Audio Tool

Speech-to-Text (Transcription)

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

Endpoint

POST /v1/audio/transcribe

Request (multipart/form-data)

Upload an audio file directly:

curl https://api.router9.com/v1/audio/transcribe \
  -H "Authorization: Bearer sk-r9k-your-key" \
  -F [email protected] \
  -F language=en

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",
    "language": "en"
  }'

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
`language`	string	No	Language hint, e.g. `en`, `zh`
`model`	string	No	Override the default transcription model (must be allowlisted)

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"
  }' \
  --output speech.wav

Parameter	Type	Required	Description
`input`	string	Yes	Text to synthesize (max 4,096 characters)
`voice`	string	No	Voice: `alloy`, `echo`, `fable`, `onyx`, `nova`, `shimmer` (default `alloy`)
`model`	string	No	Override the default TTS model (must be allowlisted)

Response

Returns WAV audio as the binary response body with Content-Type: audio/wav.

Text-to-speech requires an audio-output model configured for the tts skill on your deployment. If none is configured, this endpoint returns 503 with "no active model configured".

Audio Skill calls consume credits from your plan's monthly credit allowance — the same allowance used for chat completions. There are no separate per-Skill quotas. See Credits & Usage and Tool Usage & Credits.

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