everything
Overview
The everything-mcp-server is a reference and demonstration Model Context Protocol (MCP) server that exposes a broad collection of example tools in a single implementation. It’s designed to showcase how MCP works end-to-end by providing many different tool types — spanning data access, computation, state, and side effects — that AI assistants can call during a workflow.
This server is primarily used for learning, testing, debugging, and validating MCP clients, rather than integrating with a specific external service.
Transport
stdio
Tools
Key Capabilities
- Comprehensive MCP showcase — Demonstrates many types of MCP tools in one server.
- Client development and testing — Ideal for verifying MCP client implementations and tool-calling behavior.
- End-to-end debugging — Test request/response handling, streaming, and error cases in a controlled environment.
- Stateful and stateless examples — Includes tools that return static values, compute results, or interact with local state.
- Reference implementation — Serves as a practical example for building custom MCP servers.
How It Works
The everything-mcp-server runs as a local MCP service and registers a large set of example tools when it starts. Each tool is implemented with simple, predictable behavior so that MCP clients can easily test tool discovery, invocation, argument passing, and response handling.
When an AI assistant invokes a tool, the server executes the corresponding handler and returns structured results over the MCP protocol. Because the tools are intentionally simple and varied, the server is useful for exercising nearly every aspect of an MCP client without relying on external APIs or credentials.
This makes the Everything MCP server ideal for onboarding, education, protocol validation, and regression testing, as well as a starting point for developers who want to understand how to build their own MCP servers.