Guide
Identify speakers in a transcript
Request Pro speaker diarization and consume optional speaker values in completed segments.
Add speaker structure without changing the job lifecycle
Diarization is an optional job flag. Creation and polling stay the same; completed segments can include numeric or string speaker identifiers when the processing result provides them.
One boolean
Set speaker_diarization to true on the transcription request.
Plan checked
The API returns pro_required when the account cannot use the feature.
Segment based
Speaker values belong to timestamped segments rather than the full text string.
Optional output
Clients should tolerate segments without a speaker value.
From request to transcript
A predictable sequence you can reuse in server applications, automations, and internal tools.
- 01
Enable the flag
Set speaker_diarization: true for a URL or uploaded-file job.
- 02
Poll normally
Use the same Location header and job endpoint.
- 03
Render segment speakers
Group or label segments using speaker when the field is present.
Make the request
Examples use the production API origin and an environment variable for the secret key.
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/media/panel-discussion.mp3",
"speaker_diarization": true
}'Requirements and boundaries
- Speaker diarization requires a Pro account.
- The flag is false by default.
- Read speaker identifiers from individual segments and format display labels in your application.
- Keep a fallback for results where a segment has no speaker value.
Frequently asked questions
What happens on a non-Pro account?+
The request returns 403 with the pro_required error code.
Is speaker a top-level response field?+
No. It can appear on individual timestamped segments.
Does enabling diarization change polling?+
No. The job remains asynchronous and uses the same status endpoint.