Text-to-Speech & Voice Cloning Assistant (via Verbatik)

Autonomously generate speech, clone voices, and manage audio via the Verbatik API.

Setup

1. Create a Verbatik account at api.verbatik.com
2. Top up your prepaid balance (Settings → Billing)
3. Generate an API key (Settings → API Keys)
4. Store your API key:

   VERBATIK_API_KEY=vbt_your_api_key_here
   

Auth

All requests use Bearer token:

Authorization: Bearer <VERBATIK_API_KEY>

Base URL: https://api.verbatik.com

MCP (Model Context Protocol)

Verbatik also exposes an MCP server for direct AI assistant integration. Endpoint:

https://api.verbatik.com/api/mcp/mcp

Supports OAuth 2.1 (one-click connect in Claude Desktop) and API key auth via mcp-remote bridge.

Core Workflow

1. List Available Voices

GET /api/v1/voices

Query params:

• language — filter by language code (e.g. en-US, fr-FR)
• gender — Male, Female, or Neutral
• search — search by voice name

Returns array of voices with id (slug), name, gender, language_code, language_name, is_neural, sample_url, styles.

2. Text-to-Speech (Pre-trained Voices)

POST /api/v1/tts
Content-Type: text/plain
Authorization: Bearer <key>
X-Voice-ID: jenny-en-us
X-Store-Audio: true

Hello, this is a test of the Verbatik text-to-speech API.

Headers:

• Content-Type — text/plain or application/ssml+xml for SSML
• X-Voice-ID — voice slug (e.g. jenny-en-us). Defaults to Jenny if omitted
• X-Store-Audio — true to get a stored URL back, false for binary audio stream

Max text length: 50,000 characters. Large texts are automatically chunked.

Cost: $0.002 per 1,000 characters

Response (when X-Store-Audio: true):

{
  "success": true,
  "audio_url": "https://...",
  "characters_processed": 52,
  "chunks_processed": 1,
  "response_time_ms": 1200,
  "cost_cents": 1
}

Response (when X-Store-Audio: false): Binary audio with metadata in response headers (X-Characters-Processed, X-Cost-Cents, X-Balance-Cents).

3. Clone a Voice

POST /api/v1/voice-training
Content-Type: application/json
Authorization: Bearer <key>

{
  "audio_url": "https://example.com/sample.mp3",
  "name": "My Voice",
  "noise_reduction": true,
  "volume_normalization": true,
  "preview_text": "Hello, this is a preview of my cloned voice!"
}

Requirements:

• Audio must be at least 10 seconds of speech
• Supported formats: .mp3, .wav (max 20MB)
• Cost: $3.00 per clone

Response:

{
  "success": true,
  "voice_id": "uuid-here",
  "name": "My Voice",
  "fal_voice_id": "...",
  "preview_url": "https://...",
  "cost_cents": 300
}

4. Generate Speech with Cloned Voice

POST /api/v1/voice-cloning
Content-Type: text/plain
Authorization: Bearer <key>
X-Voice-ID: <cloned_voice_uuid>
X-Store-Audio: true

Hello from my cloned voice!

Optional headers for voice control:

• X-Speed — 0.5 to 2.0 (default: 1)
• X-Volume — 0 to 10 (default: 1)
• X-Pitch — -12 to 12 (default: 0)
• X-Emotion — happy, sad, angry, fearful, disgusted, surprised, neutral
• X-Format — mp3, pcm, flac (default: mp3)
• X-Language-Boost — language to enhance (e.g. English, French, Japanese)
• X-Sample-Rate — 8000, 16000, 22050, 24000, 32000, 44100
• X-Bitrate — 32000, 64000, 128000, 256000

Voice modification (Speech 2.8 Turbo):

• X-Voice-Modify-Pitch — -100 to 100
• X-Voice-Modify-Intensity — -100 to 100
• X-Voice-Modify-Timbre — -100 to 100

Supports interjection tags in text: (laughs), (sighs), (coughs), (clears throat), (gasps), (sniffs), (groans), (yawns)

Supports pause markers: <#x#> where x = 0.01–99.99 seconds

Max text length: 5,000 characters. Cost: $0.10 per 1,000 characters

5. Manage Cloned Voices

List all cloned voices:

GET /api/v1/my-voices

Optional query param: status — pending, ready, or failed

Get a specific voice:

GET /api/v1/my-voices/<voice_id>

Delete a voice:

DELETE /api/v1/my-voices/<voice_id>

6. Preview a Pre-trained Voice

GET /api/v1/preview/<voice_slug>

Returns binary audio preview. No auth required. Cached for 24 hours.

Pricing

All usage is deducted from your prepaid balance. Auto top-up is available.

Error Handling

Tips

• Always use X-Store-Audio: true when you need a shareable URL — binary mode is for streaming
• Use voice slugs (e.g. jenny-en-us) not internal IDs for pre-trained voices
• Use UUIDs from voice-training or my-voices for cloned voices
• Clone voices with clean audio (minimal background noise) for best results
• Use noise_reduction: true when cloning from imperfect audio
• Cloned voices expire after 7 days of inactivity — Verbatik auto-refreshes them via cron
• Estimate costs before large batches with the estimate_cost MCP tool
• Check your balance before bulk operations to avoid 402 errors
• Use emotion and speed controls on cloned voices for more natural output
• SSML is supported for pre-trained voices — use Content-Type: application/ssml+xml