feat(ui): make a session that cannot send refuse to accept one

A default naming a route the Models page has since removed left the
composer saying 选择模型 while the input still accepted a message, which
then failed inside the adapter mid-turn.

`session.prompt` now refuses with `model-unavailable` before opening a
turn. That is the enforcement boundary: the method stays callable no
matter what a client disables. `session.models` reports the same fact as
`routable`, and ui-model pushes a block through the new
`ctx.conversation.blocks` registry so the bar renders the disabled
textarea it already renders without a workspace, carrying the blocker's
own reason. The push direction is forced — ui-model already depends on
ui-conversation, so ui-conversation cannot read it back.

The gate is `routable`, not "matches no advertised group": catalog
membership is advisory, so a route serving a model it stopped advertising
is missing from the groups yet perfectly usable, and `null` before the
first load never blocks so a slow Host cannot lock a working composer.

The scaffold gains a route-only adapter for fixture-less keyless
scenarios. Registering zero providers is a test artifact — every product
composition mounts one — and the goldens that froze the seat's fallback
label now show the model those scenarios actually route to.

packages/client/connection/src/client/fixture.ts

@@ -1975,6 +1975,9 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
       models: request => ok(request, {
         current: modelTargets.get(request.payload.sessionId)
           ?? { provider: 'deepseek-official', model: 'deepseek-v4-flash' },
+        // The fixture's routes all serve; a surface exercising the blocked
+        // posture drives it through its own stub.
+        routable: true,
         groups: fixtureModelGroups(),
         failures: [],
       }),

packages/client/connection/tests/fake-api.ts

@@ -59,6 +59,7 @@ export class FakeApiClient implements IApiClient {
 
   onModels: (payload: unknown) => Promise<RpcResponse<SessionModels>> = () => Promise.resolve(ok({
     current: { provider: 'deepseek-official', model: 'deepseek-chat' },
+    routable: true,
     groups: [],
     failures: [],
   }))

packages/client/runtime/tests/fake-api.ts

@@ -73,6 +73,7 @@ export class FakeApiClient implements IApiClient {
 
   onModels: (payload: unknown) => Promise<RpcResponse<SessionModels>> = () => Promise.resolve(ok({
     current: this.defaultModel,
+    routable: true,
     groups: [{
       id: 'deepseek-official',
       name: 'DeepSeek',

packages/client/ui-conversation/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-conversation/README.md
-README.md: a75f25d8669cd688795842a655106e0e27bb7173
-README.zh.md: f0d744c31020730857d210d75749b907dbffca08
+README.md: 392f9956b33df88a5e9664a58de27d85fc0457d1
+README.zh.md: 6b0429a302475f84a7ce9b1cdc9fd47d90d6dba3

packages/client/ui-conversation/README.md

@@ -8,6 +8,8 @@ Compaction renders as one collapsed row at the checkpoint's flow position withou
 
 The resident conversation shell survives no-session and session transitions. Without a current session it renders a disabled input bar; its root-scoped `conversation.hero.workspace` slot hosts the Workspace picker. Selecting a Workspace connects or reuses its Host-owned blank session and opens that session without replacing the shell. The root always owns the same scrollport and Hero/composer subtree; separate strict-session header and body outlets fill their regions when the first Session arrives, so the Workspace picker, scroll body, composer seat, and textarea retain their React and DOM identity. Blank sessions render the same composer body as active sessions, while the InputHub carries drafts across Workspace switches and mirrors them into the session store. In the active phase the session header shows only the current session title and view tabs as ordinary column chrome; fork lineage remains session data and is not projected into the header. Beneath it the scrollport (`data-conversation-scroll`) holds the flowing views and the sticky composer stack (stats dock + input docks + bar). That scrollport reserves its scrollbar gutter unconditionally, and a view opting into a composer overlay leaves it a scroll container, so the input card keeps one horizontal position whether or not the transcript scrolls and whichever view tab is shown ([decision](../../../.agents/notes/implemented/bug-fix/2026-08-04-composer-tab-gutter-reservation.md)). Wheel over the textarea chains: the capped draft scrolls locally until its edge, then forwards to that host.
 
+Another plugin can make one session's composer inert through `ctx.conversation.blocks`: it sets a block carrying its own localized reason, and the bar renders the same disabled textarea with that reason as the placeholder — the no-workspace posture, reused. The push direction is the constraint, not a preference: the plugins that know a session cannot send (ui-model, when no adapter serves its route) already depend on this package, so this package cannot read them. A block is an affordance only; the Host refuses a prompt it cannot route regardless of what any client disables. The no-workspace state wins when both hold, because picking a workspace is the earlier prerequisite.
+
 The view ring is a slot: the strict session-body registration declares the session-scoped `'conversation.view'` list in its `children` table, that body renders the active entry through its renderSlot share (`only: <active id>`), and view tabs project from registration options (`id`/`order`/`label`). The chat view is this package's own entry; plugins such as ui-trajectory contribute tabs through `ctx.slots.register`, and each view owns its chrome.
 
 Approvals take over the composer through the chain this package declares: `ApprovalPanel` registers as a selector-routed `'conversation.composer'` entry (the ui-question pattern) and occupies the composer in place of the InputBar while an approval wait is pending (amber strip, justification headline, paired command line from the running call's args, one-shot refuse/allow). The `PendingApproval` domain face in `contract/slots.ts` owns the wire encoding — the `ApprovalResponsePayload` value with the audit correlation — over the runtime's `PendingWait` carrier; the broadcast `approval/resolved` frame settles the wait and restores the composer. The runtime manager projects every approval or question wait through `SessionSummary.pendingInteraction`, including sessions never instantiated; `ui-workspace` owns its sidebar presentation. Pending waits leave the message flow entirely: questions (ui-question) and approvals (ApprovalPanel) both answer through the composer takeover, so no display-only placeholder card remains. The composer's bottom-row Access seat mounts `PermissionSelect`, fed by the host-computed `permissions` projection through the standard-kit `useProjection` (key absence hides the chip); the chip opens a Menu-primitive dropdown whose kebab-case preset names render as title-case labels. Safe preset picks submit `/permission <preset>` immediately through the bar's injected `command` callback, while `danger-full-access` is presented as `Full access` and first opens an in-page Modal risk confirmation. The enabling action stays disabled until the user checks the acknowledgement; cancel, Escape, close, and mask click submit nothing.

