docs: document session preparation flow

docs/architecture.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/architecture.md
-architecture.md: 729a654c1379b9afab213b9bf604d5db17d01768
-architecture.zh.md: 8dc128651f01b0a64fd8c8f2148aa4644dc50399
+architecture.md: 9b84c1482cb379fd796e21db45f128ba49750c54
+architecture.zh.md: 84708fcae24623e50b0157782cf459c35a55844b

docs/architecture.md

@@ -66,15 +66,15 @@ Waterfalls are around-middleware: listeners delegate with `next()`; returning wi
 
 ## Default Loop Lifecycle
 
-A **session** is append-only. A **turn** claims one queued follow-up, waits for its predecessor's checkpoint, and may share its `running` interval ([decision](../.agents/notes/implemented/simplification/2026-07-17-one-send-one-turn.md)); injection claims none. A **step** is one model request plus tools. Quotes in the [sequence](agent-lifecycle.md) mark durable events.
+A **session** is append-only. A **turn** claims one queued follow-up, waits for its predecessor's checkpoint, and may share its `running` interval ([decision](../.agents/notes/implemented/simplification/2026-07-17-one-send-one-turn.md)); injection claims none. A **step** is one model request plus tools. Fresh creation and persisted resume first acquire an exact unpublished `SessionPreparation`; Agent and session publication happen only after private setup against that Session is ready ([decision](../.agents/notes/implemented/architecture/2026-08-05-session-preparation.md)). Quotes in the [sequence](agent-lifecycle.md) mark durable events.
 
 Creation without an id mints `<config-id>-session-<uuid>`; `sessionId` resumes or creates, while `resumeSessionId` requires history. Resume restores lineage and delegation depth before publication; setup failure emits `agent-loop/config-start-failed`.
 
 ### Turn Flow
 
 ```text
-choose declarative identity and fresh/resume path
-  -> prepare private session + agent.ctx -> await unpublished setup
+choose declarative identity and acquire fresh/restored SessionPreparation
+  -> prepare private agent.ctx around exact Session -> await unpublished setup -> invoke optional synchronous setup commit
   -> enter session + agent -> session/created -> agent/created
   -> enable driving -> agent/session-start(source) -> start driver
 forever:

docs/architecture.zh.md

@@ -66,15 +66,15 @@ waterfall（瀑布式事件）是环绕中间件：监听器通过 `next()` 委
 
 ## 默认循环生命周期
 
-**会话**采用仅追加方式。一个**轮次**领取一条已排队的后续消息，等待前一轮次的检查点，并可与其共用 `running` 区间（[决策](../.agents/notes/implemented/simplification/2026-07-17-one-send-one-turn.md)）；注入不领取输入。一个**步骤**包含一次模型请求及其工具。[时序](agent-lifecycle.md)中的引号标记持久事件。
+**会话**采用仅追加方式。一个**轮次**领取一条已排队的后续消息，等待前一轮次的检查点，并可与其共用 `running` 区间（[决策](../.agents/notes/implemented/simplification/2026-07-17-one-send-one-turn.md)）；注入不领取输入。一个**步骤**包含一次模型请求及其工具。新建与持久化恢复会先取得精确的未发布 `SessionPreparation`；只有基于该 Session 的私有设置准备完毕后，系统才会发布 agent 与会话（[决策](../.agents/notes/implemented/architecture/2026-08-05-session-preparation.md)）。[时序](agent-lifecycle.md)中的引号标记持久事件。
 
 创建时若未提供 id，流程会生成 `<config-id>-session-<uuid>`；`sessionId` 用于恢复或创建会话，而 `resumeSessionId` 要求已有历史。恢复流程在发布前还原沿袭关系和委托深度；初始化失败会发出 `agent-loop/config-start-failed`。
 
 ### 轮次流程
 
 ```text
-choose declarative identity and fresh/resume path
-  -> prepare private session + agent.ctx -> await unpublished setup
+choose declarative identity and acquire fresh/restored SessionPreparation
+  -> prepare private agent.ctx around exact Session -> await unpublished setup -> invoke optional synchronous setup commit
   -> enter session + agent -> session/created -> agent/created
   -> enable driving -> agent/session-start(source) -> start driver
 forever:

docs/config-catalog.md

@@ -108,7 +108,7 @@ export interface Config {
 
 Depends on: [`AgentOptions`](core-data-structures/core.md) · [`SessionId`](core-data-structures/core.md)
 
-Source: [`packages/core/agent-loop/src/index.ts:212`](../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:235`](../packages/core/agent-loop/src/index.ts)
 
 ## `@deepseek-ai/dsh-agent-spine-demo`
 
@@ -1135,6 +1135,8 @@ export interface Config {
   packChunks?: boolean
   /** Physical encoding; defaults to checksummed Zstandard frames. */
   compression?: JsonlCompression
+  /** Maximum cold Session preparations retained for history-to-resume reuse. */
+  preparedSessionCacheSize?: number
 }
 
 /** Physical encoding selected for JSONL session artifacts. */
@@ -1167,6 +1169,8 @@ export interface Config {
    * (network mounts). See {@link JournalMode}.
    */
   journalMode?: JournalMode
+  /** Maximum cold Session preparations retained for history-to-resume reuse. */
+  preparedSessionCacheSize?: number
 }
 
 /**

docs/cordis-catalog/events.md

@@ -297,7 +297,7 @@ A declarative agent entry failed before it could publish a live agent. Consumers
 
 Types: [SessionId](../core-data-structures/core.md)
 
-Source: [`packages/core/agent-loop/src/index.ts:158`](../../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:182`](../../packages/core/agent-loop/src/index.ts)
 
 ## `approval/*`
 
@@ -535,7 +535,7 @@ Creation announcement during session publication. A synchronous throw vetoes and
 
 Types: [Scoped](../core-data-structures/scope.md) · [Session](../core-data-structures/session.md)
 
-Source: [`packages/core/session/src/index.ts:71`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:73`](../../packages/core/session/src/index.ts)
 
 ### `session/disposed` — emit
 
@@ -556,7 +556,7 @@ Emitted once when an announced session leaves the store, including publication r
 
