Harness packages use the `@deepseek-ai/dsh-*` scope. Each is a Cordis plugin: a default `Service` subclass or functional plugin declaring ctx keys/events through declaration merging and contributing through `ctx.effect()`, `ctx.on()`, or `ctx.waterfall()`. Authoring conventions: [AGENTS.md](AGENTS.md) and root [AGENTS.md](../AGENTS.md) § Conventions.
Packages are grouped by modular role at `packages/<group>/<pkg>/`. The group directory is a pure container (no `package.json`); the package name stays `@deepseek-ai/dsh-<pkg>` regardless of group. **Each group README is the canonical per-package map** — package roles, ctx keys, and the product-vs-support split live there, next to the code.
| [`web/`](web/README.md) | Web capability family: the abstract seam, search/fetch provider impls, and the model-facing web tools | Product — stable surface |
| [`util/`](util/README.md) | 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 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 this table).
The rule it must obey: **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. 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)).
Package READMEs cover purpose, APIs, extension points, and [Model Experience](../docs/cookbook/adding-a-package.md#4-write-the-package-readme) unless on the model-agnostic [omission allowlist](../scripts/verify-package-readme-model-experience.ts). They also carry `## Known Limitations and Deferred Work` or use its [allowlist](../scripts/verify-package-readme-limitations.ts).