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APIsLegacySpeech to Text Translate

REST

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Speech to Text Translation API

This API automatically detects the input language, transcribes the speech, and translates the text to English.

Available Options:

  • REST API (Current Endpoint): For quick responses under 30 seconds with immediate results
  • Batch API: For longer audio files Follow this documentation
    • Supports diarization (speaker identification)

Note:

  • Pricing differs for REST and Batch APIs
  • Diarization is only available in Batch API with separate pricing
  • Please refer to here for detailed pricing information

Authentication

api-subscription-keystring
API Key authentication via header

Request

This endpoint expects a multipart form containing a file.
filefileRequired

The audio file to transcribe. Supported formats include WAV, MP3, AAC, AIFF, OGG, OPUS, FLAC, MP4/M4A, AMR, WMA, WebM, and PCM formats. The API automatically detects most codec formats, but for PCM files (pcm_s16le, pcm_l16, pcm_raw), you must specify the input_audio_codec parameter. PCM files are supported only at 16kHz sample rate. Works best at 16kHz. Multiple channels will be merged.

promptstring or nullOptional
Conversation context can be passed as a prompt to boost model accuracy. However, the current system is at an experimentation stage and doesn't match the prompt performance of large language models.
modelenumOptional

Model to be used for speech to text translation.

  • saaras:v2.5 (default): Translation model that translates audio from any spoken Indic language to English.
    • Example: Hindi audio → English text output

For the latest model (saaras:v3), use the /speech-to-text endpoint with mode="translate".

Allowed values:
input_audio_codecenumOptional

Audio codec/format of the input file. Our API automatically detects all codec formats, but for PCM files specifically (pcm_s16le, pcm_l16, pcm_raw), you must pass this parameter. PCM files are supported only at 16kHz sample rate.

Response

Successful Response
request_idstring or null
transcriptstring
Transcript of the provided speech
language_codeenum or null

This will return the BCP-47 code of language spoken in the input. If multiple languages are detected, this will return language code of most predominant spoken language. If no language is detected, this will be null

diarized_transcriptobject or nullOptional

Diarized transcript of the provided speech. Always null on the REST API — diarization is only available via the Batch API.

language_probabilitydouble or nullOptional

Float value (0.0 to 1.0) indicating the probability of the detected language being correct. Higher values indicate higher confidence.

When it returns a value:

  • When language_code is not provided in the request
  • When language_code is set to unknown

When it returns null:

  • When a specific language_code is provided (language detection is skipped)

The parameter is always present in the response.

Errors

400
Bad Request Error
403
Forbidden Error
422
Unprocessable Entity Error
429
Too Many Requests Error
500
Internal Server Error
503
Service Unavailable Error