diff --git a/docs/MIGRATING.md b/docs/MIGRATING.md
index 7c6a6be34..95d4bcdec 100644
--- a/docs/MIGRATING.md
+++ b/docs/MIGRATING.md
@@ -33,6 +33,15 @@
   whether the given string is a valid address. This was previously done
   internally using separate calls to `CanonicalizeAddress` and `HumanizeAddress`
   but can be done more efficiently using a single call.
+- The IBC `TransferMsg` now includes an optional `Memo` field.
+- `SubMsgResponse` now has an additional `MsgResponses` field, mirroring the
+  Cosmos SDK
+- The types `Events`, `EventAttributes`, `Delegations`, `IBCChannels`,
+  `Validators`, `MsgResponses` and `Coins` were replaced with a generic
+  `Array[C]` type. This new type is a wrapper around a `[]C`. One difference to
+  the old behavior is that the new type will unmarshal to an empty slice when
+  the JSON value is `null` or `[]`. Previously, both cases resulted in a `nil`
+  value.
 
 ## Renamings
 
diff --git a/ibc_test.go b/ibc_test.go
index fb8a76a5b..4212bc19e 100644
--- a/ibc_test.go
+++ b/ibc_test.go
@@ -96,7 +96,7 @@ func TestIBCHandshake(t *testing.T) {
 	// instantiate it with this store
 	store := api.NewLookup(gasMeter1)
 	goapi := api.NewMockAPI()
-	balance := types.Coins{}
+	balance := types.Array[types.Coin]{}
 	querier := api.DefaultQuerier(api.MOCK_CONTRACT_ADDR, balance)
 
 	// instantiate
@@ -169,7 +169,7 @@ func TestIBCPacketDispatch(t *testing.T) {
 	// instantiate it with this store
 	store := api.NewLookup(gasMeter1)
 	goapi := api.NewMockAPI()
-	balance := types.Coins{}
+	balance := types.Array[types.Coin]{}
 	querier := api.DefaultQuerier(api.MOCK_CONTRACT_ADDR, balance)
 
 	// instantiate
@@ -210,9 +210,9 @@ func TestIBCPacketDispatch(t *testing.T) {
 		ID: id,
 		Result: types.SubMsgResult{
 			Ok: &types.SubMsgResponse{
-				Events: types.Events{{
+				Events: types.Array[types.Event]{{
 					Type: "instantiate",
-					Attributes: types.EventAttributes{
+					Attributes: types.Array[types.EventAttribute]{
 						{
 							Key:   "_contract_address",
 							Value: REFLECT_ADDR,
@@ -249,7 +249,7 @@ func TestIBCPacketDispatch(t *testing.T) {
 			Msgs: []types.CosmosMsg{{
 				Bank: &types.BankMsg{Send: &types.SendMsg{
 					ToAddress: "my-friend",
-					Amount:    types.Coins{types.NewCoin(12345678, "uatom")},
+					Amount:    types.Array[types.Coin]{types.NewCoin(12345678, "uatom")},
 				}},
 			}},
 		},
diff --git a/internal/api/api_test.go b/internal/api/api_test.go
index dc0921b4c..cc3f25e5b 100644
--- a/internal/api/api_test.go
+++ b/internal/api/api_test.go
@@ -24,7 +24,7 @@ func TestValidateAddressFailure(t *testing.T) {
 	// instantiate it with this store
 	store := NewLookup(gasMeter)
 	api := NewMockAPI()
-	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Coins{types.NewCoin(100, "ATOM")})
+	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Array[types.Coin]{types.NewCoin(100, "ATOM")})
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
 
