fix(client): keep trajectory history on the session seam

packages/client/ui-trajectory/src/client/TrajectoryView.tsx

@@ -1,12 +1,9 @@
 /** Trajectory view: compact summary over a turn-aware event ledger. */
 
-import { useEffect, useMemo, useState, useSyncExternalStore } from 'react'
+import { useEffect, useMemo, useRef, useState } from 'react'
 import type { ConvViewProps } from '@deepseek-ai/dsh-client-ui-conversation/client'
 import type {
-  AssistantMessageNode, ConversationContext, SessionHistory,
-} from '@deepseek-ai/dsh-client-runtime/client'
-import {
-  inspectRequests, projectConversationHistory,
+  AssistantMessageNode, ConversationContext, RequestView,
 } from '@deepseek-ai/dsh-client-runtime/client'
 import { deriveTrajectoryContextBranches } from './context-branches.ts'
 import {
@@ -19,10 +16,11 @@ import { deriveTrajectoryLayout } from './layout.ts'
 import css from './views.module.css'
 
 const EMPTY_IDS: ReadonlySet<number> = new Set()
+const EMPTY_REQUESTS: readonly RequestView[] = []
 
-/** Raw session-history source needed by the event-complete trajectory view. */
+/** Session-history paging needed by the event-complete trajectory view. */
 export interface TrajectoryViewInjected {
-  history: SessionHistory
+  loadAllHistory: () => Promise<void>
 }
 
 interface UsageLike {
@@ -69,47 +67,29 @@ function addUsage(
   }
 }
 
-export function TrajectoryView({ useSession, history }: ConvViewProps & TrajectoryViewInjected) {
+export function TrajectoryView({ useSession, loadAllHistory }: ConvViewProps & TrajectoryViewInjected) {
   const [collapsedTurns, setCollapsedTurns] = useState<ReadonlySet<number>>(EMPTY_IDS)
   const [collapsedAssistants, setCollapsedAssistants] =
     useState<ReadonlySet<number>>(EMPTY_IDS)
   const nodes = useSession(s => s.nodes)
+  const inspection = useSession(s => s.inspection)
+  const hasMore = useSession(s => s.hasMore)
+  const openState = useSession(s => s.openState)
   const partial = useSession(s => s.partial)
   const runningCalls = useSession(s => s.runningCalls)
   const codeDispatches = useSession(s => s.codeDispatches)
-  const subscribeHistory = useMemo(
-    () => (listener: () => void) => history.subscribe(listener),
-    [history],
-  )
-  const getHistorySnapshot = useMemo(
-    () => () => history.getSnapshot(),
-    [history],
-  )
-  const historySnapshot = useSyncExternalStore(
-    subscribeHistory,
-    getHistorySnapshot,
-    getHistorySnapshot,
-  )
+  const loadAllHistoryRef = useRef(loadAllHistory)
+  loadAllHistoryRef.current = loadAllHistory
   useEffect(() => {
-    if (historySnapshot.openState === 'open' && historySnapshot.hasMore) {
-      void history.loadAll()
-    }
-  }, [history, historySnapshot.hasMore, historySnapshot.openState])
-  const projectedHistory = useMemo(
-    () => projectConversationHistory(historySnapshot.entries),
-    [historySnapshot.entries],
-  )
-  const requestInspection = useMemo(
-    () => inspectRequests(historySnapshot.entries),
-    [historySnapshot.entries],
-  )
-  const requests = requestInspection.requests
-  const callSchemas = requestInspection.callSchemas
+    if (openState === 'open' && hasMore) void loadAllHistoryRef.current()
+  }, [hasMore, openState])
+  const requests = inspection?.requests ?? EMPTY_REQUESTS
+  const callSchemas = inspection?.callSchemas
   const contexts = useMemo<readonly ConversationContext[]>(
-    () => projectedHistory.contexts.length === 0
+    () => inspection === undefined || inspection.contexts.length === 0
       ? [{ id: 0, nodes }]
-      : projectedHistory.contexts,
-    [nodes, projectedHistory.contexts],
+      : inspection.contexts,
+    [inspection, nodes],
   )
   const branches = useMemo(
     () => deriveTrajectoryContextBranches(contexts),
@@ -117,9 +97,9 @@ export function TrajectoryView({ useSession, history }: ConvViewProps & Trajecto
   )
   const currentBranch = branches.at(-1)
   if (currentBranch === undefined) throw new Error('trajectory branch projection must not be empty')
-  const selectedNodes = projectedHistory.eventNodes.length === 0
+  const selectedNodes = inspection === undefined || inspection.eventNodes.length === 0
     ? nodes
-    : projectedHistory.eventNodes
+    : inspection.eventNodes
   const globalRequestNumbers = useMemo<readonly TrajectoryRequestNumber[]>(() => {
     const assistantsByStep = new Map<string, AssistantMessageNode>()
     for (const context of contexts) {
@@ -256,7 +236,7 @@ export function TrajectoryView({ useSession, history }: ConvViewProps & Trajecto
       partial,
       runningCalls,
       requests,
-      callSchemas,
+      ...(callSchemas === undefined ? {} : { callSchemas }),
       codeDispatches,
     }),
     [

