Foundry New endpoint protocol does not support workflow agents

Hi BU XINZHE ,

Thanks for raising this. This issue with the new Foundry endpoint usually comes up when there is a mismatch between how the request is structured and what the new protocol expects.

what is happening

The new Foundry endpoint follows the updated OpenAI compatible API format. Some older parameters or patterns that worked before may not be supported in the new protocol.

So when you see errors like “not supported” or similar, it usually means:

• The request is using an older format
• Or a parameter is no longer valid in the new API

What you should check

1. Verify endpoint format

Make sure you are using the correct endpoint format for Foundry projects.

It should look like this:

• project based endpoint
• uses openai v1 path

If you are still using older Azure OpenAI style endpoints, that can cause issues.

2. Check request structure

The new API expects requests in standard OpenAI format.

Make sure:

• messages array is used instead of older prompt format
• roles like system, user are defined correctly
• request body matches the expected schema

Old fields or custom fields may not be recognized.

3. Validate parameters

Some parameters have changed or are no longer supported.

For example:

• older token parameters may be replaced with newer ones
• certain options may not be supported in all models

If you are reusing older code, this is a common cause.

4. Check model compatibility

Not all models support all features.

Make sure:

• the model you are using supports the features you are passing
• advanced options are not used with unsupported models

5. Test with a minimal request

Try sending a very basic request first:

• simple message only
• no optional parameters

If that works, then gradually add parameters to see what is causing the issue.

6. Compare with working sample

Use a basic working example from documentation and compare with your request.

This helps identify:

• missing fields
• incorrect structure
• unsupported parameters

This is not usually a runtime issue in your workflow. It is mostly due to differences between old and new API formats.

The new endpoint is stricter and expects requests to follow the updated schema.

Reference: You can review the official documentation here for correct request structure: https://learn.microsoft.com/azure/foundry

In short:

• The new endpoint uses a different protocol
• Older request formats may not work
• Validate endpoint, request body, and parameters
• Start with a minimal request and build up

I hope this helps. Do let me know if you have any further queries.

Thankyou!

Thanks for the AI summary. To confirm: this is being treated as a

service-side regression on the legacy workflow endpoints, since the

documented transition guarantees backward compatibility.

Could a moderator escalate to the Product Group? We do not have an

Azure support plan, and this is blocking workflow-based agents

across multiple subscriptions and regions in our organization.

Additional Request IDs and conversation_ids available on request.

Reproduction:

• Multiple subscriptions, Japan East + another region
• "Test in Playground" via workflow → fails instantly with "Error creating item on conversation"
• New endpoint route (/agents/.../endpoint/...) → returns "Agent kind 'workflow' is not supported"

We would appreciate confirmation of whether:

(a) Engineering is aware of the regression

(b) Workflow-kind support on the new endpoint is on the roadmap