> ## Documentation Index
> Fetch the complete documentation index at: https://circle-devdocs-test-ai-codegen-component.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# OpenAPI

> Use our OpenAPI spec to easily view APIs, create code and mock servers, and more.

*[OpenAPI Specification](https://swagger.io/specification/) (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](/circle-mint/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](https://github.com/circlefin/openapi) 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
[OpenAPI](https://github.com/circlefin/openapi) files to view them in your tool
of choice.

Here are some great viewers that we like:

1. [Swagger Editor/Viewer](https://editor.swagger.io)
2. [Swagger Hub](https://swagger.io/tools/swaggerhub/) (Requires an account)
3. Visual Studio Code:
   [OpenAPI (Swagger) Editor](https://marketplace.visualstudio.com/items?itemName=42Crunch.vscode-openapi)
   by 42Crunch or
   [Swagger Viewer](https://marketplace.visualstudio.com/items?itemName=Arjun.swagger-viewer)
   by Arjun G

## Generate Code

Use [Circle’s OpenAPI files](https://github.com/circlefin/openapi), to
auto-generate client code in your chosen programming language. Try using an
OPenAPI generator like [Swagger](https://swagger.io/).

## 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 [Prism](https://github.com/stoplightio/prism) 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:

```text theme={null}
npm install -g @stoplight/prism-cli

## OR

yarn global add @stoplight/prism-cli
```

Next, feed a specification file to Prism so that it can generate the desired
mock API server.

```text theme={null}
prism mock https://raw.githubusercontent.com/circlefin/openapi/master/openapi/json/payments.json
```

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.