substack-mcp

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

Features

• 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

Related MCP server: substack-mcp

Requirements

• Node.js 18+

• A valid substack.sid cookie value (used as SUBSTACK_TOKEN)

• A reachable HTTP host/port for the MCP endpoint

Disclaimer

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.

Setup

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.

Run

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.

MCP Configuration Example

Add this remote MCP endpoint to your client config:

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

Tool Inputs

• profile (string): Public profile slug, with or without @

• limit (number, optional): Maximum items to return (default 10, max 500)

• startDate and endDate (optional): Inclusive/exclusive UTC date range in YYYY-MM-DD format. Supply both fields; to retrieve only 5 September 2026, use startDate: "2026-09-05" and endDate: "2026-09-06".