Changes on 2026-09-23

1. **Understand the Goal**: The user wants an analysis of a documentation diff for `build-with-claude/prompt-caching.md`. The analysis needs to be concise, in markdown format, written in Chinese, and structured with four specific sections: Overall Summary, Key Themes, Impact level, and Action items. 2. **Analyze the Diff**: * **File**: `build-with-claude/prompt-caching.md` * **Change**: Added `exclude="shell:cURL, shell:CLI, typescript, csharp, go, java, php, ruby"` to two `<CodeGroup>` components. * **Context**: The `<CodeGroup>` components contain Python code snippets showing the migration from the beta API (`client.beta.prompt_caching.messages.create(**params)`) to the stable API (`client.messages.create(**params)`). * **Meaning of `exclude`**: In Docusaurus (which Anthropic docs likely use based on `<CodeGroup>`), `exclude` hides specific tabs/languages. Here, it hides cURL, CLI, TypeScript, C#, Go, Java, PHP, and Ruby. It effectively means *only* Python is shown for this specific troubleshooting/code migration section. * **Why it matters**: Previously, the code group might have shown empty or irrelevant tabs for other languages, or the migration instruction was specifically about Python (as indicated by the error message `AttributeError: 'Beta' object...`), so showing only Python makes the documentation more precise and less confusing. It doesn't change the API behavior, just the doc rendering. 3. **Draft the Analysis (Iterative refinement)**: * **Overall Summary**: The documentation updated the code examples for Prompt Caching migration by restricting the code group to only show the Python snippet, removing irrelevant language tabs. * *Draft (Chinese)*: 文档更新了 Prompt Caching 的代码示例，通过排除其他语言的标签页，使其仅在相关位置显示 Python 代码片段，从而提高文档精确度。 * **Key Themes**: * Documentation clarity/UI refinement. * Context-specific code snippets (only show what's relevant to the specific error). * *Draft (Chinese)*: * 文档精确度提升：移除与特定错误无关的编程语言标签。 * UI 优化：避免在非适用语言的代码块中显示空白或误导性内容。 * **Impact level**: Low. * *Reasoning*: It's purely a UI/documentation rendering change. It doesn't affect API functionality, SDK behavior, or developer workflows (they already knew to use the stable API if they upgraded, this just makes the docs cleaner). * *Draft (Chinese)*: Low (低)。理由：纯粹是文档界面的显示优化，不涉及 API 功能、SDK 行为或开发者代码逻辑的变更。 * **Action items for developers**: None really, maybe just note the cleaner docs. But I need bullets. Let's say "No action required, just be aware of the documentation improvements." * *Draft (Chinese)*: * 无需采取任何代码行动。 * （可选）如果在其他语言中遇到类似 Beta 前缀问题，参考 Python 的迁移思路，即直接使用稳定版 API 替代带有 `beta.prompt_caching` 的调用。 4. **Review and Refine (Formatting and Conciseness)**: Ensure it strictly follows the requested markdown format and stays concise. * Overall Summary: 针对Prompt Caching的Beta迁移说明，文档通过`exclude`属性隐藏了除Python以外的其他语言标签页，确保特定错误排查指南仅展示相关代码。 * Key Themes: * 文档精确性提升：根据特定语言的错误信息（Python的AttributeError）精准匹配代码示例。 * 展示优化：避免在其他语言标签下显示空白或不相关的代码。 * Impact level: Low。理由：仅涉及文档UI渲染逻辑的微调，未改变任何API接口或SDK功能。 * Action items: * 无需修改任何现有代码。 * 遇到Beta API迁移问题时，直接移除`beta.prompt_caching`前缀调用稳定版即可（跨语言通用逻辑）。 5. **Final Polish (Chinese)**: Looks good and accurate to the technical change (Docusaurus CodeGroup `exclude` prop).

Let me analyze the documentation changes across these 4 pages. 1. **claude-code-on-the-web.md**: Cloud sessions changed from "research preview" to "available" - indicating general availability 2. **memory.md**: AGENTS.md support improvements - removing restrictions around Bedrock/telemetry-disabled sessions for v2.1.281+, simplifying the troubleshooting steps 3. **streaming.md**: Excluding cURL from CodeGroup examples 4. **CHANGELOG.md**: Massive changelog for v2.1.281 with many fixes and some new features Key themes: - Cloud sessions GA - AGENTS.md support expanded (no longer restricted by Bedrock/telemetry in v2.1.281+) - v2.1.281 release with significant stability fixes - Streaming docs cleanup Impact: High - the v2.1.281 release has many important bug fixes that affect stability, plus AGENTS.md now works in more environments.