diff --git a/internal/api/iterator_test.go b/internal/api/iterator_test.go
index 3585460fd..bf7a34635 100644
--- a/internal/api/iterator_test.go
+++ b/internal/api/iterator_test.go
@@ -31,7 +31,7 @@ func setupQueueContractWithData(t *testing.T, cache Cache, values ...int) queueD
 	// instantiate it with this store
 	store := NewLookup(gasMeter1)
 	api := NewMockAPI()
-	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Coins{types.NewCoin(100, "ATOM")})
+	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Array[types.Coin]{types.NewCoin(100, "ATOM")})
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
 	msg := []byte(`{}`)
diff --git a/internal/api/lib_test.go b/internal/api/lib_test.go
index 5fe32790f..3d8725128 100644
--- a/internal/api/lib_test.go
+++ b/internal/api/lib_test.go
@@ -292,7 +292,7 @@ func TestGetMetrics(t *testing.T) {
 	igasMeter := types.GasMeter(gasMeter)
 	store := NewLookup(gasMeter)
 	api := NewMockAPI()
-	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Coins{types.NewCoin(100, "ATOM")})
+	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Array[types.Coin]{types.NewCoin(100, "ATOM")})
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
 	msg1 := []byte(`{"verifier": "fred", "beneficiary": "bob"}`)
@@ -397,7 +397,7 @@ func TestInstantiate(t *testing.T) {
 	// instantiate it with this store
 	store := NewLookup(gasMeter)
 	api := NewMockAPI()
-	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Coins{types.NewCoin(100, "ATOM")})
+	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Array[types.Coin]{types.NewCoin(100, "ATOM")})
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
 	msg := []byte(`{"verifier": "fred", "beneficiary": "bob"}`)
@@ -424,7 +424,7 @@ func TestExecute(t *testing.T) {
 	// instantiate it with this store
 	store := NewLookup(gasMeter1)
 	api := NewMockAPI()
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, balance)
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
@@ -489,7 +489,7 @@ func TestExecutePanic(t *testing.T) {
 	// instantiate it with this store
 	store := NewLookup(gasMeter1)
 	api := NewMockAPI()
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, balance)
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
@@ -518,7 +518,7 @@ func TestExecuteUnreachable(t *testing.T) {
 	// instantiate it with this store
 	store := NewLookup(gasMeter1)
 	api := NewMockAPI()
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, balance)
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
@@ -702,7 +702,7 @@ func TestExecuteUserErrorsInApiCalls(t *testing.T) {
 	igasMeter1 := types.GasMeter(gasMeter1)
 	// instantiate it with this store
 	store := NewLookup(gasMeter1)
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, balance)
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
@@ -733,7 +733,7 @@ func TestMigrate(t *testing.T) {
 	// instantiate it with this store
 	store := NewLookup(gasMeter)
 	api := NewMockAPI()
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, balance)
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
@@ -778,7 +778,7 @@ func TestMultipleInstances(t *testing.T) {
 	igasMeter1 := types.GasMeter(gasMeter1)
 	store1 := NewLookup(gasMeter1)
 	api := NewMockAPI()
-	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Coins{types.NewCoin(100, "ATOM")})
+	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Array[types.Coin]{types.NewCoin(100, "ATOM")})
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "regen")
 	msg := []byte(`{"verifier": "fred", "beneficiary": "bob"}`)
@@ -832,7 +832,7 @@ func TestSudo(t *testing.T) {
 	// instantiate it with this store
 	store := NewLookup(gasMeter1)
 	api := NewMockAPI()
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, balance)
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
@@ -862,7 +862,7 @@ func TestSudo(t *testing.T) {
 	require.NotNil(t, dispatch.Bank.Send, "%#v", dispatch)
 	send := dispatch.Bank.Send
 	assert.Equal(t, "community-pool", send.ToAddress)
-	expectedPayout := types.Coins{types.NewCoin(700, "gold")}
+	expectedPayout := types.Array[types.Coin]{types.NewCoin(700, "gold")}
 	assert.Equal(t, expectedPayout, send.Amount)
 }
 
@@ -891,7 +891,7 @@ func TestDispatchSubmessage(t *testing.T) {
 		ID: id,
 		Msg: types.CosmosMsg{Bank: &types.BankMsg{Send: &types.SendMsg{
 			ToAddress: "friend",
-			Amount:    types.Coins{types.NewCoin(1, "token")},
+			Amount:    types.Array[types.Coin]{types.NewCoin(1, "token")},
 		}}},
 		ReplyOn: types.ReplyAlways,
 	}
@@ -940,9 +940,9 @@ func TestReplyAndQuery(t *testing.T) {
 
 	var id uint64 = 1234
 	data := []byte("foobar")
-	events := types.Events{{
+	events := types.Array[types.Event]{{
 		Type: "message",
-		Attributes: types.EventAttributes{{
+		Attributes: types.Array[types.EventAttribute]{{
 			Key:   "signer",
 			Value: "caller-addr",
 		}},
@@ -1067,7 +1067,7 @@ func TestQuery(t *testing.T) {
 	igasMeter1 := types.GasMeter(gasMeter1)
 	store := NewLookup(gasMeter1)
 	api := NewMockAPI()
-	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Coins{types.NewCoin(100, "ATOM")})
+	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, types.Array[types.Coin]{types.NewCoin(100, "ATOM")})
 	env := MockEnvBin(t)
 	info := MockInfoBin(t, "creator")
 	msg := []byte(`{"verifier": "fred", "beneficiary": "bob"}`)
@@ -1110,7 +1110,7 @@ func TestHackatomQuerier(t *testing.T) {
 	igasMeter := types.GasMeter(gasMeter)
 	store := NewLookup(gasMeter)
 	api := NewMockAPI()
-	initBalance := types.Coins{types.NewCoin(1234, "ATOM"), types.NewCoin(65432, "ETH")}
+	initBalance := types.Array[types.Coin]{types.NewCoin(1234, "ATOM"), types.NewCoin(65432, "ETH")}
 	querier := DefaultQuerier("foobar", initBalance)
 
