Scribe

Zoom AI Services Scribe

Background reference for Zoom AI Services Scribe across:

• real-time audio transcription over WebSocket (wss://api.zoom.us/v2/aiservices/scribe/live)
• synchronous single-file transcription (POST /aiservices/scribe/transcribe)
• asynchronous batch jobs (/aiservices/scribe/jobs*)
• webhook-driven batch status updates
• Build-platform JWT generation and credential handling

Official docs:

• https://developers.zoom.us/docs/ai-services/
• https://developers.zoom.us/docs/ai-services/scribe/
• https://developers.zoom.us/docs/ai-services/scribe/live-mode/
• https://developers.zoom.us/docs/api/ai-services/
• https://developers.zoom.us/api-hub/ai-services/methods/endpoints.json
• Quickstart sample: https://github.com/zoom/ai-services-quickstart/

Routing Guardrail

• If the user needs live audio, uploaded media, or stored media transcribed into text, route here first.
• If the user needs transcript text summarized, route to ../summarizer/SKILL.md.
• If the user needs plain text translated, route to ../translator/SKILL.md.
• If the user needs generic live audio for voice agents, captions, or microphone transcription, use Scribe Live Mode.
• If the user needs Zoom meeting-native audio, video, screen share, chat, or transcript streams, route to ../rtms/SKILL.md.
• If the user needs Zoom REST API inventory for AI Services paths, chain ../rest-api/SKILL.md.
• If the user needs webhook signature patterns or generic HMAC receiver hardening, optionally chain ../webhooks/SKILL.md.

Quick Links

1. concepts/auth-and-processing-modes.md
2. scenarios/high-level-scenarios.md
3. examples/live-mode-node.md
4. examples/fast-mode-node.md
5. examples/batch-webhook-pipeline.md
6. references/api-reference.md
7. references/environment-variables.md
8. references/samples-validation.md
9. references/versioning-and-drift.md
10. troubleshooting/common-drift-and-breaks.md
11. RUNBOOK.md

Core Workflow

1. Get Build-platform credentials and generate an HS256 JWT.
2. Choose live mode for continuous audio, fast mode for one short file, or batch mode for stored archives / large sets.
3. Open the Live WebSocket or submit the Fast/Batch request.
4. Handle Live events, a synchronous Fast response, or Batch polling/webhooks.
5. Persist and post-process transcript JSON.

Hosted Fast-Mode Guardrail

• The formal fast-mode API limits are 100 MB and 2 hours, but hosted browser flows can still time out before the upstream response returns.
• Current deployed-sample observations:
  • ~17.2 MB MP4 completed in about 26s
  • ~38.6 MB MP4 completed in about 26-37s
  • ~59.2 MB MP4 completed in about 32-34s on the backend
  • some ~59.2 MB browser requests still surfaced as frontend 504 while backend logs later showed 200
• Treat frontend 504 plus backend 200 as a browser/edge timeout race, not an automatic transcription failure.
• For hosted UIs, prefer an async request/polling wrapper for fast mode instead of holding the browser open for the full upstream response.
• For larger or less predictable media, prefer batch mode even when the file is still within the formal fast-mode size limit.

Live Mode Guardrails

• Connect from a trusted backend with the live-asr WebSocket subprotocol and a Zoom AI Services JWT in the Authorization header.
• Configure the session with session.update, then stream binary PCM16 little-endian, 16 kHz, mono audio in approximately 100 ms frames.
• Keep control messages as JSON text. Do not Base64-encode audio or wrap binary frames in JSON.
• Browser WebSocket clients cannot set the required authorization header. Relay browser audio through a backend that adds the JWT; never expose Build credentials or JWTs in client code.
• Treat transcription.completed as the documented final segment event. Handle every error, especially error.fatal.
• On shutdown, stop audio, send session.close, continue reading final events through session.closed, then close the socket.
• Live Mode defaults: 60-minute maximum session duration and 30-second no-audio idle timeout. Concurrent limits are account-tier dependent.
• Use repeated Fast Mode microphone uploads only as a legacy fallback when a WebSocket relay is impossible; Live Mode is the preferred continuous transcription path.

Endpoint Surface

High-Level Scenarios

• On-demand clip transcription after a user uploads one recording.
• Real-time transcription for voice agents, live captions, and browser microphones through a backend relay.
• Batch transcription of stored S3 call archives.
• Webhook-driven ETL pipeline that writes transcripts to your database/search index.
• Re-transcription of Zoom-managed recordings after exporting them to your own storage.
• Offline compliance or QA workflows that need timestamps, channel separation, and speaker hints.

Chaining

• Stored Zoom recordings -> ../rest-api/SKILL.md + scribe
• Transcribe then summarize -> scribe + ../summarizer/SKILL.md
• Transcribe then translate -> scribe + ../translator/SKILL.md
• Webhook verification hardening -> ../webhooks/SKILL.md
• Generic live audio transcription -> Scribe Live Mode
• Zoom meeting-native media/transcript streams -> ../rtms/SKILL.md
• Cross-product routing -> ../general/SKILL.md

Operations

• RUNBOOK.md - 5-minute preflight and debugging checklist.