diff --git a/PENDING.md b/PENDING.md
index 84dd4b95da83..92047d618bfd 100644
--- a/PENDING.md
+++ b/PENDING.md
@@ -25,7 +25,7 @@ BREAKING CHANGES
   *  Reintroduce OR semantics for tx fees
 
 * SDK
-  * \#2513 Tendermint updates are adjusted by 10^-6 relative to staking tokens, 
+  * \#2513 Tendermint updates are adjusted by 10^-6 relative to staking tokens,
   * [\#3487](https://github.com/cosmos/cosmos-sdk/pull/3487) Move HTTP/REST utilities out of client/utils into a new dedicated client/rest package.
   * [\#3490](https://github.com/cosmos/cosmos-sdk/issues/3490) ReadRESTReq() returns bool to avoid callers to write error responses twice.
   * [\#3502](https://github.com/cosmos/cosmos-sdk/pull/3502) Fixes issue when comparing genesis states
@@ -73,6 +73,7 @@ IMPROVEMENTS
   * [\#3423](https://github.com/cosmos/cosmos-sdk/issues/3423) Allow simulation
   (auto gas) to work with generate only.
   * [\#3514](https://github.com/cosmos/cosmos-sdk/pull/3514) REST server calls to keybase does not lock the underlying storage anymore.
+  * [\#3523](https://github.com/cosmos/cosmos-sdk/pull/3523) Added `/tx/encode` endpoint to serialize a JSON tx to base64-encoded Amino.
 
 * Gaia CLI  (`gaiacli`)
   * [\#3476](https://github.com/cosmos/cosmos-sdk/issues/3476) New `withdraw-all-rewards` command to withdraw all delegations rewards for delegators.
@@ -80,6 +81,7 @@ IMPROVEMENTS
   * [\#3518](https://github.com/cosmos/cosmos-sdk/issues/3518) Fix flow in
   `keys add` to show the mnemonic by default.
   * [\#3517](https://github.com/cosmos/cosmos-sdk/pull/3517) Increased test coverage
+  * [\#3523](https://github.com/cosmos/cosmos-sdk/pull/3523) Added `tx encode` command to serialize a JSON tx to base64-encoded Amino.
 
 * Gaia
   * [\#3418](https://github.com/cosmos/cosmos-sdk/issues/3418) Add vesting account
diff --git a/client/lcd/lcd_test.go b/client/lcd/lcd_test.go
index 7648d86a3012..fff8808dd741 100644
--- a/client/lcd/lcd_test.go
+++ b/client/lcd/lcd_test.go
@@ -1,6 +1,7 @@
 package lcd
 
 import (
+	"encoding/base64"
 	"encoding/hex"
 	"fmt"
 	"net/http"
@@ -423,6 +424,46 @@ func TestCoinSendGenerateSignAndBroadcast(t *testing.T) {
 	require.Equal(t, gasEstimate, resultTx.GasWanted)
 }
 
