Audio Tool

Speech-to-Text (Transcription)

Transcribe audio files to text. Compatible with the OpenAI Whisper API format.

Endpoint

POST /v1/audio/transcriptions

Request (multipart/form-data)

Upload an audio file directly:

curl https://api.router9.com/v1/audio/transcriptions \
  -H "Authorization: Bearer sk-r9k-your-key" \
  -F [email protected] \
  -F prompt="Technical meeting about API design"

Request (JSON)

Provide audio via URL or base64:

curl https://api.router9.com/v1/audio/transcribe \
  -H "Authorization: Bearer sk-r9k-your-key" \
  -H "Content-Type: application/json" \
  -d '{
    "mediaUrl": "https://example.com/audio.mp3",
    "prompt": "Technical meeting"
  }'

Parameter	Type	Required	Description
`file`	binary	One of file/mediaUrl/mediaBase64	Audio file (multipart upload)
`mediaUrl`	string	One of file/mediaUrl/mediaBase64	URL to audio file
`mediaBase64`	string	One of file/mediaUrl/mediaBase64	Base64-encoded audio
`prompt`	string	No	Context hint for transcription

Response

{
  "success": true,
  "tool": "audio.transcribe",
  "result": {
    "fullText": "Hello everyone, today we'll discuss the new API design."
  }
}

Text-to-Speech (Synthesis)

Convert text to spoken audio.

Endpoint

POST /v1/audio/synthesize

Request

curl https://api.router9.com/v1/audio/synthesize \
  -H "Authorization: Bearer sk-r9k-your-key" \
  -H "Content-Type: application/json" \
  -d '{
    "input": "Hello, welcome to Router9!",
    "voice": "nova",
    "response_format": "mp3"
  }' \
  --output speech.mp3

Parameter	Type	Required	Description
`input`	string	Yes	Text to synthesize (max 4,096 characters)
`voice`	string	No	Voice selection (provider-specific)
`response_format`	string	No	Output format: `mp3`, `wav`, etc.

Response

Returns the audio file binary with the appropriate Content-Type header (e.g., audio/mp3).

Quotas

Plan	ASR (Speech-to-Text)	TTS (Text-to-Speech)
Free	10/period	10/period
Assistant	200/period	200/period
Engineer	5,000/period	5,000/period

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