deepseek-harness/.agents/notes/implemented/architecture/2026-07-30-web-config-plane.md

# Agent Note: the web configuration plane

Status: implemented

English | [中文](2026-07-30-web-config-plane.zh.md)

> Scope: the wire face and web UI deferred from the [request-level LLM configuration note](2026-07-29-request-level-llm-config-credentials.md) — the `settings.*`/`credentials.*`/`llm.*` RPC domains with pushed invalidations, layered+redacted `describe()`, the llm configurable-provider directory and topology event, the standalone `dsh-client-schema-form` model layer, and the Models settings page with its hand-written provider editor. The `deepseek` → `deepseek-official` provider-route rename rides along as the enabling breaking change.

## Problem

PR1 made LLM adapter configuration restart-free at the seam, but the only writer was a text editor on `settings.yaml`: the web client had no wire access to settings, credentials, or provider topology, so "store a key, prompt again" still meant leaving the product. Three gaps blocked a config page rather than one: `describe()` returned only the merged effective value (a form cannot tell a user override from a composition default, and serializing it would have shipped `role('secret')` values to every browser), nothing enumerated the providers an adapter *could* run (a bare-mounted `llm-pi-ai` was invisible until configured), and the two adapters both wanted a `deepseek` route key, so the directory could not attribute routes to owning namespaces unambiguously. Hand-maintaining a form per provider was rejected outright — the schemas already exist as schemastery `Config` values, and a second source of field truth drifts.

## Decision

**Wire domains on the compiled RPC map, rejections as codes, invalidations as frames.** `settings.describe/update/replace`, `credentials.describe/set/unset`, `llm.providers`, and `llm.models` (claiming the reserved `host.listModels` surface) join `RpcMethodMap`, so the seven compiler-locked wiring sites keep contract, schema, handler, and client in lockstep. Seam rejections fold into `settings-rejected {ns}` / `credential-rejected {ref}` business errors (HTTP stays a carrier), and three `HostFrame`s — `host/settings-changed {ns}`, `host/credentials-changed {ref}`, `host/models-changed` — follow the `host/commands-changed` shape so every client converges without polling. Writes join `pickDirectory`/`openPath` in the connection guard's privileged set: loopback + same-origin or 403, because a LAN-exposed dsh web must not accept config mutation from another origin.

**`describe()` grows layers and structural secret redaction.** `SettingsDescriptor` carries `base`/`user` beside the effective value, so the form marks "overridden" by presence in the user layer, not value inequality (an override *equal* to the base is still an override). `describe({ redactSecrets: true })` — mandatory at every wire face — strips `role('secret')` subtrees from all three layers via a pure structural walk of the schema (object/dict/array containers; a secret-role subtree is one opaque leaf) and enumerates the stripped slots as `{path, set}`, so a page can render write-only inputs without ever receiving a value.

**The llm seam declares configurability and announces topology.** `registerConfigurableProviders()` is an all-or-nothing, fiber-scoped directory of `{provider, displayName, settingsNs, settingsPath}` — the addressing a config page needs to open the right settings subtree for a route that may not exist yet; `listConfigurableProviders()` merges with live routes in the wire handler so undeclared live routes still report active. The zero-payload `'llm/adapters-updated'` event fires from all four registration/unregistration commit points with contained listener dispatch (INVARIANT rethrow), following the settings/commands precedent. `llm-deepseek`'s route renamed to `deepseek-official` because the pi-ai catalog legitimately owns `deepseek` as an aggregator entry; pre-release stance, no alias.

