This section includes a summary of the supported and planned features. A feature matrix and comparison between the Rust and Go relayer implementations can be found in the Feature Matrix

Cosmos SDK compatibility: Hermes supports Cosmos SDK chains implementing the IBC v1.1 protocol specification. Cosmos SDK versions 0.41.3 to 0.44.x are officially supported. In case Hermes finds an incompatible SDK version, it will output a log warning.

Supported Features

  • Basic features
    • create and update clients
    • refresh clients to prevent expiration
    • establish connections with new or existing clients
    • establish channels with new or existing connection
    • channel closing handshake
    • relay packets, acknowledgments, timeout and timeout-on-close packets, with zero or non-zero delay.
    • queries for all objects
  • Packet relaying over:
    • multiple paths, for the chains in config.toml
  • Restart support
    • clear packets
    • resume channel handshake if configured to relay all
    • resume connection handshake if configured to relay all
  • Client upgrade
    • upgrading clients after a counterparty chain has performed an upgrade for IBC breaking changes
  • Packet delay:
    • establish path over non-zero delay connection
    • relay all packets with the specified delay
  • Monitor and submit misbehaviour for clients
    • monitor client updates for misbehaviour (fork and BFT time violation)
    • submit misbehaviour evidence to the on-chain IBC client.

    misbehaviour submission to full node not yet supported

  • Individual commands that build and send transactions for:
    • creating and updating IBC Tendermint light clients
    • sending connection open handshake datagrams
    • sending channel open handshake datagrams
    • sending channel closing handshake datagrams
    • initiating a cross chain transfer (mainly for testing)
    • relaying sent packets, acknowledgments and timeouts
    • client upgrade
  • Channel handshake for existing channel that is not in Open state
  • Connection handshake for existing connection that is not in Open state
  • Telemetry support

Upcoming / Unsupported Features

Planned features:

  • Full Passive mode: relay from all IBC events
    • Connection handshake for existing connection that is not in Open state
  • Relayer support for management application (add RPC server)
  • Dynamic configuration management

Not planned:

  • Relayer management application
  • Create clients with user chosen parameters (such as UpgradePath)
  • Use IBC light clients other than Tendermint such as Solo Machine
  • Support non cosmos-SDK chains