 Types: [Scoped](../core-data-structures/scope.md) · [Session](../core-data-structures/session.md)
 
-Source: [`packages/core/session/src/index.ts:81`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:83`](../../packages/core/session/src/index.ts)
 
 ### `session/event` — emit
 
@@ -579,7 +579,7 @@ Post-commit, fire-and-forget append feed. The listener snapshot resolves before
 
 Types: [Scoped](../core-data-structures/scope.md) · [Session](../core-data-structures/session.md) · [SessionEvent](../core-data-structures/core.md)
 
-Source: [`packages/core/session/src/index.ts:93`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:95`](../../packages/core/session/src/index.ts)
 
 ### `session/flush` — parallel
 
@@ -599,7 +599,7 @@ Awaited parallel durability checkpoint: every listener runs and the caller await
 
 Types: [Scoped](../core-data-structures/scope.md) · [Session](../core-data-structures/session.md)
 
-Source: [`packages/core/session/src/index.ts:102`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:104`](../../packages/core/session/src/index.ts)
 
 ## `settings/*`
 

docs/cordis-catalog/services.md

@@ -44,7 +44,7 @@ async resume(ownerCtx: Context, options: ResumeAgentOptions): Promise<AgentHandl
 
 Types: [Agent](../core-data-structures/core.md) · [AgentOptions](../core-data-structures/core.md) · [SessionHeader](../core-data-structures/persistence.md) · [SessionId](../core-data-structures/core.md)
 
-Source: [`packages/core/agent-loop/src/index.ts:253`](../../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:277`](../../packages/core/agent-loop/src/index.ts)
 
 ## `ctx.agents` — `AgentRegistry`
 
@@ -1175,46 +1175,51 @@ abstract create(meta: SessionHeader): Promise<void>
 abstract append(id: SessionId, events: readonly SessionEvent[]): Promise<void>
 
 /**
- * Load a header and balanced contiguous log. A complete interrupted final
- * turn is preserved and durably closed with missing tool errors plus any open
- * step and turn boundaries; only a torn final record is discarded. Unknown
- * versions and corruption in the committed prefix reject. Implementations
- * MUST NOT crash-repair an identity still bound to a live Session: a balanced
- * live log may return with its stored header as a durable snapshot, while an
- * open live turn rejects.
- * A coordinator-backed cold load reserves the identity across storage awaits,
- * so concurrent publication of a same-id live Session rejects.
- * Returned events are detached, and every identified message is deeply
- * frozen. Coordinator-backed implementations upgrade supported pre-identity
- * message events before validation; other malformed messages reject before
- * any stored event is returned.
+ * Prepare the exact unpublished Session used by resume. Implementations may
+ * reuse object graphs retained by an earlier {@link inspect}; disposal
+ * releases an unpublished reservation.
+ * @param id - persisted session to prepare.
+ * @param signal - optional cancellation for preparation work.
+ * @returns one owned unpublished Session preparation.
+ */
+async prepare(id: SessionId, signal?: AbortSignal): Promise<SessionPreparation>
+
+/**
+ * Load an immutable balanced logical view and commit any required cold
+ * recovery. A complete interrupted final turn is preserved and durably
+ * closed with missing tool errors plus any open step and turn boundaries;
+ * only a torn final record is discarded. Unknown versions and corruption in
+ * the committed prefix reject. Implementations MUST NOT crash-repair an
+ * identity still bound to a live Session: a balanced live log may return as a
+ * durable snapshot, while an open live turn rejects. Returned values may be
+ * shared with immutable live or prepared state and must not be mutated.
  * @param id - the persisted session to reload.
  * @returns the header and a log ending on a balanced `turn/end`.
  */
-abstract load(id: SessionId): Promise<{ meta: SessionHeader; events: SessionEvent[] }>
+abstract load(id: SessionId): Promise<SessionInspection>
 
 /**
- * Inspect a header and its valid contiguous stored prefix without repairing
- * a torn tail, closing an interrupted turn, or publishing coordinator state.
- * This read is serialized with writes for the same id and returns detached
- * values with upgraded, deeply frozen identified messages, so observers
- * cannot mutate message identity/content or backend-owned state. Other
- * malformed messages reject.
+ * Inspect an immutable balanced logical session without committing recovery
+ * or publishing it. A complete interrupted turn receives synthetic closers
+ * in memory and a torn physical tail remains untouched. Coordinator-backed
+ * implementations retain the exact unpublished Session for bounded reuse by
+ * a later {@link prepare}; callers borrow only its immutable header and log.
  * @param id - the persisted session to inspect.
  * @param signal - optional cancellation for queued and backend read work.
- * @returns the header and valid stored event prefix exactly as observed.
+ * @returns the validated header and balanced logical event log.
  */
-abstract inspect(id: SessionId, signal?: AbortSignal): Promise<{ meta: SessionHeader; events: SessionEvent[] }>
+abstract inspect(id: SessionId, signal?: AbortSignal): Promise<SessionInspection>
 