packages/client/ui-conversation/README.zh.md

@@ -8,6 +8,8 @@
 
 常驻会话壳会跨无会话与会话状态切换而保留。没有当前会话时，它会渲染禁用输入栏；其根作用域的 `conversation.hero.workspace` slot 承载 Workspace 选择器。选择 Workspace 会连接或复用由 Host 拥有的空白会话，并在不替换会话壳的情况下打开该会话。根组件始终拥有同一个滚动容器与 Hero／编辑器子树；首个会话到达时，彼此独立的严格会话页头和主体 outlet 只填入各自区域，因此 Workspace 选择器、滚动主体、编辑器 seat 与 textarea 都保留原有 React 和 DOM identity。空白会话与活跃会话渲染相同的输入区主体；InputHub 则在 Workspace 切换间携带草稿，并将草稿镜像到会话 store。活跃阶段，会话标题栏作为普通列 chrome，仅显示当前会话标题和视图标签；fork 谱系仍保留为会话数据，不投影到标题栏。其下滚动容器（`data-conversation-scroll`）承载流动排版的各视图与 sticky 编辑器栈（统计 dock＋输入区 dock＋输入栏）。该滚动容器无条件预留自己的滚动条槽，选用编辑器 overlay 的视图也仍把它保留为滚动容器，因此无论对话记录是否滚动、无论展示哪个视图标签，输入卡片都保持同一个横向位置（[决策](../../../.agents/notes/implemented/bug-fix/2026-08-04-composer-tab-gutter-reservation.md)）。textarea 上的滚轮会链式处理：限高草稿先在本地滚动，到达边缘后再转交给该宿主。
 
+别的插件可以经 `ctx.conversation.blocks` 让某个会话的编辑器变为惰性：它设置一个携带自己本地化理由的 block，输入栏就渲染同一个禁用的 textarea，并把该理由作为 placeholder——复用无 Workspace 时的那套姿态。推送方向是约束而非偏好：知道某会话发不出消息的插件（ui-model，在没有适配器服务其路由时）本就依赖本包，因此本包读不到它们。block 只是提示性设计；无论客户端禁用了什么，宿主都会拒绝一个它路由不了的 prompt。两者同时成立时以无 Workspace 姿态为准，因为选 Workspace 是更靠前的前提。
+
 视图环是一个 slot：严格会话主体注册在 `children` 表中声明 Session scope 的 `'conversation.view'` 列表，并通过自身的 renderSlot share 渲染活跃配置项（`only: <active id>`）；视图标签页则从注册选项（`id`／`order`／`label`）投影而来。聊天视图是该包自身的配置项；ui-trajectory 等插件通过 `ctx.slots.register` 贡献标签页，每个视图负责自己的 chrome。
 
 会话页头会在标题旁声明并渲染 Session scope 的 `'conversation.session.header.actions'` 列表，使功能插件无需进入骨架即可贡献控件。编辑器链的 currency 包含当前对话 `session`；ui-subagent 会选取 one-shot 或 parent 不可用的已寻址会话，并按原因显示只读文案，而普通 InputBar 会让所有已寻址 child 仅保留 Send，因为继续执行服务不公开逐 Activation 取消操作，`session.cancel` 也会绕过其所有权。

packages/client/ui-conversation/src/client/apply.ts

@@ -15,6 +15,8 @@ import { resolveToolPath } from './contract/tool-call-model.ts'
 import { createChatStore } from './stores.ts'
 import { ConversationService } from './service.ts'
 import type { IConversation } from './service.ts'
+import { ComposerBlockRegistry } from './input/blocks.ts'
+import type { ComposerBlock } from './input/blocks.ts'
 import { InputHub } from './input/hub.ts'
 import { ComposerSubmissionPolicy } from './input/submission-policy.ts'
 import { InputBar } from './skeleton/InputBar.tsx'
@@ -54,6 +56,11 @@ const ABSENT_NOTICES = {
   getSnapshot: (): InputNotice | null => null,
   subscribe: () => () => {},
 }
+/** No session, therefore nothing to block; same one-identity rule as above. */
+const ABSENT_BLOCK = {
+  getSnapshot: (): ComposerBlock | undefined => undefined,
+  subscribe: () => () => {},
+}
 const EMPTY_LEXICON: ReadonlyMap<'/' | '@', readonly string[]> = new Map()
 const ABSENT_LEXICON = {
   getSnapshot: () => EMPTY_LEXICON,
@@ -133,6 +140,12 @@ export function apply(ctx: Context): void {
   // ctx.conversation.input by the service below sharing this one instance).
   const inputHub = new InputHub(ctx)
 
+  // The composer-block registry: a plugin that knows a session cannot send —
+  // ui-model, when no adapter serves the session's route — raises a block
+  // here, and the bar reads its own session's store. It cannot flow the other
+  // way: this package must not import the plugins that would know.
+  const composerBlocks = new ComposerBlockRegistry()
+
   // Decision 19/20: the input machine feeds every session-scope slot
   // component through the standard provide channel — the 'input' hook plus
   // the two public actions. Materialization is the shell creation trigger
@@ -167,6 +180,7 @@ export function apply(ctx: Context): void {
       'conversation.hero.workspace': { kind: 'single', scope: 'root' },
     },
     inject: (sessionId: SessionId | undefined): ConversationInjected => ({
+      hooks: { composerBlock: sessionId === undefined ? ABSENT_BLOCK : composerBlocks.storeFor(sessionId) },
       selectWorkspace: async (workspaceId) => {
         const nextId = await workspaces.connectWorkspace(workspaceId)
         if (sessionId !== undefined && nextId !== sessionId) {
@@ -351,7 +365,7 @@ export function apply(ctx: Context): void {
   // registers itself as `conversation` and lives on its own child fiber.
   // Presentation registrants depend directly on their slot declarations;
   // this service remains only where conversation actions are required.
-  ctx.plugin(ConversationService, { input: inputHub })
+  ctx.plugin(ConversationService, { input: inputHub, blocks: composerBlocks })
 
   // The bash sample rides the same declaration seam, in third-party posture
   // (ToolRow-matching Bash · {description} chrome).

packages/client/ui-conversation/src/client/contract/slots.ts

@@ -5,6 +5,7 @@ import type {
 } from '@deepseek-ai/dsh-client-ui-slots'
 import type { CommandNode, ConversationSnapshot, ObservableSnapshot, PendingInteraction, PendingWait, SessionId, ToolCallBlock, WorkspaceId } from '@deepseek-ai/dsh-client-runtime/client'
 import type {} from '@deepseek-ai/dsh-client-ui-layout/client'
+import type { ComposerBlock } from '../input/blocks.ts'
 import type { ComposerKeyboard, EditSelection, InputActions, InputNotice, InputState } from '../input/contract.ts'
 import type { createChatStore } from '../stores.ts'
 import type { ComposerSubmitGesture, InputSubmitMode } from './composer-submission.ts'
@@ -223,6 +224,12 @@ export interface ConversationInjected {
    * When a blank session is already current, carry its draft to the target.
    */
   selectWorkspace: (workspaceId: WorkspaceId) => Promise<void>
+  /**
+   * Framework-bound sources. `composerBlock` is this session's block when a
+   * plugin raised one; the reason is the blocker's own localized copy, which
+   * the root renders as the inert composer's placeholder.
+   */
+  hooks: { composerBlock: ObservableSnapshot<ComposerBlock | undefined> }
 }
 
 /** Business callbacks injected into the strict Session body seat. */
@@ -356,7 +363,7 @@ export type ConversationSlotProps =
     | 'conversation.input.left' | 'conversation.input.right'
     | 'conversation.hero.workspace'
   >
-  & ConversationInjected
+  & InjectFace<ConversationInjected>
   & PropsLocale<'conversation'>
 
 /** Full strict-session body props: per-session store, view ring, and draft mirror. */

packages/client/ui-conversation/src/client/input/blocks.ts

@@ -0,0 +1,77 @@
+/**
+ * Composer blocks: the one way another plugin stops a session's input.
+ *
+ * The composer cannot read the plugins that would know — the dependency runs
+ * ui-model → ui-conversation, never back — so a blocker pushes here and the
+ * bar reads its own session's store. A block carries the localized reason it
+ * exists, because the plugin that raised it owns that copy; the composer only
+ * knows how to render an inert textarea with a placeholder, exactly as it
+ * already does for a session with no workspace.
+ *
+ * This is an affordance, not enforcement: the Host refuses a prompt it cannot
+ * route regardless of what any client disables.
+ */
+
+import { createSnapshotStore } from '@deepseek-ai/dsh-client-runtime/client'
+import type { SessionId, SnapshotStore } from '@deepseek-ai/dsh-client-runtime/client'
+
+/** Why one session's composer is inert. */
+export interface ComposerBlock {
+  /**
+   * Localized placeholder replacing the composer's own, owned by the plugin
+   * that raised the block.
+   */
+  readonly reason: string
+}
+
+/** The registry face other plugins reach through `ctx.conversation.blocks`. */
+export interface ComposerBlocks {
+  /**
+   * Raise or clear this session's block. Idempotent: setting a block equal to
+   * the current one, or clearing an absent one, notifies nobody.
+   * @param sessionId - the session whose composer is affected.
+   * @param block - the block to raise, or undefined to clear it.
+   */
+  set(sessionId: SessionId, block: ComposerBlock | undefined): void
+  /**
+   * The store the composer subscribes to for one session. Created on first
+   * read from either side, so a blocker may raise a block before the session's
+   * composer mounts and the composer still sees it.
+   * @param sessionId - the session to observe.
+   * @returns that session's block store (undefined value = not blocked).
+   */
+  storeFor(sessionId: SessionId): SnapshotStore<ComposerBlock | undefined>
+  /**
+   * Drop one session's store. The session scope's disposer calls this; a
+   * blocker never needs to.
+   * @param sessionId - the session being torn down.
+   */
+  forget(sessionId: SessionId): void
+}
+
+/** The per-session composer-block registry (one instance per plugin fiber). */
+export class ComposerBlockRegistry implements ComposerBlocks {
+  private readonly stores = new Map<SessionId, SnapshotStore<ComposerBlock | undefined>>()
+
+  /** @inheritdoc */
+  set(sessionId: SessionId, block: ComposerBlock | undefined): void {
+    const store = this.storeFor(sessionId)
+    const current = store.getSnapshot()
+    if (current?.reason === block?.reason) return
+    store.set(block)
+  }
+
+  /** @inheritdoc */
+  storeFor(sessionId: SessionId): SnapshotStore<ComposerBlock | undefined> {
+    const existing = this.stores.get(sessionId)
+    if (existing !== undefined) return existing
+    const created = createSnapshotStore<ComposerBlock | undefined>(undefined)
+    this.stores.set(sessionId, created)
+    return created
+  }
+
+  /** @inheritdoc */
+  forget(sessionId: SessionId): void {
+    this.stores.delete(sessionId)
+  }
+}

packages/client/ui-conversation/src/client/service.ts

@@ -14,6 +14,7 @@ import type { Context } from 'cordis'
 // method) instead of the standalone helper.
 import type { ISessions, SessionFace, SessionId } from '@deepseek-ai/dsh-client-runtime/client'
 import type { QueueAction, QueueItemId } from './contract/queue.ts'
+import type { ComposerBlocks } from './input/blocks.ts'
 import type { InputService } from './input/contract.ts'
 
 /**
@@ -24,6 +25,11 @@ import type { InputService } from './input/contract.ts'
 export interface IConversation {
   /** The per-session input machine registry (InputService face). */
   readonly input: InputService
+  /**
+   * The per-session composer-block registry: how a plugin the composer
+   * cannot import makes a session's input inert with its own reason.
+   */
+  readonly blocks: ComposerBlocks
   /**
    * Send a prompt into the caller scope's session (queued turn).
    * @param text - prompt text, sent verbatim as one text block.
@@ -53,16 +59,20 @@ export interface IConversation {
 export class ConversationService extends Service implements IConversation {
   /** The per-session input machine registry (InputService face, design §5.2). */
   readonly input: InputService
+  /** The per-session composer-block registry. */
+  readonly blocks: ComposerBlocks
 
   /**
    * @param ctx - owning root context (the plugin apply context; the service
    * registers itself and follows that fiber's lifetime).
-   * @param config - carries the InputService instance constructed by the
-   * plugin apply (the same InputHub the slot inject factories close over).
+   * @param config - carries the InputService and composer-block registry
+   * constructed by the plugin apply (the same instances the slot inject
+   * factories close over).
    */
-  constructor(ctx: Context, config: { input: InputService }) {
+  constructor(ctx: Context, config: { input: InputService; blocks: ComposerBlocks }) {
     super(ctx, 'conversation')
     this.input = config.input
+    this.blocks = config.blocks
   }
 
   /**

packages/client/ui-conversation/src/client/skeleton/ConversationRoot.tsx

@@ -13,7 +13,7 @@ import css from './ConversationRoot.module.css'
 export type ConversationRootProps = ConversationSlotProps
 
 export function ConversationRoot({
-  sessionId, useSession, useSessions, useWorkspaces, useInput,
+  sessionId, useSession, useSessions, useWorkspaces, useInput, useComposerBlock,
   renderSlot, renderSlotChain, selectWorkspace, t,
 }: ConversationRootProps) {
   const openState = useSession(s => s.openState)
@@ -24,6 +24,9 @@ export function ConversationRoot({
   const cwd = useSessions(s => sessionId === undefined ? undefined : s.byId[sessionId]?.cwd)
   const summaryBlank = useSessions(s => sessionId === undefined ? undefined : s.byId[sessionId]?.blank)
   const workspaces = useWorkspaces(s => s)
+  // A plugin this package cannot import (ui-model) says this session cannot
+  // send; its reason is already localized by whoever raised it.
+  const composerBlock = useComposerBlock(block => block)
 
   const [pickerOpen, setPickerOpen] = useState(false)
   const [pendingWorkspaceId, setPendingWorkspaceId] = useState<WorkspaceId | undefined>()
@@ -126,11 +129,17 @@ export function ConversationRoot({
   // bar is ONE session-maybe slot rendered unconditionally — inert is a prop,
   // not a different tree, so the textarea DOM survives the transition.
   const inert = sessionId === undefined || (hero && chipTitle === undefined)
+  // A raised block is the same inert posture with the blocker's own reason:
+  // one disabled textarea, never a second tree. The no-workspace state wins
+  // when both hold — picking a workspace is the earlier prerequisite.
+  const blocked = !inert && composerBlock !== undefined
   const inputBar = renderSlot('conversation.composer.bar', {
     variant: hero ? 'hero' : 'composer',
     ...(inert
       ? { disabled: true, placeholder: t('placeholder.workspace') }
-      : hero ? { placeholder: t('placeholder.hero') } : {}),
+      : blocked
+        ? { disabled: true, placeholder: composerBlock.reason }
+        : hero ? { placeholder: t('placeholder.hero') } : {}),
     overlay: renderSlot('conversation.input.overlay', {}),
     leftItems: zone === undefined ? null : renderSlot('conversation.input.left', zone),
     rightItems: zone === undefined ? null : renderSlot('conversation.input.right', zone),

