Substack MCP Server

A Model Context Protocol (MCP) server for Substack integration with Claude Code and other MCP-compatible AI tools.

Features

• Create and manage drafts - Create, update, and publish Substack posts programmatically
• Image upload - Upload images to Substack’s CDN with proper metadata
• Live blogging - Real-time post updates with timestamps
• Notes - Post short-form content to Substack Notes
• Full ProseMirror support - Proper document structure for Substack’s editor

Installation

# Clone the repo
git clone https://github.com/acolle/substack-mcp.git
cd substack-mcp

# Install dependencies
pip install -r requirements.txt

Testing

python -m unittest discover -s tests

Setup

1. Get your Substack credentials

1. Go to your Substack dashboard in Chrome/Safari
2. Open DevTools (Cmd+Option+I or F12)
3. Go to Application tab → Cookies → your-substack.substack.com
4. Find substack.sid and copy its value

2. Create credentials file

# Create ~/.substackrc
cat > ~/.substackrc << 'EOF'
export SUBSTACK_PUBLICATION="your-publication.substack.com"
export SUBSTACK_SID="your-cookie-value-here"
EOF

3. Add to Claude Code

# Add the MCP server to Claude Code
claude mcp add substack \
  --command "bash" \
  --args "-c" "source ~/.substackrc && python3 $(pwd)/substack_mcp/server.py"

Or manually add to ~/.claude.json:

{
  "mcpServers": {
    "substack": {
      "command": "bash",
      "args": ["-c", "source ~/.substackrc && python3 /path/to/substack-mcp/substack_mcp/server.py"]
    }
  }
}

Available Tools

Usage Examples

Create a post with Claude Code

You: Create a new Substack post about AI tools

Claude: I'll create a draft for you...
[Uses substack_create_draft tool]
Created draft 12345. Edit at: https://your-pub.substack.com/publish/post/12345

Upload and embed images

You: Add this diagram to my post [image path]

Claude: I'll upload the image and add it to your draft...
[Uses substack_add_image tool]
Image added successfully.

Live blogging

You: Start a live blog for the product launch

Claude: Starting live blog session...
[Uses substack_live_blog_start tool]
Live blog started. I'll append updates as they happen.

API Reference

SubstackClient