Participant Model

Every Call has two parties and one agent. On outbound calls, inbound audio for the remote party is typically on the callee track - selecting the wrong stream is a common integration error.

Parties vs agent

• Parties: caller (who placed the call) and callee (who was called).
• One of them is always the subscriber (your connector’s line); the other is the external participant.
• The agent is your code. It listens via caller / callee .audio_stream() and speaks with send_audio(). It is not a third party identity.

caller / callee are membership, not liveness - who the call is between, not who has picked up yet.

Inbound seeding

Outbound

After make_call + dial, the dialed party is typically on the callee track - stream call.callee.audio_stream().

The one rule: is the agent in the audio path?

Ambient modes (after connect())

Subscriber on inbound = your staff line (callee). On outbound = your line (caller).

Per-party audio

async for chunk in call.caller.audio_stream():
    ...  # only the caller
async for chunk in call.callee.audio_stream():
    ...  # only the callee

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