feat(client-runtime): add target-owned conversation snapshots

packages/client/runtime/src/client/contract/conversation.ts

@@ -110,6 +110,17 @@ export interface ConversationViewNode {
   readonly data: unknown
 }
 
+/** Merge-extensible immutable snapshots published by registered view targets. */
+export interface ConversationViewSnapshotMap {}
+
+/** Stable reader over the latest snapshot of every registered view target. */
+export interface ConversationViewSnapshotStore {
+  /** @param target - registered view target. @returns its current snapshot. */
+  get<Target extends keyof ConversationViewSnapshotMap & string>(
+    target: Target,
+  ): ConversationViewSnapshotMap[Target] | undefined
+}
+
 /** Final Chat render unit produced directly by a business Definition. */
 export interface ChatConversationViewNode extends ConversationViewNode {
   readonly target: 'chat'
@@ -159,6 +170,8 @@ export type ConversationLocationDataScope = 'step' | 'turn'
 /** One independently registered business Event-to-Node state machine. */
 export interface ConversationNodeDefinition<State = unknown> {
   readonly kind: string
+  /** Sole view target owned by this Definition; omitted for state-only Contexts. */
+  readonly target?: string
   /**
    * Extract this Definition's stable business identity from one event.
    * @param event - raw Session event; no Context or history access is available.
@@ -207,15 +220,11 @@ export interface ConversationNodeDefinition<State = unknown> {
     scope: ConversationLocationDataScope,
   ): ConversationLocationData | null
   /**
-   * Materialize one final Node for a registered view target.
+   * Materialize one final Node for this Definition's declared view target.
    * @param context - latest complete Context.
-   * @param target - registered view target such as `chat`.
    * @returns final Node, or null when this Context is not currently visible.
    */
-  buildViewNode(
-    context: ConversationNodeContext<State>,
-    target: string,
-  ): ConversationViewNode | null
+  buildViewNode?(context: ConversationNodeContext<State>): ConversationViewNode | null
 }
 
 /** Reference-stable Turn/Step facts published beside view Nodes. */

packages/client/runtime/src/client/conversation/event-registry.ts

@@ -17,6 +17,7 @@ export class ConversationEventRegistry extends ConversationDefinitionRegistry<Co
    * @returns idempotent disposer.
    */
   register(definition: ConversationNodeDefinition): () => void {
+    assertDefinitionTarget(definition)
     return this.registerDefinition(
       definition.kind,
       definition,
@@ -31,6 +32,9 @@ export class ConversationEventRegistry extends ConversationDefinitionRegistry<Co
    * @returns idempotent disposer.
    */
   registerFallback(definition: ConversationNodeDefinition): () => void {
+    assertDefinitionTarget(definition)
+    const target = definition.target
+    if (target === undefined) throw new Error('conversation fallback Definition must declare a target')
     if (this.fallback !== undefined) throw new Error('conversation fallback Definition is already registered')
     const owner = this.ctx
     const dispose = owner.effect(() => {
@@ -52,5 +56,12 @@ export class ConversationEventRegistry extends ConversationDefinitionRegistry<Co
   fallbackEntry(): ConversationNodeDefinition | undefined {
     return this.fallback
   }
-
+}
+
+function assertDefinitionTarget(definition: ConversationNodeDefinition): void {
+  if ((definition.target === undefined) !== (definition.buildViewNode === undefined)) {
+    throw new Error(
+      `conversation Definition "${definition.kind}" must declare target and buildViewNode together`,
+    )
+  }
 }

