Mockzilla MCP server

@mockzilla/mcp

MCP server for Mockzilla - an open-source API mock server for OpenAPI specifications. Let Claude Code, Claude Desktop, Cursor, or Gemini CLI install Mockzilla, inspect OpenAPI specs, and spin up realistic local mock APIs in seconds. No account required for local use.

Source: github.com/mockzilla/mockzilla-mcp

Use cases

• Local API development - mock any OpenAPI spec without a real backend or sandbox account
• CI/CD integration testing - zero external dependencies in your pipeline
• PSP and payment API mocking - Stripe, PayPal, Adyen from your editor without test accounts
• Crypto exchange API mocking - Binance, Bybit without registered accounts
• Rate limit protection - develop against OpenAI, Twilio without burning quota
• Agentic workflows - let Claude or Cursor spin up and manage mock servers automatically

Two planes

@mockzilla/mcp exposes two planes of tools to your MCP client.

Local plane (no account required)

Runs on your machine. No Mockzilla account needed.

From an agent you can:

• Check whether the Mockzilla CLI is installed, and install it into a managed cache (no changes to system PATH).
• Inspect and lint an OpenAPI spec, or scan a folder for specs.
• Simplify a spec that is too heavy to mock, or pack services into a .mockz archive.
• Serve any OpenAPI spec locally as a portable mock server, and call its endpoints.
• Mock a single HTTP endpoint without a spec.
• List, stop, and clear locally managed mocks.

Hosted plane (log in once)

Ask your agent to log in, or ask for something hosted. The agent calls the login tool, your browser opens the Mockzilla login, and you pick an organization and read-only or read-and-write access. The bridge keeps the login on your machine and renews it by itself. Hosted tools are listed from the start; before you log in, the agent is told to log in first.

Agents can then:

• List deployed sims.
• Browse catalog products.
• Deploy hosted mocks from a spec, URL, or catalog bundle.
• Wait for a deploy and return the live URL.

Before logging in, only the local plane is exposed. Agents can still help users explore Mockzilla and run local mocks before they sign up.

Example prompts

You can use these directly from Claude Code, Claude Desktop, Cursor, or Gemini CLI once mockzilla is configured as an MCP server.

Local plane (no account)

• "Is the mockzilla CLI installed on this machine?"
• "Install Mockzilla for me."
• "Spin up the Petstore OpenAPI spec locally so I can curl it."
• "What endpoints does https://example.com/openapi.yaml expose?"
• "Mock POST /checkout to return a 402 response."
• "List the mock endpoints you're managing."
• "Stop the mock server you started."

Hosted plane (after logging in)

• "Log me in to Mockzilla."
• "List the sims I have deployed."
• "Show me the catalog products."
• "Deploy a Stripe mock named stripe-test and give me the live URL."
• "Create a hosted mock from this OpenAPI URL on mockzilla.org."

Install

Claude Code

One-liner, no config file editing:

claude mcp add -s user mockzilla -- npx -y @mockzilla/mcp@latest

• -s user installs for your user account (available in every project).
• Drop -s user to scope to the current project only.

Claude Desktop

Edit ~/Library/Application Support/Claude/claudedesktopconfig.json:

{
  "mcpServers": {
    "mockzilla": {
      "command": "npx",
      "args": ["-y", "@mockzilla/mcp@latest"]
    }
  }
}

Restart Claude Desktop after editing.

Cursor

Easiest: Settings -> MCP Servers -> Add new MCP server and fill in:

• Name: mockzilla
• Command: npx
• Args: -y @mockzilla/mcp@latest

Or edit ~/.cursor/mcp.json directly:

{
  "mcpServers": {
    "mockzilla": {
      "command": "npx",
      "args": ["-y", "@mockzilla/mcp@latest"]
    }
  }
}

Restart Cursor after editing.

Shortened. The full README is on GitHub.