Unable to get semantic model definition via API call

[abhilash_o_p]

I'm unable to get the semantic model definition via API call. I got status_code 202 from this 

client.post(f"/v1/workspaces/{workspaceId}/items/{itemId}/getDefinition")

Then I extracted x-ms-operation-id and Retry-After from the response. Waited till the Retry-After & polled this

requests.get(f"https://api.fabric.microsoft.com/v1/operations/{operation_id}", headers=headers)

I got the below mentioned response

{'status': 'Succeeded', 'createdTimeUtc': '2025-07-23T09:49:32.9426438', 'lastUpdatedTimeUtc': '2025-07-23T09:49:34.2863596', 'percentComplete': 100, 'error': None}

I did not get the actual definition for semantic model. Please help.

Ref: Solved: Re: can't get semantic model definition via API ca... - Microsoft Fabric Community

API Ref: Items - Get Semantic Model Definition - REST API (SemanticModel) | Microsoft Learn

[v-kpoloju-msft · Accepted solution]

Hi @abhilash_o_p, 
Thank you for posting your query in Microsoft Fabric Community Forum. Also, thanks to @ibarrau, for his inputs on this thread.

Thanks for the detailed explanation you are actually just one step away from getting the semantic model definition.

You've done everything right so far: posting to the /getDefinition endpoint, handling the 202 response, waiting using Retry-After, and polling the operation status. Since the status came back as "Succeeded", the final piece is to retrieve the result of that operation.

To do that, make this follow-up call:

GET https://api.fabric.microsoft.com/v1/workspaces/{workspaceId}/operations/{operationId}/result

This is the call that actually returns the full definition JSON you're looking for.

Also, refer to the below mentioned link for better understanding:
Long Running Operations - Get Operation Result - REST API (Core) | Microsoft Learn

Hope this helps clarify things and let me know what you find after giving these steps a try happy to help you investigate this further.

Thank you for using the Microsoft Community Forum.

[ibarrau]

Hi. You know I had the same issue the other day and I think the request works like that but it's not well defined. Are you trying to get definition of a semantic model published? or is it a power bi saved as project that was sync with repo. My guess is that only that last one works with the request. You can't just get definition of a pbix published. You can try raising a ticket to support or an issue here to have microsoft reply: https://community.fabric.microsoft.com/t5/Issues/ct-p/PBI_Comm_Issues

I hope that helps,

[abhilash_o_p]

Hi @ibarrau - My requirement is to get semantic model definition (tables used, schema used, lakehouse used, measures created, etc.) & create a new semantic model by updating the definition(tables and measures remain the same, only change will be on lakehouse and schema). I'm not sure how I can do that with definition in this manner

{
  "displayName": "SemanticModel 1",
  "description": "A semantic model description.",
  "definition": {
    "parts": [
      {
        "path": "model.bim",
        "payload": "ew0KICAiY29tcGF0a..GVzIjogWyBdDQogIH0NCn0=",
        "payloadType": "InlineBase64"
      },
      {
        "path": "definition.pbism",
        "payload": "ewogICJ2ZXJzaW9uI..NldHRpbmdzIjoge30KfQ==",
        "payloadType": "InlineBase64"
      },
      {
        "path": ".platform",
        "payload": "ZG90UGxhdGZvcm1CYXNlNjRTdHJpbmc=",
        "payloadType": "InlineBase64"
      }
    ]
  }
}