 /**
  * Read the stored events from `fromSeq` onward — the read-from-seq
  * primitive for read models that resume from a watermark (e.g. a persisted
- * projection cache folding only the tail past its checkpoint). Like
- * {@link inspect} it is non-mutating and detached: no torn-tail truncation,
- * no synthetic closers, no coordinator-state publication; only events from
- * the valid contiguous stored prefix are returned, so a torn fragment never
- * reaches the caller. `fromSeq` at or beyond the stored prefix returns an
- * empty event list (never an error). Backends whose medium can seek by seq
+ * projection cache folding only the tail past its checkpoint). Unlike
+ * {@link inspect}, it is a detached physical suffix read: no preparation
+ * cache, torn-tail truncation, synthetic closers, or coordinator-state
+ * publication. Only events from the valid contiguous stored prefix are
+ * returned, so a torn fragment never reaches the caller. `fromSeq` at or
+ * beyond the stored prefix returns an empty event list (never an error).
+ * Backends whose medium can seek by seq
  * (SQLite) read only the suffix; sequential media (JSONL, both encodings)
  * still parse the whole artifact and skip forward — the primitive bounds
  * what is RETURNED and refolded, not every backend's physical read.
@@ -1245,9 +1250,9 @@ abstract list(signal?: AbortSignal): Promise<SessionHeader[]>
 abstract listSnapshots(signal?: AbortSignal): Promise<SessionPersistenceSnapshot[]>
 ```
 
-Types: [SessionEvent](../core-data-structures/core.md) · [SessionHeader](../core-data-structures/persistence.md) · [SessionId](../core-data-structures/core.md) · [SessionLocation](../core-data-structures/persistence.md) · [SessionPersistenceSnapshot](../core-data-structures/persistence.md)
+Types: [SessionEvent](../core-data-structures/core.md) · [SessionHeader](../core-data-structures/persistence.md) · [SessionId](../core-data-structures/core.md) · [SessionInspection](../core-data-structures/persistence.md) · [SessionLocation](../core-data-structures/persistence.md) · [SessionPersistenceSnapshot](../core-data-structures/persistence.md) · [SessionPreparation](../core-data-structures/persistence.md)
 
-Source: [`packages/session-persistence/session-persistence/src/index.ts:52`](../../packages/session-persistence/session-persistence/src/index.ts)
+Source: [`packages/session-persistence/session-persistence/src/index.ts:66`](../../packages/session-persistence/session-persistence/src/index.ts)
 
 ## `ctx.sessionProjectionCache` — `SessionProjectionCache`
 
@@ -1608,7 +1613,7 @@ create(id?: SessionId, options?: CreateSessionOptions): Session
  *   lossless-JSON record with valid scalar fields, or `meta.cwd` is a
  *   non-absolute path.
  */
-prepare(id?: SessionId, options?: CreateSessionOptions): Session
+prepare(id?: SessionId, options?: PrepareSessionOptions): Session
 
 /**
  * Enter a {@link prepare}d session into the store: install the module-private
@@ -1688,9 +1693,9 @@ list(): Session[]
 fork(source: SessionForkSource, boundary?: number, childSessionId?: SessionId): Session
 ```
 
-Types: [CreateSessionOptions](../core-data-structures/persistence.md) · [Session](../core-data-structures/session.md) · [SessionId](../core-data-structures/core.md)
+Types: [CreateSessionOptions](../core-data-structures/persistence.md) · [PrepareSessionOptions](../core-data-structures/persistence.md) · [Session](../core-data-structures/session.md) · [SessionId](../core-data-structures/core.md)
 
-Source: [`packages/core/session/src/index.ts:767`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:801`](../../packages/core/session/src/index.ts)
 
 ## `ctx.sessionTitle` — `SessionTitleService`
 

docs/core-data-structures/persistence.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/core-data-structures/persistence.md
-persistence.md: ed19af4e739c153ce1beec7c1e8de06f0c0bca53
-persistence.zh.md: 83d8ba3c0eabe57b9df661fb86ec05d3db98d8b6
+persistence.md: 4b4b1ed0c0809bb277cd0118bb14f893faa4d821
+persistence.zh.md: 226dbd03c514d2c76838d7ee64ecc699a7852cba

docs/core-data-structures/persistence.md

@@ -4,7 +4,7 @@ English | [中文](persistence.zh.md)
 
 The **durability seam** for the event log. [session.md](session.md) describes the in-memory `Session` — the append-only `SessionEvent` log that is the source of truth. This page describes how that log is made durable: the abstract `SessionPersistence` service, its backends, the flush checkpoint, crash recovery, and the metadata header that travels alongside the log. The event vocabulary the log carries is enumerated, member by member, in the generated [persistence log event catalog](../persistence-catalog.md).
 
-The seam is a textbook [capability seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md): one abstract service ([dsh-session-persistence](../../packages/session-persistence/session-persistence), `ctx.sessionPersistence`) defining locate/create/append, crash-repairing load, non-mutating inspect, and lightweight list/snapshot observation over the existing `SessionEvent` — **no parallel persisted type** — and two interchangeable backends implementing the same contract. See the [session-persistence Agent Note](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md).
+The seam is a textbook [capability seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md): one abstract service ([dsh-session-persistence](../../packages/session-persistence/session-persistence), `ctx.sessionPersistence`) defining locate/create/append, reusable Session preparation, logical load/inspect, physical suffix reads, and lightweight list/snapshot observation over the existing `SessionEvent` — **no parallel persisted event type** — and two interchangeable backends implementing the same contract. See the [session-persistence Agent Note](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md).
 
 ## The flush checkpoint
 
@@ -14,9 +14,9 @@ The seam is a textbook [capability seam](../../.agents/notes/implemented/archite
 
 A backend that reloads a log crashed mid-turn finds an open `turn/start` with no `turn/end`. It does **not** truncate — a single turn can be huge in a long-horizon task (many steps, large tool output), and those events were durably appended before the crash. Instead it closes the orphaned turn with a synthetic `turn/end { reason: { kind: 'interrupted' } }`, keeping the interrupted execution balanced without changing any standalone events before or after it. `interrupted` is the one `TurnEndReason` no loop emits (see [session.md](session.md#why-a-turn-ended-turnendreasonmap)).
 
-Repair applies only to cold sessions. For a live id, `SessionPersistence.load(id)` snapshots the in-memory log, waits until that snapshot is durable, and returns it with the stored header only when balanced; an open live turn rejects rather than receiving synthetic interruption boundaries. A coordinator-backed cold load reserves the id across backend reads and repair writes, so concurrent publication of a same-id live session rejects and rolls back. HMR also adopts a live prefix without closing its active turn.
+Repair applies only to cold sessions. For a live id, `SessionPersistence.load(id)` waits until the authoritative in-memory snapshot is durable and returns it only when balanced; an open live turn rejects rather than receiving synthetic interruption boundaries. HMR adopts a live prefix without closing its active turn.
 
-`SessionPersistence.inspect(id)` is the observer counterpart to recovery: it returns a detached valid stored prefix without truncating a torn record, adding interruption closers, or publishing write state. Same-id serialization keeps it coherent with backend writes. Derived read models use `inspect`, never `load`, so observing a checkpointed open turn cannot mutate the log if live ownership begins concurrently.
+`SessionPersistence.inspect(id)` constructs an immutable balanced logical Session without publishing it or writing recovery. Torn physical tails remain untouched, and synthetic interruption closers exist only in memory. Coordinator-backed implementations retain that exact unpublished Session in a bounded LRU, so repeated history reads and a later `prepare(id)` share one read, decompression, validation, freeze, and Session construction. `prepare(id)` reserves the Session, commits pending repair, and returns a disposable publication handle; `load(id)` uses the same machinery to commit repair without publication. The [Session preparation decision](../../.agents/notes/implemented/architecture/2026-08-05-session-preparation.md) owns this lifecycle.
 
