Use the media file itself
The URL must directly serve the recording from a supported S3 or R2 object-storage host. Website pages, video-sharing watch pages, private network addresses and redirected links are not supported.
Keep the link available during upload
A signed file URL can work if it lasts through ingestion. The service retrieves and validates the recording before quoting. Once the quote is returned, the accepted file is already stored for this job.
The quote belongs to those bytes
The quote is for the file retrieved at intake. Changing what the original URL serves does not replace a quoted recording. Submit a new file only when you mean to create a new purchase.
POST /v1/transcriptions
Content-Type: application/json
{"media_url":"https://your-bucket.s3.amazonaws.com/recording.mp3"}