Prism, an Open Source HTTP Mock Server

Accelerate API development with realistic mock servers, powered by your OpenAPI documents.

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Work with your API before you write any code

Prism is an open source HTTP mock server that can mimic your API’s behavior as if you already built it. Mock HTTP servers are generated from your OpenAPI v2/v3 (formerly known as Swagger) documents.

Quickly iterate on your API

The waterfall model does not work well for building APIs. Learning at the very end what your potential consumers think about your software can be source of huge problems. With Prism you can move the feedback stage to the design phase of your API by providing a real server to use and play with.

Generate dynamic examples

Static examples in mock APIs can bias the way you write the code and test the API. Prism can generate dynamic random examples based on your API description, so the examples are always valid.

Validate input and output

Prism validates both request and response data. If you have an invalid example in the specification, Prism will let you know; if your request is not compliant with the rules of your API specification, Prism will return an error message. It will never yell to you, we promise.

Extensive logging

In case you’re wondering why Prism has responded to a request in such way, the logs show you the entire negotiation process, so you can modify the spec or your code quickly.

Do you want to mock your API in minutes?