deepseek-harness/packages/README.md

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
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

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-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)
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: 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	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)

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/<group>/<pkg>/tests/*.spec.ts. Every registry needs an HMR-safety test. Err on the side of more tests.