#ibc #consensus #tendermint #cosmos #blockchain #data-structures

no-std ibc-types-core-client

Data types for the Inter-Blockchain Communication (IBC) protocol. This crate defines common data structures that can be reused by different IBC implementations or ecosystem tooling

15 releases (9 breaking)

new 0.13.0 Apr 4, 2024
0.12.0 Mar 1, 2024
0.11.1 Jan 31, 2024
0.11.0 Dec 30, 2023
0.10.0 Nov 27, 2023

#42 in #tendermint

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Used in 5 crates


1.5K SLoC


This crate defines common data structures for Inter-Blockchain Communication (IBC) messages that can be reused by different IBC implementations or IBC ecosystem tooling.

Unlike ibc-rs, which provides a specific and opinionated implementation of IBC, ibc-types just defines Rust types that allow working with IBC messages, allowing an IBC implementation or IBC ecosystem tooling to be built on top using a common language.

In addition to defining Rust types for IBC messages, ibc-types also defines Rust types for IBC events, and provides code for parsing IBC events to and from ABCI messages. IBC events are de facto a critical part of IBC, in that they're needed to interoperate with relayers, but are not really specified anywhere. Providing event parsing code in ibc-types allows IBC implementations and relayer implementations to share common code for producing and consuming events.

The ibc-types crate is a top-level wrapper crate re-exporting the contents of subcrates scoped by IBC module. This structure means that external users of the library can use one catch-all crate, but allows dependency relationships between different IBC modules. For example, the ibc-types crate re-exports the client types defined in the ibc-types-core-client crate, as well as the types for the Tendermint light client defined in the ibc-types-lightclients-tendermint crate. But because these are separate crates, the Tendermint light client types can depend on the core IBC client types, preventing cyclic dependency issues.


IBC is specified in English in the cosmos/ibc repo. Any protocol changes or clarifications should be contributed there.

This repo contains Rust datatypes modeling IBC messages.


We follow Semantic Versioning, though APIs are still under active development.



Copyright © 2023 ibc-types authors.

This crate was originally forked from ibc-rs:

Copyright © 2022 Informal Systems Inc. and ibc-rs authors.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use the files in this repository except in compliance with the License. You may obtain a copy of the License at


Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.


~330K SLoC