Tractor is a system integrated into Beanstalk that allows for generalized sequences of instructions to be encoded, using EIP-712 signing and verification, on the EVM. The core of the code outlined here can be trivially expanded for use with any protocol.
An example of the system being expanded with protocol-specific functionality can be seen in Beanstalk. I led this integration and the relevant files are visible here.
- https://github.com/BeanstalkFarms/Beanstalk/blob/master/protocol/contracts/libraries/LibTractor.sol
- https://github.com/BeanstalkFarms/Beanstalk/blob/master/protocol/contracts/beanstalk/farm/TractorFacet.sol
- https://github.com/BeanstalkFarms/Beanstalk/blob/master/protocol/test/foundry/farm/Tractor.t.sol