Codex + an independent review pass found three real defects in the prior commit: 1. parseExitStatus could misreport a SUCCESSFUL command as a failure: a clean exit 0 appends no marker, so output ending in "[exit code: 5]" (no trailing newline) was read as the marker. Anchor the parse to a LEADING newline — renderResult always inserts one before a real marker, so a body that merely ends in marker-like text no longer matches. A narrow residual (a clean exit 0 whose final line is exactly the marker) is inherent to the replay-only-sees- text design and documented; the complete fix (a structured exit on the event) is the RFC's named escape hatch. 2. A run_in_background start and an isError result were rendered as exited terminal cards with a false exit-0 pill. A background start returns a task-id ack (not a streamed terminal) and is no longer marked terminal; an isError result (spawn failure / abort) carries no exit pill. 3. The terminal capability was re-read live on the result path, so a second initialize between a call and its result could desync them (orphan terminal_output or clobbered card). Snapshot the capability per session at creation (SessionRecord.terminalEnabled) so call and result always agree. Also reword the reference-parity claim: keeping the description as a content block in terminal mode is a DELIBERATE divergence (claude-agent-acp drops it). Tests added for each; with-key e2e still green.
Packages
Harness packages, all under the @deepseek-ai/dsh-* scope. Each package is a Cordis service (microkernel plugin-style): it exports a default Service class that gets registered via ctx.plugin(), declares its ctx key and events 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)
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 plugin: LoopAgent + 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) |
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. Everyregister()returns the disposer. - Declaration merging for events and ctx: services declare their events in
declare module 'cordis' { interface Events { ... } }and their ctx key ininterface Context. - Waterfall semantics:
ctx.waterfalllisteners receive(...args, next)and MUST callnext()to delegate; returning without it short-circuits (the veto mechanism). - Extensible unions:
ContentBlockMap,MessageSourceMap,FinishReasonMap,TurnTriggerMap,TurnEndReasonMap, andSessionEventMapuse the merge-extensible-map pattern so plugins can add variants via declaration merging. - ESM everywhere; imports use package names across package boundaries,
.tsextensions 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.