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  • Voices
    • POSTCreate voice
    • GETList voices
    • DELDelete voice
  • Text-to-Speech (TTS)
    • WSSStream Input
    • STREAMText-to-Speech (Streamed JSON)
    • POSTText-to-Speech (Streamed File)
    • POSTText-to-Speech (Json)
    • POSTText-to-Speech (File)
    • POSTVoice Conversion (Streamed File)
    • STREAMVoice Conversion (Streamed JSON)
  • Speech-to-speech (EVI)
    • WSSChat
  • Expression Measurement API
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Text-to-Speech (TTS)

Stream Input

WSS
wss://api.hume.ai/v0/tts/stream/input
Handshake
URLwss://api.hume.ai/v0/tts/stream/input
MethodGET
Status101 Switching Protocols
Messages
Generate emotionally expressive speech.
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Text-to-Speech (Streamed JSON)

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Handshake

WSS
wss://api.hume.ai/v0/tts/stream/input

Query parameters

access_tokenstringOptionalDefaults to
Access token used for authenticating the client. If not provided, an `api_key` must be provided to authenticate. The access token is generated using both an API key and a Secret key, which provides an additional layer of security compared to using just an API key. For more details, refer to the [Authentication Strategies Guide](/docs/introduction/api-key#authentication-strategies).
context_generation_idstringOptional
The ID of a prior TTS generation to use as context for generating consistent speech style and prosody across multiple requests. Including context may increase audio generation times.
format_typeenumOptional
The format to be used for audio generation.
include_timestamp_typeslist of enumsOptional
The set of timestamp types to include in the response. Only supported for Octave 2 requests.
Allowed values:
instant_modebooleanOptionalDefaults to true

Enables ultra-low latency streaming, significantly reducing the time until the first audio chunk is received. Recommended for real-time applications requiring immediate audio playback. For further details, see our documentation on instant mode.

no_binarybooleanOptionalDefaults to false
If enabled, no binary websocket messages will be sent to the client.
strip_headersbooleanOptionalDefaults to false

If enabled, the audio for all the chunks of a generation, once concatenated together, will constitute a single audio file. Otherwise, if disabled, each chunk’s audio will be its own audio file, each with its own headers (if applicable).

temperaturedoubleOptional
Sampling temperature for the speech generation model. Higher values increase variation; lower values increase consistency. **This is an experimental parameter.** It is recommended to use the default values for most use cases. Defaults when omitted: - Octave 1 voice creation (no voice specified): `0.9` - Octave 1 text-to-speech: `0.8` - Octave 2 text-to-speech: `0.75`
versionenumOptional
The version of the Octave Model to use. 1 for the legacy model, 2 for the new model.
api_keystringOptionalDefaults to

API key used for authenticating the client. If not provided, an access_token must be provided to authenticate.

For more details, refer to the Authentication Strategies Guide.

Send

InputMessageobjectRequired

Receive

TtsOutputobjectRequired

Access token used for authenticating the client. If not provided, an api_key must be provided to authenticate.

The access token is generated using both an API key and a Secret key, which provides an additional layer of security compared to using just an API key.

For more details, refer to the Authentication Strategies Guide.

Sampling temperature for the speech generation model. Higher values increase variation; lower values increase consistency.

This is an experimental parameter. It is recommended to use the default values for most use cases.

Defaults when omitted:

  • Octave 1 voice creation (no voice specified): 0.9
  • Octave 1 text-to-speech: 0.8
  • Octave 2 text-to-speech: 0.75