+func TestEncodeTx(t *testing.T) {
+	// Setup
+	kb, err := keys.NewKeyBaseFromDir(InitClientHome(t, ""))
+	require.NoError(t, err)
+	addr, seed := CreateAddr(t, name1, pw, kb)
+	cleanup, _, _, port := InitializeTestLCD(t, 1, []sdk.AccAddress{addr}, true)
+	defer cleanup()
+
+	// Make a transaction to test with
+	res, body, _ := doTransferWithGas(t, port, seed, name1, memo, "", addr, "2", 1, false, true, fees)
+	var tx auth.StdTx
+	cdc.UnmarshalJSON([]byte(body), &tx)
+
+	// Build the request
+	encodeReq := struct {
+		Tx auth.StdTx `json:"tx"`
+	}{Tx: tx}
+	encodedJSON, _ := cdc.MarshalJSON(encodeReq)
+	res, body = Request(t, port, "POST", "/tx/encode", encodedJSON)
+
+	// Make sure it came back ok, and that we can decode it back to the transaction
+	// 200 response
+	require.Equal(t, http.StatusOK, res.StatusCode, body)
+	encodeResp := struct {
+		Tx string `json:"tx"`
+	}{}
+
+	// No error decoding the JSON
+	require.Nil(t, cdc.UnmarshalJSON([]byte(body), &encodeResp))
+
+	// Check that the base64 decodes
+	decodedBytes, err := base64.StdEncoding.DecodeString(encodeResp.Tx)
+	require.Nil(t, err)
+
+	// Check that the transaction decodes as expected
+	var decodedTx auth.StdTx
+	require.Nil(t, cdc.UnmarshalBinaryLengthPrefixed(decodedBytes, &decodedTx))
+	require.Equal(t, memo, decodedTx.Memo)
+}
+
 func TestTxs(t *testing.T) {
 	kb, err := keys.NewKeyBaseFromDir(InitClientHome(t, ""))
 	require.NoError(t, err)
diff --git a/client/lcd/swagger-ui/swagger.yaml b/client/lcd/swagger-ui/swagger.yaml
index 38e9c1864399..82a6af083583 100644
--- a/client/lcd/swagger-ui/swagger.yaml
+++ b/client/lcd/swagger-ui/swagger.yaml
@@ -334,6 +334,39 @@ paths:
           description: The Tx was malformated
         500:
           description: Server internal error
+  /tx/encode:
+    post:
+      tags:
+        - ICS20
+      summary: Encode a transaction to wire format
+      description: Encode a transaction (signed or not) from JSON to base64-encoded Amino serialized bytes
+      consumes:
+        - application/json
+      produces:
+        - application/json
+      parameters:
+        - in: body
+          name: tx
+          description: The transaction to encode
+          required: true
+          schema:
+            type: object
+            properties:
+              tx:
+                $ref: "#/definitions/StdTx"
+      responses:
+        200:
+          description: Transaction was successfully decoded and re-encoded
+          schema:
+            type: object
+            properties:
+              tx:
+                type: string
+                example: The base64-encoded Amino-serialized bytes for the transaction
+        400:
+          description: The Tx was malformated
+        500:
+          description: Server internal error
   /bank/balances/{address}:
     get:
       summary: Get the account balances
diff --git a/cmd/gaia/cli_test/cli_test.go b/cmd/gaia/cli_test/cli_test.go
index fcea83893751..5df719f818ab 100644
--- a/cmd/gaia/cli_test/cli_test.go
+++ b/cmd/gaia/cli_test/cli_test.go
@@ -1,12 +1,14 @@
 package clitest
 
 import (
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
+	"strings"
 	"testing"
 	"time"
 
@@ -18,6 +20,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/cmd/gaia/app"
 	"github.com/cosmos/cosmos-sdk/tests"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/auth"
 	"github.com/cosmos/cosmos-sdk/x/gov"
 	"github.com/cosmos/cosmos-sdk/x/staking"
 )
@@ -587,7 +590,7 @@ func TestGaiaCLIValidateSignatures(t *testing.T) {
 	require.Empty(t, stderr)
 
 	// write  unsigned tx to file
-	unsignedTxFile := writeToNewTempFile(t, stdout)
+	unsignedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(unsignedTxFile.Name())
 
 	// validate we can successfully sign
@@ -600,7 +603,7 @@ func TestGaiaCLIValidateSignatures(t *testing.T) {
 	require.Equal(t, fooAddr.String(), stdTx.GetSigners()[0].String())
 
 	// write signed tx to file
-	signedTxFile := writeToNewTempFile(t, stdout)
+	signedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(signedTxFile.Name())
 
 	// validate signatures
@@ -610,7 +613,7 @@ func TestGaiaCLIValidateSignatures(t *testing.T) {
 	// modify the transaction
 	stdTx.Memo = "MODIFIED-ORIGINAL-TX-BAD"
 	bz := marshalStdTx(t, stdTx)
-	modSignedTxFile := writeToNewTempFile(t, string(bz))
+	modSignedTxFile := WriteToNewTempFile(t, string(bz))
 	defer os.Remove(modSignedTxFile.Name())
 
 	// validate signature validation failure due to different transaction sig bytes
@@ -659,7 +662,7 @@ func TestGaiaCLISendGenerateSignAndBroadcast(t *testing.T) {
 	require.Equal(t, len(msg.Msgs), 1)
 
 	// Write the output to disk
-	unsignedTxFile := writeToNewTempFile(t, stdout)
+	unsignedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(unsignedTxFile.Name())
 
