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D3 The Responses API and Built-in Tools: Function Calling, Web Search / File Search / Computer Use, Structured Output

• What does strict mode in structured outputs solve, what does it not solve, and what must your code still do after receiving the output?结构化输出的 strict 模式解决了什么问题，没解决什么问题？拿到输出之后代码里还要做什么？

  Common in ChinaCommon overseasIntermediate#structured-output#responses-api#validation

  How to reason about it · think before answering

  1. This tests the distinction between well-formed and correct; claiming strict mode removes the need for validation is the classic mistake.
  2. What it solves: strict plus json_schema guarantees the output validates against the schema, so enums are always allowed values, required fields exist and types are right; parsing-layer try/catch and retries can largely go.
  3. What it does not solve: semantics. The verdict is one of two enums but may be wrong; a number is a number but may be invented. Business validation stays.
  4. Then refusals: a safety refusal comes back as a refusal content block, not malformed JSON; unhandled, downstream code crashes on an empty parse, handled, you can separate unwilling from incorrect.
  5. Give the order in code: check refusal, read output_parsed, run business checks (ranges, referenced entities exist, consistency with context), then persist or act.
  6. Expect the follow-up: schema restrictions under strict? Every object needs additionalProperties false and all fields in required, optional fields become nullable; these constraints are exactly what makes the guarantee possible.

  分析过程 · 先想清楚再作答

  1. 这题考的是对「格式正确」与「内容正确」的区分，答成「有了 strict 就不用校验了」是典型的错误。
  2. 先说解决了什么：strict 加 json_schema 保证输出一定能通过 schema 校验——枚举只会是给定值、必填字段一定在、类型不会错，解析层的 try/catch 与重试基本可以删掉。
  3. 再说没解决什么：schema 管不了语义。verdict 一定是两个枚举之一，但判断可能是错的；数字一定是数字，但可能是编的。业务层校验一行不能省。
  4. 然后是拒答分支：模型因安全原因拒绝时返回 refusal 类型的内容块，而不是硬塞一个不合法的 JSON；不处理它，下游会拿到空的解析结果直接崩，处理了才能区分「不愿意」与「没做对」。
  5. 给出代码里的顺序：先查 refusal，再读 output_parsed，再做业务校验（范围、引用是否存在、与上下文是否一致），最后才落库或执行。
  6. 可预期的追问：strict 对 schema 有什么限制？每个对象都要 additionalProperties 为 false、字段都要在 required 里，可选字段用可空类型表达；这些限制正是它能给出保证的原因。

  Key points

  • Solves: output is guaranteed to match the schema, so parsing defenses can go
  • Does not solve: semantic correctness, so business validation stays
  • Check refusal first, then output_parsed, then business checks, then persist
  • Strict requires additionalProperties false and all fields required, optional fields become nullable

  答题要点

  • 解决：输出保证符合 schema，解析层防御代码可以删
  • 没解决：语义正确性，业务校验一行不能省
  • 先查 refusal 再读 output_parsed，再做业务校验，最后落库
  • strict 要求 additionalProperties 为 false、字段全在 required 里，可选用可空类型表达