substack-mcp

Remote MCP server that provides tools to read a Substack user's notes and recent activity when given a public profile name.

• get_user_notes: Fetch recent notes for a profile slug (for example, on or @on)
• get_user_activity: Fetch recent posts and notes, merged and sorted by date

• Node.js 18+
• A valid substack.sid cookie value (used as SUBSTACK_TOKEN)
• A reachable HTTP host/port for the MCP endpoint

This project accesses Substack data using authentication cookies and is intended only for accounts and content you are authorized to access. Make sure your use complies with Substack's terms, applicable privacy rules, and any consent requirements for the data you retrieve.

The server may use AI-assisted processing when returning or summarizing results. AI-generated output can be incomplete, inaccurate, or stale, so verify important information before relying on it.

1. Install dependencies:

   npm install

2. Create your environment file:

   cp .env.example .env

3. Set SUBSTACK_TOKEN in .env.

4. Optionally set HOST and PORT in .env.

Development mode:

npm run dev

Build and run:

npm run build
npm start

The server listens on http://0.0.0.0:3000/mcp by default and exposes a health check at /healthz.

Add this remote MCP endpoint to your client config:

{
  "mcpServers": {
    "substack": {
      "url": "http://your-host:3000/mcp"
    }
  }
}

• profile (string): Public profile slug, with or without @
• limit (number, optional): Maximum items to return (default 10, max 50)