What is Cursor's Composer feature and how do I use it?
What Composer does
Composer goes beyond single-file suggestions by letting you make coordinated changes across multiple files. For example, you can ask it to 'add a new API endpoint and update the frontend to call it', and it will propose edits to relevant files. It's like having an AI pair programmer that can handle broader tasks.
Composer is accessible via a keyboard shortcut (Ctrl+I or Cmd+I) or through the Command Palette. When you open it, you'll see a chat-like interface where you describe what you want. The AI then generates a plan and shows you diffs of the proposed changes.
How to use it effectively
Start by giving a clear, specific instruction. For instance, 'Refactor the login function to use async/await and add error handling.' Composer will analyze your codebase and suggest edits. You can review each change and accept or reject them individually or all at once.
For best results, ensure your project is indexed so Composer understands the full context. You can also iterate: if the first attempt isn't perfect, reply with follow-up instructions to refine the changes.
- Open with Ctrl+I or Cmd+I.
- Describe changes in plain English.
- Review diffs before applying.
- Iterate with follow-up messages.
Common mistakes
- Using Composer for tiny edits that are faster to do manually.
- Not reviewing the proposed changes carefully, leading to unintended modifications.
- Forgetting to save or commit before using Composer, making it harder to revert if needed.
