Transcription

RealtimeKit provides two transcription modes powered by Cloudflare Workers AI:

Mode	Model	Use Case
Real-time	Deepgram Nova-3	Live captions during meeting
Post-meeting	Whisper Large v3 Turbo	Accurate offline transcription

Real-time transcription

Streams transcripts to participants as they speak using Deepgram Nova-3 via Cloudflare AI Gateway.

Enable via preset

Set transcription_enabled: true in the participant's preset:

{
  "name": "webinar_host",
  "transcription_enabled": true
}

Only participants with this flag will have their audio transcribed.

Configure

Pass ai_config.transcription when creating a meeting:

{
  "title": "Team Standup",
  "ai_config": {
    "transcription": {
      "language": "en-US",
      "keywords": ["RealtimeKit", "Cloudflare"],
      "profanity_filter": false
    }
  }
}

Option	Type	Default	Description
language	string	en-US	Language code for transcription
keywords	string[]	[]	Terms to boost recognition (names, jargon)
profanity_filter	boolean	false	Filter offensive language

Supported languages

Supports all languages available in Deepgram Nova-3

Consume transcripts

Client SDK

JavaScript

// Get all transcripts
const transcripts = meeting.ai.transcripts;

// Listen for new transcripts
meeting.ai.on("transcript", (data) => {
  if (data.isPartialTranscript) {
    // Interim result - speaker still talking
    updateLiveCaption(data.peerId, data.transcript);
  } else {
    // Final result
    appendToHistory(data);
  }
});

Transcript payload

{
  "id": "1a2b3c4d-5678-90ab-cdef-1234567890ab",
  "name": "Alice",
  "peerId": "4f5g6h7i-8j9k-0lmn-opqr-1234567890st",
  "userId": "uvwxyz-1234-5678-90ab-cdefghijklmn",
  "customParticipantId": "abc123xyz",
  "transcript": "Hello everyone",
  "isPartialTranscript": false,
  "date": "2024-08-07T10:15:30.000Z"
}

Field	Description
isPartialTranscript	true = interim (still speaking), false = final
peerId	Changes if participant rejoins
userId	Persistent participant ID
customParticipantId	Your custom ID from Add Participant API

---

Post-meeting transcription

Generates transcripts after the meeting ends using Whisper Large v3 Turbo. Transcripts from all participants are consolidated into a unified timeline and delivered via webhook or REST API.

Note

Post-meeting transcription is currently in closed beta. If you are interested in this feature, contact your account team.

Supported languages

Supports all languages in Whisper Large v3 Turbo. Uses ISO 639-1 language codes.

Output formats

Format	Use Case
CSV	Spreadsheets, data analysis
SRT	Video subtitle files
VTT	Web video captions (<track> element)
JSON	Programmatic access

CSV example

Timestamp,Participant ID,User ID,Custom Participant ID,Participant Name,Transcript
2024-08-07T10:15:30.000Z,peer-123,user-456,cust-789,Alice,Hello everyone
2024-08-07T10:15:35.000Z,peer-234,user-567,cust-890,Bob,Hi Alice

JSON example

[
  {
    "startTime": 0,
    "endTime": 2.5,
    "sentence": "Hello everyone",
    "peerData": {
      "id": "peer-123",
      "userId": "user-456",
      "displayName": "Alice",
      "cpi": "cust-789"
    }
  }
]

Fetch transcripts

Webhook

Configure meeting.transcript event in webhooks:

{
  "event": "meeting.transcript",
  "meetingId": "meeting-123",
  "sessionId": "session-456",
  "transcriptDownloadUrl": "https://...",
  "transcriptDownloadUrlExpiry": "2024-08-14T10:15:30.000Z"
}

REST API

Refer to Fetch the complete transcript for a session.

curl -X GET "https://api.cloudflare.com/client/v4/accounts/{account_id}/realtime/kit/{app_id}/sessions/{session_id}/transcript" \
  -H "Authorization: Bearer {api_token}"

Transcripts are available for 7 days after meeting ends.