 ## `SessionLocation` — optional per-session artifact target
 
@@ -82,7 +82,7 @@ interface SessionHeader {
 
 ## `CreateSessionOptions` — seeding and metadata
 
-Creating a `Session` through the store takes a `seed` (initial replay or fork history) and `meta` (the storage-level fields the store folds into a `SessionHeader`). The store fills in `version`/`id` and defaults `createdAt`; the caller supplies the validated absolute `cwd`, the `parentSession` lineage, the `seedLength` seed boundary, the optional coarse `origin`, the `delegationDepth`, and — only when reconstructing a persisted session — the original `createdAt` to preserve it. `origin: 'subagent'` lets product navigation hide duplicate child rows; it does not prove that a descriptor is valid or that the child can resume.
+Creating a `Session` through the store takes a `seed` (initial replay or fork history) and `meta` (the storage-level fields the store folds into a `SessionHeader`). The store fills in `version`/`id` and defaults `createdAt`; the caller may supply the validated absolute `cwd`, the `parentSession` lineage, the `seedLength` seed boundary, the optional coarse `origin`, the `delegationDepth`, and an existing `createdAt`. `origin: 'subagent'` lets product navigation hide duplicate child rows; it does not prove that a descriptor is valid or that the child can resume.
 
 ```ts type-equiv
 /**
@@ -110,6 +110,72 @@ interface CreateSessionOptions {
 
 Replay/fork is therefore `ctx.sessions.create(id, { seed: seedEvents })`; resuming a *persisted* session into a live agent is `ctx.agents.resume({ resumeSessionId })`.
 
+## Preparation and restoration ownership
+
+`SessionStore.prepare()` accepts ordinary creation options or fresh persistence graphs transferred through `RestoredSessionOptions`. The restoration branch validates and freezes the transferred header and events in place, so callers must retain no mutable aliases. `SessionPreparation` then owns the exact unpublished Session until publication or rollback; disposal is synchronous and idempotent. Persistence inspection exposes only `SessionInspection`, an immutable logical view borrowed from the same prepared Session.
+
+```ts type-equiv
+/**
+ * Fresh storage values transferred to {@link SessionStore.prepare} without a
+ * second serialization copy. Callers retain no mutable aliases.
+ */
+interface RestoredSessionOptions {
+  /** Fresh detached storage events to validate and freeze in place. */
+  readonly seed: SessionEvent[]
+  /** Fresh detached storage metadata to validate and freeze in place. */
+  readonly meta: SessionHeader
+  /** Select the persistence ownership-transfer path. */
+  readonly seedSource: 'persistence'
+}
+```
+
+```ts type-equiv
+/** Inputs accepted while constructing an unpublished Session. */
+type PrepareSessionOptions =
+  | (CreateSessionOptions & { readonly seedSource?: undefined })
+  | RestoredSessionOptions
+```
+
+```ts type-equiv
+/** Options for a preparation whose provider retains unpublished state. */
+interface SessionPreparationOptions {
+  /** Release provider-owned state when the Session was not published. */
+  readonly release?: () => void
+}
+```
+
+```ts public-api
+/**
+ * One exact unpublished Session and the provider state that keeps it usable.
+ * Disposal is synchronous and idempotent. Providers decide whether release
+ * returns the Session to a cache or discards it; publication may consume that
+ * state before disposal, making the callback a no-op.
+ */
+declare class SessionPreparation implements Disposable {
+  /** The exact Session to use for setup and publication. */
+  readonly session: Session;
+  /**
+   * Wrap an unpublished Session in one preparation lifetime.
+   * @param session - exact unpublished Session.
+   * @param options - optional provider release behavior.
+   * @returns a preparation disposed after publication or rollback.
+   */
+  static create(session: Session, options?: SessionPreparationOptions): SessionPreparation;
+  /** Release provider state once when this preparation leaves its caller. */
+  [Symbol.dispose](): void;
+}
+```
+
+```ts type-equiv
+/** Immutable logical session prepared from persistence or a live owner. */
+interface SessionInspection {
+  /** Validated immutable session metadata. */
+  readonly meta: SessionHeader
+  /** Validated contiguous logical event log. */
+  readonly events: readonly SessionEvent[]
+}
+```
+
 ## Lightweight source revisions
 
 Consumers of derived state compare a cheap opaque revision before loading a full event log. The persistence backend owns its representation and changes it transactionally with append or mutating load repair; callers compare it only for equality.
