Voice API

Our voice model, outside the platform

Call the same text-to-speech and speech recognition engine that powers Proto’s AI agents – directly from your own application, on prepaid credits. No plan required – available on Free accounts.

Get API keys Read the reference →

Language

Search for language

Gender

Female

Format

mp3

Speed1

curl -X POST "https://v3-api.proto.cx/api/platform/v1/voice/{teamspace_id}/tts" \
  -H "Authorization: Bearer ••••••••••••3f9a" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "",
    "lang": "tl",
    "response_format": "mp3",
    "speed": 1.00,
    "gender": "female"
  }'

The API

Two endpoints

Both authenticate with a bearer token scoped to your teamspace, and both draw on the same voice-credit balance.

Read the reference →

POST /tts

Text-to-speech

Synthesis built from native recordings, not an English voice bent towards a local accent.

Native speaker recordings, not converted English models
Voice, gender and accent selectable per language, speed 0.25–4.0
Up to 5,000 characters a request, returned base64-encoded as MP3 or WAV

POST /asr

Speech recognition

Transcription built for regional accents and sentences that move between a local language and English mid-clause.

Tuned for regional accents and mixed-language phrasing
Transcribes up to 15MB of MP3 or WAV audio a request
Transcript returned with an optional English translation

Try it

Call both endpoints from the browser

Type a phrase to hear it spoken, or send a recording to be transcribed – the same requests your own code would make.

Language

Speed

Pricing

Volume pricing, on your balance

The rate steps down as usage grows — size your own volume below rather than reading one headline number that only holds for the first 10,000 credits.

credits a month

$0a month, at $0.000 a credit blended

Buy voice credits

First 10,000$0.050/credit0$0

10,000 – 100,000$0.040/credit0$0

100,000 – 1,000,000$0.025/credit0$0

1,000,000 – 5,000,000$0.010/credit0$0

Its own balance

Voice requests draw on prepaid voice credits, not on your platform interaction volume. The two balances are billed and tracked separately.

1 credit a request

Every successful text-to-speech or speech-recognition call costs 1 credit, at any tier. A failed request is not charged.

50 credits free

Every new workspace starts with 50 voice credits, no plan or purchase required to try it.

No plan required

Voice credits can be bought on any plan, from Free upward — there is no tier to reach first.

This covers Voice API credits only – the Proto platform itself (AI agents, users and teams, channels, languages, teamspaces, analytics) is billed separately and isn’t included in the numbers above.

What comes with every credit

Auto top-up, low-balance alerts, usage you can break down by request, and every language included from day one – not extras, just how the balance works.

Explore features & pricing

Auto top-up

Set a threshold and a further balance is applied automatically, so a live conversation never stops mid-call for want of credit.

Auto top-up enabled

Top up when balance falls below100credits

Low-credit alerts

Get notified by email and in-platform before your balance runs out, well before a request starts failing.

Low voice credit balance

2m ago

42 credits left – top up to keep text-to-speech and speech recognition answering.

Usage you can attribute

A dedicated usage tab breaks consumption down by request type, teamspace and language.