Audio

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Introduction

• OpenAI format: /v1/audio/speech (TTS), /v1/audio/transcriptions (STT), /v1/audio/translations — compatible with the OpenAI Audio API.
• Gemini native format: POST /v1beta/models/{model}:generateContent with responseModalities: ["AUDIO"] and speechConfig (e.g. gemini-2.5-flash-preview-tts).

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Authentication

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Request examples

curl -X POST "https://api.gravitex.ai/v1/audio/speech" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "tts-1",
    "input": "Hello from GravitexAI.",
    "voice": "alloy",
    "response_format": "mp3"
  }' \
  --output speech.mp3

curl -X POST "https://api.gravitex.ai/v1/audio/transcriptions" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -F file="@audio.mp3" \
  -F model="whisper-1"

curl -X POST "https://api.gravitex.ai/v1/audio/translations" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -F file="@audio.mp3" \
  -F model="whisper-1"

curl -X POST "https://api.gravitex.ai/v1beta/models/gemini-2.5-flash-preview-tts:generateContent" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "parts": [
          {"text": "Say cheerfully: Have a wonderful day!"}
        ]
      }
    ],
    "generationConfig": {
      "responseModalities": ["AUDIO"],
      "speechConfig": {
        "voiceConfig": {
          "prebuiltVoiceConfig": {
            "voiceName": "Kore"
          }
        }
      }
    }
  }'

echo "<base64_data>" | base64 --decode > out.pcm

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Common parameters

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OpenAI format

• model: e.g. tts-1, tts-1-hd
• input: Text to speak (max 4096 chars)
• voice: alloy, echo, fable, onyx, nova, shimmer

• file: Audio file (multipart)
• model: e.g. whisper-1

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Gemini format (TTS)

• model (path): e.g. gemini-2.5-flash-preview-tts, gemini-2.5-pro-preview-tts
• contents[].parts[].text: Text or style instructions
• generationConfig.responseModalities: must include "AUDIO"
• generationConfig.speechConfig.voiceConfig.prebuiltVoiceConfig.voiceName: e.g. Kore, Puck, Charon

• OpenAI Audio API
• Gemini speech generation