litellm - 💡(How to fix) Fix [Bug]: Vertex Gemini traffic_type is only stored in _hidden_params and not exposed in normalized proxy response or headers [1 participants]

model_list:
    - model_name: gemini-25-flash-lite-dedicated
      litellm_params:
        model: vertex_ai/gemini-2.5-flash-lite
        vertex_project: os.environ/VERTEXAI_PROJECT
        vertex_location: os.environ/VERTEXAI_LOCATION
        vertex_credentials: os.environ/GOOGLE_APPLICATION_CREDENTIALS
        extra_headers:
          X-Vertex-AI-LLM-Request-Type: dedicated
          custom-llm-provider: vertex_ai

  litellm_settings:
    return_response_headers: true

---

model_list:
    - model_name: gemini-25-flash-lite-dedicated
      litellm_params:
        model: vertex_ai/gemini-2.5-flash-lite
        vertex_project: os.environ/VERTEXAI_PROJECT
        vertex_location: os.environ/VERTEXAI_LOCATION
        vertex_credentials: os.environ/GOOGLE_APPLICATION_CREDENTIALS
        extra_headers:
          X-Vertex-AI-LLM-Request-Type: dedicated
          custom-llm-provider: vertex_ai

  litellm_settings:
    return_response_headers: true

---

=== Request ===
  URL: https://aiplatform.googleapis.com/v1/projects/<redacted-project>/locations/global/publishers/google/models/gemini-2.5-flash-lite:generateContent
  X-Vertex-AI-LLM-Request-Type: dedicated

  === Response Status ===
  HTTP 200

  === Response Headers ===
  HTTP/2 200
  x-vertex-ai-llm-request-type: dedicated
  content-type: application/json; charset=UTF-8
  vary: X-Origin
  vary: Referer
  vary: Origin,Accept-Encoding
  date: <redacted-timestamp>
  server: scaffolding on HTTPServer2
  x-xss-protection: 0
  x-frame-options: SAMEORIGIN
  x-content-type-options: nosniff
  alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
  accept-ranges: none

  === Response Body ===
  {
    "candidates": [
      {
        "content": {
          "role": "model",
          "parts": [
            {
              "text": "I am a large language model, trained by Google."
            }
          ]
        },
        "finishReason": "STOP",
        "avgLogprobs": -0.00013389628888531163
      }
    ],
    "usageMetadata": {
      "promptTokenCount": 12,
      "candidatesTokenCount": 11,
      "totalTokenCount": 23,
      "trafficType": "PROVISIONED_THROUGHPUT",
      "promptTokensDetails": [
        {
          "modality": "TEXT",
          "tokenCount": 12
        }
      ],
      "candidatesTokensDetails": [
        {
          "modality": "TEXT",
          "tokenCount": 11
        }
      ]
    },
    "modelVersion": "gemini-2.5-flash-lite",
    "createTime": "<redacted-timestamp>",
    "responseId": "<redacted-response-id>"
  }