Create Sound Effect

POST 
https://api.knoxstudio.ai/v1/sound-generation

Generate a clip from text. Duration 0.5–30 seconds. Billed at $0.17/minute (estimated 5s if duration_seconds is omitted). Guide: Sound Effects.

Request

Query Parameters

Name	Type	Required	Description
output_format	String	No	Allowed: mp3_22050_32, mp3_24000_48, mp3_44100_32, mp3_44100_64, mp3_44100_96, mp3_44100_128, mp3_44100_192, pcm_8000, pcm_16000, pcm_22050, pcm_24000, pcm_32000, pcm_44100, pcm_48000, ulaw_8000, alaw_8000, opus_48000_32, opus_48000_64, opus_48000_96, opus_48000_128, opus_48000_192. WAV and mp3_48000_* are not allowed.

Request Headers

Name	Type	Required	Description
Authorization	String	Yes	Bearer <token> Knox API key. xi-api-key is also accepted.
Content-Type	String	Yes	application/json

Request Body

Name	Type	Required	Description
text	String	Yes	Prompt that is converted into a sound effect.
model_id	String	No	Must be eleven_text_to_sound_v2 if set. Default eleven_text_to_sound_v2.
duration_seconds	Number	No	0.5–30. Optional; the model may pick a length.
prompt_influence	Number	No	0–1. Default 0.3. Higher follows the prompt more closely.
loop	Boolean	No	Seamless loop. Only valid for eleven_text_to_sound_v2.

cURL Example

curl -X POST "https://api.knoxstudio.ai/v1/sound-generation?output_format=mp3_44100_128" \
     -H "Authorization: Bearer $KNOXCHAT_API_KEY" \
     -H "Content-Type: application/json" \
     -o sfx.mp3 \
     -d '{
  "text": "Spacious cinematic braam",
  "duration_seconds": 4.5,
  "prompt_influence": 0.3,
  "model_id": "eleven_text_to_sound_v2"
}'

Response

Success Response (200)

The generated audio file. Content-Type follows output_format.

Error Responses

Validation uses HTTP 422:

{
  "detail": [
    {
      "loc": ["body", "field"],
      "msg": "…",
      "type": "value_error"
    }
  ]
}

Other errors use { "detail": "message" }.

Status	When
400	WebSocket path called without Upgrade: websocket.
401	Missing or invalid API key.
402	Insufficient credits.
403	Token is not allowed to use this model.
404	Resource not found.
422	Validation error.
429	Rate limit exceeded.
500	Internal server error.