Text-to-speech API

Implement the text-to-speech (TTS) API to act as a TTS provider for Live Hub, whether for a synthesis service of your own or for a vendor Live Hub does not integrate with directly. Live Hub is the client: it posts the text it wants spoken, and your service returns the audio.

Register the service as a custom integration speech provider, and enter your endpoint in the 'Text to Speech (TTS) URL' field.

Authentication

Live Hub sends the shared token from the provider's 'Authentication Key' field on every request:

Authorization: Bearer {token}

See Security and authentication.

Request

Live Hub posts a JSON body with these attributes:

Parameter	Type	Description
text	string	The text to synthesize.
type	string	Set to ssml when text contains SSML.
voice	string	Name of the voice to synthesize with.
language	string	BCP-47 language code of the text to synthesize.
format	string	Whether to return the audio with headers: wav with WAV headers, raw without. Follows the ttsPreferWave parameter.
encoding	string	The encoding to synthesize in. Only 16-bit linear PCM, LINEAR16, is supported.
sampleRateHz	number	The sample rate to synthesize at, in hertz. Only 16000 is supported.
conversationId	string	ID of the conversation the request belongs to.

{
  "language": "en-US",
  "format": "wav",
  "encoding": "LINEAR16",
  "sampleRateHz": 16000,
  "voice": "SomeVoiceName",
  "text": "Text to be played"
}

With SSML, set type and put the markup in text:

{
  "language": "en-US",
  "format": "wav",
  "encoding": "LINEAR16",
  "sampleRateHz": 16000,
  "voice": "SomeVoiceName",
  "type": "ssml",
  "text": "<speak><say-as interpret-as=\"ordinal\">1</say-as></speak>"
}

Response

Return 200 OK with the synthesized speech as the body. On failure, return an HTTP error code.

Configuration

One parameter controls the audio format Live Hub requests:

Parameter	Type	Description
ttsPreferWave	boolean	Which audio format Live Hub asks for in format. true (default) requests WAV, with a header. false requests RAW, without one. Applies to this API only.