diff --git a/packages/acp/acp/tests/turns.spec.ts b/packages/acp/acp/tests/turns.spec.ts
index c42ef7e5c0..a4ae22080e 100644
--- a/packages/acp/acp/tests/turns.spec.ts
+++ b/packages/acp/acp/tests/turns.spec.ts
@@ -70,10 +70,13 @@ describe('ACP prompt lifecycle', () => {
     const sessionId = await newSession(harness)
     const agent = harness.ctx.agents.get(SessionId(sessionId))!
     let injected = false
-    harness.ctx.on('agent/inbox/enqueue', (subject) => {
-      if (subject === agent && !injected) {
+    harness.ctx.on('session/event', (session, event) => {
+      if (session === agent.session && event.type === 'agent/inbox/spliced'
+        && event.data.inserted.some(message => message.source.kind === 'user') && !injected) {
         injected = true
-        agent.inject(createUserMessage({ content: [{ type: 'text', text: 'context' }], source: { kind: 'plugin', plugin: 'test' } }))
+        queueMicrotask(() => {
+          agent.inject(createUserMessage({ content: [{ type: 'text', text: 'context' }], source: { kind: 'plugin', plugin: 'test' } }))
+        })
       }
     })
 
@@ -86,30 +89,44 @@ describe('ACP prompt lifecycle', () => {
     harness = await makeBridgeHarness({ script: ['hang'] })
     const sessionId = await newSession(harness)
     const agent = harness.ctx.agents.get(SessionId(sessionId))!
-    let inserted = false
-    harness.ctx.on('agent/inbox/enqueue', (subject, item) => {
-      if (subject !== agent || item.message.source.kind !== 'user' || inserted) return
-      inserted = true
-      const source = { kind: 'plugin', plugin: 'test' } as const
-      agent.session.append('turn/start', { turn: 1 })
-      agent.session.append('user/message', createUserMessage({
-        content: [{ type: 'text', text: 'autonomous work' }],
-        source,
-      }), { surfaceOp: 'append' })
-      agent.session.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
+    let autonomousStarted!: () => void
+    const started = new Promise<void>((resolve) => { autonomousStarted = resolve })
+    harness.ctx.on('session/event', (session, event) => {
+      if (session === agent.session && event.type === 'assistant/chunk') autonomousStarted()
     })
+    agent.followup(createUserMessage({
+      content: [{ type: 'text', text: 'autonomous work' }],
+      source: { kind: 'plugin', plugin: 'test' },
+    }))
+    await started
 
     let settled = false
     const prompt = harness.client.prompt({ sessionId, prompt: [{ type: 'text', text: 'go' }] })
       .finally(() => { settled = true })
     await vi.waitFor(() => {
-      expect(agent.session.events.filter(event => event.type === 'turn/start')).toHaveLength(2)
+      expect(agent.session.events.filter(event => event.type === 'agent/inbox/spliced'
+        && event.data.inserted.length > 0)).toHaveLength(2)
     })
     expect(settled).toBe(false)
     await harness.client.cancel({ sessionId })
     await expect(prompt).resolves.toEqual({ stopReason: 'cancelled' })
   })
 
+  it('correlates a prompt whose admitted history is replaced', async () => {
+    harness = await makeBridgeHarness({ script: [textResponse('rewritten answer')] })
+    harness.ctx.on('agent/prompt-submit', async () => ({
+      kind: 'allow',
+      messages: [createUserMessage({
+        content: [{ type: 'text', text: 'rewritten prompt' }],
+        source: { kind: 'plugin', plugin: 'test' },
+      })],
+    }))
+    const sessionId = await newSession(harness)
+
+    await expect(harness.client.prompt({ sessionId, prompt: [{ type: 'text', text: 'original' }] }))
+      .resolves.toEqual({ stopReason: 'end_turn' })
+  })
+
   it('frees the prompt slot when the agent rejects the send synchronously', async () => {
     harness = await makeBridgeHarness({ script: [] })
     const sessionId = await newSession(harness)
@@ -143,7 +160,8 @@ describe('ACP prompt lifecycle', () => {
     await harness.client.cancel({ sessionId })
     await expect(prompt).resolves.toEqual({ stopReason: 'cancelled' })
     await agent.whenIdle()
-    expect(agent.session.events.findLast(event => event.type === 'turn/end')?.data.reason).toEqual({ kind: 'aborted' })
+    expect(agent.session.events.findLast(event => event.type === 'turn/end')?.data.reason)
+      .toEqual({ kind: 'aborted', reason: { kind: 'user' } })
   })
 
   it('an idle cancel does not affect the following prompt', async () => {
@@ -203,4 +221,29 @@ describe('ACP prompt lifecycle', () => {
     // The blocked prompt opened no turn and streamed nothing.
     expect(messageText(harness)).toBe('')
   })
+
+  it('discards and settles a turnless prompt retained by its admission policy', async () => {
+    harness = await makeBridgeHarness({ script: [] })
+    harness.ctx.on('agent/prompt-submit', async () => ({
+      kind: 'block' as const,
+      reason: 'defer forever',
+      keepInbox: true,
+    }))
+    const sessionId = await newSession(harness)
+    const agent = harness.ctx.agents.get(SessionId(sessionId))!
+
+    await expect(harness.client.prompt({ sessionId, prompt: [{ type: 'text', text: 'go' }] }))
+      .resolves.toEqual({ stopReason: 'cancelled' })
+    expect(agent.status).toBe('idle')
+    expect(agent.session.events.some(event => event.type === 'turn/start')).toBe(false)
+  })
+
+  it('settles a prompt when admission fails before opening a turn', async () => {
+    harness = await makeBridgeHarness({ script: [] })
+    harness.ctx.on('agent/prompt-submit', async () => { throw new Error('admission exploded') })
+    const sessionId = await newSession(harness)
+
+    await expect(harness.client.prompt({ sessionId, prompt: [{ type: 'text', text: 'go' }] }))
+      .resolves.toEqual({ stopReason: 'cancelled' })
+  })
 })
diff --git a/packages/client/connection/src/client/api.ts b/packages/client/connection/src/client/api.ts
index b58718134d..23aa0d20c0 100644
--- a/packages/client/connection/src/client/api.ts
+++ b/packages/client/connection/src/client/api.ts
@@ -12,7 +12,7 @@ export type {
   WorkspaceApi, WorkspaceId, WorkspaceView,
   CommandsApi, CommandDescriptor, SkillsApi, SkillEntry,
   ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
-  InboxItemId, ModelReasoningEffort, ModelTarget, QueueAction, QueuedInboxItem, SessionModels,
+  ModelReasoningEffort, ModelTarget, QueueAction, SessionModels,
   GoalsApi, GoalRef,
 } from '@deepseek-ai/dsh-host-apiproxy/api'
 export type { ToolCallView, ToolResultView } from '@deepseek-ai/dsh-tools/presentation'
@@ -27,6 +27,7 @@ export { RpcId, transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
 export { AbstractApiClient } from '@deepseek-ai/dsh-host-apiproxy/client'
 export type { IApiClient } from '@deepseek-ai/dsh-host-apiproxy/client'
 export type { SessionId, SessionEvent } from '@deepseek-ai/dsh-session/types'
+export type { MessageId } from '@deepseek-ai/dsh-llm/brand'
 export type { ContentBlock, StreamChunk } from '@deepseek-ai/dsh-llm/types'
 
 import type { RpcResponse, RpcResult } from '@deepseek-ai/dsh-host-apiproxy/api'
diff --git a/packages/client/connection/src/client/index.ts b/packages/client/connection/src/client/index.ts
index 7d26b1c526..1599084c1c 100644
--- a/packages/client/connection/src/client/index.ts
+++ b/packages/client/connection/src/client/index.ts
@@ -17,7 +17,7 @@ export type {
   ToolCallView, ToolResultView, WorkspaceApi, WorkspaceId, WorkspaceView,
   CommandsApi, CommandDescriptor, SkillsApi, SkillEntry,
   ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
-  InboxItemId, ModelReasoningEffort, ModelTarget, QueueAction, QueuedInboxItem, SessionModels,
+  MessageId, ModelReasoningEffort, ModelTarget, QueueAction, SessionModels,
   RpcRequest, RpcResponse, RpcResult, RpcError, RpcErrorCode,
   ClientRequest, ServerResponse, ServerRequest, ClientResponse, RpcMessage, RpcReceipt,
   IApiClient, SessionId, SessionEvent, ContentBlock, StreamChunk,
diff --git a/packages/client/runtime/src/client/contract/session.ts b/packages/client/runtime/src/client/contract/session.ts
index 82bde108b4..0e75648ea1 100644
--- a/packages/client/runtime/src/client/contract/session.ts
+++ b/packages/client/runtime/src/client/contract/session.ts
@@ -9,7 +9,7 @@
  */
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
 import type {
-  InboxItemId, QueueAction, RpcResult, SessionId,
+  MessageId, QueueAction, RpcResult, SessionId,
 } from '@deepseek-ai/dsh-client-connection/client'
 import type { ConversationSnapshot } from '../sessions/conversation.ts'
 import type { ObservableSnapshot } from './store.ts'
@@ -44,7 +44,7 @@ export interface ISession {
    * @param action - edit or remove operation.
    * @returns acceptance, or a business/transport error.
    */
-  updateQueue(itemId: InboxItemId, action: QueueAction): Promise<RpcResult<{ accepted: true }>>
+  updateQueue(itemId: MessageId, action: QueueAction): Promise<RpcResult<{ accepted: true }>>
   /**
    * Cancel the running turn.
    * @returns acceptance, or the business error.
diff --git a/packages/client/runtime/src/client/sessions/conversation.ts b/packages/client/runtime/src/client/sessions/conversation.ts
index f68a271c63..55cc3fc73e 100644
--- a/packages/client/runtime/src/client/sessions/conversation.ts
+++ b/packages/client/runtime/src/client/sessions/conversation.ts
@@ -7,7 +7,7 @@ import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
 import type { TodoItem } from '@deepseek-ai/dsh-session/types'
 import type {
-  InboxItemId, RpcError, SessionId, ToolCallView, ToolResultView,
+  MessageId, RpcError, SessionId, ToolCallView, ToolResultView,
 } from '@deepseek-ai/dsh-client-connection/client'
 import type { PendingInteraction } from './pending.ts'
 export type { TodoItem }
@@ -218,7 +218,7 @@ export interface RunningToolCall {
 
 /** One independently addressable row from the transient queue snapshot. */
 export interface QueuedMessage {
-  readonly id: InboxItemId
+  readonly id: MessageId
   readonly preview: string
   /** Complete editable text; null when the message contains non-text blocks. */
   readonly text: string | null
diff --git a/packages/client/runtime/tests/queue-store.spec.ts b/packages/client/runtime/tests/queue-store.spec.ts
index 192885b66b..ce684694f5 100644
--- a/packages/client/runtime/tests/queue-store.spec.ts
+++ b/packages/client/runtime/tests/queue-store.spec.ts
@@ -4,10 +4,10 @@
  * projection, and snapshot reference stability.
  */
 import { describe, expect, it } from 'vitest'
-import { createUserMessage } from '@deepseek-ai/dsh-llm'
+import { createUserMessage, freezeMessage } from '@deepseek-ai/dsh-llm'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
 import type {
-  InboxItemId, MuxFrame, RpcId, SessionId,
+  MessageId, MuxFrame, RpcId, SessionId,
 } from '@deepseek-ai/dsh-client-connection/client'
 import { Session } from '../src/client/sessions/session.ts'
 import { SessionManager } from '../src/client/sessions/manager.ts'
@@ -16,7 +16,7 @@ import { FakeApiClient } from './fake-api.ts'
 const SID = 'fk-q1' as SessionId
 const text = (value: string): ContentBlock[] => [{ type: 'text', text: value }]
 const rid = (id: string): RpcId => id as RpcId
-const iid = (id: string): InboxItemId => id as InboxItemId
+const mid = (id: string): MessageId => id as MessageId
 
 interface QueueFixture {
   id: string
@@ -29,12 +29,12 @@ function queueFrame(items: QueueFixture[]): MuxFrame {
   return {
     type: 'session/queue',
     sessionId: SID,
-    items: items.map(item => ({
-      id: iid(item.id),
-      message: createUserMessage({
+    items: items.map(item => freezeMessage({
+      ...createUserMessage({
         content: item.content ?? text(item.body),
         source: { kind: 'user', rpcId: rid(`rpc-${item.id}`) } as never,
       }),
+      id: mid(item.id),
     })),
   }
 }
diff --git a/packages/client/ui-conversation/src/client/input/contract.ts b/packages/client/ui-conversation/src/client/input/contract.ts
index 317adc0ec5..0c1d72dbc2 100644
--- a/packages/client/ui-conversation/src/client/input/contract.ts
+++ b/packages/client/ui-conversation/src/client/input/contract.ts
@@ -191,7 +191,7 @@ export interface InputState {
   readonly occurrences: readonly Occurrence[]
   /** Live paste-match attempt (absent when no paste is matchable). */
   readonly paste?: PasteAttemptState
-  /** Read-only queue projection (session/queued frames + connect snapshot). */
+  /** Read-only queue projection from the reconnect baseline and durable inbox events. */
   readonly queue: readonly QueuedMessage[]
 }
 
diff --git a/packages/context/time-context/tests/time-context.spec.ts b/packages/context/time-context/tests/time-context.spec.ts
index ea13a36728..377e11abd7 100644
--- a/packages/context/time-context/tests/time-context.spec.ts
+++ b/packages/context/time-context/tests/time-context.spec.ts
@@ -41,10 +41,7 @@ function sessionAgent(session: Session, id = 'agent'): Agent {
     options: {},
     session,
     status: 'running',
-    acceptsNextStep: true,
     ctx: new Context(),
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject(input) {
diff --git a/packages/context/tmux-context/tests/tmux-context.spec.ts b/packages/context/tmux-context/tests/tmux-context.spec.ts
index 4c96fe0a78..a3a78c0153 100644
--- a/packages/context/tmux-context/tests/tmux-context.spec.ts
+++ b/packages/context/tmux-context/tests/tmux-context.spec.ts
@@ -97,15 +97,12 @@ function sessionAgent(session: Session, id = 'agent'): Agent {
     options: {},
     session,
     status: 'running',
-    acceptsNextStep: true,
     ctx: new Context(),
     followup: () => {},
     steer: () => {},
-    updateInbox: () => 'not-found',
     inject(input) {
       session.append('user/message', input, { surfaceOp: 'append' })
     },
-    send: () => {},
     cancel() {},
     whenIdle: () => Promise.resolve(),
   }
diff --git a/packages/context/workspace-context/tests/workspace-context.spec.ts b/packages/context/workspace-context/tests/workspace-context.spec.ts
index ad6eb500a7..cb4ca3533f 100644
--- a/packages/context/workspace-context/tests/workspace-context.spec.ts
+++ b/packages/context/workspace-context/tests/workspace-context.spec.ts
@@ -177,9 +177,6 @@ function stubAgent(cwd?: string, seed: SessionEvent[] = []): Agent {
     options: {},
     session,
     status: 'idle',
-    acceptsNextStep: false,
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject(input) {
diff --git a/packages/core/agent-loop/src/agent.ts b/packages/core/agent-loop/src/agent.ts
index d42c2790d3..f33e36a3e3 100644
--- a/packages/core/agent-loop/src/agent.ts
+++ b/packages/core/agent-loop/src/agent.ts
@@ -1,9 +1,6 @@
 /**
- * Concrete Agent loop over two pending-input lists: queued prompts each open a
- * turn that logs its admitted input after `turn/start` commits, while steering
- * and injected context enter through the outbox at step boundaries. Every
- * request is derived from the session log.
- *
+ * Default Agent driver over queued turns and step-boundary input. Every request
+ * is derived from the session log.
  * @module dsh-agent-loop/agent
  */
 