@@ -134,7 +200,7 @@ interface SessionPersistenceSnapshot {
 
 ## The backends
 
-Both implement the same abstract `SessionPersistence` (locate/create/append/load/inspect/list/listSnapshots over `SessionEvent`, with optional cancellation on observation methods) and pass `runPersistenceContract`, proving the seam is genuinely backend-agnostic:
+Both implement the same abstract `SessionPersistence` (locate/create/append/prepare/load/inspect/readFrom/list/listSnapshots over `SessionEvent`, with optional cancellation on observation methods) and pass `runPersistenceContract`, proving the seam is genuinely backend-agnostic:
 
 - **[dsh-session-persistence-jsonl](../../packages/session-persistence/session-persistence-jsonl)** — an append-only logical JSONL log per session, stored as checksummed concatenated Zstandard frames by default or raw lines by configuration, with crash-safe atomic writes, interrupted-turn recovery, and a read/replay path.
 - **[dsh-session-persistence-sqlite](../../packages/session-persistence/session-persistence-sqlite)** — `node:sqlite`, one row per `SessionEvent`. The row shape `(session_id, seq, type, time, data, source_event_seqs, surface_op)` maps 1:1 onto the event, including optional surface metadata, so there is no parallel persisted schema to keep in sync.

docs/core-data-structures/persistence.zh.md

@@ -4,7 +4,7 @@
 
 事件日志的**持久性 seam**。[session.md](session.md) 描述了内存中的 `Session`：仅追加的 `SessionEvent` 日志即为真源。本页描述如何使该日志持久化：抽象的 `SessionPersistence` 服务、它的后端、flush 检查点、崩溃恢复，以及随日志一同存储的元数据头。日志承载的事件词汇在生成的[持久化日志事件目录](../persistence-catalog.md)中逐项列举。
 
-该 seam 是典型的[能力 seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md)：一个抽象服务（[dsh-session-persistence](../../packages/session-persistence/session-persistence)，`ctx.sessionPersistence`）在现有 `SessionEvent` 上定义 locate/create/append、会执行崩溃修复的 load、不会修改数据的 inspect，以及轻量的 list/snapshot 观察——**没有平行的持久化类型**——以及两个实现同一契约的可互换后端。见 [session-persistence Agent Note（agent 决策记录）](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md)。
+该 seam 是典型的[能力 seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md)：一个抽象服务（[dsh-session-persistence](../../packages/session-persistence/session-persistence)，`ctx.sessionPersistence`）在现有 `SessionEvent` 上定义 locate/create/append、可复用的 Session 准备流程、逻辑 load/inspect、物理后缀读取，以及轻量的 list/snapshot 观察——**没有平行的持久化事件类型**——以及两个实现同一契约的可互换后端。见 [session-persistence Agent Note](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md)。
 
 ## flush 检查点
 
@@ -14,9 +14,9 @@
 
 后端重新加载一个在轮次中途崩溃的日志时，会发现一个已打开的 `turn/start` 却没有 `turn/end`。它**不会**截断日志：在长周期任务中，单个轮次可能非常庞大（许多步骤、大量工具输出），而这些事件在崩溃前已被持久追加。后端改为用一个合成的 `turn/end { reason: { kind: 'interrupted' } }` 关闭这个遗留轮次，在不改变其前后任何独立事件的情况下配平被中断的执行。`interrupted` 是唯一一个不由循环发出的 `TurnEndReason`（见 [session.md](session.md#why-a-turn-ended-turnendreasonmap)）。
 
-修复仅适用于冷会话。对于活跃 id，`SessionPersistence.load(id)` 会对内存日志拍摄快照，等待该快照完成持久化，并且只在日志平衡时连同已存储的 header 返回；若活跃轮次仍未闭合，则拒绝操作，而不是添加合成的中断边界。由协调器管理的冷加载会在后端读取和修复写入期间占用该 id，因此并发发布同 id 的活跃会话会被拒绝并回滚。HMR 也会接管活跃前缀，而不会关闭其中正在进行的轮次。
+修复仅适用于冷会话。对于活跃 id，`SessionPersistence.load(id)` 会等待权威内存快照完成持久化，并且只在日志平衡时返回；若活跃轮次仍未闭合，则拒绝操作，而不是添加合成的中断边界。HMR 会接管活跃前缀，而不会关闭其中正在进行的轮次。
 
-`SessionPersistence.inspect(id)` 是恢复机制面向观察方的对等操作：它返回已存储有效前缀的独立副本，不截断不完整记录、不添加中断结束事件，也不发布写入状态。同 id 串行化确保它与后端写入保持一致。派生读取模型使用 `inspect`，绝不使用 `load`，因此即使活跃所有权并发建立，观察已落检查点但仍未闭合的轮次也不会修改日志。
+`SessionPersistence.inspect(id)` 会构造一个不可变且已配平的逻辑 Session，但不发布它，也不写入恢复内容。撕裂的物理尾部保持不变，合成的中断 closer 只存在于内存中。使用协调器的实现会在有界 LRU 中保留这个精确的未发布 Session，因此重复历史读取与后续 `prepare(id)` 可复用同一次读取、解压、验证、冻结及 Session 构造。`prepare(id)` 会预留该 Session、提交待处理修复并返回可 dispose 的发布句柄；`load(id)` 使用相同机制提交修复，但不会发布 Session。该生命周期由 [Session 准备阶段决策](../../.agents/notes/implemented/architecture/2026-08-05-session-preparation.md)定义。
 
 ## `SessionLocation`——可选的逐会话产物目标
 
@@ -82,7 +82,7 @@ interface SessionHeader {
 
 ## `CreateSessionOptions`：seed 与元数据
 
-通过 store 创建 `Session` 时会接收 `seed`（初始回放或 fork 历史）与 `meta`（store 折叠进 `SessionHeader` 的存储层字段）。store 填充 `version`/`id` 并为 `createdAt` 提供默认值；调用方提供已校验的绝对 `cwd`、`parentSession` 谱系、`seedLength` 种子边界、可选的粗粒度 `origin`、`delegationDepth`，以及——仅在重建已持久化会话时——需要保留的原始 `createdAt`。`origin: 'subagent'` 让产品导航能够隐藏重复的 child 行；它不证明描述符有效，也不证明 child 可以恢复。
+通过 store 创建 `Session` 时会接收 `seed`（初始回放或 fork 历史）与 `meta`（store 折叠进 `SessionHeader` 的存储层字段）。store 填充 `version`/`id` 并为 `createdAt` 提供默认值；调用方可以提供已校验的绝对 `cwd`、`parentSession` 谱系、`seedLength` 种子边界、可选的粗粒度 `origin`、`delegationDepth` 以及已有的 `createdAt`。`origin: 'subagent'` 让产品导航能够隐藏重复的 child 行；它不证明描述符有效，也不证明 child 可以恢复。
 
 ```ts type-equiv
 /**
@@ -110,6 +110,72 @@ interface CreateSessionOptions {
 
 因此，回放/fork 的调用方式为 `ctx.sessions.create(id, { seed: seedEvents })`；将一个*持久化*会话恢复为活跃 agent 的调用方式为 `ctx.agents.resume({ resumeSessionId })`。
 
