rn-upgrade-helper-mcp

An MCP server for React Native Upgrade Helper diffs.

It fetches the same generated template diffs used by React Native Upgrade Helper, backed by react-native-community/rn-diff-purge, and exposes them as MCP tools that agents can call directly.

Tools

• get_upgrade_helper_url: builds the web Upgrade Helper URL.
• list_changed_files: returns structured changed-file metadata.
• get_file_diff: returns the diff for one file.
• get_upgrade_diff: returns the full diff, optionally filtered by android, ios, or js.
• summarize_upgrade: summarizes changed areas and notable files.

Local Development

npm install
npm run build
node dist/index.js

Codex Plugin Usage

This repo can also be installed as a Codex plugin because it contains:

• .codex-plugin/plugin.json
• .mcp.json
• a bundled dist/index.js

Build before committing/publishing:

npm install
npm run build

Then push the repo to GitHub. Users can install the plugin from the GitHub repo in Codex.

Client Integrations

This repo includes ready-to-copy MCP config snippets for:

• OpenAI Codex
• Codex plugin wrapper
• Cursor
• Claude Desktop
• Claude Code
• Windsurf / Cascade
• Cline
• VS Code / GitHub Copilot Agent Mode

See docs/CLIENTS.md.

Direct MCP Client Config

After publishing to npm:

{
  "mcpServers": {
    "rn-upgrade-helper": {
      "command": "npx",
      "args": ["-y", "rn-upgrade-helper-mcp"]
    }
  }
}

For local testing from this repo:

{
  "mcpServers": {
    "rn-upgrade-helper": {
      "command": "node",
      "args": ["/absolute/path/to/rn-upgrade-helper-mcp/dist/index.js"]
    }
  }
}

Example Inputs

Example upgrade request:

{
  "from": "0.73.9",
  "to": "0.79.2",
  "appName": "MyApp",
  "packageName": "com.example.myapp"
}

Publishing

npm install
npm run build
npm publish --access public

If publishing under an internal scope, rename the package first:

{
  "name": "@your-scope/rn-upgrade-helper-mcp"
}

Then update the MCP client config to use the scoped package name.

Notes

• The server requires Node 18.18+ because it uses native fetch.
• Diffs are fetched from:
  • https://raw.githubusercontent.com/react-native-community/rn-diff-purge/diffs/diffs/<from>..<to>.diff
  • fallback: https://github.com/react-native-community/rn-diff-purge/compare/release/<from>..release/<to>.diff
• Package name and app name are applied by replacing com.rndiffapp, com/rndiffapp, and RnDiffApp in the generated template diff.