Skip to main content

​
POST /v1/audio/transcriptions

Transcribes an audio file into text. The request body must be sent as multipart/form-data with the audio file included as a form field. This endpoint maps to the createTranscription operation and is compatible with the OpenAI Whisper API.

​
Request headers

​
x-portkey-provider
string
The provider to route the request to (e.g. openai). Required when not using a config.
​
x-portkey-api-key
string
Your provider API key.
​
x-portkey-config
string
A JSON config object or config ID that defines routing, fallbacks, retries, and more.
​
x-portkey-virtual-key
string
A virtual key ID from Portkey Cloud.

​
Request body

This endpoint accepts multipart/form-data. The audio file must be uploaded as a file field named file.
​
file
file
required
The audio file to transcribe. Supported formats: flac, mp3, mp4, mpeg, mpga, m4a, ogg, wav, webm. Maximum file size is 25 MB.
​
model
string
required
The speech-to-text model to use (e.g. whisper-1, gpt-4o-transcribe).
​
language
string
The language of the audio, in ISO-639-1 format (e.g. en, fr, de). Providing the language improves accuracy and latency.
​
prompt
string
Optional text to guide the model’s style or provide context. The prompt should match the language of the audio.
​
response_format
string
default:"json"
The format of the transcription output. One of json, text, srt, verbose_json, or vtt.
​
temperature
number
default:"0"
Sampling temperature between 0 and 1. Higher values produce more varied output. Set to 0 for deterministic transcription.
​
timestamp_granularities
string[]
The granularity of timestamps to include. Requires response_format to be verbose_json. Accepts word and/or segment.

​
Response

The response format depends on the response_format parameter. json (default)
​
text
string
The transcribed text.
verbose_json
​
text
string
The full transcribed text.
​
language
string
The detected language of the audio.
​
duration
number
The duration of the audio file in seconds.
​
segments
object[]
Segment-level transcription data, present when timestamp_granularities includes segment.
​
words
object[]
Word-level transcription data, present when timestamp_granularities includes word.
text, srt, vtt — Plain-text or subtitle format strings.

​
Code examples

curl http://localhost:8787/v1/audio/transcriptions \
  -H "x-portkey-provider: openai" \
  -H "x-portkey-api-key: $OPENAI_API_KEY" \
  -F "model=whisper-1" \
  -F "[email protected]" \
  -F "language=en" \
  -F "response_format=json"

Build docs developers (and LLMs) love

Get started for freeTalk to us