# 文档变更分析
## 总体概述
本次文档更新引入了针对 Web 工具（Web Fetch/Web Search）的细粒度安全控制参数 `url_sources`，允许开发者精确控制模型的 URL 获取来源。同时，新增了 `compact-2026-09-04` 能力标志，并修正了 Go SDK 中多个方法的调用签名，要求传入额外的参数结构体。
## 核心变更主题
* **Web 工具安全增强 (`url_sources`)**
在 `api/messages.md` 及相关文件中，为 `WebFetchTool` 和 `WebSearchTool` 新增了 `url_sources` 参数。该参数允许开发者通过 `all`、`none`、`only`、`except` 等选项，严格控制 Web Fetch 可以抓取的 URL 来源（例如：仅允许用户输入的 URL，或仅允许特定工具返回的 URL）。这显著增强了基于 Agent 的应用的安全性。
* **Go SDK API 签名变更**
在 `build-with-claude/batch-processing.md`、`files.md` 等页面中的 Go 代码示例已更新。方法调用（如 `Batches.Get`、`Files.GetMetadata`、`Files.Download` 等）现在**必须**在末尾传入一个空的参数结构体（例如 `anthropic.MessageBatchGetParams{}`）。这表明 SDK 进行了破坏性更新，不再支持省略可选参数。
* **新增能力标志**
在 `api/models/list.md` 中，能力列表从 42 个增加到 43 个，新增了 `"compact-2026-09-04"` 标志。虽然具体细节尚未完全披露，但这通常预示着某种新的模型功能或优化模式即将推出。
* **文档与链接规范化**
更新了 API 密钥相关的文档链接（统一指向 `/docs/en/get-api-key`），并修正了定价表格中上标标记的 Markdown 格式，提升了文档的一致性和可读性。
## 影响等级: **中等至高**
**理由:**
1. **功能增强（高影响）**：`url_sources` 参数为使用 Web 搜索和抓取工具的开发者提供了关键的安全控制能力，防止模型在未经授权的情况下访问内部工具生成的敏感 URL。
2. **代码破坏性变更（高影响）**：Go SDK 的方法签名变更是破坏性的，使用该语言的开发者必须修改现有代码以适配新的参数结构。
3. **新特性预告（中等影响）**：`compact-2026-09-04` 的出现暗示了平台能力的扩展，需要开发者密切关注后续说明。
## 开发者行动项
* **更新 Go SDK 代码**：检查所有调用 `client.Messages.Batches.*` 或 `client.Files.*` 的代码，务必在方法调用中添加相应的空参数结构体（例如 `Params{}`），以避免运行时错误。
* **实施 URL 来源控制**：如果您正在使用 Web Search 或 Web Fetch 工具，请评估并配置 `url_sources` 参数，以限制模型仅从可信来源（如仅限用户输入）抓取内容，从而提升应用安全性。
* **关注 `compact-2026-09-04`**：留意关于该新能力标志的官方公告或文档更新，判断是否适用于您的使用场景。
💭 Model Reasoning
1. **Analyze the Request:**
* **Role:** World-class programmer/developer tools expert.
* **Task:** Analyze documentation changes (13 pages total).
* **Format:** Concise, insightful analysis in Markdown.
* **Language:** Chinese.
* **Key Outputs:** Overall Summary, Key Themes, Impact Level (with reasoning), Action Items.
2. **Scan and Process Each Page's Diff:**
* `get-started.md`:
* Change: Link update for API key (`/settings/keys` -> `/docs/en/get-api-key`).
* Impact: Minor, documentation polish/navigation improvement.
* `about-claude/pricing.md` & `build-with-claude/prompt-caching.md`:
* Change: Markdown formatting for superscript footnotes (`MTok1` -> `MTok<sup>1</sup>`) and aligning tables. Also a specific pricing note update.
* Impact: Formatting standardization. No pricing logic change (just presentation).
* `api/overview.md` & `api/errors.md`:
* Change: Link updates related to API keys (pointing to `get-api-key`).
* Impact: Consistent documentation structure.
* `api/models/list.md` & `api/beta/files/upload.md`:
* Change: Updated "capabilities" header count ("42 more" -> "43 more").
* Specific addition: `"compact-2026-09-04"`.
* Impact: New capability flag `compact-2026-09-04` added to the API. This likely enables a new feature or optimization mode.
* `api/messages.md`, `api/messages/count_tokens.md`, `api/messages/batches/create.md`:
* Change: Massive addition of a new parameter `url_sources` to various web fetch/search tools (`WebFetchTool20250219`, `WebSearchTool20260209`, `WebFetchTool20260309`, etc.).
* Structure: `url_sources` contains `client_tool_results`, `server_tool_results`, and `user_input`. It allows granular control (`all`, `none`, `only`, `except`) over where URLs can be fetched from.
* Impact: **High**. This introduces a significant security/flexibility feature for controlling how Web Fetch and Web Search tools interact with URLs derived from user input versus tool results. It adds fine-grained control over the "web surfing" behavior of agents.
* `build-with-claude/batch-processing.md`, `build-with-claude/files.md`, `agents-and-tools/tool-use/code-execution-tool.md`:
* Change: Go SDK code updates.
* Pattern: Adding empty params objects to methods (e.g., `client.Messages.Batches.Get(..., anthropic.MessageBatchGetParams{})`, `client.Files.GetMetadata(..., anthropic.FileGetMetadataParams{})`).
* Impact: API breaking change in the Go SDK (or at least a required syntax update). The method signatures likely changed to require an options struct even if empty.
3. **Synthesize and Structure the Analysis (in Chinese):**
* **Overall Summary:** Documentation updates focus on a new security control mechanism for web tools (`url_sources`), the introduction of a new capability flag (`compact-2026-09-04`), and necessary updates to the Go SDK examples regarding method signatures.
* **Key Themes:**
* **Web Tool Control:** Introduction of `url_sources` parameter to restrict where Web Fetch/Web Search gets URLs (user input vs. tool results). This is a big deal for agent security.
* **New Capability:** Addition of `compact-2026-09-04` capability header.
* **Go SDK Updates:** Function calls now require an options struct (e.g., `Params{}`).
* **Doc Polish:** Link updates and formatting fixes.
* **Impact Level:**
* Level: **Medium to High**.
* Reasoning: The `url_sources` feature represents a significant functional enhancement for web-enabled agents, providing much-needed control over URL fetching scope. The changes to the Go SDK examples suggest a change in the client library signature that will affect developers using Go. The pricing changes are cosmetic.
* **Action Items:**
* Review `url_sources` parameter if you use Web Search/Fetch tools to implement URL source restrictions.
* Update Go SDK code to include the new empty parameter structs (e.g., `FileGetMetadataParams{}`) in method calls.
* Check for the `compact-2026-09-04` capability if relevant to your specific use case (though details are sparse, it's a new flag to watch).
4. **Drafting the Content (Iterative refinement for conciseness):**
* *Drafting Summary:* 本次文档更新引入了针对 Web 工具的细粒度控制参数 `url_sources`，用于限制 URL 获取来源。此外，新增了 `compact-2026-09-04` 能力标志，并修正了 Go SDK 中方法的调用签名。
* *Drafting Themes:* 细粒度的 URL 来源控制（`url_sources`），新增能力标志，Go SDK 方法签名变更（需要传入 Params 结构体），文档链接规范化。
* *Drafting Impact:* High/Medium. `url_sources` is high for security/control. Go SDK changes are medium impact for existing code.
* *Drafting Action Items:* Update Go code. Implement `url_sources` for safer web browsing. Monitor `compact-2026-09-04`.
5. **Final Polish (Markdown formatting):** Ensure the tone is professional and "world-class".
* *Self-Correction on Go SDK:* The diffs show `client.Messages.Batches.Get(..., anthropic.MessageBatchGetParams{})`. This implies the previous signature `Get(ctx, id)` is now `Get(ctx, id, params)`. This is a breaking change for Go users who need to update their code. I must emphasize this.
6. **Final Output Generation (matching the requested structure):**
(See the final output below)