vercel-deployment-mcp

A reference Model Context Protocol server for observing Vercel projects and deployments over stdio.

This is a community reference implementation focused on deployment-workflow patterns. It is not a replacement for Vercel's own MCP offering. Its purpose is to demonstrate, in a small and readable codebase, how a deployment-focused MCP server can handle configuration cleanly and behave predictably on short-lived infrastructure.

Tools

list_projects and list_deployments each return a single page of up to limit results (default 20, max 100). There is no cursor pagination; narrow the request with search, projectId, or state to see more specific results.

Install

From npm:

npm install @addiplus/vercel-deployment-mcp

Or run it directly without installing:

npx @addiplus/vercel-deployment-mcp

From source:

git clone https://github.com/addiplus/vercel-deployment-mcp.git
cd vercel-deployment-mcp
npm install
npm run build
npm test

Building and testing this repo requires Node 22+ (CI runs 22 and 24); the published package runs on Node >=18 per engines.

Configuration

On an HTTP 429 with a numeric Retry-After header of 10 seconds or less, the server waits that long and retries the request once; any other 429 is surfaced as an error on the first attempt.

Example client configuration (Claude Desktop / Claude Code):

{
  "mcpServers": {
    "vercel-deployment": {
      "command": "npx",
      "args": ["-y", "@addiplus/vercel-deployment-mcp"],
      "env": { "VERCEL_TOKEN": "…" }
    }
  }
}

When running from a source checkout, use "command": "node" with "args": ["/path/to/vercel-deployment-mcp/dist/index.js"] instead.

Design principles

Dated 2026-07-10. Each claim below is implemented in code and verified by the test suite where testable (test/); design properties cite the implementing code.

1. Configuration values never appear in output. The access token is read only from the environment. Error messages are shaped, size-bounded, and passed through a redaction guard so upstream API messages cannot echo the value back (src/vercel.ts).
2. stdout belongs to the protocol. All diagnostics go to stderr (src/index.ts), so no log line can leak into a tool response.
3. Minimal footprint. v0.1 tools are read-only observations of projects and deployments; the server requests nothing beyond what those reads need.
4. Stateless by design. Configuration is re-read from the environment on every tool call (verified in test/tools.test.ts), so behavior is identical on long-lived hosts and short-lived workers. The one piece of module-level state is a request throttle (src/vercel.ts) that spaces out and caps concurrent Vercel API calls; its interval and concurrency settings are read once at first use, and it holds no credentials or response data.

Roadmap

• Deployment actions with an explicit out-of-band approval step (exploring the patterns discussed in MCP spec issues #2919/#2920 around multi-round tool results on stateless transports).
• Standardizing how server.json describes stdio package install manifests and how clients convert them into local configuration files (spec issue #2963, registry issue #749).

License

MIT