 	// make a valid query to the other address
@@ -1153,7 +1153,7 @@ func TestCustomReflectQuerier(t *testing.T) {
 	igasMeter := types.GasMeter(gasMeter)
 	store := NewLookup(gasMeter)
 	api := NewMockAPI()
-	initBalance := types.Coins{types.NewCoin(1234, "ATOM")}
+	initBalance := types.Array[types.Coin]{types.NewCoin(1234, "ATOM")}
 	querier := DefaultQuerier(MOCK_CONTRACT_ADDR, initBalance)
 	// we need this to handle the custom requests from the reflect contract
 	innerQuerier := querier.(*MockQuerier)
diff --git a/internal/api/mocks.go b/internal/api/mocks.go
index dbc5eecc4..84fcd7e65 100644
--- a/internal/api/mocks.go
+++ b/internal/api/mocks.go
@@ -412,8 +412,8 @@ type MockQuerier struct {
 
 var _ types.Querier = &MockQuerier{}
 
-func DefaultQuerier(contractAddr string, coins types.Coins) types.Querier {
-	balances := map[string]types.Coins{
+func DefaultQuerier(contractAddr string, coins types.Array[types.Coin]) types.Querier {
+	balances := map[string]types.Array[types.Coin]{
 		contractAddr: coins,
 	}
 	return &MockQuerier{
@@ -449,11 +449,11 @@ func (q MockQuerier) GasConsumed() uint64 {
 }
 
 type BankQuerier struct {
-	Balances map[string]types.Coins
+	Balances map[string]types.Array[types.Coin]
 }
 
-func NewBankQuerier(balances map[string]types.Coins) BankQuerier {
-	bal := make(map[string]types.Coins, len(balances))
+func NewBankQuerier(balances map[string]types.Array[types.Coin]) BankQuerier {
+	bal := make(map[string]types.Array[types.Coin], len(balances))
 	for k, v := range balances {
 		dst := make([]types.Coin, len(v))
 		copy(dst, v)
@@ -540,7 +540,7 @@ func (q ReflectCustom) Query(request json.RawMessage) ([]byte, error) {
 
 func TestBankQuerierAllBalances(t *testing.T) {
 	addr := "foobar"
-	balance := types.Coins{types.NewCoin(12345678, "ATOM"), types.NewCoin(54321, "ETH")}
+	balance := types.Array[types.Coin]{types.NewCoin(12345678, "ATOM"), types.NewCoin(54321, "ETH")}
 	q := DefaultQuerier(addr, balance)
 
 	// query existing account
@@ -576,7 +576,7 @@ func TestBankQuerierAllBalances(t *testing.T) {
 
 func TestBankQuerierBalance(t *testing.T) {
 	addr := "foobar"
-	balance := types.Coins{types.NewCoin(12345678, "ATOM"), types.NewCoin(54321, "ETH")}
+	balance := types.Array[types.Coin]{types.NewCoin(12345678, "ATOM"), types.NewCoin(54321, "ETH")}
 	q := DefaultQuerier(addr, balance)
 
 	// query existing account with matching denom
diff --git a/lib_test.go b/lib_test.go
index 57572adcf..4d7a4c957 100644
--- a/lib_test.go
+++ b/lib_test.go
@@ -139,7 +139,7 @@ func TestHappyPath(t *testing.T) {
 	// instantiate it with this store
 	store := api.NewLookup(gasMeter1)
 	goapi := api.NewMockAPI()
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := api.DefaultQuerier(api.MOCK_CONTRACT_ADDR, balance)
 
 	// instantiate
@@ -184,7 +184,7 @@ func TestEnv(t *testing.T) {
 	// instantiate it with this store
 	store := api.NewLookup(gasMeter1)
 	goapi := api.NewMockAPI()
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := api.DefaultQuerier(api.MOCK_CONTRACT_ADDR, balance)
 
 	// instantiate
@@ -264,7 +264,7 @@ func TestGetMetrics(t *testing.T) {
 	// instantiate it with this store
 	store := api.NewLookup(gasMeter1)
 	goapi := api.NewMockAPI()
-	balance := types.Coins{types.NewCoin(250, "ATOM")}
+	balance := types.Array[types.Coin]{types.NewCoin(250, "ATOM")}
 	querier := api.DefaultQuerier(api.MOCK_CONTRACT_ADDR, balance)
 
 	env := api.MockEnv()
diff --git a/types/env.go b/types/env.go
index 8ad0bbbe1..b175ab1e6 100644
--- a/types/env.go
+++ b/types/env.go
@@ -39,5 +39,5 @@ type MessageInfo struct {
 	// Bech32 encoded sdk.AccAddress executing the contract
 	Sender HumanAddress `json:"sender"`
 	// Amount of funds send to the contract along with this message
-	Funds Coins `json:"funds"`
+	Funds Array[Coin] `json:"funds"`
 }
diff --git a/types/env_test.go b/types/env_test.go
index 2cc092cab..4bae5038a 100644
--- a/types/env_test.go
+++ b/types/env_test.go
@@ -34,10 +34,14 @@ func TestMessageInfoHandlesMissingCoins(t *testing.T) {
 	require.NoError(t, err)
 
 	// we can unmarshal it properly into struct
+	expected := MessageInfo{
+		Sender: "baz",
+		Funds:  []Coin{},
+	}
 	var recover MessageInfo
 	err = json.Unmarshal(bz, &recover)
 	require.NoError(t, err)
-	assert.Equal(t, info, recover)
+	assert.Equal(t, expected, recover)
 
