Using REA with Claude Code, Cursor, Codex and other agents
- Officially listed agents: Claude Code, Codex, Cursor, Gemini CLI, Grok Build.
- Any other client that supports local MCP servers can register REA manually.
- Registration is done by
npx rea-agents setup— no hand-editing needed for listed agents.
How REA plugs into an agent
REA is an MCP (Model Context Protocol) server that runs locally. During setup you select which agents to register; REA adds itself to each agent’s MCP configuration and installs matching workflow instructions so the agent knows how to run an investigation. After a restart, the agent can call REA’s tools directly.
Each tool result includes evidence, limitations and unknowns. REA also offers guided MCP prompts and investigation sessions.
Set up REA for Claude Code or Cursor
- Run setup
npx rea-agents setup - Select your agent
Tick Claude Code, Cursor, Codex, Gemini CLI or Grok Build. Review and approve the changes. - Restart the agent
Close and reopen the client so it loads the new MCP server. - Prompt it
For example, the README’s template: “Understand how search works in the Notes app, show me the evidence, and build a similar feature for my project.” Replace the app and feature with your own target.
Other MCP clients
The README says other MCP-capable clients can use manual MCP registration and points to the MCP registry section of the project’s installation guide for the details. We don’t reproduce a config snippet here because the README itself does not include one — use the official docs.
Prompting tips from early testers
From Kingy AI’s reproducible test of REA:
- Start with one feature that has observable output, not “clone this whole app”.
- Pin the exact REA version and treat any change in output as a new test.
- Keep the original artifact, hashes, raw analysis and trace output.
- Inspect the cited source locations and write down the behaviour before reimplementing.
- Test edge cases — delimiters, coercion, boundaries, failure paths — that would expose a wrong explanation.
FAQ
Does REA work with Claude Code?
Yes, Claude Code is the first agent listed in the README.
Does REA send my binaries to the model?
REA analyzes targets locally. The findings it returns go to your agent, so they fall under your model provider’s data policy.
Which agent is best for REA?
The project does not recommend one. Kingy AI’s test used Codex; Cyber Security News’ coverage focuses on Claude Code and Cursor.
Unofficial, independent guide. Not affiliated with the REA project or its author (morluto). The official source is github.com/morluto/rea. Only analyze software you own or are authorized to examine.