Microsoft limits async agent flow callbacks by channel
Reviewed by Helen Jones
Microsoft updated its Copilot Studio guidance for asynchronous agent-flow responses on 16 June 2026. Agent flows can now keep running beyond the previous two-minute limit, but callback responses are fully supported in Microsoft Teams and are not supported for Microsoft 365 Copilot or telephony channels.
Before this, a maker building an agent flow had a hard practical problem: long-running work could hit the normal timeout before the flow had finished. Asynchronous response support gives the flow more room to finish and return a result, which is useful for approvals, checks, document steps, or other processes that do not complete instantly. The catch is the channel. A flow can be built correctly and still disappoint users if the final callback is tested in one place but used in another. For Power Automate builders, this turns channel testing into part of the reliability checklist, not a nice-to-have after the flow works once.
Analysis
If you are adding an async response to an agent flow, test it in the exact channel people will use. Treat Microsoft Teams as the supported callback path, and do not promise the same behaviour in Microsoft 365 Copilot unless Microsoft changes the documented support.
Pulse published by Collab365 Spaces, reviewed by Helen Jones on . Cite as "Microsoft limits async agent flow callbacks by channel", Collab365 Spaces. 1 source referenced.