What's the "RCP Server" option in the Beta settings?

Discussion
1

Does anyone have information about the new “RCP Server” option in the Beta settings?

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*EDIT Oops, wrong acronym. :man_facepalming:

Remote Procedure Call, but how, why, or when to use it with Cursor isn’t obvious to me.

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Thanks for the info @AbleArcher. I came across this when searching online for more info…

RCP Server lets external clients connect into your running Cursor instance…

Purpose: Exposes your active Cursor workspace and editor context (open files, selections, ASTs) over a local network endpoint so external tools-such as custom CLIs, language servers, or IDE plugins-can query and manipulate your code in real-time.

  • Transport: Runs as an HTTP/WebSocket server on a configurable port (e.g., localhost:XXXX), allowing bi-directional communication with connected clients.

  • Configuration: Enabled via the new “Enable RCP Server” toggle in Cursor’s settings. You can specify the listening port and set access tokens for authentication.

  • Usage: External applications initiate an RCP session by connecting to the server endpoint, subscribing to file-change events, sending edits or commands, and receiving live updates from Cursor.

I don’t know how reliable this information is, but here’s some more…

Cursor IDE lets you turn your running workspace into a Remote Cursor Protocol (RCP) server so that external clients can connect to and manipulate that specific project. To enable and configure an RCP server on a per-project basis, you’ll use the IDE’s Settings UI and persist those settings into a project-local config file.

1. Enable RCP Server in Project Settings

Open the target project in Cursor and then:

  • Go to Settings → Features → RCP Server

  • Flip Enable RCP Server to On

2. Configure Port and Authentication

With RCP enabled, specify:

  • Port: Choose any free TCP port (e.g. 5478) on which Cursor will listen.

  • Access Token (optional): Generate or paste a token to require clients to authenticate before they can connect.

3. Persist Configuration to the Project

To tie the RCP settings specifically to this project, save them into a .cursor/rcp.json file in your project root. Click Save to Project (if available), or create the file yourself with entries like:

{
  "rcpServer": {
    "enabled": true,
    "port": 5478,
    "authToken": "your-secure-token"
  }
}

This ensures anyone who clones the repo and opens it in Cursor will inherit the same RCP settings.

4. Restart Cursor

Close and reopen the project (or restart the IDE) so that Cursor picks up the new .cursor/rcp.json and starts the RCP server automatically on your specified port.

You’ve now set up a project-scoped RCP server that external tools can connect to without affecting other Cursor workspaces.

Cursor’s Remote Cursor Protocol (RCP) Server turns your live Cursor workspace into a programmable service that external tools can query and control. Below are several real-world scenarios where enabling an RCP server can streamline workflows, automate tasks, and integrate Cursor with your existing toolchain.

Use Case Examples

  • Custom IDE Extensions and Plugins
    Build lightweight plugins or extensions for editors like VS Code or Vim that connect over WebSocket to your Cursor RCP server. These can synchronize selections, jump to definitions, or inject code snippets in real time without requiring deep integration into Cursor’s core.

  • Automated Code Review Bots
    Deploy a bot that listens for pull request events and uses the RCP server to fetch the latest file contents, run static analysis, annotate issues directly in the editor buffer, and push review comments back to your Git platform.

  • Live Collaboration and Pair Programming
    Create a custom collaboration layer that streams file-change events and cursor positions from one developer’s Cursor instance to another’s. Participants can subscribe to each other’s edits and view real-time code updates via the RCP API.

  • CI/CD Integration for Dynamic Testing
    Hook your continuous integration pipeline into Cursor by connecting to the RCP server to run targeted tests or linters on specific file changes. Test results and coverage reports can be reflected immediately in the active editor session.

  • Automated Refactoring Scripts
    Write standalone Node.js or Python scripts that connect to the RCP server, traverse the abstract syntax tree (AST) of your project, perform batch renames or API migrations, and commit the changes back into the open workspace without manual intervention.

  • Documentation Generators and Live Previews
    Integrate Cursor with documentation frameworks by subscribing to file updates and regenerating Markdown or HTML previews on the fly. Your documentation server can fetch the latest code from Cursor via RCP and serve up-to-date API references or code snippets.

By exposing your Cursor environment over HTTP/WebSocket, the RCP server enables seamless two-way integration with external systems-empowering custom tooling, collaboration platforms, CI/CD pipelines, and automated workflows to interact directly with your live codebase.

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Where did you find this? Got a link?

5

Got it from Perplexity results, that’s why I’m not sure about the reliability

6

Sounds interesting if true, but I have no idea where Perplexity would be getting that from since most results redirect to RPC and the only thing I could really find for RCP is a deprecated remote copy protocol…

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Came here for info .. seems like remote controlled cursor instance - like from ssh.

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There is no info in the Docs, neither in the Changelog about this feature, so we can only guess :grin:

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It is very likely it is needed for the background agent

11

Have you succeeded? I tried but there was no response

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I just updated to Version: 0.50.3 and noticed that the “Enable RCP Server” setting isn’t there anymore.

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I did see “Open RCP Console” in the command palette though…

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It’s a setting for background agents :slight_smile:

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How to use it

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This feature is still in early testing, not yet available to all beta testers. Cursor team has announced it but will make it public once they test with more users and improve it.

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Hi @T1000, were the Perplexity results in the post reply above correct at all for what the RCP server is?

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Perplexity answered what a rcp server is and connected that answer with Cursor based on the request. While Cursor had that RCP Server setting, its likely for Background Agent communication as it has to send the completed changes back to Cursor editor. I have not yet seen any such docu, but you could ask it for the source where it got that info from :slight_smile: