fix(chat): retain assistant nodes and steering echoes

apps/web/tests/live-interactions.e2e.ts

@@ -50,6 +50,7 @@ const AUTH_PROVIDER_MESSAGE = 'Authentication Fails, Your api key: sk-preview-se
 // model call.
 const PROMPT = 'Reply with a one-sentence description of event sourcing, then stop.'
 const RUNNING_DRAFT = 'Queue this follow-up while the current turn is running.'
+const RETRY_PARTIAL = 'This partial reply must disappear when the attempt fails.'
 
 /** turn/end reasons observed, in order. */
 function turnEndReasons(events: SessionEvent[]): string[] {
@@ -270,21 +271,44 @@ describe('web e2e: live-turn interactions (cancel / error / retry)', () => {
     expect(derived).toHaveLength(1)
     await launch(() => ({
       patches: [
-        { at: 0, entry: { kind: 'throw', chunks: [], message: 'upstream 503', code: 'SERVER' } },
+        { at: 0, entry: {
+          kind: 'throw', message: 'upstream 503', code: 'SERVER',
+          chunks: [
+            { type: 'block-start', index: 0, blockType: 'text' },
+            { type: 'text-delta', index: 0, text: RETRY_PARTIAL },
+          ],
+        } },
         // Append the fixture's own success as the retry attempt — single-
         // sourced from the recording, never copied into a committed sidecar.
         { at: 1, entry: derived[0]! },
       ],
     }))
     onTestFailed(() => saveFailureShot(page, 'web-e2e-retry'))
-    // llm-retry backs off ~500ms before the second attempt.
-    const { settled } = await sendPrompt(60_000)
-    await settled
+    const releaseFailure = Promise.withResolvers<undefined>()
+    // Retirement must follow a visible partial, not race the first browser paint.
+    const stopHolding = scaffold!.ctx.on('llm/stream', async function* (_request, next) {
+      for await (const chunk of next()) {
+        yield chunk
+        if (chunk.type === 'text-delta' && chunk.text === RETRY_PARTIAL) await releaseFailure.promise
+      }
+    })
+    try {
+      const { settled } = await sendPrompt(60_000)
+      await page.getByText(RETRY_PARTIAL, { exact: true }).waitFor({ timeout: 15_000 })
+      releaseFailure.resolve(undefined)
+      await settled
+    } finally {
+      releaseFailure.resolve(undefined)
+      stopHolding()
+    }
     expect(turnEndReasons(sessionEvents).at(-1)).toBe('completed')
     // The durable retry record proves the second attempt (request/header logs
     // only on change, so attempt count is invisible there).
     expect(sessionEvents.filter(e => e.type === 'llm/retry').length).toBeGreaterThanOrEqual(1)
     await expect.poll(() => page.getByText('event sourcing', { exact: false }).count(), { timeout: 10_000 }).toBeGreaterThan(0)
+    await expect.poll(() => page.getByText(RETRY_PARTIAL, { exact: true }).count()).toBe(0)
+    expect(tripwire.pageErrors).toEqual([])
+    expect(tripwire.warnings).toEqual([])
     // Golden of the recovered end-state: the discarded partial stays absent,
     // while the settled retry row remains as durable recovery context.
     const snapshot = await captureStableAria(page, '[class*="centerCol"]', scaffold!.workspaceCwd)

apps/web/tests/steering.e2e.ts

@@ -235,9 +235,28 @@ describe('web e2e: composer shortcut steers directly', () => {
     await composer.waitFor({ timeout: 30_000 })
     const pendingSteering = page.locator('[data-pending-steering]').filter({ hasText: STEER })
     await pendingSteering.waitFor({ timeout: 10_000 })
-    await composer.getByRole('radio', { name: 'Yes' }).click()
-    await composer.getByRole('radio', { name: 'Yes' }).press('Enter')
-    await settled
+    const admission = Promise.withResolvers<undefined>()
+    let claimed = false
+    const stopHolding = scaffold.ctx.on('agent/pre-step', async (payload, next) => {
+      if (payload.messages.some(message => message.content.some(block => block.type === 'text' && block.text === STEER))) {
+        claimed = true
+        await admission.promise
+      }
+      return next()
+    })
+    try {
+      await composer.getByRole('radio', { name: 'Yes' }).click()
+      await composer.getByRole('radio', { name: 'Yes' }).press('Enter')
+      await expect.poll(() => claimed, { timeout: 10_000 }).toBe(true)
+      await page.evaluate(() => new Promise<void>((resolve) => {
+        requestAnimationFrame(() => requestAnimationFrame(() => { resolve() }))
+      }))
+      expect(await page.getByText(STEER, { exact: true }).count()).toBe(1)
+    } finally {
+      admission.resolve(undefined)
+      stopHolding()
+      await settled
+    }
 
