LeanCopilot

Why we included this project

Lean Copilot brings LLM help directly into the Lean proof environment, so instead of tabbing out to a chat window you get suggestions while working. It can propose the next tactic from the current proof state, surface relevant premises from mathlib, and run a proof search for complete proofs. It ships with pretrained models from LeanDojo, and you can also attach your own models running locally or in the cloud, which matters if you need to control hardware or privacy. Because it is a Lean-native package, you add it as a dependency in your lakefile and call its APIs from inside proofs. For teams formalizing mathematics in Lean, that makes it a practical way to speed up proof development without giving up control over the models.