Getting started with APIs calls using Postman

Owned by Jenni Wallin
Last updated: Jun 10, 2024
3 min read

Postman is an API platform that you can use to access the APIs. It can be downloaded from Download Postman | Get Started for Free and you can select to either run it in a downloadable app or in the browser.

To access your APIs using Postman:

  1. Create an Application Access in Usage Engine as described in Configuring Application Access. Ensure to copy the Client Secret since it will only be visible when creating the Application Access.

  2. Either download the Postman app, or select to run it in a browser, and create an account and sign in.

  3. The API specification can be downloaded from the Usage Engine API page for your environment Environments. The detailed documentation of the API is available on the same endpoint.

  4. Go to the workspace and import the openapi.json specification in Postman as a Postman Collection.
    Before accessing any API, you must create a bearer token.

  5. Select which endpoint you want to start using, for example List meter types. Navigate to Authorization tab, select OAuth 2.0 as the authentication type. Configure getting the token by using {{baseUrl}}/authentication/v1/oauth/token (baseURL can be found in Environments ) and with the information provided by the Application Access. Pay attention Usage Engine CE Authorization endpoint uses "Send client credentials in body" as the Client Authentication method. We recommend using variables as in the example below.

    Screenshot 2024-06-04 at 15.12.16.png

     

  6. Add an additional Key in the token request named audience. Configure this to match the base url of the environment you are using Environments.

    Screenshot 2024-06-04 at 15.12.32.png

Note!

If the request are failing, check the URL for the audience variable to contain the ending slash to the environment.

 

  1. Once happy with you configurations, press “Get New Access Token”. This will generate a new access token.

  2. Press proceed or wait a couple of seconds. Now you will be presented with the newly created access token. Press “Use Token”.

  3. The token will now be added to the authorization header of your endpoint.

  4. Update the body and query parameters with relevant parameters and send the request.

You can now create, list, update or delete the API endpoints provided by Usage Engine.

For more information on postman variables and environments, refer to Postman variable and environment. You can save the configuration of various environment like sandbox and production using environments in Postman.

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