packages/client/runtime/src/client/index.ts

@@ -6,7 +6,6 @@ import type { MaybeSnapshotSelectorHook, SnapshotSelectorHook } from '@deepseek-
 import { SlotsService } from './slots.ts'
 import { SessionsService } from './sessions/service.ts'
 import type { SessionListState } from './sessions/service.ts'
-import { SessionHistoryService } from './session-history/service.ts'
 import { WorkspacesService } from './workspaces/service.ts'
 import type { ConversationSnapshot } from './sessions/conversation.ts'
 import type { UseProjection } from './sessions/projection-store.ts'
@@ -28,12 +27,12 @@ export type {
   ConversationLocation, ConversationMatch, ConversationMatchResult,
   ConversationNodeContext, ConversationNodeDefinition, ConversationPreviousContext,
   ConversationPublication, ConversationTimelineSnapshot, ConversationTurnDataMap, ConversationViewBuilder,
-  ConversationViewDefinition, ConversationViewNode, StepLocation, TurnLocation,
+  ConversationViewDefinition, ConversationViewNode, ConversationViewSnapshotMap,
+  ConversationViewSnapshotStore, StepLocation, TurnLocation,
 } from './contract/conversation.ts'
 export type { ConversationRuntime } from './sessions/conversation-assembler.ts'
 export type { RootOwnerProps } from './slots.ts'
 export { SessionCreateError, SessionsService, scopeOf, workspaceTitleOf } from './sessions/service.ts'
-export { SessionHistoryService } from './session-history/service.ts'
 export { indexSubagentDescendants } from './sessions/subagent-lineage.ts'
 export type { SubagentDescendantSummary } from './sessions/subagent-lineage.ts'
 // The provide channel is shared with the client test runtime (one
@@ -48,9 +47,6 @@ export type { SettingsScope, SettingsScopeSnapshot, SettingsScopeSpec } from './
 export { resolveWorkspacePath } from './workspaces/path.ts'
 export type { Session } from './sessions/session.ts'
 export type { ISession, ProjectionsFace, SessionFace } from './contract/session.ts'
-export type {
-  ISessionHistory, SessionHistoryFace, SessionHistorySnapshot,
-} from './contract/session-history.ts'
 export type { AgentContext, ISessions } from './contract/sessions.ts'
 export type { IWorkspaces } from './contract/workspaces.ts'
 export type {
@@ -76,7 +72,9 @@ export type {
   LegacyConversationSlice, PartialAssistant, RunningToolCall,
   SteeringMessageNode, TodoItem, ToolCallBlock, ToolResultNode, TurnErrorNode, UnknownSurfaceNode, UserMessageNode,
 } from './sessions/conversation.ts'
-export { EMPTY_CHAT_SNAPSHOT, toAssistantBlock, toAssistantBlocks } from './sessions/conversation.ts'
+export {
+  EMPTY_CHAT_SNAPSHOT, EMPTY_CONVERSATION_VIEWS, toAssistantBlock, toAssistantBlocks,
+} from './sessions/conversation.ts'
 export { emptyAssistantBlock } from './sessions/partial.ts'
 export { isTokenDelta } from './sessions/assistant-timing.ts'
 export { contextForm, contextProvenance } from './sessions/context-provenance.ts'
@@ -90,8 +88,6 @@ export type {
 export type {
   ConversationPromptSnapshot, RequestInspectionSnapshot, RequestPromptChange, RequestView,
 } from './sessions/request-inspection.ts'
-export type { ConversationHistoryProjection } from './session-history/history-fold.ts'
-export type { SessionHistoryInspection } from './sessions/history.ts'
 export { PendingWait } from './sessions/pending.ts'
 export type {
   PendingInteraction, PendingInteractionStatus, PendingKind, PendingPayloads,
@@ -211,8 +207,6 @@ declare module '@deepseek-ai/cordis' {
     conversationViews: import('./conversation/view-registry.ts').ConversationViewRegistry
     /** The outward face only; the concrete service stays inside the runtime. */
     sessions: import('./contract/sessions.ts').ISessions
-    /** Read-only history sources isolated from Chat sessions and workspace state. */
-    sessionHistory: import('./contract/session-history.ts').ISessionHistory
     /** The outward face only; the concrete service stays inside the runtime. */
     workspaces: import('./contract/workspaces.ts').IWorkspaces
   }
@@ -235,7 +229,6 @@ export function apply(ctx: Context): void {
   ctx.typert.contexts.registerClient('agent', {
     identity: candidate => sessions.scopeOf(candidate),
   })
-  const sessionHistory = new SessionHistoryService(ctx, connection.api)
   const workspaces = new WorkspacesService(ctx, connection.api, sessions)
   ctx.effect(
     () => workspaces.startInitialSelection(),
@@ -244,11 +237,6 @@ export function apply(ctx: Context): void {
   const loop = connection.start({
     onMuxEnvelope: (envelope) => {
       sessions.handleMuxEnvelope(envelope)
-      try {
-        sessionHistory.handleMuxEnvelope(envelope)
-      } catch (error) {
-        console.error('[web-runtime] history frame routing failed:', error)
-      }
     },
     onHostEnvelope: (envelope) => {
       sessions.handleHostEnvelope(envelope)
@@ -264,21 +252,11 @@ export function apply(ctx: Context): void {
       else if (frame.type === 'host/settings-changed') ctx.emit('settings/changed', frame.ns)
       else if (frame.type === 'host/credentials-changed') ctx.emit('credentials/changed', frame.ref)
       else if (frame.type === 'host/models-changed') ctx.emit('models/changed')
-      try {
-        sessionHistory.handleHostEnvelope(envelope)
-      } catch (error) {
-        console.error('[web-runtime] history host-frame routing failed:', error)
-      }
     },
     onConnected: () => {
       sessions.handleConnected()
       workspaces.handleConnected()
       ctx.emit('connection/reset')
-      try {
-        sessionHistory.handleConnected()
-      } catch (error) {
-        console.error('[web-runtime] history reconnect failed:', error)
-      }
     },
     onStateChange: (state) => {
       // Generation death fires before any next-generation frame can arrive
@@ -286,11 +264,6 @@ export function apply(ctx: Context): void {
       // the only safe moment to drop generation-scoped interaction state.
       if (state === 'reconnecting') {
         sessions.handleDisconnected()
-        try {
-          sessionHistory.handleDisconnected()
-        } catch (error) {
-          console.error('[web-runtime] history disconnect failed:', error)
-        }
       }
     },
   })