 	// Test sign --validate-signatures
@@ -676,7 +679,7 @@ func TestGaiaCLISendGenerateSignAndBroadcast(t *testing.T) {
 	require.Equal(t, fooAddr.String(), msg.GetSigners()[0].String())
 
 	// Write the output to disk
-	signedTxFile := writeToNewTempFile(t, stdout)
+	signedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(signedTxFile.Name())
 
 	// Test sign --validate-signatures
@@ -732,7 +735,7 @@ func TestGaiaCLIMultisignInsufficientCosigners(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	unsignedTxFile := writeToNewTempFile(t, stdout)
+	unsignedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(unsignedTxFile.Name())
 
 	// Sign with foo's key
@@ -740,7 +743,7 @@ func TestGaiaCLIMultisignInsufficientCosigners(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	fooSignatureFile := writeToNewTempFile(t, stdout)
+	fooSignatureFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(fooSignatureFile.Name())
 
 	// Multisign, not enough signatures
@@ -748,7 +751,7 @@ func TestGaiaCLIMultisignInsufficientCosigners(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	signedTxFile := writeToNewTempFile(t, stdout)
+	signedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(signedTxFile.Name())
 
 	// Validate the multisignature
@@ -760,6 +763,42 @@ func TestGaiaCLIMultisignInsufficientCosigners(t *testing.T) {
 	require.False(t, success)
 }
 
+func TestGaiaCLIEncode(t *testing.T) {
+	t.Parallel()
+	f := InitFixtures(t)
+
+	// start gaiad server
+	proc := f.GDStart()
+	defer proc.Stop(false)
+
+	cdc := app.MakeCodec()
+
+	// Build a testing transaction and write it to disk
+	barAddr := f.KeyAddress(keyBar)
+	sendTokens := staking.TokensFromTendermintPower(10)
+	success, stdout, stderr := f.TxSend(keyFoo, barAddr, sdk.NewCoin(denom, sendTokens), "--generate-only", "--memo", "deadbeef")
+	require.True(t, success)
+	require.Empty(t, stderr)
+
+	// Write it to disk
+	jsonTxFile := WriteToNewTempFile(t, stdout)
+	defer os.Remove(jsonTxFile.Name())
+
+	// Run the encode command, and trim the extras from the stdout capture
+	success, base64Encoded, _ := f.TxEncode(jsonTxFile.Name())
+	require.True(t, success)
+	trimmedBase64 := strings.Trim(base64Encoded, "\"\n")
+
+	// Decode the base64
+	decodedBytes, err := base64.StdEncoding.DecodeString(trimmedBase64)
+	require.Nil(t, err)
+
+	// Check that the transaction decodes as epxceted
+	var decodedTx auth.StdTx
+	require.Nil(t, cdc.UnmarshalBinaryLengthPrefixed(decodedBytes, &decodedTx))
+	require.Equal(t, "deadbeef", decodedTx.Memo)
+}
+
 func TestGaiaCLIMultisignSortSignatures(t *testing.T) {
 	t.Parallel()
 	f := InitFixtures(t)
@@ -785,7 +824,7 @@ func TestGaiaCLIMultisignSortSignatures(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	unsignedTxFile := writeToNewTempFile(t, stdout)
+	unsignedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(unsignedTxFile.Name())
 
 	// Sign with foo's key
@@ -793,7 +832,7 @@ func TestGaiaCLIMultisignSortSignatures(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	fooSignatureFile := writeToNewTempFile(t, stdout)
+	fooSignatureFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(fooSignatureFile.Name())
 
 	// Sign with baz's key
@@ -801,7 +840,7 @@ func TestGaiaCLIMultisignSortSignatures(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	bazSignatureFile := writeToNewTempFile(t, stdout)
+	bazSignatureFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(bazSignatureFile.Name())
 
 	// Multisign, keys in different order
@@ -810,7 +849,7 @@ func TestGaiaCLIMultisignSortSignatures(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	signedTxFile := writeToNewTempFile(t, stdout)
+	signedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(signedTxFile.Name())
 
 	// Validate the multisignature
@@ -848,7 +887,7 @@ func TestGaiaCLIMultisign(t *testing.T) {
 	require.Empty(t, stderr)
 
 	// Write the output to disk
-	unsignedTxFile := writeToNewTempFile(t, stdout)
+	unsignedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(unsignedTxFile.Name())
 