@@ -13,9 +10,10 @@ import type {
   AgentOptions,
   AgentStatus,
   CancelOptions,
+  InboxTarget,
   RequestErrorAction,
 } from '@deepseek-ai/dsh-agent'
-import { agentCarrier, agentEvents, assembleContextFor, emitAgentEvent } from '@deepseek-ai/dsh-agent'
+import { Inbox, agentCarrier, agentEvents, assembleContextFor, emitAgentEvent } from '@deepseek-ai/dsh-agent'
 import type { GenerateOptions, LlmCallConfig, Message, PreparedLlmCall } from '@deepseek-ai/dsh-llm'
 import {
   BlockAssembler,
@@ -27,7 +25,7 @@ import {
 } from '@deepseek-ai/dsh-llm'
 import type { Scope } from '@deepseek-ai/dsh-scope'
 import { createScope } from '@deepseek-ai/dsh-scope'
-import type { AssistantMessage, Session, SessionId, TurnEndReason, UserMessage } from '@deepseek-ai/dsh-session'
+import type { Session, SessionId, TurnEndReason, UserMessage } from '@deepseek-ai/dsh-session'
 import { canonicalHeader, headerEquals } from '@deepseek-ai/dsh-session'
 import { renderPrompt } from '@deepseek-ai/dsh-system-prompt'
 import type { Context } from 'cordis'
@@ -40,25 +38,17 @@ type Phase =
 
 type Admission =
   | { kind: 'empty' }
-  | { kind: 'admitted'; claimed: UserMessage[]; messages: UserMessage[] }
+  | { kind: 'admitted'; messages: UserMessage[] }
   | { kind: 'blocked' }
 
-/**
- * The concrete {@link Agent}: each `run()` owns one turn and repeats model
- * steps while tools or steering require another request.
- */
+/** Drives one session through turn and step boundaries. */
 export class ReactLoopAgent implements Agent {
-  /** Prompts awaiting individual turns. */
-  private queued: UserMessage[] = []
-  /** Input taken into the session log at step boundaries. */
-  private outbox: UserMessage[] = []
-
+  readonly inbox: Inbox
   private phase: Phase
   private driverDone: Promise<void> = Promise.resolve()
 
   /** The agent-scoped registration boundary; the lifecycle owner unwinds it after the driver exits. */
   readonly scope: Scope
-  /** The agent's scoped composition context ({@link Agent.ctx}). */
   readonly ctx: Context
 
   /** Whether this loop instance has appended its initial/resume request anchor. */
@@ -70,13 +60,13 @@ export class ReactLoopAgent implements Agent {
     public readonly options: AgentOptions,
     public readonly session: Session,
   ) {
+    this.inbox = new Inbox(session)
     const lastTurn = session.events.findLast(event => event.type === 'turn/start')?.data.turn ?? 0
     this.phase = { kind: 'idle', lastTurn }
     this.scope = createScope(loopCtx, this)
     this.ctx = this.scope.ctx.extend({ agent: this })
   }
 
-  /** Last activity state published to observers. */
   get status(): AgentStatus {
     return this.phase.kind === 'idle' ? 'idle' : 'running'
   }
@@ -91,49 +81,32 @@ export class ReactLoopAgent implements Agent {
     }
   }
 
-  /** Accept and route one unified send item. */
-  private send(message: UserMessage, target: 'next-turn' | 'next-step', wakeup: boolean): void {
-    this.session.append('agent/inbox/added', message)
+  private send(message: UserMessage, target: InboxTarget, wakeup: boolean): void {
     // Waking input cannot join an aborted admission or turn, so it starts the next turn.
     const wakingAfterAbort = wakeup && this.phase.kind !== 'idle' && this.phase.abort.signal.aborted
-    const inbox = target === 'next-turn' || wakingAfterAbort ? this.queued : this.outbox
-    inbox.push(message)
-    if (wakeup) {
-      this.scheduleKick()
-    }
+    const resolvedTarget = wakingAfterAbort ? 'next-turn' : target
+    this.inbox.splice(resolvedTarget, Infinity, 0, [message])
+    if (wakeup) this.scheduleKick()
   }
 
-  /** Queue one ordinary prompt turn and wake the driver. */
   followup(input: UserMessage): void {
     this.send(input, 'next-turn', true)
   }
 
-  /** Steer the open turn, falling back to a waking prompt while idle. */
   steer(input: UserMessage): void {
     this.send(input, 'next-step', true)
   }
 
-  /** Append model-facing context without waking the driver. */
   inject(input: UserMessage): void {
     this.send(input, 'next-step', false)
   }
 
-  /**
-   * Clear all pending work and abort the active turn; the first cause wins.
-   * The cause is signal payload for observers and the durable turn/end
-   * classification — it selects no machine behavior. Teardown is just
-   * `cancel({kind:'disposed'})` + driver join + {@link scope} dispose, all
-   * owned by the factory.
-   */
   cancel(cause: AgentCancelCause, options: CancelOptions = {}): void {
     if (!options.keepInbox) {
-      for (const message of [...this.outbox.splice(0), ...this.queued.splice(0)]) {
-        emitAgentEvent(this.loopCtx, this, 'agent/inbox/canceled', message)
-      }
-    }
-    if (this.phase.kind !== 'idle') {
-      this.phase.abort.abort(cause)
+      this.inbox.splice('next-step', 0, this.inbox.nextStep.length, [], 'canceled')
+      this.inbox.splice('next-turn', 0, this.inbox.nextTurn.length, [], 'canceled')
     }
+    if (this.phase.kind !== 'idle') this.phase.abort.abort(cause)
   }
 
   /** Reserve a driver before deferring idle admission. */
@@ -147,7 +120,6 @@ export class ReactLoopAgent implements Agent {
     })
   }
 
-  /** Resolve after the current driver and synchronous replacement chain exits. */
   async whenIdle(): Promise<void> {
     let driver: Promise<void>
     do {
@@ -171,13 +143,12 @@ export class ReactLoopAgent implements Agent {
     }
   }
 
-  /** Claim and admit the next queued prompt, then start its turn. */
   private async admit(onTurnBoundary: boolean): Promise<Admission> {
     if (this.phase.kind !== 'running') throw new Error()
     const signal = this.phase.abort.signal
-    const claimed = this.outbox.slice()
-    const outboxLength = this.outbox.length
-    const queued = onTurnBoundary ? this.queued[0] : undefined
+    const claimed = [...this.inbox.nextStep]
+    const outboxLength = this.inbox.nextStep.length
+    const queued = onTurnBoundary ? this.inbox.nextTurn[0] : undefined
     if (queued !== undefined) claimed.push(queued)
     if (claimed.length === 0) return { kind: 'empty' }
     const decision = await agentEvents(this.loopCtx, this).waterfall(
@@ -186,34 +157,31 @@ export class ReactLoopAgent implements Agent {
     )
     signal.throwIfAborted()
     if (decision.kind === 'allow') {
-      this.outbox.splice(0, outboxLength)
-      if (queued !== undefined) this.queued.shift()
-      return { kind: 'admitted', claimed, messages: decision.messages }
-    } else {
-      this.cancel({ kind: 'hook', reason: decision.reason }, { keepInbox: decision.keepInbox })
-      return { kind: 'blocked' }
+      this.inbox.splice('next-step', 0, outboxLength, [], 'admitted')
+      if (queued !== undefined) this.inbox.splice('next-turn', 0, 1, [], 'admitted')
+      return { kind: 'admitted', messages: decision.messages }
     }
+    this.cancel({ kind: 'hook', reason: decision.reason }, { keepInbox: decision.keepInbox })
+    return { kind: 'blocked' }
   }
 
-  /**
-   * Run one turn and any request-error retry. `admitted` input enters the log
-   * only after `turn/start` commits; until then it has no owner state to unwind.
-   */
+  /** Admitted input stays unowned until `turn/start` commits. */
   private async turn(): Promise<boolean> {
     if (this.phase.kind === 'idle') throw new Error()
     const abort = this.phase.kind === 'collecting' ? this.phase.abort : new AbortController()
+    const { signal } = abort
     const lastTurn = this.phase.kind === 'collecting' ? this.phase.lastTurn : this.phase.turn
     const phase = { kind: 'running' as const, abort, turn: lastTurn, step: 0 }
     this.setPhase(phase)
-    if (abort.signal.aborted) return this.outbox.length > 0 || this.queued.length > 0
+    if (signal.aborted) return this.inbox.hasPending
     let admission: Admission
     try {
       admission = await this.admit(true)
       if (admission.kind !== 'admitted') return false
-      abort.signal.throwIfAborted()
+      signal.throwIfAborted()
     } catch (error: unknown) {
       // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition -- cancel may abort while admission awaits
-      if (abort.signal.aborted) return this.outbox.length > 0 || this.queued.length > 0
+      if (signal.aborted) return this.inbox.hasPending
       throw error
     }
     const turn = ++phase.turn
@@ -222,14 +190,11 @@ export class ReactLoopAgent implements Agent {
     try {
       while (true) {
         if (admission.kind === 'admitted') {
-          for (const message of admission.claimed) {
-            emitAgentEvent(this.loopCtx, this, 'agent/inbox/admitted', message)
-          }
           for (const message of admission.messages) {
             this.session.append('user/message', message, { surfaceOp: 'append' })
           }
         }
-        abort.signal.throwIfAborted()
+        signal.throwIfAborted()
         const step = ++phase.step
         this.session.append('step/start', { turn, step })
         try {
@@ -237,34 +202,30 @@ export class ReactLoopAgent implements Agent {
         } finally {
           this.session.append('step/end', { turn, step })
         }
-        abort.signal.throwIfAborted()
-        if (turnEnds && this.outbox.length === 0) {
-          await this.loopCtx.serial(agentCarrier(this), 'agent/turn-stopping', this, turn, abort.signal)
-          abort.signal.throwIfAborted()
+        signal.throwIfAborted()
+        if (turnEnds && this.inbox.nextStep.length === 0) {
+          await this.loopCtx.serial(agentCarrier(this), 'agent/turn-stopping', this, turn, signal)
+          signal.throwIfAborted()
         }
         admission = await this.admit(false)
         if (admission.kind === 'blocked') {
-          turnEnds = { kind: 'aborted', reason: abort.signal.reason as AgentCancelCause }
+          turnEnds = { kind: 'aborted', reason: signal.reason as AgentCancelCause }
           return false
         }
-        abort.signal.throwIfAborted()
+        signal.throwIfAborted()
         if (admission.kind === 'empty' && turnEnds) break
       }
     } catch (error: unknown) {
       // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition -- cancel may abort during any awaited turn operation
-      if (abort.signal.aborted) turnEnds = { kind: 'aborted', reason: abort.signal.reason as AgentCancelCause }
+      if (signal.aborted) turnEnds = { kind: 'aborted', reason: signal.reason as AgentCancelCause }
       else turnEnds = { kind: 'error', error: errorChain(error) }
     } finally {
       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- the turn is always ended in this block
       this.session.append('turn/end', { turn, reason: turnEnds! })
     }
-    return this.outbox.length > 0 || this.queued.length > 0
+    return this.inbox.hasPending
   }
 
-  /**
-   * Run the `agent/step` extension point, commit pending input, derive one
-   * request, and execute its tool calls inside one durable step boundary.
-   */
   private async step(): Promise<TurnEndReason | null> {
     if (this.phase.kind !== 'running') throw new Error()
     const { turn, step, abort: { signal } } = this.phase
@@ -275,11 +236,9 @@ export class ReactLoopAgent implements Agent {
     signal.throwIfAborted()
     const system = renderPrompt(assembly)
 
-    let message: AssistantMessage
     while (true) {
-      const boundaryMessages = this.session.deriveMessages()
       const { request, preparedCall } = await this.buildRequest(
-        turn, step, assembly.tools, system, boundaryMessages, signal,
+        turn, step, assembly.tools, system, this.session.deriveMessages(), signal,
       )
       const assembler = new BlockAssembler()
       const chunkSeqs: number[] = []
@@ -287,8 +246,7 @@ export class ReactLoopAgent implements Agent {
       signal.throwIfAborted()
       for await (const chunk of stream) {
         signal.throwIfAborted()
-        const chunkEvent = this.session.append('assistant/chunk', { turn, step, chunk })
-        chunkSeqs.push(chunkEvent.seq)
+        chunkSeqs.push(this.session.append('assistant/chunk', { turn, step, chunk }).seq)
         assembler.push(chunk)
       }
       signal.throwIfAborted()
@@ -305,47 +263,38 @@ export class ReactLoopAgent implements Agent {
           () => Promise.resolve<RequestErrorAction>(undefined),
         )
         signal.throwIfAborted()
-        if (action?.kind !== 'retry') {
-          return { kind: 'error', error: finish.failure }
-        }
-      } else {
-        message = createAssistantMessage({
-          content: assembler.blocks(),
-          source: {
-            provider: request.provider,
-            model: request.model,
-            ...assembler.replayState !== undefined ? { replayState: assembler.replayState } : {},
-          },
-        })
-        this.session.append(
-          'assistant/message',
-          {
-            turn,
-            step,
-            message,
-            ...assembler.usage === undefined ? {} : { usage: assembler.usage },
-          },
-          { surfaceOp: 'append', sourceEventSeqs: chunkSeqs },
-        )
-        if (finish.kind === 'max-tokens') {
-          return { kind: 'max-tokens' }
-        }
-        break
+        if (action?.kind !== 'retry') return { kind: 'error', error: finish.failure }
+        continue
       }
-    }
 
-    const toolCalls = message.content.filter(block => block.type === 'tool-call')
-    let result: TurnEndReason | null
-    if (toolCalls.length > 0) {
+      const message = createAssistantMessage({
+        content: assembler.blocks(),
+        source: {
+          provider: request.provider,
+          model: request.model,
+          ...assembler.replayState !== undefined ? { replayState: assembler.replayState } : {},
+        },
+      })
+      this.session.append(
+        'assistant/message',
+        {
+          turn,
+          step,
+          message,
+          ...assembler.usage === undefined ? {} : { usage: assembler.usage },
+        },
+        { surfaceOp: 'append', sourceEventSeqs: chunkSeqs },
+      )
+      if (finish.kind === 'max-tokens') return { kind: 'max-tokens' }
+
+      const toolCalls = message.content.filter(block => block.type === 'tool-call')
+      if (toolCalls.length === 0) return { kind: 'completed' }
       const { concluded } = await executeToolCalls(
         this.loopCtx, turn, step, toolCalls, signal,
-        context => this.outbox.push(context),
+        context => this.inbox.splice('next-step', this.inbox.nextStep.length, 0, [context]),
       )
-      result = concluded ? { kind: 'completed' } : null
-    } else {
-      result = { kind: 'completed' }
+      return concluded ? { kind: 'completed' } : null
     }
-    return result
   }
 
   /**
@@ -360,8 +309,6 @@ export class ReactLoopAgent implements Agent {
     boundaryMessages: Message[],
     signal: AbortSignal,
   ): Promise<{ request: GenerateOptions; preparedCall?: PreparedLlmCall }> {
-    // A loop instance starts from its declared route, restoring only an opaque
-    // effort owned by that exact model. Later steps fold the config it logged.
     const persistedConfig = this.session.requestHeader()?.config
     const route = { provider: this.options.provider ?? '', model: this.options.model ?? '' }
     const reasoningEffort = persistedConfig?.provider === route.provider
@@ -369,16 +316,14 @@ export class ReactLoopAgent implements Agent {
       ? persistedConfig.reasoningEffort
       : undefined
     const maxTokens = this.options.maxTokens
-    const seedConfig = deepFreeze(structuredClone(
-      this.requestHeaderLogged
-        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- the instance logged the header it now folds
-        ? persistedConfig!
-        : {
-          ...route,
-          ...reasoningEffort === undefined ? {} : { reasoningEffort },
-          ...maxTokens === undefined ? {} : { maxTokens },
-        },
-    ))
+    const seedConfig = this.requestHeaderLogged
+      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- the instance logged the frozen header it now folds
+      ? persistedConfig!
+      : deepFreeze({
+        ...route,
+        ...reasoningEffort === undefined ? {} : { reasoningEffort },
+        ...maxTokens === undefined ? {} : { maxTokens },
+      })
     const proposedConfig = await this.loopCtx.waterfall(
       agentCarrier(this), 'agent/request', this, turn, step, signal,
       () => Promise.resolve(seedConfig),
@@ -393,8 +338,7 @@ export class ReactLoopAgent implements Agent {
       preparedCall = await this.loopCtx.llm.prepareCall(proposedConfig, signal)
       config = preparedCall.config
     } catch (error: unknown) {
-      // A llm/stream listener may own and short-circuit a route with no
-      // adapter. Terminal dispatch still raises NO_ADAPTER when none does.
+      // Middleware may serve an unregistered route; terminal dispatch still requires an adapter.
       if (!(error instanceof LlmError) || error.code !== 'NO_ADAPTER') throw error
       config = proposedConfig
     }
diff --git a/packages/core/agent-loop/tests/cancel.spec.ts b/packages/core/agent-loop/tests/cancel.spec.ts
index 1bc9d58406..87796c97b6 100644
--- a/packages/core/agent-loop/tests/cancel.spec.ts
+++ b/packages/core/agent-loop/tests/cancel.spec.ts
@@ -76,8 +76,6 @@ describe('Agent.cancel()', () => {
     const adapter = new MockAdapter([textResponse('reply')])
     const ctx = await harness(adapter)
     const agent = ctx.agentLoop.create(SessionId('a1'), { provider: 'mock', model: 'mock' })
-    const canceled: unknown[] = []
-    ctx.on('agent/inbox/canceled', (subject, message) => { if (subject === agent) canceled.push(message) })
 
     agent.followup(createUserMessage({
       content: [{ type: 'text', text: 'preserved' }],
@@ -85,7 +83,8 @@ describe('Agent.cancel()', () => {
     }))
     // Abort the collecting activity while preserving its queued item.
     agent.cancel({ kind: 'user' }, { keepInbox: true })
-    expect(canceled).toEqual([])
+    expect(agent.session.events.some(event =>
+      event.type === 'agent/inbox/spliced' && event.data.outcome === 'canceled')).toBe(false)
 
