Paxa Labs

Paxa Labs generates speech in Thai, English and Mandarin Chinese, including sentences that mix them. The same Paxa API key also serves speech recognition. Paxa tuning is passed in synthesizer.options.

{
  "verb": "say",
  "text": "[warm, unhurried] สวัสดีครับ your order ships today ครับ",
  "synthesizer": {
    "vendor": "paxa",
    "language": "th-TH",
    "voice": "khanomkrok",
    "options": {
      "speed": 1.0
    }
  }
}

You can also set these in the portal under Extra Options on the speech credential, in which case they apply to every request that uses that credential. Settings supplied on the verb take precedence.

Credential

Create an API key on the API keys page of the Paxa dashboard. Keys start with pxa_, and jambonz sends the key as a Bearer token. Add it as a Paxa Labs speech credential in the portal or API; one credential is used for both text-to-speech and speech-to-text.

Models

Pick the model on the speech credential.

Voices and languages

A voice is a lowercase id such as khanomkrok or nomyen. Every paxa-tts-flash-v2 voice speaks Thai, English and Mandarin Chinese, and a single sentence can switch between them without any markup. Paxa’s voice list covers both models.

Designed voices you have saved in your Paxa account have ids that start with voice_. They work with paxa-tts-flash-v2 only, and only with an API key from the account that saved them.

synthesizer.language does not pick the voice’s language, since words are spoken in the language of their script. It sets how codes, digits and symbols are read: th-* is sent as th, en-* as en, and zh-* or cmn-* as zh. Any other language is not sent, and Paxa follows the language most of the text is written in. Set options.language to choose explicitly; it takes precedence over synthesizer.language.

Direction tags

On paxa-tts-flash-v2, write tags into the text to direct the delivery: a direction in square brackets such as [whispering] or [calm, measured] changes how the following words are spoken, sounds such as [laughs] play where they are written, [um] and [hmm] are spoken as hesitations, and <emph>…</emph> and <whisper>…</whisper> mark a span. jambonz passes tags to Paxa unchanged. Paxa rejects some tags, such as accents, other voices or a bracket without letters, with a tag_invalid error; see Paxa’s direction tags for the full rules. On paxa-tts-flash-v1 only the experimental voices read tags.

Options

Every option is optional. An option you don’t set is not sent, so Paxa’s own default applies.

Endpoint override

To point at a non-default endpoint, such as a proxy, set api_uri in the credential’s Extra Options; it applies to both TTS and STT. Leave it out to use api.paxalabs.com.

Streaming

Paxa supports TTS streaming, so it can be driven token by token from an LLM using tts:tokens, for example from the agent verb. jambonz streams text to Paxa over a live connection, and on barge-in sends Paxa’s cancel instead of reconnecting.

Paxa returns word-level timestamps, so alignment events are available when alignment is enabled. Paxa bills speech with timestamps at a higher rate than plain speech; see Paxa’s pricing.