_<a href="https://swagger.io/specification/" target="_blank">OpenAPI Specification</a> (OAS) OpenAPI Specification (OAS) is an API description format for REST APIs. Our OpenAPI 3.0 files allow you to view our APIs with your preferred tool, generate code, create mock servers and generate Postman collections._
If you work regularly in Postman, Circle offers a pre-packaged [Postman](🔗) collection for your convenience.
# OpenAPI Files
Circle offers you an OpenAPI file for each of the products we offer. To acquire any or all of them, visit [Circle’s OpenAPI repository](🔗) at Github.
# Alternate Viewers
Would you rather view Circle’s OpenAPI files within your own API viewer rather than the provided API References? Here are some viewers that we recommend:
Whatever the reason may be, if you prefer your own API viewer over the provided API References you can use Circle’s <a href="https://github.com/circlefin/openapi" target="_blank">OpenAPI</a> files to view them in your tool of choice.
Here are some great viewers that we like:
<a href="https://editor.swagger.io" target="_blank">Swagger Editor/Viewer</a>
<a href="https://swagger.io/tools/swaggerhub/" target="_blank">Swagger Hub</a> (Requires an account)
Visual Studio Code: <a href="https://marketplace.visualstudio.com/items?itemName=42Crunch.vscode-openapi" target="_blank">OpenAPI (Swagger) Editor</a> by 42Crunch or <a href="https://marketplace.visualstudio.com/items?itemName=Arjun.swagger-viewer" target="_blank">Swagger Viewer</a> by Arjun G
# Generate Code
Use <a href="https://github.com/circlefin/openapi" target="_blank">Circle’s OpenAPI files</a>, to auto-generate client code in your chosen programming language. Try using an OPenAPI generator like [Swagger](🔗).
# Mock Server
To reduce time in development and testing, use Circle’s OpenAPI to run a mock server of Circle’s APIs locally and in your CI environments. A mock API server allows you to emulate a real API (such as Circle) locally, in your test environments, and/or publicly. This mock server can receive requests and will respond to them with static or dynamic data that simulates what the real API would return.
## Getting started
Use the open-source tool <a href="https://github.com/stoplightio/prism" target="_blank">Prism</a> to generate a mock server from Circle’s OpenAPI specification. Prism is an open-source HTTP mock server that can mimic an API’s behavior as if it were a real server. Prism generates mock HTTP servers from your OpenAPI v2/v3 (aka Swagger) documents.
To Install Prism, run either of these two commands:
Next, feed a specification file to Prism so that it can generate the desired mock API server.
At this point you should see a trace ending with the word `
start` in green.
Now you can send requests via cURL or Postman to the destination Prism is listening on.