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Outposts

Outposts leverage the IBC Transfer Extension to interact with other chains through the creation of a custom memo field that holds instructions for the reception chain. This allows users to interact with other chains without leaving the Evmos chain. Evmos supports two outposts at the moment:

  1. Osmosis Cross Chain Swaps Outpost
  2. Stride Liquid Staking and Redeeming Outpost

Key Components​

Common​

  • memo field: An extra JSON string attached to IBC Transfer packets. This additional information helps the receiving chain to identify the user and action to be performed.
  • ICS20 Transfers: Protocol for transferring fungible tokens using Inter-Blockchain Communication (IBC).
  • ICS20 Extension: A precompiled contract that allows users to send IBC transfers to other chains through the EVM.

Stride Specific​

  • Stride Autopilot Middleware: A module simplifying user steps for using Stride services like liquid staking and redeeming.

Osmosis Specific​

  • Osmosis IBC Hooks Middleware: Middleware on Osmosis that interprets the memo field for specific actions.
  • Osmosis SwapRouter: A contract that manages routes to pools on Osmosis, defining how tokens are swapped.
  • Osmosis Cross-Chain Swap V1 (XCS): Handles processing of the memo field. This executes token swaps or routes tokens to their destination chains. Evmos has its own XCS contract deployed on the Osmosis chain. You can find it here.

Stride Outpost​

The Stride Outpost interacts with the Autopilot middleware of the Stride protocol. It simplifies using Stride Autopilot for liquid staking and claiming EVMOS tokens with a single transaction and returns stEVMOS back to the Evmos chain. This Outpost automatically builds the correct packet data so users can easily interact with the Stride protocol without leaving the Evmos chain.

Users can interact with the Stride Outpost directly using the Stride instant dApp from the Evmos dApp store. The dApp will automatically build the correct memo field for the user and send the IBC transfer to the Stride chain. The possible actions are:

  1. Liquid Stake - Stake EVMOS tokens and receive stEVMOS tokens in return.
  2. Redeem - Unstake stEVMOS tokens and receive EVMOS tokens back within 14-16 days. Check the Stride documentation for more info on redeeming.

Osmosis Outpost​

The Osmosis Outpost interacts with the Osmosis IBC-hooks middleware, the Osmosis SwapRouter contract and the Cross Chain Swaps contract. It provides an easy-to-use interface for executing token swaps between Osmosis and Evmos and vice versa and routes them back to the Evmos chain.

Users can interact with the Osmosis Outpost directly using the Osmosis Instant dApp from the Evmos dApp store. The dApp will automatically build the correct memo field for the user and send the IBC transfer to the Osmosis chain. The possible actions are:

  1. Swap Osmosis for Evmos - Send your Osmosis tokens to the Osmosis Outpost and receive Evmos tokens in return.
  2. Swap Evmos for Osmosis - Send your Evmos tokens to the Osmosis Outpost and receive Osmosis tokens in return.

Fallback Mechanism​

Each Outpost has a fallback mechanism in the extraordinary case of core protocol or middleware failures. In case you do not receive your stEvmos back or your swap isn't executed make sure to contact the mod team on Discord or Telegram and we will help you recover your funds.

Stride​

The Stride Outpost has a fallback mechanism in case the Autopilot middleware is not available or is not working correctly. This is why each IBC Transfer is sent to a specific address on the Stride chain. This address is a multi-sig account controlled by the AP team that will return any stuck funds to the original sender.

Stride Multi-sig: stride1yzw585gd8ajymcaqt9e98k5tt66qpzspc93ghf

  • Vlad (Evmos Core Team): stride1rhe5leyt5w0mcwd9rpp93zqn99yktsxvyaqgd0
  • Mr.Sir (Evmos Core Team): stride1r4xzzuqewfwm4uckugcnt246xpjsv3a92epau2
  • Daniel (Evmos Core Team): stride1wwc0fdes0y33czhg48yafmle0xpkfg860wkh9g

Osmosis​

The Osmosis Outpost has a fallback mechanism in case the IBC Hooks middleware is not working correctly. This is why the memo field contains a special field called local_recovery_addr that will be used as a fallback predetermined address in case of failures. This address is a multi-sig account controlled by the AP team that will return any stuck funds to the original sender.

Osmosis Multi-sig: osmo1yzw585gd8ajymcaqt9e98k5tt66qpzspn4zy4h

  • Vlad (Evmos Core Team): osmo1rhe5leyt5w0mcwd9rpp93zqn99yktsxv0dny03
  • Mr.Sir (Evmos Core Team): osmo1r4xzzuqewfwm4uckugcnt246xpjsv3a9pfj375
  • Daniel (Evmos Core Team): osmo1wwc0fdes0y33czhg48yafmle0xpkfg86y79m8k

For Developers​

If you are a developer and want to integrate the Stride or Osmosis Outpost into your dApp, you can find an example Solidity implementation on our extension repo:

  1. Osmosis Outpost
  2. Stride Outpost