LGTM - AI Code Review

LGTM is a Visual Studio Code extension that uses GitHub Copilot Chat to review source code changes in Git. It can help you catch bugs, areas for improvement, and other issues before merging.

Getting Started

Start a Review Switch to the Chat sidebar.

• Type /review to review uncommitted changes or changes between two branches, commits, or tags.
• You can specify git refs explicitly, e.g. /review develop main, or omit arguments to select refs interactively.
• Use /branch to review changes between two branches.
• Use /commit to review a single commit.

View Results

LGTM will respond with review comments grouped by file and sorted by severity.

Use in Agent Mode

LGTM is also available in agent mode, so you can include it as part of your worklflow. For example, you might ask the agent to Review the current changes using #reviewStaged and fix any severe issues. Assuming you have staged changes, the agent will start a review using LGTM and then act on the review comments. Consider specifying the severity of issues to fix, e.g. ... and fix any issues with severity >= 3.

Features

• Only Copilot Required: Uses Copilot Chat for reviewing changes.
• Model Selection: Choose other language model available to VS Code via the LGTM: Select Chat Model command available in the Command Palette (press Cmd+Shift+P or Ctrl+Shift+P).
• Custom Instructions: Add custom instructions via the Lgtm: Custom Prompt setting (e.g., change the language of review comments by adding - In the final JSON output, use Spanish for the comment field.).
• Agent Support: Adds tools to enable automatic reviews in agent mode:
  • #review: Reviews changes between two git references (branches, tags, or commits)
  • #reviewStaged: Reviews only staged changes in your working directory
  • #reviewUnstaged: Reviews only unstaged changes in your working directory
  • Example usage: After your changes, run all tests and run #reviewUnstaged to check your work.
• Chat Integration: Review content remains in chat history for follow-up questions by omitting @lgtm.

Limitations

• This project is a work in progress; comment quality may vary.
• Large change sets may trigger chat model rate limits. Please wait before retrying.
• Some non-Copilot models require setting a system prompt which is not possible just yet.

Data Usage

Source code changes and commit messages selected for review are sent to the chat model configured in the extension settings (default: GitHub Copilot GPT-4.1).

Contributing

Contributions are welcome! If you have ideas, bug reports, or want to help improve LGTM, please open an issue or submit a pull request on GitHub.