Create Forced Alignment

POST 
https://api.knoxstudio.ai/v1/forced-alignment

Both file and text are required. Files up to 3GB, audio 100ms–10 hours, transcript at most 675,000 characters. Billed at $0.27/hour. Guide: Forced Alignment.

Request

Query Parameters

Name	Type	Required	Description
enable_logging	Boolean	No	Default true. false requests zero-retention mode.

Request Headers

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

Request Body

Name	Type	Required	Description
file	File	Yes	Audio file to align.
text	String	Yes	Transcript to align. Max 675,000 characters.

cURL Example

curl -X POST https://api.knoxstudio.ai/v1/forced-alignment \
     -H "Authorization: Bearer $KNOXCHAT_API_KEY" \
     -F "file=@speech.wav" \
     -F "text=Hello from Knox. This is forced alignment."

Response

Success Response (200)

JSON:

Name	Type	Description
characters	array	text, start, end, optional loss.
words	array	text, start, end, optional loss.

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.