Creativity · Agent Protocol
Cursor Composer: Multi-File Agentic Editor
Composer is Cursor's in-IDE multi-file coding agent, rolled out in 2024 and hardened through 2025 into 'Agent mode'. Unlike single-file chat, Composer reads project context via Cursor's index, proposes edits across many files, runs terminal commands, applies diffs atomically, and iterates until tests pass. It's a staple of day-to-day software engineering workflows, sitting between inline Copilot and a fully autonomous Devin.
Protocol facts
- Sponsor
- Anysphere (Cursor)
- Status
- stable
- Spec
- https://docs.cursor.com/agent
- Interop with
- GPT, Claude, MCP, GitHub
Frequently asked questions
How is Composer different from Devin?
Composer is human-in-the-loop: the agent proposes, you accept each diff. Devin is autonomous: it owns the whole ticket and opens a PR. Cursor also offers a more autonomous 'Background Agent' that moves toward the Devin end.
Which model does Composer use?
Composer runs on user-selected frontier models (Claude Sonnet, GPT-4.1/5, Gemini 2.5) plus Cursor's own tab-completion and custom models. The agent loop, context retrieval, and diff application are Cursor's proprietary layer.
Does it support MCP?
Yes — Cursor is a first-class MCP client. You can plug in MCP servers for databases, issue trackers, or internal tools and Composer will call them as tools.
Sources
- Cursor docs — Agent — accessed 2026-04-20
- Cursor — accessed 2026-04-20