1. **Analyze the Request:** * **Role:** World-class programmer analyzing documentation changes. * **Input:** A batch of diffs from 19 pages of documentation (presumably Anthropic/Claude API docs). * **Output Format:** Markdown analysis with four specific sections: 1. Overall Summary. 2. Key Themes. 3. Impact Level with reasoning. 4. Action Items for developers (max 5). * **Language:** Chinese. 2. **Scan and Analyze the Diffs (Page by Page):** * `about-claude/models/overview.md`: * Change: "Show all details" -> "Additional details". * Significance: Very minor UI/Documentation text update. Likely accessibility or naming convention cleanup. * `about-claude/pricing.md`: * Change: Markdown table formatting tweaks (column widths, alignment). No actual price changes visible in the snippet provided (it cuts off in the diff view but usually implies data consistency or formatting). *Correction*: Looking closer, it looks like the diff is mostly whitespace/formatting alignment for the table. The content (prices) seems identical at the top. * `about-claude/model-deprecations.md`: * Change: Removed the Note about "Claude Mythos Preview" being deprecated/migration guide. * Significance: Cleanup of old migration warnings. Mythos Preview is old news; Mythos 5/5.1 are current. * `api/messages.md` (and `count_tokens.md`, `batches/create.md`): * Change: Added `claude-opus-5-5` to the list of models. Description: "Powerful intelligence for coding, knowledge work, and long-running agents". * Count: Added in `messages` (multiple times), `count_tokens`, `batches/create`. * Significance: **Major Feature**. Claude Opus 5.5 is now generally available or prominently supported in the API. * `api/models/list.md` & `api/beta/files/upload.md`: * Change: Added two new beta headers/versions: `inline-tools-2026-09-15` and `mcp-client-2026-09-15`. * Significance: New capabilities for Inline Tools and MCP (Model Context Protocol) clients coming in Sept 2026. * `build-with-claude/extended-thinking.md`: * Change: Updated the condition for migrating off `type: "enabled"`. Now says "Claude 4.7 or a later model" instead of listing specific ones. * Significance: Simplification of documentation text, implies broader deprecation of the old extended thinking config format. * `build-with-claude/prompt-caching.md`: * Change 1: Added `claude-opus-5-5` to the list of models with "Dropped thinking blocks" behavior. * Change 2: PHP code snippet fix (`->value` removed from `stopReason`). * Significance: Clarifies behavior for the new Opus 5.5 model and fixes a code bug. * `build-with-claude/batch-processing.md`: * Change: Added footnotes explaining MTok, Limited access (Glasswing), and Retired models to the pricing table. * Significance: Better context for users reading the table. * `build-with-claude/context-editing.md`: * Change: CLI example code block refactoring. Instead of `cat > request.yaml`, the YAML is passed directly via heredoc. * Significance: Code improvement/UX improvement for copy-pasting examples. * `build-with-claude/working-with-messages.md`: * Change: Updated migration guide link. Old: `/models/opus-5/migration-guide#migrating-from-claude-opus-47`. New: `/models/opus-5-5/migration-guide#opus-46-breaking-changes`. * Significance: Redirects users to the correct, updated migration path for Opus 5.5. * `build-with-claude/claude-on-vertex-ai.md`: * Change: Added `claude-mythos-5-1` and `claude-mythos-5` to the Vertex AI model availability table. * Significance: Mythos models are now available on Vertex AI (limited availability). * `build-with-claude/claude-in-microsoft-foundry.md`: * Change: Added `claude-mythos-5-1` and `claude-mythos-5` to the Foundry model availability table. * Significance: Mythos models available on Foundry. * `build-with-claude/prompt-engineering/prompting-tools.md`: * Change: Removed "For details on what's new in Claude Opus 5..." link from the Tip, reorganized links slightly. * Change 2: Updated advice on "Ask Claude to self-check". Changed "When migrating to Claude Opus 5..." to "On Claude Opus 5...". (Minor phrasing). * Significance: Documentation cleanup/streamlining. * `build-with-claude/prompt-engineering/claude-prompting-best-practices.md`: * Change: Same as `prompting-tools.md`. * `agents-and-tools/tool-use/overview.md`: * Change: Reformatted the table for "Tool use system prompt token count". Split into two columns or clearer headers. Added footnotes. * Significance: Better readability, no functional change to API. * `agents-and-tools/tool-use/web-fetch-tool.md`: * Change: Added security text regarding credentials. "Claude also cannot fetch a URL that appears to contain a credential... unless that credential appears in the system prompt or in the text of a user message." * Change: Updated `url_not_allowed` error description. * Significance: **Security Enhancement**. Claude refuses to fetch URLs with credentials unless explicitly allowed by user context. 