Everything MCP Server

This MCP server attempts to exercise all the features of the MCP protocol. It is not intended to be a useful server, but rather a test server for builders of MCP clients. It implements prompts, tools, resources, sampling, and more to showcase MCP capabilities.

Components

Tools

1. echo

   • Simple tool to echo back input messages
   • Input:
     • message (string): Message to echo back
   • Returns: Text content with echoed message

2. add

   • Adds two numbers together
   • Inputs:
     • a (number): First number
     • b (number): Second number
   • Returns: Text result of the addition

3. longRunningOperation

   • Demonstrates progress notifications for long operations
   • Inputs:
     • duration (number, default: 10): Duration in seconds
     • steps (number, default: 5): Number of progress steps
   • Returns: Completion message with duration and steps
   • Sends progress notifications during execution

4. sampleLLM

   • Demonstrates LLM sampling capability using MCP sampling feature
   • Inputs:
     • prompt (string): The prompt to send to the LLM
     • maxTokens (number, default: 100): Maximum tokens to generate
   • Returns: Generated LLM response

5. getTinyImage

   • Returns a small test image
   • No inputs required
   • Returns: Base64 encoded PNG image data

6. printEnv

   • Prints all environment variables
   • Useful for debugging MCP server configuration
   • No inputs required
   • Returns: JSON string of all environment variables

7. annotatedMessage

   • Demonstrates how annotations can be used to provide metadata about content
   • Inputs:
     • messageType (enum: "error" | "success" | "debug"): Type of message to demonstrate different annotation patterns
     • includeImage (boolean, default: false): Whether to include an example image
   • Returns: Content with varying annotations:
     • Error messages: High priority (1.0), visible to both user and assistant
     • Success messages: Medium priority (0.7), user-focused
     • Debug messages: Low priority (0.3), assistant-focused
     • Optional image: Medium priority (0.5), user-focused
   • Example annotations:

     {
       "priority": 1.0,
       "audience": ["user", "assistant"]
     }
     

8. getResourceReference

   • Returns a resource reference that can be used by MCP clients
   • Inputs:
     • resourceId (number, 1-100): ID of the resource to reference
   • Returns: A resource reference with:
     • Text introduction
     • Embedded resource with type: "resource"
     • Text instruction for using the resource URI

9. startElicitation

   • Initiates an elicitation (interaction) within the MCP client.
   • Inputs:
     • color (string): Favorite color
     • number (number, 1-100): Favorite number
     • pets (enum): Favorite pet
   • Returns: Confirmation of the elicitation demo with selection summary.

Resources

The server provides 100 test resources in two formats:

• Even numbered resources:

  • Plaintext format
  • URI pattern: test://static/resource/{even_number}
  • Content: Simple text description

• Odd numbered resources:

  • Binary blob format
  • URI pattern: test://static/resource/{odd_number}
  • Content: Base64 encoded binary data

Resource features:

• Supports pagination (10 items per page)
• Allows subscribing to resource updates
• Demonstrates resource templates
• Auto-updates subscribed resources every 5 seconds

Prompts

1. simple_prompt

   • Basic prompt without arguments
   • Returns: Single message exchange

2. complex_prompt

   • Advanced prompt demonstrating argument handling
   • Required arguments:
     • temperature (number): Temperature setting
   • Optional arguments:
     • style (string): Output style preference
   • Returns: Multi-turn conversation with images

3. resource_prompt

   • Demonstrates embedding resource references in prompts
   • Required arguments:
     • resourceId (number): ID of the resource to embed (1-100)
   • Returns: Multi-turn conversation with an embedded resource reference
   • Shows how to include resources directly in prompt messages

Logging

The server sends random-leveled log messages every 15 seconds, e.g.:

{
  "method": "notifications/message",
  "params": {
	"level": "info",
	"data": "Info-level message"
  }
}

Usage with Claude Desktop (uses stdio Transport)

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "everything": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-everything"
      ]
    }
  }
}

Usage with VS Code

For quick installation, use of of the one-click install buttons below...

For manual installation, add the following JSON block to your User Settings (JSON) file in VS Code. You can do this by pressing Ctrl + Shift + P and typing Preferences: Open User Settings (JSON).

Optionally, you can add it to a file called .vscode/mcp.json in your workspace. This will allow you to share the configuration with others.

Note that the mcp key is not needed in the .vscode/mcp.json file.

NPX

{
  "mcp": {
    "servers": {
      "everything": {
        "command": "npx",
        "args": ["-y", "@modelcontextprotocol/server-everything"]
      }
    }
  }
}

Running from source with HTTP+SSE Transport (deprecated as of 2025-03-26)

cd src/everything
npm install
npm run start:sse

Run from source with Streamable HTTP Transport

cd src/everything
npm install
npm run start:streamableHttp

Running as an installed package

Install

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

Run the default (stdio) server

npx @modelcontextprotocol/server-everything

Or specify stdio explicitly

npx @modelcontextprotocol/server-everything stdio

Run the SSE server

npx @modelcontextprotocol/server-everything sse

Run the streamable HTTP server

npx @modelcontextprotocol/server-everything streamableHttp