     const steerEvents = claimedMessages(sessionEvents, STEER)
     expect(steerEvents).toHaveLength(1)

packages/api/session-controller/src/client/sessions/session.ts

@@ -6,6 +6,7 @@ import { randomUUID } from '@deepseek-ai/dsh-util-crypto'
 import type { AttachmentIdType, FileAttachmentRef, ImageAttachmentRef } from '@deepseek-ai/dsh-attachment'
 import type { SubagentAddress } from '@deepseek-ai/dsh-subagent/client'
 import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
+import type { UserMessage } from '@deepseek-ai/dsh-llm/types'
 import { SessionLogOffset, SessionSeq, type SessionId } from '@deepseek-ai/dsh-session/types'
 import { SessionEventStream } from '../transport.ts'
 import type { SessionJournalChange } from '../transport.ts'
@@ -25,7 +26,7 @@ import type {
 } from '../contract/snapshot.ts'
 import { MutableSessionEventSource } from '../contract/events.ts'
 import type {
-  SessionEventLikeEntry, SessionLiveEventEntry,
+  SessionEventLike, SessionEventLikeEntry, SessionLiveEventEntry,
 } from '../contract/events.ts'
 import { Notifier } from './notifier.ts'
 import { isRemoteFailure } from '@deepseek-ai/dsh-api-gateway/client'
@@ -124,6 +125,9 @@ export class Session implements SessionFace {
   /** Per-echo settlement state; `retiring` latches the first observation so a
    *  Inbox projection and its durable event cannot both retire one echo. */
   private readonly submissionSettlements = new Map<SessionRequestId, {
+    readonly placement: PendingSubmission['placement']
+    /** Latest received next-step position; null means claimed but not yet admitted. */
+    receipt?: { readonly seq: number; readonly index: number | null }
     readonly onRetire?: ((retirement: PendingSubmissionRetirement) => void) | undefined
     retiring: boolean
   }>()
@@ -209,16 +213,15 @@ export class Session implements SessionFace {
    */
   beginSubmission(input: BeginSubmissionInput): SubmissionHandle {
     const requestId = randomUUID() as SessionRequestId
+    const placement = this.running ? input.mode === 'steer' ? 'steering' : 'queued' : 'transcript'
     this.pendingSubmissions = [...this.pendingSubmissions, {
       requestId,
-      placement: this.running
-        ? input.mode === 'steer' ? 'steering' : 'queued'
-        : 'transcript',
+      placement,
       time: Date.now(),
       text: input.text,
       attachments: input.attachments,
     }]
-    this.submissionSettlements.set(requestId, { onRetire: input.onRetire, retiring: false })
+    this.submissionSettlements.set(requestId, { placement, onRetire: input.onRetire, retiring: false })
     // The blank → engaging edge flips here, ahead of prompt(): the composer
     // docks and the echo renders on the click's own frame.
     this.promptAttempted = true
@@ -666,6 +669,10 @@ export class Session implements SessionFace {
     if (projections !== undefined) this.projections.seed(projections)
     this.eventSource.replace(visible, hasMore)
     for (const entry of visible) this.observeSubmissionEvent(entry.event)
+    if (projections !== undefined) {
+      const inbox = projections.values.inbox as InboxState | undefined
+      this.observeSteeringInsertions(inbox?.['next-step'] ?? [], 0, projections.asOfSeq)
+    }
     this.notifier.markDirty()
   }
 
