AI Foundry Agent published to Teams - responses not delivered to user

Question

AI Foundry Agent published to Teams - responses not delivered to user

Vanessa Kukor 0

Since Azure makes it very difficult to open a support ticket I write here to hopefully get a proper answer.

We have published an AI Foundry Agent to Microsoft Teams. The agent works correctly in the Web Chat (Playground), but responses never arrive in the Teams client.

Observed behavior:

Agent receives the first message from Teams (visible in AI Foundry Tracing)
Agent generates a response (visible in Tracing)
Response is never delivered to the user in Teams
Subsequent messages are also not received by the agent
Mentioning the bot via @botname in a Teams channel also does not work

Configuration:

Messaging Endpoint API version: 2025-11-15-preview
Public Network Access: Enabled
No tools attached to the agent
Managed Identity correctly assigned

What we have verified:

Teams channel is activated on the Bot Service
App Registration permissions are correct
Public network access is enabled on the AI Account
Agent responds correctly in Web Chat / Playground
Tracing confirms agent generates the response but it never reaches Teams#
fresh creation of a botservice/agent does not solve the problem

According to an article on this issue, https://www.technetexperts.com/azure-bot-teams-reply-issue/ the root cause is thatMS Teams works asynchronously: The bot must immediately return an empty HTTP 200 OK and send the actual reply via a separate outgoing HTTP call to the Teams ServiceUrl. The Web Chat Emulator is tolerant and also accepts synchronous responses — Teams, however, completely ignores the response body. It could be that the AI Foundry Preview API (api-version=2025-11-15) does not yet correctly implement the Teams callback pattern and the agent responds synchronously instead of asynchronously. Could you verify that please?

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Answer 1

The asynchronous callback theory is not something you implement for native Foundry publishing. Foundry exposes the Activity Protocol, and the platform bridges the response to Bot Service and Teams. Empty 200 and serviceUrl logic applies when you own the bot endpoint.

Your trace proves inbound delivery and agent execution work. The break occurs after inference, most likely in Bot Service channel authentication or outbound delivery. This publishing path is currently an Early Access Preview.

Check these items:

Confirm the intended agent version is Active, then republish from Foundry.
Do not replace the generated messaging endpoint.
Verify the Bot Service App ID matches the agent application's instance identity.
Confirm the authentication mode is Channels (Azure Bot Service), then review Teams channel diagnostics.

Because a fresh bot and agent fail too, collect the trace/request IDs, UTC timestamps, region, agent application ID, Bot resource ID, Bot App ID, and instance-identity client ID, then open Azure support. Microsoft needs to inspect the preview channel bridge; RBAC or Public Network Access changes will not repair an identity mismatch.