A single try/catch around ctx.emit prevented a thrown subagent/start or
subagent/end listener from propagating, but cordis emit dispatches listeners in
a `.map(cb => cb())` that HALTS on the first throw — so a bad subscriber still
starved the listeners registered after it, violating the AGENTS.md
callback-boundary rule ("one bad subscriber must not starve the listeners after
it"). Resolve the listener callbacks via ctx.events.dispatch and contain each
call individually, the same per-listener guarantee BashExecutor.notifyTaskDone
gives its own listener set.
The two containment tests now register TWO listeners where the first throws and
assert the second still observes the event (start) and the settle (end) — a
regression that fails on the per-emit code (verified: reverted, watched both go
red, restored).
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().
Hierarchy
Packages are grouped by modular role at packages/<group>/<pkg>/. The group directory is a pure container (no package.json of its own); the package name stays @deepseek-ai/dsh-<pkg> regardless of group. Each group has a README.md describing its role and whether it is product or support infrastructure.
| Group | Role | Release expectation |
|---|---|---|
core/ |
Product API spine: session, system-prompt, tools, agent, and the concrete loop | Product — stable surface |
llm/ |
LLM capability family: the abstract service + provider adapters | Product — stable surface |
bash/ |
Bash capability family: the executor seam, a local impl, and the model-facing tool | Product — stable surface |
subagent/ |
Subagent capability family: the provider-registry seam and the model-facing delegation tool | Product — stable surface |
session-persistence/ |
Persistence capability family: the seam + JSONL/SQLite backends | Product — stable surface |
ui/ |
Editor/client integration surfaces (the ACP bridge) | Product — stable surface |
support/ |
Dev/test/example infrastructure (invariants, stdio UI, replay adapter) | Support — lower compatibility expectations |
util/ |
Low-level zero-dependency utilities shared across groups (the Branded<B> primitive) |
Support — small, stable, harness-dep-free |
The split is the point: a package's group says whether it is part of the product API or support/test/example infrastructure, so release and removal decisions do not have to treat every package as an equal public contract. New packages join an existing group; adding a new top-level group is a deliberate act (extend the group READMEs and the hierarchy docs).
Dependency graph
dsh-brand (no harness deps — type-only Branded<B> primitive)
dsh-llm ← dsh-brand (vocabulary; brands CallId)
dsh-bash ← dsh-brand (abstract executor seam; brands BashTaskId/OwnerToken)
dsh-session ← dsh-llm, dsh-brand
dsh-system-prompt ← dsh-llm
dsh-agent ← dsh-llm, dsh-session, dsh-brand
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)
dsh-subagent ← dsh-agent, dsh-llm, dsh-tools (abstract subagent provider-registry seam)
dsh-subagent-mock ← dsh-subagent (scripted provider for tests)
dsh-tool-subagent ← dsh-subagent, dsh-tools, dsh-agent (model-facing delegation tool)
dsh-agent-core ← timer, dsh-llm, dsh-session, dsh-system-prompt, dsh-tools, dsh-agent, dsh-invariants, dsh-tool-bash, dsh-agent-loop (the providerless spine, as one bundle plugin)
dsh-stdio-agent ← dsh-agent-core, dsh-ui-stdio, dsh-session-persistence-jsonl, dsh-agent, dsh-session (stdio chat APP + bin)
dsh-acp-agent ← dsh-agent-core, dsh-acp, dsh-session-persistence-jsonl (ACP server APP + bin)
The rule: extension 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. The sanctioned exception is a composition/bundle package like dsh-agent-core, whose whole job is to assemble the concrete spine: it depends on dsh-agent-loop (and the other concrete spine plugins) on purpose. The rule constrains plugins that EXTEND the system, not the bundle that COMPOSES it — swapping the loop means shipping a different bundle, not rewiring every extension. A swappable capability splits into interface / implementation / consumer packages (the bash trio is the template — see capability seams).
What goes where
| Package | Group | Role | ctx key |
|---|---|---|---|
llm/ |
llm |
Abstract LLM service + content-block vocabulary + chunk assembler | ctx.llm |
session/ |
core |
Event-sourced session log + in-memory store | ctx.sessions |
system-prompt/ |
core |
Prompt-section + tool-schema assembly registry | ctx.systemPrompt |
tools/ |
core |
Tool registry + tools/execute waterfall |
ctx.tools |
agent/ |
core |
Agent interface, registry, agent/* event vocabulary |
ctx.agents |
agent-loop/ |
core |
THE concrete loop plugin: ReactLoopAgent + the loop driver |
ctx.agentLoop |
agent-core/ |
core |
Bundle plugin: the providerless/executor-less/UI-less spine as code (forwards agent-loop's agents) |
(loads the spine) |
bash/ |
bash |
Abstract bash executor seam (interface + vocabulary) | ctx.bash |
bash-local/ |
bash |
Local-subprocess BashExecutor implementation |
(registers ctx.bash) |
tool-bash/ |
bash |
Model-facing bash/bash_output/bash_kill tool schemas |
(registers on ctx.tools) |
llm-deepseek/ |
llm |
DeepSeek API adapter (hand-rolled fetch/SSE) | (registers on ctx.llm) |
llm-pi-ai/ |
llm |
DeepSeek adapter via @earendil-works/pi-ai (design twin) |
(registers on ctx.llm) |
session-persistence/ |
session-persistence |
Persistence seam + write coordinator | ctx.sessionPersistence |
session-persistence-jsonl/ |
session-persistence |
JSONL-sidecar persistence backend | (registers ctx.sessionPersistence) |
session-persistence-sqlite/ |
session-persistence |
SQLite persistence backend | (registers ctx.sessionPersistence) |
invariants/ |
support |
Dev-mode event-contract invariants + session-log freeze | (listens on session/*, agent/*) |
acp/ |
ui |
Agent Client Protocol bridge: serves the agent to an ACP editor over JSON-RPC stdio | (drives ctx.agents/ctx.sessions) |
stdio-agent/ |
ui |
Terminal stdio chat APP: agent-core spine + console logger + readline UI + a pre-created main agent, with a bin |
(composition + bin) |
acp-agent/ |
ui |
ACP server APP: agent-core spine + JSONL persistence + the acp bridge (no stdout logger), with a bin |
(composition + bin) |
ui-stdio/ |
support |
Minimal stdio (readline) UI plugin: renders agent/* events, feeds stdin lines to the agent |
(drives ctx.agents) |
llm-replay/ |
support |
Record/replay adapter: short-circuits llm/stream with chunks from a recorded session JSONL (keyless snapshot tests) |
(listens on llm/stream) |
subagent/ |
subagent |
Abstract subagent seam: named-provider registry for delegating to child agents | ctx.subagents |
subagent-mock/ |
support |
Scripted SubagentProvider for testing the seam through the real load path |
(registers on ctx.subagents) |
tool-subagent/ |
subagent |
Model-facing subagent delegation tool over ctx.subagents |
(registers on ctx.tools) |
brand/ |
util |
Type-only Branded<B> nominal-typing primitive (no runtime code, no harness deps) |
(none — type-only) |
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/<group>/<pkg>/tests/*.spec.ts. Every registry needs an HMR-safety test. Err on the side of more tests.