Mock REST API Server

Build APIs and accelerate API development with instant mock servers

OpenAPI Mocking

Mocking your API with Stoplight is your API design’s perfect companion. Powered by Prism, the instant mock server routes incoming requests to example responses or dynamically generates examples on the fly based on your OpenAPI Specification (formerly known as Swagger).

Instant Mock Server

Supercharge any OpenAPI Specification with Stoplight Mocking. Once you have created or imported your OpenAPI Specification, you have access to an instant mock server, which automatically reloads when your specification changes. A mock API simulates the behavior of a real API allowing collaboration and feedback on your API design.


With Mocking, you can accelerate the development of new APIs. Teams can work in tandem before the API is available through virtualization. Stoplight’s mock servers can virtualize internal and external APIs within your platform with dynamic responses generated from your JSON Schema, which can be run locally or hosted with Stoplight.

Automatic Request Validation

Validates requests and responses against your OpenAPI Specification. Simulates real server behavior by automatically validating incoming request headers, query strings, and request bodies against your OpenAPI Specification.


Need a mocked response property to always be a random future date? No problem. Mocking can extend your OpenAPI Specification with scripts before or after traffic reaches your mock server. Write scripts for more complex mocking behavior, custom validations, and much more.

Want to mock your API?