Multi-Context WebSocket

The Multi-Context Text-to-Speech WebSockets API allows for generating audio from text input while managing multiple independent audio generation streams (contexts) over a single WebSocket connection. This is useful for scenarios requiring concurrent or interleaved audio generations, such as dynamic conversational AI applications.

Each context, identified by a context id, maintains its own state. You can send text to specific contexts, flush them, or close them independently. A close_socket message can be used to terminate the entire connection gracefully.

For more information on best practices for how to use this API, please see the multi context websocket guide.

HandshakeTry it

GET
/v1/text-to-speech/:voice_id/multi-stream-input

Headers

xi-api-keystringOptional

Path parameters

voice_idstringRequired
The unique identifier for the voice to use in the TTS process.

Query parameters

authorizationstringOptional
Your authorization bearer token.
model_idstringOptional
The model ID to use.
language_codestringOptional

The ISO 639-1 language code (for specific models).

enable_loggingbooleanOptionalDefaults to true
Whether to enable logging of the request.
enable_ssml_parsingbooleanOptionalDefaults to false
Whether to enable SSML parsing.
output_formatenumOptional
The output audio format
inactivity_timeoutintegerOptionalDefaults to 20

Timeout for inactivity before a context is closed (seconds), can be up to 180 seconds.

sync_alignmentbooleanOptionalDefaults to false
Whether to include timing data with every audio chunk.
auto_modebooleanOptionalDefaults to false

Reduces latency by disabling chunk schedule and buffers. Recommended for full sentences/phrases.

apply_text_normalizationenumOptionalDefaults to auto

This parameter controls text normalization with three modes - ‘auto’, ‘on’, and ‘off’. When set to ‘auto’, the system will automatically decide whether to apply text normalization (e.g., spelling out numbers). With ‘on’, text normalization will always be applied, while with ‘off’, it will be skipped. Cannot be turned on for ‘eleven_turbo_v2_5’ or ‘eleven_flash_v2_5’ models. Defaults to ‘auto’.

Allowed values:
seedintegerOptional>=0<=4294967295

If specified, system will best-effort sample deterministically. Integer between 0 and 4294967295.

Send

initializeConnectionMultiobjectRequired
OR
initialiseContextobjectRequired
OR
sendTextMultiobjectRequired
OR
flushContextClientobjectRequired
OR
closeContextClientobjectRequired
OR
closeSocketClientobjectRequired
OR
keepContextAliveobjectRequired

Receive

audioOutputMultiobjectRequired
OR
finalOutputMultiobjectRequired