@@ -724,36 +731,58 @@ export class Session implements SessionFace {
   }
 
   /** Observe durable acceptance even when insertion and claim share one projection notification. */
-  private observeSubmissionEvent(event: { readonly type: string; readonly data?: unknown }): void {
+  private observeSubmissionEvent(event: SessionEventLike): void {
     if (this.submissionSettlements.size === 0) return
     if (event.type === 'agent/inbox/spliced') {
-      const splice = event.data as { readonly inserted?: unknown } | undefined
-      if (Array.isArray(splice?.inserted)) {
-        for (const message of splice.inserted) this.observeSubmissionEvent({ type: 'user/message', data: message })
+      const { target, start, removedCount = 0, inserted, outcome } = event.data
+      if (target === 'next-step') {
+        for (const [requestId, settlement] of this.submissionSettlements) {
+          const receipt = settlement.receipt
+          if (receipt === undefined || receipt.index === null || receipt.seq >= event.seq) continue
+          const removed = receipt.index >= start && receipt.index < start + removedCount
+          if (removed && outcome === 'canceled') this.retireFailedSubmission(requestId)
+          else settlement.receipt = {
+            seq: event.seq,
+            index: removed ? null : receipt.index < start ? receipt.index : receipt.index + inserted.length - removedCount,
+          }
+        }
+        this.observeSteeringInsertions(inserted, start, event.seq)
+      }
+      for (const message of inserted) this.observeSubmissionMessage(message, false)
+      return
+    }
+    if (event.type === 'request/context' || event.type === 'turn/end') {
+      for (const [requestId, settlement] of this.submissionSettlements) {
+        if (settlement.receipt?.index === null && settlement.receipt.seq < event.seq) this.retireFailedSubmission(requestId)
       }
       return
     }
-    if (event.type !== 'user/message') return
-    // Structural read: window entries may be compact history records, so the
-    // fields are narrowed rather than trusted (same posture as Conversation
-    // assembly matchers).
-    const data = event.data as { readonly source?: unknown; readonly content?: unknown } | undefined
-    const source = data?.source as { readonly kind?: unknown; readonly rpcId?: unknown } | undefined
-    if (source?.kind !== 'user' || typeof source.rpcId !== 'string') return
-    this.scheduleObservedRetirement(source.rpcId as SessionRequestId, attachmentRefsIn(data?.content))
+    if (event.type === 'user/message') this.observeSubmissionMessage(event.data, true)
   }
 
-  /** Retire local echoes when their accepted messages appear in the durable Inbox projection. */
+  private observeSteeringInsertions(messages: readonly UserMessage[], start: number, seq: number): void {
+    for (const [index, message] of messages.entries()) {
+      const source = message.source
+      if (source.kind !== 'user' || !('rpcId' in source)) continue
+      const settlement = this.submissionSettlements.get(source.rpcId)
+      if (settlement?.placement !== 'steering' || settlement.retiring || (settlement.receipt?.seq ?? -1) > seq) continue
+      settlement.receipt = { seq, index: start + index }
+    }
+  }
+
+  private observeSubmissionMessage(message: UserMessage, admitted: boolean): void {
+    const source = message.source
+    if (source.kind !== 'user' || !('rpcId' in source)) return
+    if (!admitted && this.submissionSettlements.get(source.rpcId)?.placement === 'steering') return
+    this.scheduleObservedRetirement(source.rpcId, attachmentRefsIn(message.content))
+  }
+
+  /** Retire non-steering echoes when the Inbox accepts their queue occurrences. */
   private observeSubmissionInbox(): void {
     if (this.submissionSettlements.size === 0) return
     const inbox = this.projections.get('inbox') as InboxState | undefined
     if (inbox === undefined) return
-    for (const message of [...inbox['next-turn'], ...inbox['next-step']]) {
-      const source = message.source
-      if (source.kind === 'user' && 'rpcId' in source) {
-        this.scheduleObservedRetirement(source.rpcId, attachmentRefsIn(message.content))
-      }
-    }
+    for (const message of [...inbox['next-turn'], ...inbox['next-step']]) this.observeSubmissionMessage(message, false)
   }
 
   /**

packages/api/session-controller/tests/session-pending-submissions.client.spec.ts

@@ -193,6 +193,77 @@ describe('observed retirement', () => {
     expect(onRetire).toHaveBeenCalledExactlyOnceWith({ reason: 'observed', attachments: refs })
   })
 
+  it('keeps a running steer echo through accepted and claimed Inbox states until transcript admission', async ({ mock, start }) => {
+    const session = await sessionBench(mock, start, SID)
+    await session.open()
+    session.handleRunning(true)
+    const onRetire = vi.fn()
+    const handle = session.beginSubmission({ mode: 'steer', text: 'accepted', attachments: [], onRetire })
+    const refs = [imageRef('steer-image')]
+    const message = queuedItem(handle.requestId, refs)
+    const echo = session.getSnapshot().pendingSubmissions[0]
+    session.projections.apply('inbox', { 'next-turn': [], 'next-step': [message] }, SessionSeq(0))
+    await settleFrames()
+    expect(session.getSnapshot().pendingSubmissions).toEqual([echo])
+    await pushEvent(mock, {
+      type: 'agent/inbox/spliced', seq: SessionSeq(0), time: 1,
+      data: { target: 'next-step', start: 0, inserted: [message] },
+    })
+    await pushEvent(mock, {
+      type: 'agent/inbox/spliced', seq: SessionSeq(1), time: 2,
+      data: { target: 'next-step', start: 0, removedCount: 1, inserted: [] },
+    })
+    session.projections.apply('inbox', { 'next-turn': [], 'next-step': [] }, SessionSeq(1))
+    await settleFrames()
+    expect(session.getSnapshot().pendingSubmissions).toEqual([echo])
+    expect(onRetire).not.toHaveBeenCalled()
+    await pushEvent(mock, {
+      type: 'user/message', seq: SessionSeq(2), time: 3, surfaceOp: 'append', data: message,
+    })
+    await settleFrames()
+    expect(session.getSnapshot().pendingSubmissions).toEqual([])
+    expect(onRetire).toHaveBeenCalledExactlyOnceWith({ reason: 'observed', attachments: refs })
+  })
+
+  it('retires canceled or unadmitted steering without removing still-pending input', async ({ mock, start }) => {
+    const session = await sessionBench(mock, start, SID)
+    await session.open()
+    session.handleRunning(true)
+    const canceled = vi.fn()
+    const rejected = vi.fn()
+    const first = session.beginSubmission({ mode: 'steer', text: 'cancel', attachments: [], onRetire: canceled })
+    const second = session.beginSubmission({ mode: 'steer', text: 'reject', attachments: [], onRetire: rejected })
+    const unclaimed = session.beginSubmission({ mode: 'steer', text: 'later', attachments: [] })
+    const foreign = createUserMessage({ source: { kind: 'user' }, content: [] })
+    await pushEvent(mock, {
+      type: 'agent/inbox/spliced', seq: SessionSeq(0), time: 1,
+      data: { target: 'next-step', start: 0, inserted: [queuedItem(first.requestId), queuedItem(second.requestId)] },
+    })
+    await pushEvent(mock, {
+      type: 'agent/inbox/spliced', seq: SessionSeq(1), time: 2,
+      data: { target: 'next-step', start: 0, inserted: [foreign] },
+    })
+    await pushEvent(mock, {
+      type: 'agent/inbox/spliced', seq: SessionSeq(2), time: 3,
+      data: { target: 'next-step', start: 1, removedCount: 1, inserted: [], outcome: 'canceled' },
+    })
+    expect(canceled).toHaveBeenCalledExactlyOnceWith({ reason: 'failed' })
+    expect(rejected).not.toHaveBeenCalled()
+    await pushEvent(mock, {
+      type: 'agent/inbox/spliced', seq: SessionSeq(3), time: 4,
+      data: { target: 'next-step', start: 0, removedCount: 2, inserted: [] },
+    })
+    await pushEvent(mock, {
+      type: 'agent/inbox/spliced', seq: SessionSeq(4), time: 5,
+      data: { target: 'next-step', start: 0, inserted: [queuedItem(unclaimed.requestId)] },
+    })
+    await pushEvent(mock, {
+      type: 'turn/end', seq: SessionSeq(5), time: 6, data: { turn: 1, reason: { kind: 'blocked' } },
+    })
+    expect(rejected).toHaveBeenCalledExactlyOnceWith({ reason: 'failed' })
+    expect(session.getSnapshot().pendingSubmissions.map(echo => echo.requestId)).toEqual([unclaimed.requestId])
+  })
+
   it('a queue occurrence carrying the rpcId retires the echo (running-turn submissions)', async ({ mock, start }) => {
     const session = await sessionBench(mock, start, SID)
     const retirements: PendingSubmissionRetirement[] = []

packages/client/ui-chat/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-chat/README.md
-README.md: b383d74805dfd9e37c4b69136c15a63ca087e10d
-README.zh.md: 046036f0919598afb363a97a984d6a137550d12b
+README.md: 34ac2d6e79b6ec67583b7a0f85d48e71f7fb27b1
+README.zh.md: bcb521100ff11b59e1e1c2b5a47b45cabb1ce57d

packages/client/ui-chat/README.md

@@ -40,6 +40,8 @@ Settings → General → Open chat links in selects the destination for ordinary
 
 Chat omits system-prompt, ordinary Context injection, and `permission` command rows in every work-details mode. The filter changes neither recorded Session events nor Trajectory inspection. Non-human Turn triggers remain independent notices; other command rows remain in Chat.
 
