diff --git a/client/commands/seeds/export.go b/client/commands/commits/export.go
similarity index 55%
rename from client/commands/seeds/export.go
rename to client/commands/commits/export.go
index ec381246bd..c27826fa76 100644
--- a/client/commands/seeds/export.go
+++ b/client/commands/commits/export.go
@@ -1,30 +1,32 @@
-package seeds
+package commits
 
 import (
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
+	"github.com/tendermint/light-client/certifiers/files"
+
 	"github.com/cosmos/cosmos-sdk/client/commands"
 )
 
 var exportCmd = &cobra.Command{
 	Use:   "export <file>",
-	Short: "Export selected seeds to given file",
-	Long: `Exports the most recent seed to a binary file.
+	Short: "Export selected commits to given file",
+	Long: `Exports the most recent commit to a binary file.
 If desired, you can select by an older height or validator hash.
 `,
-	RunE:         commands.RequireInit(exportSeed),
+	RunE:         commands.RequireInit(exportCommit),
 	SilenceUsage: true,
 }
 
 func init() {
-	exportCmd.Flags().Int(heightFlag, 0, "Show the seed with closest height to this")
-	exportCmd.Flags().String(hashFlag, "", "Show the seed matching the validator hash")
+	exportCmd.Flags().Int(heightFlag, 0, "Show the commit with closest height to this")
+	exportCmd.Flags().String(hashFlag, "", "Show the commit matching the validator hash")
 	RootCmd.AddCommand(exportCmd)
 }
 
-func exportSeed(cmd *cobra.Command, args []string) error {
+func exportCommit(cmd *cobra.Command, args []string) error {
 	if len(args) != 1 || len(args[0]) == 0 {
 		return errors.New("You must provide a filepath to output")
 	}
@@ -34,11 +36,11 @@ func exportSeed(cmd *cobra.Command, args []string) error {
 	trust, _ := commands.GetProviders()
 	h := viper.GetInt(heightFlag)
 	hash := viper.GetString(hashFlag)
-	seed, err := loadSeed(trust, h, hash, "")
+	fc, err := loadCommit(trust, h, hash, "")
 	if err != nil {
 		return err
 	}
 
 	// now get the output file and write it
-	return seed.WriteJSON(path)
+	return files.SaveFullCommitJSON(fc, path)
 }
diff --git a/client/commands/seeds/import.go b/client/commands/commits/import.go
similarity index 57%
rename from client/commands/seeds/import.go
rename to client/commands/commits/import.go
index d231f4c3b5..936d25b063 100644
--- a/client/commands/seeds/import.go
+++ b/client/commands/commits/import.go
@@ -1,4 +1,4 @@
-package seeds
+package commits
 
 import (
 	"fmt"
@@ -7,7 +7,7 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
-	"github.com/tendermint/light-client/certifiers"
+	"github.com/tendermint/light-client/certifiers/files"
 
 	"github.com/cosmos/cosmos-sdk/client/commands"
 )
@@ -18,9 +18,9 @@ const (
 
 var importCmd = &cobra.Command{
 	Use:          "import <file>",
-	Short:        "Imports a new seed from the given file",
-	Long:         `Validate this file and update to the given seed if secure.`,
-	RunE:         commands.RequireInit(importSeed),
+	Short:        "Imports a new commit from the given file",
+	Long:         `Validate this file and update to the given commit if secure.`,
+	RunE:         commands.RequireInit(importCommit),
 	SilenceUsage: true,
 }
 
@@ -29,7 +29,7 @@ func init() {
 	RootCmd.AddCommand(importCmd)
 }
 
-func importSeed(cmd *cobra.Command, args []string) error {
+func importCommit(cmd *cobra.Command, args []string) error {
 	if len(args) != 1 || len(args[0]) == 0 {
 		return errors.New("You must provide an input file")
 	}
@@ -42,18 +42,18 @@ func importSeed(cmd *cobra.Command, args []string) error {
 
 	// parse the input file
 	path := args[0]
-	seed, err := certifiers.LoadSeedJSON(path)
+	fc, err := files.LoadFullCommitJSON(path)
 	if err != nil {
 		return err
 	}
 
 	// just do simple checks in --dry-run
 	if viper.GetBool(dryFlag) {
-		fmt.Printf("Testing seed %d/%X\n", seed.Height(), seed.Hash())
-		err = seed.ValidateBasic(cert.ChainID())
+		fmt.Printf("Testing commit %d/%X\n", fc.Height(), fc.ValidatorsHash())
+		err = fc.ValidateBasic(cert.ChainID())
 	} else {
-		fmt.Printf("Importing seed %d/%X\n", seed.Height(), seed.Hash())
-		err = cert.Update(seed.Checkpoint, seed.Validators)
+		fmt.Printf("Importing commit %d/%X\n", fc.Height(), fc.ValidatorsHash())
+		err = cert.Update(fc)
 	}
 	return err
 }
diff --git a/client/commands/seeds/root.go b/client/commands/commits/root.go
similarity index 52%
rename from client/commands/seeds/root.go
rename to client/commands/commits/root.go
index b4fc9d66f6..513d86873e 100644
--- a/client/commands/seeds/root.go
+++ b/client/commands/commits/root.go
@@ -1,15 +1,15 @@
-package seeds
+package commits
 
 import "github.com/spf13/cobra"
 
 // RootCmd represents the base command when called without any subcommands
 var RootCmd = &cobra.Command{
-	Use:   "seeds",
-	Short: "Verify seeds from your local store",
-	Long: `Seeds allows you to inspect and update the validator set for the chain.
+	Use:   "commits",
+	Short: "Verify commits from your local store",
+	Long: `Commits allows you to inspect and update the validator set for the chain.
 
 Since all security in a PoS system is based on having the correct validator
-set, it is important to inspect the seeds to maintain the security, which
+set, it is important to inspect the commits to maintain the security, which
 is used to verify all header and merkle proofs.
 `,
 }
diff --git a/client/commands/seeds/show.go b/client/commands/commits/show.go
similarity index 51%
rename from client/commands/seeds/show.go
rename to client/commands/commits/show.go
index 852cb0b82c..e9cc6ed28f 100644
--- a/client/commands/seeds/show.go
+++ b/client/commands/commits/show.go
@@ -1,4 +1,4 @@
-package seeds
+package commits
 
 import (
 	"encoding/hex"
@@ -9,6 +9,7 @@ import (
 	"github.com/spf13/viper"
 
 	"github.com/tendermint/light-client/certifiers"
+	"github.com/tendermint/light-client/certifiers/files"
 
 	"github.com/cosmos/cosmos-sdk/client/commands"
 )
@@ -21,53 +22,53 @@ const (
 
 var showCmd = &cobra.Command{
 	Use:   "show",
-	Short: "Show the details of one selected seed",
+	Short: "Show the details of one selected commit",
 	Long: `Shows the most recent downloaded key by default.
 If desired, you can select by height, validator hash, or a file.
 `,
-	RunE:         commands.RequireInit(showSeed),
+	RunE:         commands.RequireInit(showCommit),
 	SilenceUsage: true,
 }
 
 func init() {
-	showCmd.Flags().Int(heightFlag, 0, "Show the seed with closest height to this")
-	showCmd.Flags().String(hashFlag, "", "Show the seed matching the validator hash")
-	showCmd.Flags().String(fileFlag, "", "Show the seed stored in the given file")
+	showCmd.Flags().Int(heightFlag, 0, "Show the commit with closest height to this")
+	showCmd.Flags().String(hashFlag, "", "Show the commit matching the validator hash")
+	showCmd.Flags().String(fileFlag, "", "Show the commit stored in the given file")
 	RootCmd.AddCommand(showCmd)
 }
 
-func loadSeed(p certifiers.Provider, h int, hash, file string) (seed certifiers.Seed, err error) {
-	// load the seed from the proper place
+func loadCommit(p certifiers.Provider, h int, hash, file string) (fc certifiers.FullCommit, err error) {
+	// load the commit from the proper place
 	if h != 0 {
-		seed, err = p.GetByHeight(h)
+		fc, err = p.GetByHeight(h)
 	} else if hash != "" {
 		var vhash []byte
 		vhash, err = hex.DecodeString(hash)
 		if err == nil {
-			seed, err = p.GetByHash(vhash)
+			fc, err = p.GetByHash(vhash)
 		}
 	} else if file != "" {
-		seed, err = certifiers.LoadSeedJSON(file)
+		fc, err = files.LoadFullCommitJSON(file)
 	} else {
-		// default is latest seed
-		seed, err = certifiers.LatestSeed(p)
+		// default is latest commit
+		fc, err = p.LatestCommit()
 	}
 	return
 }
 
-func showSeed(cmd *cobra.Command, args []string) error {
+func showCommit(cmd *cobra.Command, args []string) error {
 	trust, _ := commands.GetProviders()
 
 	h := viper.GetInt(heightFlag)
 	hash := viper.GetString(hashFlag)
 	file := viper.GetString(fileFlag)
-	seed, err := loadSeed(trust, h, hash, file)
+	fc, err := loadCommit(trust, h, hash, file)
 	if err != nil {
 		return err
 	}
 
 	// now render it!
-	data, err := json.MarshalIndent(seed, "", "  ")
+	data, err := json.MarshalIndent(fc, "", "  ")
 	fmt.Println(string(data))
 	return err
 }
diff --git a/client/commands/seeds/update.go b/client/commands/commits/update.go
similarity index 62%
rename from client/commands/seeds/update.go
rename to client/commands/commits/update.go
index df2a962108..c42144b61b 100644
--- a/client/commands/seeds/update.go
+++ b/client/commands/commits/update.go
@@ -1,4 +1,4 @@
-package seeds
+package commits
 
 import (
 	"fmt"
@@ -13,8 +13,8 @@ import (
 
 var updateCmd = &cobra.Command{
 	Use:          "update",
-	Short:        "Update seed to current height if possible",
-	RunE:         commands.RequireInit(updateSeed),
+	Short:        "Update commit to current height if possible",
+	RunE:         commands.RequireInit(updateCommit),
 	SilenceUsage: true,
 }
 
@@ -23,27 +23,27 @@ func init() {
 	RootCmd.AddCommand(updateCmd)
 }
 
-func updateSeed(cmd *cobra.Command, args []string) error {
+func updateCommit(cmd *cobra.Command, args []string) error {
 	cert, err := commands.GetCertifier()
 	if err != nil {
 		return err
 	}
 
 	h := viper.GetInt(heightFlag)
-	var seed certifiers.Seed
+	var fc certifiers.FullCommit
 	if h <= 0 {
 		// get the lastest from our source
-		seed, err = certifiers.LatestSeed(cert.SeedSource)
+		fc, err = cert.Source.LatestCommit()
 	} else {
-		seed, err = cert.SeedSource.GetByHeight(h)
+		fc, err = cert.Source.GetByHeight(h)
 	}
 	if err != nil {
 		return err
 	}
 
