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POST
/
api
/
velma-2-stt-batch-english-vfast
Transcribe English audio file
curl --request POST \
  --url https://modulate-developer-apis.com/api/velma-2-stt-batch-english-vfast \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-Key: <api-key>' \
  --form upload_file='@example-file'
{
  "text": "Good morning, everyone.",
  "duration_ms": 2000
}

Documentation Index

Fetch the complete documentation index at: https://docs.modulate.ai/llms.txt

Use this file to discover all available pages before exploring further.

Authorizations

​
X-API-Key
string
header
required

API key for authentication. Your API key must be included in the X-API-Key header for all requests. API keys are tied to your organization and determine your access to models and usage limits.

Body

multipart/form-data
​
upload_file
file
required

Audio file to transcribe. Supported formats: AAC, AIFF, FLAC, MP3, MP4, MOV, OGG, Opus, WAV, WebM. Maximum file size: 100MB. Empty files are rejected.

Content-Type Requirement: The MIME type for this part SHOULD match the audio format being uploaded. Using application/octet-stream is strongly discouraged — the server uses the content type to select the correct audio decoder, and generic binary types may cause intermittent decoding failures or empty responses.

Correct MIME types by format:

  • AAC: audio/aac
  • AIFF: audio/aiff
  • FLAC: audio/flac
  • MP3: audio/mpeg
  • MP4: video/mp4
  • MOV: video/quicktime
  • OGG: audio/ogg
  • Opus: audio/opus
  • WAV: audio/wav
  • WebM: video/webm

Response

Transcription completed successfully

​
text
string
required

The complete transcribed text from the audio file. Text includes automatic capitalization and punctuation. Multiple sentences are separated by appropriate punctuation marks.

Example:

"Hello, this is a sample transcription. It includes proper capitalization and punctuation."

​
duration_ms
integer<int32>
required

The total duration of the processed audio in milliseconds. This value represents the actual audio duration and is used for usage tracking and billing purposes.

Required range: x >= 0
Example:

12500