packages/client/ui-conversation/tests/service-orchestration.spec.ts

@@ -7,6 +7,7 @@ import { Context } from 'cordis'
 import { describe, expect, it, vi } from 'vitest'
 import { SlotTestRuntime } from '@deepseek-ai/dsh-client-test-runtime'
 import { ConversationService } from '@deepseek-ai/dsh-client-ui-conversation/client'
+import { ComposerBlockRegistry } from '../src/client/input/blocks.ts'
 import { InputHub } from '../src/client/input/hub.ts'
 
 async function bench() {
@@ -23,6 +24,7 @@ async function bench() {
   // factories); the bench passes its own instance explicitly.
   const fiber = runtime.ctx.plugin(ConversationService, {
     input: new InputHub(runtime.ctx),
+    blocks: new ComposerBlockRegistry(),
   })
   await fiber.await()
   const root = runtime.ctx.get('conversation') as ConversationService
@@ -86,6 +88,7 @@ describe('ConversationService', () => {
     const bare = new Context()
     await bare.plugin(ConversationService, {
       input: new InputHub(bare),
+      blocks: new ComposerBlockRegistry(),
     }).await()
     const orphan = bare.get('conversation') as ConversationService
     await expect(orphan.send('x')).rejects.toThrow(/sessions service unavailable/)

packages/client/ui-conversation/tests/skeleton.spec.tsx

@@ -91,6 +91,8 @@ function mount(
     omitSummaryRow?: boolean
     /** Classify the selected child as a subagent instead of an ordinary fork. */
     summaryOrigin?: 'subagent'
+    /** A composer block another plugin raised for this session. */
+    composerBlock?: { reason: string }
   } = {},
 ) {
   const root = sid('root')
@@ -224,6 +226,7 @@ function mount(
     useSessions: bindSnapshotSelector(sessions),
     useWorkspaces: bindSnapshotSelector(workspaces),
     useProjection: (() => undefined),
+    useComposerBlock: select => select(options.composerBlock),
     useInput,
     inputActions,
     renderSlot,
@@ -248,6 +251,31 @@ describe('Hero chrome', () => {
 })
 
 describe('ConversationRoot resident composer', () => {
+  it('renders the composer inert with the blocker\u2019s own reason', () => {
+    const b = mount(conversationSnapshot(), undefined, undefined, {
+      composerBlock: { reason: 'select a model first' },
+    })
+    const box = b.view.getByRole('textbox') as HTMLTextAreaElement
+    // One disabled textarea with the blocker's placeholder, never a second
+    // tree: the DOM survives the block being raised and cleared.
+    expect(box.disabled).toBe(true)
+    expect(box.placeholder).toBe('select a model first')
+    fireEvent.keyDown(box, { key: 'Enter' })
+    expect(b.sink).not.toHaveBeenCalled()
+  })
+
+  it('lets the no-workspace posture win over a block', () => {
+    // Picking a workspace is the earlier prerequisite; naming a model first
+    // would send the user somewhere they cannot act yet.
+    const b = mount(conversationSnapshot({ composerPhase: 'blank' }), [], undefined, {
+      summaryBlank: true,
+      composerBlock: { reason: 'select a model first' },
+    })
+    const box = b.view.getByRole('textbox') as HTMLTextAreaElement
+    expect(box.disabled).toBe(true)
+    expect(box.placeholder).not.toBe('select a model first')
+  })
+
   it('keeps composer text in the machine, mirrors to the chat store, and submits through the sink', () => {
     const b = mount(conversationSnapshot())
     const box = b.view.getByRole('textbox')

packages/client/ui-model/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-model/README.md
-README.md: 5f9fc65939eb747d916fa5609423d3186d1fefde
-README.zh.md: 3ed8db3095d96e48813cf5b15a206ebf4c894950
+README.md: 5a6f998476629566d35af32efa5d8bc5072a872b
+README.zh.md: 2bb22c55f1ae5af59f21e254804329d288806a90

packages/client/ui-model/README.md

@@ -6,6 +6,8 @@ Model selection plugin, browser half: TWO entries over ONE per-session directory
 
 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.

packages/client/ui-model/README.zh.md

@@ -6,6 +6,8 @@
 
 Host 报告的提供方／模型／推理（reasoning）目标是唯一的选择事实，但只有当该精确路由仍在已公布分组中时才会回显；删除该目录行会保留仍可路由的目标，但触发器会提示 `Select model`，系统不会合成陈旧行，且在用户选择已公布的模型之前不会显示 Effort 行。目录加载与选择共享一个代次计数器，旧响应不会覆盖新结果；连接重置会丢弃所有常驻目录投影，并在显示前重新拉取 Host 恢复的目标。各提供方的元数据获取失败会内联列出，同时可用分组仍可选择；选择失败会保留先前的目标和目录。
 
+当宿主报告没有适配器服务该会话的路由（`session.models.routable`）时，本插件经 `ctx.conversation.blocks` 抬起一个编辑器 block，输入框随之变为惰性并显示本插件自己的文案；恢复后无需重新加载即自动清除。它只跟随 `routable`：`null`（首次加载之前，或加载失败之后）绝不阻断，否则一个慢的宿主就会锁死一个本来能用的编辑器；目录成员关系同样不阻断，因为一条仍在服务、只是不再公布该模型的路由不在分组里，却完全可用。触发器自己的 `Select model` 回退仍然覆盖那种情形——那是显示，不是闸门。
+
 目录按会话惰性解析（`ctx.models.directoryFor(sessionId)`），随会话作用域一并释放。已寻址 subagent 会话不公开任一入口，其目录会拒绝加载、选择与重新连接刷新，因为绑定到 agent（智能体）的普通模型 RPC 会在直接 parent 继续执行 seam 之外激活持久化 child 历史。
 
 `/client` 导出面为插件本体（`apply`/`inject`）、`ModelService`、`ModelDirectory` 及其状态形状、slot 注入面类型。

packages/client/ui-model/src/client/directory.ts

@@ -15,6 +15,14 @@ import { createSnapshotStore } from '@deepseek-ai/dsh-client-runtime/client'
 export interface ModelDirectoryState {
   /** Target the host reports for the next assembled step; null before the first load. */
   current: ModelTarget | null
+  /**
+   * Whether an adapter serves the current target's route, as the host reports
+   * it — null before the first load, which is NOT the same as blocked. Read
+   * this rather than "current matches no group": catalog membership is
+   * advisory, so a route serving a model it stopped advertising is missing
+   * from the groups yet perfectly usable.
+   */
+  routable: boolean | null
   /** Successfully loaded provider groups (last good load). */
   groups: readonly ModelProviderGroup[]
   /** Provider-local failures from the last load; usable groups stay usable. */
@@ -29,7 +37,7 @@ export interface ModelDirectoryState {
 export class ModelDirectory {
   /** The shared snapshot both entries render from (uSES-safe store). */
   readonly store: SnapshotStore<ModelDirectoryState> = createSnapshotStore<ModelDirectoryState>({
-    current: null, groups: [], failures: [], status: 'idle', error: null,
+    current: null, routable: null, groups: [], failures: [], status: 'idle', error: null,
   })
 