+## 准备与恢复所有权
+
+`SessionStore.prepare()` 接收普通创建选项，或通过 `RestoredSessionOptions` 转移所有权的新鲜持久化对象图。恢复分支会直接验证并冻结转移来的 header 与事件，因此调用方不得保留可变别名。`SessionPreparation` 随后持有该精确的未发布 Session，直至发布或回滚；dispose 是同步且幂等的。持久化检查只暴露 `SessionInspection`，即从同一个已准备 Session 借用的不可变逻辑视图。
+
+```ts type-equiv
+/**
+ * Fresh storage values transferred to {@link SessionStore.prepare} without a
+ * second serialization copy. Callers retain no mutable aliases.
+ */
+interface RestoredSessionOptions {
+  /** Fresh detached storage events to validate and freeze in place. */
+  readonly seed: SessionEvent[]
+  /** Fresh detached storage metadata to validate and freeze in place. */
+  readonly meta: SessionHeader
+  /** Select the persistence ownership-transfer path. */
+  readonly seedSource: 'persistence'
+}
+```
+
+```ts type-equiv
+/** Inputs accepted while constructing an unpublished Session. */
+type PrepareSessionOptions =
+  | (CreateSessionOptions & { readonly seedSource?: undefined })
+  | RestoredSessionOptions
+```
+
+```ts type-equiv
+/** Options for a preparation whose provider retains unpublished state. */
+interface SessionPreparationOptions {
+  /** Release provider-owned state when the Session was not published. */
+  readonly release?: () => void
+}
+```
+
+```ts public-api
+/**
+ * One exact unpublished Session and the provider state that keeps it usable.
+ * Disposal is synchronous and idempotent. Providers decide whether release
+ * returns the Session to a cache or discards it; publication may consume that
+ * state before disposal, making the callback a no-op.
+ */
+declare class SessionPreparation implements Disposable {
+  /** The exact Session to use for setup and publication. */
+  readonly session: Session;
+  /**
+   * Wrap an unpublished Session in one preparation lifetime.
+   * @param session - exact unpublished Session.
+   * @param options - optional provider release behavior.
+   * @returns a preparation disposed after publication or rollback.
+   */
+  static create(session: Session, options?: SessionPreparationOptions): SessionPreparation;
+  /** Release provider state once when this preparation leaves its caller. */
+  [Symbol.dispose](): void;
+}
+```
+
+```ts type-equiv
+/** Immutable logical session prepared from persistence or a live owner. */
+interface SessionInspection {
+  /** Validated immutable session metadata. */
+  readonly meta: SessionHeader
+  /** Validated contiguous logical event log. */
+  readonly events: readonly SessionEvent[]
+}
+```
+
 ## 轻量源修订号
 
 派生状态的消费方会在加载完整事件日志之前比较一个低开销的不透明修订号。其表示由持久化后端拥有，并随 append 或会修改数据的 load 修复以事务方式改变；调用方仅比较修订号是否相等。
@@ -134,7 +200,7 @@ interface SessionPersistenceSnapshot {
 
 ## 后端
 
-两者都实现同一个抽象 `SessionPersistence`（在 `SessionEvent` 上执行 locate/create/append/load/inspect/list/listSnapshots），并通过 `runPersistenceContract`，证明该 seam 确实与后端无关：
+两者都实现同一个抽象 `SessionPersistence`（在 `SessionEvent` 上执行 locate/create/append/prepare/load/inspect/readFrom/list/listSnapshots，观察方法可选支持取消），并通过 `runPersistenceContract`，证明该 seam 确实与后端无关：
 
 - **[dsh-session-persistence-jsonl](../../packages/session-persistence/session-persistence-jsonl)**——每个会话一份仅追加的逻辑 JSONL 日志，默认存储为带 checksum 的连续 Zstandard frame，也可配置为原始行；支持崩溃安全的原子写入、被中断轮次的恢复以及读取/回放路径。
 - **[dsh-session-persistence-sqlite](../../packages/session-persistence/session-persistence-sqlite)**：基于 `node:sqlite`，每个 `SessionEvent` 一行。行结构 `(session_id, seq, type, time, data, source_event_seqs, surface_op)` 与事件 1:1 映射（包含可选的 surface 元数据），因此没有需要保持同步的并行持久化 schema。

docs/core-data-structures/session.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/core-data-structures/session.md
-session.md: 34e5ad8f7836b18412b7d51a6083e638a3908aae
-session.zh.md: e607e9bb07581c5753b48104993c75586611b675
+session.md: 30f9d7a92f36b0649ec6d61bb3e69a80b125cc73
+session.zh.md: 80762f097bad5f6ab81f3872df5c8b715109241f

docs/core-data-structures/session.md

@@ -400,6 +400,16 @@ declare class Session {
    * @returns a detached session.
    */
   static create(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader): Session;
+  /**
+   * Restore a detached session by taking ownership of fresh persistence values.
+   * Storage shape, event envelopes, sequence continuity, surface transitions,
+   * and header fields are validated before the graphs are frozen in place.
+   * @param id - restored session identity.
+   * @param seed - fresh detached events whose ownership is transferred.
+   * @param header - fresh detached metadata whose ownership is transferred.
+   * @returns a restored detached session.
+   */
+  static fromRestore(id: SessionId, seed: readonly SessionEvent[], header: SessionHeader): Session;
   /**
    * An immutable snapshot of the append-only event log. The snapshot is reused
    * until the next append; a previously returned array does not grow later.

docs/core-data-structures/session.zh.md

@@ -402,6 +402,16 @@ declare class Session {
    * @returns a detached session.
    */
   static create(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader): Session;
+  /**
+   * Restore a detached session by taking ownership of fresh persistence values.
+   * Storage shape, event envelopes, sequence continuity, surface transitions,
+   * and header fields are validated before the graphs are frozen in place.
+   * @param id - restored session identity.
+   * @param seed - fresh detached events whose ownership is transferred.
+   * @param header - fresh detached metadata whose ownership is transferred.
+   * @returns a restored detached session.
+   */
+  static fromRestore(id: SessionId, seed: readonly SessionEvent[], header: SessionHeader): Session;
   /**
    * An immutable snapshot of the append-only event log. The snapshot is reused
    * until the next append; a previously returned array does not grow later.