 	// let the certifier do it's magic to update....
-	fmt.Printf("Trying to update to height: %d...\n", seed.Height())
-	err = cert.Update(seed.Checkpoint, seed.Validators)
+	fmt.Printf("Trying to update to height: %d...\n", fc.Height())
+	err = cert.Update(fc)
 	if err != nil {
 		return err
 	}
diff --git a/client/commands/common.go b/client/commands/common.go
index ef8827a990..c51dbb469b 100644
--- a/client/commands/common.go
+++ b/client/commands/common.go
@@ -74,7 +74,7 @@ func GetProviders() (trusted certifiers.Provider, source certifiers.Provider) {
 }
 
 // GetCertifier constructs a dynamic certifier from the config info
-func GetCertifier() (*certifiers.InquiringCertifier, error) {
+func GetCertifier() (*certifiers.Inquiring, error) {
 	// load up the latest store....
 	trust := GetTrustedProvider()
 	source := GetSourceProvider()
diff --git a/client/commands/init.go b/client/commands/init.go
index a54dbb6993..807dd1c0b2 100644
--- a/client/commands/init.go
+++ b/client/commands/init.go
@@ -29,7 +29,7 @@ var (
 
 //nolint
 const (
-	SeedFlag      = "seed"
+	CommitFlag    = "commit"
 	HashFlag      = "valhash"
 	GenesisFlag   = "genesis"
 	FlagTrustNode = "trust-node"
@@ -52,7 +52,7 @@ var ResetCmd = &cobra.Command{
 
 func init() {
 	InitCmd.Flags().Bool("force-reset", false, "Wipe clean an existing client store, except for keys")
-	InitCmd.Flags().String(SeedFlag, "", "Seed file to import (optional)")
+	InitCmd.Flags().String(CommitFlag, "", "Commit file to import (optional)")
 	InitCmd.Flags().String(HashFlag, "", "Trusted validator hash (must match to accept)")
 	InitCmd.Flags().String(GenesisFlag, "", "Genesis file with chainid and validators (optional)")
 }
@@ -92,7 +92,7 @@ func doInit(cmd *cobra.Command, root string) error {
 	if err != nil {
 		return err
 	}
-	err = initSeed()
+	err = initTrust()
 	return err
 }
 
@@ -275,27 +275,27 @@ func initConfigFile(cmd *cobra.Command) error {
 	return nil
 }
 
-func initSeed() (err error) {
+func initTrust() (err error) {
 	// create a provider....
 	trust, source := GetProviders()
 
-	// load a seed file, or get data from the provider
-	var seed certifiers.Seed
-	seedFile := viper.GetString(SeedFlag)
-	if seedFile == "" {
+	// load a commit file, or get data from the provider
+	var fc certifiers.FullCommit
+	commitFile := viper.GetString(CommitFlag)
+	if commitFile == "" {
 		fmt.Println("Loading validator set from tendermint rpc...")
-		seed, err = certifiers.LatestSeed(source)
+		fc, err = source.LatestCommit()
 	} else {
-		fmt.Printf("Loading validators from file %s\n", seedFile)
-		seed, err = certifiers.LoadSeed(seedFile)
+		fmt.Printf("Loading validators from file %s\n", commitFile)
+		fc, err = files.LoadFullCommit(commitFile)
 	}
-	// can't load the seed? abort!
+	// can't load the commit? abort!
 	if err != nil {
 		return err
 	}
 
-	// make sure it is a proper seed
-	err = seed.ValidateBasic(viper.GetString(ChainFlag))
+	// make sure it is a proper commit
+	err = fc.ValidateBasic(viper.GetString(ChainFlag))
 	if err != nil {
 		return err
 	}
@@ -305,30 +305,30 @@ func initSeed() (err error) {
 	if hash != "" {
 		var hashb []byte
 		hashb, err = hex.DecodeString(hash)
-		if err == nil && !bytes.Equal(hashb, seed.Hash()) {
-			err = errors.Errorf("Seed hash doesn't match expectation: %X", seed.Hash())
+		if err == nil && !bytes.Equal(hashb, fc.ValidatorsHash()) {
+			err = errors.Errorf("Validator hash doesn't match expectation: %X", fc.ValidatorsHash())
 		}
 	} else {
-		err = validateHash(seed)
+		err = validateHash(fc)
 	}
 
 	if err != nil {
 		return err
 	}
 
-	// if accepted, store seed as current state
-	trust.StoreSeed(seed)
+	// if accepted, store commit as current state
+	trust.StoreCommit(fc)
 	return nil
 }
 
-func validateHash(seed certifiers.Seed) error {
+func validateHash(fc certifiers.FullCommit) error {
 	// ask the user to verify the validator hash
 	fmt.Println("\nImportant: if this is incorrect, all interaction with the chain will be insecure!")
-	fmt.Printf("  Given validator hash valid: %X\n", seed.Hash())
+	fmt.Printf("  Given validator hash valid: %X\n", fc.ValidatorsHash())
 	fmt.Println("Is this valid (y/n)?")
 	valid := askForConfirmation()
 	if !valid {
-		return errors.New("Invalid validator hash, try init with proper seed later")
+		return errors.New("Invalid validator hash, try init with proper commit later")
 	}
 	return nil
 }
diff --git a/client/commands/query/get.go b/client/commands/query/get.go
index 8e1284c48d..7ffc1c1f5d 100644
--- a/client/commands/query/get.go
+++ b/client/commands/query/get.go
@@ -12,6 +12,7 @@ import (
 	"github.com/tendermint/go-wire/data"
 	"github.com/tendermint/iavl"
 	"github.com/tendermint/light-client/proofs"
+
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 
 	"github.com/cosmos/cosmos-sdk/client"
diff --git a/client/commands/query/tx.go b/client/commands/query/tx.go
index 3826fc932e..8f86c09bb1 100644
--- a/client/commands/query/tx.go
+++ b/client/commands/query/tx.go
@@ -52,7 +52,7 @@ func txQueryCmd(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	check, err := client.GetCertifiedCheckpoint(res.Height, node, cert)
+	check, err := client.GetCertifiedCommit(res.Height, node, cert)
 	if err != nil {
 		return err
 	}
diff --git a/client/common.go b/client/common.go
index f2c0d01412..5e79b8afbd 100644
--- a/client/common.go
+++ b/client/common.go
@@ -5,8 +5,11 @@ import (
 
 	"github.com/tendermint/light-client/certifiers"
 	certclient "github.com/tendermint/light-client/certifiers/client"
+	certerr "github.com/tendermint/light-client/certifiers/errors"
 	"github.com/tendermint/light-client/certifiers/files"
 
+	"github.com/tendermint/light-client/proofs"
+
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 )
 
@@ -18,7 +21,7 @@ func GetNode(url string) rpcclient.Client {
 // GetRPCProvider retuns a certifier compatible data source using
 // tendermint RPC
 func GetRPCProvider(url string) certifiers.Provider {
-	return certclient.NewHTTP(url)
+	return certclient.NewHTTPProvider(url)
 }
 
 // GetLocalProvider returns a reference to a file store of headers
@@ -33,22 +36,22 @@ func GetLocalProvider(dir string) certifiers.Provider {
 // GetCertifier initializes an inquiring certifier given a fixed chainID
 // and a local source of trusted data with at least one seed
 func GetCertifier(chainID string, trust certifiers.Provider,
-	source certifiers.Provider) (*certifiers.InquiringCertifier, error) {
+	source certifiers.Provider) (*certifiers.Inquiring, error) {
 
-	// this gets the most recent verified seed
-	seed, err := certifiers.LatestSeed(trust)
-	if certifiers.IsSeedNotFoundErr(err) {
+	// this gets the most recent verified commit
+	fc, err := trust.LatestCommit()
+	if certerr.IsCommitNotFoundErr(err) {
 		return nil, errors.New("Please run init first to establish a root of trust")
 	}
 	if err != nil {
 		return nil, err
 	}
-	cert := certifiers.NewInquiring(chainID, seed, trust, source)
+	cert := certifiers.NewInquiring(chainID, fc, trust, source)
 	return cert, nil
 }
 
 // SecureClient uses a given certifier to wrap an connection to an untrusted
 // host and return a cryptographically secure rpc client.
-func SecureClient(c rpcclient.Client, cert *certifiers.InquiringCertifier) rpcclient.Client {
-	return certclient.Wrap(c, cert)
+func SecureClient(c rpcclient.Client, cert *certifiers.Inquiring) rpcclient.Client {
+	return proofs.Wrap(c, cert)
 }
diff --git a/client/errors.go b/client/errors.go
new file mode 100644
index 0000000000..9f69f5e129
--- /dev/null
+++ b/client/errors.go
@@ -0,0 +1,22 @@
+package client
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+)
+
+//--------------------------------------------
+
+var errNoData = fmt.Errorf("No data returned for query")
+
+// IsNoDataErr checks whether an error is due to a query returning empty data
+func IsNoDataErr(err error) bool {
+	return errors.Cause(err) == errNoData
+}
+
+func ErrNoData() error {
+	return errors.WithStack(errNoData)
+}
+
+//--------------------------------------------
diff --git a/client/errors_test.go b/client/errors_test.go
new file mode 100644
index 0000000000..c561c35b7a
--- /dev/null
+++ b/client/errors_test.go
@@ -0,0 +1,18 @@
+package client
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestErrorNoData(t *testing.T) {
+	e1 := ErrNoData()
+	e1.Error()
+	assert.True(t, IsNoDataErr(e1))
+
+	e2 := errors.New("foobar")
+	assert.False(t, IsNoDataErr(e2))
+	assert.False(t, IsNoDataErr(nil))
+}
diff --git a/client/query.go b/client/query.go
index c6c0589438..25b3823d6f 100644
--- a/client/query.go
+++ b/client/query.go
@@ -5,8 +5,8 @@ import (
 
 	"github.com/tendermint/go-wire/data"
 	"github.com/tendermint/iavl"
-	lc "github.com/tendermint/light-client"
 	"github.com/tendermint/light-client/certifiers"
+	certerr "github.com/tendermint/light-client/certifiers/errors"
 
 	"github.com/tendermint/tendermint/rpc/client"
 )
@@ -38,7 +38,7 @@ func GetWithProof(key []byte, reqHeight int, node client.Client,
 		return
 	}
 	if len(resp.Key) == 0 || len(resp.Proof) == 0 {
-		err = lc.ErrNoData()
+		err = ErrNoData()
 		return
 	}
 	if resp.Height == 0 {
@@ -47,8 +47,8 @@ func GetWithProof(key []byte, reqHeight int, node client.Client,
 	}
 
