 		// There was some error in proxyApp
 		// TODO Report error and wait for proxyApp to be available.
@@ -55,7 +55,7 @@ func (s *State) ExecBlock(evsw *events.EventSwitch, proxyAppConn proxy.AppConn,
 
 // Executes block's transactions on proxyAppConn.
 // TODO: Generate a bitmap or otherwise store tx validity in state.
-func (s *State) execBlockOnProxyApp(evsw *events.EventSwitch, proxyAppConn proxy.AppConn, block *types.Block) error {
+func (s *State) execBlockOnProxyApp(eventCache events.Fireable, proxyAppConn proxy.AppConn, block *types.Block) error {
 
 	var validTxs, invalidTxs = 0, 0
 
@@ -73,6 +73,9 @@ func (s *State) execBlockOnProxyApp(evsw *events.EventSwitch, proxyAppConn proxy
 				log.Debug("Invalid tx", "code", r.AppendTx.Code, "log", r.AppendTx.Log)
 				invalidTxs += 1
 			}
+			// NOTE: if we count we can access the tx from the block instead of
+			// pulling it from the req
+			eventCache.FireEvent(types.EventStringTx(req.GetAppendTx().Tx), res)
 		}
 	}
 	proxyAppConn.SetResponseCallback(proxyCb)
diff --git a/test/rpc/clean.sh b/test/rpc/clean.sh
new file mode 100644
index 00000000..1b34033f
--- /dev/null
+++ b/test/rpc/clean.sh
@@ -0,0 +1,3 @@
+killall tendermint
+killall dummy
+killall counter
diff --git a/test/rpc/counter_test.sh b/test/rpc/counter_test.sh
new file mode 100644
index 00000000..809a2212
--- /dev/null
+++ b/test/rpc/counter_test.sh
@@ -0,0 +1,69 @@
+#! /bin/bash
+
+#####################
+# counter over socket
+#####################
+TESTNAME=$1
+
+# Send some txs
+
+function sendTx() {
+	TX=$1
+	RESPONSE=`curl -s localhost:46657/broadcast_tx_commit?tx=\"$TX\"`
+	CODE=`echo $RESPONSE | jq .result[1].code`
+	ERROR=`echo $RESPONSE | jq .error`
+	ERROR=$(echo "$ERROR" | tr -d '"') # remove surrounding quotes
+}
+
+# 0 should pass once and get in block, with no error
+TX=00
+sendTx $TX
+if [[ $CODE != 0 ]]; then
+	echo "Got non-zero exit code for $TX. $RESPONSE"
+	exit 1
+fi
+if [[ "$ERROR" != "" ]]; then
+	echo "Unexpected error. Tx $TX should have been included in a block. $ERROR"
+	exit 1
+fi
+
+
+
+# second time should get rejected by the mempool (return error and non-zero code)
+sendTx $TX
+if [[ $CODE == 0 ]]; then
+	echo "Got zero exit code for $TX. Expected tx to be rejected by mempool. $RESPONSE"
+	exit 1
+fi
+if [[ "$ERROR" == "" ]]; then
+	echo "Expected to get an error - tx $TX should have been rejected from mempool"
+	echo "$RESPONSE"
+	exit 1
+fi
+
+
+# now, TX=01 should pass, with no error
+TX=01
+sendTx $TX
+if [[ $CODE != 0 ]]; then
+	echo "Got non-zero exit code for $TX. $RESPONSE"
+	exit 1
+fi
+if [[ "$ERROR" != "" ]]; then
+	echo "Unexpected error. Tx $TX should have been accepted in block. $ERROR"
+	exit 1
+fi
+
+# now, TX=03 should get in a block (passes CheckTx, no error), but is invalid
+TX=03
+sendTx $TX
+if [[ $CODE == 0 ]]; then
+	echo "Got zero exit code for $TX. Should have been bad nonce. $RESPONSE"
+	exit 1
+fi
+if [[ "$ERROR" != "" ]]; then
+	echo "Unexpected error. Tx $TX should have been included in a block. $ERROR"
+	exit 1
+fi
+
+echo "Passed Test: $TESTNAME"
diff --git a/test/rpc/dummy_test.sh b/test/rpc/dummy_test.sh
new file mode 100644
index 00000000..9410c88d
--- /dev/null
+++ b/test/rpc/dummy_test.sh
@@ -0,0 +1,34 @@
+#! /bin/bash
+
+function toHex() {
+	echo -n $1 | hexdump -ve '1/1 "%.2X"'
+}
+
+#####################
+# dummy with curl
+#####################
+TESTNAME=$1
+
+# store key value pair
+KEY="abcd"
+VALUE="dcba"
+curl localhost:46657/broadcast_tx_commit?tx=\"$(toHex $KEY=$VALUE)\"
+echo ""
+
+# we should be able to look up the key
+RESPONSE=`tmsp-cli query $KEY`
+A=`echo $RESPONSE | grep exists=true`
+if [[ $? != 0 ]]; then
+	echo "Failed to find 'exists=true' for $KEY. Response:"
+	echo "$RESPONSE"
+fi
+
+# we should not be able to look up the value
+RESPONSE=`tmsp-cli query $VALUE`
+A=`echo $RESPONSE | grep exists=true`
+if [[ $? == 0 ]]; then
+	echo "Found 'exists=true' for $VALUE when we should not have. Response:"
+	echo "$RESPONSE"
+fi
+
+echo "Passed Test: $TESTNAME"
diff --git a/test/rpc/test.sh b/test/rpc/test.sh
new file mode 100644
index 00000000..f31b19c5
--- /dev/null
+++ b/test/rpc/test.sh
@@ -0,0 +1,57 @@
+#! /bin/bash
+set -e
+
+#- dummy over socket, curl
+#- counter over socket, curl
+#- counter over grpc, curl
+#- counter over grpc, grpc
+
+# TODO: install everything
+
+function dummy_over_socket(){
+	dummy > /dev/null &
+	tendermint node > tendermint.log &
+	sleep 3
+
+	bash dummy_test.sh "Dummy over Socket"
+
+	killall dummy tendermint
+}
+
+
+function counter_over_socket() {
+	counter --serial > /dev/null &
+	tendermint node > tendermint.log &
+	sleep 3
+
+	bash counter_test.sh "Counter over Socket"
+
+	killall counter tendermint
+}
+
+function counter_over_grpc() {
+	counter --serial --tmsp grpc > /dev/null &
+	tendermint node --tmsp grpc > tendermint.log &
+	sleep 3
+
+	bash counter_test.sh "Counter over GRPC"
+
+	killall counter tendermint
+}
+
+case "$1" in 
+	"dummy_over_socket")
+		dummy_over_socket
+		;;
+	"counter_over_socket")
+		counter_over_socket
+		;;
+	"counter_over_grpc")
+		counter_over_grpc
+		;;
+	*)
+		dummy_over_socket
+		counter_over_socket
+		counter_over_grpc
+esac
+
diff --git a/types/events.go b/types/events.go
index 3328911c..68313ff2 100644
--- a/types/events.go
+++ b/types/events.go
@@ -2,6 +2,7 @@ package types
 