   /** Latest operation wins; an older response never overwrites a newer one. */
@@ -65,9 +73,10 @@ export class ModelDirectory {
       this.store.update((s) => { s.status = 'error'; s.error = `${result.error.code}: ${result.error.message}` })
       throw new Error(`session.models failed: ${result.error.code}: ${result.error.message}`)
     }
-    const { current, groups, failures } = result.value
+    const { current, routable, groups, failures } = result.value
     this.store.update((s) => {
       s.current = current
+      s.routable = routable
       s.groups = groups
       s.failures = failures
       s.status = 'ready'
@@ -102,7 +111,14 @@ export class ModelDirectory {
       this.store.update((s) => { s.status = 'error'; s.error = `${result.error.code}: ${result.error.message}` })
       throw new Error(`session.selectModel failed: ${result.error.code}: ${result.error.message}`)
     }
-    this.store.update((s) => { s.current = result.value.selected; s.status = 'ready'; s.error = null })
+    // The Host validated the route before accepting it, so a selection that
+    // landed is by construction one it can serve.
+    this.store.update((s) => {
+      s.current = result.value.selected
+      s.routable = true
+      s.status = 'ready'
+      s.error = null
+    })
   }
 
   /**
@@ -115,6 +131,7 @@ export class ModelDirectory {
     ++this.generation
     this.store.update((s) => {
       s.current = null
+      s.routable = null
       s.groups = []
       s.failures = []
       s.status = 'idle'

packages/client/ui-model/src/client/index.ts

@@ -105,14 +105,16 @@ export const inject = ['command', 'connection', 'locale', 'sessions', 'slots']
  * @param ctx - client root context.
  */
 export function apply(ctx: ClientContext): void {
-  ctx.plugin(ModelService)
-
   ctx.effect(() => ctx.locale.register(NS, { zh, en }), 'ui-model: dictionaries')
 
   // Non-slot faces (the command description, the popup option builder) read
   // through the bound translate; the seat component reads the standard seat.
   const t = ctx.locale.bind(NS)
 
+  // The composer-block reason is this plugin's own copy, read at raise time so
+  // a locale change reaches the next publish.
+  ctx.plugin(ModelService, { blockReason: () => t('blocked.composer') })
+
   // Entry 1: the /model popupSelect over the shared directory. The command
   // description is registry-held text: it reads t() once at registration and
   // refreshes only on re-registration, not on locale change.

packages/client/ui-model/src/client/locales.ts

@@ -25,6 +25,7 @@ export const zh = {
   'action.reload': '重新加载',
   'warning.groupLoad': '{name} 加载失败：{message}',
   'empty.models': '没有可用的模型。',
+  'blocked.composer': '当前模型不可用，请先选择模型',
   'empty.efforts': '当前模型未提供推理等级。',
 } satisfies Record<string, string>
 
@@ -48,5 +49,6 @@ export const en = {
   'action.reload': 'Reload',
   'warning.groupLoad': '{name} failed to load: {message}',
   'empty.models': 'No models available.',
+  'blocked.composer': 'This model is unavailable — select one to continue',
   'empty.efforts': 'This model provides no reasoning effort levels.',
 } satisfies Record<ModelKey, string>

packages/client/ui-model/src/client/service.ts

@@ -36,11 +36,16 @@ export class ModelService extends Service {
 
   private readonly live: LiveState = { directories: new Map() }
 
+  /** Localized composer-block copy; this plugin owns the string it raises. */
+  private readonly blockReason: () => string
+
   /**
    * @param ctx - owning root context (the service registers itself as `models`).
+   * @param config - the bound translator for this plugin's own dictionary.
    */
-  constructor(ctx: Context) {
+  constructor(ctx: Context, config: { blockReason: () => string }) {
     super(ctx, 'models')
+    this.blockReason = config.blockReason
     ctx.on('connection/reset', () => {
       for (const directory of this.live.directories.values()) directory.resetConnected()
     })
@@ -74,6 +79,27 @@ export class ModelService extends Service {
       () => sessions.subagentAddress(sessionId) === undefined,
     )
     live.directories.set(sessionId, directory)
+    // The composer cannot read this plugin (the dependency runs one way), so
+    // the block is pushed: the Host says whether an adapter serves the
+    // session's route, and only a definite `false` makes the input inert.
+    // `null` — before the first load, or after one failed — must not, or a
+    // slow or unreachable Host would lock a working composer.
+    const conversation = this.ctx.get('conversation')
+    if (conversation !== undefined) {
+      const publish = (): void => {
+        conversation.blocks.set(sessionId, directory.store.getSnapshot().routable === false
+          ? { reason: this.blockReason() }
+          : undefined)
+      }
+      publish()
+      actx.effect(() => {
+        const stop = directory.store.subscribe(publish)
+        return () => {
+          stop()
+          conversation.blocks.set(sessionId, undefined)
+        }
+      }, 'ui-model: composer block')
+    }
     actx.effect(() => () => {
       directory.dispose()
       live.directories.delete(sessionId)

packages/client/ui-model/tests/browser-plugin.spec.ts

@@ -17,6 +17,7 @@ import type { ModelTarget } from '@deepseek-ai/dsh-client-connection/client'
 import type { CommandContribution, SelectOption } from '@deepseek-ai/dsh-client-ui-command/client'
 import type { ModelSelectInjected } from '../src/client/slots.ts'
 import { apply, inject } from '../src/client/index.ts'
+import { zh } from '../src/client/locales.ts'
 
 const sid = (k: string): SessionId => k as SessionId
 
@@ -59,7 +60,9 @@ async function bench() {
   ctx.provide('connection', { api: { sessions: {
     models: () => {
       calls.models += 1
-      return Promise.resolve({ result: { ok: true as const, value: { current, groups: GROUPS, failures: [] } } })
+      return Promise.resolve({
+        result: { ok: true as const, value: { current, routable, groups: GROUPS, failures: [] } },
+      })
     },
     selectModel: (payload: { provider: string; model: string; reasoningEffort?: string }) => {
       calls.select += 1
@@ -73,6 +76,15 @@ async function bench() {
       return Promise.resolve({ result: { ok: true as const, value: { selected: current } } })
     },
   } } })
+  // Whether the Host reports an adapter for the current route; the composer
+  // block follows this, never catalog membership.
+  let routable = true
+  const blocks = new Map<SessionId, { reason: string } | undefined>()
+  ctx.provide('conversation', {
+    blocks: {
+      set: (id: SessionId, block: { reason: string } | undefined) => { blocks.set(id, block) },
+    },
+  })
   let contribution: CommandContribution | undefined
   ctx.provide('command', {
     register(c: CommandContribution) {
@@ -115,6 +127,8 @@ async function bench() {
     hostCurrent: () => current,
     setHostCurrent: (target: ModelTarget) => { current = target },
     address: (id: SessionId) => { addressed.add(id) },
+    setRoutable: (next: boolean) => { routable = next },
+    blockOf: (key: string) => blocks.get(sid(key)),
   }
 }
 
