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Speech-to-Text Transcription (Whisper Large v3 Turbo)
x402
Speech-to-Text Transcription (Whisper Large v3 Turbo) is a paid API for AI agents from flat-rate-llm.kikoribera03.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).
Transcribes audio files to text using Whisper large v3 turbo, returning the transcript, detected language, duration, and timed segments with optional word-level timestamps.
Price / call$0.01
Success—
StatusUnknown
How this service works
Transcribes an audio file with Whisper large v3 turbo: pass an https URL (mp3, wav, flac, m4a, ogg, up to 10 MB) or base64 audio in a POST. Returns the text, the detected language with its probability, the duration, and timed segments; add words=true for word-level timestamps. Around 100 languages. You are only charged if the transcript is delivered. No API key, no account.
Output
Returns a JSON object containing the full transcript text, the detected language code (e.g. 'en', 'es') with a confidence probability, the total audio duration in seconds, an array of timed segments each with start/end times and segment text, and optionally word-level timestamps for each word when words=true is requested.
Example use cases
Podcast episode auto-transcription
“Transcribe this podcast episode for me — the MP3 is at https://example.com/episode42.mp3 — and give me the full text plus the detected language so I can publish it as show notes.”
Multilingual voicemail to text
“I have a voicemail recording at https://example.com/voicemail.wav that might be in Spanish or Portuguese — can you transcribe it and tell me which language it is and how confident you are?”
Meeting recording with timed captions
“Turn this meeting recording into a transcript with word-level timestamps — the file is at https://example.com/standup.m4a — I need the segments so I can build a searchable caption file.”
Technical details
Endpoint
POSThttps://flat-rate-llm.kikoribera03.workers.dev/v1/ai/transcribeWhen to prefer
Choose this endpoint when you need fast, affordable audio transcription without account setup or API keys, supporting ~100 languages with timed segment output and optional word-level timestamps. Ideal for agents that need to process one audio file at a time via URL or base64, at $0.01 per call with no subscription overhead. Prefer over self-hosted Whisper when you want zero infrastructure, or over larger providers when cost and simplicity matter.
Side effects
- Audio file URL not accessible or returns non-200 status — transcription fails with an error
- File exceeds 10 MB limit — request rejected
- Unsupported audio format provided — returns format error
- Network timeout fetching remote audio URL — transcription fails
- Very low audio quality or silence — returns empty or inaccurate transcript
- Language detection confidence may be low for very short or noisy clips
Tags
x402
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