 	// Sign with foo's key
@@ -856,7 +895,7 @@ func TestGaiaCLIMultisign(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	fooSignatureFile := writeToNewTempFile(t, stdout)
+	fooSignatureFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(fooSignatureFile.Name())
 
 	// Sign with bar's key
@@ -864,7 +903,7 @@ func TestGaiaCLIMultisign(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	barSignatureFile := writeToNewTempFile(t, stdout)
+	barSignatureFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(barSignatureFile.Name())
 
 	// Multisign
@@ -873,7 +912,7 @@ func TestGaiaCLIMultisign(t *testing.T) {
 	require.True(t, success)
 
 	// Write the output to disk
-	signedTxFile := writeToNewTempFile(t, stdout)
+	signedTxFile := WriteToNewTempFile(t, stdout)
 	defer os.Remove(signedTxFile.Name())
 
 	// Validate the multisignature
diff --git a/cmd/gaia/cli_test/test_helpers.go b/cmd/gaia/cli_test/test_helpers.go
index d598d64efa70..899a1db0e5a9 100644
--- a/cmd/gaia/cli_test/test_helpers.go
+++ b/cmd/gaia/cli_test/test_helpers.go
@@ -294,12 +294,18 @@ func (f *Fixtures) TxSign(signer, fileName string, flags ...string) (bool, strin
 	return executeWriteRetStdStreams(f.T, addFlags(cmd, flags), app.DefaultKeyPass)
 }
 
-// TxBroadcast is gaiacli tx sign
+// TxBroadcast is gaiacli tx broadcast
 func (f *Fixtures) TxBroadcast(fileName string, flags ...string) (bool, string, string) {
 	cmd := fmt.Sprintf("gaiacli tx broadcast %v %v", f.Flags(), fileName)
 	return executeWriteRetStdStreams(f.T, addFlags(cmd, flags), app.DefaultKeyPass)
 }
 
+// TxEncode is gaiacli tx encode
+func (f *Fixtures) TxEncode(fileName string, flags ...string) (bool, string, string) {
+	cmd := fmt.Sprintf("gaiacli tx encode %v %v", f.Flags(), fileName)
+	return executeWriteRetStdStreams(f.T, addFlags(cmd, flags), app.DefaultKeyPass)
+}
+
 // TxMultisign is gaiacli tx multisign
 func (f *Fixtures) TxMultisign(fileName, name string, signaturesFiles []string,
 	flags ...string) (bool, string, string) {
@@ -640,7 +646,8 @@ func queryTags(tags []string) (out string) {
 	return strings.TrimSuffix(out, "&")
 }
 
-func writeToNewTempFile(t *testing.T, s string) *os.File {
+// Write the given string to a new temporary file
+func WriteToNewTempFile(t *testing.T, s string) *os.File {
 	fp, err := ioutil.TempFile(os.TempDir(), "cosmos_cli_test_")
 	require.Nil(t, err)
 	_, err = fp.WriteString(s)
diff --git a/cmd/gaia/cmd/gaiacli/main.go b/cmd/gaia/cmd/gaiacli/main.go
index f9cb8517342d..a5939116ffd6 100644
--- a/cmd/gaia/cmd/gaiacli/main.go
+++ b/cmd/gaia/cmd/gaiacli/main.go
@@ -141,7 +141,8 @@ func txCmd(cdc *amino.Codec, mc []sdk.ModuleClients) *cobra.Command {
 		client.LineBreak,
 		authcmd.GetSignCommand(cdc),
 		authcmd.GetMultiSignCommand(cdc),
-		bankcmd.GetBroadcastCommand(cdc),
+		authcmd.GetBroadcastCommand(cdc),
+		authcmd.GetEncodeCommand(cdc),
 		client.LineBreak,
 	)
 
diff --git a/x/bank/client/cli/broadcast.go b/x/auth/client/cli/broadcast.go
similarity index 71%
rename from x/bank/client/cli/broadcast.go
rename to x/auth/client/cli/broadcast.go
index 09ba88d14306..8dc1992b597a 100644
--- a/x/bank/client/cli/broadcast.go
+++ b/x/auth/client/cli/broadcast.go
@@ -1,8 +1,6 @@
 package cli
 
 import (
-	"io/ioutil"
-	"os"
 	"strings"
 
