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()`.
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/`](core/README.md) | Product API spine: session, system-prompt, tools, agent, and the concrete loop | Product — stable surface |
| [`llm/`](llm/README.md) | LLM capability family: the abstract service + provider adapters | Product — stable surface |
| [`bash/`](bash/README.md) | Bash capability family: the executor seam, a local impl, and the model-facing tool | Product — stable surface |
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).
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](../docs/rfc/implemented/architecture/2026-06-13-capability-seams.md)).
| `llm-replay/` | `support` | Record/replay adapter: short-circuits `llm/stream` with chunks from a recorded session JSONL (keyless snapshot tests) | (listens on `llm/stream`) |
- **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.