@@ -217,6 +231,63 @@ describe('ui-model dual entry', () => {
     expect(face2.directory).not.toBe(face1.directory)
   })
 
+  it('blocks the composer only once the Host reports the route unservable', async () => {
+    const b = await bench()
+    b.mint('s1')
+    const face = b.seat().inject!(sid('s1'))
+
+    // Before the first load nothing is known. `null` is not `false`: a slow
+    // or unreachable Host must never lock a working composer.
+    expect(b.blockOf('s1')).toBeUndefined()
+    face.load()
+    await Promise.resolve()
+    await Promise.resolve()
+    expect(b.blockOf('s1')).toBeUndefined()
+
+    b.setRoutable(false)
+    b.ctx.emit('models/changed')
+    await Promise.resolve()
+    await Promise.resolve()
+    expect(b.blockOf('s1')?.reason).toBe(zh['blocked.composer'])
+
+    // Recovering clears it without a reload of the surface.
+    b.setRoutable(true)
+    b.ctx.emit('models/changed')
+    await Promise.resolve()
+    await Promise.resolve()
+    expect(b.blockOf('s1')).toBeUndefined()
+  })
+
+  it('never blocks on catalog membership alone', async () => {
+    const b = await bench()
+    b.mint('s1')
+    const face = b.seat().inject!(sid('s1'))
+    // A model the route serves but no longer advertises: the seat prompts for
+    // a selection, the composer stays usable. Blocking here would break a
+    // supported configuration (a narrowed `models` list over a live route).
+    b.setHostCurrent({ provider: 'deepseek-official', model: 'unlisted' })
+    face.load()
+    await Promise.resolve()
+    await Promise.resolve()
+    const snapshot = face.directory.getSnapshot()
+    expect(snapshot.groups.flatMap(group => group.models.map(model => model.id))).not.toContain('unlisted')
+    expect(b.blockOf('s1')).toBeUndefined()
+  })
+
+  it('clears its block when the session scope goes', async () => {
+    const b = await bench()
+    const scope = b.mint('s1')
+    b.setRoutable(false)
+    const face = b.seat().inject!(sid('s1'))
+    face.load()
+    await Promise.resolve()
+    await Promise.resolve()
+    expect(b.blockOf('s1')).toBeDefined()
+
+    await scope.fiber.dispose()
+    expect(b.blockOf('s1')).toBeUndefined()
+  })
+
   it('an unknown session fails loud at the seat inject', async () => {
     const b = await bench()
     expect(() => b.seat().inject!(sid('ghost'))).toThrow(/resolved no scope/)

packages/client/ui-model/tests/model-select.spec.tsx

@@ -32,6 +32,7 @@ const reasoning = {
 function state(overrides: Partial<ModelDirectoryState> = {}): ModelDirectoryState {
   return {
     current: { provider: 'deepseek-official', model: 'deepseek-v4-flash' },
+    routable: true,
     groups: [{
       id: 'deepseek-official',
       name: 'DeepSeek',

packages/client/ui-models/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-models/README.md
-README.md: fdd27478be25d4352462c2db0fc7eead1d1aee77
-README.zh.md: c0fd66b003593e7a535e28751f1f6d0ee80dfac1
+README.md: fe8e9851978ebd900fa43eb28f52a5a803501b63
+README.zh.md: c11ec125c6bf896c32db74161a263ee2b73c88be

packages/client/ui-models/README.md

@@ -16,7 +16,7 @@ A pi-ai profile's `models` list is edited on the card: one row per model showing
 
 **Fetch available models** asks `llm.discoverModels` about the endpoint the form **currently shows**, including a base URL edited but not yet saved and a key typed but not yet stored, so adding a provider is one pass instead of save-then-return. The reply opens a picker rather than being written: candidates already configured start unchecked, so adopting a selection never overwrites a capacity the user corrected. A provider that cannot be interrogated is a detour, not a dead end — the adapter's own message appears beside the rows, which stay editable by hand.
 
-**Add a custom provider** declares a route pi-ai does not ship. It is its own card rather than the editor with extra fields, because the route id is being chosen here and the settings address does not exist until it is: one `settings.mutate` sets the whole profile at `providers.<route>`, and the key travels separately through `credentials.set` under the same `<ROUTE>_API_KEY` derivation an existing provider uses. What a hand-declared route cannot default gates the create button — a unique **Provider ID**, an endpoint, a protocol, and at least one uniquely-identified model — so the failure names the field while the user is still looking at it. Capacities do not gate it: the adapter's fallbacks size a model the endpoint described by id alone, which is what most listings return. The protocol choices are read out of the namespace's own schema rather than a wire field or a constant, so they cannot drift from the ones the adapter accepts. The card records the conventional `apiKeyEnv` reference only when a key is typed, the same rule the editor applies, so a route declared for provider-native authentication is not born pointing at a reference nothing will ever set. The card offers the same provider-level reasoning effort the editor card does for this namespace, from one shared control: both write the same profile field, so a route declared without it would have gained the setting only on being reopened.
+**Add a custom provider** declares a route pi-ai does not ship. It is its own card rather than the editor with extra fields, because the route id is being chosen here and the settings address does not exist until it is: one `settings.mutate` sets the whole profile at `providers.<route>`, and the key travels separately through `credentials.set` under the same `<ROUTE>_API_KEY` derivation an existing provider uses. What a hand-declared route cannot default gates the create button — a unique **Provider ID**, an endpoint, a protocol, and at least one uniquely-identified model — so the failure names the field while the user is still looking at it. Capacities do not gate it: the adapter's fallbacks size a model the endpoint described by id alone, which is what most listings return. The protocol choices are read out of the namespace's own schema rather than a wire field or a constant, so they cannot drift from the ones the adapter accepts. The card records the conventional `apiKeyEnv` reference only when a key is typed, the same rule the editor applies, so a route declared for provider-native authentication is not born pointing at a reference nothing will ever set. When the profile write lands but the key write fails, the provider already exists: the card settles the fields describing it, retries the credential alone — re-running the profile write would carry the revision that write just superseded, so the Host would answer `settings-conflict` and the key could never be stored from here — and reports the created provider even if the user then cancels. The card offers the same provider-level reasoning effort the editor card does for this namespace, from one shared control: both write the same profile field, so a route declared without it would have gained the setting only on being reopened.
 
 ## Model Experience
 

packages/client/ui-models/README.zh.md

@@ -16,7 +16,7 @@ pi-ai profile 的 `models` 列表就在卡片上编辑：一行一个模型，
 
 **获取可用模型**会针对表单**当前显示**的端点调用 `llm.discoverModels`，包括已修改但尚未保存的 API 地址和已键入但尚未存储的密钥，因此新增一个提供方是一趟走完，而不是「先保存再回来」。回复会打开一个选择框而不是直接写入：已配置过的候选默认不勾选，因此采纳一次选择绝不会覆盖用户已更正的容量。无法被询问的提供方只是绕路而非死路——适配器自己的消息会显示在各行旁边，而这些行仍可手工编辑。
 
-**添加自定义提供方**用来声明 pi-ai 未提供的路由。它是独立的一张卡片而非在编辑器上加字段，因为路由 id 正是在这里被*选定*的，而在选定之前 settings 地址并不存在：一次 `settings.mutate` 在 `providers.<route>` 上设置整个 profile，密钥则经 `credentials.set` 单独传递，使用与既有提供方相同的 `<ROUTE>_API_KEY` 派生。手工声明的路由无法默认的东西会门控创建按钮——唯一的 **Provider ID**、端点、协议，以及至少一个由唯一标识的模型——因此失败会在用户仍看着该字段时点名它。容量不参与门控：端点只按 id 描述的模型（这正是多数列表返回的形态）由适配器的回退值定尺寸。协议选项读自该 namespace 自己的 schema，而非某个协议字段或常量，因此它们不会与适配器实际接受的集合发生漂移。只有键入了密钥，这张卡片才记录约定的 `apiKeyEnv` 引用，与编辑器同一条规则，因此一条为提供方原生认证声明的路由不会一出生就指向一个永远不会被设置的引用。这张卡片提供与编辑器卡片在该 namespace 下相同的提供方级推理等级，两者共用同一个控件：它们写的是同一个 profile 字段，若声明时没有它，这个设置就会等到重新打开编辑时才凭空出现。
+**添加自定义提供方**用来声明 pi-ai 未提供的路由。它是独立的一张卡片而非在编辑器上加字段，因为路由 id 正是在这里被*选定*的，而在选定之前 settings 地址并不存在：一次 `settings.mutate` 在 `providers.<route>` 上设置整个 profile，密钥则经 `credentials.set` 单独传递，使用与既有提供方相同的 `<ROUTE>_API_KEY` 派生。手工声明的路由无法默认的东西会门控创建按钮——唯一的 **Provider ID**、端点、协议，以及至少一个由唯一标识的模型——因此失败会在用户仍看着该字段时点名它。容量不参与门控：端点只按 id 描述的模型（这正是多数列表返回的形态）由适配器的回退值定尺寸。协议选项读自该 namespace 自己的 schema，而非某个协议字段或常量，因此它们不会与适配器实际接受的集合发生漂移。只有键入了密钥，这张卡片才记录约定的 `apiKeyEnv` 引用，与编辑器同一条规则，因此一条为提供方原生认证声明的路由不会一出生就指向一个永远不会被设置的引用。当 profile 写入成功而密钥写入失败时，提供方其实已经存在：卡片会把描述它的字段定住，只重试凭据——再跑一次 profile 写入会带着刚被自己这次写入取代的 revision，宿主将以 `settings-conflict` 应答，密钥就再也无法从这里存下——并且即使用户随后取消，也照实报告提供方已创建。这张卡片提供与编辑器卡片在该 namespace 下相同的提供方级推理等级，两者共用同一个控件：它们写的是同一个 profile 字段，若声明时没有它，这个设置就会等到重新打开编辑时才凭空出现。
 
 ## 模型体验
 

packages/client/ui-models/src/client/CustomProviderCard.tsx

@@ -74,7 +74,15 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
   const [models, setModels] = useState<readonly ModelDraft[]>([])
   const [busy, setBusy] = useState(false)
   const [failure, setFailure] = useState<string | undefined>(undefined)
+  /**
+   * The profile write landed. Only the key write can still be outstanding, so
+   * the fields that describe the provider are settled and the retry path is
+   * the credential alone.
+   */
+  const [committed, setCommitted] = useState(false)
   const disabled = props.readOnly || busy
+  /** Everything but the key stops being editable once the provider exists. */
+  const profileDisabled = disabled || committed
 
   const routeInvalid = route.length > 0 && !ROUTE_PATTERN.test(route)
   const routeTaken = taken.includes(route)
@@ -98,34 +106,42 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
   /** Perform the create, returning a failure message or undefined. */
   const createOnce = async (): Promise<string | undefined> => {
     const keyRef = deriveKeyRef(route)
-    const storesKey = keyDraft.trim().length > 0
-    const profile = {
-      ...displayName.length === 0 ? {} : { displayName },
-      // The profile names the conventional reference only when this card is
-      // about to store a key, matching the editor: a route declared with the
-      // key left blank keeps its provider-native auth path (a credential
-      // chain, ADC) instead of resolving a reference nothing ever sets.
-      ...storesKey ? { apiKeyEnv: keyRef } : {},
-      api: protocol,
-      baseURL,
-      // Inherit is the field being absent, not an empty string: the schema
-      // types it as an effort name, and an empty one would fail the write.
-      ...effort === undefined ? {} : { [EFFORT_FIELD['pi-ai']]: effort },
-      models: models.map(model => ({ ...model })),
+    const normalizedKey = keyDraft.trim()
+    const storesKey = normalizedKey.length > 0
+    if (!committed) {
+      const profile = {
+        ...displayName.length === 0 ? {} : { displayName },
+        // The profile names the conventional reference only when this card is
+        // about to store a key, matching the editor: a route declared with the
+        // key left blank keeps its provider-native auth path (a credential
+        // chain, ADC) instead of resolving a reference nothing ever sets.
+        ...storesKey ? { apiKeyEnv: keyRef } : {},
+        api: protocol,
+        baseURL,
+        // Inherit is the field being absent, not an empty string: the schema
+        // types it as an effort name, and an empty one would fail the write.
+        ...effort === undefined ? {} : { [EFFORT_FIELD['pi-ai']]: effort },
+        models: models.map(model => ({ ...model })),
+      }
+      const response = await api.settings.mutate({
+        ns: NS,
+        ops: [{ op: 'set', path: ['providers', route], value: profile }],
+        // `taken` is a snapshot too, so the id check alone cannot see a route
+        // declared after this card opened; the revision makes that race a
+        // `settings-conflict` instead of a write over the other profile.
+        expectedRevision: openedAt,
+      })
+      if (!response.result.ok) return response.result.error.message
+      // The provider now exists. A retry after the key write below fails must
+      // not re-run this mutate: the revision it holds is the one this write
+      // just superseded, so the Host would answer `settings-conflict` and the
+      // key could never be stored from this card at all.
+      setCommitted(true)
     }
-    const response = await api.settings.mutate({
-      ns: NS,
-      ops: [{ op: 'set', path: ['providers', route], value: profile }],
-      // `taken` is a snapshot too, so the id check alone cannot see a route
-      // declared after this card opened; the revision makes that race a
-      // `settings-conflict` instead of a write over the other profile.
-      expectedRevision: openedAt,
-    })
-    if (!response.result.ok) return response.result.error.message
     if (storesKey) {
-      const stored = await api.credentials.set({ ref: keyRef, value: keyDraft })
+      const stored = await api.credentials.set({ ref: keyRef, value: normalizedKey })
       // The profile landed; saying the key did not is the only honest report,
-      // and the row is now editable so the key can be entered again there.
+      // and the retry above now goes straight back to this write.
       if (!stored.result.ok) return stored.result.error.message
     }
     return undefined
@@ -163,7 +179,7 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
           value={route}
           placeholder="acme-gateway"
           aria-label={t('customRoute')}
-          disabled={disabled}
+          disabled={profileDisabled}
           onChange={(event) => { setRoute(event.target.value) }}
         />
       </div>
@@ -178,7 +194,7 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
           value={displayName}
           placeholder={route.length === 0 ? t('customDisplayName') : route}
           aria-label={t('customDisplayName')}
-          disabled={disabled}
+          disabled={profileDisabled}
           onChange={(event) => { setDisplayName(event.target.value) }}
         />
       </div>
@@ -190,7 +206,7 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
           value={baseURL}
           placeholder="https://gateway.example/v1"
           aria-label={t('baseUrl')}
-          disabled={disabled}
+          disabled={profileDisabled}
           onChange={(event) => { setBaseURL(event.target.value) }}
         />
       </div>
@@ -200,7 +216,7 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
           className={styles['input']}
           value={protocol}
           aria-label={t('customApi')}
-          disabled={disabled}
+          disabled={profileDisabled}
           onChange={(event) => { setProtocol(event.target.value) }}
         >
           {protocols.map(choice => <option key={choice} value={choice}>{choice}</option>)}
@@ -226,7 +242,7 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
         value={effort ?? ''}
         onChange={setEffort}
         t={t}
-        disabled={disabled}
+        disabled={profileDisabled}
       />
       <ModelListEditor
         models={models}
@@ -239,7 +255,7 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
         }}
         api={api}
         t={t}
-        disabled={disabled}
+        disabled={profileDisabled}
       />
       {failure !== undefined ? <p className={styles['error']}>{failure}</p> : null}
       {/* Only the gates with something to say render; the route-id gate has its
@@ -251,7 +267,7 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
         submitDisabled={disabled || !ready}
         submitLabel="create"
         submitBusyLabel="creating"
-        onCancel={() => { props.onClose(false) }}
+        onCancel={() => { props.onClose(committed) }}
         onSubmit={() => { void create() }}
       />
     </div>