 	// make sure "funds":[] is in JSON
 	var raw map[string]json.RawMessage
diff --git a/types/ibc_test.go b/types/ibc_test.go
index 73da7584b..8c17b558d 100644
--- a/types/ibc_test.go
+++ b/types/ibc_test.go
@@ -92,3 +92,28 @@ func TestIbcTimeoutDeserialization(t *testing.T) {
 		Timestamp: 0,
 	}, timeout4)
 }
+
+func TestIbcReceiveResponseDeserialization(t *testing.T) {
+	var err error
+
+	// without acknowledgement
+	var resp IBCReceiveResponse
+	err = json.Unmarshal([]byte(`{"acknowledgement":null,"messages":[],"attributes":[],"events":[]}`), &resp)
+	require.NoError(t, err)
+	assert.Equal(t, IBCReceiveResponse{
+		Acknowledgement: nil,
+		Messages:        []SubMsg{},
+		Attributes:      []EventAttribute{},
+		Events:          []Event{},
+	}, resp)
+
+	// with acknowledgement
+	err = json.Unmarshal([]byte(`{"acknowledgement":"YWNr","messages":[],"attributes":[],"events":[]}`), &resp)
+	require.NoError(t, err)
+	assert.Equal(t, IBCReceiveResponse{
+		Acknowledgement: []byte("ack"),
+		Messages:        []SubMsg{},
+		Attributes:      []EventAttribute{},
+		Events:          []Event{},
+	}, resp)
+}
diff --git a/types/msg.go b/types/msg.go
index 6a6323443..016faaea0 100644
--- a/types/msg.go
+++ b/types/msg.go
@@ -31,61 +31,9 @@ type Response struct {
 	Events []Event `json:"events"`
 }
 
-// Events must encode empty array as []
-type Events []Event
-
-// MarshalJSON ensures that we get [] for empty arrays
-func (e Events) MarshalJSON() ([]byte, error) {
-	if len(e) == 0 {
-		return []byte("[]"), nil
-	}
-	var raw []Event = e
-	return json.Marshal(raw)
-}
-
-// UnmarshalJSON ensures that we get [] for empty arrays
-func (e *Events) UnmarshalJSON(data []byte) error {
-	// make sure we deserialize [] back to null
-	if string(data) == "[]" || string(data) == "null" {
-		return nil
-	}
-	var raw []Event
-	if err := json.Unmarshal(data, &raw); err != nil {
-		return err
-	}
-	*e = raw
-	return nil
-}
-
 type Event struct {
-	Type       string          `json:"type"`
-	Attributes EventAttributes `json:"attributes"`
-}
-
-// EventAttributes must encode empty array as []
-type EventAttributes []EventAttribute
-
-// MarshalJSON ensures that we get [] for empty arrays
-func (a EventAttributes) MarshalJSON() ([]byte, error) {
-	if len(a) == 0 {
-		return []byte("[]"), nil
-	}
-	var raw []EventAttribute = a
-	return json.Marshal(raw)
-}
-
-// UnmarshalJSON ensures that we get [] for empty arrays
-func (a *EventAttributes) UnmarshalJSON(data []byte) error {
-	// make sure we deserialize [] back to null
-	if string(data) == "[]" || string(data) == "null" {
-		return nil
-	}
-	var raw []EventAttribute
-	if err := json.Unmarshal(data, &raw); err != nil {
-		return err
-	}
-	*a = raw
-	return nil
+	Type       string                `json:"type"`
+	Attributes Array[EventAttribute] `json:"attributes"`
 }
 
 // EventAttribute
@@ -154,15 +102,15 @@ type BankMsg struct {
 // SendMsg contains instructions for a Cosmos-SDK/SendMsg
 // It has a fixed interface here and should be converted into the proper SDK format before dispatching
 type SendMsg struct {
-	ToAddress string `json:"to_address"`
-	Amount    Coins  `json:"amount"`
+	ToAddress string      `json:"to_address"`
+	Amount    Array[Coin] `json:"amount"`
 }
 
 // BurnMsg will burn the given coins from the contract's account.
 // There is no Cosmos SDK message that performs this, but it can be done by calling the bank keeper.
 // Important if a contract controls significant token supply that must be retired.
 type BurnMsg struct {
-	Amount Coins `json:"amount"`
+	Amount Array[Coin] `json:"amount"`
 }
 
 type IBCMsg struct {
@@ -277,6 +225,7 @@ type TransferMsg struct {
 	ToAddress string     `json:"to_address"`
 	Amount    Coin       `json:"amount"`
 	Timeout   IBCTimeout `json:"timeout"`
+	Memo      string     `json:"memo,omitempty"`
 }
 
 type SendPacketMsg struct {
@@ -335,7 +284,7 @@ type WithdrawDelegatorRewardMsg struct {
 // `depositor` is automatically filled with the current contract's address
 type FundCommunityPoolMsg struct {
 	// Amount is the list of coins to be send to the community pool
-	Amount Coins `json:"amount"`
+	Amount Array[Coin] `json:"amount"`
 }
 