 	"github.com/spf13/cobra"
@@ -10,7 +8,7 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/client/context"
-	"github.com/cosmos/cosmos-sdk/x/auth"
+	authclient "github.com/cosmos/cosmos-sdk/x/auth/client"
 )
 
 // GetSignCommand returns the sign command
@@ -27,7 +25,7 @@ $ gaiacli tx broadcast ./mytxn.json
 		Args: cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) (err error) {
 			cliCtx := context.NewCLIContext().WithCodec(codec)
-			stdTx, err := readAndUnmarshalStdTx(cliCtx.Codec, args[0])
+			stdTx, err := authclient.ReadStdTxFromFile(cliCtx.Codec, args[0])
 			if err != nil {
 				return
 			}
@@ -45,19 +43,3 @@ $ gaiacli tx broadcast ./mytxn.json
 
 	return client.PostCommands(cmd)[0]
 }
-
-func readAndUnmarshalStdTx(cdc *amino.Codec, filename string) (stdTx auth.StdTx, err error) {
-	var bytes []byte
-	if filename == "-" {
-		bytes, err = ioutil.ReadAll(os.Stdin)
-	} else {
-		bytes, err = ioutil.ReadFile(filename)
-	}
-	if err != nil {
-		return
-	}
-	if err = cdc.UnmarshalJSON(bytes, &stdTx); err != nil {
-		return
-	}
-	return
-}
diff --git a/x/auth/client/cli/encode.go b/x/auth/client/cli/encode.go
new file mode 100644
index 000000000000..07179155152f
--- /dev/null
+++ b/x/auth/client/cli/encode.go
@@ -0,0 +1,55 @@
+package cli
+
+import (
+	"encoding/base64"
+
+	"github.com/spf13/cobra"
+	amino "github.com/tendermint/go-amino"
+
+	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/cosmos/cosmos-sdk/client/context"
+	authclient "github.com/cosmos/cosmos-sdk/x/auth/client"
+)
+
+// PrintOutput requires a Stringer, so we wrap string
+type encodeResp string
+
+func (e encodeResp) String() string {
+	return string(e)
+}
+
+// GetEncodeCommand returns the encode command to take a JSONified transaction and turn it into
+// Amino-serialized bytes
+func GetEncodeCommand(codec *amino.Codec) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "encode [file]",
+		Short: "encode transactions generated offline",
+		Long: `Encode transactions created with the --generate-only flag and signed with the sign command.
+Read a transaction from <file>, serialize it to the Amino wire protocol, and output it as base64.
+If you supply a dash (-) argument in place of an input filename, the command reads from standard input.`,
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) (err error) {
+			cliCtx := context.NewCLIContext().WithCodec(codec)
+
+			stdTx, err := authclient.ReadStdTxFromFile(cliCtx.Codec, args[0])
+			if err != nil {
+				return
+			}
+
+			txBytes, err := cliCtx.Codec.MarshalBinaryLengthPrefixed(stdTx)
+			if err != nil {
+				return err
+			}
+
+			// Encode the bytes to base64
+			txBytesBase64 := base64.StdEncoding.EncodeToString(txBytes)
+
+			// Write it back
+			response := encodeResp(txBytesBase64)
+			cliCtx.PrintOutput(response)
+			return nil
+		},
+	}
+
+	return client.PostCommands(cmd)[0]
+}
diff --git a/x/auth/client/cli/multisign.go b/x/auth/client/cli/multisign.go
index 5101dda1144b..fdcd1d14247a 100644
--- a/x/auth/client/cli/multisign.go
+++ b/x/auth/client/cli/multisign.go
@@ -16,6 +16,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/client/keys"
 	crkeys "github.com/cosmos/cosmos-sdk/crypto/keys"
 	"github.com/cosmos/cosmos-sdk/x/auth"
+	authclient "github.com/cosmos/cosmos-sdk/x/auth/client"
 	authtxb "github.com/cosmos/cosmos-sdk/x/auth/client/txbuilder"
 )
 
@@ -51,7 +52,7 @@ recommended to set such parameters manually.
 
