Voice clone preview

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Endpoint

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Request parameters

• model string required
  Model to use for cloning. Supports stepaudio-2.5-tts.
• file_id string required
  Reference audio file ID. Obtain via file upload; set purpose to storage.
• text string optional
  Transcript of the reference audio. If omitted, automatic speech recognition is used. For best results, we recommend providing the transcript.
• sample_text string required
  Text to synthesize for the preview. Recommended length: under 50 characters.
• response_format string optional
  Audio format for the response. Options: wav, mp3, flac, opus, pcm. Default: mp3.
• speed float optional
  Speaking rate. Range: 0.5–2.0. Default: 1.0.
• volume float optional
  Volume level. Range: 0.1–2.0. Default: 1.0.
• instruction string optional
  Global natural-language guidance for the stepaudio-2.5-tts model. Sets the overall emotional tone and character for the audio. Max length: 200 characters.
• sample_rate integer optional
  Sample rate in Hz. Options: 8000, 16000, 22050, 24000, 48000. Default: 24000. Higher values produce better quality but larger files.
• pronunciation_map object array optional
  Custom pronunciation rules for specific characters or symbols.
  • tone string required
    Pronunciation mapping separated by /. Example: ["word/wɜːrd"].
• markdown_filter bool optional
  Whether to enable Markdown filtering for the input text.

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Response

• sample_text string
  The text used for the preview audio.
• sample_audio string
  Preview audio in base64 format (WAV). Convert to a file for playback.
• request_id string
  Unique identifier for this request.

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Example

curl -L 'https://api.stepfun.ai/v1/audio/voices/preview' \
-H 'Content-Type: application/json' \
-H "Authorization: Bearer $STEP_API_KEY" \
-d '{
    "file_id": "file-Ckyl3cV09A",
    "model": "stepaudio-2.5-tts",
    "text": "StepFun intelligence, amplifying every possibility tenfold",
    "sample_text": "Nice weather today",
    "instruction": "Gentle tone, slightly slow pace"
}'