packages/client/runtime/src/client/sessions/conversation-assembler.ts

@@ -2,7 +2,8 @@ import type {
   ConversationContextReader, ConversationEventInput, ConversationLocationData, ConversationMatch,
   ConversationNodeContext, ConversationNodeDefinition, ConversationPreviousContext,
   ConversationLocationDataScope, ConversationPublication, ConversationViewBuilder,
-  ConversationViewDefinition, ConversationViewNode,
+  ConversationViewDefinition, ConversationViewNode, ConversationViewSnapshotMap,
+  ConversationViewSnapshotStore,
 } from '../contract/conversation.ts'
 import { conversationContextKey } from '../contract/conversation.ts'
 import {
@@ -133,7 +134,7 @@ export interface ConversationViewDefinitions {
  * Session-owned incremental engine that assembles business Contexts from a
  * contiguous Event window and materializes registered view snapshots.
  */
-export class ConversationNodeAssembler {
+export class ConversationNodeAssembler implements ConversationViewSnapshotStore {
   private readonly contexts = new Map<string, InternalContext>()
   private readonly contextsByKind = new Map<string, InternalContext[]>()
   private readonly contextsBySeq = new Map<number, Set<InternalContext>>()
@@ -266,11 +267,11 @@ export class ConversationNodeAssembler {
       const allByTarget = new Map<string, ConversationViewNode[]>()
       for (const target of this.views.keys()) allByTarget.set(target, [])
       for (const context of this.contexts.values()) {
-        for (const target of this.views.keys()) {
-          const node = this.buildNode(context, target)
-          context.current.set(target, node)
-          if (node !== null) allByTarget.get(target)?.push(node)
-        }
+        const target = context.definition.target
+        if (target === undefined || !this.views.has(target)) continue
+        const node = this.buildNode(context, target)
+        context.current.set(target, node)
+        if (node !== null) allByTarget.get(target)?.push(node)
       }
       for (const view of this.views.values()) {
         view.snapshot = view.builder.replace({
@@ -288,17 +289,17 @@ export class ConversationNodeAssembler {
     for (const target of this.views.keys()) upsertsByTarget.set(target, [])
     if (this.applyDirtyLocationData()) this.timelineDirty = true
     for (const context of this.dirty) {
-      for (const target of this.views.keys()) {
-        const previous = context.current.get(target) ?? null
-        const node = this.buildNode(context, target)
-        if (node === null && previous !== null) {
-          throw new Error(
-            `conversation Definition "${context.kind}" withdrew materialized target "${target}"; return the same key with hidden visibility instead`,
-          )
-        }
-        context.current.set(target, node)
-        if (node !== null) upsertsByTarget.get(target)?.push(node)
+      const target = context.definition.target
+      if (target === undefined || !this.views.has(target)) continue
+      const previous = context.current.get(target) ?? null
+      const node = this.buildNode(context, target)
+      if (node === null && previous !== null) {
+        throw new Error(
+          `conversation Definition "${context.kind}" withdrew materialized target "${target}"; return the same key with hidden visibility instead`,
+        )
       }
+      context.current.set(target, node)
+      if (node !== null) upsertsByTarget.get(target)?.push(node)
     }
     this.dirty.clear()
     const timelineDirty = this.timelineDirty
@@ -323,6 +324,12 @@ export class ConversationNodeAssembler {
     return this.views.get(target)?.snapshot
   }
 
