@modelcontextprotocol/server-everything

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

• printEnv

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

• 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

• 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"]
    }
    

• 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

• 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.

• structuredContent

• Demonstrates a tool returning structured content using the example in the specification
• Provides an output schema to allow testing of client SHOULD advisory to validate the result using the schema
• Inputs:
  • location (string): A location or ZIP code, mock data is returned regardless of value
• Returns: a response with
  • structuredContent field conformant to the output schema
  • A backward compatible Text Content field, a SHOULD advisory in the specification

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

• 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