     // The preserved item still runs once a later follow-up wakes the driver.
     send(agent, 'wake it')
diff --git a/packages/core/agent-loop/tests/contract-regressions.spec.ts b/packages/core/agent-loop/tests/contract-regressions.spec.ts
index 31e6d7c2b1..a87afb578b 100644
--- a/packages/core/agent-loop/tests/contract-regressions.spec.ts
+++ b/packages/core/agent-loop/tests/contract-regressions.spec.ts
@@ -1,10 +1,10 @@
 import { describe, expect, it } from 'vitest'
 import { Context } from 'cordis'
-import LlmService, { createUserMessage, CallId, MessageSource, ProviderRequestId, StreamChunk  } from '@deepseek-ai/dsh-llm'
+import LlmService, { createUserMessage, freezeMessage, CallId, MessageSource, ProviderRequestId, StreamChunk  } from '@deepseek-ai/dsh-llm'
 import SessionStore, { Session, SessionEvent, SessionId, TurnEndReason } from '@deepseek-ai/dsh-session'
 import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
 import ToolRegistry, { defineContentToolFixture, type PostToolDecision } from '@deepseek-ai/dsh-tools'
-import AgentRegistry, { type Agent, type InboxItem, type InboxPlacement } from '@deepseek-ai/dsh-agent'
+import AgentRegistry, { type Agent } from '@deepseek-ai/dsh-agent'
 import AgentLoop from '@deepseek-ai/dsh-agent-loop'
 import { ReactLoopAgent } from '../src/agent.ts'
 import InvariantService from '@deepseek-ai/dsh-invariants'
@@ -53,8 +53,8 @@ function send(agent: Agent, text: string) {
   agent.followup(createUserMessage({ content: [{ type: 'text', text }], source: { kind: 'user' } }))
 }
 
-function inboxText(item: InboxItem): string {
-  return item.message.content
+function inboxText(message: UserMessage): string {
+  return message.content
     .flatMap(block => block.type === 'text' ? [block.text] : [])
     .join('')
 }
@@ -69,42 +69,28 @@ describe('addressable inbox operations', () => {
     const agent = ctx.agentLoop.create(SessionId('inbox-actions'), { provider: 'mock', model: 'mock' })
     const admission = Promise.withResolvers<undefined>()
     const release = Promise.withResolvers<undefined>()
-    ctx.on('agent/prompt-submit', async (_subject, message, _signal, next) => {
-      if (message.content[0]?.type === 'text' && message.content[0].text === 'first') {
+    ctx.on('agent/prompt-submit', async (_subject, messages, _signal, next) => {
+      if (messages[0]?.content[0]?.type === 'text' && messages[0].content[0].text === 'first') {
         admission.resolve(undefined)
         await release.promise
       }
       return next()
     })
 
-    const pending: InboxItem[] = []
-    const updates: { id: string; text: string }[] = []
-    const discards: string[][] = []
-    ctx.on('agent/inbox/enqueue', (subject, item) => {
-      if (subject === agent && inboxText(item) !== 'first') pending.push(item)
-    })
-    ctx.on('agent/inbox/update', (subject, item) => {
-      if (subject === agent) updates.push({ id: item.id, text: inboxText(item) })
-    })
-    ctx.on('agent/inbox/discard', (subject, items) => {
-      if (subject === agent) discards.push(items.map(item => item.id))
-    })
-
     send(agent, 'first')
     await admission.promise
     send(agent, 'remove me')
     send(agent, 'edit me')
+    const pending = agent.inbox.nextTurn
     expect(pending.map(inboxText)).toEqual(['remove me', 'edit me'])
 
     const remove = pending[0]!
     const edit = pending[1]!
-    expect(agent.updateInbox(edit.id, {
-      kind: 'edit',
+    expect(agent.inbox.splice('next-turn', 1, 1, [freezeMessage({
+      ...edit,
       content: [{ type: 'text', text: 'edited' }],
-    })).toBe('applied')
-    expect(agent.updateInbox(remove.id, { kind: 'remove' })).toBe('applied')
-    expect(updates).toEqual([{ id: edit.id, text: 'edited' }])
-    expect(discards).toEqual([[remove.id]])
+    })])).toEqual([edit])
+    expect(agent.inbox.splice('next-turn', 0, 1, [])).toEqual([remove])
 
     const idle = waitForIdle(ctx, agent)
     release.resolve(undefined)
@@ -115,46 +101,7 @@ describe('addressable inbox operations', () => {
         ? event.data.content.flatMap(block => block.type === 'text' ? [block.text] : []).join('')
         : ''))
       .toEqual(['first', 'edited'])
-    expect(agent.updateInbox(edit.id, { kind: 'remove' })).toBe('not-found')
-  })
-
-  it('does not mutate steering occurrences', async () => {
-    const adapter = new MockAdapter([textResponse('done')])
-    const ctx = await harness(adapter)
-    const agent = ctx.agentLoop.create(SessionId('steering-inbox-actions'), { provider: 'mock', model: 'mock' })
-    const entered = Promise.withResolvers<undefined>()
-    const decision = Promise.withResolvers<{ kind: 'allow' }>()
-    ctx.on('agent/prompt-submit', async () => {
-      entered.resolve(undefined)
-      return decision.promise
-    })
-
-    const pending: InboxItem[] = []
-    ctx.on('agent/inbox/enqueue', (subject, item) => {
-      if (subject === agent && item.placement === 'steering') pending.push(item)
-    })
-
-    const idle = waitForIdle(ctx, agent)
-    send(agent, 'admitted prompt')
-    await entered.promise
-    agent.steer(createUserMessage({ content: [{ type: 'text', text: 'keep me' }], source: { kind: 'user' } }))
-    expect(pending.map(inboxText)).toEqual(['keep me'])
-
-    const steering = pending[0]!
-    expect(agent.updateInbox(steering.id, {
-      kind: 'edit',
-      content: [{ type: 'text', text: 'edited' }],
-    })).toBe('not-found')
-    expect(agent.updateInbox(steering.id, { kind: 'remove' })).toBe('not-found')
-
-    decision.resolve({ kind: 'allow' })
-    await idle
-    expect(agent.session.events
-      .filter(event => event.type === 'steering/message')
-      .map(event => event.type === 'steering/message'
-        ? event.data.message.content.flatMap(block => block.type === 'text' ? [block.text] : []).join('')
-        : ''))
-      .toEqual(['keep me'])
+    expect(agent.inbox.splice('next-turn', 0, 1, [])).toEqual([])
   })
 })
 
@@ -590,7 +537,7 @@ describe('adapter registration, routing, and accepted-input ownership', () => {
     expect(agent.session.deriveMessages().at(-1)?.content).toEqual([{ type: 'text', text: 'routed' }])
   })
 
-  it('agent/inbox/enqueue carries the exact message; steering/message records its source', async () => {
+  it('durable inbox splices carry exact messages and steering/message preserves its source', async () => {
     const adapter = new MockAdapter([toolCallResponse('c1', 'noop', {}), textResponse('done')])
     const ctx = await harness(adapter)
     const agent = ctx.agentLoop.create(SessionId('a1'), { provider: 'mock', model: 'mock' })
@@ -604,27 +551,30 @@ describe('adapter registration, routing, and accepted-input ownership', () => {
       },
     }))
 
-    const queuedSources: MessageSource[] = []
-    const queuedShapes: string[][] = []
-    const placements: InboxPlacement[] = []
-    ctx.on('agent/inbox/enqueue', (_agent, item) => {
-      queuedSources.push(item.message.source)
-      queuedShapes.push(Object.keys(item.message).sort())
-      placements.push(item.placement)
+    const insertedSources: MessageSource[] = []
+    const insertedShapes: string[][] = []
+    const targets: string[] = []
+    ctx.on('session/event', (session, event) => {
+      if (session !== agent.session || event.type !== 'agent/inbox/spliced') return
+      for (const message of event.data.inserted) {
+        insertedSources.push(message.source)
+        insertedShapes.push(Object.keys(message).sort())
+        targets.push(event.data.target)
+      }
     })
 
     send(agent, 'go') // no explicit source → default {kind:'user'} must be visible
     await waitForIdle(ctx, agent)
 
-    expect(queuedSources).toEqual([
+    expect(insertedSources).toEqual([
       { kind: 'user' },
       { kind: 'plugin', plugin: 'goal' },
     ])
-    expect(queuedShapes).toEqual([
+    expect(insertedShapes).toEqual([
       ['content', 'id', 'role', 'source'],
       ['content', 'id', 'role', 'source'],
     ])
-    expect(placements).toEqual(['queued', 'steering'])
+    expect(targets).toEqual(['next-turn', 'next-step'])
     // The drain appends the durable steering/message with the caller's source
     // intact — the log, not a transient emit, is where consumers read it.
     const steeringSources = agent.session.events.flatMap(e => e.type === 'steering/message' ? [e.data.message.source] : [])
diff --git a/packages/core/agent/package.json b/packages/core/agent/package.json
index 9113030eef..db0637ecc2 100644
--- a/packages/core/agent/package.json
+++ b/packages/core/agent/package.json
@@ -15,10 +15,6 @@
       "types": "./lib/types/invariant.d.ts",
       "default": "./lib/invariant.js"
     },
-    "./brand": {
-      "types": "./lib/types/brand.d.ts",
-      "default": "./lib/types/brand.js"
-    },
     "./src/*": "./src/*",
     "./package.json": "./package.json"
   },
@@ -32,7 +28,6 @@
   ],
   "license": "BSD-3-Clause",
   "peerDependencies": {
-    "@deepseek-ai/dsh-brand": "^0.0.1",
     "@deepseek-ai/dsh-invariants": "^0.0.1",
     "@deepseek-ai/dsh-llm": "^0.0.1",
     "@deepseek-ai/dsh-scope": "^0.0.1",
@@ -41,7 +36,6 @@
     "cordis": "^4.0.0-rc.7"
   },
   "devDependencies": {
-    "@deepseek-ai/dsh-brand": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
     "@deepseek-ai/dsh-scope": "workspace:^",
diff --git a/packages/core/agent/src/brand.ts b/packages/core/agent/src/brand.ts
deleted file mode 100644
index 58d50259c1..0000000000
--- a/packages/core/agent/src/brand.ts
+++ /dev/null
@@ -1,23 +0,0 @@
-/**
- * dsh-agent's owned branded ids for live inbox occurrences.
- *
- * @module @deepseek-ai/dsh-agent/brand
- */
-
-import type { Branded } from '@deepseek-ai/dsh-brand'
-
-/**
- * Identifies one accepted occurrence in an agent inbox. Re-sending the same
- * message creates a distinct item id, so pending work remains independently
- * addressable.
- */
-export type InboxItemId = Branded<'InboxItemId'>
-
-/**
- * Brand a string as an {@link InboxItemId}.
- * @param id - the agent-loop-minted occurrence identifier.
- * @returns the same string, branded; no validation is performed.
- */
-export function InboxItemId(id: string): InboxItemId {
-  return id as InboxItemId
-}
diff --git a/packages/core/agent/src/inbox.ts b/packages/core/agent/src/inbox.ts
new file mode 100644
index 0000000000..d6dafa7e4e
--- /dev/null
+++ b/packages/core/agent/src/inbox.ts
@@ -0,0 +1,109 @@
+/**
+ * Incremental projection of durable agent inbox events.
+ *
+ * @module @deepseek-ai/dsh-agent/inbox
+ */
+
+import type { Session, SessionEventMap, UserMessage } from '@deepseek-ai/dsh-session'
+
+/** One of the two ordered pending-message lists owned by an agent. */
+export type InboxTarget = 'next-turn' | 'next-step'
+
+/** Mutable state privately owned by an {@link Inbox}. */
+type InboxState = Record<InboxTarget, UserMessage[]>
+
+/** A replay-once projection that incrementally consumes later inbox splices. */
+export class Inbox {
+  private readonly state: InboxState = { 'next-turn': [], 'next-step': [] }
+
+  constructor(private readonly session: Session) {
+    for (const event of session.events.slice(session.header.seedLength ?? 0)) {
+      if (event.type !== 'agent/inbox/spliced') continue
+      try {
+        this.apply(event.data)
+      } catch (error: unknown) {
+        throw new Error(`invalid persisted inbox splice at session seq ${event.seq}`, { cause: error })
+      }
+    }
+  }
+
+  /** Prompts awaiting individual turns. */
+  get nextTurn(): readonly UserMessage[] {
+    return this.state['next-turn']
+  }
+
+  /** Input awaiting admission at a step boundary. */
+  get nextStep(): readonly UserMessage[] {
+    return this.state['next-step']
+  }
+
+  /** Whether either pending-message list contains work. */
+  get hasPending(): boolean {
+    return this.nextTurn.length > 0 || this.nextStep.length > 0
+  }
+
+  /**
+   * Apply standard splice semantics and durably record the normalized result.
+   * @param target - pending list to mutate.
+   * @param start - splice position.
+   * @param deleteCount - maximum number of messages to remove.
+   * @param inserted - messages to insert at the resolved position.
+   * @param outcome - terminal disposition of removed messages.
+   * @returns messages removed by the splice.
+   */
+  splice(
+    target: InboxTarget,
+    start: number,
+    deleteCount: number,
+    inserted: UserMessage[],
+    outcome?: 'admitted' | 'canceled',
+  ): UserMessage[] {
+    const inbox = this.state[target]
+    const offset = Math.trunc(start) || 0
+    const actualStart = offset < 0
+      ? Math.max(inbox.length + offset, 0)
+      : Math.min(offset, inbox.length)
+    const actualDeleteCount = Math.min(
+      Math.max(Math.trunc(deleteCount) || 0, 0),
+      inbox.length - actualStart,
+    )
+    if (actualDeleteCount === 0 && inserted.length === 0) return []
+    const resolvedOutcome = outcome ?? (actualDeleteCount > 0 ? 'canceled' : undefined)
+    const splice = {
+      target,
+      start: actualStart,
+      ...(actualDeleteCount === 0 ? {} : { removedCount: actualDeleteCount }),
+      inserted,
+      ...(resolvedOutcome === undefined ? {} : { outcome: resolvedOutcome }),
+    }
+    this.validate(splice)
+    const event = this.session.append('agent/inbox/spliced', splice)
+    return inbox.splice(actualStart, actualDeleteCount, ...event.data.inserted)
+  }
+
+  /** Apply one normalized durable splice to the projection. */
+  private apply(splice: SessionEventMap['agent/inbox/spliced']): UserMessage[] {
+    this.validate(splice)
+    const inbox = this.state[splice.target]
+    return inbox.splice(splice.start, splice.removedCount ?? 0, ...splice.inserted)
+  }
+
+  /** Validate one normalized splice against the current projection. */
+  private validate(splice: SessionEventMap['agent/inbox/spliced']): void {
+    const inbox = this.state[splice.target]
+    const removedCount = splice.removedCount ?? 0
+    if (!Number.isSafeInteger(splice.start) || splice.start < 0 || splice.start > inbox.length
+      || !Number.isSafeInteger(removedCount) || removedCount < 0
+      || splice.start + removedCount > inbox.length) {
+      throw new Error('invalid inbox splice')
+    }
+    const candidate = inbox.toSpliced(splice.start, removedCount, ...splice.inserted)
+    const ids = new Set<string>()
+    for (const message of splice.target === 'next-turn'
+      ? [...candidate, ...this.nextStep]
+      : [...this.nextTurn, ...candidate]) {
+      if (ids.has(message.id)) throw new Error(`message "${message.id}" is already pending`)
+      ids.add(message.id)
+    }
+  }
+}
diff --git a/packages/core/agent/src/index.ts b/packages/core/agent/src/index.ts
index 0d87778135..d46d8833c5 100644
--- a/packages/core/agent/src/index.ts
+++ b/packages/core/agent/src/index.ts
@@ -15,7 +15,7 @@ import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session'
 import type { Agent, AgentOptions } from './types.ts'
 