 func makeMultiSignCmd(cdc *amino.Codec) func(cmd *cobra.Command, args []string) error {
 	return func(cmd *cobra.Command, args []string) (err error) {
-		stdTx, err := readAndUnmarshalStdTx(cdc, args[0])
+		stdTx, err := authclient.ReadStdTxFromFile(cdc, args[0])
 		if err != nil {
 			return
 		}
diff --git a/x/auth/client/cli/sign.go b/x/auth/client/cli/sign.go
index 171692ba565d..371abd84bfb4 100644
--- a/x/auth/client/cli/sign.go
+++ b/x/auth/client/cli/sign.go
@@ -3,7 +3,6 @@ package cli
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 
 	"github.com/spf13/cobra"
@@ -15,6 +14,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/client/utils"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/auth"
+	authclient "github.com/cosmos/cosmos-sdk/x/auth/client"
 	authtxb "github.com/cosmos/cosmos-sdk/x/auth/client/txbuilder"
 )
 
@@ -75,7 +75,7 @@ be generated via the 'multisign' command.
 
 func makeSignCmd(cdc *amino.Codec) func(cmd *cobra.Command, args []string) error {
 	return func(cmd *cobra.Command, args []string) (err error) {
-		stdTx, err := readAndUnmarshalStdTx(cdc, args[0])
+		stdTx, err := authclient.ReadStdTxFromFile(cdc, args[0])
 		if err != nil {
 			return
 		}
@@ -222,14 +222,3 @@ func printAndValidateSigs(
 	fmt.Println("")
 	return success
 }
-
-func readAndUnmarshalStdTx(cdc *amino.Codec, filename string) (stdTx auth.StdTx, err error) {
-	var bytes []byte
-	if bytes, err = ioutil.ReadFile(filename); err != nil {
-		return
-	}
-	if err = cdc.UnmarshalJSON(bytes, &stdTx); err != nil {
-		return
-	}
-	return
-}
diff --git a/x/bank/client/rest/broadcast.go b/x/auth/client/rest/broadcast.go
similarity index 95%
rename from x/bank/client/rest/broadcast.go
rename to x/auth/client/rest/broadcast.go
index 1d40c2820e23..3d923589a212 100644
--- a/x/bank/client/rest/broadcast.go
+++ b/x/auth/client/rest/broadcast.go
@@ -38,7 +38,7 @@ func BroadcastTxRequestHandlerFn(cdc *codec.Codec, cliCtx context.CLIContext) ht
 	}
 }
 