 	// AppHash for height H is in header H+1
-	var check lc.Checkpoint
-	check, err = GetCertifiedCheckpoint(int(resp.Height+1), node, cert)
+	var commit *certifiers.Commit
+	commit, err = GetCertifiedCommit(int(resp.Height+1), node, cert)
 	if err != nil {
 		return
 	}
@@ -63,7 +63,7 @@ func GetWithProof(key []byte, reqHeight int, node client.Client,
 		}
 
 		// Validate the proof against the certified header to ensure data integrity.
-		err = eproof.Verify(resp.Key, resp.Value, check.Header.AppHash)
+		err = eproof.Verify(resp.Key, resp.Value, commit.Header.AppHash)
 		if err != nil {
 			err = errors.Wrap(err, "Couldn't verify proof")
 			return
@@ -79,12 +79,12 @@ func GetWithProof(key []byte, reqHeight int, node client.Client,
 			return
 		}
 		// Validate the proof against the certified header to ensure data integrity.
-		err = aproof.Verify(resp.Key, nil, check.Header.AppHash)
+		err = aproof.Verify(resp.Key, nil, commit.Header.AppHash)
 		if err != nil {
 			err = errors.Wrap(err, "Couldn't verify proof")
 			return
 		}
-		err = lc.ErrNoData()
+		err = ErrNoData()
 		proof = aproof
 	}
 
@@ -92,28 +92,25 @@ func GetWithProof(key []byte, reqHeight int, node client.Client,
 	return
 }
 
-// GetCertifiedCheckpoint gets the signed header for a given height
+// GetCertifiedCommit gets the signed header for a given height
 // and certifies it.  Returns error if unable to get a proven header.
-func GetCertifiedCheckpoint(h int, node client.Client,
-	cert certifiers.Certifier) (empty lc.Checkpoint, err error) {
+func GetCertifiedCommit(h int, node client.Client,
+	cert certifiers.Certifier) (empty *certifiers.Commit, err error) {
 
 	// FIXME: cannot use cert.GetByHeight for now, as it also requires
 	// Validators and will fail on querying tendermint for non-current height.
 	// When this is supported, we should use it instead...
 	client.WaitForHeight(node, h, nil)
-	commit, err := node.Commit(&h)
+	cresp, err := node.Commit(&h)
 	if err != nil {
 		return
 	}
-	check := lc.Checkpoint{
-		Header: commit.Header,
-		Commit: commit.Commit,
-	}
+	commit := certifiers.CommitFromResult(cresp)
 
 	// validate downloaded checkpoint with our request and trust store.
-	if check.Height() != h {
-		return empty, lc.ErrHeightMismatch(h, check.Height())
+	if commit.Height() != h {
+		return empty, certerr.ErrHeightMismatch(h, commit.Height())
 	}
-	err = cert.Certify(check)
-	return check, nil
+	err = cert.Certify(commit)
+	return commit, nil
 }
diff --git a/client/query_test.go b/client/query_test.go
index 8faff5599b..0320176eb3 100644
--- a/client/query_test.go
+++ b/client/query_test.go
@@ -9,14 +9,14 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/tendermint/go-wire"
-	lc "github.com/tendermint/light-client"
 	"github.com/tendermint/light-client/certifiers"
 	certclient "github.com/tendermint/light-client/certifiers/client"
+	"github.com/tendermint/tmlibs/log"
+
 	nm "github.com/tendermint/tendermint/node"
 	"github.com/tendermint/tendermint/rpc/client"
 	rpctest "github.com/tendermint/tendermint/rpc/test"
 	"github.com/tendermint/tendermint/types"
-	"github.com/tendermint/tmlibs/log"
 
 	sdkapp "github.com/cosmos/cosmos-sdk/app"
 	"github.com/cosmos/cosmos-sdk/modules/eyes"
@@ -59,13 +59,13 @@ func TestAppProofs(t *testing.T) {
 	brh := br.Height
 
 	// This sets up our trust on the node based on some past point.
-	source := certclient.New(cl)
+	source := certclient.NewProvider(cl)
 	seed, err := source.GetByHeight(br.Height - 2)
 	require.NoError(err, "%+v", err)
 	cert := certifiers.NewStatic("my-chain", seed.Validators)
 
 	client.WaitForHeight(cl, 3, nil)
-	latest, err := source.GetLatestCommit()
+	latest, err := source.LatestCommit()
 	require.NoError(err, "%+v", err)
 	rootHash := latest.Header.AppHash
 
@@ -75,7 +75,7 @@ func TestAppProofs(t *testing.T) {
 	// verify a query before the tx block has no data (and valid non-exist proof)
 	bs, height, proof, err := GetWithProof(k, brh-1, cl, cert)
 	require.NotNil(err)
-	require.True(lc.IsNoDataErr(err))
+	require.True(IsNoDataErr(err))
 	require.Nil(bs)
 
 	// but given that block it is good
@@ -98,7 +98,7 @@ func TestAppProofs(t *testing.T) {
 	// Test non-existing key.
 	missing := []byte("my-missing-key")
 	bs, _, proof, err = GetWithProof(missing, 0, cl, cert)
-	require.True(lc.IsNoDataErr(err))
+	require.True(IsNoDataErr(err))
 	require.Nil(bs)
 	require.NotNil(proof)
 	err = proof.Verify(missing, nil, rootHash)
@@ -122,7 +122,7 @@ func TestTxProofs(t *testing.T) {
 	require.EqualValues(0, br.DeliverTx.Code)
 	fmt.Printf("tx height: %d\n", br.Height)
 
-	source := certclient.New(cl)
+	source := certclient.NewProvider(cl)
 	seed, err := source.GetByHeight(br.Height - 2)
 	require.NoError(err, "%+v", err)
 	cert := certifiers.NewStatic("my-chain", seed.Validators)
@@ -141,8 +141,8 @@ func TestTxProofs(t *testing.T) {
 	err = res.Proof.Validate(key)
 	assert.NoError(err, "%+v", err)
 
-	check, err := GetCertifiedCheckpoint(int(br.Height), cl, cert)
+	commit, err := GetCertifiedCommit(int(br.Height), cl, cert)
 	require.Nil(err, "%+v", err)
-	require.Equal(res.Proof.RootHash, check.Header.DataHash)
+	require.Equal(res.Proof.RootHash, commit.Header.DataHash)
 
 }
diff --git a/docs/architecture/API.md b/docs/architecture/API.md
index ddabc8a8ce..de4abd0614 100644
--- a/docs/architecture/API.md
+++ b/docs/architecture/API.md
@@ -237,7 +237,7 @@ info about self...
 }
 ```
 
-`/seeds`
+`/commits`
 
