Devvit

Devvit MCP Server is a companion runtime that lets you write and run applications on Reddit’s developer platform. It exposes your code to the MCP ecosystem, enabling you to build, test, and deploy integrations with standard MCP tooling and workflows.

How to use

You connect to the Devvit MCP Server from your MCP client by configuring it as a local, stdio-based server. This runs your MCP code in the same process space as your editor or tooling, making iteration fast and interactive. Use the standard MCP client workflow to start, test, and debug your apps, keeping telemetry off if you prefer.

How to install

Prerequisites you need before installing: Node.js and npm (Node Package Manager). Ensure you have npm and npx accessible from your shell.

{
  "mcpServers": {
    "devvit_mcp": {
      "command": "npx",
      "args": ["-y", "@devvit/mcp"]
    }
  }
}

Opting out Of Telemetry

If you want to disable telemetry while using the MCP server, add the environment variable DEVVIT_DISABLE_METRICS and set it to true in the same configuration.

{
  "mcpServers": {
    "devvit_mcp": {
      "command": "npx",
      "args": ["-y", "@devvit/mcp"],
      "env": {
        "DEVVIT_DISABLE_METRICS": "true"
      }
    }
  }
}

Developing on the MCP Server

To develop and run the MCP server locally, follow these steps to clone the project, install dependencies, and start the dev server.

git clone git@github.com:reddit/devvit-mcp.git

cd devvit-mcp

nvm use

npm install

npm run dev

If you want to test your MCP server inside of other projects, you can pass the full path to your node runtime and the location of /dist/index.js on your machine. Use the Node path from which node is executed and the dist path relative to your repo root:

• Node path: which node
• Dist: pwd from the root of your devvit-mcp + /dist/index.js

{
  "mcpServers": {
    "devvit_mcp": {
      "command": "/Users/your_user/.nvm/versions/node/vXX.X.X/bin/node",
      "args": ["/path/to/your/devvit-mcp/dist/index.js"]
    }
  }
}

MCP Gotchas

Avoid placing console.log in the hot path of your app during debugging, as it can produce confusing JSON parsing messages. The logger is shimmed to convert non-JSON log output into valid JSON automatically.

Only log to console.error from your MCP when you are running through MCP to keep logs clean and focused on real errors.

Debugging

For an optimal debugging experience, run npm run dev, navigate to Tools, list the available tools, and trigger them to observe live behavior and logs.

If you encounter a server capability error like “Server does not support logging (required for notifications/message)”, you need to add the missing capability to your new MCPServer by following the guidance for the required capability key.

Versioning

Versioning for this package is automated by CI/CD. The version field in package.json is a placeholder and will be updated during the release process. Check the git tags for the actual released versions.

Credits

This work draws inspiration from open-source MCP server designs. Consider leveraging related libraries when you need additional docs servers.