CDN media libraries
Create transcripts for authorized recordings without downloading and re-uploading every public asset in your application server.
Direct media URL transcription API
Connect owned CDNs, object storage, podcast feeds, and media servers to speech-to-text with one source_url. The URL must return an accessible audio or video file; Fast Transcriber handles the asynchronous fetch and transcription job.
Use it from your product backend or connect a compatible AI agent over MCP.
- Bearer authentication
- Asynchronous jobs
- Structured JSON
Queue a direct audio URL
curl --include --request POST https://fast-transcriber.com/api/v1/transcriptions \
--header "Authorization: Bearer $FAST_TRANSCRIBER_API_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"source_url": "https://cdn.example.com/recordings/interview.mp3",
"speaker_diarization": false
}'202 Accepted · Location: /api/v1/transcriptions/{id}
Transcribe media where it already lives
A stable HTTP or HTTPS URL can move an audio or video asset into the same transcription workflow as supported platform links. This is useful when your application already publishes media from a CDN or produces time-limited object-storage URLs.
The source contract does not accept custom cookies or authorization headers. For protected media, download the object within your own trusted service and use the direct upload API. For signed URLs, choose an expiry that leaves enough time for queued processing to fetch the file.
With Fast Transcriber
- One asynchronous job lifecycle across supported sources
- Source resolution and media retrieval handled server-side
- One transcript response with text and timestamped segments
- A direct-upload fallback for authorized private media
Building every source yourself
- Separate URL and access handling for every source
- Queue, retry, polling, and failure-state infrastructure
- Source-specific results that need normalization
- Ongoing maintenance as external sources change
One API family
One source workflow. One predictable job model.
Use the same status lifecycle and transcript fields across supported public URLs and account-owned uploads.
What this endpoint accepts
Supported inputs
- Public HTTP or HTTPS audio file URLs
- Public HTTP or HTTPS video file URLs
- Stable CDN and object-storage media links
- Signed URLs that remain valid until the worker fetches them
Access and input boundaries
- The response must be the media file itself, not an article, player, or generic webpage.
- Use a supported file extension or an accurate audio/video Content-Type.
- source_url cannot include separate cookies, bearer tokens, or custom request headers.
- Temporary links must remain valid long enough for asynchronous retrieval.
Queue once, then follow the job
Transcription runs outside the original HTTP request. Save the returned job identity and poll its status instead of submitting duplicate work.
- 01
Send one media URL
POST source_url to /api/v1/transcriptions with a bearer API key. Create one job for each media item.
- 02
Save the job location
A valid request returns 202 Accepted. Persist the Location header and job ID instead of repeating the POST.
- 03
Poll to a final state
GET the job URL with bounded backoff until status is completed or failed, then stop polling.
Built for production transcription workflows
Podcast processing
Queue a directly downloadable episode file and store searchable text beside your existing feed metadata.
Storage automations
Generate a sufficiently long-lived signed URL when a new permitted object arrives, then track the returned transcription job.
Send a real API request
Authenticate from your backend, create the job, and store the returned Location header for status retrieval.
Queue a direct audio URL
curl --include --request POST https://fast-transcriber.com/api/v1/transcriptions \
--header "Authorization: Bearer $FAST_TRANSCRIBER_API_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"source_url": "https://cdn.example.com/recordings/interview.mp3",
"speaker_diarization": false
}'202 Accepted · Location: /api/v1/transcriptions/{id}
Implement the complete request flow
Authentication, source rules, request fields, and status handling are covered in the technical guide.
One predictable transcript response
Direct URL jobs return full transcript text plus timestamped segments in the shared JSON envelope. Store the Fast Transcriber job ID separately from the source URL so temporary links can expire safely after retrieval.
- status
- Use completed and failed as terminal states.
- text
- The complete transcript becomes available on completion.
- segments[]
- Each segment includes start, end, and text values.
- duration_seconds
- The detected duration of the processed recording.
application/json
{
"data": {
"id": "95c3fdd8-...",
"filename": "source-media.mp4",
"status": "completed",
"created_at": "2026-08-24T16:30:00.000Z",
"duration_seconds": 1842,
"text": "Completed transcript text...",
"segments": [
{ "start": 0, "end": 4.2, "text": "Welcome." }
]
}
}200 OK · completed transcript
Direct media URL API FAQ
- Can I submit any webpage URL?
- No. A direct-media URL must resolve to a supported audio or video file rather than an article, landing page, or embedded player.
- Can I send authorization headers for the source file?
- The current source_url contract does not accept source-specific headers. Retrieve protected media in your own authorized backend and use direct upload.
- Can I use a temporary signed URL?
- Yes, if it remains accessible long enough for the asynchronous worker to resolve and download the media.
- How should I identify the completed asset?
- Persist the API job ID with your own media record. Do not rely on an expiring source URL as the durable identifier.
Related endpoints
API overviewUse the same job model elsewhere
Ready to build?
Add Direct media URL transcription to your product.
Create a key, then follow the source guide to queue your first job.