+When an Assistant attempt retires without a visible message, Chat hides its already-published Node instead of removing its key. A retry in the same Step reuses that key when visible content returns. This also applies when the loaded window lacks the Step start.
+
 <a id="command-and-failure-rows"></a>
 ## Command and failure rows
 
@@ -70,6 +72,8 @@ The completed-turn action footer follows the recorded Turn end. Its action row s
 
 Preference menus restore focus to their trigger without scrolling before publishing a new selection.
 
+Local steering echoes remain mounted through Inbox acceptance and claim until the durable message arrives. Matching Host-pending rows stay hidden during this handoff, and the same request does not trigger tail following twice.
+
 Work-details modes control process-group display and reasoning previews; eligible completed Turns fold their process without hiding the final answer. The [business-rule reference](src/client/conversation-nodes/README.md#display-modes) contains the mode table, title behavior, whole-Turn eligibility, clocks, and disclosure resets.
 
 -----

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

@@ -40,6 +40,8 @@ Chat 在节点列表外通过一个 `MarkdownDelegateProvider` 提供文件及 H
 
 Chat 在所有工作过程展示模式下都不显示系统提示词行、普通上下文注入和 `permission` 命令行。该过滤不改变已记录的 Session 事件或 Trajectory 查看能力。非人工轮次触发仍作为独立通知显示，其他命令行仍保留在 Chat 中。
 
+Assistant 尝试结束且没有可见消息时，Chat 隐藏已发布的 Node，不移除其 key。同一 Step 的重试再次产生可见内容时，复用该 key。已加载窗口缺少 Step 起点时也遵循此规则。
+
 <a id="command-and-failure-rows"></a>
 ## 指令与失败行
 
@@ -70,6 +72,8 @@ Chat 在所有工作过程展示模式下都不显示系统提示词行、普通
 
 偏好菜单在发布新选择之前，先将焦点还给触发按钮，且不引起滚动。
 
+本地 steering 回显在 Inbox 接受与领取期间保持挂载，直到持久消息到达。交接期间隐藏同请求的 Host 待处理行，同一请求不会重复触发跟随底部。
+
 工作过程展示模式控制过程组显示与推理预览；符合条件的已完成轮次折叠过程，但不隐藏最终答案。[业务规则明细](src/client/conversation-nodes/README.zh.md#display-modes) 统一说明模式表、组头行为、整轮折叠资格、时钟与开合重置。
 
 -----

packages/client/ui-chat/src/client/chat/ChatView.tsx

@@ -38,7 +38,7 @@ function observedRpcIds(
   order: readonly string[],
   nodes: ChatSnapshot['nodes'],
   inbox: InboxState | undefined,
-): ReadonlySet<string> {
+): { readonly durable: ReadonlySet<string>; readonly pending: ReadonlySet<string> } {
   const observed = new Set<string>()
   for (const key of order) {
     const node = nodes.get(key)
@@ -48,10 +48,11 @@ function observedRpcIds(
       | undefined
     if (source?.kind === 'user' && typeof source.rpcId === 'string') observed.add(source.rpcId)
   }
+  const pending = new Set<string>()
   for (const { source } of [...inbox?.['next-turn'] ?? [], ...inbox?.['next-step'] ?? []]) {
-    if (source.kind === 'user' && 'rpcId' in source) observed.add(source.rpcId)
+    if (source.kind === 'user' && 'rpcId' in source) pending.add(source.rpcId)
   }
-  return observed
+  return { durable: observed, pending }
 }
 
 type ChatNodeListProps = Omit<ComponentProps<typeof ChatNodeSeat>, 'nodeKey' | 'groupPart'> & {
@@ -141,7 +142,7 @@ export function ChatView({
     setFileOpenBusy(false)
   }, [])
 
