LeanIDE - IDE for Lean4

1Washington University
2California Institute of Technology
Published as part of: LeanDojo-v2, NeurIPS Mathematical Reasoning and AI, 2025

About LeanIDE

LeanIDE is the first IDE for Lean. We hope people contribute and add more features to make it better for everyone. It brings project navigation, source editing, and interactive proof development into one environment, with the goal of making Lean more approachable for formal mathematics, software verification, and scientific computing.

LeanIDE is developed as part of LeanDojo-v2 and is intended to grow through open collaboration. We welcome contributions to the editor, proof interaction, visualizations, integrations, documentation, and user experience, as well as ideas for features that would make Lean more useful to a broader community.

LeanIDE Demo


Interactive demonstration of LeanIDE's integrated development environment for formal mathematics.

Features

  • Integrated Lean workspace: Work with Lean 4 projects, source files, goals, and prover feedback in one interface.
  • AI-assisted workflows: Connect interactive proof development with the tracing, proof-search, retrieval, and progress-prediction tools in LeanDojo-v2.
  • Open and extensible: Provide a shared foundation for new editor features, research prototypes, and community-built integrations.