Everything MCP Server

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

• echo
  • Simple tool to echo back input messages
  • Input:
    • message (string): Message to echo back
  • Returns: Text content with echoed message
• add
  • Adds two numbers together
  • Inputs:
    • a (number): First number
    • b (number): Second number
  • Returns: Text result of the addition
• 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
• 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
• getTinyImage
  • Returns a small test image
  • No inputs required
  • Returns: Base64 encoded PNG image data
• printEnv
  • Prints all environment variables
  • Useful for debugging MCP server configuration
  • No inputs required
  • Returns: JSON string of all environment variables
• 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"]
  }

  Copy

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

• simple_prompt
  • Basic prompt without arguments
  • Returns: Single message exchange
• 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

Logging

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

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

Usage with Claude Desktop

Add to your claude_desktop_config.json:

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