Intro

What are CoW Hooks?

CoW Hooks is a feature of CoW Protocol that allows you to do any arbitrary on-chain execution before (pre-hooks) and after (post-hooks) a trade happens.

CoW Hooks allows to integrate with any DeFI protocol, in other words, it extends the intent framework to enable not only to swap but also to execute, prepare, or post process the swap.

In what networks can I use hooks?

All networks where CoW Protocol is available, at the time of writing this, are:

Mainnet, Gnosis Chain, Arbitrum, and Sepolia.

Check the full list here: https://docs.cow.fi/cow-protocol/reference/sdks/cow-sdk/enums/SupportedChainId

Who executes the hooks?

The solvers. When they post the settlement solution for a batch of trades, they will also execute all the pre/post hooks.

This will allow users to do all these deFI interactions in a gas-less fashion.

Integration

What does a hook look like?

A hook is defined by 3 fields that model an Ethereum call:

• target: Target contract. The address that would be called
• callData: The data of the Ethereum call
• gasLimit: Gas needed to execute the call. This gas would be paid to the solver in sellToken, and its part of the fees paid to solvers. UI like CoW Swap will take this into account to show the execution fee to the user.

More details in: https://docs.cow.fi/cow-protocol/reference/core/intents/hooks

Can I see an example?

Let’s take this Gnosis Chain as an example: