# 工具执行流水线 [English](tool-execution-pipeline.md) | 中文 此图展示了策略、钩子、沙箱、文件系统守卫、结果重写、最终结果观察和 UI 渲染如何在不改变循环的前提下各就其位。可转换的扩展点是 `tools/pre-execute`、`tools/execute` 和 `tools/post-execute` waterfall（瀑布式事件）；围绕这些扩展点的边界则由所有者强制执行，包括单调守卫、由定义自身控制的 `finalizeContent`，以及 `tools/result`。 ```mermaid flowchart TD model["Assistant message contains tool-call block"] toolCall["Session event: tool/call
logged before execution"] presentCall["UI pending card
presentCall(args)"] pre["tools/pre-execute waterfall
hooks, permission, sandbox"] guards["Registered monotonic guards
deny or abstain; identity protected"] denied["denied or approval refused
tool body skipped"] approval["ctx.approval one-shot prompt
absent or unanswerable: deny"] around["tools/execute waterfall
timeout, retry, metrics (around dispatch)"] toolBody["Registered tool execute() body"] fsGate["fs/write-intent or fs/edit-intent
tool-fs mutations only"] owned["Tool-owned session events
todo/write, fs/observed, hook/invoked, hook/result, tool/code-dispatch"] post["tools/post-execute waterfall
accept, block, replace, add context"] normalized["Registry outer normalization
pipeline/result snapshot throws become isError"] finalize["ToolDefinition.finalizeContent
last content-only invariant"] final["tools/result synchronous notification
frozen authoritative outcome"] context["Active-batch additionalContexts FIFO
injected user/message after recorded tool results"] toolResult["Session event: tool/result
single model-facing outcome"] allResults["Tool batch settled
recorded tool/result events complete"] presentResult["UI completed card
presentResult(args, result)"] model --> toolCall toolCall --> presentCall toolCall --> pre pre -->|allow| guards guards -->|allow| around guards -->|deny| denied guards -.->|throw| normalized around --> toolBody pre -->|deny| denied pre -->|ask| approval approval -->|allowed-once| guards approval -->|rejected, cancelled, unavailable| denied approval -.->|throw| normalized denied --> post pre -.->|throw| normalized toolBody --> fsGate fsGate --> toolBody toolBody --> owned toolBody --> around around --> post around -.->|wrapper throws| normalized post -.->|throw| normalized post --> finalize normalized --> finalize finalize --> final final --> toolResult toolResult --> presentResult toolResult --> allResults allResults --> context ``` 文件系统的先读后编辑检查位于 `tool-fs` 之下，通过 `fs/*` 事件实现。通用的前置／后置 waterfall 承载钩子与审批策略；`ctx.approval` 在单调守卫之前处理询问，而不得重新排序的所有者策略仍作为已注册的守卫。超时等环绕分发关注点对 `tools/execute` 进行包装。注册表会对候选结果进行无损快照；如果快照失败，则会先将失败规范化，之后再由可见定义中已随快照固定的 `finalizeContent` 回调强制执行其同步且仅限内容的不变式。随后，`tools/result` 会观察不可变、可由 JSON 无损表示的结果。这样一来，钩子便可跨越不同工具系列，而无需让工具与某个策略服务耦合。Code Mode 会将保留的 `run_code` 传输及其序列化子调用都送入流水线；子调用携带父级 token、记录 `tool/code-dispatch`、将拒绝呈现为具有约束力的驳回，并省略 `additionalContexts`，以保持调用与结果相邻。 维护模式：英文源文件包含人工维护的 Mermaid 流程图，并由生成器写出；本中文文件作为经评审对侧通过双语配对维护。确切的工具 schema 与事件签名位于生成的目录中。