MCP Server Official reference

Everything

A reference MCP server that exercises protocol features (prompts, tools, resources, sampling) so MCP client builders can test against it.

npm install -g @modelcontextprotocol/server-everything@latest
Everything preview image

What it is

The Everything MCP server attempts to exercise all the features of the MCP protocol. It is explicitly not intended to be a useful server, but a test server for builders of MCP clients. It implements prompts, tools, resources, sampling, and more to showcase MCP capabilities, and supports stdio, SSE, and streamable HTTP transports.

Who it's for

  • Builders of MCP clients who need a server to test against
  • Developers who want to see MCP protocol primitives demonstrated

Requirements

Requirements

  • npx (used to launch @modelcontextprotocol/server-everything)
  • npm (needed to install and run from source)
  • Docker (only for the Docker-based VS Code install option)

Setup

  1. Claude Desktop (stdio)

    Add this to your claude_desktop_config.json.

    json
    {
      "mcpServers": {
        "everything": {
          "command": "npx",
          "args": [
            "-y",
            "@modelcontextprotocol/server-everything"
          ]
        }
      }
    }
  2. Claude Desktop on Windows

    On Windows, use cmd /c to launch npx.

    json
    {
      "mcpServers": {
        "everything": {
          "command": "cmd",
          "args": [
            "/c",
            "npx",
            "-y",
            "@modelcontextprotocol/server-everything"
          ]
        }
      }
    }
  3. VS Code (NPX)

    Add to your user mcp.json (via the Command Palette, MCP: Open User Configuration) or to .vscode/mcp.json in your workspace.

    json
    {
      "servers": {
        "everything": {
          "command": "npx",
          "args": ["-y", "@modelcontextprotocol/server-everything"]
        }
      }
    }
  4. Install as a global package

    Install the package globally, then run it with npx.

    bash
    npm install -g @modelcontextprotocol/server-everything@latest

Examples

Run the default stdio server

shell
shell
npx @modelcontextprotocol/server-everything

What it does: Runs the server with the default stdio transport.

Run the SSE server

shell
shell
npx @modelcontextprotocol/server-everything sse

What it does: Starts the server using the SSE transport, which is deprecated as of 2025-03-26.

Run the streamable HTTP server

shell
shell
npx @modelcontextprotocol/server-everything streamableHttp

What it does: Starts the server using the Streamable HTTP transport.

Run streamable HTTP from source

shell
shell
cd src/everything
npm install
npm run start:streamableHttp

What it does: Runs the server from a source checkout instead of the installed package.

Pros & cons

Pros

  • Pro:Exercises a broad set of MCP features, including prompts, tools, resources, and sampling
  • Pro:Supports stdio, SSE, and streamable HTTP transports for testing different client setups
  • Pro:Easy to launch via npx, with documented configs for Claude Desktop and VS Code
  • Pro:MIT licensed

Cons

  • Con:Not intended to be a useful server; it is only for testing
  • Con:SSE transport is deprecated as of 2025-03-26
  • Con:The full list of tools, resources, and prompts is in a separate features document, not the README

Images