-  const pendingSteering = useMemo(
+  const inboxSteering = useMemo(
     () => inbox?.['next-step'].filter(message => message.source.kind === 'user') ?? [],
     [inbox],
   )
@@ -153,9 +154,15 @@ export function ChatView({
     if (pendingSubmissions.length === 0) return pendingSubmissions
     const observed = observedRpcIds(order, nodeStore, inbox)
     return pendingSubmissions.filter(submission => (
-      submission.placement !== 'queued' && !observed.has(submission.requestId)
+      submission.placement !== 'queued' && !observed.durable.has(submission.requestId)
+      && (submission.placement === 'steering' || !observed.pending.has(submission.requestId))
     ))
   }, [pendingSubmissions, order, nodeStore, inbox])
+  const pendingSteering = useMemo(() => {
+    const local = new Set(visibleSubmissions.filter(submission => submission.placement === 'steering')
+      .map(submission => submission.requestId))
+    return inboxSteering.filter(({ source }) => source.kind !== 'user' || !('rpcId' in source) || !local.has(source.rpcId))
+  }, [inboxSteering, visibleSubmissions])
   const renderMessageImages = useCallback<RenderMessageImages>(
     owner => renderSlot('conversation.message.images', { ...owner, loadImage }),
     [loadImage, renderSlot],
@@ -164,11 +171,14 @@ export function ChatView({
   const firstKey = order[0]
   const firstSeq = firstKey === undefined ? null : nodeStore.get(firstKey)?.anchorSeq ?? null
   const lastKey = order.at(-1) ?? null
+  const latestSteering = pendingSteering.at(-1)
+  const steeringId = latestSteering?.source.kind === 'user' && 'rpcId' in latestSteering.source
+    ? latestSteering.source.rpcId : latestSteering?.id ?? null
   const scroll = useChatScroll({
     ready: openState === 'open',
     order, firstSeq, lastKey, running, loadingOlder, hasMore, chatScroll, loadOlder, loadThrough,
     lastIsUser: lastKey !== null && nodeStore.get(lastKey)?.kind === 'user',
-    steeringId: pendingSteering.at(-1)?.id ?? null,
+    steeringId,
     submissionId: visibleSubmissions.at(-1)?.requestId ?? null,
     loadedTurns: turnNavigationItems,
   })

packages/client/ui-chat/src/client/chat/use-chat-scroll.ts

@@ -53,8 +53,10 @@ export function useChatScroll(input: ChatScrollInput): ChatScrollState {
     const current = content.current.input
     const previous = content.current.applied
     const ownInput = (current.lastIsUser && current.lastKey !== previous?.lastKey)
-      || (current.steeringId !== null && current.steeringId !== previous?.steeringId)
-      || (current.submissionId !== null && current.submissionId !== previous?.submissionId)
+      || (current.steeringId !== null && current.steeringId !== previous?.steeringId
+        && current.steeringId !== previous?.submissionId)
+      || (current.submissionId !== null && current.submissionId !== previous?.submissionId
+        && current.submissionId !== previous?.steeringId)
     if (reading.pending && !ownInput) return
     content.current.applied = current
     if (current.ready && !content.current.opened) {

packages/client/ui-chat/src/client/conversation-nodes/assistant.ts

@@ -34,7 +34,6 @@ interface AssistantState {
   readonly firstVisibleSeq: number | undefined
   readonly firstVisibleTime: number | undefined
   readonly firstTokenTime: number | undefined
-  readonly hidden: boolean
   readonly final: ConversationMatch | undefined
   readonly usage: unknown
 }
@@ -48,7 +47,6 @@ function initialState(turn: number, step: number): AssistantState {
     firstVisibleSeq: undefined,
     firstVisibleTime: undefined,
     firstTokenTime: undefined,
-    hidden: false,
     final: undefined,
     usage: undefined,
   }
@@ -85,7 +83,6 @@ function resetForRetry(state: AssistantState): AssistantState {
   return {
     ...initialState(state.turn, state.step),
     firstTokenTime: state.firstTokenTime,
-    hidden: true,
   }
 }
 
@@ -151,7 +148,6 @@ function updateChunk(
     ...state,
     blocks,
     visibleBlocks,
-    hidden: visibleBlocks > 0 ? false : state.hidden,
     ...visibleBlocks > 0 && state.firstVisibleSeq === undefined
       ? { firstVisibleSeq: seq, firstVisibleTime: time }
       : {},
@@ -171,7 +167,6 @@ function settleMessage(
     ...state,
     blocks,
     visibleBlocks: countVisibleBlocks(blocks),
-    hidden: false,
     final: match,
     usage: event.data.usage,
   }
@@ -289,7 +284,7 @@ function publishedAssistantData(
   return location?.kind === 'step' ? location.step.data.get('assistant-step') : undefined
 }
 