-func unmarshalBodyOrReturnBadRequest(cliCtx context.CLIContext, w http.ResponseWriter, r *http.Request, m *broadcastBody) bool {
+func unmarshalBodyOrReturnBadRequest(cliCtx context.CLIContext, w http.ResponseWriter, r *http.Request, m interface{}) bool {
 	body, err := ioutil.ReadAll(r.Body)
 	if err != nil {
 		rest.WriteErrorResponse(w, http.StatusBadRequest, err.Error())
diff --git a/x/auth/client/rest/encode.go b/x/auth/client/rest/encode.go
new file mode 100644
index 000000000000..bac646038bcc
--- /dev/null
+++ b/x/auth/client/rest/encode.go
@@ -0,0 +1,46 @@
+package rest
+
+import (
+	"encoding/base64"
+	"net/http"
+
+	"github.com/cosmos/cosmos-sdk/client/context"
+	"github.com/cosmos/cosmos-sdk/client/rest"
+	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/x/auth"
+)
+
+type encodeReq struct {
+	Tx auth.StdTx `json:"tx"`
+}
+
+type encodeResp struct {
+	Tx string `json:"tx"`
+}
+
+// EncodeTxRequestHandlerFn returns the encode tx REST handler.  In particular, it takes a
+// json-formatted transaction, encodes it to the Amino wire protocol, and responds with
+// base64-encoded bytes
+func EncodeTxRequestHandlerFn(cdc *codec.Codec, cliCtx context.CLIContext) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		var m encodeReq
+		// Decode the transaction from JSON
+		if ok := unmarshalBodyOrReturnBadRequest(cliCtx, w, r, &m); !ok {
+			return
+		}
+
+		// Re-encode it to the wire protocol
+		txBytes, err := cliCtx.Codec.MarshalBinaryLengthPrefixed(m.Tx)
+		if err != nil {
+			rest.WriteErrorResponse(w, http.StatusInternalServerError, err.Error())
+			return
+		}
+
+		// Encode the bytes to base64
+		txBytesBase64 := base64.StdEncoding.EncodeToString(txBytes)
+
+		// Write it back
+		response := encodeResp{Tx: txBytesBase64}
+		rest.PostProcessResponse(w, cdc, response, cliCtx.Indent)
+	}
+}
diff --git a/x/auth/client/rest/query.go b/x/auth/client/rest/query.go
index 50ae9e23418d..97810cecf1eb 100644
--- a/x/auth/client/rest/query.go
+++ b/x/auth/client/rest/query.go
@@ -22,6 +22,14 @@ func RegisterRoutes(cliCtx context.CLIContext, r *mux.Router, cdc *codec.Codec,
 		"/bank/balances/{address}",
 		QueryBalancesRequestHandlerFn(storeName, cdc, context.GetAccountDecoder(cdc), cliCtx),
 	).Methods("GET")
+	r.HandleFunc(
+		"/tx/broadcast",
+		BroadcastTxRequestHandlerFn(cdc, cliCtx),
+	).Methods("POST")
+	r.HandleFunc(
+		"/tx/encode",
+		EncodeTxRequestHandlerFn(cdc, cliCtx),
+	).Methods("POST")
 	r.HandleFunc(
 		"/tx/sign",
 		SignTxRequestHandlerFn(cdc, cliCtx),
diff --git a/x/auth/client/util.go b/x/auth/client/util.go
new file mode 100644
index 000000000000..94eb480d6ab5
--- /dev/null
+++ b/x/auth/client/util.go
@@ -0,0 +1,27 @@
+package client
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/tendermint/go-amino"
+
+	"github.com/cosmos/cosmos-sdk/x/auth"
+)
+
+// Read and decode a StdTx from the given filename.  Can pass "-" to read from stdin.
+func ReadStdTxFromFile(cdc *amino.Codec, filename string) (stdTx auth.StdTx, err error) {
+	var bytes []byte
+	if filename == "-" {
+		bytes, err = ioutil.ReadAll(os.Stdin)
+	} else {
+		bytes, err = ioutil.ReadFile(filename)
+	}
+	if err != nil {
+		return
+	}
+	if err = cdc.UnmarshalJSON(bytes, &stdTx); err != nil {
+		return
+	}
+	return
+}
diff --git a/x/auth/client/util_test.go b/x/auth/client/util_test.go
new file mode 100644
index 000000000000..409219cd7269
--- /dev/null
+++ b/x/auth/client/util_test.go
@@ -0,0 +1,32 @@
+package client
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/cosmos/cosmos-sdk/cmd/gaia/cli_test"
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/auth"
+)
+
+func TestReadStdTxFromFile(t *testing.T) {
+	cdc := codec.New()
+	sdk.RegisterCodec(cdc)
+
+	// Build a test transaction
+	fee := auth.NewStdFee(50000, sdk.Coins{sdk.NewInt64Coin("atom", 150)})
+	stdTx := auth.NewStdTx([]sdk.Msg{}, fee, []auth.StdSignature{}, "foomemo")
+
+	// Write it to the file
+	encodedTx, _ := cdc.MarshalJSON(stdTx)
+	jsonTxFile := clitest.WriteToNewTempFile(t, string(encodedTx))
+	defer os.Remove(jsonTxFile.Name())
+
+	// Read it back
+	decodedTx, err := ReadStdTxFromFile(cdc, jsonTxFile.Name())
+	require.Nil(t, err)
+	require.Equal(t, decodedTx.Memo, "foomemo")
+}
diff --git a/x/bank/client/rest/sendtx.go b/x/bank/client/rest/sendtx.go
index 2e7cbbdd972d..e602539dccdc 100644
--- a/x/bank/client/rest/sendtx.go
+++ b/x/bank/client/rest/sendtx.go
@@ -17,7 +17,6 @@ import (
 // RegisterRoutes - Central function to define routes that get registered by the main application
 func RegisterRoutes(cliCtx context.CLIContext, r *mux.Router, cdc *codec.Codec, kb keys.Keybase) {
 	r.HandleFunc("/bank/accounts/{address}/transfers", SendRequestHandlerFn(cdc, kb, cliCtx)).Methods("POST")
-	r.HandleFunc("/tx/broadcast", BroadcastTxRequestHandlerFn(cdc, cliCtx)).Methods("POST")
 }
 
 type sendReq struct {