diff --git a/go/extensions/codec.go b/go/extensions/codec.go
index 19d17820..acb04d00 100644
--- a/go/extensions/codec.go
+++ b/go/extensions/codec.go
@@ -34,5 +34,8 @@ func RegisterCodec(codec *amino.Codec) {
 	codec.RegisterConcrete(&MsgAddLiquidity{}, "irismod/coinswap/MsgAddLiquidity", nil)
 	codec.RegisterConcrete(&MsgRemoveLiquidity{}, "irismod/coinswap/MsgRemoveLiquidity", nil)
 	codec.RegisterConcrete(&CoinswapParams{}, "irismod/coinswap/Params", nil)
+	codec.RegisterConcrete(&MsgCreateHTLC{}, "irishub/htlc/MsgCreateHTLC", nil)
+	codec.RegisterConcrete(&MsgClaimHTLC{}, "irishub/htlc/MsgClaimHTLC", nil)
+	codec.RegisterConcrete(&MsgRefundHTLC{}, "irishub/htlc/MsgRefundHTLC", nil)
 
 }
diff --git a/go/extensions/htlc.go b/go/extensions/htlc.go
new file mode 100644
index 00000000..3ae9c331
--- /dev/null
+++ b/go/extensions/htlc.go
@@ -0,0 +1,26 @@
+package extensions
+
+import (
+	sdk "github.com/cosmos/amino-js/go/lib/cosmos/cosmos-sdk/types"
+)
+
+type MsgCreateHTLC struct {
+	Sender               sdk.AccAddress `json:"sender"`                  // the initiator address
+	To                   sdk.AccAddress `json:"to"`                      // the destination address
+	ReceiverOnOtherChain string         `json:"receiver_on_other_chain"` // the claim receiving address on the other chain
+	Amount               sdk.Coins      `json:"amount"`                  // the amount to be transferred
+	HashLock             []byte         `json:"hash_lock"`               // the hash lock generated from secret (and timestamp if provided)
+	Timestamp            uint64         `json:"timestamp"`               // if provided, used to generate the hash lock together with secret
+	TimeLock             uint64         `json:"time_lock"`               // the time span after which the HTLC will expire
+}
+
+type MsgClaimHTLC struct {
+	Sender   sdk.AccAddress `json:"sender"`    // the initiator address
+	HashLock []byte         `json:"hash_lock"` // the hash lock identifying the HTLC to be claimed
+	Secret   []byte         `json:"secret"`    // the secret with which to claim
+}
+
+type MsgRefundHTLC struct {
+	Sender   sdk.AccAddress `json:"sender"`    // the initiator address
+	HashLock []byte         `json:"hash_lock"` // the hash lock identifying the HTLC to be refunded
+}
\ No newline at end of file