Files
deepseek-harness/docs/tool-execution-pipeline.md
T
kingwl ef35007d75 feat(approval): the approval seam — one-shot permission decisions over a waterfall of answerers
ctx.approval (dsh-approval): request() dispatches the approval/request
waterfall and always resolves a closed outcome — allowed-once / rejected /
cancelled / unavailable — never rejects; zero listeners fall through to
fail-closed unavailable; abort settles cancelled and discards late answers;
throwing or rogue answerers are contained as unavailable; every ask lands
the log-only approval/asked / approval/decided audit pair. dsh-tools routes
a pre-execute ask through the seam opportunistically (ctx.get) with three
distinct deny reasons, keeping the historical ask→deny degrade when the
seam is absent.

The per-session policy tier, the ACP bridge answerer, and the sandbox
escalation asker are staged follow-ups of the approval-seam RFC.
2026-07-10 15:43:02 +08:00

2.5 KiB

Tool Execution Pipeline

This graph shows where policy, hooks, sandboxing, filesystem guards, result rewriting, and UI rendering fit without changing the loop. The key extension points are the tools/pre-execute, tools/execute, and tools/post-execute waterfalls.

flowchart TD
  model["Assistant message contains tool-call block"]
  toolCall["Session event: <code>tool/call</code><br/>logged before execution"]
  presentCall["UI pending card<br/>presentCall(args)"]
  pre["<code>tools/pre-execute</code> waterfall<br/>hooks, permission, sandbox"]
  denied["denied<br/>tool body skipped"]
  approval["<code>ctx.approval</code> one-shot prompt<br/>absent or unanswerable: deny"]
  around["<code>tools/execute</code> waterfall<br/>timeout, retry, metrics (around dispatch)"]
  toolBody["Registered tool execute() body"]
  fsGate["<code>fs/write-intent</code> or <code>fs/edit-intent</code><br/>tool-fs mutations only"]
  owned["Tool-owned session events<br/><code>todo/write</code>, <code>fs/observed</code>, <code>hook/invoked</code>, <code>hook/result</code>, <code>tool/code-dispatch</code>"]
  post["<code>tools/post-execute</code> waterfall<br/>accept, block, replace, add context"]
  context["Buffered additionalContext<br/>context/message after all tool results"]
  toolResult["Session event: <code>tool/result</code><br/>single model-facing outcome"]
  presentResult["UI completed card<br/>presentResult(args, result)"]
  model --> toolCall
  toolCall --> presentCall
  toolCall --> pre
  pre -->|allow| around
  around --> toolBody
  pre -->|deny| denied
  pre -->|ask| approval
  approval -->|allowed-once| around
  approval -->|rejected, cancelled, unavailable| denied
  denied --> post
  toolBody --> fsGate
  fsGate --> toolBody
  toolBody --> owned
  toolBody --> around
  around --> post
  post --> context
  post --> toolResult
  toolResult --> presentResult

Filesystem read-before-edit checks live below tool-fs on the fs/* event gate; hook bridges and the approval seam's permission prompts live on the generic pre/post tool waterfalls; and around-dispatch concerns like the tool-call timeout policy (@deepseek-ai/dsh-timeout-policy) wrap core dispatch on tools/execute. That split lets the same hooks observe bash, fs, web, todo, and subagent calls without coupling those tools to one policy service.

Maintenance mode: curated Mermaid flow; exact tool schemas and event signatures live in generated catalogs.