Transcription

LLMGateway exposes a dedicated /v1/audio/transcriptions endpoint for speech-to-text. It transcribes audio files into text with word-level timestamps, optional speaker diarization, and inverse text normalization (spoken numbers and currencies formatted in their written form).

Use it when you want to:

• Turn recordings, voicemails, or podcast episodes into text
• Generate captions or searchable transcripts with per-word timing
• Feed spoken content into a downstream model or RAG pipeline

For the full request and response schema, see the API reference.

Endpoint

POST https://api.llmgateway.io/v1/audio/transcriptions

Authenticate with your LLMGateway API key:

-H "Authorization: Bearer $LLM_GATEWAY_API_KEY"

The current model is grok-stt-1-0, billed at $0.10 per hour of input audio (against the duration reported by the provider).

Parameters

The request body is multipart/form-data. Either file or url must be provided.

Response

The response includes the full transcript, audio duration, and word-level timestamps:

{
	"text": "The balance is $167,983.15.",
	"language": "English",
	"duration": 3.45,
	"words": [
		{ "text": "The", "start": 0.24, "end": 0.48 },
		{ "text": "balance", "start": 0.48, "end": 0.96 },
		{ "text": "is", "start": 0.96, "end": 1.12 },
		{ "text": "$167,983.15.", "start": 1.12, "end": 3.2 }
	]
}

curl

curl -X POST "https://api.llmgateway.io/v1/audio/transcriptions" \
  -H "Authorization: Bearer $LLM_GATEWAY_API_KEY" \
  -F model=grok-stt-1-0 \
  -F language=en \
  -F file=@audio.mp3

Transcribing from a URL

curl -X POST "https://api.llmgateway.io/v1/audio/transcriptions" \
  -H "Authorization: Bearer $LLM_GATEWAY_API_KEY" \
  -F model=grok-stt-1-0 \
  -F url="https://example.com/audio.mp3"