 import (
 	// for registering TMEventData as events.EventData
+	. "github.com/tendermint/go-common"
 	"github.com/tendermint/go-events"
 	"github.com/tendermint/go-wire"
 )
@@ -14,6 +15,7 @@ func EventStringUnbond() string  { return "Unbond" }
 func EventStringRebond() string  { return "Rebond" }
 func EventStringDupeout() string { return "Dupeout" }
 func EventStringFork() string    { return "Fork" }
+func EventStringTx(tx Tx) string { return Fmt("Tx:%X", tx.Hash()) }
 
 func EventStringNewBlock() string         { return "NewBlock" }
 func EventStringNewBlockHeader() string   { return "NewBlockHeader" }
diff --git a/types/tx.go b/types/tx.go
index 60699d53..a67206d4 100644
--- a/types/tx.go
+++ b/types/tx.go
@@ -6,6 +6,14 @@ import (
 
 type Tx []byte
 
+// NOTE: this is the hash of the go-wire encoded Tx.
+// Tx has no types at this level, so just length-prefixed.
+// Alternatively, it may make sense to add types here and let
+// []byte be type 0x1 so we can have versioned txs if need be in the future.
+func (tx Tx) Hash() []byte {
+	return merkle.SimpleHashFromBinary(tx)
+}
+
 type Txs []Tx
 
 func (txs Txs) Hash() []byte {
@@ -15,7 +23,7 @@ func (txs Txs) Hash() []byte {
 	case 0:
 		return nil
 	case 1:
-		return merkle.SimpleHashFromBinary(txs[0])
+		return txs[0].Hash()
 	default:
 		left := Txs(txs[:(len(txs)+1)/2]).Hash()
 		right := Txs(txs[(len(txs)+1)/2:]).Hash()