Migrate from Cartesia

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Message mapping

ws.send(
  JSON.stringify({
    type: "speak",
    context_id: "turn-9",
    text: "Thanks for calling, ",
  }),
);
ws.send(
  JSON.stringify({
    type: "speak",
    context_id: "turn-9",
    text: "how can I help today?",
  }),
);
ws.send(JSON.stringify({ type: "end_of_turn", context_id: "turn-9" }));

​

Important differences

• Cartesia can multiplex multiple contexts over one socket. Bland has exactly one active turn. Sending a different context_id preempts the old one.
• Cartesia echoes the context ID on audio JSON. Bland brackets raw binary frames with utterance_start and utterance_end, so track the active context locally.
• Bland handles token buffering. You do not need to port max_buffer_delay_ms or manual flush IDs.
• Bland does not currently emit word or phoneme timestamps.
• Bland cancellation stops forwarding the active turn. Clear locally queued audio as well because delivered frames cannot be recalled.