Open source. Free forever.

Install the Mockzilla CLI

Turn any OpenAPI spec into a live mock server in seconds. Pick the install method that fits your machine.

The Mockzilla CLI is MIT-licensed and runs offline. Cloud features like hosted simulations and shared catalogs are opt-in.

$brew tap mockzilla/tap
$brew install mockzilla

macOS and Linux. Tap the formula and install.

Run your first mock

Point Mockzilla at any OpenAPI spec, by URL or path, and you have a live simulation on port 2200.

Try one of these specs:

$mockzilla https://petstore3.swagger.io/api/v3/openapi.json
$mockzilla https://raw.githubusercontent.com/github/rest-api-description/main/descriptions/api.github.com/api.github.com.json

Use Mockzilla from your AI agent

Mockzilla ships an MCP server so coding agents can spin up mocks, peek specs, and call simulated endpoints on your behalf.

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

Try asking:

Spin up a Stripe mock locally on port 8080.
Show me which endpoints the GitHub OpenAPI spec exposes.

Read the docs

Configuration, packaging, CI integration, and the full CLI reference for the mock server.

Open the documentation

Start simulating in under 5 minutes