 ```
 {
@@ -246,4 +246,4 @@ info about self...
 }
 ```
 
-info on last seed
+info on last commit
diff --git a/examples/basecoin/cmd/basecli/main.go b/examples/basecoin/cmd/basecli/main.go
index 6145e8642d..107890a75e 100644
--- a/examples/basecoin/cmd/basecli/main.go
+++ b/examples/basecoin/cmd/basecli/main.go
@@ -9,11 +9,11 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/client/commands"
 	"github.com/cosmos/cosmos-sdk/client/commands/auto"
+	"github.com/cosmos/cosmos-sdk/client/commands/commits"
 	"github.com/cosmos/cosmos-sdk/client/commands/keys"
 	"github.com/cosmos/cosmos-sdk/client/commands/proxy"
 	"github.com/cosmos/cosmos-sdk/client/commands/query"
 	rpccmd "github.com/cosmos/cosmos-sdk/client/commands/rpc"
-	"github.com/cosmos/cosmos-sdk/client/commands/seeds"
 	txcmd "github.com/cosmos/cosmos-sdk/client/commands/txs"
 	authcmd "github.com/cosmos/cosmos-sdk/modules/auth/commands"
 	basecmd "github.com/cosmos/cosmos-sdk/modules/base/commands"
@@ -77,7 +77,7 @@ func main() {
 		commands.InitCmd,
 		commands.ResetCmd,
 		keys.RootCmd,
-		seeds.RootCmd,
+		commits.RootCmd,
 		rpccmd.RootCmd,
 		query.RootCmd,
 		txcmd.RootCmd,
diff --git a/examples/basecoin/tests/cli/ibc.sh b/examples/basecoin/tests/cli/ibc.sh
index 275f4aeae4..ed8a277d96 100755
--- a/examples/basecoin/tests/cli/ibc.sh
+++ b/examples/basecoin/tests/cli/ibc.sh
@@ -84,18 +84,18 @@ test00GetAccount() {
 }
 
 test01RegisterChains() {
-    # let's get the root seeds to cross-register them
-    ROOT_1="$BASE_DIR_1/root_seed.json"
-    ${CLIENT_EXE} seeds export $ROOT_1 --home=${CLIENT_1}
-    assertTrue "line=${LINENO}, export seed failed" $?
+    # let's get the root commits to cross-register them
+    ROOT_1="$BASE_DIR_1/root_commit.json"
+    ${CLIENT_EXE} commits export $ROOT_1 --home=${CLIENT_1}
+    assertTrue "line=${LINENO}, export commit failed" $?
 
-    ROOT_2="$BASE_DIR_2/root_seed.json"
-    ${CLIENT_EXE} seeds export $ROOT_2 --home=${CLIENT_2}
-    assertTrue "line=${LINENO}, export seed failed" $?
+    ROOT_2="$BASE_DIR_2/root_commit.json"
+    ${CLIENT_EXE} commits export $ROOT_2 --home=${CLIENT_2}
+    assertTrue "line=${LINENO}, export commit failed" $?
 
     # register chain2 on chain1
     TX=$(echo qwertyuiop | ${CLIENT_EXE} tx ibc-register \
-        --sequence=1 --seed=${ROOT_2} --name=$POOR --home=${CLIENT_1})
+        --sequence=1 --commit=${ROOT_2} --name=$POOR --home=${CLIENT_1})
     txSucceeded $? "$TX" "register chain2 on chain 1"
     # an example to quit early if there is no point in more tests
     if [ $? != 0 ]; then echo "aborting!"; return 1; fi
@@ -104,40 +104,40 @@ test01RegisterChains() {
 
     # register chain1 on chain2 (no money needed... yet)
     TX=$(echo qwertyuiop | ${CLIENT_EXE} tx ibc-register \
-        --sequence=1 --seed=${ROOT_1} --name=$POOR --home=${CLIENT_2})
+        --sequence=1 --commit=${ROOT_1} --name=$POOR --home=${CLIENT_2})
     txSucceeded $? "$TX" "register chain1 on chain 2"
     # an example to quit early if there is no point in more tests
     if [ $? != 0 ]; then echo "aborting!"; return 1; fi
 }
 
 test02UpdateChains() {
-    # let's get the root seeds to cross-register them
+    # let's get the root commits to cross-register them
     UPDATE_1="$BASE_DIR_1/seed_1.json"
-    ${CLIENT_EXE} seeds update --home=${CLIENT_1}  > /dev/null
-    ${CLIENT_EXE} seeds export $UPDATE_1 --home=${CLIENT_1}
-    assertTrue "line=${LINENO}, export seed failed" $?
+    ${CLIENT_EXE} commits update --home=${CLIENT_1}  > /dev/null
+    ${CLIENT_EXE} commits export $UPDATE_1 --home=${CLIENT_1}
+    assertTrue "line=${LINENO}, export commit failed" $?
     # make sure it is newer than the other....
     assertNewHeight "line=${LINENO}" $ROOT_1 $UPDATE_1
 
     UPDATE_2="$BASE_DIR_2/seed_2.json"
-    ${CLIENT_EXE} seeds update --home=${CLIENT_2} > /dev/null
-    ${CLIENT_EXE} seeds export $UPDATE_2 --home=${CLIENT_2}
-    assertTrue "line=${LINENO}, export seed failed" $?
+    ${CLIENT_EXE} commits update --home=${CLIENT_2} > /dev/null
+    ${CLIENT_EXE} commits export $UPDATE_2 --home=${CLIENT_2}
+    assertTrue "line=${LINENO}, export commit failed" $?
     assertNewHeight "line=${LINENO}" $ROOT_2 $UPDATE_2
     # this is used later to check query data
-    REGISTER_2_HEIGHT=$(cat $ROOT_2 | jq .checkpoint.header.height)
-    UPDATE_2_HEIGHT=$(cat $UPDATE_2 | jq .checkpoint.header.height)
+    REGISTER_2_HEIGHT=$(cat $ROOT_2 | jq .commit.header.height)
+    UPDATE_2_HEIGHT=$(cat $UPDATE_2 | jq .commit.header.height)
 
     # update chain2 on chain1
     TX=$(echo qwertyuiop | ${CLIENT_EXE} tx ibc-update \
-        --sequence=2 --seed=${UPDATE_2} --name=$POOR --home=${CLIENT_1})
+        --sequence=2 --commit=${UPDATE_2} --name=$POOR --home=${CLIENT_1})
     txSucceeded $? "$TX" "update chain2 on chain 1"
     # an example to quit early if there is no point in more tests
     if [ $? != 0 ]; then echo "aborting!"; return 1; fi
 
     # update chain1 on chain2 (no money needed... yet)
     TX=$(echo qwertyuiop | ${CLIENT_EXE} tx ibc-update \
-        --sequence=2 --seed=${UPDATE_1} --name=$POOR --home=${CLIENT_2})
+        --sequence=2 --commit=${UPDATE_1} --name=$POOR --home=${CLIENT_2})
     txSucceeded $? "$TX" "update chain1 on chain 2"
     # an example to quit early if there is no point in more tests
     if [ $? != 0 ]; then echo "aborting!"; return 1; fi
@@ -224,24 +224,24 @@ test05ReceiveIBCPacket() {
 
     # now, we try to post it.... (this is PACKET from last test)
 
-    # get the seed with the proof and post it
+    # get the commit with the proof and post it
     SRC_HEIGHT=$(echo $PACKET | jq .src_height)
     PROOF_HEIGHT=$(expr $SRC_HEIGHT + 1)
     # FIXME: this should auto-update on proofs...
-    ${CLIENT_EXE} seeds update --height=$PROOF_HEIGHT --home=${CLIENT_1}  > /dev/null
-    assertTrue "line=${LINENO}, update seed failed" $?
+    ${CLIENT_EXE} commits update --height=$PROOF_HEIGHT --home=${CLIENT_1}  > /dev/null
+    assertTrue "line=${LINENO}, update commit failed" $?
 
-    PACKET_SEED="$BASE_DIR_1/packet_seed.json"
-    ${CLIENT_EXE} seeds export $PACKET_SEED --home=${CLIENT_1} --height=$PROOF_HEIGHT
-    assertTrue "line=${LINENO}, export seed failed" $?
+    PACKET_COMMIT="$BASE_DIR_1/packet_commit.json"
+    ${CLIENT_EXE} commits export $PACKET_COMMIT --home=${CLIENT_1} --height=$PROOF_HEIGHT
+    assertTrue "line=${LINENO}, export commit failed" $?
     if [ -n "$DEBUG" ]; then
         echo "**** SEED ****"
-        cat $PACKET_SEED | jq .checkpoint.header
+        cat $PACKET_COMMIT | jq .commit.header
         echo
     fi
 
     TX=$(echo qwertyuiop | ${CLIENT_EXE} tx ibc-update \
-        --seed=${PACKET_SEED} --name=$POOR --sequence=3)
+        --commit=${PACKET_COMMIT} --name=$POOR --sequence=3)
     txSucceeded $? "$TX" "prepare packet chain1 on chain 2"
     # an example to quit early if there is no point in more tests
     if [ $? != 0 ]; then echo "aborting!"; return 1; fi
@@ -268,11 +268,11 @@ test05ReceiveIBCPacket() {
 }
 
 # XXX Ex Usage: assertNewHeight $MSG $SEED_1 $SEED_2
-# Desc: Asserts that seed2 has a higher block height than seed 1
+# Desc: Asserts that seed2 has a higher block height than commit 1
 assertNewHeight() {
-    H1=$(cat $2 | jq .checkpoint.header.height)
-    H2=$(cat $3 | jq .checkpoint.header.height)
-    assertTrue "$MSG" "test $H2 -gt $H1"
+    H1=$(cat $2 | jq .commit.header.height)
+    H2=$(cat $3 | jq .commit.header.height)
+    assertTrue "$1" "test $H2 -gt $H1"
     return $?
 }
 
diff --git a/examples/counter/cmd/countercli/main.go b/examples/counter/cmd/countercli/main.go
index 0e7c251e67..d2845aefc9 100644
--- a/examples/counter/cmd/countercli/main.go
+++ b/examples/counter/cmd/countercli/main.go
@@ -8,10 +8,10 @@ import (
 	"github.com/tendermint/tmlibs/cli"
 
 	"github.com/cosmos/cosmos-sdk/client/commands"
+	"github.com/cosmos/cosmos-sdk/client/commands/commits"
 	"github.com/cosmos/cosmos-sdk/client/commands/keys"
 	"github.com/cosmos/cosmos-sdk/client/commands/proxy"
 	"github.com/cosmos/cosmos-sdk/client/commands/query"
-	"github.com/cosmos/cosmos-sdk/client/commands/seeds"
 
 	txcmd "github.com/cosmos/cosmos-sdk/client/commands/txs"
 	bcount "github.com/cosmos/cosmos-sdk/examples/counter/cmd/countercli/commands"
@@ -74,7 +74,7 @@ func main() {
 		commands.ResetCmd,
 		commands.VersionCmd,
 		keys.RootCmd,
-		seeds.RootCmd,
+		commits.RootCmd,
 		query.RootCmd,
 		txcmd.RootCmd,
 		proxy.RootCmd,
diff --git a/examples/eyes/cmd/eyescli/main.go b/examples/eyes/cmd/eyescli/main.go
index 374e59d074..d23a0e8dc3 100644
--- a/examples/eyes/cmd/eyescli/main.go
+++ b/examples/eyes/cmd/eyescli/main.go
@@ -9,9 +9,9 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/client/commands"
 	"github.com/cosmos/cosmos-sdk/client/commands/auto"
+	"github.com/cosmos/cosmos-sdk/client/commands/commits"
 	"github.com/cosmos/cosmos-sdk/client/commands/query"
 	rpccmd "github.com/cosmos/cosmos-sdk/client/commands/rpc"