 // AnyMsg is encoded the same way as a protobof [Any](https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/any.proto).
@@ -369,7 +318,7 @@ type ExecuteMsg struct {
 	// as `userMsg` when calling `Handle` on the above-defined contract
 	Msg []byte `json:"msg"`
 	// Send is an optional amount of coins this contract sends to the called contract
-	Funds Coins `json:"funds"`
+	Funds Array[Coin] `json:"funds"`
 }
 
 // InstantiateMsg will create a new contract instance from a previously uploaded CodeID.
@@ -381,7 +330,7 @@ type InstantiateMsg struct {
 	// as `userMsg` when calling `Instantiate` on a new contract with the above-defined CodeID
 	Msg []byte `json:"msg"`
 	// Send is an optional amount of coins this contract sends to the called contract
-	Funds Coins `json:"funds"`
+	Funds Array[Coin] `json:"funds"`
 	// Label is optional metadata to be stored with a contract instance.
 	Label string `json:"label"`
 	// Admin (optional) may be set here to allow future migrations from this address
@@ -397,7 +346,7 @@ type Instantiate2Msg struct {
 	// as `userMsg` when calling `Instantiate` on a new contract with the above-defined CodeID
 	Msg []byte `json:"msg"`
 	// Send is an optional amount of coins this contract sends to the called contract
-	Funds Coins `json:"funds"`
+	Funds Array[Coin] `json:"funds"`
 	// Label is optional metadata to be stored with a contract instance.
 	Label string `json:"label"`
 	// Admin (optional) may be set here to allow future migrations from this address
diff --git a/types/msg_test.go b/types/msg_test.go
index cd8601505..f56915928 100644
--- a/types/msg_test.go
+++ b/types/msg_test.go
@@ -26,7 +26,7 @@ func TestWasmMsgInstantiateSerialization(t *testing.T) {
 	require.Equal(t, "", msg.Instantiate.Admin)
 	require.Equal(t, uint64(7897), msg.Instantiate.CodeID)
 	require.Equal(t, []byte(`{"claim":{}}`), msg.Instantiate.Msg)
-	require.Equal(t, Coins{
+	require.Equal(t, Array[Coin]{
 		{"stones", "321"},
 	}, msg.Instantiate.Funds)
 	require.Equal(t, "my instance", msg.Instantiate.Label)
@@ -47,9 +47,7 @@ func TestWasmMsgInstantiateSerialization(t *testing.T) {
 	require.Equal(t, "king", msg.Instantiate.Admin)
 	require.Equal(t, uint64(7897), msg.Instantiate.CodeID)
 	require.Equal(t, []byte(`{"claim":{}}`), msg.Instantiate.Msg)
-	require.Equal(t, Coins{
-		{"stones", "321"},
-	}, msg.Instantiate.Funds)
+	require.Equal(t, Array[Coin]{}, msg.Instantiate.Funds)
 	require.Equal(t, "my instance", msg.Instantiate.Label)
 }
 
@@ -70,7 +68,7 @@ func TestWasmMsgInstantiate2Serialization(t *testing.T) {
 	require.Equal(t, "", msg.Instantiate2.Admin)
 	require.Equal(t, uint64(7897), msg.Instantiate2.CodeID)
 	require.Equal(t, []byte(`{"claim":{}}`), msg.Instantiate2.Msg)
-	require.Equal(t, Coins{
+	require.Equal(t, Array[Coin]{
 		{"stones", "321"},
 	}, msg.Instantiate2.Funds)
 	require.Equal(t, "my instance", msg.Instantiate2.Label)
@@ -161,5 +159,5 @@ func TestMsgFundCommunityPoolSerialization(t *testing.T) {
 	err := json.Unmarshal(document, &msg)
 	require.NoError(t, err)
 
-	require.Equal(t, Coins{{"adenom", "300"}, {"bdenom", "400"}}, msg.FundCommunityPool.Amount)
+	require.Equal(t, Array[Coin]{{"adenom", "300"}, {"bdenom", "400"}}, msg.FundCommunityPool.Amount)
 }
diff --git a/types/queries.go b/types/queries.go
index 32ee88dbe..748003bee 100644
--- a/types/queries.go
+++ b/types/queries.go
@@ -143,7 +143,7 @@ type AllBalancesQuery struct {
 
 // AllBalancesResponse is the expected response to AllBalancesQuery
 type AllBalancesResponse struct {
-	Amount Coins `json:"amount"`
+	Amount Array[Coin] `json:"amount"`
 }
 
 type DenomMetadataQuery struct {
@@ -192,59 +192,7 @@ type ListChannelsQuery struct {
 }
 
