diff --git a/code/xcvm/cosmwasm/contracts/gateway/src/contract/ibc/xcvm.rs b/code/xcvm/cosmwasm/contracts/gateway/src/contract/ibc/xcvm.rs
index f76c9129ab0..bf8799643cb 100644
--- a/code/xcvm/cosmwasm/contracts/gateway/src/contract/ibc/xcvm.rs
+++ b/code/xcvm/cosmwasm/contracts/gateway/src/contract/ibc/xcvm.rs
@@ -91,7 +91,7 @@ pub fn ibc_packet_receive(
 ) -> Result<IbcReceiveResponse> {
 	let response = IbcReceiveResponse::default().add_event(make_event("receive"));
 	let msg = (|| -> Result<_> {
-		let packet = XcPacket::try_decode(&msg.packet.data)?;
+		let packet = XcPacket::decode(&msg.packet.data)?;
 		let call_origin = CallOrigin::Remote { user_origin: packet.user_origin };
 		let execute_program = msg::ExecuteProgramMsg {
 			salt: packet.salt,
@@ -119,7 +119,7 @@ pub fn ibc_packet_receive(
 pub fn ibc_packet_ack(_deps: DepsMut, _env: Env, msg: IbcPacketAckMsg) -> Result<IbcBasicResponse> {
 	let ack = XCVMAck::try_from(msg.acknowledgement.data.as_slice())
 		.map_err(|_| ContractError::InvalidAck)?;
-	XcPacket::try_decode(&msg.original_packet.data)?;
+	XcPacket::decode(&msg.original_packet.data)?;
 	Ok(IbcBasicResponse::default().add_event(make_event("ack").add_attribute("ack", ack)))
 }
 
@@ -129,7 +129,7 @@ pub fn ibc_packet_timeout(
 	_env: Env,
 	msg: IbcPacketTimeoutMsg,
 ) -> Result<IbcBasicResponse> {
-	XcPacket::try_decode(&msg.packet.data)?;
+	XcPacket::decode(&msg.packet.data)?;
 	// https://github.com/cosmos/ibc/pull/998
 	Ok(IbcBasicResponse::default())
 }
diff --git a/code/xcvm/lib/core/src/proto.rs b/code/xcvm/lib/core/src/proto.rs
index 1ea090e0b74..d37e113936e 100644
--- a/code/xcvm/lib/core/src/proto.rs
+++ b/code/xcvm/lib/core/src/proto.rs
@@ -2,6 +2,7 @@ use prost::Message as _;
 
 pub mod common;
 pub mod pb;
+pub mod result;
 pub mod xcvm;
 
 /// Defines an isomorphism between a Rust type `Self` and a protocol message.
@@ -10,35 +11,29 @@ pub mod xcvm;
 /// type from binary representation of the protobuf.
 pub trait Isomorphism: Sized {
 	/// Protobuf self is isomorphic with.
-	type Message: prost::Message;
+	type Message: Default + From<Self> + TryInto<Self> + prost::Message;
 
 	/// Converts object to protobuf and encodes it as byte vector.
-	fn encode(self) -> alloc::vec::Vec<u8>
-	where
-		Self::Message: From<Self>,
-	{
+	fn encode(self) -> alloc::vec::Vec<u8> {
 		Self::Message::encode_to_vec(&self.into())
 	}
 
-	/// Decodes a protobuf and then converts it to `T`.
-	fn decode(buffer: &[u8]) -> Result<Self, prost::DecodeError>
-	where
-		Self::Message: Default + Into<Self>,
-	{
-		Self::Message::decode(buffer).map(|msg| msg.into())
-	}
-
 	/// Decodes a protobuf and then tries to convert it to `T`.
-	fn try_decode(buffer: &[u8]) -> Result<Self, DecodeError>
-	where
-		Self::Message: Default + TryInto<Self>,
-	{
+	fn decode(buffer: &[u8]) -> Result<Self, DecodeError> {
 		Self::Message::decode(buffer)?
 			.try_into()
 			.map_err(|_| DecodeError::BadIsomorphism)
 	}
 }
 
