AT Protocol MCP Server

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Introduction ​

Welcome to the AT Protocol MCP Server documentation! This comprehensive guide will help you understand and integrate the AT Protocol ecosystem with Large Language Models (LLMs) through the Model Context Protocol (MCP).

What is AT Protocol MCP Server? ​

The AT Protocol MCP Server is a production-ready implementation that bridges the gap between LLMs and the AT Protocol ecosystem. It provides a standardized interface for LLMs to interact with decentralized social networks like Bluesky, enabling seamless integration of social networking capabilities into AI applications.

Key Features ​

Unauthenticated Mode ​

The server runs without authentication, but only a small set of public tools work in this mode. This makes it useful for:

  • Viewing public profile information
  • Inspecting social graphs and post context
  • Quick prototyping before setting up authentication

Available operations without authentication:

  • get_user_profile — view public profiles (returns additional data when authenticated)
  • get_user_connections — view social graphs via direction: 'followers' | 'follows' (richer viewer-state data when authenticated)
  • search_actors / get_author_feed — find accounts and list a user's posts
  • analyze_image — report an image blob's declared size and MIME type
  • get_post_context, find_similar_users, and other public/enhanced discovery tools

search_posts requires authentication — the AT Protocol search API changed in 2025 to require auth — so it does not work in unauthenticated mode. Most other tools also require authentication. See Authentication for setup.

Optional Authentication ​

When you need full functionality, authentication unlocks:

  • Creating, editing, and deleting posts
  • Following and unfollowing users
  • Liking and reposting content
  • Searching posts and content
  • Accessing personalized timelines and notifications
  • Viewing social graphs (followers, follows)
  • Reading threads and custom feeds
  • Managing lists and moderation settings
  • Analytics and discovery tools
  • Batch operations and advanced features

Architecture ​

The server follows a clean, modular architecture:

┌─────────────────┐
│   LLM Client    │
│  (Claude, etc)  │
└────────┬────────┘
         │
         │ MCP Protocol
         │ (JSON-RPC 2.0)
         │
┌────────▼────────┐
│  MCP Server     │
│  - Tools        │
│  - Resources    │
│  - Prompts      │
└────────┬────────┘
         │
         │ AT Protocol API
         │ (@atproto/api)
         │
┌────────▼────────┐
│  AT Protocol    │
│  - Bluesky      │
│  - Custom PDS   │
│  - Other Apps   │
└─────────────────┘

Core Concepts ​

Model Context Protocol (MCP) ​

MCP is a standardized protocol for connecting LLMs with external data sources and tools. It provides:

  • Tools: Executable functions that LLMs can call (e.g., create_post, search_posts)
  • Resources: Data sources that LLMs can read (e.g., timeline, profile, notifications)
  • Prompts: Pre-configured templates for common tasks (e.g., content composition, reply generation)

AT Protocol ​

The Authenticated Transfer Protocol (AT Protocol) is a decentralized social networking protocol that powers Bluesky and other applications. Key features include:

  • Decentralization: Users own their data and identity
  • Portability: Move between services without losing your social graph
  • Interoperability: Different apps can work with the same data
  • Open Standards: Built on open protocols and specifications

Why Use This Server? ​

For LLM Clients ​

This server is designed to be consumed by LLM clients (like Claude Desktop) via the MCP protocol:

  • Seamless Integration: Works with any MCP-compatible LLM client
  • Rich Functionality: Access to all major AT Protocol operations through natural language
  • Flexible Authentication: Works with or without authentication
  • Rate Limiting: Built-in respect for API rate limits
  • Natural Language Interface: Users interact in plain language; LLMs handle the protocol

For Developers Extending the MCP Server ​

If you want to deploy, customize, or contribute to this MCP server:

  • Type-Safe: Written in TypeScript with comprehensive type definitions
  • Well-Tested: Extensive test coverage with unit and integration tests
  • Production-Ready: Includes monitoring, logging, and error handling
  • Extensible: Easy to add custom MCP tools and resources
  • Well-Documented: Comprehensive documentation and examples
  • Modular Architecture: Clean separation of concerns for easy customization

Note: This is for developers who want to extend the MCP server itself, not for developers building applications that directly call AT Protocol APIs. If you're building a traditional application, use the official @atproto/api package directly.

For Researchers ​

If you're using LLM clients for research:

  • Public Data Access: Profile lookups, social-graph reads, and post-context tools work without authentication
  • Search: Search posts with filters via natural language (requires authentication, since the AT Protocol search API changed in 2025 to require auth)
  • Data Export: Easy access to structured social media data through LLM queries
  • Ethical: Respects user privacy and platform guidelines
  • Conversational Interface: Query data using natural language instead of code

Use Cases ​

Social Media Automation ​

Automate posting schedules, content distribution, and engagement tracking across the AT Protocol ecosystem.

Content Analysis ​

Analyze trends, sentiment, and user behavior on decentralized social networks for research or business intelligence.

Community Management ​

Manage communities, moderate content, and engage with users through AI-powered tools.

Bot Development ​

Create intelligent social media bots that can understand context and respond naturally to users.

Data Integration ​

Integrate AT Protocol data with other systems, databases, or analytics platforms.

Research & Analytics ​

Conduct social media research, track conversations, and analyze network dynamics.

Getting Started ​

Ready to dive in? Here's what to do next:

  1. Installation - Install the server and dependencies
  2. Quick Start - Get up and running in minutes
  3. Configuration - Configure the server for your needs
  4. Authentication - Set up authentication (optional)
  5. API Reference - Explore available tools and resources

Community & Support ​

License ​

This project is released under the MIT License, making it free to use, modify, and distribute.

Acknowledgments ​

This project builds on the excellent work of:

  • The AT Protocol team for creating the protocol and SDK
  • Anthropic for developing the Model Context Protocol
  • The open-source community for inspiration and contributions

Next: Learn how to install the server →