Creating Fabric Eventstream via API: How to complete the KQL Data Connection configuration?

[rgsalido]

Hi everyone,

I'm trying to create a Fabric Eventstream programmatically using Python by calling the Microsoft Fabric REST API.

My current process is the following:

1. Create the Eventstream via the API.

2. Update the Eventstream definition.

3. Configure the destination as an Eventhouse with Direct Ingestion.

With this approach, I can successfully:

• Create the Eventstream

• Map the database

• Map the table in the Eventhouse

However, I'm stuck on the final configuration step.

When doing this through the Fabric UI, after publishing the topology there is an additional step called "Configure KQL Data Connection", which finalizes the connection between the Eventstream and the Eventhouse table.

I haven't been able to find how to perform this last configuration step through the API.

So my question is:

Is there a way to programmatically configure the equivalent of "Configure KQL Data Connection" for an Eventhouse destination using the Fabric API?

Any documentation, example, or guidance would be greatly appreciated.

Thanks in advance.

[rgsalido]

Hi everyone,

Just to close the loop on this thread and share the outcome in case it helps others.

We were able to fully automate the Eventstream → Eventhouse (Direct Ingestion) configuration via the REST API, but there are a few important constraints that are not obvious from the documentation.

In our case, the issue was not that the “Configure KQL Data Connection” step was unavailable via API, but rather that some hidden constraints were not being respected:

•  The default stream name must follow the pattern:       

{EventstreamName}-stream       

This name must be used consistently in the definition (streams and inputNodes).

• The connectionName must be unique per Eventstream when connecting to the same Eventhouse.
• The connectionName must be under 40 characters.

We were generating it using a full GUID, which resulted in values longer than 40 characters. When this limit is exceeded:

• No clear error is returned by the API.
• The dataConnectionId remains all zeros.
• The internal DataConnection is not materialized.
• Ingestion does not start.

After switching to a shorter, unique connectionName (well under 40 characters) and enforcing the correct stream naming pattern, the Eventstream started ingesting data correctly via API, without any manual UI step.

So yes — it is possible to fully automate this scenario, but those constraints must be respected.

Hope this helps someone else facing the same behavior.

Thanks again to the support team for the investigation and guidance.

[v-prasare]

We are following up once again regarding your query. Could you please confirm if you have raised ideas with Microsoft?
If not please raise idea and upvote it. Should you need further assistance in the future, we encourage you to reach out via the Microsoft Fabric Community Forum and create a new thread. We’ll be happy to help.

[rgsalido]

Hi,

Yes, I have already sent the idea.

Thanks!!

[v-prasare · Accepted solution]

Hi @rgsalido ,

as there is currently no official Microsoft documentation or fully supported API approach for configuring the KQL Data connection within Eventstream, we recommend submitting this as feedback or a feature request in the Microsoft Fabric community forum. This will help bring visibility to the gap and allow the product team to consider enhancing API support for this scenario. You can raise your request under the Ideas or Feedback section here: Fabric Ideas - Microsoft Fabric Community

Thanks,

Prashanth