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Product summary

Imposter is a mock server for REST APIs, OpenAPI (and Swagger) specifications, SOAP web services (and WSDL files), Salesforce and HBase APIs.

  • Run standalone mock servers in Docker, Kubernetes, AWS Lambda or on the JVM.
  • Embed mocks within your tests (JVM or Node.js) to remove external dependencies.
  • Script dynamic responses using JavaScript, Groovy or Java.
  • Capture data from requests, then store it or return a templated response.
  • Proxy an existing endpoint to replay its responses as a mock.

Getting started

To begin, check out our Getting started guide. See the User documentation for more.


  • run standalone mocks in place of real systems
  • turn an OpenAPI/Swagger file or WSDL file into a mock API for dev or QA (use it before the real API is built)
  • decouple your integration tests from the cloud/back-end systems and take control of your dependencies
  • validate your API requests against an OpenAPI specification
  • capture data to retrieve later, or use in templates to for conditional responses
  • proxy an existing endpoint to replay its responses as a mock

Send dynamic responses:

  • Provide mock responses using static files or customise behaviour based on characteristics of the request.
  • Power users can control mock responses with JavaScript or Java/Groovy script engines.
  • Advanced users can write their own plugins in a JVM language of their choice.

Mock types

Imposter provides specialised mocks for the following scenarios:

  • OpenAPI - Support for OpenAPI (and Swagger) API specifications.
  • REST - Mocks RESTful or plain HTTP APIs.
  • SOAP - Support for SOAP web services (and WSDL files).
  • HBase - Basic HBase mock implementation.
  • SFDC (Salesforce) - Basic Salesforce mock implementation.
  • WireMock - Support for WireMock mappings files.