Per-Response Model Identity Disclosure in Frontier AI APIs: Cross-Vendor Comparison Data (June 2026)

Controlled comparison of per-response model identity disclosure across Google Gemini API and Anthropic Claude API. Google returns model_version and x-gemini-service-tier in every response (8/8 tests). Anthropic returns no equivalent fields (0/4 tests); response.model echoes the requested model without confirming the served model. Demonstrates that routing transparency is technically feasible and its absence is a design choice.针对谷歌Gemini API（Google Gemini API）与Anthropic Claude API（Anthropic Claude API）的逐响应模型身份披露情况开展受控对比实验。谷歌在全部8次测试的所有响应结果中均返回了model_version（模型版本）与x-gemini-service-tier（x-gemini服务层级）字段；而Anthropic在4次测试中均未返回等效字段（0/4），且其响应中的model字段仅会回显用户请求的模型，未对实际部署的服务模型进行确认。本实验表明，路由透明度在技术层面具备可行性，而未提供该透明度则属于一项设计选择。