> For the complete documentation index, see [llms.txt](https://yeasy.gitbook.io/context_engineering_guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://yeasy.gitbook.io/context_engineering_guide/fu-lu/volatile_facts.md).

# 附录 E：快变事实核验表

> Last verified: 2026-06-17. 本表约束上下文窗口、模型价格、协议、RAG/Agent runtime 等高波动事实；模型上下文窗口口径与第 2.4 节的官方快照同步。

| 类别                       | 当前维护口径                                                                                                                | 权威入口                                                                                                                                                                                                                                                                                                                                                                                                   | 编辑要求                                                                                                  |
| ------------------------ | --------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------- |
| 模型上下文窗口                  | OpenAI、Claude（2026-06-09 起含 Fable 5 / Mythos 5 新一代；2026-06-12 起两者访问暂停）、Gemini、Llama、DeepSeek 等上下文窗口只写 dated snapshot。 | [OpenAI Models](https://developers.openai.com/api/docs/models/all/), [Claude Models](https://platform.claude.com/docs/en/about-claude/models/overview), [Fable/Mythos access statement](https://www.anthropic.com/news/fable-mythos-access), [Gemini Models](https://ai.google.dev/gemini-api/docs/models), [Meta Llama model card](https://www.llama.com/docs/model-cards-and-prompt-formats/llama4/) | 正文应强调设计策略，具体窗口放表格并标日期；“最强/旗舰”须区分发布规格、当前可用性、Fable 5（全系）与 Opus 4.8（Opus 档）；Llama 4 上下文以模型卡为准，避免产品页摘要误导。 |
| 成本与缓存                    | token 单价、prompt cache、batch、long context 价格以官方 pricing 为准。                                                            | OpenAI / Anthropic / Google 官方 pricing                                                                                                                                                                                                                                                                                                                                                                 | ROI 示例必须标注假设，不写成通用收益。                                                                                 |
| MCP / tool runtime       | MCP transport、OAuth、server/client 能力以规范版本为准。                                                                          | [MCP Spec](https://modelcontextprotocol.io/specification), [MCP Roadmap](https://blog.modelcontextprotocol.io/posts/2026-mcp-roadmap/)                                                                                                                                                                                                                                                                 | 先打开 latest 入口，再记录实际解析到的规范版本 URL；协议字段必须跟该版本绑定。                                                         |
| Agent SDK / coding agent | Claude Code、OpenAI Agents、Codex、Gemini tooling 以官方文档为准。                                                               | 各厂商官方 developer docs                                                                                                                                                                                                                                                                                                                                                                                   | 不把某产品内部实现写成通用事实。                                                                                      |
| Benchmark / eval         | 长上下文、RAG、Agent benchmark 只作为 dated snapshot。                                                                          | 官方论文、benchmark 仓库                                                                                                                                                                                                                                                                                                                                                                                      | 避免把单一榜单当生产效果承诺。                                                                                       |


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