 type ListChannelsResponse struct {
-	Channels IBCChannels `json:"channels"`
-}
-
-// IBCChannels must JSON encode empty array as [] (not null) for consistency with Rust parser
-type IBCChannels []IBCChannel
-
-// MarshalJSON ensures that we get [] for empty arrays
-func (e IBCChannels) MarshalJSON() ([]byte, error) {
-	if len(e) == 0 {
-		return []byte("[]"), nil
-	}
-	var raw []IBCChannel = e
-	return json.Marshal(raw)
-}
-
-// UnmarshalJSON ensures that we get [] for empty arrays
-func (e *IBCChannels) UnmarshalJSON(data []byte) error {
-	// make sure we deserialize [] back to null
-	if string(data) == "[]" || string(data) == "null" {
-		return nil
-	}
-	var raw []IBCChannel
-	if err := json.Unmarshal(data, &raw); err != nil {
-		return err
-	}
-	*e = raw
-	return nil
-}
-
-// IBCEndpoints must JSON encode empty array as [] (not null) for consistency with Rust parser
-type IBCEndpoints []IBCEndpoint
-
-// MarshalJSON ensures that we get [] for empty arrays
-func (e IBCEndpoints) MarshalJSON() ([]byte, error) {
-	if len(e) == 0 {
-		return []byte("[]"), nil
-	}
-	var raw []IBCEndpoint = e
-	return json.Marshal(raw)
-}
-
-// UnmarshalJSON ensures that we get [] for empty arrays
-func (e *IBCEndpoints) UnmarshalJSON(data []byte) error {
-	// make sure we deserialize [] back to null
-	if string(data) == "[]" || string(data) == "null" {
-		return nil
-	}
-	var raw []IBCEndpoint
-	if err := json.Unmarshal(data, &raw); err != nil {
-		return err
-	}
-	*e = raw
-	return nil
+	Channels Array[IBCChannel] `json:"channels"`
 }
 
 type ChannelQuery struct {
@@ -270,33 +218,7 @@ type AllValidatorsQuery struct{}
 
 // AllValidatorsResponse is the expected response to AllValidatorsQuery
 type AllValidatorsResponse struct {
-	Validators Validators `json:"validators"`
-}
-
-// Validators must JSON encode empty array as []
-type Validators []Validator
-
-// MarshalJSON ensures that we get [] for empty arrays
-func (v Validators) MarshalJSON() ([]byte, error) {
-	if len(v) == 0 {
-		return []byte("[]"), nil
-	}
-	var raw []Validator = v
-	return json.Marshal(raw)
-}
-
-// UnmarshalJSON ensures that we get [] for empty arrays
-func (v *Validators) UnmarshalJSON(data []byte) error {
-	// make sure we deserialize [] back to null
-	if string(data) == "[]" || string(data) == "null" {
-		return nil
-	}
-	var raw []Validator
-	if err := json.Unmarshal(data, &raw); err != nil {
-		return err
-	}
-	*v = raw
-	return nil
+	Validators Array[Validator] `json:"validators"`
 }
 
 type ValidatorQuery struct {
@@ -330,32 +252,7 @@ type DelegationQuery struct {
 
 // AllDelegationsResponse is the expected response to AllDelegationsQuery
 type AllDelegationsResponse struct {
-	Delegations Delegations `json:"delegations"`
-}
-
-type Delegations []Delegation
-
-// MarshalJSON ensures that we get [] for empty arrays
-func (d Delegations) MarshalJSON() ([]byte, error) {
-	if len(d) == 0 {
-		return []byte("[]"), nil
-	}
-	var raw []Delegation = d
-	return json.Marshal(raw)
-}
-
-// UnmarshalJSON ensures that we get [] for empty arrays
-func (d *Delegations) UnmarshalJSON(data []byte) error {
-	// make sure we deserialize [] back to null
-	if string(data) == "[]" || string(data) == "null" {
-		return nil
-	}
-	var raw []Delegation
-	if err := json.Unmarshal(data, &raw); err != nil {
-		return err
-	}
-	*d = raw
-	return nil
+	Delegations Array[Delegation] `json:"delegations"`
 }
 
 type Delegation struct {
@@ -417,17 +314,17 @@ type DelegatorValidatorsResponse struct {
 	Validators []string `json:"validators"`
 }
 
-// DelegationResponse is the expected response to DelegationsQuery
+// DelegationResponse is the expected response to Array[Delegation]Query
 type DelegationResponse struct {
 	Delegation *FullDelegation `json:"delegation,omitempty"`
 }
 
 type FullDelegation struct {
-	Delegator          string `json:"delegator"`
-	Validator          string `json:"validator"`
-	Amount             Coin   `json:"amount"`
-	AccumulatedRewards Coins  `json:"accumulated_rewards"`
-	CanRedelegate      Coin   `json:"can_redelegate"`
+	Delegator          string      `json:"delegator"`
+	Validator          string      `json:"validator"`
+	Amount             Coin        `json:"amount"`
+	AccumulatedRewards Array[Coin] `json:"accumulated_rewards"`
+	CanRedelegate      Coin        `json:"can_redelegate"`
 }
 
 type BondedDenomResponse struct {
diff --git a/types/queries_test.go b/types/queries_test.go
index 2ec87f68e..8dd52dc8d 100644
--- a/types/queries_test.go
+++ b/types/queries_test.go
@@ -9,19 +9,19 @@ import (
 )
 
 func TestDelegationWithEmptyArray(t *testing.T) {
-	var del Delegations
+	var del Array[Delegation]
 	bz, err := json.Marshal(&del)
 	require.NoError(t, err)
 	assert.Equal(t, string(bz), `[]`)
 
