When building data workflows in Alteryx, it’s common to integrate external APIs. It’s also (frustratingly) common for your API calls to fail or return unexpected results. Debugging API errors directly in Alteryx can be tricky.
This is where Postman, a powerful API client tool, comes in handy. By isolating and testing your API requests in Postman, you can quickly identify solutions before embedding them back into your Alteryx workflows.
Recently, I attempted to use the Art Institute of Chicago’s API (https://api.artic.edu/docs/#introduction) to access information about paintings stored within the museum. Their documentation shows a simple request to retrieve artworks:
I pasted this URL into a Text Input tool in Alteryx and connected it to a Download Tool. After disabling the Data Connection Manager and running the workflow, I expected to see a successful result. Instead, I got an error in the Download Tool—no data, and a cryptic status code.
The First Clue: The URL Works in a Browser
When I pasted the same URL into Chrome, it worked perfectly. JSON data came back instantly. That told me the endpoint was live and responding—so the issue had to be with how Alteryx was making the request.
Postman!
To investigate further, I created a Postman account, navigated to Workspaces, and then My Workspace.
Selecting the plus symbol will allow us to create a new request. Now we can begin troubleshooting our faulty Alteryx API call. Paste the URL into the query box and select Send, and Postman will attempt to download the data and display the results.
Sure enough, Postman returned the expected JSON. That ruled out any issues with the endpoint itself.
Inspecting Headers
In Alteryx, HTTP headers must be specified in the configuration window. Postman, however, automatically attaches headers to the request. In the headers tab, I noticed that Postman automatically included a User-Agent header (a string that identifies the client software making the request).
This missing header seems to be the reason for the 403 Forbidden error in Alteryx. Navigating back to the Download tool and adjusting the Header configuration window fixed my error.
If you’re running into unexplained API errors in Alteryx, Postman is one of the best tools for debugging! Making an account is free, so it's one of the first tools I'd use to debug an API error.