STT

Speech-to-Text

Two tiers of audio transcription, paywalled via x402. Provide a URL to an audio file, get back the transcript with language detection and duration. The operator's OPENAI_API_KEY handles upstream auth.

Tiers

Endpoint	Price	Model	Max duration
POST /api/transcribe	$0.03	gpt-4o-mini-transcribe	5 min
POST /api/transcribe-pro	$0.10	gpt-4o-transcribe	10 min

Both tiers are wallet-only — every call burns real upstream transcription credit. See Security Model.

Supported audio formats

mp3, mp4, mpeg, mpga, m4a, wav, ogg, flac, webm (max 25 MB)

Request / Response

// Request
{ "url": "https://example.com/audio.mp3", "language": "en" }

// Response
{ "model": "gpt-4o-mini-transcribe", "provider": "openai",
  "text": "Hello, this is a sample transcription.",
  "language": "en", "duration": 3.5 }

Only url is required. language (ISO-639-1 code) is optional but improves accuracy.

See also

• Text-to-Speech — the reverse: text to audio
• LLM Proxy Gateway — text inference
• Paying with x402 — the USDC payment flow