-	var redel Delegations
+	var redel Array[Delegation]
 	err = json.Unmarshal(bz, &redel)
 	require.NoError(t, err)
-	assert.Nil(t, redel)
+	assert.Equal(t, Array[Delegation]{}, redel)
 }
 
 func TestDelegationWithData(t *testing.T) {
-	del := Delegations{{
+	del := Array[Delegation]{{
 		Validator: "foo",
 		Delegator: "bar",
 		Amount:    NewCoin(123, "stake"),
@@ -29,26 +29,26 @@ func TestDelegationWithData(t *testing.T) {
 	bz, err := json.Marshal(&del)
 	require.NoError(t, err)
 
-	var redel Delegations
+	var redel Array[Delegation]
 	err = json.Unmarshal(bz, &redel)
 	require.NoError(t, err)
 	assert.Equal(t, redel, del)
 }
 
 func TestValidatorWithEmptyArray(t *testing.T) {
-	var val Validators
+	var val Array[Validator]
 	bz, err := json.Marshal(&val)
 	require.NoError(t, err)
 	assert.Equal(t, string(bz), `[]`)
 
-	var reval Validators
+	var reval Array[Validator]
 	err = json.Unmarshal(bz, &reval)
 	require.NoError(t, err)
-	assert.Nil(t, reval)
+	assert.Equal(t, Array[Validator]{}, reval)
 }
 
 func TestValidatorWithData(t *testing.T) {
-	val := Validators{{
+	val := Array[Validator]{{
 		Address:       "1234567890",
 		Commission:    "0.05",
 		MaxCommission: "0.1",
@@ -57,7 +57,7 @@ func TestValidatorWithData(t *testing.T) {
 	bz, err := json.Marshal(&val)
 	require.NoError(t, err)
 
-	var reval Validators
+	var reval Array[Validator]
 	err = json.Unmarshal(bz, &reval)
 	require.NoError(t, err)
 	assert.Equal(t, reval, val)
diff --git a/types/submessages.go b/types/submessages.go
index 93eda1808..faaa14a53 100644
--- a/types/submessages.go
+++ b/types/submessages.go
@@ -81,6 +81,12 @@ type SubMsgResult struct {
 // with full Cosmos SDK events.
 // This mirrors Rust's SubMsgResponse.
 type SubMsgResponse struct {
-	Events Events `json:"events"`
-	Data   []byte `json:"data,omitempty"`
+	Events       Array[Event]       `json:"events"`
+	Data         []byte             `json:"data,omitempty"`
+	MsgResponses Array[MsgResponse] `json:"msg_responses"`
+}
+
+type MsgResponse struct {
+	TypeURL string `json:"type_url"`
+	Value   []byte `json:"value"`
 }
diff --git a/types/submessages_test.go b/types/submessages_test.go
index 336ce1cdc..0c9ab5401 100644
--- a/types/submessages_test.go
+++ b/types/submessages_test.go
@@ -13,10 +13,10 @@ func TestReplySerialization(t *testing.T) {
 		ID:      75,
 		Result: SubMsgResult{
 			Ok: &SubMsgResponse{
-				Events: []Event{
+				Events: Array[Event]{
 					{
 						Type: "hi",
-						Attributes: []EventAttribute{
+						Attributes: Array[EventAttribute]{
 							{
 								Key:   "si",
 								Value: "claro",
@@ -25,10 +25,30 @@ func TestReplySerialization(t *testing.T) {
 					},
 				},
 				Data: []byte{0x3f, 0x00, 0xaa, 0x5c, 0xab},
+				MsgResponses: Array[MsgResponse]{
+					MsgResponse{
+						TypeURL: "/cosmos.bank.v1beta1.MsgSendResponse",
+						Value:   []byte{},
+					},
+				},
 			},
 		},
 	}
 	serialized, err := json.Marshal(&reply1)
 	require.NoError(t, err)
-	require.Equal(t, `{"gas_used":4312324,"id":75,"result":{"ok":{"events":[{"type":"hi","attributes":[{"key":"si","value":"claro"}]}],"data":"PwCqXKs="}}}`, string(serialized))
+	require.Equal(t, `{"gas_used":4312324,"id":75,"result":{"ok":{"events":[{"type":"hi","attributes":[{"key":"si","value":"claro"}]}],"data":"PwCqXKs=","msg_responses":[{"type_url":"/cosmos.bank.v1beta1.MsgSendResponse","value":""}]}}}`, string(serialized))
+}
+
+func TestSubMsgResponseSerialization(t *testing.T) {
+	response := SubMsgResponse{}
+	document, err := json.Marshal(response)
+	require.NoError(t, err)
+	require.Equal(t, `{"events":[],"msg_responses":[]}`, string(document))
+
+	// we really only care about marshal, but let's test unmarshal too
+	document2 := []byte(`{}`)
+	var response2 SubMsgResponse
+	err = json.Unmarshal(document2, &response2)
+	require.NoError(t, err)
+	require.Equal(t, response, response2)
 }
diff --git a/types/types.go b/types/types.go
index b98765b21..a8cca6dd6 100644
--- a/types/types.go
+++ b/types/types.go
@@ -55,7 +55,7 @@ type CanonicalAddress = []byte
 // Coin is a string representation of the sdk.Coin type (more portable than sdk.Int)
 type Coin struct {
 	Denom  string `json:"denom"`  // type, eg. "ATOM"
-	Amount string `json:"amount"` // string encoing of decimal value, eg. "12.3456"
+	Amount string `json:"amount"` // string encoding of decimal value, eg. "12.3456"
 }
 
 func NewCoin(amount uint64, denom string) Coin {
@@ -65,32 +65,6 @@ func NewCoin(amount uint64, denom string) Coin {
 	}
 }
 
