In this first part of the Consumed API Series, you’ll learn how to consume an external GET API in Mendix to fetch and use data inside your application. From configuring the REST call to parsing the JSON response and mapping it to entities, this guide covers everything step by step. Ideal for beginners looking to integrate third-party services.

First create the Mendix application in any version. Here, I am using 9.24.34
-> Open Mendix studio pro
-> Create new app
-> Select Blank web app

Dependencies:-

Published GET API

You can find the published API endpoint URL below. For a better understanding of how this API was created, please refer to the previous article linked above.

http://localhost:8082/rest/prsgetapi/v1/GetApi

Copy the endpoint URL and use Postman to validate the JSON response structure.

[ 
    {
      "BookName": "string", 
       "Price": 0
   }
]

Go to MX Studio MyFirstModule(YourModuleName) -> right click on it-> click on other->JSON_Structue -> give the name JSON_Book.

Open JSON_Book -> Copy upper JSON & paste it here.

Go to MyFirstModule -> right click on it-> click on other -> Import_Mapping -> give the name IMP_Book.

Open IMP_Book -> Select elements & select priviously created JSON_Book, Check all & click ok.

After clicking Ok , Click to Map automatically.

Create a microflow name it DS_GetBookData.

Go to DS_GetBookData 

1. Take a Call REST Service activity -> Under General tab pass your endpoint URL & select HTTP method(GET).

2. Go to Response tab -> Select your previously created IMP_Book import mapping & click yes Store in variable.

3. Take a retrieve activity -> Select retrieve by association & select the $Root/JsonObject_Root.

4. Lastly, return the $JsonObjectList.

Go to Home_Web page -> Take a datagrid, Under DataSource tab select DS_GetBookData microflow as a dataSource.

Now run the application & test it.

Since you’re using two different Mendix applications — one to publish the API and another to consume it — make sure the application where the API is published on localhost is running before making any API calls from the other app. If the publishing app isn’t running, the API request will fail.

I hope this article has helped you understand How to Consume GET API in Mendix.

Thanks for reading this! See you in the next blog post.