+  get<Target extends keyof ConversationViewSnapshotMap & string>(
+    target: Target,
+  ): ConversationViewSnapshotMap[Target] | undefined {
+    return this.snapshot(target) as ConversationViewSnapshotMap[Target] | undefined
+  }
+
   private sortedInputs(): ConversationEventInput[] {
     return [...this.inputs.values()].sort((left, right) => left.event.seq - right.event.seq)
   }
@@ -358,18 +365,19 @@ export class ConversationNodeAssembler {
       role: ConversationMatch['role'],
     ) => ConversationPublication,
   ): ConversationPublication {
-    let matched = false
+    const matchedTargets = new Set<string>()
     let publication: ConversationPublication = 'none'
     for (const definition of this.eventDefinitions.entries()) {
       const result = definition.match(input.event)
       if (result === null) continue
-      matched = true
+      if (definition.target !== undefined) matchedTargets.add(definition.target)
       publication = maximumPublication(publication, accept(definition, result.id, result.role))
     }
-    if (!matched) {
-      const fallback = this.eventDefinitions.fallbackEntry()
-      const result = fallback?.match(input.event) ?? null
-      if (fallback !== undefined && result !== null) {
+    const fallback = this.eventDefinitions.fallbackEntry()
+    const target = fallback?.target
+    if (fallback !== undefined && target !== undefined && !matchedTargets.has(target)) {
+      const result = fallback.match(input.event)
+      if (result !== null) {
         publication = maximumPublication(publication, accept(fallback, result.id, result.role))
       }
     }
@@ -697,7 +705,8 @@ export class ConversationNodeAssembler {
   }
 
   private buildNode(context: InternalContext, target: string): ConversationViewNode | null {
-    const node = context.definition.buildViewNode(contextSnapshot(context), target)
+    if (context.definition.target !== target || context.definition.buildViewNode === undefined) return null
+    const node = context.definition.buildViewNode(contextSnapshot(context))
     if (node === null) return null
     if (node.key !== context.key) {
       throw new Error(`conversation Definition "${context.kind}" returned unstable key "${node.key}"; expected "${context.key}"`)

packages/client/runtime/src/client/sessions/conversation.ts

@@ -17,7 +17,7 @@ import type {
 import type { PendingInteraction } from './pending.ts'
 import type { ContextProvenanceView, KnownContextForm } from './context-provenance.ts'
 import type {
-  ChatConversationViewNode, ConversationTimelineSnapshot,
+  ChatConversationViewNode, ConversationTimelineSnapshot, ConversationViewSnapshotStore,
 } from '../contract/conversation.ts'
 export type { TodoItem }
 
@@ -384,6 +384,11 @@ export interface ChatSnapshot {
 const EMPTY_LIST: readonly never[] = []
 const EMPTY_TIMELINE: ConversationTimelineSnapshot = { turnOrder: EMPTY_LIST, turns: new Map() }
 