-// Coins handles properly serializing empty amounts
-type Coins []Coin
-
-// MarshalJSON ensures that we get [] for empty arrays
-func (c Coins) MarshalJSON() ([]byte, error) {
-	if len(c) == 0 {
-		return []byte("[]"), nil
-	}
-	var d []Coin = c
-	return json.Marshal(d)
-}
-
-// UnmarshalJSON ensures that we get [] for empty arrays
-func (c *Coins) UnmarshalJSON(data []byte) error {
-	// make sure we deserialize [] back to null
-	if string(data) == "[]" || string(data) == "null" {
-		return nil
-	}
-	var d []Coin
-	if err := json.Unmarshal(data, &d); err != nil {
-		return err
-	}
-	*c = d
-	return nil
-}
-
 // Replicating the cosmos-sdk bank module Metadata type
 type DenomMetadata struct {
 	Description string `json:"description"`
@@ -209,3 +183,35 @@ type Metrics struct {
 	// Cumulative size of all elements in memory cache (in bytes)
 	SizeMemoryCache uint64
 }
+
+// Array is a wrapper around a slice that ensures that we get "[]" JSON for nil values.
+// When unmarshaling, we get an empty slice for "[]" and "null".
+//
+// This is needed for fields that are "Vec<C>" on the Rust side because `null` values
+// will result in an error there.
+// Using this on a field with an "Option<Vec<C>>" type on the Rust side would
+// never result in a "None" value on the Rust side, making the "Option" pointless.
+type Array[C any] []C
+
+// MarshalJSON ensures that we get "[]" for nil arrays
+func (a Array[C]) MarshalJSON() ([]byte, error) {
+	if len(a) == 0 {
+		return []byte("[]"), nil
+	}
+	var raw []C = a
+	return json.Marshal(raw)
+}
+
+// UnmarshalJSON ensures that we get an empty slice for "[]" and "null"
+func (a *Array[C]) UnmarshalJSON(data []byte) error {
+	var raw []C
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return err
+	}
+	// make sure we deserialize [] back to empty slice
+	if len(raw) == 0 {
+		raw = []C{}
+	}
+	*a = raw
+	return nil
+}
diff --git a/types/types_test.go b/types/types_test.go
index af1d472e5..172a3ca9c 100644
--- a/types/types_test.go
+++ b/types/types_test.go
@@ -84,3 +84,53 @@ func TestInt64JSON(t *testing.T) {
 	err = json.Unmarshal([]byte(`""`), &i)
 	require.EqualError(t, err, "cannot unmarshal \"\" into Int64, failed to parse integer")
 }
+
+func TestArraySerialization(t *testing.T) {
+	var arr Array[string]
+
+	// unmarshal empty
+	err := json.Unmarshal([]byte(`[]`), &arr)
+	require.NoError(t, err)
+	require.Equal(t, Array[string]{}, arr)
+	err = json.Unmarshal([]byte(`[ ]`), &arr)
+	require.NoError(t, err)
+	require.Equal(t, Array[string]{}, arr)
+	err = json.Unmarshal([]byte(` []`), &arr)
+	require.NoError(t, err)
+	require.Equal(t, Array[string]{}, arr)
+
+	// unmarshal null
+	err = json.Unmarshal([]byte(`null`), &arr)
+	require.NoError(t, err)
+	require.Equal(t, Array[string]{}, arr)
+
+	// unmarshal filled
+	err = json.Unmarshal([]byte(`["a","b"]`), &arr)
+	require.NoError(t, err)
+	require.Equal(t, Array[string]{"a", "b"}, arr)
+
+	// marshal filled
+	bz, err := json.Marshal(arr)
+	require.NoError(t, err)
+	require.Equal(t, `["a","b"]`, string(bz))
+
+	// marshal null
+	bz, err = json.Marshal(Array[string](nil))
+	require.NoError(t, err)
+	require.Equal(t, `[]`, string(bz))
+
+	// marshal empty
+	bz, err = json.Marshal(Array[uint64]{})
+	require.NoError(t, err)
+	require.Equal(t, `[]`, string(bz))
+
+	// unmarshal elements
+	var arr2 Array[uint64]
+	err = json.Unmarshal([]byte(`[1,2]`), &arr2)
+	require.NoError(t, err)
+	require.Equal(t, Array[uint64]{1, 2}, arr2)
+	// unmarshal null into the same pointer
+	err = json.Unmarshal([]byte(`null`), &arr2)
+	require.NoError(t, err)
+	require.Equal(t, Array[uint64]{}, arr2)
+}