docs/event-producer-consumer.md

@@ -7,7 +7,7 @@ This matrix shows which packages dispatch each harness-owned event and which pac
 
 | Event | Mode | Declared in | Dispatchers | Listeners |
 | --- | --- | --- | --- | --- |
-| `agent-loop/config-start-failed` | `emit` | [`packages/core/agent-loop/src/index.ts:158`](../packages/core/agent-loop/src/index.ts) | [`agent-loop`](../packages/core/agent-loop) (`events.dispatch`) | - |
+| `agent-loop/config-start-failed` | `emit` | [`packages/core/agent-loop/src/index.ts:182`](../packages/core/agent-loop/src/index.ts) | [`agent-loop`](../packages/core/agent-loop) (`events.dispatch`) | - |
 | `agent/created` | `emit` | [`packages/core/agent/src/types.ts:178`](../packages/core/agent/src/types.ts) | [`agent`](../packages/core/agent) (`events.dispatch`) | [`goal-session`](../packages/goal/goal-session) |
 | `agent/disposed` | `emit` | [`packages/core/agent/src/types.ts:187`](../packages/core/agent/src/types.ts) | [`agent`](../packages/core/agent) (`events.dispatch`) | [`agent-loop`](../packages/core/agent-loop), [`goal-session`](../packages/goal/goal-session), [`subagent`](../packages/subagent/subagent) |
 | `agent/error` | `emit` | [`packages/core/agent/src/types.ts:302`](../packages/core/agent/src/types.ts) | [`agent-loop`](../packages/core/agent-loop) (`emitAgentEvent`) | [`acp`](../packages/acp/acp), `apiproxy`, [`goal-session`](../packages/goal/goal-session), [`session-telemetry`](../packages/telemetry/session-telemetry) |
@@ -30,10 +30,10 @@ This matrix shows which packages dispatch each harness-owned event and which pac
 | `goal/changed` | `emit` | [`packages/goal/goal/src/domain.ts:141`](../packages/goal/goal/src/domain.ts) | [`goal`](../packages/goal/goal) (`emit`) | [`goal-session`](../packages/goal/goal-session) |
 | `llm/adapters-updated` | `emit` | [`packages/llm/llm/src/index.ts:69`](../packages/llm/llm/src/index.ts) | [`llm`](../packages/llm/llm) (`events.dispatch`) | `apiproxy`, [`llm`](../packages/llm/llm) |
 | `llm/stream` | `waterfall` | [`packages/llm/llm/src/index.ts:58`](../packages/llm/llm/src/index.ts) | [`llm`](../packages/llm/llm) (`waterfall`) | [`agent-loop`](../packages/core/agent-loop), [`llm`](../packages/llm/llm), [`llm-replay`](../packages/support/llm-replay), [`session-checkpoint-policy`](../packages/session-persistence/session-checkpoint-policy), [`session-title`](../packages/session-title/session-title) |
-| `session/created` | `emit` | [`packages/core/session/src/index.ts:71`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | `apiproxy`, [`compact`](../packages/compact/compact), [`goal`](../packages/goal/goal), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`llm-retry`](../packages/llm/llm-retry), [`permission`](../packages/ui/permission), [`plan-mode`](../packages/plan/plan-mode), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
-| `session/disposed` | `emit` | [`packages/core/session/src/index.ts:81`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`agent-loop`](../packages/core/agent-loop), `apiproxy`, [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection-cache`](../packages/session-projection/session-projection-cache), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title) |
-| `session/event` | `emit` | [`packages/core/session/src/index.ts:93`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`acp`](../packages/acp/acp), [`agent-loop`](../packages/core/agent-loop), `apiproxy`, [`cli-demo`](../packages/examples/cli-demo), [`compact`](../packages/compact/compact), [`compact-basic`](../packages/compact/compact-basic), [`goal`](../packages/goal/goal), [`goal-session`](../packages/goal/goal-session), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection`](../packages/session-projection/session-projection), [`session-projection-cache`](../packages/session-projection/session-projection-cache), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title), [`token-meter`](../packages/llm/token-meter), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
-| `session/flush` | `parallel` | [`packages/core/session/src/index.ts:102`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry) |
+| `session/created` | `emit` | [`packages/core/session/src/index.ts:73`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | `apiproxy`, [`compact`](../packages/compact/compact), [`goal`](../packages/goal/goal), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`llm-retry`](../packages/llm/llm-retry), [`permission`](../packages/ui/permission), [`plan-mode`](../packages/plan/plan-mode), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
+| `session/disposed` | `emit` | [`packages/core/session/src/index.ts:83`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`agent-loop`](../packages/core/agent-loop), `apiproxy`, [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection-cache`](../packages/session-projection/session-projection-cache), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title) |
+| `session/event` | `emit` | [`packages/core/session/src/index.ts:95`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`acp`](../packages/acp/acp), [`agent-loop`](../packages/core/agent-loop), `apiproxy`, [`cli-demo`](../packages/examples/cli-demo), [`compact`](../packages/compact/compact), [`compact-basic`](../packages/compact/compact-basic), [`goal`](../packages/goal/goal), [`goal-session`](../packages/goal/goal-session), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection`](../packages/session-projection/session-projection), [`session-projection-cache`](../packages/session-projection/session-projection-cache), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title), [`token-meter`](../packages/llm/token-meter), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
+| `session/flush` | `parallel` | [`packages/core/session/src/index.ts:104`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry) |
 | `settings/document-updated` | `emit` | [`packages/settings/settings/src/index.ts:150`](../packages/settings/settings/src/index.ts) | [`settings`](../packages/settings/settings) (`events.dispatch`) | `apiproxy` |
 | `settings/updated` | `emit` | [`packages/settings/settings/src/index.ts:137`](../packages/settings/settings/src/index.ts) | [`settings`](../packages/settings/settings) (`events.dispatch`) | [`settings`](../packages/settings/settings) |
 | `skills/change` | `emit` | [`packages/skill/skill/src/index.ts:188`](../packages/skill/skill/src/index.ts) | [`skill`](../packages/skill/skill) (`events.dispatch`) | - |