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

@@ -36,7 +36,7 @@ export function apply(ctx: Context): void {
       if (session === undefined) {
         throw new Error(`ui-trajectory: session "${sessionId}" resolved no binding`)
       }
-      return { history: session.history }
+      return { loadAllHistory: () => session.loadAllHistory() }
     },
   }, TrajectoryView)
   ctx.slots.register(

packages/client/ui-trajectory/tests/client-bundle.spec.ts

@@ -60,7 +60,7 @@ describe('tsdown client artifact', () => {
     const { handoff, surface } = await loadArtifact()
     expect(handoff.id).toBe(PLUGIN_ID)
     expect(surface.apply).toBeTypeOf('function')
-    expect(surface.inject).toEqual(['slots', 'conversation'])
+    expect(surface.inject).toEqual(['slots', 'conversation', 'sessions'])
   })
 
   it.skipIf(code === undefined)('mounted as an object plugin, apply registers both view tabs on the real ring', async () => {
@@ -72,10 +72,10 @@ describe('tsdown client artifact', () => {
       name: 'root',
       children: { 'conversation.view': { kind: 'list', scope: 'session' } },
     }, (_p: { renderSlot?: unknown }) => null)
-    // The plugin injects 'conversation' as an ordering edge (the declaring
-    // plugin provides it after declaring the ring); the bench declares the
-    // ring itself, so a stub satisfies the wait.
+    // The plugin injects 'conversation' as an ordering edge and 'sessions'
+    // for its per-session history callback; this bench supplies both.
     ctx.provide('conversation', {})
+    ctx.provide('sessions', {})
     const fiber = ctx.plugin(surface as { apply: (ctx: Context) => void })
     await fiber.await()
     expect(slots.entries('conversation.view').map(e => e.options.id)).toEqual(['trajectory', 'waterfall'])

packages/client/ui-trajectory/tests/views.spec.tsx

@@ -16,8 +16,7 @@ import { createSnapshotStore } from '@deepseek-ai/dsh-client-runtime/client'
 import type { UseSession } from '@deepseek-ai/dsh-client-web-react'
 import { SlotsService } from '@deepseek-ai/dsh-client-runtime/client'
 import type {
-  ConversationSnapshot, SessionHistory, SessionHistorySnapshot, SessionId,
-  SessionListState, WorkspaceListState,
+  ConversationSnapshot, SessionId, SessionListState, WorkspaceListState,
 } from '@deepseek-ai/dsh-client-runtime/client'
 import type { ConvViewProps, ViewTab } from '@deepseek-ai/dsh-client-ui-conversation/client'
 // Export discipline: packages/client/AGENTS.md.
@@ -83,42 +82,11 @@ function standaloneProps(nodes: ConversationSnapshot['nodes']): ConvViewProps {
   } as unknown as ConvViewProps
 }
 
-function emptyHistory(): SessionHistory {
-  const store = createSnapshotStore<SessionHistorySnapshot>({
-    sessionId: SID,
-    entries: [],
-    baseSeq: 0,
-    openState: 'open',
-    openError: null,
-    hasMore: false,
-    loadingOlder: false,
-  })
-  return {
-    getSnapshot: () => store.getSnapshot(),
-    subscribe: listener => store.subscribe(listener),
-    loadAll: () => Promise.resolve(),
-  }
-}
-
 /** Real-stack bench: root Context + real SlotsService ring + the plugin fiber. */
 async function bench() {
   const ctx = new Context()
   const slots = new SlotsService(ctx)
   const loadAllHistory = vi.fn(() => Promise.resolve())
-  const historyStore = createSnapshotStore<SessionHistorySnapshot>({
-    sessionId: SID,
-    entries: [],
-    baseSeq: 0,
-    openState: 'open',
-    openError: null,
-    hasMore: true,
-    loadingOlder: false,
-  })
-  const history: SessionHistory = {
-    getSnapshot: () => historyStore.getSnapshot(),
-    subscribe: listener => historyStore.subscribe(listener),
-    loadAll: loadAllHistory,
-  }
   // The conversation entry's role: declare the ring, then seed the chat entry.
   slots.register({
     name: 'root',
@@ -132,7 +100,7 @@ async function bench() {
   ctx.provide('conversation', {})
   ctx.provide('sessions', {
     binding: (sessionId: SessionId) => sessionId === SID
-      ? { session: { history } }
+      ? { session: { loadAllHistory } }
       : undefined,
   })
   const fiber = ctx.plugin({ inject: [...inject], apply })
@@ -295,7 +263,7 @@ describe('span derivation', () => {
     expect(container.firstChild).toBeNull()
     render(createElement(
       TrajectoryView,
-      { ...standaloneProps([]), history: emptyHistory() },
+      { ...standaloneProps([]), loadAllHistory: () => Promise.resolve() },
     ))
     expect(screen.getByRole('toolbar', { name: 'Trajectory toolbar' })).toBeTruthy()
     expect(screen.queryByRole('row')).toBeNull()