WebSocket

Stream expressive dialogue audio over a WebSocket by sending incremental text segments per registered voice.

The connection uses Eleven v3 dialogue models only (model_id must start with eleven_v3). The default model is eleven_v3_conversational.

Session setup

• After connecting, the first JSON message must include voices (voice IDs to register for the session) and credentials if not already sent via headers or query string.
• Optional voice_settings and pronunciation_dictionary_locators are only accepted on the first message.
• For eleven_v3_conversational, only one voice ID may be registered. For eleven_v3, you may register up to 10 voices.

Streaming text

• Send inputs: an array of { "text", "voice_id", "new_turn"? }. Text for the same turn is buffered until the server has enough context (at least ~40 characters and 8 words), then partial audio chunks are emitted.
• Set new_turn to true (or switch voice_id) to finalize the current prosody segment and start a new speaker turn.

Control messages

• flush: force generation of any buffered text without closing the socket.
• close_socket: flush remaining audio, send a final message, and close the connection.
• keep_alive: reset the 20 second receive timeout (no generation).

Authentication

Use the xi-api-key or Authorization header, single_use_token query parameter, or include xi_api_key, authorization, or single_use_token in the first message body (same pattern as Text to Speech WebSocket). Anonymous sessions are rejected.

For non-streaming dialogue over HTTP, see Create dialogue and Stream dialogue.