Forum Discussion
Issue trying to get Semantic Model via api
What you are describing in the behavior of long running operations in Microsoft Fabric APIs.
For APIs which return a result, like the "getDefinition", once the "Get Operation State" returns 200 with status:Succeeded, it will contain another URL for fetching the result. It should look like this in your case:
https://wabi-us-east2-b-primary-redirect.analysis.windows.net/v1/operations/{guid}/resultSee this documentation for more details: Long running operations - Microsoft Fabric REST APIs | Microsoft Learn
No idea if you found resolution, but It sounds like I have been exploring where you are. I am by no means fluent in API, but I can give my experience/likely incorrect understanding. Once you send the POST to actual start the process of getting the definition it makes a result file out on the server(eventually goes away btw). The output you get back from that should have a line with this in it
"x-ms-operation-id": "{some form of a GUID}"
Then you have to send a
GET https://api.fabric.microsoft.com/v1/operations/{GUID of result from previous}/result
The output of this last command sends you the information inform of line with payload that is encoded in base64. But nonetheless it eventually allows you to see SQL embedded in the model and other attributes.
What I have yet to figure out is how to actually edit that SQL, re encode base64, then update that model defintion. At a MediaTypeError so far, and swapped away from TMDL(default of get definition) to TMSL(seems to be what update wants) format.
Again I am not by any means fluent in API, just wanted to give my experiences with getting to a point to read/see the definition if it helps anyone.