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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. 
# 1. Get upload URL
curl -X POST https://api.case.dev/vault/VAULT_ID/upload \
  -H "Authorization: Bearer sk_case_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"filename": "deposition.mp3", "contentType": "audio/mpeg", "auto_index": false}'

# 2. Upload file to the returned uploadUrl (PUT request)

# 3. Start transcription
curl -X POST https://api.case.dev/voice/transcription \
  -H "Authorization: Bearer sk_case_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "vault_id": "VAULT_ID",
    "object_id": "OBJECT_ID",
    "speaker_labels": true
  }'

casedev vault upload \
  --id $VAULT_ID \
  --filename "deposition.mp3" \
  --content-type "audio/mpeg"

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

import casedev

client = casedev.Casedev(api_key='sk_case_YOUR_API_KEY')

# 1. Upload audio to vault
upload = client.vault.upload('vault_abc123',
    filename='deposition.mp3',
    content_type='audio/mpeg'
)
# Upload file to upload.upload_url via PUT

# 2. Start transcription
job = client.voice.transcription.create(
    vault_id='vault_abc123',
    object_id=upload.object_id,
    speaker_labels=True
)

print(job.id)  # tr_xyz789

upload, _ := client.Vault.Upload(ctx, vaultID, casedev.VaultUploadParams{
	Filename:    casedev.F("deposition.mp3"),
	ContentType: casedev.F("audio/mpeg"),
})
// PUT file to upload.UploadURL via net/http
fmt.Println(upload.ObjectID)
Response
{
  "id": "tr_rvy731o5zxur0dg72sh3mjar",
  "status": "processing",
  "vault_id": "vault_abc123",
  "source_object_id": "obj_xyz789"
}

​
Get Results (Vault Mode)

curl https://api.case.dev/voice/transcription/tr_rvy731o5zxur0dg72sh3mjar \
  -H "Authorization: Bearer sk_case_YOUR_API_KEY"

casedev voice:transcription create \
  --audio-url "https://storage.example.com/recording.mp3" \
  --speaker-labels

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
  );
}

result = client.voice.transcription.retrieve("tr_rvy731o5zxur0dg72sh3mjar")

if result.status == "completed":
    print(result.result_object_id)  # Transcript stored here
    print(result.word_count)        # 594
    print(result.confidence)        # 97

    # Download transcript from vault
    transcript = client.vault.objects.download(
        result.vault_id,
        result.result_object_id
    )

result, _ := client.Voice.Transcription.Get(ctx, "tr_rvy731o5zxur0dg72sh3mjar")
if result.Status == "completed" {
	fmt.Println(result.ResultObjectID)
	content, _ := client.Vault.Objects.Download(ctx, result.VaultID, result.ResultObjectID)
	// content is *http.Response with file body
}
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. 
curl -X POST https://api.case.dev/voice/transcription \
  -H "Authorization: Bearer sk_case_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "audio_url": "https://storage.example.com/deposition.m4a",
    "speaker_labels": true,
    "auto_chapters": true
  }'

casedev voice:transcription create \
  --audio-url "https://storage.example.com/recording.mp3" \
  --speaker-labels

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

import casedev

client = casedev.Casedev(api_key='sk_case_YOUR_API_KEY')

job = client.voice.transcription.create(
    audio_url='https://storage.example.com/deposition.m4a',
    speaker_labels=True
)

print(job.id)  # Poll this for results

job, _ := client.Voice.Transcription.New(ctx, casedev.VoiceTranscriptionNewParams{
	AudioURL:      casedev.F("https://storage.example.com/recording.mp3"),
	SpeakerLabels: casedev.F(true),
})
fmt.Println(job.ID)
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.)
speech_modelsarray["universal-3-pro", "universal-2"]Priority-ordered speech models to use
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)

curl https://api.case.dev/voice/transcription/JOB_ID \
  -H "Authorization: Bearer sk_case_YOUR_API_KEY"

casedev voice:transcription create \
  --audio-url "https://storage.example.com/recording.mp3" \
  --speaker-labels

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}`);
  }
}

result = client.voice.transcription.retrieve(job_id)

if result.status == 'completed':
    print(result.text)  # Full transcript

    # With speaker labels
    for utterance in result.utterances:
        print(f'{utterance.speaker}: {utterance.text}')

job, _ := client.Voice.Transcription.New(ctx, casedev.VoiceTranscriptionNewParams{
	AudioURL:      casedev.F("https://storage.example.com/recording.mp3"),
	SpeakerLabels: casedev.F(true),
})
fmt.Println(job.ID)
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)

casedev voice:transcription create \
  --vault-id vault_depositions \
  --object-id "$OBJECT_ID" \
  --speaker-labels \
  --speakers-expected 4 \
  --word-boost "plaintiff,defendant,objection,sustained,overruled"

// 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

# Upload to vault first
upload = client.vault.upload('vault_depositions',
    filename='smith-deposition-2024.mp3',
    content_type='audio/mpeg'
)

job = client.voice.transcription.create(
    vault_id='vault_depositions',
    object_id=upload.object_id,
    speaker_labels=True,
    speakers_expected=4,
    word_boost=['plaintiff', 'defendant', 'objection', 'sustained', 'overruled']
)

# Poll for completion
result = client.voice.transcription.retrieve(job.id)
while result.status == 'processing':
    import time; time.sleep(5)
    result = client.voice.transcription.retrieve(job.id)

# Transcript is now in vault at result.result_object_id

upload, _ := client.Vault.Upload(ctx, "vault_depositions", casedev.VaultUploadParams{
	Filename:    casedev.F("smith-deposition-2024.mp3"),
	ContentType: casedev.F("audio/mpeg"),
})
// PUT file to upload.UploadURL via net/http

job, _ := client.Voice.Transcription.New(ctx, casedev.VoiceTranscriptionNewParams{
	VaultID:          casedev.F("vault_depositions"),
	ObjectID:         casedev.F(upload.ObjectID),
	SpeakerLabels:    casedev.F(true),
	SpeakersExpected: casedev.F(int64(4)),
})
// Poll for completion using client.Voice.Transcription.Get(ctx, job.ID)

​
Court Recording (Direct URL with Webhook)

casedev voice:transcription create \
  --audio-url "https://storage.example.com/3-hour-hearing.m4a" \
  --speaker-labels \
  --webhook-url "https://your-app.com/webhooks/transcription"

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

job = client.voice.transcription.create(
    audio_url='https://storage.example.com/3-hour-hearing.m4a',
    speaker_labels=True
)
# Poll for results when done

job, _ := client.Voice.Transcription.New(ctx, casedev.VoiceTranscriptionNewParams{
	AudioURL:      casedev.F("https://storage.example.com/3-hour-hearing.m4a"),
	SpeakerLabels: casedev.F(true),
	WebhookURL:    casedev.F("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: $0.01/minute. A 2-hour deposition costs $1.20.