Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Soniox Text-to-Speech

Deepgram Text-to-Speech (Aura-2, Flux TTS)

OpenAPI 3.1 and AsyncAPI files, llms.txt and Markdown pages. Requests can be kept for training unless each one sets mip_opt_out=true.

Soniox Text-to-Speech

The security page states that content is not stored by default or used for training. Audio output is capped at two minutes per request or stream.

Deepgram Text-to-Speech (Aura-2, Flux TTS)

1. Set mip_opt_out=true on every request if the text mustn't be kept for training.
2. Split Aura-2 REST text under 2,000 characters or expect a 413.
3. Pass model on /v2/speak, where it's required.
4. Strip SSML before sending, since it's removed with an INPUT_MARKUP_STRIPPED warning.
5. Back off exponentially on 429 and keep traffic in one project.

Soniox Text-to-Speech

1. Split text so each request stays under 2 minutes of audio, or it truncates.
2. Branch on error_type, not the message, and back off on limit_exceeded.
3. Use a temporary API key for browser clients.
4. Use bracketed audio tags such as [whispering] instead of SSML.
5. Pick the regional host (EU, Japan, India) that matches your data residency.