📌Overview

Purpose: The Everything MCP Server serves as a testing platform for developers creating MCP clients, showcasing the full capabilities of the MCP protocol.

Overview: This server is specifically designed to demonstrate various features of the MCP protocol rather than serve practical applications. It includes a range of tools, resources, and prompt capabilities to facilitate the understanding and usage of MCP.

Key Features:

• Tools: A variety of tools such as echo for message reflection, add for basic arithmetic, and longRunningOperation for simulating progress notifications are available, enabling users to explore different functionalities of MCP.

• Resource Management: The server offers 100 test resources in plaintext and binary formats, supports pagination, allows subscription to updates, and auto-refreshes resources, helping users to manage and test resource functionalities effectively.

• Prompt Handling: Supports both simple and complex prompts, with the latter allowing for advanced features like temperature settings and output styles, thus enabling more dynamic interaction scenarios.

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Everything MCP Server

This MCP server exercises all features of the MCP protocol. It is designed as a test server for MCP client developers, showcasing prompts, tools, resources, sampling, and more.

Components

Tools

1. echo
   Echoes back input messages.

   • Input:
     • message (string): Message to echo
   • Returns: Echoed text message

2. add
   Adds two numbers.

   • Inputs:
     • a (number): First number
     • b (number): Second number
   • Returns: Result of addition as text

3. longRunningOperation
   Demonstrates progress notifications during long tasks.

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

4. sampleLLM
   Demonstrates LLM sampling via MCP.

   • Inputs:
     • prompt (string): Prompt for LLM
     • maxTokens (number, default 100): Max tokens to generate
   • Returns: Generated LLM response

5. getTinyImage
   Returns a small test image as base64 encoded PNG data.

6. printEnv
   Prints all environment variables for debugging MCP server configuration.

   • Returns: JSON string of environment variables

7. annotatedMessage
   Demonstrates content annotations with metadata.

   • Inputs:
     • messageType (enum: "error", "success", "debug"): Message type
     • includeImage (boolean, default false): Include example image
   • Returns: Content with annotations based on message type and optional image
   • Example annotation for error message:

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

8. getResourceReference
   Returns a resource reference for MCP clients.

   • Input:
     • resourceId (number, 1-100): Resource ID
   • Returns: Resource reference including text introduction, embedded resource, and usage instructions

Resources

The server provides 100 test resources:

• Even numbered resources:

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

• Odd numbered resources:

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

Features:

• Pagination (10 items per page)
• Subscription to resource updates
• 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)
   • Optional arguments:
     • style (string)
   • Returns: Multi-turn conversation with images

3. resource_prompt
   Demonstrates embedding resource references in prompts.

   • Required arguments:
     • resourceId (number, 1-100)
   • Returns: Multi-turn conversation with embedded resource reference

Logging

The server sends log messages with random levels every 15 seconds, e.g.:

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

Usage with Claude Desktop

Add to your claude_desktop_config.json:

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