The Substack MCP server connects your publication to AI assistants like Claude and ChatGPT. Once connected, your assistant can read your publication data such as subscriber counts, post performance, revenue, and retention, directly in a chat, without you opening Substack or exporting a file.
Before you start
- You must be an Admin on the publication you want to connect.
- Your publication must be a Bestseller publication.
- Your AI client must support MCP (Model Context Protocol) connectors. Claude, ChatGPT, and Cursor all support this.
The Substack MCP server URL is https://mcp.substack.com/api/v1/mcp
You can add this URL as a custom connector in any MCP-compatible client. The steps below cover Claude.
Connect Claude to Substack
- Open Claude desktop or web and click Customize in the left dashboard.
- Click Connectors, then Add custom connector.
- Enter https://mcp.substack.com/api/v1/mcp in the MCP Server URL field.
- Click Add.
- Sign in to your Substack account when prompted.
- Click Allow access when Claude requests permission to read your publication data. If you have multiple publications on your Substack account, select the Bestseller publication.
- Return to Claude and start a new chat about your publication.
Note: If you try to connect an ineligible Substack publication, you’ll see an error message stating so. If you’re already signed into Substack, ensure that you’re on the account that’s linked to your Bestseller publication before connecting.
What you can ask
Once connected, you can ask your AI assistant questions about your publication directly, without opening Substack or exporting data. The assistant fetches the data through the MCP server in real time.
Examples of things you can ask:
- "What's my current subscriber count and revenue?"
- "How is my paid subscriber retention trending after 6 months?"
- "Which traffic source drove the most views on my last post?"
- "How many free subscribers have I gained since January?"
What data the Substack MCP server can access
The server provides read-only access to publication data such as dashboard metrics, traffic data, and publication settings. It cannot publish posts, send Notes, or modify your account.
The server cannot access profile data or Notes activity. If you ask the AI assistant for stats on your Notes activity, it will not be able to return them.