What I wanted
An AI voice agent answers the call and works out what the caller needs, then hands over to a person in Teams. That person should see what the AI already learned without asking the caller to repeat it. The call path has no Dynamics 365 Contact Center and no third-party contact centre product: just Azure Communication Services on Teams Phone.
Findings
- How you hand the call over matters. One hand-off method accepted the context and returned success every time, yet the agent never saw it. A different method delivered it first time.
- A success response doesn’t prove delivery. The breakthrough came from looking at what the Teams client actually received, not at what the API said.
- Call queues work too. The context survives the queue and reaches whoever answers.
- The context panel is desktop and web only. Teams mobile doesn’t show it, so don’t promise it to mobile-first teams.
Wins
- Low per-call cost across 232 inbound calls. On this path the telephony side adds very little; most of the cost is speech and the AI platform.
- It runs on the supported Teams Phone path, not on the ACS phone-number features Microsoft is retiring in 2028.
- The pieces are now one reusable platform core, not a set of one-off builds.
Takeaway
When a platform accepts your data and nothing shows up, check what the other end received before changing the data again.