-	"github.com/cosmos/cosmos-sdk/client/commands/seeds"
 	txcmd "github.com/cosmos/cosmos-sdk/client/commands/txs"
 	eyescmd "github.com/cosmos/cosmos-sdk/modules/eyes/commands"
 )
@@ -50,7 +50,7 @@ func main() {
 		// we use out own init command to not require address arg
 		commands.InitCmd,
 		commands.ResetCmd,
-		seeds.RootCmd,
+		commits.RootCmd,
 		rpccmd.RootCmd,
 		query.RootCmd,
 		txcmd.RootCmd,
diff --git a/glide.lock b/glide.lock
index 2bd6a73941..e0ea8a99dd 100644
--- a/glide.lock
+++ b/glide.lock
@@ -1,22 +1,24 @@
 hash: fbfdd03c0367bb0785ceb81ed34059df219e55d5a9c71c12597e505fbce14165
-updated: 2017-10-23T14:49:22.891642342+02:00
+updated: 2017-10-25T19:24:51.90002008+02:00
 imports:
 - name: github.com/bgentry/speakeasy
   version: 4aabc24848ce5fd31929f7d1e4ea74d3709c14cd
 - name: github.com/btcsuite/btcd
-  version: b8df516b4b267acf2de46be593a9d948d1d2c420
+  version: c7588cbf7690cd9f047a28efa2dcd8f2435a4e5e
   subpackages:
   - btcec
-- name: github.com/btcsuite/fastsha256
-  version: 637e656429416087660c84436a2a035d69d54e2e
 - name: github.com/BurntSushi/toml
   version: a368813c5e648fee92e5f6c30e3944ff9d5e8895
 - name: github.com/ebuchman/fail-test
   version: 95f809107225be108efcf10a3509e4ea6ceef3c4
+- name: github.com/ethanfrey/ledger
+  version: 5e432577be582bd18a3b4a9cd75dae7a317ade36
+- name: github.com/flynn/hid
+  version: ed06a31c6245d4552e8dbba7e32e5b010b875d65
 - name: github.com/fsnotify/fsnotify
   version: 4da3e2cfbabc9f751898f250b49f2439785783a1
 - name: github.com/go-kit/kit
-  version: d67bb4c202e3b91377d1079b110a6c9ce23ab2f8
+  version: e2b298466b32c7cd5579a9b9b07e968fc9d9452c
   subpackages:
   - log
   - log/level
@@ -24,18 +26,21 @@ imports:
 - name: github.com/go-logfmt/logfmt
   version: 390ab7935ee28ec6b286364bba9b4dd6410cb3d5
 - name: github.com/go-playground/locales
-  version: 1e5f1161c6416a5ff48840eb8724a394e48cc534
+  version: e4cbcb5d0652150d40ad0646651076b6bd2be4f6
   subpackages:
   - currency
 - name: github.com/go-playground/universal-translator
   version: 71201497bace774495daed26a3874fd339e0b538
 - name: github.com/go-stack/stack
-  version: 100eb0c0a9c5b306ca2fb4f165df21d80ada4b82
+  version: 817915b46b97fd7bb80e8ab6b69f01a53ac3eebf
 - name: github.com/golang/protobuf
-  version: 18c9bb3261723cd5401db4d0c9fbc5c3b6c70fe8
+  version: 1643683e1b54a9e88ad26d98f81400c8c9d9f4f9
   subpackages:
   - proto
+  - ptypes
   - ptypes/any
+  - ptypes/duration
+  - ptypes/timestamp
 - name: github.com/golang/snappy
   version: 553a641470496b2327abcac10b36396bd98e45c9
 - name: github.com/gorilla/context
@@ -43,9 +48,9 @@ imports:
 - name: github.com/gorilla/mux
   version: 24fca303ac6da784b9e8269f724ddeb0b2eea5e7
 - name: github.com/gorilla/websocket
-  version: a91eba7f97777409bc2c443f5534d41dd20c5720
+  version: 71fa72d4842364bc5f74185f4161e0099ea3624a
 - name: github.com/hashicorp/hcl
-  version: 392dba7d905ed5d04a5794ba89f558b27e2ba1ca
+  version: 23c074d0eceb2b8a5bfdbb271ab780cde70f05a8
   subpackages:
   - hcl/ast
   - hcl/parser
@@ -64,11 +69,11 @@ imports:
 - name: github.com/kr/logfmt
   version: b84e30acd515aadc4b783ad4ff83aff3299bdfe0
 - name: github.com/magiconair/properties
-  version: 51463bfca2576e06c62a8504b5c0f06d61312647
+  version: 8d7837e64d3c1ee4e54a880c5a920ab4316fc90a
 - name: github.com/mattn/go-isatty
   version: a5cdd64afdee435007ee3e9f6ed4684af949d568
 - name: github.com/mitchellh/mapstructure
-  version: cc8532a8e9a55ea36402aa21efdf403a60d34096
+  version: 06020f85339e21b2478f756a78e295255ffa4d6a
 - name: github.com/pelletier/go-buffruneio
   version: c37440a7cf42ac63b919c752ca73a85067e05992
 - name: github.com/pelletier/go-toml
@@ -78,21 +83,21 @@ imports:
 - name: github.com/rcrowley/go-metrics
   version: 1f30fe9094a513ce4c700b9a54458bbb0c96996c
 - name: github.com/spf13/afero
-  version: 9be650865eab0c12963d8753212f4f9c66cdcf12
+  version: 5660eeed305fe5f69c8fc6cf899132a459a97064
   subpackages:
   - mem
 - name: github.com/spf13/cast
   version: acbeb36b902d72a7a4c18e8f3241075e7ab763e4
 - name: github.com/spf13/cobra
-  version: 4cdb38c072b86bf795d2c81de50784d9fdd6eb77
+  version: 7b2c5ac9fc04fc5efafb60700713d4fa609b777b
 - name: github.com/spf13/jwalterweatherman
-  version: 8f07c835e5cc1450c082fe3a439cf87b0cbb2d99
+  version: 12bd96e66386c1960ab0f74ced1362f66f552f7b
 - name: github.com/spf13/pflag
-  version: e57e3eeb33f795204c1ca35f56c44f83227c6e66
+  version: 97afa5e7ca8a08a383cb259e06636b5e2cc7897f
 - name: github.com/spf13/viper
-  version: 0967fc9aceab2ce9da34061253ac10fb99bba5b2
+  version: 8ef37cbca71638bf32f3d5e194117d4cb46da163
 - name: github.com/syndtr/goleveldb
-  version: 8c81ea47d4c41a385645e133e15510fc6a2a74b4
+  version: b89cc31ef7977104127d34c1bd31ebd1a9db2199
   subpackages:
   - leveldb
   - leveldb/cache
@@ -119,7 +124,7 @@ imports:
   - edwards25519
   - extra25519
 - name: github.com/tendermint/go-crypto
-  version: 8e7f0e7701f92206679ad093d013b9b162427631
+  version: 0a5b1d979a1bc86200c9ff829fbbcd575799a1b6
   subpackages:
   - bcrypt
   - keys
@@ -127,22 +132,24 @@ imports:
   - keys/storage/filestorage
   - keys/storage/memstorage
   - keys/wordlist
+  - nano
 - name: github.com/tendermint/go-wire
-  version: 55ae61f1fc83cfaa57ab7d54250d7a1a2be0b83c
+  version: 99d2169a1e39c65983eacaa1da867d6f3218e1c9
   subpackages:
   - data
   - data/base58
 - name: github.com/tendermint/iavl
-  version: 721710e7aa59f61dbfbf558943a207ba3fe6b926
+  version: 595f3dcd5b6cd4a292e90757ae6d367fd7a6e653
 - name: github.com/tendermint/light-client
-  version: 569e1583da8a52e499764533f3a05d05be6d56d6
+  version: 76313d625e662ed7b284d066d68ff71edd7a9fac
   subpackages:
   - certifiers
   - certifiers/client
+  - certifiers/errors
   - certifiers/files
   - proofs
 - name: github.com/tendermint/tendermint
-  version: fa56e8c0ce463f77c87ab17a3d7cf5431d9f2c0b
+  version: b2d5546cf8f71e0e168072e118d9836862384e6c
   subpackages:
   - blockchain
   - cmd/tendermint/commands
@@ -170,7 +177,7 @@ imports:
   - types
   - version
 - name: github.com/tendermint/tmlibs
-  version: 8e5266a9ef2527e68a1571f932db8228a331b556
+  version: 0a652499ead7cd20a57a6a592f0491a2b493bb85
   subpackages:
   - autofile
   - cli
@@ -184,7 +191,7 @@ imports:
   - logger
   - merkle
 - name: golang.org/x/crypto
-  version: c7af5bf2638a1164f2eb5467c39c6cffbd13a02e
+  version: edd5e9b0879d13ee6970a50153d85b8fec9f7686
   subpackages:
   - blowfish
   - curve25519
@@ -196,7 +203,7 @@ imports:
   - ripemd160
   - salsa20/salsa
 - name: golang.org/x/net
-  version: feeb485667d1fdabe727840fe00adc22431bc86e
+  version: cd69bc3fc700721b709c3a59e16e24c67b58f6ff
   subpackages:
   - context
   - http2
@@ -206,43 +213,49 @@ imports:
   - lex/httplex
   - trace
 - name: golang.org/x/sys
-  version: e62c3de784db939836898e5c19ffd41bece347da
+  version: 8dbc5d05d6edcc104950cc299a1ce6641235bc86
   subpackages:
   - unix
 - name: golang.org/x/text
-  version: 470f45bf29f4147d6fbd7dfd0a02a848e49f5bf4
+  version: c01e4764d870b77f8abe5096ee19ad20d80e8075
   subpackages:
   - secure/bidirule
   - transform
   - unicode/bidi
   - unicode/norm
 - name: google.golang.org/genproto
-  version: 411e09b969b1170a9f0c467558eb4c4c110d9c77
+  version: f676e0f3ac6395ff1a529ae59a6670878a8371a6
   subpackages:
   - googleapis/rpc/status
 - name: google.golang.org/grpc
-  version: 844f573616520565fdc6fb4db242321b5456fd6d
+  version: a5986a5c88227370a9c0a82e5277167229c034cd
   subpackages:
+  - balancer
+  - balancer/roundrobin
   - codes
+  - connectivity
   - credentials
-  - grpclb/grpc_lb_v1
+  - grpclb/grpc_lb_v1/messages
   - grpclog
   - internal
   - keepalive
   - metadata
   - naming
   - peer
+  - resolver
+  - resolver/dns
+  - resolver/passthrough
   - stats
   - status
   - tap
   - transport
 - name: gopkg.in/go-playground/validator.v9
-  version: 6d8c18553ea1ac493d049edd6f102f52e618f085
+  version: 1304298bf10d085adec514b076772a79c9cadb6b
 - name: gopkg.in/yaml.v2
-  version: cd8b52f8269e0feb286dfeef29f8fe4d5b397e0b
+  version: eb3733d160e74a9c7e442f435eb3bea458e1d19f
 testImports:
 - name: github.com/davecgh/go-spew
-  version: 6d212800a42e8ab5c146b8ace3490ee17e5225f9
+  version: 04cdfd42973bb9c8589fd6a731800cf222fde1a9
   subpackages:
   - spew
 - name: github.com/pmezard/go-difflib
@@ -250,7 +263,7 @@ testImports:
   subpackages:
   - difflib
 - name: github.com/stretchr/testify
-  version: 69483b4bd14f5845b5a1e55bca19e954e827f1d0
+  version: 2aa2c176b9dab406a6970f6a55f513e8a8c8b18f
   subpackages:
   - assert
   - require
diff --git a/modules/coin/commands/query.go b/modules/coin/commands/query.go
index c1e0d9f550..1b13bdd2ac 100644
--- a/modules/coin/commands/query.go
+++ b/modules/coin/commands/query.go
@@ -5,8 +5,7 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
-	lc "github.com/tendermint/light-client"
-
+	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/client/commands"
 	"github.com/cosmos/cosmos-sdk/client/commands/query"
 	"github.com/cosmos/cosmos-sdk/modules/coin"
