ATProto MCP Server

This example demonstrates a FastMCP server that provides tools and resources for interacting with the AT Protocol (Bluesky).

Features

Resources (Read-only)

atproto://profile/status: Get connection status and profile information
atproto://timeline: Retrieve your timeline feed
atproto://notifications: Get recent notifications

Tools (Actions)

post: Create posts with rich features (text, images, quotes, replies, links, mentions)
create_thread: Post multipart threads with automatic linking
search: Search for posts by query
follow: Follow users by handle
like: Like posts by URI
repost: Share posts by URI

Setup

Create a .env file in the root directory with your Bluesky credentials:

bash

[email protected]
ATPROTO_PASSWORD=your-app-password
ATPROTO_PDS_URL=https://bsky.social  # optional, defaults to bsky.social

Install and run the server:

bash

# Install dependencies
uv pip install -e .

# Run the server
uv run atproto-mcp

The Unified Post Tool

The post tool is a single, flexible interface for all posting needs:

python

async def post(
    text: str,                          # Required: Post content
    images: list[str] = None,           # Optional: Image URLs (max 4)
    image_alts: list[str] = None,       # Optional: Alt text for images
    links: list[RichTextLink] = None,   # Optional: Embedded links
    mentions: list[RichTextMention] = None,  # Optional: User mentions
    reply_to: str = None,               # Optional: Reply to post URI
    reply_root: str = None,             # Optional: Thread root URI
    quote: str = None,                  # Optional: Quote post URI
)

Usage Examples

python

from fastmcp import Client
from atproto_mcp.server import atproto_mcp

async def demo():
    async with Client(atproto_mcp) as client:
        # Simple post
        await client.call_tool("post", {
            "text": "Hello from FastMCP!"
        })
        
        # Post with image
        await client.call_tool("post", {
            "text": "Beautiful sunset! 🌅",
            "images": ["https://example.com/sunset.jpg"],
            "image_alts": ["Sunset over the ocean"]
        })
        
        # Reply to a post
        await client.call_tool("post", {
            "text": "Great point!",
            "reply_to": "at://did:plc:xxx/app.bsky.feed.post/yyy"
        })
        
        # Quote post
        await client.call_tool("post", {
            "text": "This is important:",
            "quote": "at://did:plc:xxx/app.bsky.feed.post/yyy"
        })
        
        # Rich text with links and mentions
        await client.call_tool("post", {
            "text": "Check out FastMCP by @alternatebuild.dev",
            "links": [{"text": "FastMCP", "url": "https://github.com/PrefectHQ/fastmcp"}],
            "mentions": [{"handle": "alternatebuild.dev", "display_text": "@alternatebuild.dev"}]
        })
        
        # Advanced: Quote with image
        await client.call_tool("post", {
            "text": "Adding visual context:",
            "quote": "at://did:plc:xxx/app.bsky.feed.post/yyy",
            "images": ["https://example.com/chart.png"]
        })
        
        # Advanced: Reply with rich text
        await client.call_tool("post", {
            "text": "I agree! See this article for more info",
            "reply_to": "at://did:plc:xxx/app.bsky.feed.post/yyy",
            "links": [{"text": "this article", "url": "https://example.com/article"}]
        })
        
        # Create a thread
        await client.call_tool("create_thread", {
            "posts": [
                {"text": "Starting a thread about Python 🧵"},
                {"text": "Python is great for rapid prototyping"},
                {"text": "And the ecosystem is amazing!", "images": ["https://example.com/python.jpg"]}
            ]
        })

AI Assistant Use Cases

The unified API enables natural AI assistant interactions:

"Reply to that post with these findings" → Uses reply_to with rich text
"Share this article with commentary" → Uses quote with the article link
"Post this chart with explanation" → Uses images with descriptive text
"Start a thread about AI safety" → Uses create_thread for automatic linking

Architecture

The server is organized as:

server.py - Public API with resources and tools
_atproto/ - Private implementation module
- _client.py - ATProto client management
- _posts.py - Unified posting logic
- _profile.py - Profile operations
- _read.py - Timeline, search, notifications
- _social.py - Follow, like, repost
types.py - TypedDict definitions
settings.py - Configuration management

Running the Demo

bash

# Run demo (read-only)
uv run python demo.py

# Run demo with posting enabled
uv run python demo.py --post

Security Note

Store your Bluesky credentials securely in environment variables. Never commit credentials to version control.