Streaming voice sockets

• Streaming text-to-speech (inworld-tts-2, inworld-tts-2-flash): send sentences, or individual LLM tokens, as your model produces them and receive audio chunks back as they are synthesized, with several independent contexts on one socket.
• Streaming speech-to-text (inworld-stt-1): send microphone audio as it is captured and receive interim and final transcripts with turn boundaries.

​

Models

​

How it works

1. Mint a session credential: POST /v1/realtime/sessions with the model (and, for TTS, the voice). The gateway authenticates you, checks the org gate, reserves worst-case funds from your wallet, and returns a short-lived ephemeral_key and a wss_url on the relay’s /v1/audio/tts or /v1/audio/stt path.
2. Connect your WebSocket to wss_url with ephemeral_key and speak Inworld’s frames. The relay opens Inworld’s socket on your behalf with the platform credential; neither your AI Reserve key nor the Inworld key ever reaches your code.

​

Step 1: Mint a session

curl -X POST https://api.aireserve.com/v1/realtime/sessions \
  -H "Authorization: Bearer $AIRESERVE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "inworld-tts-2", "voice": "Ashley"}'

curl -X POST https://api.aireserve.com/v1/realtime/sessions \
  -H "Authorization: Bearer $AIRESERVE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "inworld-stt-1"}'

​

Step 2: Connect and stream

​

Text-to-speech

const ws = new WebSocket(session.wss_url, { headers: { Authorization: `Bearer ${session.ephemeral_key}` } });
ws.onopen = () => {
  ws.send(JSON.stringify({ create: { autoMode: true, autoModeStrategy: "SENTENCE_BOUNDARY", audioConfig: { audioEncoding: "MP3" } }, contextId: "turn-1" }));
  ws.send(JSON.stringify({ send_text: { text: "Hello from AI Reserve." }, contextId: "turn-1" }));
  ws.send(JSON.stringify({ close_context: {}, contextId: "turn-1" }));
};
ws.onmessage = (event) => {
  const { result } = JSON.parse(event.data);
  if (result.audioChunk) play(Buffer.from(result.audioChunk.audioContent, "base64"));
};

​

Speech-to-text

const ws = new WebSocket(session.wss_url, { headers: { Authorization: `Bearer ${session.ephemeral_key}` } });
ws.onopen = () => {
  ws.send(JSON.stringify({ transcribeConfig: { audioEncoding: "LINEAR16", sampleRateHertz: 16000, numberOfChannels: 1 }, audioProtocol: "BINARY" }));
  microphone.on("data", (pcm) => ws.send(pcm)); // raw binary frames
};
ws.onmessage = (event) => {
  const { result } = JSON.parse(event.data);
  if (result.transcript) render(result.transcript.text, result.transcript.isFinal);
};

​

Billing

• TTS is billed on the characters of every send_text the relay forwards, UTF-16 code units as Inworld counts, at the model’s rate. Inworld does not count text a cancel_context discards before synthesis; AI Reserve does, so an interruption-heavy client is charged for the last unsynthesized sentence — the conservative side. The mint reserves 3,000 characters a minute for the maximum session; the settle clamps at that reserve.
• STT is billed on connected seconds, like grok-voice. Inworld counts audio for as long as it keeps arriving, which for a live microphone is the connected session; a socket held open and silent is charged for the silence. Mute by not sending, or close the stream.
• The reserve is released and the actual charge booked by the settle sweep a few minutes after the socket closes; the row appears in your Event Log under inworld-tts-2, inworld-tts-2-flash or inworld-stt-1 with provider inworld.

​

Limits

• Sessions last at most 3540 seconds; Inworld closes a TTS socket after 10 minutes of inactivity.
• Frames are capped at 1 MiB; a client that outruns the relay’s buffers is closed with 1013.
• Concurrency is Inworld’s account tier, shared across every organization on the platform.
• Inworld’s speech-to-speech Realtime API is not served; use grok-voice or eleven-realtime-* on realtime voice sessions.