@@ -35,7 +34,7 @@ func accountQueryCmd(cmd *cobra.Command, args []string) error {
 	acc := coin.Account{}
 	prove := !viper.GetBool(commands.FlagTrustNode)
 	height, err := query.GetParsed(key, &acc, query.GetHeight(), prove)
-	if lc.IsNoDataErr(err) {
+	if client.IsNoDataErr(err) {
 		return errors.Errorf("Account bytes are empty for address %s ", addr)
 	} else if err != nil {
 		return err
diff --git a/modules/coin/handler_test.go b/modules/coin/handler_test.go
index 3df51d8e56..20941a8604 100644
--- a/modules/coin/handler_test.go
+++ b/modules/coin/handler_test.go
@@ -252,7 +252,7 @@ func TestSetIssuer(t *testing.T) {
 	}{
 		{sdk.Actor{App: "sig", Address: []byte("gwkfgk")}},
 		// and set back to empty (nil is valid, but assert.Equals doesn't match)
-		{sdk.Actor{Address: []byte{}}},
+		{sdk.Actor{}},
 		{sdk.Actor{ChainID: "other", App: "role", Address: []byte("vote")}},
 	}
 
diff --git a/modules/coin/rest/handlers.go b/modules/coin/rest/handlers.go
index 6deaf44941..a7362c706d 100644
--- a/modules/coin/rest/handlers.go
+++ b/modules/coin/rest/handlers.go
@@ -10,6 +10,7 @@ import (
 	"github.com/spf13/viper"
 
 	sdk "github.com/cosmos/cosmos-sdk"
+	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/client/commands"
 	"github.com/cosmos/cosmos-sdk/client/commands/query"
 	"github.com/cosmos/cosmos-sdk/modules/auth"
@@ -18,7 +19,6 @@ import (
 	"github.com/cosmos/cosmos-sdk/modules/fee"
 	"github.com/cosmos/cosmos-sdk/modules/nonce"
 	"github.com/cosmos/cosmos-sdk/stack"
-	lightclient "github.com/tendermint/light-client"
 	"github.com/tendermint/tmlibs/common"
 )
 
@@ -62,7 +62,7 @@ func doQueryAccount(w http.ResponseWriter, r *http.Request) {
 	account := new(coin.Account)
 	prove := !viper.GetBool(commands.FlagTrustNode)
 	height, err := query.GetParsed(key, account, h, prove)
-	if lightclient.IsNoDataErr(err) {
+	if client.IsNoDataErr(err) {
 		err := fmt.Errorf("account bytes are empty for address: %q", signature)
 		common.WriteError(w, err)
 		return
diff --git a/modules/ibc/commands/tx.go b/modules/ibc/commands/tx.go
index 487803ca58..292658721c 100644
--- a/modules/ibc/commands/tx.go
+++ b/modules/ibc/commands/tx.go
@@ -39,36 +39,36 @@ var PostPacketTxCmd = &cobra.Command{
 
 //nolint
 const (
-	FlagSeed   = "seed"
+	FlagCommit = "commit"
 	FlagPacket = "packet"
 )
 
 func init() {
 	fs1 := RegisterChainTxCmd.Flags()
-	fs1.String(FlagSeed, "", "Filename with a seed file")
+	fs1.String(FlagCommit, "", "Filename with a commit file")
 
 	fs2 := UpdateChainTxCmd.Flags()
-	fs2.String(FlagSeed, "", "Filename with a seed file")
+	fs2.String(FlagCommit, "", "Filename with a commit file")
 
 	fs3 := PostPacketTxCmd.Flags()
 	fs3.String(FlagPacket, "", "Filename with a packet to post")
 }
 
 func registerChainTxCmd(cmd *cobra.Command, args []string) error {
-	seed, err := readSeed()
+	fc, err := readCommit()
 	if err != nil {
 		return err
 	}
-	tx := ibc.RegisterChainTx{seed}.Wrap()
+	tx := ibc.RegisterChainTx{fc}.Wrap()
 	return txcmd.DoTx(tx)
 }
 
 func updateChainTxCmd(cmd *cobra.Command, args []string) error {
-	seed, err := readSeed()
+	fc, err := readCommit()
 	if err != nil {
 		return err
 	}
-	tx := ibc.UpdateChainTx{seed}.Wrap()
+	tx := ibc.UpdateChainTx{fc}.Wrap()
 	return txcmd.DoTx(tx)
 }
 
@@ -80,13 +80,13 @@ func postPacketTxCmd(cmd *cobra.Command, args []string) error {
 	return txcmd.DoTx(post.Wrap())
 }
 
-func readSeed() (seed certifiers.Seed, err error) {
-	name := viper.GetString(FlagSeed)
+func readCommit() (fc certifiers.FullCommit, err error) {
+	name := viper.GetString(FlagCommit)
 	if name == "" {
-		return seed, errors.New("You must specify a seed file")
+		return fc, errors.New("You must specify a commit file")
 	}
 
-	err = readFile(name, &seed)
+	err = readFile(name, &fc)
 	return
 }
 
diff --git a/modules/ibc/handler.go b/modules/ibc/handler.go
index 63bebc3ed1..47b8c56975 100644
--- a/modules/ibc/handler.go
+++ b/modules/ibc/handler.go
@@ -100,20 +100,20 @@ func (h Handler) DeliverTx(ctx sdk.Context, store state.SimpleDB, tx sdk.Tx) (re
 
 	switch t := tx.Unwrap().(type) {
 	case RegisterChainTx:
-		return h.initSeed(ctx, store, t)
+		return h.registerChain(ctx, store, t)
 	case UpdateChainTx:
-		return h.updateSeed(ctx, store, t)
+		return h.updateChain(ctx, store, t)
 	case CreatePacketTx:
 		return h.createPacket(ctx, store, t)
 	}
 	return res, errors.ErrUnknownTxType(tx.Unwrap())
 }
 
-// initSeed imports the first seed for this chain and
+// registerChain imports the first seed for this chain and
 // accepts it as the root of trust.
 //
 // only the registrar, if set, is allowed to do this
-func (h Handler) initSeed(ctx sdk.Context, store state.SimpleDB,
+func (h Handler) registerChain(ctx sdk.Context, store state.SimpleDB,
 	t RegisterChainTx) (res sdk.DeliverResult, err error) {
 
 	info := LoadInfo(store)
@@ -124,20 +124,20 @@ func (h Handler) initSeed(ctx sdk.Context, store state.SimpleDB,
 	// verify that the header looks reasonable
 	chainID := t.ChainID()
 	s := NewChainSet(store)
-	err = s.Register(chainID, ctx.BlockHeight(), t.Seed.Height())
+	err = s.Register(chainID, ctx.BlockHeight(), t.Commit.Height())
 	if err != nil {
 		return res, err
 	}
 
 	space := stack.PrefixedStore(chainID, store)
 	provider := newDBProvider(space)
-	err = provider.StoreSeed(t.Seed)
+	err = provider.StoreCommit(t.Commit)
 	return res, err
 }
 
-// updateSeed checks the seed against the existing chain data and rejects it if it
+// updateChain checks the seed against the existing chain data and rejects it if it
 // doesn't fit (or no chain data)
-func (h Handler) updateSeed(ctx sdk.Context, store state.SimpleDB,
+func (h Handler) updateChain(ctx sdk.Context, store state.SimpleDB,
 	t UpdateChainTx) (res sdk.DeliverResult, err error) {
 
 	chainID := t.ChainID()
@@ -147,21 +147,21 @@ func (h Handler) updateSeed(ctx sdk.Context, store state.SimpleDB,
 	}
 
 	// load the certifier for this chain
-	seed := t.Seed
+	fc := t.Commit
 	space := stack.PrefixedStore(chainID, store)
-	cert, err := newCertifier(space, chainID, seed.Height())
+	cert, err := newCertifier(space, chainID, fc.Height())
 	if err != nil {
 		return res, err
 	}
 
-	// this will import the seed if it is valid in the current context
-	err = cert.Update(seed.Checkpoint, seed.Validators)
+	// this will import the commit if it is valid in the current context
+	err = cert.Update(fc)
 	if err != nil {
 		return res, ErrInvalidCommit(err)
 	}
 
 	// update the tracked height in chain info
-	err = s.Update(chainID, t.Seed.Height())
+	err = s.Update(chainID, fc.Height())
 	return res, err
 }
 
diff --git a/modules/ibc/ibc_test.go b/modules/ibc/ibc_test.go
index 7300746ca2..ceb92237fd 100644
--- a/modules/ibc/ibc_test.go
+++ b/modules/ibc/ibc_test.go
@@ -27,28 +27,28 @@ func TestIBCRegister(t *testing.T) {
 	appHash := []byte{0, 4, 7, 23}
 	appHash2 := []byte{12, 34, 56, 78}
 
-	// badSeed doesn't validate
-	badSeed := genEmptySeed(keys2, "chain-2", 123, appHash, len(keys2))
-	badSeed.Header.AppHash = appHash2
+	// badCommit doesn't validate
+	badCommit := genEmptyCommit(keys2, "chain-2", 123, appHash, len(keys2))
+	badCommit.Header.AppHash = appHash2
 
 	cases := []struct {
-		seed    certifiers.Seed
+		fc      certifiers.FullCommit
 		checker errors.CheckErr
 	}{
 		{
-			genEmptySeed(keys, "chain-1", 100, appHash, len(keys)),
+			genEmptyCommit(keys, "chain-1", 100, appHash, len(keys)),
 			errors.NoErr,
 		},
 		{
-			genEmptySeed(keys, "chain-1", 200, appHash, len(keys)),
+			genEmptyCommit(keys, "chain-1", 200, appHash, len(keys)),
 			IsAlreadyRegisteredErr,
 		},
 		{
-			badSeed,
+			badCommit,
 			IsInvalidCommitErr,
 		},
 		{
-			genEmptySeed(keys2, "chain-2", 123, appHash2, 5),
+			genEmptyCommit(keys2, "chain-2", 123, appHash2, 5),
 			errors.NoErr,
 		},
 	}
@@ -58,7 +58,7 @@ func TestIBCRegister(t *testing.T) {
 	app := stack.New().Dispatch(stack.WrapHandler(NewHandler()))
 
 	for i, tc := range cases {
-		tx := RegisterChainTx{tc.seed}.Wrap()
+		tx := RegisterChainTx{tc.fc}.Wrap()
 		_, err := app.DeliverTx(ctx, store, tx)
 		assert.True(tc.checker(err), "%d: %+v", i, err)
 	}
@@ -78,45 +78,45 @@ func TestIBCRegisterPermissions(t *testing.T) {
 	foobaz := sdk.Actor{App: "foo", Address: []byte("baz")}
 
 	cases := []struct {
-		seed      certifiers.Seed
+		seed      certifiers.FullCommit
 		registrar sdk.Actor
 		signer    sdk.Actor
 		checker   errors.CheckErr
 	}{
 		// no sig, no registrar
 		{
-			seed:    genEmptySeed(keys, "chain-1", 100, appHash, len(keys)),
+			seed:    genEmptyCommit(keys, "chain-1", 100, appHash, len(keys)),
 			checker: errors.NoErr,
 		},
 		// sig, no registrar
 		{
-			seed:    genEmptySeed(keys, "chain-2", 100, appHash, len(keys)),
+			seed:    genEmptyCommit(keys, "chain-2", 100, appHash, len(keys)),
 			signer:  foobaz,
 			checker: errors.NoErr,
 		},
 		// registrar, no sig
 		{
-			seed:      genEmptySeed(keys, "chain-3", 100, appHash, len(keys)),
