Files
deepseek-harness/packages
Tianyi Cui f58b031465 fix(agent): close the window-2 early-whenIdle race + sync cancellation RFC docs (review)
A reviewer found that window 2 (a cancel from a synchronous agent/status('running')
listener) had the same early-whenIdle() race that window 1 already guards: it
unconditionally `setStatus('idle')` + continue, which settles `whenIdle()`
waiters — so if the running listener cancels AND queues replacement work, the
waiter resolves while the replacement is still queued-and-unrun (the next
iteration runs it later, but the caller already observed quiescence).

Mirror window 1: after clearing the marker, only `setStatus('idle')` when
nothing new is queued; otherwise fall through to run the queued replacement
(status is already `running`), so `whenIdle()` resolves on that turn's
running→idle. Regression test reproduces the reviewer's interleaving (running
listener cancels A, sends B; whenIdle() resolves only after B ran).

Also syncs the cancellation contract in the two ACP RFCs that describe the live
behavior: `session/cancel` is the queue-aware `agent.cancel()` (drops an
about-to-start turn), not the old best-effort `agent.abort()` pre-step
limitation.
2026-06-20 12:57:32 +08:00
..
2026-06-19 00:37:12 +08:00

Packages

Harness packages, all under the @deepseek-ai/dsh-* scope. Each package is a Cordis plugin (microkernel-style): it exports either a default Service subclass or a functional plugin that gets registered via ctx.plugin(), declares its ctx key/events where applicable through declaration merging, and exposes extension points through ctx.effect(), ctx.on(), and ctx.waterfall().

Dependency graph

dsh-llm          (no harness deps — pure vocabulary)
dsh-bash          (no harness deps — abstract executor seam)
dsh-session       ← dsh-llm
dsh-system-prompt ← dsh-llm
dsh-agent         ← dsh-llm, dsh-session
dsh-tools         ← dsh-llm, dsh-system-prompt, dsh-agent
dsh-bash-local    ← dsh-bash                       (BashExecutor impl)
dsh-tool-bash     ← dsh-bash, dsh-tools            (bash tool schemas)
dsh-llm-deepseek  ← dsh-llm                        (DeepSeek adapter)
dsh-llm-pi-ai     ← dsh-llm                        (pi-ai-backed adapter)
dsh-agent-loop    ← dsh-llm, dsh-session, dsh-system-prompt, dsh-tools, dsh-agent
dsh-invariants    ← dsh-llm, dsh-session, dsh-agent (dev-mode contract checks)
dsh-acp           ← dsh-agent, dsh-llm, dsh-session, dsh-session-persistence  (ACP JSON-RPC bridge)
dsh-ui-stdio      ← dsh-agent, dsh-llm, dsh-session (stdio readline UI plugin)
dsh-llm-replay    ← dsh-llm, dsh-session            (record/replay adapter for keyless snapshot tests)

The rule: plugins depend on interfaces, never on the concrete loop. dsh-agent-loop is swappable — UI/hook/tool plugins keep working against the dsh-agent vocabulary if the loop is replaced. A swappable capability splits into interface / implementation / consumer packages (the bash trio is the template — see capability seams).

What goes where

Package Role ctx key
llm/ Abstract LLM service + content-block vocabulary + chunk assembler ctx.llm
session/ Event-sourced session log + in-memory store ctx.sessions
system-prompt/ Prompt-section + tool-schema assembly registry ctx.systemPrompt
tools/ Tool registry + tools/execute waterfall ctx.tools
agent/ Agent interface, registry, agent/* event vocabulary ctx.agents
agent-loop/ THE concrete loop plugin: ReactLoopAgent + the loop driver ctx.agentLoop
bash/ Abstract bash executor seam (interface + vocabulary) ctx.bash
bash-local/ Local-subprocess BashExecutor implementation (registers ctx.bash)
tool-bash/ Model-facing bash/bash_output/bash_kill tool schemas (registers on ctx.tools)
llm-deepseek/ DeepSeek API adapter (hand-rolled fetch/SSE) (registers on ctx.llm)
llm-pi-ai/ DeepSeek adapter via @earendil-works/pi-ai (design twin) (registers on ctx.llm)
invariants/ Dev-mode event-contract invariants + session-log freeze (listens on session/*, agent/*)
acp/ Agent Client Protocol bridge: serves the agent to an ACP editor over JSON-RPC stdio (drives ctx.agents/ctx.sessions)
ui-stdio/ Minimal stdio (readline) UI plugin: renders agent/* events, feeds stdin lines to the agent (drives ctx.agents)
llm-replay/ Record/replay adapter: short-circuits llm/stream with chunks from a recorded session JSONL (keyless snapshot tests) (listens on llm/stream)

Each package has its own README.md with purpose, service API, events, extension points, and deliberate non-goals (TODOs).

Conventions (applied across all harness packages)

  • Registrations are effects: every contribution (adapter, tool, section, agent, event listener) goes through ctx.effect() / ctx.on(), so disposal and HMR clean up automatically. Every register() returns the disposer.
  • Declaration merging for events and ctx: services declare their events in declare module 'cordis' { interface Events { ... } } and their ctx key in interface Context.
  • Waterfall semantics: ctx.waterfall listeners receive (...args, next) and MUST call next() to delegate; returning without it short-circuits (the veto mechanism).
  • Extensible unions: ContentBlockMap, MessageSourceMap, FinishReasonMap, TurnTriggerMap, TurnEndReasonMap, and SessionEventMap use the merge-extensible-map pattern so plugins can add variants via declaration merging.
  • ESM everywhere; imports use package names across package boundaries, .ts extensions within a package.
  • Tests: vitest, colocated under packages/<name>/tests/*.spec.ts. Every registry needs an HMR-safety test. Err on the side of more tests.