What’s In This Guide
Below you’ll find a table that maps between the two APIs: For instance, old base URL -> new base URL, old Accept header -> new Accept header, etc. This mapping only includes things that exist in both APIs but differ slightly. So for instance, both APIs have a list accounts endpoint, but the route for each is the same (GET /users/{user_guid}/accounts); hence, this isn’t included in the table. On the other hand, both APIs have a Connect Widget endpoint, but the routes are different (POST /users/{user_guid}/connect_widget_url in Atrium and POST /users/{user_guid}/widget_urls in Platform); hence, this is included in the table.
If you can’t find what you’re looking for in the table, it’s safe to assume that the feature or function is identical in both APIs, or it simply doesn’t exist on one of them.
Let’s get started by explaining the biggest differences in their own sections. After that, you’ll find the mapping table.
Important Differences
Authentication
One important change in the Platform API is how authentication works. In Atrium, you used theMX-API-Key and MX-Client-ID in separate headers. In Platform, you send the URL-safe Base64 encoding of both these values combined in a single Authorization header.
In other words, CLIENT-1234:API-KEY-4567 encodes to Q0xJRU5ULTEyMzQ6QVBJLUtFWS00NTY3, so the header and value would be Authorization: Basic Q0xJRU5ULTEyMzQ6QVBJLUtFWS00NTY3.
Here are a couple of example requests to make it more clear.
Fields and Field Naming
While Atrium and Platform don’t return the same set of fields for every resource (e.g., there are differentmember fields in Atrium than in Platform), fields that appear in both will have the same name and definition.
There is one important exception to this: The identifier field is called id in Platform. The definition for both is identical and the values you’ve assigned to it for various resources haven’t changed; we simply shortened the key.

