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POST
Transcribe audio

Authorizations

Authorization
string
header
required

API key in the Authorization header: Bearer sk_hopper_... Keys are minted in the dashboard at withhopper.com/console/keys and shown once at creation. WebSocket connections also accept ?api_key=.

Body

multipart/form-data
file
file
required

Raw PCM16 mono or WAV audio. Compressed formats return 400 unsupported_audio_format.

model
string
required

STT model id, e.g. nemotron-asr.

language
string

Language hint, forwarded to the model.

keyterms
string

Terms to bias recognition toward, forwarded to the model.

sample_rate
enum<integer>
default:16000

Sample rate of the submitted audio.

Available options:
8000,
16000,
22050,
24000,
44100,
48000

Response

Transcript with word timestamps. duration_seconds = bytes / (sample_rate x 2), rounded to ms.

text
string
words
object[]
duration_seconds
number