packages/client/ui-models/tests/provider-form.spec.tsx

@@ -650,8 +650,11 @@ describe('provider rows', () => {
 })
 
 describe('hand-declared providers', () => {
-  function mountCard(overrides: Partial<Parameters<typeof CustomProviderCard>[0]> = {}) {
-    const scripted = scriptedFace()
+  function mountCard(
+    overrides: Partial<Parameters<typeof CustomProviderCard>[0]> = {},
+    wire: Parameters<typeof scriptedFace>[0] = {},
+  ) {
+    const scripted = scriptedFace(wire)
     const onClose = vi.fn()
     render(
       <CustomProviderCard
@@ -736,6 +739,60 @@ describe('hand-declared providers', () => {
     expect(firstMutate(second.mutate).ops[0]).not.toHaveProperty('value.reasoning')
   })
 
+  it('retries only the key after the profile landed, and reports the provider on cancel', async () => {
+    const set = vi.fn()
+      .mockResolvedValueOnce(fail('credential store is read-only', 'credential-rejected'))
+      .mockResolvedValueOnce(ok({}))
+    const { mutate, onClose } = mountCard({}, { set })
+
+    fireEvent.change(screen.getByLabelText(en.customRoute), { target: { value: 'acme' } })
+    fireEvent.change(screen.getByLabelText(en.baseUrl), { target: { value: 'https://acme.test/v1' } })
+    fireEvent.change(screen.getByLabelText(en.keyInput), { target: { value: '  gw-key  ' } })
+    fireEvent.click(screen.getByRole('button', { name: en.addModel }))
+    fireEvent.change(screen.getByLabelText(`${en.modelId} 1`), { target: { value: 'm' } })
+    fireEvent.click(screen.getByText(en.create))
+
+    // The profile landed; only the key failed. The card says so and stays open.
+    await waitFor(() => { expect(screen.getByText('credential store is read-only')).toBeTruthy() })
+    expect(onClose).not.toHaveBeenCalled()
+    expect(mutate).toHaveBeenCalledTimes(1)
+    // The key is stored trimmed, matching the editor.
+    expect(set).toHaveBeenNthCalledWith(1, { ref: 'ACME_API_KEY', value: 'gw-key' })
+
+    // The provider exists now, so the fields describing it are settled and
+    // only the key can still be corrected.
+    expect(screen.getByLabelText<HTMLInputElement>(en.customRoute).disabled).toBe(true)
+    expect(screen.getByLabelText<HTMLInputElement>(en.baseUrl).disabled).toBe(true)
+    expect(screen.getByLabelText<HTMLInputElement>(en.keyInput).disabled).toBe(false)
+
+    fireEvent.change(screen.getByLabelText(en.keyInput), { target: { value: 'gw-key-2' } })
+    fireEvent.click(screen.getByText(en.create))
+    await waitFor(() => { expect(onClose).toHaveBeenCalledWith(true) })
+    // Re-running the profile write would carry the revision this card's own
+    // first write superseded, so the Host would answer settings-conflict and
+    // the key could never be stored from here at all.
+    expect(mutate).toHaveBeenCalledTimes(1)
+    expect(set).toHaveBeenNthCalledWith(2, { ref: 'ACME_API_KEY', value: 'gw-key-2' })
+  })
+
+  it('reports the created provider when cancelled after its profile landed', async () => {
+    const set = vi.fn().mockResolvedValue(fail('nope', 'credential-rejected'))
+    const { onClose } = mountCard({}, { set })
+
+    fireEvent.change(screen.getByLabelText(en.customRoute), { target: { value: 'acme' } })
+    fireEvent.change(screen.getByLabelText(en.baseUrl), { target: { value: 'https://acme.test/v1' } })
+    fireEvent.change(screen.getByLabelText(en.keyInput), { target: { value: 'gw-key' } })
+    fireEvent.click(screen.getByRole('button', { name: en.addModel }))
+    fireEvent.change(screen.getByLabelText(`${en.modelId} 1`), { target: { value: 'm' } })
+    fireEvent.click(screen.getByText(en.create))
+    await waitFor(() => { expect(screen.getByText('nope')).toBeTruthy() })
+
+    // Walking away leaves a real provider behind; reporting no change would
+    // leave the page without the row it now has.
+    fireEvent.click(screen.getByText(en.cancel))
+    expect(onClose).toHaveBeenCalledWith(true)
+  })
+
   it('names the blocked gate under the form, and nothing once it is satisfied', () => {
     mountCard()
     fireEvent.change(screen.getByLabelText(en.customRoute), { target: { value: 'acme' } })