DataAgent REST API /chat endpoint returns EntityNotFound despite valid DataAgent and token

[Oleksandr_Zhuk]

Hello Fabric Community,

I’m working on integrating Microsoft Fabric DataAgents with my applications, and I’ve run into a roadblock that I’d like some guidance on.

What I’ve done so far:

• Created multiple DataAgents in a Fabric workspace (confirmed via GET /workspaces/{workspaceId}/items — they show up with "type": "DataAgent").
• Acquired an access token successfully using both service principal and user principal flows:
  • For service principal: token includes roles when .default is used.
  • For user principal: token includes scp with delegated scopes like Workspace.ReadWrite.All and Item.ReadWrite.All.
• Verified that the token audience is https://api.fabric.microsoft.com.
• Successfully listed workspaces and items using the Fabric REST API.

The issue: When I attempt to call the documented chat endpoint:

POST https://api.fabric.microsoft.com/v1/workspaces/{workspaceId}/items/{agentId}/chat

with a valid DataAgent ID and a payload like:

{
  "messages": [
    { "role": "user", "content": "Hello agent, can you summarize my data?" }
  ]
}

I consistently receive:

{
  "errorCode": "EntityNotFound",
  "message": "The requested resource could not be found"
}

What I’ve checked:

• Confirmed the agentId is correct and corresponds to a DataAgent.
• Tried multiple DataAgents in the same workspace.
• Tried both user principal (delegated scopes) and service principal (app roles).
• Verified Fabric capacity is assigned to the workspace.
• Looked in the Admin Portal tenant settings, but I don’t see a specific toggle for “Fabric data agent (preview).”

My question:

• Is the /chat REST API for DataAgents still in preview and not yet rolled out to all tenants?
• If so, how can I confirm whether my tenant is enabled for this feature, and is there a way to request early access?
• In the meantime, is the only supported way to interact with DataAgents via the Fabric UI, or should I be using Azure AI Foundry REST APIs instead?

Any guidance from the product team or others who have successfully used the /chat endpoint would be greatly appreciated.

Thanks in advance,
Alex

[v-echaithra]

Hi @Oleksandr_Zhuk ,

Fabric Data Agent Chat is only available in Microsoft Fabric AI-enabled regions. Tenants hosted in South Africa North or South Africa West cannot use the chat REST API because the Fabric AI runtime is not deployed in those geographies, and Microsoft does not support cross-geo execution for Data Agents. This is a regional limitation, not a code or permissions issue.

You can try any of these options to use Fabric Data Chat directly :

Create a new Fabric tenant in an AI-enabled region (e.g., EU or US), or

If supported by your organization, create a multi-geo secondary domain in an AI-enabled region. Once the tenant or a domain is in a supported region, the Fabric Data Agent Chat API will work as expected.
If you’d like Microsoft to review this limitation or track it as a feature request, you can submit it on the official Fabric Issues forum, where the product team monitors region support requests.
Issues - Microsoft Fabric Community

Hope this helps.
Thank you.

[v-echaithra]

Hi @Oleksandr_Zhuk ,

May I ask if you have resolved this issue? Please let us know if you have any further issues, we are happy to help.

Thank you.

[Oleksandr_Zhuk]

Actually, my real question is - How to use Fabric Data Chat directly without calling Azure AI Foundry? Because I implemented it via Azure AI Foundry, but it's required for me to use it with Fabric API (C# code). 

[Oleksandr_Zhuk]

It's required to use C# approach

[Oleksandr_Zhuk]

I’m trying to confirm whether the Fabric Data Agent API (and related Copilot-backed features) are currently supported for tenants in the South Africa North region.

Specifically, I’d like to understand the following:

1. Is South Africa West considered a Power BI-only region, and therefore ineligible for direct Fabric API or Copilot/Agent use?

2. If so, would hosting Fabric capacity in another supported region (e.g., Europe, UAE, or North Europe) and enabling Cross-geo AI processing allow API calls to work?

3. Are there any known limitations or restrictions for enabling Cross-geo processing/storing from a South Africa West tenant?

4. Is there an official list or documentation that specifies which regions currently support Fabric Data Agent APIs?
   
   And so, can I use this endpoint to receive data from my Fabric Data Agent right?
   
   

   POST https://api.fabric.microsoft.com/v1/workspaces/{workspaceId}/items/{agentId}/chat

[v-echaithra]

Hi @Oleksandr_Zhuk ,

We’d like to follow up regarding the recent concern. Kindly confirm whether the issue has been resolved, or if further assistance is still required. We are available to support you and are committed to helping you reach a resolution.

Best Regards,
Chaithra E.

[SaiTejaTalasila]

Hi @Oleksandr_Zhuk ,

Try python SDK-

 If you're exploring programmatic access to DataAgents, check out the Fabric Data Agent SDK. It’s designed for use in Fabric notebooks and supports agent creation, configuration, and interaction. 

If it is not working, you can open a ticket with Microsoft support.

Thanks,

Sai Teja 

[v-echaithra]

Hi @Oleksandr_Zhuk ,

Check if the chat endpoint is fully available in your region/tenant. To check if the Chat Endpoint is fully available in your region or tenant, it's important to confirm whether the feature is rolled out to your specific environment.
As you mentioned, there’s no visible toggle for "Fabric data agent (preview)" in the Admin Portal, which suggests the feature may not be available yet in your tenant. In this case, you would need to request early access or join a preview program if it's not enabled.

Additionally, ensure the DataAgent is properly initialized and functioning. Sometimes, an agent may appear in the workspace but isn't fully ready for interaction via the API. You might want to verify its status to confirm it's fully operational.

Finally, double-check the permissions for both the user principal and service principal. Even though you’ve already assigned Workspace.ReadWrite.All and Item.ReadWrite.All, confirming that the token is granting the appropriate scopes is crucial. You could also try adding User.Read to the token to ensure there’s no missing permission.

Hope this helps.
Chaithra E.