**A hand-written editor over a schema model layer.** `dsh-client-schema-form` rehydrates the wire's `toJSON()` envelope into live schemastery nodes for validation, path resolution, and immutable draft editing — but no generic rendering: the first cut shipped a full schema-driven form renderer, and the resulting page was an unstyled schema dump (every advanced field flattened onto the card, raw field names as labels, the `retryPolicy` unsupported-fallback in the main flow). The user chose the hand-written direction over adding a hint/grouping system, and a second round removed the reference input entirely: the card's primary field is one **API key** input, a whole-section provider without a configured key opens as its setup card, and the collapsed 自定义设置 fold carries the curated per-family extras (`baseURL` for both families, plus `reasoningEffort` for deepseek / `reasoning` for pi-ai), with every other field owned by `settings.yaml`. Validation still runs the rehydrated schema before writing, so a hand-coded field that drifts from its schema fails loud on save rather than silently.

**The Models page is a three-domain join with seam-shaped apply semantics.** Rows are configured providers; the add card's select is the dormant directory remainder; badges come from route liveness. The key path stays reference-shaped without ever showing a reference: a typed key stores **write-only** through `credentials.set` under the profile's `apiKeyEnv`, deriving `<ROUTE>_API_KEY` when none exists (the pi-ai profile records the derivation), so `settings.yaml` never carries a key value and the wholesale `settings.replace` a removal needs can never drop a sibling's secret. An edit without removals lands as a minimal `settings.update` merge patch; clearing a fold field back to inherited or deleting a row replaces the whole user section, because merge semantics cannot express removal.

## Alternatives considered

- **Serving JSON Schema over the wire** — schemastery's `toJSON()` envelope round-trips `role()`/meta and rehydrates into the validator the client already ships for drafts; converting to JSON Schema loses exactly the role annotations the credential control and secret redaction key on.
- **A generic schema-driven form renderer** — implemented first, then replaced: field truth without visual hierarchy produced an ugly, unusable card, and making it good meant building a hint vocabulary (primary/advanced grouping, per-field descriptions, array item cards) rivaling the hand-written editor in cost while still fitting no mockup exactly. Two schemas exist today (the deepseek `Config` and the shared pi-ai profile), so hand-writing is two thin namespace-keyed layouts; the drift risk is bounded by save-time schema validation and by unknown fields staying untouched in the document.
- **Masking secrets per-field with sentinel backfill on `replace`** — the PR1 decision (secrets are references) already deleted the stored-literal case for the product default; structural redaction plus a write-only credential path handles the residue without teaching every writer a sentinel protocol.
- **Storing the typed key as a literal `apiKey` setting** — the v1 "one API key input" requirement could have written the literal into the profile, but every UI removal path rebuilds the user section from the *redacted* layers, so any reset or row deletion would silently drop stored sibling keys; deriving a reference keeps the input single-field while keeping `settings.yaml` secret-free and every replace safe.
- **A `models` bridge plugin owning provider configuration** — same rejection as PR1: per-plugin namespaces plus a four-field directory declaration give the UI everything it needs; the bridge's unified dict re-imports the adapter-mapping indirection.
- **Page-side polling instead of pushed frames** — the mux already carries `host/commands-changed`; three more frames cost one shape each and make a second tab, an external `settings.yaml` edit, and a settings-born route converge at event speed.

## Consequences

The whole loop is pinned keyless in the browser lane (`apps/web/tests/models-settings.e2e.ts`): the add card offers the dormant pi-ai catalog, adding `minimax-cn` with a typed key writes the reference-only profile into `settings.yaml`, stores the value into the harness home's `.env` under the derived `MINIMAX_CN_API_KEY`, registers the route live on the topology frame, and the customized fold merges `reasoning` beside the reference — zero model calls, ARIA goldens for the add-card and configured states, plus a scaffold `harnessHome` so tests never touch a real `~/.dsh` (the provider under test is one whose derived reference cannot collide with a developer's exported keys). The rename touched 239 files (fixtures, goldens, docs, python) in one commit with no compatibility alias. The renderer replacement cost one commit and no wire change: apply semantics, redaction, and the directory join were renderer-agnostic all along. Deferred: a per-row models preview (the picker already lists models), a page address for live routes that never declared configurability, and the documented reset edge — a `settings.replace` cannot re-supply a stored *literal* secret in the replaced subtree, which the reference-based default makes unreachable.