# @deepseek-ai/dsh-client-ui-model

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Model selection plugin, browser half: TWO entries over ONE per-session directory owned by `ModelService` (`ctx.models`). For ordinary sessions, the `/model` popupSelect contribution (registered through `ctx.command`) and the composer's named `conversation.input.model` seat both load the session's advisory directory through `session.models` and submit through `session.selectModel` via the same `ModelDirectory` instance. The compact composer trigger opens a two-level Model/Effort menu: models stay provider-grouped, while the selected exact model supplies its adapter-owned effort names, descriptions, and default. `/model` applies the selected model's default effort, and the composer can then choose any advertised effort.

The Host-reported provider/model/reasoning target is the single selection fact, but it is echoed only when the exact route remains in the advertised groups; removing that catalog row leaves the routable target intact while the trigger prompts `Select model`, no stale row is synthesized, and no Effort row is shown until the user picks an advertised model. Directory loads and selections share a generation counter so an older response never overwrites a newer one; a connection reset drops every resident projection and repulls the Host-restored target before display. Provider-local metadata failures list inline while usable groups stay selectable, and selection failures retain the prior target and directory.

When the Host reports that no adapter serves the session's route (`session.models.routable`), this plugin raises a composer block through `ctx.conversation.blocks` and the input goes inert with this plugin's own copy; recovering clears it without a reload. It follows `routable` and nothing else: a `null` — before the first load, or after one failed — never blocks, or a slow Host would lock a working composer, and catalog membership never blocks either, because a route serving a model it stopped advertising is missing from the groups yet perfectly usable. The trigger's own `Select model` fallback still covers that case, which is display, not a gate.

Directories are per-session, resolved lazily through `ctx.models.directoryFor(sessionId)`, and disposed with the session scope. Addressed subagent sessions expose neither entry, and their directory rejects loads, selections, and reconnect refreshes, because ordinary Agent-bound model RPCs would activate persisted child history outside the direct-parent continuation seam.

The `/client` export surface is the plugin body (`apply`/`inject`), `ModelService`, `ModelDirectory` with its state shape, and the seat's injected face type.

## Model Experience

Indirectly, through the `session.selectModel` RPC available to ordinary sessions, both entries submit the provider/model/reasoning target that the Host snapshots at the next prompt-assembly boundary, so the following request uses the chosen route and effort while a running step keeps its assembled target; the selection becomes durable only when the existing request header records a request that consumes it, and menu interaction adds no prompt content.

#### KV Cache effect

Switching the route can reduce or invalidate provider-side cache reuse for subsequent requests; the prompt prefix itself is untouched.

## Known Limitations and Deferred Work

- **No create-time or addressed-subagent selection** — both entries require an existing ordinary session's Agent; there is no draft-phase model choice to fold into session creation, and subagent continuation deliberately exposes no independent model-retargeting contract.
- **Directory names are presentation-only** — selection and persistence use provider/model/effort ids; a provider whose catalog or exact-model metadata lookup fails lists as an unselectable failure row until reload.
- **No arbitrary effort input** — the composer offers only the exact model's adapter-advertised levels; an adapter without reasoning metadata leaves the Effort row absent.
