Mock API platform

OpenAPI mock serverPoint it at a spec and every path answers.Hosted mock serverOne stable URL, close to the team calling it.Latency and errorsMake it slow, make it fail, see what breaks.API proxyProxy the real API, mock what is missing.

PR environmentsA mock server for every pull request.History and replayEvery request kept, any of them replayed.Fake JSON APIServe your own JSON files on a real URL.All featuresEverything the mock server does.

Resilient Backends

OverviewProvider APIs, rebuilt for testing.Payment backendsAuthorisations, refunds, 3DS and decline codes.Identity: KYC and KYBDocument checks, screening and applicant flows.Self-hostedThe same providers, inside your own network.

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ArticlesGuides, comparisons and product writing.For studentsFree while you are studying.ContactAsk about a plan or a provider.

Open source

Mock server enginemockzilla GitHub Actionactions MCP servermockzilla-mcp Server templatesmockzilla-portable-template All repositories

Featured reading

Mockoon alternative: keep your mock API in sync with your OpenAPI spec Stoplight Prism alternative: an OpenAPI mock server with a URL WireMock alternative: mock an OpenAPI spec without writing stubs All articles

Mock API platform

Mock API plansFree to start, then monthly or yearly.Custom planSet your own limits and see the price.

Resilient Backends

Hosted backendsPriced per provider, on top of your plan.Self-hosted backendsPriced per provider. No plan needed.

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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

Bring a spec. Get a mock server.

It costs nothing to start. Dedicated infrastructure when you need it.

Start free Read the docs