-/** Per-step Assistant streaming/final/interruption Definition. */
+/** Per-step Assistant lifecycle; materialized keys survive cleared stream content as hidden Nodes. */
 export const assistantDefinition: ConversationNodeDefinition<AssistantState> = {
   kind: 'assistant-step',
   target: 'chat',
@@ -337,16 +332,15 @@ export const assistantDefinition: ConversationNodeDefinition<AssistantState> = {
     }
   },
   buildViewNode: (context) => {
+    const current = context.current.get('chat')
     const state = context.state ?? fallbackState(context)
-    if (state === undefined) return null
     const data = publishedAssistantData(context)
-    if (data === undefined) return null
+    if (state === undefined || data === undefined) {
+      return current == null ? null : { ...current, visibility: 'hidden' }
+    }
     const settled = data.finalNode
     const visible = settled === undefined ? state.visibleBlocks > 0 : hasVisibleContent(data.blocks)
-    if (settled === undefined && !visible) {
-      const current = context.current.get('chat')
-      if (!state.hidden || current === undefined || current === null) return null
-    }
+    if (settled === undefined && !visible && current == null) return null
     const anchorSeq = settled?.seq ?? state.firstVisibleSeq ?? context.matches[0]?.event.seq ?? 0
     return chatNode(context, 'assistant-step', anchorSeq, data, {
       visibility: settled?.interrupted === true || visible ? 'visible' : 'hidden',

packages/client/ui-chat/tests/chat-view.client.spec.tsx

@@ -1573,7 +1573,27 @@ describe('ChatView', () => {
     expect(view.getAllByText('即发即显')).toHaveLength(1)
   })
 
-  it('renders a local steer echo as pending steering before Host image admission completes', () => {
+  it('does not pull the reader back to the tail when a local steer becomes Host-pending', () => {
+    const h = makeHarness({ nodes: [assistant(1, 'working')] }, { running: true })
+    const view = render(<h.ChatView {...h.props} />)
+    const scroller = view.container.querySelector<HTMLElement>('[class*="scroll"]')!
+    installScrollMetrics(scroller, 1_000, 300)
+    act(() => { h.setSession({ pendingSubmissions: [{
+      requestId: 'req-steer' as never, placement: 'steering', time: 5_000, text: 'continue here', attachments: [],
+    }] }) })
+    expect(scroller.scrollTop).toBe(700)
+    readerScroll(scroller, 100)
+
+    act(() => { h.setSession({ testInbox: { 'next-turn': [], 'next-step': [{
+      id: 'steer-occurrence' as never, role: 'user', source: { kind: 'user', rpcId: 'req-steer' as never },
+      content: [{ type: 'text', text: 'continue here' }],
+    }] } }) })
+    expect(view.getAllByText('continue here')).toHaveLength(1)
+    expect(scroller.scrollTop).toBe(100)
+    expect(view.getByLabelText('回到底部')).toBeTruthy()
+  })
+
+  it('retains the same local steer bubble through Host acceptance and claim until its durable node arrives', () => {
     const h = makeHarness(
       { nodes: [assistant(1, 'working')] },
       {
@@ -1604,8 +1624,20 @@ describe('ChatView', () => {
       })
     })
     expect(view.getAllByText('带图纠偏')).toHaveLength(1)
+    expect(view.container.querySelector('[data-submission-echo]')).toBe(local)
+    expect(view.container.querySelectorAll('[data-pending-steering]')).toHaveLength(1)
+
+    act(() => { h.setSession({ testInbox: { 'next-turn': [], 'next-step': [] } }) })
+    expect(view.container.querySelector('[data-submission-echo]')).toBe(local)
+    expect(view.getAllByText('带图纠偏')).toHaveLength(1)
+
+    act(() => { h.setChat({ nodes: [assistant(1, 'working'), {
+      ...steering(2, '带图纠偏', 1), source: { kind: 'user', rpcId: 'req-steer' as never },
+    }] }) })
+    expect(view.getAllByText('带图纠偏')).toHaveLength(1)
     expect(view.container.querySelector('[data-submission-echo]')).toBeNull()
-    expect(view.container.querySelector('[data-pending-steering]')).not.toBeNull()
+    act(() => { h.setSession({ pendingSubmissions: [] }) })
+    expect(view.getAllByText('带图纠偏')).toHaveLength(1)
   })
 
   it('keeps a queued echo out of the Chat flow before and after Host admission', () => {

packages/client/ui-chat/tests/conversation-node-definitions.client.spec.ts

@@ -993,6 +993,73 @@ describe('built-in conversation node Definitions', () => {
     })
   })
 
