Check Mate
Check Mate allows to compose and setup a suite of multiple on-chain transaction checks in your smart contract account.
About
The problem it solves The *Safe* (formerly *Gnosis Safe*) allows to setup a transaction guard that performs some checks before and after the state changes when executing a transaction. *Check Mate* allows to set up a transaction guard that manages multiple guards, composing and ordering by priority all the on-chain transaction checks that are performed. This adds some benefits to the initial solution: - Only devs who can write smart contracts can use a one-guard solution that is customized to fit their needs. - Having all the transaction checks in just one guard implies that it has to be updated every time the checked conditions change increasing the risk of introducing new bugs. - A modular solution allows to easily add and remove specific checks and build a customized check suite for your smart contract account in a no-code way for the user. - Creating small and specific checks as public goods that can be easily reused and composed by the community will increase the adoption of transaction guards, allowing a lot more people to benefit from them.
How it's made
Challenges we ran into - Transaction guards are critical as they could unintentionally block all the transactions that are submitted, making the funds inside of the account using them stuck forever. - Iterating in multiple transactions guards can be not very gas efficient, although the priority order of the checks could be defined in advance.