api-version is missing from the endpoint of a hosted MAF agent on Foundry portal

[lichtjiang]

Issue: On Foundry portal, api-version is missing from the endpoint URL of a Foundry hosted MAF agent

What I did:

I followed the instructions and steps in "Quickstart: Deploy your first hosted agent" by deploying a "Basic" Microsoft Agent Framework agent to Foundry using VS Code from creating Foundry Project, deploying a model on Foundry, populating a local python project that includes a "Basic" MAF agent, testing locally in "Agent Inspector", to deploying the agent to Foundry, via Foundry Toolkit extension.

What the agent does:
"... the agent uses FoundryChatClient from the Agent Framework and is served via ResponsesHostServer, which exposes a REST API compatible with the OpenAI Responses protocol..."

The so-called "Basic" MFA agent comes from MAF sample code here on MAF repo on GitHub:

https://github.com/microsoft-foundry/foundry-samples/tree/b29a509fe33317ff03d23e85311c0da36aa8e5eb/samples/python/hosted-agents/agent-framework/responses/01-basic

Foundry project: in "westus"
deployed model: gpt-5-nano

Dev environment & packages
I use uv to manage the project.

Dependencies:
Python@3.12.11
agent-framework-foundry@1.10.4
agent-framework-foundry-hosting@1.0.0b260730
agent-framework-core@1.13.0

VS Code extension
Foundry Toolkit@1.6.6

Agent:
Framework: MAF
Protocol type: responses

Deployment method: Code, i.e., upload code as a zip package
Package mode: Remote, i.e., Azure installs dependencies during provisioning from requirements.txt or project files.

Then I write down the endpoint of the hosted agent from its Foundry portal page in order to test the agent. And the endpoint looks like the following:
https://resource-name.services.ai.azure.com/api/projects/project-name/agents/agent-name/endpoint/protocols/openai/responses

Test the hosted agent:
I have a habit to test an agent from both code and using curl command.
It works just fine to chat with the hosted agent in code (BTW, the playground tools on both Foundry portal and in Foundry Toolkit in my VS Code are working).
But when I used the endpoint url, the curl command complains that api-version query parameter is missing.

Since no api-version is included in the endpoint can be found on Foundry portal, I came back to Foundry Toolkit in VS Code. From "Hosted agent playground", under "Deployment Details", I also saw the endpoint of the agent, which does include api-version parameter:
https://resource-name.services.ai.azure.com/api/projects/project-name/agents/agent-name/endpoint/protocols/openai/responses?api-version=2025-11-15-preview

Using this url, I was able to interact with the hosted agent using curl command.

BTW, I also created a 'native' agent using Foundry SDK. Although no api-version is seen in the endpoint url, curl command simply succeeds without asking for an api-version.

Does anyone also see this issue? Maybe this is only tied to this specific example in MAF "samples" code (MAF agent wrapped in a ResponsesHostServer, deployed on Foundry)?

[Jubin Soni (jubins)]

Nice write up, super clear repro steps.

This looks like a straight up portal bug rather than something wrong on your end. The Foundry Toolkit endpoint with ?api-version=2025-11-15-preview works because it is pulling the correct value, but whatever renders the endpoint string on the portal page just isn't appending that query param for MAF agents wrapped in ResponsesHostServer.

Good sign that your native Foundry SDK agent doesn't need it at all. That probably means the native agent path handles versioning server side, while the MAF hosted responses path expects it explicitly in the URL, and the portal is just failing to show it.

I'd file an issue against the Foundry portal team directly if you haven't already, since Toolkit and portal clearly pull from different sources for that same endpoint value. Worth including your resource region too, westus, in case it is a regional rollout gap.

Alternatively, you can also ask this on learn - Microsoft Foundry tag, but I'd try opening the bug first.

[lichtjiang]

Hey Jubin, please just go ahead and submit this as an issue.

I guess this issue would not affect most people since most of us develop agents in code, or with low-code or no-code tools, instead of wiring them up using curl commands.

One correction or a clarification to what I described as a "native" agent using Foundry SDK: it is actually a Foundry Prompt agent, which explains why no api-version is needed, as I later realized ...