 export * from './types.ts'
-export * from './brand.ts'
+export * from './inbox.ts'
 export * from './llm-target.ts'
 export { agentCarrier, agentEvents, assembleContextFor, emitAgentEvent } from './dispatch.ts'
 export type { AgentEventDispatch, AgentSubjectEvent } from './dispatch.ts'
diff --git a/packages/core/agent/src/types.ts b/packages/core/agent/src/types.ts
index 804ad4a963..b1451768ca 100644
--- a/packages/core/agent/src/types.ts
+++ b/packages/core/agent/src/types.ts
@@ -7,10 +7,10 @@
 
 import type { Context } from 'cordis'
 import type { Scoped } from '@deepseek-ai/dsh-scope'
-import type { ContentBlock, LlmCallConfig, LlmFailure, ResolvedRetryPolicy } from '@deepseek-ai/dsh-llm'
+import type { LlmCallConfig, LlmFailure, ResolvedRetryPolicy } from '@deepseek-ai/dsh-llm'
 import type { AgentCancelCause, Session, SessionId, UserMessage } from '@deepseek-ai/dsh-session'
 export type { AgentCancelCause } from '@deepseek-ai/dsh-session'
-import type { InboxItemId } from './brand.ts'
+import type { Inbox, InboxTarget } from './inbox.ts'
 import type {} from '@deepseek-ai/dsh-system-prompt'
 declare module '@deepseek-ai/dsh-system-prompt' {
   interface AssembleContext {
@@ -29,63 +29,12 @@ export interface AgentOptions {
   maxTokens?: number
 }
 
-/**
- * Which inbox queue a {@link Agent.send} item joins:
- * - `next-turn` — the item becomes its own turn, claimed at a turn boundary.
- * - `next-step` — during prompt admission or an open turn, the item stages for
- *   the next safe step boundary; otherwise it is promoted per its `wakeup`
- *   flag.
- */
-export type SendTarget = 'next-turn' | 'next-step'
-
-/** Resolved inbox placement reported when an accepted message is enqueued. */
-export type InboxPlacement = 'queued' | 'steering'
-
-/** One independently addressable accepted occurrence in an agent inbox. */
-export interface InboxItem {
-  /** Agent-loop-minted occurrence identity. */
-  readonly id: InboxItemId
-  /** Identified message delivered by the caller. */
-  readonly message: UserMessage
-  /** Acceptance-time FIFO classification. */
-  readonly placement: InboxPlacement
-}
-
-/** A user-requested mutation of one still-pending queued occurrence. */
-export type InboxAction =
-  | { readonly kind: 'edit'; readonly content: ContentBlock[] }
-  | { readonly kind: 'remove' }
-
-/** Result of applying an inbox action at the synchronous ownership boundary. */
-export type InboxActionResult = 'applied' | 'not-found'
-
-/**
- * Options for the unified {@link Agent.send} primitive over the
- * (`target` × `wakeup`) matrix. Named presets: {@link Agent.followup}
- * (`next-turn`/wakeup), {@link Agent.steer} (`next-step`/wakeup), and
- * {@link Agent.inject} (`next-step`/no-wakeup).
- *
- * The object is complete so routing policy is explicit.
- */
-export interface SendOptions {
-  /** Queue the item joins. */
-  target: SendTarget
-  /**
-   * Whether this item makes the model run: wake a parked driver (`next-turn`)
-   * or force a continuation step (`next-step` while running). A `false`
-   * `next-turn` item queues without waking; a `false`
-   * `next-step` item attaches durable context without forcing another step
-   * (the injection preset).
-   */
-  wakeup: boolean
-}
-
 /** Options for {@link Agent.cancel}. */
 export interface CancelOptions {
   /**
    * Preserve queued and steering inbox items instead of discarding them. The
    * active turn is still aborted, but un-started and pending work survives for a
-   * later turn and no `agent/inbox/canceled` fires.
+   * later turn and no canceled inbox splice is logged.
    */
   keepInbox?: boolean | undefined
 }
@@ -136,30 +85,13 @@ export interface Agent {
   readonly options: AgentOptions
   /** The live session this agent drives; its log is the durable source of truth. */
   readonly session: Session
+  /** The agent-owned projection of durable pending work. */
+  readonly inbox: Inbox
   /** The current lifecycle state, mirrored on every `agent/status` transition. */
   readonly status: AgentStatus
-  /** Whether a next-step send currently remains in the open turn. */
-  readonly acceptsNextStep: boolean
   /** Agent-scoped context; its contributions are agent-local, unwind on disposal, and reject registration afterward. */
   readonly ctx: Context
 
-  /**
-   * The unified delivery primitive over the (`target` × `wakeup`) matrix.
-   * @param message - identified model-facing content and its producer provenance.
-   * @param options - target queue and wakeup decision.
-   */
-  send(message: UserMessage, options: SendOptions): void
-
-  /**
-   * Mutate one still-pending queued occurrence synchronously. Editing preserves
-   * the message identity and queue position; removal publishes its terminal
-   * discard. Steering occurrences and driver-claimed items return `not-found`.
-   * @param id - independently addressable queued occurrence.
-   * @param action - edit or remove operation.
-   * @returns whether the pending occurrence was found and updated.
-   */
-  updateInbox(id: InboxItemId, action: InboxAction): InboxActionResult
-
   /**
    * Clear queued and steering work — unless `keepInbox` — and abort the active
    * turn. The first cause wins for the active turn. Idle cancellation is a
@@ -236,48 +168,6 @@ declare module 'cordis' {
      * @mode emit
      */
     'agent/status'(this: Scoped<Agent>, agent: Agent, status: AgentStatus): void
-    /**
-     * An item entered the queued or steering inbox. `placement` is the
-     * acceptance-time routing result.
-     * @param agent - the owning agent.
-     * @param item - accepted occurrence, message, and resolved placement.
-     * Scope-filtered dispatch (`@deepseek-ai/dsh-scope`): agent-scoped listeners receive only that agent.
-     * @mode emit
-     */
-    'agent/inbox/enqueue'(this: Scoped<Agent>, agent: Agent, item: InboxItem): void
-    /**
-     * A still-pending queued item changed content.
-     * @param agent - the owning agent.
-     * @param item - the complete post-update occurrence.
-     * Scope-filtered dispatch (`@deepseek-ai/dsh-scope`): agent-scoped listeners receive only that agent.
-     * @mode emit
-     */
-    'agent/inbox/update'(this: Scoped<Agent>, agent: Agent, item: InboxItem): void
-    /**
-     * The driver claimed one item out of the inbox.
-     * @param agent - the agent whose inbox item was claimed.
-     * @param item - the exact claimed occurrence.
-     * Scope-filtered dispatch (`@deepseek-ai/dsh-scope`): agent-scoped listeners receive only that agent.
-     * @mode emit
-     */
-    'agent/inbox/dequeue'(this: Scoped<Agent>, agent: Agent, item: InboxItem): void
-    /**
-     * Pending inbox items were dropped without delivery.
-     * @param agent - the agent whose inbox items were dropped.
-     * @param items - the discarded occurrences in FIFO order.
-     * Scope-filtered dispatch (`@deepseek-ai/dsh-scope`): agent-scoped listeners receive only that agent.
-     * @mode emit
-     */
-    'agent/inbox/discard'(this: Scoped<Agent>, agent: Agent, items: InboxItem[]): void
-    /**
-     * Effective broad cancellation was requested before pending work clears or
-     * the active turn aborts.
-     * @param agent - the agent whose current work is being cancelled.
-     * @param cause - the explicit typed cancellation cause.
-     * Scope-filtered dispatch (`@deepseek-ai/dsh-scope`): agent-scoped listeners receive only that agent.
-     * @mode emit
-     */
-    'agent/cancel-requested'(this: Scoped<Agent>, agent: Agent, cause: AgentCancelCause): void
     // ---- session lifecycle (emit) ----
     /**
      * The session lifecycle began, once before the first turn. Use
@@ -374,7 +264,13 @@ declare module 'cordis' {
 
 declare module '@deepseek-ai/dsh-session' {
   interface SessionEventMap {
-    /** One message was accepted into the agent inbox. */
-    'agent/inbox/added': UserMessage
+    /** One normalized mutation of an agent's durable pending-message lists. */
+    'agent/inbox/spliced': {
+      target: InboxTarget
+      start: number
+      removedCount?: number
+      inserted: UserMessage[]
+      outcome?: 'admitted' | 'canceled'
+    }
   }
 }
diff --git a/packages/core/agent/tests/agent.spec.ts b/packages/core/agent/tests/agent.spec.ts
index ffd1bd91c4..b2178aea7e 100644
--- a/packages/core/agent/tests/agent.spec.ts
+++ b/packages/core/agent/tests/agent.spec.ts
@@ -21,8 +21,6 @@ function stubAgent(rawId: string, overrides: Partial<Agent> = {}): Agent {
     session: new Session(id),
     status: 'idle',
     ctx: new Context(),
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject: () => {},
diff --git a/packages/core/agent/tests/invariant.spec.ts b/packages/core/agent/tests/invariant.spec.ts
index 7744726465..158376a3d7 100644
--- a/packages/core/agent/tests/invariant.spec.ts
+++ b/packages/core/agent/tests/invariant.spec.ts
@@ -1,7 +1,6 @@
-import { freezeMessage, MessageId } from '@deepseek-ai/dsh-llm'
 import { describe, expect, it } from 'vitest'
 import { Context } from 'cordis'
-import { InboxItemId, type Agent, type InboxItem, type InboxPlacement } from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
 import * as AgentInvariant from '@deepseek-ai/dsh-agent/invariant'
 import { scopeTarget } from '@deepseek-ai/dsh-scope'
 import InvariantService from '@deepseek-ai/dsh-invariants'
@@ -44,51 +43,3 @@ describe('agent status invariants', () => {
     expect(() => { ctx.emit(scopeTarget(b, b), 'agent/status', b, 'running') }).not.toThrow()
   })
 })
-
-describe('agent inbox invariants', () => {
-  let nextItem = 0
-  const info = (placement: InboxPlacement = 'queued'): InboxItem => ({
-    id: InboxItemId(`i-${nextItem++}`),
-    message: freezeMessage({
-      id: MessageId('m'),
-      role: 'user' as const,
-      content: [],
-      source: { kind: 'user' as const },
-    }),
-    placement,
-  })
-
-  it('accepts a dequeue and a discard covered by prior enqueues', async () => {
-    const ctx = await setup()
-    const agent = mockAgent('i1')
-    const at = scopeTarget(agent, agent)
-    expect(() => {
-      ctx.emit(at, 'agent/inbox/enqueue', agent, info())
-      ctx.emit(at, 'agent/inbox/enqueue', agent, info('steering'))
-      ctx.emit(at, 'agent/inbox/dequeue', agent, info())
-      ctx.emit(at, 'agent/inbox/discard', agent, [info()])
-    }).not.toThrow()
-  })
-
-  it('rejects a dequeue with no outstanding item', async () => {
-    const ctx = await setup()
-    const agent = mockAgent('i2')
-    expect(() => { ctx.emit(scopeTarget(agent, agent), 'agent/inbox/dequeue', agent, info()) })
-      .toThrow(/without a matching prior enqueue/)
-  })
-
-  it('rejects a discard larger than the outstanding count', async () => {
-    const ctx = await setup()
-    const agent = mockAgent('i3')
-    const at = scopeTarget(agent, agent)
-    ctx.emit(at, 'agent/inbox/enqueue', agent, info())
-    expect(() => { ctx.emit(at, 'agent/inbox/discard', agent, [info(), info()]) })
-      .toThrow(/dropped 2 items but only 1 were outstanding/)
-  })
-
-  it('accepts an empty discard against a fresh agent', async () => {
-    const ctx = await setup()
-    const agent = mockAgent('i4')
-    expect(() => { ctx.emit(scopeTarget(agent, agent), 'agent/inbox/discard', agent, []) }).not.toThrow()
-  })
-})
diff --git a/packages/core/agent/tsconfig.json b/packages/core/agent/tsconfig.json
index b6d6c9e6bf..1561175ed9 100644
--- a/packages/core/agent/tsconfig.json
+++ b/packages/core/agent/tsconfig.json
@@ -14,9 +14,6 @@
     {
       "path": "../../../vendor/cordis"
     },
-    {
-      "path": "../../util/brand"
-    },
     {
       "path": "../../core/scope"
     },
diff --git a/packages/core/scope/src/scoped-events.generated.ts b/packages/core/scope/src/scoped-events.generated.ts
index fff3107f48..e08fd2aabd 100644
--- a/packages/core/scope/src/scoped-events.generated.ts
+++ b/packages/core/scope/src/scoped-events.generated.ts
@@ -8,14 +8,9 @@
 type ScopedSubjectResolver = (args: readonly unknown[]) => unknown
 
 const scopedSubjectResolvers: Readonly<Record<string, ScopedSubjectResolver | null>> = Object.freeze({
-  'agent/cancel-requested': args => args[0],
   'agent/created': args => args[0],
   'agent/disposed': args => args[0],
   'agent/error': args => args[0],
-  'agent/inbox/dequeue': args => args[0],
-  'agent/inbox/discard': args => args[0],
-  'agent/inbox/enqueue': args => args[0],
-  'agent/inbox/update': args => args[0],
   'agent/prompt-submit': args => args[0],
   'agent/request': args => args[0],
   'agent/request-error': args => args[0],
diff --git a/packages/core/scope/tests/invariant.spec.ts b/packages/core/scope/tests/invariant.spec.ts
index f773f3a9aa..ccc90e7843 100644
--- a/packages/core/scope/tests/invariant.spec.ts
+++ b/packages/core/scope/tests/invariant.spec.ts
@@ -2,7 +2,7 @@ import { freezeMessage, MessageId } from '@deepseek-ai/dsh-llm'
 import { describe, expect, it } from 'vitest'
 import { Context } from 'cordis'
 import type { Events } from 'cordis'
-import { InboxItemId, type Agent } from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
 import { scopeTarget } from '@deepseek-ai/dsh-scope'
 import * as ScopeInvariant from '@deepseek-ai/dsh-scope/invariant'
 import InvariantService from '@deepseek-ai/dsh-invariants'
@@ -44,27 +44,22 @@ describe('scoped-dispatch invariants', () => {
       content: [],
       source: { kind: 'user' },
     })
-    const item = { id: InboxItemId('i'), message, placement: 'queued' as const }
     const agentRows = {
       'agent/created': [agent],
       'agent/disposed': [agent],
       'agent/status': [agent, 'idle'],
-      'agent/inbox/enqueue': [agent, item],
-      'agent/inbox/update': [agent, item],
-      'agent/inbox/dequeue': [agent, item],
-      'agent/inbox/discard': [agent, []],
       'agent/session-start': [agent, 'startup'],
       'agent/step': [agent, 1, 1, signal],
-      'agent/prompt-submit': [agent, message, signal, () => Promise.resolve({ kind: 'allow' })],
+      'agent/prompt-submit': [agent, [message], signal, () => Promise.resolve({ kind: 'allow', messages: [message] })],
       'agent/request': [agent, 1, 1, signal, () => Promise.resolve(config)],
       'agent/request-error': [
         agent,
-        1,
-        1,
-        new Error('request'),
-        { message: 'request', code: 'UNKNOWN' },
-        [],
-        undefined,
+        {
+          turn: 1,
+          step: 1,
+          provider: 'p',
+          failure: { message: 'request', code: 'UNKNOWN' },
+        },
         signal,
         () => Promise.resolve(undefined),
       ],
diff --git a/packages/examples/cli-demo/tests/cli.spec.ts b/packages/examples/cli-demo/tests/cli.spec.ts
index fc77b11331..1414a0691a 100644
--- a/packages/examples/cli-demo/tests/cli.spec.ts
+++ b/packages/examples/cli-demo/tests/cli.spec.ts
@@ -114,14 +114,13 @@ const liveContexts: Context[] = []
 
 async function harness(script: readonly ScriptEntry[]): Promise<Harness> {
   const root = await mkdtemp(join(tmpdir(), 'dsh-cli-runner-'))
-  const skillHome = await mkdtemp(join(tmpdir(), 'dsh-cli-runner-skills-'))
   const ctx = new Context()
   liveContexts.push(ctx)
   await ctx.plugin(cliDemo, {
     provider: 'mock',
     model: 'mock',
     persistenceRoot: root,
-    skills: { local: { dshHome: join(skillHome, '.dsh'), agentsHome: join(skillHome, '.agents') } },
+    skills: { enabled: false },
     workspaceContext: false,
   })
   await new Promise(resolve => setTimeout(resolve, 80))
@@ -380,29 +379,94 @@ describe('runOneShot and executeCli', () => {
     expect(result.result).toBe('working')
   })
 
