x-goog-api-key: YOUR_API_KEY
content-type: application/json

POST /v1beta/models/{model}:generateContent

curl --request POST \
  --url https://your-domain/v1beta/models/gemini-3.1-pro-preview:generateContent \
  --header 'x-goog-api-key: YOUR_API_KEY' \
  --header 'content-type: application/json' \
  --data '{
    "contents": [{
      "role": "user",
      "parts": [{"text": "只回复 OK"}]
    }],
    "generationConfig": {"maxOutputTokens": 8}
  }'

{
  "candidates": [
    {
      "content": {
        "role": "model",
        "parts": [
          {"text": "OK"}
        ]
      },
      "finishReason": "STOP"
    }
  ],
  "usageMetadata": {
    "promptTokenCount": 8,
    "candidatesTokenCount": 1,
    "totalTokenCount": 9
  }
}