MCPClientMock

mockserver-mcp

An MCP (Model Context Protocol) server for interacting with James Bloom's MockServer. This enables AI assistants to create mock HTTP expectations, verify requests, clear state, and manage MockServer instances programmatically.

Prerequisites

You need a running MockServer instance:

# Using Docker (easiest)
docker run -d -p 1080:1080 mockserver/mockserver

Installation

Using npx (recommended)

npx mockserver-mcp

Global installation

npm install -g mockserver-mcp
mockserver-mcp

Configuration

Environment Variables

Variable	Description	Default
MOCKSERVER_HOST	MockServer hostname	localhost
MOCKSERVER_PORT	MockServer port	1080

MCP Client Configuration

Add to your MCP client configuration file (e.g., Claude Desktop, Kiro, Cursor):

{
  "mcpServers": {
    "mockserver": {
      "command": "npx",
      "args": ["-y", "mockserver-mcp"],
      "env": {
        "MOCKSERVER_HOST": "localhost",
        "MOCKSERVER_PORT": "1080"
      }
    }
  }
}

For shared team MockServer, change MOCKSERVER_HOST to your server's address.

Available Tools

mockserver_create_expectation

Create a mock HTTP expectation on MockServer.

Parameters:

• httpRequest (required): Request matching criteria
  • method: HTTP method (GET, POST, PUT, DELETE, etc.)
  • path: URL path to match
  • queryStringParameters: Query parameters to match
  • headers: Headers to match
  • body: Body matcher with type (STRING, JSON, REGEX, XPATH, JSON_PATH) and value
• httpResponse: Response configuration
  • statusCode: HTTP status code
  • headers: Response headers
  • body: Response body (string or object)
  • delay: Response delay with timeUnit and value
• times: How many times to match (remainingTimes, unlimited)
• timeToLive: Expectation lifetime (timeUnit, timeToLive)

Example:

{
  "httpRequest": {
    "method": "GET",
    "path": "/api/users"
  },
  "httpResponse": {
    "statusCode": 200,
    "body": { "users": [] }
  }
}

mockserver_verify

Verify that requests matching criteria were received by MockServer.

Parameters:

• httpRequest (required): Request matching criteria (same as create_expectation)
• times: Expected request count
  • atLeast: Minimum number of requests
  • atMost: Maximum number of requests
  • exactly: Exact number of requests

Example:

{
  "httpRequest": {
    "method": "POST",
    "path": "/api/orders"
  },
  "times": {
    "atLeast": 1
  }
}

mockserver_clear

Clear expectations and recorded requests from MockServer.

Parameters:

• httpRequest (optional): Request matcher to clear specific expectations. If not provided, clears all.

Example:

{
  "httpRequest": {
    "path": "/api/users"
  }
}

mockserver_reset

Perform a full reset of MockServer, clearing all expectations and recorded requests.

Parameters: None

mockserver_retrieve_requests

Retrieve recorded requests from MockServer.

Parameters:

• httpRequest (optional): Request matcher to filter recorded requests

Example:

{
  "httpRequest": {
    "method": "GET"
  }
}

mockserver_status

Get MockServer connection status and configuration.

Parameters: None

Why Mocking?

API mocking enables early testing — start building and testing your frontend or integrations before the backend is ready. No more waiting. Ship faster.

Requirements

• Node.js >= 18.0.0
• A running MockServer instance

Links

• npm: https://www.npmjs.com/package/mockserver-mcp
• GitHub: https://github.com/Akkshay10/MCPClientMock
• MCP Registry: https://registry.modelcontextprotocol.io

License

MIT