Files
deepseek-harness/packages
Tianyi Cui 2be60b9a22 simplify(session): fold trace-only usage/error events into load-bearing events
The session event vocabulary carried two standalone trace-only events that
were not load-bearing as separate records. Fold their facts into nearby
load-bearing events and delete the standalone variants.

- Token usage now rides on `assistant/message` as an optional `usage` field —
  the assembled model output and its accounting travel together. The loop folds
  `assembler.usage` onto the append instead of emitting a separate `usage`
  event.
- The max-tokens path is the no-data-loss host: a step cut off with usage but
  EMPTY content (e.g. only a dropped tool call) previously emitted a standalone
  `usage`; it now records an empty-content `assistant/message { content: [],
  usage }`. `deriveMessages()` skips empty-content assistant messages, so the
  usage host never injects a spurious content-less assistant turn into the
  provider transcript. A step with neither content nor usage appends nothing.
- An operational error's step number now rides on `turn/end.reason` for
  `kind: 'error'` (`{ kind: 'error', step, message, code? }`) — the durable
  turn outcome ACP and resume already consume. `failTurn` sets the reason
  directly (no separate session `error` event). `agent/error` + logging are
  unchanged for live diagnostics.
- No format-version bump: pre-release, no persisted data, so per the format
  policy there is nothing to migrate or reject (the RFC's "refresh the format
  version" criterion over-reached). `version` stays 1.
- ACP fixtures + goldens re-recorded (keyless replay): dropped standalone
  usage/error lines, usage folded onto assistant/message, error step on
  turn/end.reason.

RFC moved proposed -> implemented with an implementation note recording the two
scope refinements.
2026-06-21 10:00:06 +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().

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)

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
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)
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.