+/** Empty target store used by fixtures and Sessions without registered views. */
+export const EMPTY_CONVERSATION_VIEWS: ConversationViewSnapshotStore = {
+  get: () => undefined,
+}
+
 /** Empty Chat target used before a view builder is registered. */
 export const EMPTY_CHAT_SNAPSHOT: ChatSnapshot = {
   order: EMPTY_LIST,
@@ -408,6 +413,8 @@ export const EMPTY_CHAT_SNAPSHOT: ChatSnapshot = {
 /** The immutable snapshot contract Session hands to uSES (see the web client architecture RFC). */
 export interface ConversationSnapshot {
   sessionId: SessionId
+  /** Registered target snapshots assembled from Session events. */
+  views: ConversationViewSnapshotStore
   /** Final Chat target assembled from independently registered business Definitions. */
   chat: ChatSnapshot
   /** Legacy top-level compatibility field mirrored from the registered Chat Definitions. */

packages/client/runtime/src/client/sessions/session.ts

@@ -727,6 +727,7 @@ export class Session implements SessionFace {
     const legacy = chat.legacy
     return {
       sessionId: this.sessionId,
+      views: this.conversation,
       chat,
       nodes: legacy.nodes,
       turnTimings: legacy.turnTimings,

packages/client/runtime/tests/client-apply.spec.ts

@@ -126,6 +126,7 @@ describe('runtime client apply', () => {
     const rebuild = vi.spyOn(Session.prototype, 'rebuildConversationRegistry')
     const definition: ConversationNodeDefinition<null> = {
       kind: 'registry-probe',
+      target: 'chat',
       match: () => null,
       start: () => null,
       update: context => context.state,

packages/client/runtime/tests/conversation-assembler.spec.ts

@@ -30,10 +30,16 @@ interface TestSnapshot {
 }
 
 class TestEventDefinitions {
+  readonly definitions: readonly ConversationNodeDefinition[]
+  readonly fallback: ConversationNodeDefinition | undefined
+
   constructor(
-    readonly definitions: readonly ConversationNodeDefinition[],
-    readonly fallback?: ConversationNodeDefinition,
-  ) {}
+    definitions: readonly ConversationNodeDefinition[],
+    fallback?: ConversationNodeDefinition,
+  ) {
+    this.definitions = definitions.map(asChatDefinition)
+    this.fallback = fallback === undefined ? undefined : asChatDefinition(fallback)
+  }
 
   entries(): readonly ConversationNodeDefinition[] {
     return this.definitions
@@ -44,6 +50,12 @@ class TestEventDefinitions {
   }
 }
 
+function asChatDefinition(definition: ConversationNodeDefinition): ConversationNodeDefinition {
+  return definition.buildViewNode === undefined || definition.target !== undefined
+    ? definition
+    : { ...definition, target: 'chat' }
+}
+
 class TestViewDefinitions {
   constructor(readonly definitions: readonly ConversationViewDefinition[]) {}
 
@@ -93,7 +105,10 @@ function chatSnapshot(assembler: ConversationNodeAssembler): TestSnapshot | unde
   return assembler.snapshot('chat') as TestSnapshot | undefined
 }
 
-function node(context: Parameters<ConversationNodeDefinition['buildViewNode']>[0], data: unknown): ConversationViewNode {
+function node(
+  context: Parameters<NonNullable<ConversationNodeDefinition['buildViewNode']>>[0],
+  data: unknown,
+): ConversationViewNode {
   return {
     key: context.key,
     kind: context.kind,

packages/client/runtime/tests/conversation-registry.spec.ts

@@ -13,6 +13,7 @@ import { FakeApiClient, ok } from './fake-api.ts'
 function eventDefinition(kind: string): ConversationNodeDefinition<null> {
   return {
     kind,
+    target: 'chat',
     match: () => null,
     start: () => null,
     update: context => context.state,

packages/client/runtime/tests/session.spec.ts

@@ -123,12 +123,13 @@ function testViewDefinition(): ConversationViewDefinition<ChatConversationViewNo
 
 const TEST_EVENT_DEFINITION: ConversationNodeDefinition<TestEventState> = {
   kind: 'runtime-test-event',
+  target: 'chat',
   match: event => ({ id: String(event.seq), role: 'start' }),
   start: (_context, match) => ({ event: match.event, view: match.view }),
   update: context => context.state,
   publication: match => match.event.type === 'assistant/chunk' ? 'animation-frame' : 'immediate',
-  buildViewNode: (context, target) => {
-    if (target !== 'chat' || context.state === undefined || context.start === undefined) return null
+  buildViewNode: (context) => {
+    if (context.state === undefined || context.start === undefined) return null
     return {
       key: context.key,
       kind: 'runtime-test-event',