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