3. **Synthesize the Findings:** * **Big News:** `claude-opus-5-5` is the new headliner, appearing in API docs and migration guides. * **Availability:** `claude-mythos-5` and `5.1` are showing up on Vertex AI and Foundry (limited access). * **Betas:** New beta headers for `inline-tools` and `mcp-client` dated 2026-09-15. * **Security:** Harder restriction on web fetching URLs containing credentials. * **Cleanup:** Old migration notes (Mythos Preview) removed. Code snippets improved. 4. **Drafting the Response (in Chinese):** * **Summary:** Highlights the introduction of Claude Opus 5.5 into the API and the availability of Mythos models on other platforms, plus security updates for web fetching. * **Key Themes:** * New Model: Opus 5.5 availability and integration. * Platform Expansion: Mythos models on Vertex AI and Foundry. * Beta Features: Inline tools and MCP client headers for 2026. * Security: Credential protection in Web Fetch tool. * Doc Maintenance: Cleanup of deprecated info and code snippet improvements. * **Impact:** **Medium**. The model availability changes are significant, but mostly additive (new models). The security change in web fetch is a specific edge case but important for security. The rest is documentation polish. * **Action Items:** * Try Opus 5.5 for coding/agents. * Update migration guide references if using Opus 5. * Be aware of web fetch behavior with credentials. * Check platform availability if using Vertex AI/Foundry. 5. **Refining the Output (Self-Correction during drafting):** * *Check:* Did I miss anything? The beta headers are dated 2026-09-15. That's future-dated (relative to current real time, assuming docs are recent). This indicates planning for future capability rollouts. * *Check:* The prompt caching update for Opus 5.5. It mentions "Dropped thinking blocks" logic now applies to Opus 5.5 too. Good to note for caching strategies. * *Check:* The migration guide link change from `opus-5` to `opus-5-5`. Important for developers looking for "What's new". 6. **Final Polish (Markdown formatting):** Ensure the structure matches the request. * *Overall Summary:* 文档主要引入了 **Claude Opus 5.5** 模型，扩展了 Mythos 模型的平台支持，并针对 Web Fetch 工具增加了凭据安全保护。 * *Key Themes:* * **新模型发布**: Opus 5.5 被正式纳入 Messages API 及相关工具，定位于代码、知识工作和长时运行代理。 * **平台可用性**: Claude Mythos 5/5.1 现已在 Vertex AI 和 Microsoft Foundry 上提供（受限访问）。 * **Beta 功能预告**: 新增 `inline-tools-2026-09-15` 和 `mcp-client-2026-09-15` 两个 Beta 标头。 * **安全性增强**: Web Fetch 工具现在会拒绝获取包含凭据的 URL，除非凭据明确出现在系统提示或用户消息中。 * **文档清理**: 移除了过时的 Mythos Preview 弃用说明，更新了 PHP 代码示例和迁移指南链接。 * *Impact:* Medium. 模型更新很重要，但主要是新增选项而非强制破坏性变更（除了 Web Fetch 的安全收紧）。 * *Action Items:* * 测试 Opus 5.5。 * 检查 Web Fetch 逻辑。 * 查看 Vertex/Foundry 新模型。 * 更新迁移指南书签。 7. **Final Output Generation** (Proceed to generate text based on above).

Let me analyze the documentation changes across all 7 pages to identify the key themes, impact, and action items for developers. The changes are all related to Claude Code v2.1.280 release, introducing new features, fixing bugs, and improving documentation. Let me break it down: 1. **mcp.md**: MCP tool description truncation limit is now configurable via `CLAUDE_CODE_MAX_MCP_DESCRIPTION_LENGTH` env var (was hardcoded at 2KB, now clarified as 2,048 chars default) 2. **monitoring-usage.md**: New monitoring fields for hooks - `stdout_chars`, `additional_context_chars`, `system_message_chars`, `initial_user_message_chars`, `num_outputs_persisted` - all requiring v2.1.280 3. **plugin-marketplaces.md**: Major rewrite of background auto-updates behavior for private repos. Previously background checks disabled git credential helpers; now they USE them but run non-interactively (no prompts). This is a significant behavior change. Also removed the git URL rewrite workaround documentation since it's no longer needed. 4. **plugins.md**: New `CLAUDE_CODE_PLUGIN_DIRS` env var to load plugins without `--plugin-dir` flag 5. **skills.md**: Bug fix documentation - before v2.1.280, `manifest.json` in `~/.claude/skills/` caused personal skills to be moved to trash. Now fixed. Added troubleshooting section. 6. **slash-commands.md**: Same content as skills.md - personal skills disappeared section added 7. **vs-code.md**: Multiple new features: - `/plan` command in prompt box - `/skills` shortcut with visibility controls - `/status` command - `/sandbox` command - `/chrome` command - `/export` command - Paste text behavior (visible in prompt box, invisible Unicode removal) - Various Customize section additions Key themes: - v2.1.280 release features - Configurability/observability improvements - Bug fix documentation (skills disappearing) - Private repo auth behavior change for plugins - New VS Code commands and shortcuts