-  it('streams only the correlated main message turn and then the result envelope', async () => {
-    const { ctx, agent } = await harness([textResponse('streamed')])
+  it('observes only the correlated main message turn', async () => {
+    const { ctx, agent } = await harness([
+      textResponse('startup'),
+      textResponse('autonomous'),
+      textResponse('streamed'),
+    ])
     const other = ctx.sessions.create(SessionId('unrelated'))
-    let injected = false
-    ctx.on('agent/inbox/enqueue', (subject) => {
-      if (subject !== agent || injected) return
-      injected = true
-      agent.inject(createUserMessage({ content: [{ type: 'text', text: 'startup injection' }], source: { kind: 'plugin', plugin: 'test' } }))
+    let startupStarted!: () => void
+    const started = new Promise<void>((resolve) => { startupStarted = resolve })
+    const releaseStartup = Promise.withResolvers<undefined>()
+    ctx.on('session/event', (session, event) => {
+      if (session === agent.session && event.type === 'assistant/message'
+        && event.data.turn === 1) startupStarted()
+    })
+    ctx.on('agent/turn-stopping', async (subject, turn) => {
+      if (subject === agent && turn === 1) await releaseStartup.promise
+    })
+    agent.followup(createUserMessage({
+      content: [{ type: 'text', text: 'startup' }],
+      source: { kind: 'plugin', plugin: 'startup' },
+    }))
+    await started
+
+    let replacementQueued = false
+    ctx.on('agent/status', (subject, status) => {
+      if (subject !== agent || status !== 'idle' || replacementQueued) return
+      replacementQueued = true
+      agent.followup(createUserMessage({
+        content: [{ type: 'text', text: 'autonomous' }],
+        source: { kind: 'plugin', plugin: 'test' },
+      }))
       other.append('turn/start', { turn: 1 })
       other.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
     })
-    const output = await invoke(ctx, ['--output-format', 'stream-json', 'task'])
-    const lines = output.stdout.trimEnd().split('\n').map(line => JSON.parse(line) as Record<string, unknown>)
-    const events = lines.slice(0, -1).map(line => line['event'] as SessionEvent)
-    expect(lines.at(-1)).toMatchObject({ type: 'result', success: true, turn: 1, result: 'streamed' })
-    expect(events[0]).toMatchObject({ type: 'turn/start', data: { turn: 1 } })
-    expect(events.at(-1)).toMatchObject({ type: 'turn/end', data: { turn: 1 } })
-    expect(lines.slice(0, -1).every(line => line['sessionId'] === agent.session.id)).toBe(true)
+    const streamed: { sessionId: string; event: SessionEvent }[] = []
+    const result = runOneShot(ctx, {
+      task: 'task',
+      onEvent: (sessionId, event) => { streamed.push({ sessionId, event }) },
+    })
+    releaseStartup.resolve(undefined)
+
+    const outcome = await result
+    expect(outcome.reason).toEqual({ kind: 'completed' })
+    expect(outcome).toMatchObject({ success: true, turn: 3, result: 'streamed' })
+    const events = streamed.map(item => item.event)
+    expect(events[0]).toMatchObject({ type: 'turn/start', data: { turn: 3 } })
+    expect(events.at(-1)).toMatchObject({ type: 'turn/end', data: { turn: 3 } })
+    expect(streamed.every(item => item.sessionId === agent.session.id)).toBe(true)
     expect(events.some(event => event.type === 'user/message'
       && event.data.source.kind === 'plugin'
       && event.data.source.plugin === 'test')).toBe(false)
   })
 
+  it('correlates a task whose admitted history is replaced', async () => {
+    const { ctx } = await harness([textResponse('rewritten answer')])
+    ctx.on('agent/prompt-submit', async () => ({
+      kind: 'allow',
+      messages: [createUserMessage({
+        content: [{ type: 'text', text: 'rewritten task' }],
+        source: { kind: 'plugin', plugin: 'test' },
+      })],
+    }))
+
+    await expect(runOneShot(ctx, { task: 'original task' })).resolves.toMatchObject({
+      success: true,
+      result: 'rewritten answer',
+    })
+  })
+
+  it('rejects tasks blocked before admission, including retained tasks', async () => {
+    const blocked = await harness([])
+    blocked.ctx.on('agent/prompt-submit', async () => ({ kind: 'block' as const, reason: 'denied' }))
+    await expect(runOneShot(blocked.ctx, { task: 'task' })).rejects.toThrow('canceled before admission')
+
+    const retained = await harness([])
+    retained.ctx.on('agent/prompt-submit', async () => ({
+      kind: 'block' as const,
+      reason: 'deferred',
+      keepInbox: true,
+    }))
+    await expect(runOneShot(retained.ctx, { task: 'task' })).rejects.toThrow('not admitted')
+    expect(retained.agent.status).toBe('idle')
+
+    const failed = await harness([])
+    failed.ctx.on('agent/prompt-submit', async () => { throw new Error('admission exploded') })
+    await expect(runOneShot(failed.ctx, { task: 'task' })).rejects.toThrow('not admitted')
+  })
+
   it('emits partial data and a diagnostic for non-completed turns', async () => {
     const { ctx } = await harness([textResponse('partial', { inputTokens: 2, outputTokens: 3 }, 'max-tokens')])
     const output = await invoke(ctx, ['--output-format', 'json', 'task'])
@@ -498,8 +562,11 @@ describe('runOneShot and executeCli', () => {
 
     const queued = await harness([textResponse('unused')])
     const queuedAbort = new AbortController()
-    queued.ctx.on('agent/inbox/enqueue', (agent) => {
-      if (agent === queued.agent) queuedAbort.abort('cancel queued')
+    queued.ctx.on('session/event', (session, event) => {
+      if (session === queued.agent.session && event.type === 'agent/inbox/spliced'
+        && event.data.inserted.some(message => message.source.kind === 'user')) {
+        queueMicrotask(() => { queuedAbort.abort('cancel queued') })
+      }
     })
     await expect(runOneShot(queued.ctx, { task: 'task', signal: queuedAbort.signal })).rejects.toThrow('cancel queued')
     await queued.agent.whenIdle()
diff --git a/packages/goal/command-goal/tests/command-goal.spec.ts b/packages/goal/command-goal/tests/command-goal.spec.ts
index 89f115df4d..ef7204e7c0 100644
--- a/packages/goal/command-goal/tests/command-goal.spec.ts
+++ b/packages/goal/command-goal/tests/command-goal.spec.ts
@@ -36,9 +36,6 @@ function stubAgent(ctx: Context, id: string): { agent: Agent; session: Session }
     session,
     ctx: new Context(),
     get status() { return status },
-    get acceptsNextStep() { return status === 'running' },
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject(input) { appendInjection(session, input) },
diff --git a/packages/goal/goal-session/src/index.ts b/packages/goal/goal-session/src/index.ts
index 3260016d5f..5694da1dae 100644
--- a/packages/goal/goal-session/src/index.ts
+++ b/packages/goal/goal-session/src/index.ts
@@ -324,37 +324,6 @@ export function apply(ctx: Context): void {
         requestDrive(state)
       }
     })
-    ctx.on('agent/inbox/enqueue', (agent, item) => {
-      const state = stateFor(agent)
-      const attempt = state.attempt
-      if (attempt !== undefined && sameQueued(item.message.content, item.message.source, attempt)) return
-      state.competingQueued = true
-      if (attempt?.phase === 'queued') attempt.stale = true
-    })
-    ctx.on('agent/cancel-requested', (agent, cause) => {
-      const state = stateFor(agent)
-      const attempt = state.attempt
-      state.competingQueued = false
-      const goal = currentGoal(state)
-      if (goal?.phase === 'active' && goal.activation === 'armed') {
-        if (attempt === undefined) {
-          disarm(state)
-          return
-        }
-        // An admitted round closes durably as aborted; retain it so the normal
-        // turn outcome path appends pause after cancellation reaches idle.
-        // Pausing here would stage context into the active outbox only for this
-        // same cancel() call to discard it.
-        if (attempt.turn !== undefined || attempt.phase === 'admitted') return
-        state.attempt = undefined
-        try {
-          applyOutcome(state, goal, { kind: 'pause', reason: cause.kind })
-        } catch (error: unknown) {
-          ctx.logger.warn(`goal-session: could not pause cancelled goal for agent "${agent.id}": ${renderThrown(error)}`)
-          disarm(state)
-        }
-      }
-    })
     ctx.on('goal/changed', (agent) => {
       const state = stateFor(agent)
       state.needsCheckpoint = true
@@ -366,12 +335,14 @@ export function apply(ctx: Context): void {
       if (agent === undefined || agent.session !== session) return
       const state = stateFor(agent)
       switch (event.type) {
-        case 'agent/inbox/added': {
+        case 'agent/inbox/spliced': {
+          if (event.data.target !== 'next-turn') return
           const attempt = state.attempt
-          const { content, source } = event.data
-          if (attempt !== undefined && sameQueued(content, source, attempt)) return
-          state.competingQueued = true
-          if (attempt?.phase === 'queued') attempt.stale = true
+          for (const message of event.data.inserted) {
+            if (attempt !== undefined && sameQueued(message.content, message.source, attempt)) continue
+            state.competingQueued = true
+            if (attempt?.phase === 'queued') attempt.stale = true
+          }
           return
         }
         case 'turn/start': {
diff --git a/packages/goal/goal-session/tests/goal-session.spec.ts b/packages/goal/goal-session/tests/goal-session.spec.ts
index 20c74b9f15..d1144bea1d 100644
--- a/packages/goal/goal-session/tests/goal-session.spec.ts
+++ b/packages/goal/goal-session/tests/goal-session.spec.ts
@@ -9,7 +9,7 @@ import type { GoalView } from '@deepseek-ai/dsh-goal'
 import { createUserMessage, LlmAdapter, LlmError  } from '@deepseek-ai/dsh-llm'
 import type { GenerateOptions, StreamChunk } from '@deepseek-ai/dsh-llm'
 import { SessionId } from '@deepseek-ai/dsh-session'
-import type { TurnEndReason } from '@deepseek-ai/dsh-session'
+import type { TurnEndReason, UserMessage } from '@deepseek-ai/dsh-session'
 import * as goalSession from '../src/index.ts'
 
 type ScriptEntry = StreamChunk[] | Error | 'hang' | ((options: GenerateOptions) => StreamChunk[])
@@ -101,6 +101,18 @@ async function harness(script: ScriptEntry[]): Promise<Harness> {
   return { ctx, adapter, agent, driver }
 }
 
+/** Observe inserted inbox messages after the session append boundary closes. */
+function onInboxMessage(
+  ctx: Context,
+  agent: Agent,
+  listener: (message: UserMessage) => void,
+): () => void {
+  return ctx.on('session/event', (session, event) => {
+    if (session !== agent.session || event.type !== 'agent/inbox/spliced') return
+    for (const message of event.data.inserted) queueMicrotask(() => { listener(message) })
+  })
+}
+
 /** Await a stable goal projection selected by the caller. */
 async function waitForGoal(
   ctx: Context,
@@ -279,10 +291,10 @@ describe('same-session goal driving', () => {
 
   it('pauses and drops a reserved round when cancellation lands before admission', async () => {
     const test = await harness([])
-    const cancel = test.ctx.on('agent/inbox/enqueue', (agent, info) => {
-      if (agent === test.agent && info.message.source.kind === 'goal') {
+    const cancel = onInboxMessage(test.ctx, test.agent, (message) => {
+      if (message.source.kind === 'goal') {
         cancel()
-        agent.cancel({ kind: 'user' })
+        test.agent.cancel({ kind: 'user' })
       }
     })
     test.ctx.goals.create(test.agent, { objective: 'do not start yet' })
@@ -330,10 +342,10 @@ describe('same-session goal driving', () => {
   it('makes a reserved round stale when a listener queues human work behind it', async () => {
     const test = await harness([textResponse('human batch'), textResponse('later goal')])
     let inserted = false
-    test.ctx.on('agent/inbox/enqueue', (agent, info) => {
-      if (agent !== test.agent || info.message.source.kind !== 'goal' || inserted) return
+    onInboxMessage(test.ctx, test.agent, (message) => {
+      if (message.source.kind !== 'goal' || inserted) return
       inserted = true
-      agent.followup(createUserMessage({ content: [{ type: 'text', text: 'human joined the pending batch' }], source: { kind: 'user' } }))
+      test.agent.followup(createUserMessage({ content: [{ type: 'text', text: 'human joined the pending batch' }], source: { kind: 'user' } }))
     })
     test.ctx.goals.create(test.agent, { objective: 'yield to nested human input', maxGoalRounds: 1 })
 
@@ -348,12 +360,12 @@ describe('same-session goal driving', () => {
   it('blocks a queued reservation made stale by a goal edit and continues the new revision', async () => {
     const test = await harness([textResponse('new revision')])
     let edited = false
-    test.ctx.on('agent/inbox/enqueue', (agent, info) => {
-      if (agent !== test.agent || info.message.source.kind !== 'goal' || edited) return
+    onInboxMessage(test.ctx, test.agent, (message) => {
+      if (message.source.kind !== 'goal' || edited) return
       edited = true
-      const current = test.ctx.goals.get(agent)
+      const current = test.ctx.goals.get(test.agent)
       if (current === undefined) throw new Error('missing goal during queued edit')
-      test.ctx.goals.edit(agent, current, { objective: 'new objective' })
+      test.ctx.goals.edit(test.agent, current, { objective: 'new objective' })
     })
     test.ctx.goals.create(test.agent, { objective: 'old objective', maxGoalRounds: 1 })
 
@@ -628,8 +640,8 @@ describe('same-session goal driving', () => {
   it('fails a pre-admission read closed even when the first disarm attempt throws', async () => {
     const test = await harness([textResponse('retry after containment')])
     let armed = true
-    test.ctx.on('agent/inbox/enqueue', (agent, info) => {
-      if (agent !== test.agent || info.message.source.kind !== 'goal' || !armed) return
+    onInboxMessage(test.ctx, test.agent, (message) => {
+      if (message.source.kind !== 'goal' || !armed) return
       armed = false
       vi.spyOn(test.ctx.goals, 'get').mockImplementationOnce(() => {
         throw new Error('admission projection failed')
@@ -704,13 +716,13 @@ describe('same-session goal driving', () => {
 
   it('falls back to disarming when a cancelled reservation cannot be paused', async () => {
     const test = await harness([])
-    const cancel = test.ctx.on('agent/inbox/enqueue', (agent, info) => {
-      if (agent !== test.agent || info.message.source.kind !== 'goal') return
+    const cancel = onInboxMessage(test.ctx, test.agent, (message) => {
+      if (message.source.kind !== 'goal') return
       cancel()
       vi.spyOn(test.ctx.goals, 'pause').mockImplementationOnce(() => {
         throw new Error('pause failed')
       })
-      agent.cancel({ kind: 'user' })
+      test.agent.cancel({ kind: 'user' })
     })
     test.ctx.goals.create(test.agent, { objective: 'fail closed after cancellation' })
 
