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Speaker identification, 100+ languages, word-level timestamps. Perfect for depositions, hearings, and interviews.
Endpoint
POST /voice/transcription
Upload your audio to a vault, then transcribe with automatic result storage. The transcript is saved back to your vault when complete. 
import Casedev from 'casedev';

const client = new Casedev({ apiKey: 'sk_case_YOUR_API_KEY' });

// 1. Upload audio to vault
const upload = await client.vault.upload('vault_abc123', {
  filename: 'deposition.mp3',
  contentType: 'audio/mpeg'
});
// Upload file to upload.uploadUrl via PUT

// 2. Start transcription
const job = await client.voice.transcription.create({
  vault_id: 'vault_abc123',
  object_id: upload.objectId,
  speaker_labels: true
});

console.log(job.id);  // tr_xyz789
Response
{
  "id": "tr_rvy731o5zxur0dg72sh3mjar",
  "status": "processing",
  "vault_id": "vault_abc123",
  "source_object_id": "obj_xyz789"
}

​
Get Results (Vault Mode)

const result = await client.voice.transcription.retrieve('tr_rvy731o5zxur0dg72sh3mjar');

if (result.status === 'completed') {
  console.log(result.result_object_id);  // Transcript stored here
  console.log(result.word_count);        // 594
  console.log(result.confidence);        // 97

  // Download transcript from vault
  const transcript = await client.vault.objects.download(
    result.vault_id,
    result.result_object_id
  );
}
Response (completed)
{
  "id": "tr_rvy731o5zxur0dg72sh3mjar",
  "status": "completed",
  "vault_id": "vault_abc123",
  "source_object_id": "obj_xyz789",
  "result_object_id": "obj_abc456",
  "audio_duration": 238,
  "word_count": 594,
  "confidence": 97
}
Vault Mode Benefits:
  • Transcript automatically saved to your vault
  • No webhook setup required
  • Simpler polling with result_object_id
  • Audio stored securely in your vault

​
Direct URL Mode

For audio hosted elsewhere, provide a public URL directly. 
import Casedev from 'casedev';

const client = new Casedev({ apiKey: 'sk_case_YOUR_API_KEY' });

const job = await client.voice.transcription.create({
  audio_url: 'https://storage.example.com/deposition.m4a',
  speaker_labels: true,
  auto_chapters: true
});

console.log(job.id);  // Poll this for results
Response
{
  "id": "474e21cf-fd65-45d4-97fd-87558f7caf9b",
  "status": "queued",
  "audio_url": "https://storage.example.com/deposition.m4a",
  "created_at": "2025-11-04T09:15:30Z"
}

​
Parameters

​
Vault Mode

ParameterTypeRequiredDescription
vault_idstringYesVault containing the audio file
object_idstringYesObject ID of the audio file
formatstringNoOutput format: json (default) or text
speaker_labelsbooleanNoIdentify different speakers
language_codestringNoLanguage code (auto-detected if omitted)

​
Direct URL Mode

ParameterTypeRequiredDescription
audio_urlstringYesURL to audio/video file (max 5GB, 10 hours)
webhook_urlstringNoURL for completion notification

​
Shared Options

ParameterTypeDefaultDescription
speaker_labelsbooleanfalseIdentify different speakers
speakers_expectednumber—Expected number of speakers
language_codestringautoLanguage code (en, es, fr, de, etc.)
punctuatebooleantrueAdd punctuation
format_textbooleantrueFormat numbers, dates, etc.
word_boostarray—Boost specific words (e.g., legal terms)
auto_highlightsbooleanfalseDetect key phrases
content_safety_labelsbooleanfalseFlag sensitive content

​
Get Results (Direct URL Mode)

const result = await client.voice.transcription.retrieve(jobId);

if (result.status === 'completed') {
  console.log(result.text);  // Full transcript

  // With speaker labels
  for (const utterance of result.utterances) {
    console.log(`${utterance.speaker}: ${utterance.text}`);
  }
}
Response (completed)
{
  "id": "474e21cf-fd65-45d4-97fd-87558f7caf9b",
  "status": "completed",
  "audio_duration": 3847000,
  "confidence": 0.94,
  "text": "Q: Can you state your name for the record?\nA: My name is Dr. Sarah Johnson...",
  "utterances": [
    {
      "speaker": "A",
      "text": "Can you state your name for the record?",
      "start": 120,
      "end": 2450
    },
    {
      "speaker": "B",
      "text": "My name is Dr. Sarah Johnson.",
      "start": 2450,
      "end": 4820
    }
  ],
  "chapters": [
    {
      "headline": "Witness Introduction",
      "summary": "Introduction and witness identification",
      "start": 120,
      "end": 15000
    }
  ]
}

​
Status Values

StatusMeaning
queuedWaiting to start
processingTranscribing
completedDone, results ready
failedError occurred

​
Processing Times

Audio LengthTime
1 minute~15 seconds
10 minutes~1-2 minutes
1 hour~8-10 minutes
3 hours~20-30 minutes

​
Examples

​
Deposition with Speaker Labels (Vault Mode)

TypeScript
// Upload to vault first
const upload = await client.vault.upload('vault_depositions', {
  filename: 'smith-deposition-2024.mp3',
  contentType: 'audio/mpeg'
});

const job = await client.voice.transcription.create({
  vault_id: 'vault_depositions',
  object_id: upload.objectId,
  speaker_labels: true,
  speakers_expected: 4,  // Attorney, witness, court reporter, judge
  word_boost: ['plaintiff', 'defendant', 'objection', 'sustained', 'overruled']
});

// Poll for completion
let result = await client.voice.transcription.retrieve(job.id);
while (result.status === 'processing') {
  await new Promise(r => setTimeout(r, 5000));
  result = await client.voice.transcription.retrieve(job.id);
}

// Transcript is now in vault at result.result_object_id

​
Court Recording (Direct URL with Webhook)

TypeScript
const job = await client.voice.transcription.create({
  audio_url: 'https://storage.example.com/3-hour-hearing.m4a',
  speaker_labels: true,
  webhook_url: 'https://your-app.com/webhooks/transcription'
});
// Results POSTed to your webhook when done

​
Supported Formats

Audio: MP3, M4A, WAV, FLAC, OGG, OPUS, WebM
Video: MP4, WebM, MOV, AVI, MKV (audio track extracted)
Languages: 100+ including English, Spanish, French, German, Chinese, Japanese
Pricing: 0.30/minute.A2−hourdepositioncosts0.30/minute. A 2-hour deposition costs 36.