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grist.tools Audio Convert
x402
grist.tools Audio Convert is a paid API for AI agents from grist.tools, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-02).
Converts an audio or video file (by URL) to a target audio format such as MP3, WAV, FLAC, AAC, or Opus using ffmpeg, for $0.003 per call.
Price / call$0.003
Success—
StatusUnknown
How this service works
One endpoint does one thing, always the same way, for a fraction of a cent. Payment is verified before the handler runs and settled only after it succeeds, so a rejected or failed call is never a charged call.
Output
Returns the converted audio file in the requested format (mp3, wav, flac, aac, or opus). The output is the raw audio stream or container corresponding to the chosen format, processed from the first audio stream of the source file.
Example use cases
Podcast episode format conversion
“I have a podcast episode hosted at https://media.mypodcast.com/ep42.wav — can you convert it to mp3 at 128 kbps so it's smaller for distribution?”
Extract audio from video for transcription
“Grab the audio from this video at https://cdn.example.com/interview.mp4 and convert it to a 16000 Hz wav file so I can send it to a speech-to-text service.”
Convert music to Opus for web streaming
“Convert this flac file at https://storage.example.com/track.flac to opus at 96 kbps so I can stream it efficiently on my web app.”
Technical details
Endpoint
POSThttps://grist.tools/v1/audio-convert?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a simple, pay-per-call audio format conversion without managing ffmpeg infrastructure. It is ideal for agents that occasionally need to transcode audio files on demand (e.g. before sending to a speech-to-text API, normalizing podcast audio, or preparing files for web streaming). At $0.003/call it is cost-effective for low-to-medium volume workflows. Prefer it over self-hosted ffmpeg when you want zero infrastructure overhead and atomic per-call billing.
Side effects
- Source URL is unreachable or returns a non-200 response — conversion fails with an error
- Source file format is not a recognized container (MP4/MOV, MKV/WebM, AVI, Ogg, WAV, FLAC, AIFF, MP3) — unsupported format error
- Audio duration exceeds 3600 seconds — rejected before processing
- Unsupported bitrate value outside 8–512 kbps range (or >192 for AAC) — validation error
- Invalid sample_rate value not in the allowed set — validation error
- Payment rejected or insufficient — call never executes
- Network timeout fetching the source URL — conversion fails
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| to | string | Output format: wav (16-bit PCM), mp3 (LAME), flac, aac (ADTS stream) or opus (in an Ogg container); defaults to mp3. |
| urlrequired | string | Absolute http(s) URL of the source file, up to 2048 characters; the first audio stream of a recognised container (MP4/MOV, Matroska/WebM, AVI, Ogg, WAV, FLAC, AIFF or MP3) is converted, and it must last at most 3600 seconds. |
| sample_rate | integer | Output sample rate in Hz, one of 8000, 11025, 16000, 22050, 32000, 44100 or 48000; when omitted ffmpeg chooses the rate, normally the source rate. |
| bitrate_kbps | integer | Target bit rate in kbps, lossy formats only (mp3, aac, opus): 8 to 512, and at most 192 for aac. |
Tags
x402
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