Test Drive opens a two-way audio session between your microphone and an agent, straight from the console. There is no phone number involved, no carrier leg and no per-minute telephony charge. Use it as the first check after wiring an agent up, before you go near a number. It removes the entire telephony path from the picture, so a failure here is unambiguously the agent — which is exactly the ambiguity that makes a first call hard to debug.
Test Drive works for agents running on the platform and for external agents you run yourself. If your worker shows as connected, you can talk to it.

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Running one

  1. Open the agent in the voice console.
  2. Start Test Drive on the agent. From the External agents list there is a Test Drive action on each agent’s row.
  3. Allow microphone access when the browser asks.
  4. Speak. You should hear the agent answer, and see the transcript fill in as the turns complete.
Stop the session from the console when you are done — see Ending a session for why the button matters.

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What it exercises, and what it does not

That split is the point. If the agent sounds right in Test Drive and wrong on a real call, the problem is in telephony. If it sounds wrong in both, the problem is in your agent.

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Audio is narrowband, on purpose

Test Drive carries 16-bit PCM at 8 kHz in both directions, the same narrowband rate a telephone call uses. It is not a higher-quality preview of your agent. This is deliberate, and it is the single most useful thing Test Drive catches early: an agent whose speech-to-text or text-to-speech is pinned to 16 kHz or 24 kHz will sound wrong here in exactly the way it will sound wrong on a call. Fix the rate when you hear it, rather than after your first customer does. The media itself rides the same transport as everything else on the platform — Media over QUIC, over WebTransport — so a browser that can reach the relay can run a Test Drive.

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Ending a session

Closing the browser tab is not enough on its own, which is why the console has an explicit stop. Ending the session properly does three things that matter to you:
  • closes your speech and model provider sessions, so nothing keeps billing for a conversation nobody is having,
  • releases an external worker from the job, so it is free for the next call,
  • tears down the media path.
If you script Test Drive in a test harness, stop the session in your teardown.

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When it does not connect

Work through these in order. They are ordered by how often each is the cause.
1

The agent is not connected

Check that the console shows your worker connected before starting a Test Drive. The platform cannot route audio to a worker that has not registered, and the failure surfaces as silence rather than an error.
2

The microphone was blocked

A denied microphone permission produces a session that opens and then sends nothing. Check the browser’s site permissions.
3

You hear nothing back

Silence in one direction, with the session otherwise healthy, is usually a sample-rate mismatch in the agent. Confirm your pipeline is running at 8 kHz.
4

The transcript stays empty

The call can be perfectly audible and the transcript still be empty. If your agent runs its own speech-to-text, it has to send each turn back to the platform — otherwise nothing reaches the transcript, the analytics timeline or the transcript webhook. See the agent recipe for the call.

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Next

Once Test Drive sounds right, assign a phone number to the agent and place a real call. Everything Test Drive skipped — signalling, routing, the carrier — enters at that point, and you will know the agent itself is already good.