+			seed:      genEmptyCommit(keys, "chain-3", 100, appHash, len(keys)),
 			registrar: foobar,
 			checker:   errors.IsUnauthorizedErr,
 		},
 		// registrar, wrong sig
 		{
-			seed:      genEmptySeed(keys, "chain-4", 100, appHash, len(keys)),
+			seed:      genEmptyCommit(keys, "chain-4", 100, appHash, len(keys)),
 			signer:    foobaz,
 			registrar: foobar,
 			checker:   errors.IsUnauthorizedErr,
 		},
 		// registrar, wrong sig
 		{
-			seed:      genEmptySeed(keys, "chain-5", 100, appHash, len(keys)),
+			seed:      genEmptyCommit(keys, "chain-5", 100, appHash, len(keys)),
 			signer:    baz,
 			registrar: foobar,
 			checker:   errors.IsUnauthorizedErr,
 		},
 		// registrar, proper sig
 		{
-			seed:      genEmptySeed(keys, "chain-6", 100, appHash, len(keys)),
+			seed:      genEmptyCommit(keys, "chain-6", 100, appHash, len(keys)),
 			signer:    foobar,
 			registrar: foobar,
 			checker:   errors.NoErr,
@@ -151,7 +151,7 @@ func TestIBCUpdate(t *testing.T) {
 	keys := certifiers.GenValKeys(7)
 	appHash := []byte{0, 4, 7, 23}
 	start := 100 // initial height
-	root := genEmptySeed(keys, "chain-1", 100, appHash, len(keys))
+	root := genEmptyCommit(keys, "chain-1", 100, appHash, len(keys))
 
 	keys2 := keys.Extend(2)
 	keys3 := keys2.Extend(2)
@@ -165,53 +165,53 @@ func TestIBCUpdate(t *testing.T) {
 	require.Nil(err, "%+v", err)
 
 	cases := []struct {
-		seed    certifiers.Seed
+		fc      certifiers.FullCommit
 		checker errors.CheckErr
 	}{
 		// same validator, higher up
 		{
-			genEmptySeed(keys, "chain-1", start+50, []byte{22}, len(keys)),
+			genEmptyCommit(keys, "chain-1", start+50, []byte{22}, len(keys)),
 			errors.NoErr,
 		},
 		// same validator, between existing (not most recent)
 		{
-			genEmptySeed(keys, "chain-1", start+5, []byte{15, 43}, len(keys)),
+			genEmptyCommit(keys, "chain-1", start+5, []byte{15, 43}, len(keys)),
 			errors.NoErr,
 		},
 		// same validators, before root of trust
 		{
-			genEmptySeed(keys, "chain-1", start-8, []byte{11, 77}, len(keys)),
+			genEmptyCommit(keys, "chain-1", start-8, []byte{11, 77}, len(keys)),
 			IsHeaderNotFoundErr,
 		},
 		// insufficient signatures
 		{
-			genEmptySeed(keys, "chain-1", start+60, []byte{24}, len(keys)/2),
+			genEmptyCommit(keys, "chain-1", start+60, []byte{24}, len(keys)/2),
 			IsInvalidCommitErr,
 		},
 		// unregistered chain
 		{
-			genEmptySeed(keys, "chain-2", start+60, []byte{24}, len(keys)/2),
+			genEmptyCommit(keys, "chain-2", start+60, []byte{24}, len(keys)/2),
 			IsNotRegisteredErr,
 		},
 		// too much change (keys -> keys3)
 		{
-			genEmptySeed(keys3, "chain-1", start+100, []byte{22}, len(keys3)),
+			genEmptyCommit(keys3, "chain-1", start+100, []byte{22}, len(keys3)),
 			IsInvalidCommitErr,
 		},
 		// legit update to validator set (keys -> keys2)
 		{
-			genEmptySeed(keys2, "chain-1", start+90, []byte{33}, len(keys2)),
+			genEmptyCommit(keys2, "chain-1", start+90, []byte{33}, len(keys2)),
 			errors.NoErr,
 		},
 		// now impossible jump works (keys -> keys2 -> keys3)
 		{
-			genEmptySeed(keys3, "chain-1", start+100, []byte{44}, len(keys3)),
+			genEmptyCommit(keys3, "chain-1", start+100, []byte{44}, len(keys3)),
 			errors.NoErr,
 		},
 	}
 
 	for i, tc := range cases {
-		tx := UpdateChainTx{tc.seed}.Wrap()
+		tx := UpdateChainTx{tc.fc}.Wrap()
 		_, err := app.DeliverTx(ctx, store, tx)
 		assert.True(tc.checker(err), "%d: %+v", i, err)
 	}
@@ -227,7 +227,7 @@ func TestIBCCreatePacket(t *testing.T) {
 	appHash := []byte{1, 2, 3, 4}
 	start := 100 // initial height
 	chainID := "cosmos-hub"
-	root := genEmptySeed(keys, chainID, start, appHash, len(keys))
+	root := genEmptyCommit(keys, chainID, start, appHash, len(keys))
 
 	// create the app and register the root of trust (for chain-1)
 	ctx := stack.MockContext("hub", 50)
diff --git a/modules/ibc/provider.go b/modules/ibc/provider.go
index e308eb79d4..712b6ee81d 100644
--- a/modules/ibc/provider.go
+++ b/modules/ibc/provider.go
@@ -3,6 +3,7 @@ package ibc
 import (
 	wire "github.com/tendermint/go-wire"
 	"github.com/tendermint/light-client/certifiers"
+	certerr "github.com/tendermint/light-client/certifiers/errors"
 
 	"github.com/cosmos/cosmos-sdk/stack"
 	"github.com/cosmos/cosmos-sdk/state"
@@ -17,26 +18,26 @@ const (
 // newCertifier loads up the current state of this chain to make a proper certifier
 // it will load the most recent height before block h if h is positive
 // if h < 0, it will load the latest height
-func newCertifier(store state.SimpleDB, chainID string, h int) (*certifiers.InquiringCertifier, error) {
+func newCertifier(store state.SimpleDB, chainID string, h int) (*certifiers.Inquiring, error) {
 	// each chain has their own prefixed subspace
 	p := newDBProvider(store)
 
-	var seed certifiers.Seed
+	var fc certifiers.FullCommit
 	var err error
 	if h > 0 {
-		// this gets the most recent verified seed below the specified height
-		seed, err = p.GetByHeight(h)
+		// this gets the most recent verified commit below the specified height
+		fc, err = p.GetByHeight(h)
 	} else {
-		// 0 or negative means start at latest seed
-		seed, err = certifiers.LatestSeed(p)
+		// 0 or negative means start at latest commit
+		fc, err = p.LatestCommit()
 	}
 	if err != nil {
 		return nil, ErrHeaderNotFound(h)
 	}
 
 	// we have no source for untrusted keys, but use the db to load trusted history
-	cert := certifiers.NewInquiring(chainID, seed, p,
-		certifiers.MissingProvider{})
+	cert := certifiers.NewInquiring(chainID, fc, p,
+		certifiers.NewMissingProvider())
 	return cert, nil
 }
 
@@ -55,40 +56,49 @@ func newDBProvider(store state.SimpleDB) *dbProvider {
 
 var _ certifiers.Provider = &dbProvider{}
 
-func (d *dbProvider) StoreSeed(seed certifiers.Seed) error {
+func (d *dbProvider) StoreCommit(fc certifiers.FullCommit) error {
 	// TODO: don't duplicate data....
-	b := wire.BinaryBytes(seed)
-	d.byHash.Set(seed.Hash(), b)
-	d.byHeight.Set(uint64(seed.Height()), b)
+	b := wire.BinaryBytes(fc)
+	d.byHash.Set(fc.ValidatorsHash(), b)
+	d.byHeight.Set(uint64(fc.Height()), b)
 	return nil
 }
 
-func (d *dbProvider) GetByHeight(h int) (seed certifiers.Seed, err error) {
-	b, _ := d.byHeight.LTE(uint64(h))
+func (d *dbProvider) LatestCommit() (fc certifiers.FullCommit, err error) {
+	b, _ := d.byHeight.Top()
 	if b == nil {
-		return seed, certifiers.ErrSeedNotFound()
+		return fc, certerr.ErrCommitNotFound()
 	}
-	err = wire.ReadBinaryBytes(b, &seed)
+	err = wire.ReadBinaryBytes(b, &fc)
 	return
 }
 
-func (d *dbProvider) GetByHash(hash []byte) (seed certifiers.Seed, err error) {
+func (d *dbProvider) GetByHeight(h int) (fc certifiers.FullCommit, err error) {
+	b, _ := d.byHeight.LTE(uint64(h))
+	if b == nil {
+		return fc, certerr.ErrCommitNotFound()
+	}
+	err = wire.ReadBinaryBytes(b, &fc)
+	return
+}
+
+func (d *dbProvider) GetByHash(hash []byte) (fc certifiers.FullCommit, err error) {
 	b := d.byHash.Get(hash)
 	if b == nil {
-		return seed, certifiers.ErrSeedNotFound()
+		return fc, certerr.ErrCommitNotFound()
 	}
-	err = wire.ReadBinaryBytes(b, &seed)
+	err = wire.ReadBinaryBytes(b, &fc)
 	return
 }
 
 // GetExactHeight is like GetByHeight, but returns an error instead of
 // closest match if there is no exact match
-func (d *dbProvider) GetExactHeight(h int) (seed certifiers.Seed, err error) {
-	seed, err = d.GetByHeight(h)
+func (d *dbProvider) GetExactHeight(h int) (fc certifiers.FullCommit, err error) {
+	fc, err = d.GetByHeight(h)
 	if err != nil {
 		return
 	}
-	if seed.Height() != h {
+	if fc.Height() != h {
 		err = ErrHeaderNotFound(h)
 	}
 	return
diff --git a/modules/ibc/provider_test.go b/modules/ibc/provider_test.go
index 96d0ad0ae1..2318f97965 100644
--- a/modules/ibc/provider_test.go
+++ b/modules/ibc/provider_test.go
@@ -8,21 +8,22 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/state"
 	"github.com/tendermint/light-client/certifiers"
+	certerr "github.com/tendermint/light-client/certifiers/errors"
 )
 
-func assertSeedEqual(t *testing.T, s, s2 certifiers.Seed) {
+func assertCommitsEqual(t *testing.T, fc, fc2 certifiers.FullCommit) {
 	assert := assert.New(t)
-	assert.Equal(s.Height(), s2.Height())
-	assert.Equal(s.Hash(), s2.Hash())
+	assert.Equal(fc.Height(), fc2.Height())
+	assert.Equal(fc.ValidatorsHash(), fc2.ValidatorsHash())
 	// TODO: more
 }
 
 func TestProviderStore(t *testing.T) {
 	assert, require := assert.New(t), require.New(t)
 
-	// make a few seeds
+	// make a few commits
 	keys := certifiers.GenValKeys(2)
-	seeds := makeSeeds(keys, 4, "some-chain", "demo-store")
+	commits := makeCommits(keys, 4, "some-chain", "demo-store")
 
 	// make a provider
 	store := state.NewMemKVStore()
@@ -31,41 +32,41 @@ func TestProviderStore(t *testing.T) {
 	// check it...
 	_, err := p.GetByHeight(20)
 	require.NotNil(err)
-	assert.True(certifiers.IsSeedNotFoundErr(err))
+	assert.True(certerr.IsCommitNotFoundErr(err))
 
-	// add a seed
-	for _, s := range seeds {
-		err = p.StoreSeed(s)
+	// add commits
+	for _, fc := range commits {
+		err = p.StoreCommit(fc)
