Gemini TTS

Authorization: Bearer sk-xxxxxxxxxx

POST https://api.gravitex.ai/v1beta/models/{model}:generateContent

curl "https://api.gravitex.ai/v1beta/models/gemini-3.8-flash-tts:generateContent" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "欢迎收听今天的科技早报。<short pause>第一条,研究人员宣布在室温超导材料上取得突破。",
            "speech_metadata": { "speaker": "Host", "style": "新闻播报,清晰而热情" }
          }
        ]
      }
    ],
    "generationConfig": {
      "responseModalities": ["AUDIO"],
      "speechConfig": {
        "voiceConfig": {
          "prebuiltVoiceConfig": { "voiceName": "Kore" }
        }
      }
    }
  }'

curl "https://api.gravitex.ai/v1beta/models/gemini-3.1-flash-tts-preview:generateContent" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          { "text": "用欢快的语气说:祝你今天过得愉快!" }
        ]
      }
    ],
    "generationConfig": {
      "responseModalities": ["AUDIO"],
      "speechConfig": {
        "voiceConfig": {
          "prebuiltVoiceConfig": { "voiceName": "Kore" }
        }
      }
    }
  }'

{
  "candidates": [
    {
      "content": {
        "role": "model",
        "parts": [
          { "inlineData": { "mimeType": "audio/wav", "data": "UklGRi4..." } }
        ]
      },
      "finishReason": "STOP"
    }
  ],
  "usageMetadata": {
    "promptTokenCount": 5,
    "candidatesTokenCount": 1680,
    "totalTokenCount": 1685,
    "candidatesTokensDetails": [ { "modality": "AUDIO", "tokenCount": 1680 } ]
  },
  "modelVersion": "gemini-3.8-flash-tts",
  "responseId": "xxxx",
  "createTime": "2026-10-10T10:00:00Z"
}

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

import base64, json, struct

resp = json.load(open("response.json"))
inline = resp["candidates"][0]["content"]["parts"][0]["inlineData"]
pcm = base64.b64decode(inline["data"])

# mimeType 形如 audio/l16;codec=pcm;rate=24000,从 rate= 解析
rate = 24000
for part in inline["mimeType"].split(";"):
    if part.strip().startswith("rate="):
        rate = int(part.strip()[5:])

header = (b"RIFF" + struct.pack("<I", 36 + len(pcm)) + b"WAVE"
          + b"fmt " + struct.pack("<IHHIIHH", 16, 1, 1, rate, rate * 2, 2, 16)
          + b"data" + struct.pack("<I", len(pcm)))
open("speech.wav", "wb").write(header + pcm)

{
  "contents": [
    {
      "role": "user",
      "parts": [
        { "text": "今晚的主题是人工智能安全。", "speech_metadata": { "speaker": "Alice", "style": "沉稳的主持人" } },
        { "text": "我先说结论:<short pause>最大的风险在部署环节。", "speech_metadata": { "speaker": "Bob", "style": "轻快的学者" } }
      ]
    }
  ],
  "generationConfig": {
    "responseModalities": ["AUDIO"],
    "speechConfig": {
      "voiceConfig": { "prebuiltVoiceConfig": { "voiceName": "Puck" } }
    }
  }
}

GET https://api.gravitex.ai/v1beta/voices?model={model}

curl -G "https://api.gravitex.ai/v1beta/voices?model=gemini-3.1-flash-tts-preview" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  --data-urlencode "language_code=zh-CN" \
  --data-urlencode "gender=female" \
  --data-urlencode "search=warm"

{
  "voices": [
    {
      "id": "achernar",
      "type": "VOICE_TYPE_PREBUILT",
      "display_name": "Achernar",
      "language_code": "en-US",
      "region_code": "US",
      "accent": "General American",
      "persona": "Storyteller & Narrator",
      "context": "Content & Media",
      "gender": "female",
      "pitch": "PITCH_HIGH",
      "description": "Soft, calm, and soothing voice with a higher pitch. Recommended for quiet or personal storytelling."
    },
    {
      "id": "achird",
      "type": "VOICE_TYPE_PREBUILT",
      "display_name": "Achird",
      "language_code": "en-US",
      "region_code": "US",
      "accent": "General American",
      "persona": "Companion & Peer",
      "context": "Conversational / Edu",
      "gender": "male",
      "pitch": "PITCH_LOW",
      "description": "Friendly, approachable, and warm voice with a lower-middle pitch. Recommended for casual walkthroughs or vlogs."
    }
  ],
  "next_page_token": "achird|en-US"
}