@@ -758,8 +770,8 @@ describe('same-session goal driving', () => {
   it('cancels an accepted queued round and awaits its driver task during teardown', async () => {
     const test = await harness([])
     let unloading: Promise<void> | undefined
-    test.ctx.on('agent/inbox/enqueue', (agent, info) => {
-      if (agent === test.agent && info.message.source.kind === 'goal' && unloading === undefined) {
+    onInboxMessage(test.ctx, test.agent, (message) => {
+      if (message.source.kind === 'goal' && unloading === undefined) {
         unloading = Promise.resolve(test.driver.dispose())
       }
     })
diff --git a/packages/goal/goal/tests/goal.spec.ts b/packages/goal/goal/tests/goal.spec.ts
index e01356f271..f395996011 100644
--- a/packages/goal/goal/tests/goal.spec.ts
+++ b/packages/goal/goal/tests/goal.spec.ts
@@ -46,9 +46,6 @@ function stubAgentForSession(session: Session): StubAgent {
     session,
     ctx: new Context(),
     get status() { return status },
-    get acceptsNextStep() { return status === 'running' },
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject(input) {
diff --git a/packages/goal/goal/tests/projection.spec.ts b/packages/goal/goal/tests/projection.spec.ts
index f787a881f8..70fcbc0d5a 100644
--- a/packages/goal/goal/tests/projection.spec.ts
+++ b/packages/goal/goal/tests/projection.spec.ts
@@ -37,9 +37,6 @@ function liveAgent(ctx: Context, session: Session): Agent {
     session,
     ctx,
     get status() { return status },
-    get acceptsNextStep() { return false },
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject(input: UserMessage) {
diff --git a/packages/goal/tool-goal/tests/tool-goal.spec.ts b/packages/goal/tool-goal/tests/tool-goal.spec.ts
index 7bcee0c0e7..d411e0c9b2 100644
--- a/packages/goal/tool-goal/tests/tool-goal.spec.ts
+++ b/packages/goal/tool-goal/tests/tool-goal.spec.ts
@@ -30,10 +30,7 @@ function stubAgent(rawId: string, supplied?: Session): StubAgent {
     options: {},
     session,
     get status() { return status },
-    get acceptsNextStep() { return status === 'running' },
     ctx: new Context(),
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject(input) {
diff --git a/packages/host/apiproxy/src/api-proxy.ts b/packages/host/apiproxy/src/api-proxy.ts
index e7c1d96acf..c68f81745d 100644
--- a/packages/host/apiproxy/src/api-proxy.ts
+++ b/packages/host/apiproxy/src/api-proxy.ts
@@ -9,9 +9,9 @@ import { join } from 'node:path'
 import type { Context } from 'cordis'
 import { installAgentLlmTarget } from '@deepseek-ai/dsh-agent'
 import type {
-  Agent, AgentLlmTarget, AgentLlmTargetRef, AgentStatus, InboxItem, InboxItemId,
+  Agent, AgentLlmTarget, AgentLlmTargetRef, AgentStatus,
 } from '@deepseek-ai/dsh-agent'
-import { createUserMessage, ReasoningEffortId } from '@deepseek-ai/dsh-llm'
+import { createUserMessage, freezeMessage, ReasoningEffortId } from '@deepseek-ai/dsh-llm'
 import { errorChain } from '@deepseek-ai/dsh-llm'
 import type { MessageSource } from '@deepseek-ai/dsh-llm'
 import type { Session, SessionEvent, SessionHeader, SessionId, UserMessage } from '@deepseek-ai/dsh-session'
@@ -507,112 +507,6 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
     })
   })
 
-  /**
-   * Per-session queued-occurrence mirror serving the mux-open queue snapshot
-   * (the same refresh-recovery baseline as pending questions). Each terminal
-   * queue event retires one matching occurrence, so repeated sends of the same
-   * identified message remain visible until every occurrence is claimed.
-   */
-  const queuedMirror = new Map<SessionId, InboxItem[]>()
-  type UnseenQueueEvent =
-    | { readonly kind: 'update'; readonly item: InboxItem }
-    | { readonly kind: 'terminal' }
-  const unseenQueueEvents = new Map<SessionId, Map<InboxItemId, UnseenQueueEvent>>()
-  const rememberUnseen = (sessionId: SessionId, itemId: InboxItemId, event: UnseenQueueEvent): void => {
-    let events = unseenQueueEvents.get(sessionId)
-    if (events === undefined) {
-      events = new Map()
-      unseenQueueEvents.set(sessionId, events)
-    }
-    events.set(itemId, event)
-    // Only synchronous re-entrancy may deliver a mutation before its outer
-    // enqueue observer. Drop unmatched protocol-invalid observations instead
-    // of retaining process-local ids indefinitely.
-    queueMicrotask(() => {
-      const current = unseenQueueEvents.get(sessionId)
-      if (current?.get(itemId) !== event) return
-      current.delete(itemId)
-      if (current.size === 0) unseenQueueEvents.delete(sessionId)
-    })
-  }
-  const takeUnseen = (sessionId: SessionId, itemId: InboxItemId): UnseenQueueEvent | undefined => {
-    const events = unseenQueueEvents.get(sessionId)
-    const event = events?.get(itemId)
-    if (event === undefined) return undefined
-    events?.delete(itemId)
-    if (events?.size === 0) unseenQueueEvents.delete(sessionId)
-    return event
-  }
-  const publishQueue = (sessionId: SessionId): void => {
-    const items = queuedMirror.get(sessionId) ?? []
-    broadcast({
-      type: 'session/queue',
-      sessionId,
-      items: items.map(item => ({
-        id: item.id,
-        message: item.message,
-      })),
-    })
-  }
-  ctx.effect(() => {
-    const retire = (agent: Agent, item: InboxItem): boolean => {
-      const entries = queuedMirror.get(agent.id)
-      if (entries === undefined) {
-        rememberUnseen(agent.id, item.id, { kind: 'terminal' })
-        return false
-      }
-      const index = entries.findIndex(entry => entry.id === item.id)
-      if (index === -1) {
-        rememberUnseen(agent.id, item.id, { kind: 'terminal' })
-        return false
-      }
-      entries.splice(index, 1)
-      if (entries.length === 0) queuedMirror.delete(agent.id)
-      return true
-    }
-    const disposers = [
-      ctx.on('agent/inbox/enqueue', (agent: Agent, item: InboxItem) => {
-        if (item.placement !== 'queued') return
-        const unseen = takeUnseen(agent.id, item.id)
-        if (unseen?.kind === 'terminal') return
-        let entries = queuedMirror.get(agent.id)
-        if (entries === undefined) {
-          entries = []
-          queuedMirror.set(agent.id, entries)
-        }
-        entries.push(unseen?.kind === 'update' ? unseen.item : item)
-        publishQueue(agent.id)
-      }),
-      ctx.on('agent/inbox/update', (agent: Agent, item: InboxItem) => {
-        const entries = queuedMirror.get(agent.id)
-        if (entries === undefined) {
-          rememberUnseen(agent.id, item.id, { kind: 'update', item })
-          return
-        }
-        const index = entries.findIndex(entry => entry.id === item.id)
-        if (index === -1) {
-          rememberUnseen(agent.id, item.id, { kind: 'update', item })
-          return
-        }
-        entries.splice(index, 1, item)
-        publishQueue(agent.id)
-      }),
-      ctx.on('agent/inbox/dequeue', (agent: Agent, item: InboxItem) => {
-        if (retire(agent, item)) publishQueue(agent.id)
-      }),
-      ctx.on('agent/inbox/discard', (agent: Agent, items: InboxItem[]) => {
-        let changed = false
-        for (const item of items) changed = retire(agent, item) || changed
-        if (changed) publishQueue(agent.id)
-      }),
-      ctx.on('session/disposed', (session: Session) => {
-        queuedMirror.delete(session.id)
-        unseenQueueEvents.delete(session.id)
-      }),
-    ]
-    return () => { for (const dispose of disposers) dispose() }
-  }, 'api-proxy: queued mirror')
-
   /** Remove a wait before settling it: synchronous deletion makes the first claimant win. */
   function claimQuestion(pending: PendingQuestion, outcome: 'answered' | 'cancelled'): void {
     pendingQuestions.delete(pending.rpcId)
@@ -1162,13 +1056,21 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
       updateQueue(request) {
         const { sessionId, itemId, action } = request.payload
         const agent = ctx.agents.get(sessionId)
-        if (agent === undefined || agent.updateInbox(itemId, action) === 'not-found') {
+        const queued = agent?.inbox.nextTurn
+        const index = queued?.findIndex(message => message.id === itemId) ?? -1
+        const message = queued?.[index]
+        if (agent === undefined || message === undefined) {
           return Promise.resolve(err(request, {
             code: 'queue-item-not-found',
             message: 'queued item is no longer pending',
             details: { itemId },
           }))
         }
+        if (action.kind === 'edit') {
+          agent.inbox.splice('next-turn', index, 1, [freezeMessage({ ...message, content: action.content })])
+        } else {
+          agent.inbox.splice('next-turn', index, 1, [])
+        }
         return Promise.resolve(ok(request, { accepted: true as const }))
       },
 
@@ -1567,14 +1469,13 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
         // Queue snapshot baseline (pendingQuestions precedent): frames replayed
         // in arrival order per session; a reconnecting client rebuilds its
         // queue view from these alone.
-        for (const [sessionId, items] of queuedMirror) {
+        for (const agent of ctx.agents.list()) {
+          const items = agent.inbox.nextTurn
+          if (items.length === 0) continue
           queue.push(frame({
             type: 'session/queue',
-            sessionId,
-            items: items.map(item => ({
-              id: item.id,
-              message: item.message,
-            })),
+            sessionId: agent.id,
+            items: [...items],
           }))
         }
         // Per-session open-call table for result-view pairing. Bounded by the
diff --git a/packages/host/apiproxy/src/api/events.schema.ts b/packages/host/apiproxy/src/api/events.schema.ts
index 4e17b1f403..040540d830 100644
--- a/packages/host/apiproxy/src/api/events.schema.ts
+++ b/packages/host/apiproxy/src/api/events.schema.ts
@@ -11,7 +11,7 @@ import type { Wire } from './rpc.schema.ts'
 import { rpcErrorSchema, rpcIdSchema } from './rpc.schema.ts'
 import { approvalRequestIdSchema } from './approvals.schema.ts'
 import {
-  contentBlockSchema, inboxItemIdSchema, sessionEventSchema, sessionIdSchema, toolEventViewSchema,
+  contentBlockSchema, messageIdSchema, sessionEventSchema, sessionIdSchema, toolEventViewSchema,
 } from './sessions.schema.ts'
 import { workspaceIdSchema, workspaceViewSchema } from './workspace.schema.ts'
 
@@ -25,10 +25,10 @@ export const askUserQuestionItemSchema = z.object({
   multiSelect: z.boolean().optional(),
 }) satisfies z.ZodType<Wire<AskUserQuestionItem>>
 
-/** Unified message envelope carried by transient queue frames. */
-const messageSchema = z.object({
-  id: z.string().min(1),
-  role: z.union([z.literal('system'), z.literal('user'), z.literal('assistant')]),
+/** User-message envelope carried by queue baselines. */
+const userMessageSchema = z.object({
+  id: messageIdSchema,
+  role: z.literal('user'),
   content: z.array(contentBlockSchema),
   source: z.looseObject({ kind: z.string() }),
 })
@@ -47,10 +47,7 @@ export const muxFrameSchema = z.discriminatedUnion('type', [
   z.object({
     type: z.literal('session/queue'),
     sessionId: sessionIdSchema,
-    items: z.array(z.object({
-      id: inboxItemIdSchema,
-      message: messageSchema,
-    })),
+    items: z.array(userMessageSchema),
   }),
   // value stays wide: it already passed its unit's own schema on the host,
   // and deep-validating here would import every domain's schema into the carrier.
diff --git a/packages/host/apiproxy/src/api/events.ts b/packages/host/apiproxy/src/api/events.ts
index ad541b4e4d..859f4e1bc2 100644
--- a/packages/host/apiproxy/src/api/events.ts
+++ b/packages/host/apiproxy/src/api/events.ts
@@ -8,9 +8,8 @@
 
 import type { AskUserQuestionItem } from '@deepseek-ai/dsh-user-interaction/types'
 import type { ApprovalOutcome, ApprovalRequestId } from '@deepseek-ai/dsh-user-approval/types'
-import type { Message } from '@deepseek-ai/dsh-llm/types'
-import type { InboxItemId } from '@deepseek-ai/dsh-agent/brand'
 import type { CallId } from '@deepseek-ai/dsh-llm/brand'
+import type { UserMessage } from '@deepseek-ai/dsh-llm/message'
 import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
 import type { ToolCallView, ToolResultView } from '@deepseek-ai/dsh-tools/presentation'
 import type { RpcError, RpcId, RpcRequest } from './rpc.ts'
@@ -32,14 +31,6 @@ export type ToolEventView =
   | { for: 'call'; view: ToolCallView }
   | { for: 'result'; view: ToolResultView }
 
-/** One pending queued occurrence in an authoritative queue snapshot. */
-export interface QueuedInboxItem {
-  /** Agent-owned occurrence identity used by queue mutations. */
-  id: InboxItemId
-  /** Complete pending message; it is not durable until the Agent claims it. */
-  message: Message
-}
-
 /** Streaming face of the contract: the two SSE stream openers (mux + host). */
 export interface EventsApi {
   /**
@@ -71,13 +62,11 @@ export type MuxFrame =
   | { type: 'question/requested'; sessionId: SessionId; questions: AskUserQuestionItem[] }
   | { type: 'question/resolved'; sessionId: SessionId; questionRpcId: RpcId; outcome: 'answered' | 'cancelled' }
   /**
-   * Complete transient queue state after every enqueue, mutation, claim, or
-   * discard. Pending work is not model-visible and therefore has no durable
-   * session event; the whole snapshot makes edit, deletion, cancel, and
-   * reconnect converge through one authoritative signal. Pending steering is
-   * outside this Web queue projection.
+   * Complete next-turn queue baseline emitted when a mux stream opens. Live
+   * mutations arrive through durable `agent/inbox/spliced` session events.
+   * Pending next-step input is outside this Web queue projection.
    */
-  | { type: 'session/queue'; sessionId: SessionId; items: QueuedInboxItem[] }
+  | { type: 'session/queue'; sessionId: SessionId; items: UserMessage[] }
   /**
    * One projection unit's finished value changed (session-projection RFC).
    * Live push state, never logged — replay recomputes on the host (the
diff --git a/packages/host/apiproxy/src/api/index.ts b/packages/host/apiproxy/src/api/index.ts
index 0372c8cc30..a89f6db2ea 100644
--- a/packages/host/apiproxy/src/api/index.ts
+++ b/packages/host/apiproxy/src/api/index.ts
@@ -35,7 +35,7 @@ export type { DirectoryEntry, DirectoryListing, HostApi } from './host.ts'
 export type { WorkspaceApi, WorkspaceId, WorkspaceView } from './workspace.ts'
 export type { CommandsApi, CommandDescriptor } from './commands.ts'
 export type { SkillsApi, SkillEntry } from './skills.ts'
-export type { EventsApi, MuxFrame, HostFrame, QueuedInboxItem, ToolCallView, ToolEventView, ToolResultView } from './events.ts'
+export type { EventsApi, MuxFrame, HostFrame, ToolCallView, ToolEventView, ToolResultView } from './events.ts'
 export type { GoalsApi, GoalId, GoalRef } from './goals.ts'
 export type { ApprovalResponsePayload } from './approvals.ts'
 export type { QuestionResponsePayload } from './questions.ts'
@@ -56,7 +56,5 @@ export type {
 // ---- Errors and ids ----
 export { RpcId, transportError } from './rpc.ts'
 export type { RpcError, RpcErrorCode, RpcErrorDetailsMap, RpcResult } from './rpc.ts'
-export type { InboxItemId } from '@deepseek-ai/dsh-agent/brand'
-
 // ---- Method registry and derived generics ----
 export type { RequestPayload, ResponseValue, RpcMethodMap } from './rpc-map.ts'
diff --git a/packages/host/apiproxy/src/api/rpc.ts b/packages/host/apiproxy/src/api/rpc.ts
index c1fa4e1611..2c27ee16f2 100644
--- a/packages/host/apiproxy/src/api/rpc.ts
+++ b/packages/host/apiproxy/src/api/rpc.ts
@@ -8,8 +8,8 @@
 import type { z as zCore } from 'zod'
 type ZodIssue = zCore.core.$ZodIssue
 import type { Branded } from '@deepseek-ai/dsh-brand'
+import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
 import type { SessionId } from '@deepseek-ai/dsh-session/types'
-import type { InboxItemId } from '@deepseek-ai/dsh-agent/brand'
 
