ActivityPub MCP Server is a comprehensive MCP server that enables LLMs to explore and interact with the Fediverse through standardized MCP tools, resources, and prompts. It provides a Fediverse Client to talk to ActivityPub servers (Mastodon, Pleroma, Misskey, etc.), WebFinger discovery to locate actors across the network, and a full MCP protocol implementation with read-only Resources, Tools, and Prompts. The server is optimized for LLM interaction patterns and is fully typed in TypeScript with modern ESM. It includes monitoring, health checks, and performance metrics, supporting cross-platform operation on Windows, macOS, and Linux. The project ships with installation scripts, environment configuration, and documentation, and can be tested with the MCP Inspector. Claude Desktop integration is supported via a configuration entry. The architecture emphasizes modular components for WebFinger, remote ActivityPub clients, instance discovery, and data retrieval, enabling LLMs to discover remote actors, timelines, instances, and search across the Fediverse using a complete MCP stack.