 		require.Nil(err)
 	}
 
 	// make sure we get it...
-	s := seeds[0]
-	val, err := p.GetByHeight(s.Height())
+	fc := commits[0]
+	val, err := p.GetByHeight(fc.Height())
 	if assert.Nil(err) {
-		assertSeedEqual(t, s, val)
+		assertCommitsEqual(t, fc, val)
 	}
 
 	// make sure we get higher
-	val, err = p.GetByHeight(s.Height() + 2)
+	val, err = p.GetByHeight(fc.Height() + 2)
 	if assert.Nil(err) {
-		assertSeedEqual(t, s, val)
+		assertCommitsEqual(t, fc, val)
 	}
 
 	// below is nothing
-	_, err = p.GetByHeight(s.Height() - 2)
-	assert.True(certifiers.IsSeedNotFoundErr(err))
+	_, err = p.GetByHeight(fc.Height() - 2)
+	assert.True(certerr.IsCommitNotFoundErr(err))
 
 	// make sure we get highest
-	val, err = certifiers.LatestSeed(p)
+	val, err = p.LatestCommit()
 	if assert.Nil(err) {
-		assertSeedEqual(t, seeds[3], val)
+		assertCommitsEqual(t, commits[3], val)
 	}
 
 	// make sure by hash also (note all have same hash, so overwritten)
-	val, err = p.GetByHash(seeds[1].Hash())
+	val, err = p.GetByHash(commits[1].ValidatorsHash())
 	if assert.Nil(err) {
-		assertSeedEqual(t, seeds[3], val)
+		assertCommitsEqual(t, commits[3], val)
 	}
 }
 
@@ -75,18 +76,17 @@ func TestDBProvider(t *testing.T) {
 	checkProvider(t, p, "test-db", "bling")
 }
 
-func makeSeeds(keys certifiers.ValKeys, count int, chainID, app string) []certifiers.Seed {
+func makeCommits(keys certifiers.ValKeys, count int, chainID, app string) []certifiers.FullCommit {
 	appHash := []byte(app)
-	seeds := make([]certifiers.Seed, count)
+	commits := make([]certifiers.FullCommit, count)
 	for i := 0; i < count; i++ {
-		// two seeds for each validator, to check how we handle dups
+		// two commits for each validator, to check how we handle dups
 		// (10, 0), (10, 1), (10, 1), (10, 2), (10, 2), ...
 		vals := keys.ToValidators(10, int64(count/2))
 		h := 20 + 10*i
-		check := keys.GenCheckpoint(chainID, h, nil, vals, appHash, 0, len(keys))
-		seeds[i] = certifiers.Seed{check, vals}
+		commits[i] = keys.GenFullCommit(chainID, h, nil, vals, appHash, 0, len(keys))
 	}
-	return seeds
+	return commits
 }
 
 func checkProvider(t *testing.T, p certifiers.Provider, chainID, app string) {
@@ -94,43 +94,43 @@ func checkProvider(t *testing.T, p certifiers.Provider, chainID, app string) {
 	keys := certifiers.GenValKeys(5)
 	count := 10
 
-	// make a bunch of seeds...
-	seeds := makeSeeds(keys, count, chainID, app)
+	// make a bunch of commits...
+	commits := makeCommits(keys, count, chainID, app)
 
 	// check provider is empty
-	seed, err := p.GetByHeight(20)
+	fc, err := p.GetByHeight(20)
 	require.NotNil(err)
-	assert.True(certifiers.IsSeedNotFoundErr(err))
+	assert.True(certerr.IsCommitNotFoundErr(err))
 
-	seed, err = p.GetByHash(seeds[3].Hash())
+	fc, err = p.GetByHash(commits[3].ValidatorsHash())
 	require.NotNil(err)
-	assert.True(certifiers.IsSeedNotFoundErr(err))
+	assert.True(certerr.IsCommitNotFoundErr(err))
 
 	// now add them all to the provider
-	for _, s := range seeds {
-		err = p.StoreSeed(s)
+	for _, fc := range commits {
+		err = p.StoreCommit(fc)
 		require.Nil(err)
 		// and make sure we can get it back
-		s2, err := p.GetByHash(s.Hash())
+		fc2, err := p.GetByHash(fc.ValidatorsHash())
 		assert.Nil(err)
-		assertSeedEqual(t, s, s2)
+		assertCommitsEqual(t, fc, fc2)
 		// by height as well
-		s2, err = p.GetByHeight(s.Height())
+		fc2, err = p.GetByHeight(fc.Height())
 		assert.Nil(err)
-		assertSeedEqual(t, s, s2)
+		assertCommitsEqual(t, fc, fc2)
 	}
 
 	// make sure we get the last hash if we overstep
-	seed, err = p.GetByHeight(5000)
+	fc, err = p.GetByHeight(5000)
 	if assert.Nil(err) {
-		assertSeedEqual(t, seeds[count-1], seed)
+		assertCommitsEqual(t, commits[count-1], fc)
 	}
 
 	// and middle ones as well
-	seed, err = p.GetByHeight(47)
+	fc, err = p.GetByHeight(47)
 	if assert.Nil(err) {
 		// we only step by 10, so 40 must be the one below this
-		assert.Equal(40, seed.Height())
+		assert.Equal(40, fc.Height())
 	}
 
 }
diff --git a/modules/ibc/test_helpers.go b/modules/ibc/test_helpers.go
index 6f0a9bda06..79960dadfb 100644
--- a/modules/ibc/test_helpers.go
+++ b/modules/ibc/test_helpers.go
@@ -32,8 +32,8 @@ func NewMockChain(chainID string, numKeys int) MockChain {
 
 // GetRegistrationTx returns a valid tx to register this chain
 func (m MockChain) GetRegistrationTx(h int) RegisterChainTx {
-	seed := genEmptySeed(m.keys, m.chainID, h, m.tree.Hash(), len(m.keys))
-	return RegisterChainTx{seed}
+	fc := genEmptyCommit(m.keys, m.chainID, h, m.tree.Hash(), len(m.keys))
+	return RegisterChainTx{fc}
 }
 
 // MakePostPacket commits the packet locally and returns the proof,
@@ -42,18 +42,17 @@ func (m MockChain) MakePostPacket(packet Packet, h int) (
 	PostPacketTx, UpdateChainTx) {
 
 	post := makePostPacket(m.tree, packet, m.chainID, h)
-	seed := genEmptySeed(m.keys, m.chainID, h+1, m.tree.Hash(), len(m.keys))
-	update := UpdateChainTx{seed}
+	fc := genEmptyCommit(m.keys, m.chainID, h+1, m.tree.Hash(), len(m.keys))
+	update := UpdateChainTx{fc}
 
 	return post, update
 }
 
-func genEmptySeed(keys certifiers.ValKeys, chain string, h int,
-	appHash []byte, count int) certifiers.Seed {
+func genEmptyCommit(keys certifiers.ValKeys, chain string, h int,
+	appHash []byte, count int) certifiers.FullCommit {
 
 	vals := keys.ToValidators(10, 0)
-	cp := keys.GenCheckpoint(chain, h, nil, vals, appHash, 0, count)
-	return certifiers.Seed{cp, vals}
+	return keys.GenFullCommit(chain, h, nil, vals, appHash, 0, count)
 }
 
 func makePostPacket(tree *iavl.Tree, packet Packet, fromID string, fromHeight int) PostPacketTx {
diff --git a/modules/ibc/tx.go b/modules/ibc/tx.go
index c2dc9ec835..eae5a38f94 100644
--- a/modules/ibc/tx.go
+++ b/modules/ibc/tx.go
@@ -32,17 +32,17 @@ func init() {
 
 // RegisterChainTx allows you to register a new chain on this blockchain
 type RegisterChainTx struct {
-	Seed certifiers.Seed `json:"seed"`
+	Commit certifiers.FullCommit `json:"seed"`
 }
 
 // ChainID helps get the chain this tx refers to
 func (r RegisterChainTx) ChainID() string {
-	return r.Seed.Header.ChainID
+	return r.Commit.Header.ChainID
 }
 
 // ValidateBasic makes sure this is consistent, without checking the sigs
 func (r RegisterChainTx) ValidateBasic() error {
-	err := r.Seed.ValidateBasic(r.ChainID())
+	err := r.Commit.ValidateBasic(r.ChainID())
 	if err != nil {
 		err = ErrInvalidCommit(err)
 	}
@@ -56,17 +56,17 @@ func (r RegisterChainTx) Wrap() sdk.Tx {
 
 // UpdateChainTx updates the state of this chain
 type UpdateChainTx struct {
-	Seed certifiers.Seed `json:"seed"`
+	Commit certifiers.FullCommit `json:"seed"`
 }
 
 // ChainID helps get the chain this tx refers to
 func (u UpdateChainTx) ChainID() string {
-	return u.Seed.Header.ChainID
+	return u.Commit.Header.ChainID
 }
 
 // ValidateBasic makes sure this is consistent, without checking the sigs
 func (u UpdateChainTx) ValidateBasic() error {
-	err := u.Seed.ValidateBasic(u.ChainID())
+	err := u.Commit.ValidateBasic(u.ChainID())
 	if err != nil {
 		err = ErrInvalidCommit(err)
 	}
diff --git a/modules/nonce/commands/query.go b/modules/nonce/commands/query.go
index 860f7b3aac..7021c8ca5a 100644
--- a/modules/nonce/commands/query.go
+++ b/modules/nonce/commands/query.go
@@ -7,9 +7,8 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
-	lc "github.com/tendermint/light-client"
-
 	sdk "github.com/cosmos/cosmos-sdk"
+	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/client/commands"
 	"github.com/cosmos/cosmos-sdk/client/commands/query"
 	"github.com/cosmos/cosmos-sdk/modules/nonce"
@@ -46,7 +45,7 @@ func doNonceQuery(signers []sdk.Actor) (sequence uint32, height uint64, err erro
 	key := stack.PrefixedKey(nonce.NameNonce, nonce.GetSeqKey(signers))
 	prove := !viper.GetBool(commands.FlagTrustNode)
 	height, err = query.GetParsed(key, &sequence, query.GetHeight(), prove)
-	if lc.IsNoDataErr(err) {
+	if client.IsNoDataErr(err) {
 		// no data, return sequence 0
 		return 0, 0, nil
 	}
diff --git a/modules/nonce/rest/handlers.go b/modules/nonce/rest/handlers.go
index f22601951a..05c0b2cd89 100644
--- a/modules/nonce/rest/handlers.go
+++ b/modules/nonce/rest/handlers.go
@@ -9,6 +9,7 @@ import (
 	"github.com/spf13/viper"
 
 	sdk "github.com/cosmos/cosmos-sdk"
+	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/client/commands"
 	"github.com/cosmos/cosmos-sdk/client/commands/query"
 	"github.com/cosmos/cosmos-sdk/errors"
@@ -16,7 +17,6 @@ import (
 	"github.com/cosmos/cosmos-sdk/modules/nonce"
 	"github.com/cosmos/cosmos-sdk/stack"
 	wire "github.com/tendermint/go-wire"
-	lightclient "github.com/tendermint/light-client"
 	"github.com/tendermint/tmlibs/common"
 )
 
@@ -48,7 +48,7 @@ func doQueryNonce(w http.ResponseWriter, r *http.Request) {
 
 	// query sequence number
 	data, height, err := query.Get(key, h, prove)
-	if lightclient.IsNoDataErr(err) {
+	if client.IsNoDataErr(err) {
 		err = fmt.Errorf("nonce empty for address: %q", signature)
 		common.WriteError(w, err)
 		return