Hooks
Hooks are powerful add-ons to keys which can perform arbitrary validation on signatures, and/or actions during execution time.
There are two subtypes of hooks: ValidationHook
and ExecutionHook
. A hook can implement either, or both interfaces.
Validation hooks have three call sites:
afterVerifySignature
afterIsValidSignature
afterValidateUserOp
Execution hooks have two call sites:
beforeExecute
afterExecute
Hooks must revert to indicate that the given action should revert.
Example functionality which can be implemented in hooks includes:
- Spending limits
- Restricting keys from calling certain contracts and methods
- Turning a key into a multisig, effectively requiring additional signatures for verification
- Automated actions pre/post swaps
There are a few example hooks referenced in the repo. Be aware that these example hooks are not production code and may contain bugs. We do not recommend you to deploy these hooks or use them as reference implementations for productionized code. They are proof of concepts.