One request turns text into audio with the voices of ElevenLabs, HeyGen and Google Cloud.
For paid plans and credit packs, from your own server
curl -X POST https://api.sonnalabs.app/api/v1/tts/synthesize \
-H "Authorization: Bearer $SONNA_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: $(uuidgen)" \
-d '{
"text": "Welcome to SonnaLabs, where your words turn into lifelike speech in seconds.",
"voice": "06f2ddd4-70ab-4e0f-a92f-8504bef52533",
"ttsModel": "eleven-v4-turbo"
}'{
"url": "https://…/speech.mp3",
"remainingCredits": 108420
}Open the console, name a key and copy it once. It starts with sona_sk_.
sona_sk_1a2b3c…POST the text, a voice and a model. The call waits for the audio and returns it.
POST /api/v1/tts/synthesizeThe response holds the address of the finished audio and your remaining credits.
{ "url": "…", "remainingCredits": … }Every request goes to the same host and carries your key.
https://api.sonnalabs.app/api/v1/tts/synthesizeSpeech from one voice./api/v1/tts/synthesize-dialogueA conversation between several voices./api/v1/tts/enhanceAdds expressive audio tags to your text./api/v1/tts/voicesThe voices you can use, with their ids./api/v1/tts/modelsThe models and what each one needs./api/v1/user/creditsYour credit balance and plan.Put the key in an Authorization header or in X-API-Key; both work on every endpoint. Keep it on your server, out of pages and apps that others can open, and never in a URL.
Authorization: Bearer sona_sk_…
# or
X-API-Key: sona_sk_…Pass one of these ids. The voice must belong to the same provider as the model.
eleven-v4eleven-v4-turboeleven-v3eleven-multilingual-v2eleven-flash-v2-5heygen-voiceheygen-voice-turbogoogle-neural2google-wavenet
Credits are taken before the audio is made and returned automatically when a request fails.
Send an Idempotency-Key and a retry after a dropped connection is answered from the first attempt, never charged twice.
Rate-limited endpoints answer with X-RateLimit-Limit, -Remaining and -Reset, and a Retry-After on 429.
Errors come back as JSON with a code you can branch on.
INVALID_REQUESTTEXT_TOO_LONGINSUFFICIENT_CREDITSPAID_ACCESS_REQUIREDDUPLICATE_REQUEST_RETRYRATE_LIMIT_EXCEEDEDPROVIDER_BUSY
Create and revoke keys, up to 10 active at a time. A key is shown once.
See the credits you spend, day by day, and where they go.
Check the latest requests and whether they succeeded, without logging on your side.
Browse the catalog with the ids you put in a request.
Create a key in the console and make your first request in minutes.