+  it.each([
+    { outcome: 'attempt', startLoaded: true },
+    { outcome: 'attempt', startLoaded: false },
+    { outcome: 'abandoned', startLoaded: true },
+    { outcome: 'abandoned', startLoaded: false },
+  ])('retains the Assistant key after $outcome retirement (startLoaded=$startLoaded)', ({ outcome, startLoaded }) => {
+    const attemptId = LlmAttemptId('retired-chat-attempt')
+    const chunk = { type: 'text-delta' as const, index: 0, text: 'Discarded reply' }
+    const stream = new AssistantStreamAccumulator()
+    stream.push({ time: 1_030, chunk })
+    const value = assembler([
+      at(1, 'turn/start', { turn: 1 }),
+      ...startLoaded ? [at(2, 'step/start', { turn: 1, step: 1 })] : [],
+    ], !startLoaded)
+    value.append({
+      type: 'transient',
+      event: {
+        type: 'assistant/live-chunk', seq: 2.5, time: 1_030,
+        data: { attemptId, turn: 1, step: 1, chunk },
+      },
+    })
+    // The Step end can publish while the matching Assistant end frame still holds its settlement.
+    if (!startLoaded) value.append(at(4, 'step/end', { turn: 1, step: 1 }))
+    value.flush()
+    const visible = node(snapshot(value), 'assistant-step')
+    expect(visible?.visibility).toBe('visible')
+
+    if (outcome === 'attempt') {
+      const event = at(3, 'assistant/attempt', { turn: 1, step: 1, stream: stream.snapshot() }).event
+      if (event.type !== 'assistant/attempt') throw new Error('expected Assistant attempt')
+      value.settleAssistant(attemptId, { type: 'event', event })
+    } else value.settleAssistant(attemptId)
+    expect(() => value.flush()).not.toThrow()
+    const hidden = node(snapshot(value), 'assistant-step')
+    expect(hidden?.key).toBe(visible?.key)
+    expect(hidden?.visibility).toBe('hidden')
+    expect(snapshot(value).order).not.toContain(hidden?.key)
+
+    if (!startLoaded) {
+      value.append(at(5, 'turn/end', { turn: 1, reason: { kind: 'completed' } }))
+      expect(() => value.flush()).not.toThrow()
+      expect(node(snapshot(value), 'assistant-step')?.visibility).toBe('hidden')
+      return
+    }
+    value.append(at(4, 'llm/retry', {
+      retryId: 'retired-chat-retry', turn: 1, step: 1, provider: 'fake', mode: 'normal',
+      policyKey: 'fake-normal', retry: 1, maxRetries: 2, delayMs: 10,
+      failure: { code: 'TRANSPORT', message: 'temporary' },
+    }))
+    expect(() => value.flush()).not.toThrow()
+    value.append({
+      type: 'transient',
+      event: {
+        type: 'assistant/live-chunk', seq: 4.5, time: 1_050,
+        data: {
+          attemptId: LlmAttemptId('replacement-chat-attempt'), turn: 1, step: 1,
+          chunk: { type: 'text-delta', index: 0, text: 'Replacement reply' },
+        },
+      },
+    })
+    value.flush()
+    const replacement = node(snapshot(value), 'assistant-step')
+    expect(replacement?.key).toBe(visible?.key)
+    expect(replacement?.visibility).toBe('visible')
+    expect(replacement?.data).toMatchObject({ blocks: [{ kind: 'text', text: 'Replacement reply' }] })
+  })
+
   it('omits first-token metrics after live settlement and after reopening the same history', () => {
     const attemptId = LlmAttemptId('settled-chat-timing')
     const starts = [

snapshots/web/live-interactions/retry-expanded.expected.md

@@ -8,11 +8,11 @@
     - tab "Trajectory"
 - text: Reply with a one-sentence description of event sourcing, then stop. {{clock}}
 - button "Copy"
-- button "Thought for a while" [expanded]
-- button "Context injection runtime-context"
+- status: Worked
+- button "Took {{duration}}" [expanded]
 - group:
   - status: Retried model request (1/5) · {{duration}}
-- button "Think"
+- button "Analysis completed"
 - paragraph: Event sourcing is a pattern where all changes to an application's state are stored as an immutable, append-only sequence of events, rather than persisting only the current state, enabling full auditability, temporal queries, and event-driven architectures.
 - button "Copy"
 - button "Good response"

snapshots/web/live-interactions/retry.expected.md

@@ -8,7 +8,8 @@
     - tab "Trajectory"
 - text: Reply with a one-sentence description of event sourcing, then stop. {{clock}}
 - button "Copy"
-- button "Thought for a while"
+- status: Worked
+- button "Took {{duration}}"
 - paragraph: Event sourcing is a pattern where all changes to an application's state are stored as an immutable, append-only sequence of events, rather than persisting only the current state, enabling full auditability, temporal queries, and event-driven architectures.
 - button "Copy"
 - button "Good response"