Haystack v3.5.0-rc1：新增 OpenAI Decisions 路由组件与多向量检索
原标题：v3.5.0-rc1
AI 摘要
Haystack 发布 v3.5.0-rc1，新增三个基于 OpenAI Decisions API 的组件，用于文本路由、图像路由和文档分类，无需编写提示词即可完成分类与分流。Agent 新增 StructuredOutputHook，可按 Pydantic 模型或 JSON Schema 校验最终回复并在失败时重试，同时引入 StepBudgetReminderHook 提醒剩余步数。检索侧新增 multivector_embedding 字段与 MaxSimRanker，支持 ColBERT 类晚期交互检索。此外默认 OpenAI 模型切换为 gpt-5.6-terra，并有多项升级注意事项。
正文节选
## ⭐️ Highlights ### 🧭 Classify and Route with the OpenAI Decisions API Three new components use the OpenAI Decisions API to make choices about your data without writing a prompt. [`OpenAIDecisionsTextRouter`](https://docs.haystack.deepset.ai/docs/openaidecisionstextrouter) sends text to a named output per label, [`OpenAIDecisionsImageRouter`](https://docs.haystack.deepset.ai/docs/openaidecisionsimagerouter) does the same for images and can send low-confidence decisions to a fallback branch, an