Which integrations are available for this server?

Provides tools for managing Substack content, including creating and updating drafts, publishing posts, uploading images, and posting short-form content to Substack Notes.

How do I use Substack MCP Server?

1. Click on "Install Server". 2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state. 3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@Substack MCP Server Create a new draft about the benefits of remote work" That's it! The server will respond to your query, and you can continue using it as needed. Here is a step-by-step guide with screenshots.

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

Go to your Substack dashboard in Chrome/Safari
Open DevTools (Cmd+Option+I or F12)
Go to Application tab → Cookies → your-substack.substack.com
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

Tool	Description
`substack_create_draft`	Create a new draft post
`substack_update_draft`	Update an existing draft
`substack_append_to_draft`	Append content (for live blogging)
`substack_add_code_block`	Add a code block to a draft
`substack_add_image`	Add an image to a draft
`substack_publish`	Publish a draft
`substack_post_note`	Post a short note
`substack_get_drafts`	List all drafts
`substack_get_posts`	List published posts
`substack_live_blog_start`	Start a live blogging session
`substack_live_blog_end`	End live blogging session

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

The core client for interacting with Substack's API.

from substack_client import SubstackClient, SubstackDocument # rate_limit is seconds between requests; timeout is per-request timeout. client = SubstackClient(token="your-sid", publication="your-pub.substack.com", rate_limit=0.5, timeout=30.0) # Upload an image img = client.upload_image("/path/to/image.png") # Returns: {"url": "https://...", "width": 800, "height": 600, "bytes": 12345, "contentType": "image/png"} # Create a document doc = SubstackDocument() doc.heading("My Post", level=2) doc.paragraph("Hello world!") doc.image(src=img['url'], width=img['width'], height=img['height'], bytes_size=img['bytes'], content_type=img['contentType']) # Create and publish draft = client.create_draft(title="My Post", body=doc) client.publish_draft(draft.id, send_email=False)

Key Technical Details

Image Node Structure

Substack uses ProseMirror and requires specific attributes for images:

{ "type": "captionedImage", "content": [{ "type": "image2", "attrs": { "src": "https://substack-post-media.s3.amazonaws.com/...", "width": 800, "height": 600, "bytes": 12345, "type": "image/png", "internalRedirect": "https://pub.substack.com/i/{draft_id}?img={encoded_url}", "belowTheFold": false, "topImage": false, "isProcessing": false } }] }

The internalRedirect field is required - without it, Substack's editor fails to render the document.

Image Handling Notes

create_draft and update_draft automatically add missing internalRedirect values for any image nodes.
Image captions are emitted as separate italic paragraphs (not imageCaption nodes) to avoid editor rendering issues.
For best rendering results, upload images through upload_image() and use the returned metadata.

Credits

Built on Jakub Slys's Substack API reverse engineering
Uses Anthropic's MCP Python SDK

License

MIT

Disclaimer

This uses Substack's unofficial/internal API which may change without notice. Use at your own risk.

Substack MCP Server

Substack MCP Server

Features

Installation

Testing

Setup

1. Get your Substack credentials

2. Create credentials file

3. Add to Claude Code

Available Tools

Usage Examples

Create a post with Claude Code

Upload and embed images

Live blogging

API Reference

SubstackClient

Key Technical Details

Image Node Structure

Image Handling Notes

Credits

License

Disclaimer

Resources

Tools

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