 /**
  * Message correlation id: the initiator mints it on a request; a response
@@ -45,7 +45,7 @@ export interface RpcErrorDetailsMap {
   'directory-create-failed': { path: string }
   'directory-picker-unavailable': { capability: string }
   'agent-busy': { reason: string }
-  'queue-item-not-found': { itemId: InboxItemId }
+  'queue-item-not-found': { itemId: MessageId }
   /** A known slash command reported a usage/state error; the message is the command's own text. */
   'command-error': {}
   /** A leading-/ prompt named no registered command; the message names the token. */
diff --git a/packages/host/apiproxy/src/api/sessions.schema.ts b/packages/host/apiproxy/src/api/sessions.schema.ts
index e3744ec37a..6b64b80d81 100644
--- a/packages/host/apiproxy/src/api/sessions.schema.ts
+++ b/packages/host/apiproxy/src/api/sessions.schema.ts
@@ -7,7 +7,7 @@
 
 import { z } from 'zod'
 import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
-import type { InboxItemId } from '@deepseek-ai/dsh-agent/brand'
+import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
 import type { RequestPayload, ResponseValue } from './rpc-map.ts'
 import type { Wire } from './rpc.schema.ts'
 import type {
@@ -20,8 +20,8 @@ import type { WorkspaceId } from './workspace.ts'
 /** SessionId: one brand cast after shape validation (the only cast point in this domain). */
 export const sessionIdSchema = z.string().min(1) as unknown as z.ZodType<SessionId>
 
-/** InboxItemId: one brand cast after non-empty string validation. */
-export const inboxItemIdSchema = z.string().min(1) as unknown as z.ZodType<InboxItemId>
+/** MessageId: one brand cast after non-empty string validation. */
+export const messageIdSchema = z.string().min(1) as unknown as z.ZodType<MessageId>
 
 /**
  * WorkspaceId: the workspace domain's one brand cast. Hosted here rather
@@ -221,7 +221,7 @@ export const sessionPromptValueSchema = z.object({
 /** session.updateQueue request payload. */
 export const sessionUpdateQueueRequestSchema = z.object({
   sessionId: sessionIdSchema,
-  itemId: inboxItemIdSchema,
+  itemId: messageIdSchema,
   action: z.discriminatedUnion('kind', [
     z.object({ kind: z.literal('edit'), content: z.array(contentBlockSchema) }),
     z.object({ kind: z.literal('remove') }),
diff --git a/packages/host/apiproxy/src/api/sessions.ts b/packages/host/apiproxy/src/api/sessions.ts
index a57c3f4b73..eac40ffbf3 100644
--- a/packages/host/apiproxy/src/api/sessions.ts
+++ b/packages/host/apiproxy/src/api/sessions.ts
@@ -4,8 +4,8 @@
  * else references RequestPayload<'session.*'> / ResponseValue<'session.*'>.
  */
 
+import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
-import type { InboxItemId } from '@deepseek-ai/dsh-agent/brand'
 import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
 // The pure-type outlet: api/ is browser-importable, and the package root's
 // cordis Context merge (via dsh-agent) must not enter client aggregates.
@@ -238,7 +238,7 @@ export interface SessionsApi {
   /**
    * Edits or removes one pending queued occurrence.
    */
-  updateQueue(request: RpcRequest<{ sessionId: SessionId; itemId: InboxItemId; action: QueueAction }>):
+  updateQueue(request: RpcRequest<{ sessionId: SessionId; itemId: MessageId; action: QueueAction }>):
   Promise<RpcResponse<{ accepted: true }>>
 
   /** Stops: clears both FIFOs + aborts the current step (1:1 with agent.cancel). */
diff --git a/packages/host/apiproxy/tests/api-proxy-commands.spec.ts b/packages/host/apiproxy/tests/api-proxy-commands.spec.ts
index 6df71258be..73a3a793e6 100644
--- a/packages/host/apiproxy/tests/api-proxy-commands.spec.ts
+++ b/packages/host/apiproxy/tests/api-proxy-commands.spec.ts
@@ -11,8 +11,8 @@ import { MessageId, freezeMessage } from '@deepseek-ai/dsh-llm'
 
 import { describe, expect, it, vi } from 'vitest'
 import { Context } from 'cordis'
-import AgentRegistry, { InboxItemId } from '@deepseek-ai/dsh-agent'
-import type { Agent, InboxItem, InboxPlacement } from '@deepseek-ai/dsh-agent'
+import AgentRegistry, { Inbox } from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
 import SessionStore from '@deepseek-ai/dsh-session'
 import type { SessionId, UserMessage } from '@deepseek-ai/dsh-session'
 import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
@@ -63,7 +63,14 @@ async function harness(options: { commands?: boolean; skills?: boolean } = {}):
 /** Register a live structural agent stub (api-proxy-view precedent: only id/session/status/ctx are read). */
 function stubAgent(ctx: Context, sessionId?: SessionId): Agent {
   const session = ctx.sessions.create(sessionId)
-  const agent = { id: session.id, session, status: 'idle', ctx } as Agent
+  const inbox = new Inbox(session)
+  const agent = {
+    id: session.id,
+    session,
+    inbox,
+    status: 'idle',
+    ctx,
+  } as Agent
   ctx.agents.register(agent)
   return agent
 }
@@ -264,7 +271,7 @@ describe('host/commands-changed frame', () => {
   })
 })
 
-/** Build one frozen inbox message for the live `agent/inbox/*` events. */
+/** Build one frozen inbox message. */
 function inboxMessage(id: string, text: string, rpcId?: string): UserMessage {
   return freezeMessage({
     id: MessageId(id),
@@ -274,27 +281,19 @@ function inboxMessage(id: string, text: string, rpcId?: string): UserMessage {
   })
 }
 
-/** Build one addressable inbox occurrence around a frozen message. */
-function inboxItem(id: string, message: UserMessage, placement: InboxPlacement): InboxItem {
-  return { id: InboxItemId(id), message, placement }
-}
-
 describe('session.updateQueue', () => {
-  it('routes an addressable action and reports a lost claim race', async () => {
+  it('splices a queued message and reports a lost claim race', async () => {
     const ctx = await harness()
     const agent = stubAgent(ctx)
-    const seen: unknown[] = []
-    agent.updateInbox = (id, action) => {
-      seen.push({ id, action })
-      return id === InboxItemId('present') ? 'applied' : 'not-found'
-    }
+    const present = inboxMessage('present', 'before')
+    agent.inbox.splice('next-turn', 0, 0, [present])
     const api = createApiProxy(ctx, DEFAULTS)
 
     const applied = await api.sessions.updateQueue({
       rpcId: RpcId('q-apply'),
       payload: {
         sessionId: agent.id,
-        itemId: InboxItemId('present'),
+        itemId: MessageId('present'),
         action: { kind: 'edit', content: [{ type: 'text', text: 'edited' }] },
       },
     })
@@ -303,15 +302,15 @@ describe('session.updateQueue', () => {
       rpcId: RpcId('q-missing'),
       payload: {
         sessionId: agent.id,
-        itemId: InboxItemId('claimed'),
+        itemId: MessageId('claimed'),
         action: { kind: 'remove' },
       },
     })
     expect(expectErr(missing)).toMatchObject({ code: 'queue-item-not-found' })
-    expect(seen).toEqual([
-      { id: 'present', action: { kind: 'edit', content: [{ type: 'text', text: 'edited' }] } },
-      { id: 'claimed', action: { kind: 'remove' } },
-    ])
+    expect(agent.inbox.nextTurn[0]).toMatchObject({
+      id: 'present',
+      content: [{ type: 'text', text: 'edited' }],
+    })
   })
 
   it('rejects a stale occurrence without resuming a cold agent', async () => {
@@ -322,7 +321,7 @@ describe('session.updateQueue', () => {
       rpcId: RpcId('q-cold'),
       payload: {
         sessionId: 'cold-session' as SessionId,
-        itemId: InboxItemId('stale-item'),
+        itemId: MessageId('stale-item'),
         action: { kind: 'remove' },
       },
     })
@@ -333,100 +332,24 @@ describe('session.updateQueue', () => {
 })
 
 describe('session/queue frames', () => {
-  it('folds nested mutations observed before their outer enqueue', async () => {
-    const ctx = await harness()
-    const agent = stubAgent(ctx)
-    const original = inboxItem('i-edit', inboxMessage('m-edit', 'before'), 'queued')
-    const edited = inboxItem('i-edit', inboxMessage('m-edit', 'after'), 'queued')
-    const removed = inboxItem('i-remove', inboxMessage('m-remove', 'remove me'), 'queued')
-    ctx.on('agent/inbox/enqueue', (subject, item) => {
-      if (subject !== agent) return
-      if (item.id === original.id) ctx.emit('agent/inbox/update', agent, edited)
-      if (item.id === removed.id) ctx.emit('agent/inbox/discard', agent, [removed])
-    })
-    const api = createApiProxy(ctx, DEFAULTS)
-    const live = new AbortController()
-    const collected = collect<MuxFrame>(
-      api.events.mux({ rpcId: RpcId('t-mux-reentrant'), payload: {} }, live.signal), 2, live)
-
-    ctx.emit('agent/inbox/enqueue', agent, original)
-    ctx.emit('agent/inbox/enqueue', agent, removed)
-
-    const liveFrames = (await collected).filter(frame => frame.type === 'session/queue')
-    expect(liveFrames.map(frame => frame.items)).toEqual([
-      [{ id: edited.id, message: edited.message }],
-    ])
-    const replay = new AbortController()
-    const replayFrames = await collect<MuxFrame>(
-      api.events.mux({ rpcId: RpcId('t-mux-reentrant-replay'), payload: {} }, replay.signal), 2, replay)
-    expect(replayFrames.filter(frame => frame.type === 'session/queue')).toEqual(liveFrames)
-  })
-
-  it('publishes complete live snapshots and replays the latest snapshot on reconnect', async () => {
+  it('publishes the durable next-turn baseline without duplicating message identity', async () => {
     const ctx = await harness()
     const api = createApiProxy(ctx, DEFAULTS)
     const agent = stubAgent(ctx)
-    const live = new AbortController()
-    const liveStream = api.events.mux({ rpcId: RpcId('t-mux-live'), payload: {} }, live.signal)
-    // subscribed baseline + one queued snapshot; pending steering stays off this wire.
-    const liveCollected = collect<MuxFrame>(liveStream, 2, live)
-
-    const queued = inboxItem('i-1', inboxMessage('m-1', 'queued prompt'), 'queued')
-    const steering = inboxItem('i-2', inboxMessage('m-2', 'steering prompt'), 'steering')
-    ctx.emit('agent/inbox/enqueue', agent, queued)
-    ctx.emit('agent/inbox/enqueue', agent, steering)
-
-    const liveFrames = (await liveCollected).filter(f => f.type === 'session/queue')
-    expect(liveFrames).toEqual([
-      {
-        type: 'session/queue',
-        sessionId: agent.id,
-        items: [{ id: queued.id, message: queued.message }],
-      },
-    ])
-
-    // A fresh mux connection replays only the current authoritative snapshot.
-    const replay = new AbortController()
-    const replayFrames = await collect<MuxFrame>(
-      api.events.mux({ rpcId: RpcId('t-mux-replay'), payload: {} }, replay.signal), 2, replay)
-    expect(replayFrames.filter(f => f.type === 'session/queue')).toEqual([liveFrames[0]])
-  })
-
-  it('publishes edits in place in the authoritative order', async () => {
-    const ctx = await harness()
-    const api = createApiProxy(ctx, DEFAULTS)
-    const agent = stubAgent(ctx)
-    const abort = new AbortController()
-    const collected = collect<MuxFrame>(
-      api.events.mux({ rpcId: RpcId('t-mux-updates'), payload: {} }, abort.signal), 5, abort)
-    const first = inboxItem('i-a', inboxMessage('m-a', 'a'), 'queued')
-    const second = inboxItem('i-b', inboxMessage('m-b', 'b'), 'queued')
-    const edited = inboxItem('i-b', inboxMessage('m-b', 'b edited'), 'queued')
-    ctx.emit('agent/inbox/enqueue', agent, first)
-    ctx.emit('agent/inbox/enqueue', agent, second)
-    ctx.emit('agent/inbox/update', agent, edited)
-    ctx.emit('agent/inbox/dequeue', agent, edited)
-
-    const frames = (await collected).filter(frame => frame.type === 'session/queue')
-    expect(frames.map(frame => frame.items)).toEqual([
-      [{ id: first.id, message: first.message }],
-      [{ id: first.id, message: first.message }, { id: second.id, message: second.message }],
-      [{ id: first.id, message: first.message }, { id: edited.id, message: edited.message }],
-      [{ id: first.id, message: first.message }],
-    ])
-  })
-
-  it('publishes an empty snapshot after terminal discard', async () => {
-    const ctx = await harness()
-    const api = createApiProxy(ctx, DEFAULTS)
-    const agent = stubAgent(ctx)
-    const doomed = inboxItem('i-doomed', inboxMessage('m-5', 'doomed'), 'queued')
-    ctx.emit('agent/inbox/enqueue', agent, doomed)
-    ctx.emit('agent/inbox/discard', agent, [doomed])
+    const queued = inboxMessage('m-1', 'queued prompt')
+    const steering = inboxMessage('m-2', 'steering prompt')
+    agent.inbox.splice('next-turn', 0, 0, [queued])
+    agent.inbox.splice('next-step', 0, 0, [steering])
 
     const abort = new AbortController()
     const frames = await collect<MuxFrame>(
-      api.events.mux({ rpcId: RpcId('t-mux-swept'), payload: {} }, abort.signal), 1, abort)
-    expect(frames.filter(frame => frame.type === 'session/queue')).toHaveLength(0)
+      api.events.mux({ rpcId: RpcId('t-mux-baseline'), payload: {} }, abort.signal), 2, abort)
+    expect(frames.filter(frame => frame.type === 'session/queue')).toEqual([
+      {
+        type: 'session/queue',
+        sessionId: agent.id,
+        items: [queued],
+      },
+    ])
   })
 })
diff --git a/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts b/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
index 103ea25bc1..52e40decdc 100644
--- a/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
+++ b/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
@@ -45,10 +45,7 @@ function stubAgent(session: Session): Agent {
     options: {},
     session,
     status: 'idle',
-    acceptsNextStep: false,
     ctx: new Context(),
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject: () => {},
diff --git a/packages/host/apiproxy/tests/rpc-schemas.spec.ts b/packages/host/apiproxy/tests/rpc-schemas.spec.ts
index 80cd0baf4c..9d97501e74 100644
--- a/packages/host/apiproxy/tests/rpc-schemas.spec.ts
+++ b/packages/host/apiproxy/tests/rpc-schemas.spec.ts
@@ -380,7 +380,7 @@ describe('events frame schemas', () => {
       { type: 'question/requested', sessionId: 's', questions: [{ id: 'q', question: 'Q?', options: [{ label: 'L' }], multiSelect: true }] },
       { type: 'question/resolved', sessionId: 's', questionRpcId: 'r', outcome: 'answered' },
       { type: 'session/queue', sessionId: 's', items: [
-        { id: 'i1', message: { id: 'm1', role: 'user', content: [{ type: 'text', text: 'queued prompt' }], source: { kind: 'user', rpcId: 'r9' } } },
+        { id: 'm1', role: 'user', content: [{ type: 'text', text: 'queued prompt' }], source: { kind: 'user', rpcId: 'r9' } },
       ] },
       { type: 'session/projection', sessionId: 's', key: 'todos', value: [{ content: 'x', status: 'pending' }], seq: 7 },
       { type: 'stream/error', error: { code: 'internal', message: 'm', details: {} } },
@@ -401,8 +401,8 @@ describe('events frame schemas', () => {
 
   it('rejects a queue snapshot with malformed items', () => {
     expect(() => muxFrameSchema.parse({ type: 'session/queue', sessionId: 's', items: 'x' })).toThrow()
-    expect(() => muxFrameSchema.parse({ type: 'session/queue', sessionId: 's', items: [{ id: '', message: {} }] })).toThrow()
-    expect(() => muxFrameSchema.parse({ type: 'session/queue', sessionId: 's', items: [{ id: 'i', message: { id: 'm', role: 'user', content: [], source: {} } }] })).toThrow()
+    expect(() => muxFrameSchema.parse({ type: 'session/queue', sessionId: 's', items: [{ id: '', role: 'user', content: [], source: { kind: 'user' } }] })).toThrow()
+    expect(() => muxFrameSchema.parse({ type: 'session/queue', sessionId: 's', items: [{ id: 'm', role: 'assistant', content: [], source: { kind: 'user' } }] })).toThrow()
   })
 
   it('accepts every host frame branch', () => {
diff --git a/packages/pty/pty-local/tests/index.spec.ts b/packages/pty/pty-local/tests/index.spec.ts
index 7b87fe6b10..3976e586cb 100644
--- a/packages/pty/pty-local/tests/index.spec.ts
+++ b/packages/pty/pty-local/tests/index.spec.ts
@@ -41,8 +41,8 @@ function config(): ResolvedConfig {
 function agent(ctx: Context): Agent {
   const id = SessionId('agent')
   return {
-    id, options: {}, session: new Session(id), status: 'idle', acceptsNextStep: false, ctx,
-    followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+    id, options: {}, session: new Session(id), status: 'idle', ctx,
+    followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
   }
 }
 
