How to Connect Substack to Gemini — via MCP

💡 No install? Use cloud.anythingmcp.com directly. Sign in, click Connectors → Substack, paste the publication's URL, and connect Gemini — done. No Docker, no git clone, no local server.

Substack + Gemini

Read a Substack publication from Gemini: posts, full-text search of the archive, comments and the RSS feed, through the same public endpoints Substack's own site uses. 7 tools, no API key and no Substack login.

What you can ask Gemini

• "What are the ten latest posts, with date and whether each one is free or paid?" Uses substack_list_posts; each post carries its audience.
• "Find every post in the archive that talks about pricing." Uses substack_search_posts.
• "Summarise post 148234567 in five bullet points." Uses substack_get_post_by_id.
• "What are readers saying under the latest post?" Uses substack_list_posts to find it, then substack_get_comments.
• "Which of this year's posts are podcast episodes?" Uses substack_list_posts; each post carries its type (newsletter, podcast or thread).
• "Give me the RSS feed so I can see what's new since Monday." Uses substack_get_rss_feed.

What you need

• The publication's base URL, for example https://lennysnewsletter.substack.com, in SUBSTACK_PUBLICATION_URL. That's all.
• No API key and no account: the connector reads public endpoints, so it sees what a logged-out visitor sees.
• One publication per connector. To read a different one, change SUBSTACK_PUBLICATION_URL.

Step 1 — Set the publication URL

1. There is no key and no Substack login. Set SUBSTACK_PUBLICATION_URL to the publication's home address, with nothing after the domain: https://yourname.substack.com or a custom domain such as https://www.lennysnewsletter.com.
2. A profile link (https://substack.com/@handle), a note link or a post link does not work. From a profile, open the publication shown there and copy the address bar up to the domain. In an app share link open.substack.com/pub/NAME/p/..., NAME is the subdomain: use https://NAME.substack.com.
3. Start with substack_list_posts (newest first, or sort=top for the most liked), then substack_get_post_by_id or substack_get_post_by_slug (the part after /p/ in a post link) for the full text. substack_find_publication_by_handle turns an @handle into the writer's publication address.

The connector reads the public JSON endpoints Substack's own site uses (Substack has no documented public API), so it sees what a signed-out visitor sees: paid posts show their preview only. Lists take limit (up to 50) and offset. A 404 on every tool means there is no publication at the configured address; an HTML page instead of JSON means the address is a profile or not a Substack site.

Step 2 — Install the adapter

On Cloud, open Connectors → Substack and paste the URL. To self-host:

curl -fsSL https://raw.githubusercontent.com/HelpCode-ai/anythingmcp/main/docker-compose.quickstart.yml -o docker-compose.yml
printf 'JWT_SECRET=%s\nENCRYPTION_KEY=%s\n' "$(openssl rand -hex 32)" "$(openssl rand -hex 32)" > .env
docker compose up -d

Step 3 — Add the connector in Gemini

Your server URL: in AnythingMCP, open MCP Servers → the server this connector is on, and copy its URL (https://cloud.anythingmcp.com/mcp/…). Use it wherever this guide shows YOUR_SERVER_ID.

Gemini CLI reads MCP servers from ~/.gemini/settings.json (or %APPDATA%\gemini\settings.json on Windows). Add:

{
  "mcpServers": {
    "anythingmcp": {
      "httpUrl": "https://cloud.anythingmcp.com/mcp/YOUR_SERVER_ID",
      "headers": { "X-API-Key": "YOUR_MCP_API_KEY" }
    }
  }
}

1. Get your MCP API key from AnythingMCP → MCP Servers → your server → API keys.
2. Save the file and restart gemini.
3. Run /mcp inside the Gemini CLI — Substack should be listed as available.
4. Vertex AI Studio: pass https://cloud.anythingmcp.com/mcp/YOUR_SERVER_ID to the tools array of your request with the same X-API-Key header.

Available tools

Troubleshooting

• Every tool fails. Check SUBSTACK_PUBLICATION_URL: it has to be the publication's home address, starting with https:// and with nothing after the domain. A profile (substack.com/@handle), note or post link does not work; open the publication from the profile and copy its address up to the domain.
• A paid post comes back cut short. The connector does not log in, so it gets what a non-subscriber gets. Paid-only content is not unlocked.
• A search returns nothing. substack_search_posts returns an empty list when no post matches. Try fewer or broader words.
• Requests start failing after many calls in a row. Substack does not publish rate limits and throttles heavy traffic. Space out bulk reads, around one request per second.

FAQ

Does Gemini 1.5 Pro or 2.x support MCP? Yes — Gemini CLI ≥ 0.4 and Vertex AI tools API both accept MCP httpUrl connectors with custom headers.

Next steps

• Connector landing page
• Connect to Claude
• Connect to ChatGPT
• Connect to Cursor
• Connect to Meta Muse