+impl Isomorphism for alloc::string::String {
+	type Message = Self;
+}
+
+impl Isomorphism for () {
+	type Message = ();
+}
+
 /// Error when trying to decode protobuf into a Rust type.
 #[derive(Clone, Debug, derive_more::From)]
 pub enum DecodeError {
diff --git a/code/xcvm/lib/core/src/proto/result.rs b/code/xcvm/lib/core/src/proto/result.rs
new file mode 100644
index 00000000000..af3287a7dbe
--- /dev/null
+++ b/code/xcvm/lib/core/src/proto/result.rs
@@ -0,0 +1,63 @@
+use super::{Isomorphism, NonEmptyExt};
+use prost::Message;
+
+/// A generic definition of a protocol message with an Ok and Err variants.
+#[derive(Clone, PartialEq, Message)]
+pub struct ResultMessage<T: Default + Send + Sync + Message, E: Default + Send + Sync + Message> {
+	#[prost(oneof = "ResultEnum", tags = "1, 2")]
+	pub result: core::option::Option<ResultEnum<T, E>>,
+}
+
+/// Nested enum type in [`ResultMessage`].
+#[derive(Clone, PartialEq, prost::Oneof)]
+pub enum ResultEnum<T: Default + Send + Sync + Message, E: Default + Send + Sync + Message> {
+	#[prost(message, tag = "1")]
+	Ok(T),
+	#[prost(message, tag = "2")]
+	Err(E),
+}
+
+impl<T, E> Isomorphism for Result<T, E>
+where
+	T: Isomorphism,
+	T::Message: Default + Send + Sync + TryInto<T> + From<T>,
+	E: Isomorphism,
+	E::Message: Default + Send + Sync + TryInto<E> + From<E>,
+{
+	type Message = ResultMessage<T::Message, E::Message>;
+}
+
+impl<T: Isomorphism, E: Isomorphism> TryFrom<ResultMessage<T::Message, E::Message>>
+	for Result<T, E>
+{
+	type Error = ();
+	fn try_from(result: ResultMessage<T::Message, E::Message>) -> Result<Self, Self::Error> {
+		match result.result.non_empty()? {
+			ResultEnum::Ok(ok) => Ok(Ok(ok.try_into().map_err(|_| ())?)),
+			ResultEnum::Err(ok) => Ok(Err(ok.try_into().map_err(|_| ())?)),
+		}
+	}
+}
+
+impl<T: Isomorphism, E: Isomorphism> From<Result<T, E>> for ResultMessage<T::Message, E::Message> {
+	fn from(result: Result<T, E>) -> Self {
+		let result = match result {
+			Ok(ok) => ResultEnum::Ok(ok.into()),
+			Err(err) => ResultEnum::Err(err.into()),
+		};
+		Self { result: Some(result) }
+	}
+}
+
+#[test]
+fn test_encoding() {
+	let want = Result::<String, String>::Ok("ok".into());
+	let encoded = want.clone().encode();
+	let got = Result::<String, String>::decode(encoded.as_slice()).unwrap();
+	assert_eq!(want, got);
+
+	let want = Result::<String, String>::Err("err".into());
+	let encoded = want.clone().encode();
+	let got = Result::<String, String>::decode(encoded.as_slice()).unwrap();
+	assert_eq!(want, got);
+}
diff --git a/code/xcvm/lib/core/src/proto/xcvm.rs b/code/xcvm/lib/core/src/proto/xcvm.rs
index 7184615806d..90f6e1e7141 100644
--- a/code/xcvm/lib/core/src/proto/xcvm.rs
+++ b/code/xcvm/lib/core/src/proto/xcvm.rs
@@ -23,9 +23,10 @@ pub type XCVMProgram<TAbiEncoded, TAccount, TAssets> =
 impl<TAbiEncoded, TAccount, TAssets> super::Isomorphism
 	for XCVMPacket<TAbiEncoded, TAccount, TAssets>
 where
-	TAbiEncoded: Into<Vec<u8>>,
-	TAccount: Into<Vec<u8>>,
-	TAssets: Into<Vec<(crate::AssetId, crate::Balance)>>,
+	TAbiEncoded: TryFrom<Vec<u8>> + Into<Vec<u8>>,
+	TAccount: TryFrom<Vec<u8>> + Into<Vec<u8>>,
+	TAssets:
+		From<Vec<(crate::AssetId, crate::Balance)>> + Into<Vec<(crate::AssetId, crate::Balance)>>,
 {
 	type Message = pb::xcvm::Packet;
 }
@@ -33,9 +34,10 @@ where
 impl<TAbiEncoded, TAccount, TAssets> super::Isomorphism
 	for XCVMProgram<TAbiEncoded, TAccount, TAssets>
 where
-	TAbiEncoded: Into<Vec<u8>>,
-	TAccount: Into<Vec<u8>>,
-	TAssets: Into<Vec<(crate::AssetId, crate::Balance)>>,
+	TAbiEncoded: TryFrom<Vec<u8>> + Into<Vec<u8>>,
+	TAccount: TryFrom<Vec<u8>> + Into<Vec<u8>>,
+	TAssets:
+		From<Vec<(crate::AssetId, crate::Balance)>> + Into<Vec<(crate::AssetId, crate::Balance)>>,
 {
 	type Message = pb::xcvm::Program;
 }