@@ -248,8 +248,8 @@ describe('pty-local plugin shape', () => {
     const session = ctx.sessions.create(SessionId('mode-owner'))
     const ownerFiber = await ctx.plugin(() => {})
     const owner: Agent = {
-      id: session.id, options: {}, session, status: 'idle', acceptsNextStep: false, ctx: ownerFiber.ctx,
-      followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+      id: session.id, options: {}, session, status: 'idle', ctx: ownerFiber.ctx,
+      followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
     }
     ctx.agents.register(owner)
     const providerFiber = await registerStubLocalBackend(ctx, () => stubLocalSession())
@@ -291,8 +291,8 @@ describe('pty-local plugin shape', () => {
     const session = ctx.sessions.create(SessionId('pending-mode-owner'))
     const ownerFiber = await ctx.plugin(() => {})
     const owner: Agent = {
-      id: session.id, options: {}, session, status: 'idle', acceptsNextStep: false, ctx: ownerFiber.ctx,
-      followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+      id: session.id, options: {}, session, status: 'idle', ctx: ownerFiber.ctx,
+      followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
     }
     ctx.agents.register(owner)
     const gate = Promise.withResolvers<undefined>()
diff --git a/packages/pty/pty-local/tests/local.spec.ts b/packages/pty/pty-local/tests/local.spec.ts
index c3fb33c75c..c2cb23cb59 100644
--- a/packages/pty/pty-local/tests/local.spec.ts
+++ b/packages/pty/pty-local/tests/local.spec.ts
@@ -34,8 +34,8 @@ function stubAgent(ctx: Context, rawId: string): Agent {
   const id = SessionId(rawId)
   const scope = ctx.plugin(() => {})
   return {
-    id, options: {}, session: new Session(id), status: 'idle', acceptsNextStep: false, ctx: scope.ctx,
-    followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+    id, options: {}, session: new Session(id), status: 'idle', ctx: scope.ctx,
+    followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
   }
 }
 
diff --git a/packages/pty/pty/tests/service.spec.ts b/packages/pty/pty/tests/service.spec.ts
index ba0996841c..cf5c4f0bab 100644
--- a/packages/pty/pty/tests/service.spec.ts
+++ b/packages/pty/pty/tests/service.spec.ts
@@ -26,10 +26,7 @@ function stubAgent(ctx: Context, rawId: string): Agent {
     options: {},
     session: new Session(id),
     status: 'idle',
-    acceptsNextStep: false,
     ctx: scopeFiber.ctx,
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject: () => {},
diff --git a/packages/pty/tool-pty/tests/loader-composition.spec.ts b/packages/pty/tool-pty/tests/loader-composition.spec.ts
index f6ad1084c6..da8555e4c8 100644
--- a/packages/pty/tool-pty/tests/loader-composition.spec.ts
+++ b/packages/pty/tool-pty/tests/loader-composition.spec.ts
@@ -39,8 +39,8 @@ function agent(ctx: Context): Agent {
   const scope = ctx.plugin(() => {})
   const id = SessionId('pty-loader-agent')
   const value: Agent = {
-    id, options: {}, session: new Session(id), status: 'idle', acceptsNextStep: false, ctx: scope.ctx,
-    followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+    id, options: {}, session: new Session(id), status: 'idle', ctx: scope.ctx,
+    followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
   }
   ctx.agents.register(value)
   return value
diff --git a/packages/pty/tool-pty/tests/tools.spec.ts b/packages/pty/tool-pty/tests/tools.spec.ts
index a09fcac714..ed9a41d370 100644
--- a/packages/pty/tool-pty/tests/tools.spec.ts
+++ b/packages/pty/tool-pty/tests/tools.spec.ts
@@ -17,8 +17,8 @@ function fakeAgent(ctx: Context, rawId: string): Agent {
   const scope = ctx.plugin(() => {})
   const id = SessionId(rawId)
   const agent: Agent = {
-    id, options: {}, session: new Session(id), status: 'idle', acceptsNextStep: false, ctx: scope.ctx,
-    followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+    id, options: {}, session: new Session(id), status: 'idle', ctx: scope.ctx,
+    followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
   }
   ctx.agents.register(agent)
   return agent
diff --git a/packages/skill/tool-skill/tests/tool-skill.spec.ts b/packages/skill/tool-skill/tests/tool-skill.spec.ts
index e866805a2d..98ae51e38a 100644
--- a/packages/skill/tool-skill/tests/tool-skill.spec.ts
+++ b/packages/skill/tool-skill/tests/tool-skill.spec.ts
@@ -45,9 +45,6 @@ function agentForCwd(cwd: string): Agent {
     options: {},
     session,
     status: 'idle',
-    acceptsNextStep: false,
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject(input) {
@@ -64,10 +61,7 @@ function sessionAgent(session: Session, id = 'tool-skill-agent'): Agent {
     options: {},
     session,
     status: 'running',
-    acceptsNextStep: false,
     ctx: new Context(),
-    send: () => {},
-    updateInbox: () => 'not-found',
     followup: () => {},
     steer: () => {},
     inject(input) {
diff --git a/packages/subagent/subagent-spawn/tests/subagent-spawn.spec.ts b/packages/subagent/subagent-spawn/tests/subagent-spawn.spec.ts
index 2d6338701d..f13c68cfa1 100644
--- a/packages/subagent/subagent-spawn/tests/subagent-spawn.spec.ts
+++ b/packages/subagent/subagent-spawn/tests/subagent-spawn.spec.ts
@@ -200,10 +200,14 @@ describe('dsh-subagent-spawn', () => {
     expect(published).toEqual([])
   })
 
-  it('a cancel from agent/inbox/enqueue maps a no-turn child log to aborted', async () => {
+  it('a cancel after the child prompt is queued maps a no-turn child log to aborted', async () => {
     const { ctx, parent } = await setup([])
     const controller = new AbortController()
-    ctx.on('agent/inbox/enqueue', () => { controller.abort('queued-window') })
+    ctx.on('session/event', (_session, event) => {
+      if (event.type === 'agent/inbox/spliced' && event.data.inserted.length > 0) {
+        queueMicrotask(() => { controller.abort('queued-window') })
+      }
+    })
     const run = await start(ctx, 'spawn', { prompt: [{ type: 'text', text: 'p' }], parent, signal: controller.signal })
     const result = await run.result
     expect(result).toMatchObject({ stopReason: 'aborted', output: [] })
diff --git a/packages/tasks/tasks-local/tests/tasks.spec.ts b/packages/tasks/tasks-local/tests/tasks.spec.ts
index 555eb6146a..5cf11732cf 100644
--- a/packages/tasks/tasks-local/tests/tasks.spec.ts
+++ b/packages/tasks/tasks-local/tests/tasks.spec.ts
@@ -23,10 +23,7 @@ function stubAgent(ctx: Context, rawId: string): Agent {
     options: {},
     session: new Session(id),
     status: 'idle' as const,
-    acceptsNextStep: false,
     ctx: scopeFiber.ctx,
-    send: () => {},
-    updateInbox: (): 'not-found' => 'not-found',
     followup: () => {},
     steer: () => {},
     inject: () => {},
diff --git a/packages/ui/tui/src/index.ts b/packages/ui/tui/src/index.ts
index 8c5322f8e6..de8288d71d 100644
--- a/packages/ui/tui/src/index.ts
+++ b/packages/ui/tui/src/index.ts
@@ -1198,7 +1198,7 @@ export function createTuiChat(
       appendNotice(`Agent "${agent.id}" is disposed.`, 'error')
       return
     }
-    if (agent.acceptsNextStep) {
+    if (agent.status === 'running') {
       // Steering is never subject to prompt admission; an attached snapshot
       // drains beside it at the same step boundary through the outbox.
       if (attachedContext !== undefined) {
diff --git a/packages/ui/tui/tests/harness.ts b/packages/ui/tui/tests/harness.ts
index 6be1183d78..a6a22ec2d9 100644
--- a/packages/ui/tui/tests/harness.ts
+++ b/packages/ui/tui/tests/harness.ts
@@ -36,8 +36,6 @@ interface FakeAgent extends Agent {
 
 export interface TuiHarnessOptions {
   status?: AgentStatus
-  /** Override the fake agent's next-step capability independently of status. */
-  acceptsNextStep?: boolean
   config?: Config
   /** Leave the session event log empty instead of seeding one turn and step. */
   omitInitialLifecycle?: boolean
@@ -193,9 +191,6 @@ export async function createTuiTestHarness<TerminalType extends Terminal, Exit e
     options: options.agentOptions ?? { provider: 'deepseek', model: 'deepseek-v4-flash' },
     session,
     status: options.status ?? 'idle',
-    get acceptsNextStep() {
-      return options.acceptsNextStep ?? this.status === 'running'
-    },
     ctx,
     sent,
     sentMessages,
@@ -205,13 +200,6 @@ export async function createTuiTestHarness<TerminalType extends Terminal, Exit e
     injected,
     injectedOptions,
     cancelled,
-    send(input, options) {
-      sent.push(input.content)
-      sentMessages.push(input)
-      sentOptions.push(options)
-      return input.id
-    },
-    updateInbox: () => 'not-found',
     followup(input) {
       sent.push(input.content)
       sentMessages.push(input)
diff --git a/packages/ui/tui/tests/tui.spec.ts b/packages/ui/tui/tests/tui.spec.ts
index e18c96c4db..0979714468 100644
--- a/packages/ui/tui/tests/tui.spec.ts
+++ b/packages/ui/tui/tests/tui.spec.ts
@@ -2636,45 +2636,6 @@ describe('pi-tui chat lifecycle and transcript', () => {
     await dispose(result)
   })
 
-  it('keeps a referenced prompt on admission when running no longer accepts next-step input', async () => {
-    const result = await setup({
-      status: 'running',
-      acceptsNextStep: false,
-      omitInitialLifecycle: true,
-      async configureContext(ctx) {
-        ctx.provide('tools', { get: () => undefined } as never)
-        await ctx.plugin(TestSessionQueryService)
-        await ctx.plugin(SessionReferenceService)
-        const source = ctx.sessions.create(SessionId('admission-src'), {
-          meta: { cwd: process.cwd(), createdAt: 1 },
-        })
-        appendUser(source, 'source background')
-        source.append('session/title', {
-          title: 'Admission source',
-          messageSeqs: [0],
-          source: { kind: 'fallback' },
-        })
-      },
-    })
-
-    result.terminal.send(formatSessionReferenceMention({
-      sessionId: SessionId('admission-src'),
-      label: 'Admission source',
-    }))
-    result.terminal.send('\r')
-    await vi.waitFor(() => { expect(result.agent.sent).toHaveLength(1) })
-
-    expect(result.agent.steered).toHaveLength(0)
-    expect(result.agent.injected).toHaveLength(0)
-    const decision = await agentEvents(result.ctx, result.agent).waterfall(
-      'agent/prompt-submit', result.agent.sentMessages[0]!,
-      new AbortController().signal, () => Promise.resolve({ kind: 'allow' as const }),
-    )
-    expect(decision.kind === 'allow' && decision.additionalContexts?.[0]?.source)
-      .toMatchObject({ kind: 'session-reference', references: [{ sessionId: 'admission-src' }] })
-    await dispose(result)
-  })
-
   it('releases the reference-admission wrapper on the ordinary allowed path', async () => {
     const result = await setup({
       async configureContext(ctx) {
@@ -4974,8 +4935,8 @@ describe('terminal mounting', () => {
     ctx.provide('tools', { get: () => undefined } as never)
     const session = ctx.sessions.create(SessionId('main'))
     ctx.agents.register({
-      id: session.id, options: {}, session, status: 'idle', acceptsNextStep: false, ctx,
-      followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+      id: session.id, options: {}, session, status: 'idle', ctx,
+      followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
     })
     const terminal = new FakeTerminal()
     mountTui(ctx, { theme: { color: false } }, { terminal, exit: vi.fn() })
@@ -4999,8 +4960,8 @@ describe('terminal mounting', () => {
     ctx.provide('tools', { get: () => undefined } as never)
     const session = ctx.sessions.create(SessionId('main'))
     ctx.agents.register({
-      id: session.id, options: {}, session, status: 'idle', acceptsNextStep: false, ctx,
-      followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+      id: session.id, options: {}, session, status: 'idle', ctx,
+      followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
     })
     const terminal = new FakeTerminal()
     // Mirror dsh-tui's own inject (minus loader, the absence under test).
@@ -5034,15 +4995,15 @@ describe('terminal mounting', () => {
 
     const otherSession = ctx.sessions.create(SessionId('other-session'))
     ctx.agents.register({
-      id: otherSession.id, options: {}, session: otherSession, status: 'idle', acceptsNextStep: false, ctx,
-      followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+      id: otherSession.id, options: {}, session: otherSession, status: 'idle', ctx,
+      followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
     })
     expect(terminal.started).toBe(0)
 
     const session = ctx.sessions.create(SessionId('late-session'))
     const agent = {
-      id: session.id, options: {}, session, status: 'idle', acceptsNextStep: false, ctx,
-      followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+      id: session.id, options: {}, session, status: 'idle', ctx,
+      followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
     } as Agent
     ctx.agents.register(agent)
     await tick()
@@ -5072,8 +5033,8 @@ describe('terminal mounting', () => {
 
     const session = ctx.sessions.create(SessionId('main-session'))
     ctx.agents.register({
-      id: session.id, options: {}, session, status: 'idle', acceptsNextStep: false, ctx,
-      followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+      id: session.id, options: {}, session, status: 'idle', ctx,
+      followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
     })
     await tick()
     expect(terminal.started).toBe(0)
@@ -5116,8 +5077,8 @@ describe('terminal mounting', () => {
     session.append('turn/start', { turn: 1 })
     session.append('step/start', { turn: 1, step: 1 })
     ctx.agents.register({
-      id: session.id, options: {}, session, status: 'running', acceptsNextStep: true, ctx,
-      followup: () => {}, steer: () => {}, inject: () => {}, send: () => {}, updateInbox: () => 'not-found', cancel() {}, whenIdle: () => Promise.resolve(),
+      id: session.id, options: {}, session, status: 'running', ctx,
+      followup: () => {}, steer: () => {}, inject: () => {}, cancel() {}, whenIdle: () => Promise.resolve(),
     })
     const terminal = new FakeTerminal()
     terminal.start = () => { throw new Error('terminal startup failed') }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 61930c815d..58228736c6 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2048,9 +2048,6 @@ importers:
 
   packages/core/agent:
     devDependencies:
-      '@deepseek-ai/dsh-brand':
-        specifier: workspace:^
-        version: link:../../util/brand
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^
         version: link:../../support/invariants