docs/persistence-catalog.md

@@ -77,7 +77,7 @@ export type SessionEvent<T extends SessionEventType = SessionEventType> = {
 }[T]
 ```
 
-Sources: [`packages/core/session/src/types.ts:290`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:297`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:325`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:357`](../packages/core/session/src/types.ts)
+Sources: [`packages/core/session/src/types.ts:308`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:315`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:343`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:375`](../packages/core/session/src/types.ts)
 
 ## Events
 
@@ -174,7 +174,7 @@ Source: [`packages/ui/user-approval/src/index.ts:67`](../packages/ui/user-approv
 
 Types: [StreamChunk](core-data-structures/llm-streaming.md)
 
-Source: [`packages/core/session/src/types.ts:220`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:238`](../packages/core/session/src/types.ts)
 
 #### `assistant/message` — surface
 
@@ -190,7 +190,7 @@ Source: [`packages/core/session/src/types.ts:220`](../packages/core/session/src/
 
 Types: [TokenUsage](core-data-structures/llm-streaming.md)
 
-Source: [`packages/core/session/src/types.ts:227`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:245`](../packages/core/session/src/types.ts)
 
 ### `command/*`
 
@@ -419,7 +419,7 @@ Source: [`packages/plan/plan-mode/src/index.ts:52`](../packages/plan/plan-mode/s
 'request/context': RequestContext
 ```
 
-Source: [`packages/core/session/src/types.ts:263`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:281`](../packages/core/session/src/types.ts)
 
 #### `request/header` — log-only
 
@@ -431,7 +431,7 @@ Source: [`packages/core/session/src/types.ts:263`](../packages/core/session/src/
 'request/header': { header: EpochHeader; reason: RequestHeaderReason }
 ```
 
-Source: [`packages/core/session/src/types.ts:258`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:276`](../packages/core/session/src/types.ts)
 
 ### `sandbox/*`
 
@@ -484,7 +484,7 @@ Source: [`packages/sandbox/sandbox-policy/src/session-mode.ts:33`](../packages/s
 'session/end-seed': Record<string, never>
 ```
 
-Source: [`packages/core/session/src/types.ts:286`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:304`](../packages/core/session/src/types.ts)
 
 #### `session/title` — log-only
 
@@ -520,7 +520,7 @@ Source: [`packages/session-title/session-title-llm/src/index.ts:43`](../packages
 'step/end': { turn: number; step: number }
 ```
 
-Source: [`packages/core/session/src/types.ts:210`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:228`](../packages/core/session/src/types.ts)
 
 #### `step/start` — log-only
 
@@ -529,7 +529,7 @@ Source: [`packages/core/session/src/types.ts:210`](../packages/core/session/src/
 'step/start': { turn: number; step: number }
 ```
 
-Source: [`packages/core/session/src/types.ts:208`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:226`](../packages/core/session/src/types.ts)
 
 ### `subagent/*`
 
@@ -559,7 +559,7 @@ Source: [`packages/subagent/subagent/src/descriptor.ts:37`](../packages/subagent
 
 Types: [TodoItem](core-data-structures/session.md)
 
-Source: [`packages/core/session/src/types.ts:253`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:271`](../packages/core/session/src/types.ts)
 
 ### `tool/*`
 
@@ -576,7 +576,7 @@ Source: [`packages/core/session/src/types.ts:253`](../packages/core/session/src/
 
 Types: [CallId](core-data-structures/core.md)
 
-Source: [`packages/core/session/src/types.ts:233`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:251`](../packages/core/session/src/types.ts)
 
 #### `tool/code-dispatch` — log-only
 
@@ -649,7 +649,7 @@ Source: [`packages/core/tools/src/code-mode.ts:33`](../packages/core/tools/src/c
 }
 ```
 
-Source: [`packages/core/session/src/types.ts:245`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:263`](../packages/core/session/src/types.ts)
 
 ### `turn/*`
 
@@ -669,7 +669,7 @@ Source: [`packages/core/session/src/types.ts:245`](../packages/core/session/src/
 
 Types: [TurnEndReason](core-data-structures/session.md)
 
-Source: [`packages/core/session/src/types.ts:206`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:224`](../packages/core/session/src/types.ts)
 
 #### `turn/start` — log-only
 
@@ -683,7 +683,7 @@ Source: [`packages/core/session/src/types.ts:206`](../packages/core/session/src/
 'turn/start': { turn: number }
 ```
 
-Source: [`packages/core/session/src/types.ts:197`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:215`](../packages/core/session/src/types.ts)
 
 ### `user/*`
 
@@ -700,7 +700,7 @@ Source: [`packages/core/session/src/types.ts:197`](../packages/core/session/src/
 'user/message': UserMessage
 ```
 
-Source: [`packages/core/session/src/types.ts:218`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:236`](../packages/core/session/src/types.ts)
 
 ### `web/*`
 

packages/cordis/tool-cordis/src/api-catalog.ts

@@ -581,16 +581,20 @@ export const SERVICE_API: readonly ServiceApiEntry[] = [
         jsDoc: '/**\n * Durably persist a batch of events. Honors the append-only and contiguous-\n * seq contracts: the first event\'s `seq` MUST equal the stored next-seq\n * (after `load` has durably closed any interrupted turn). Rejects non-JSON-\n * serializable `event.data` with an error naming the offending event type.\n * @param id - the session the batch belongs to.\n * @param events - the contiguous batch to persist, in seq order.\n */',
       },
       {
-        signature: 'abstract load(id: SessionId): Promise<{ meta: SessionHeader; events: SessionEvent[] }>',
-        jsDoc: '/**\n * Load a header and balanced contiguous log. A complete interrupted final\n * turn is preserved and durably closed with missing tool errors plus any open\n * step and turn boundaries; only a torn final record is discarded. Unknown\n * versions and corruption in the committed prefix reject. Implementations\n * MUST NOT crash-repair an identity still bound to a live Session: a balanced\n * live log may return with its stored header as a durable snapshot, while an\n * open live turn rejects.\n * A coordinator-backed cold load reserves the identity across storage awaits,\n * so concurrent publication of a same-id live Session rejects.\n * Returned events are detached, and every identified message is deeply\n * frozen. Coordinator-backed implementations upgrade supported pre-identity\n * message events before validation; other malformed messages reject before\n * any stored event is returned.\n * @param id - the persisted session to reload.\n * @returns the header and a log ending on a balanced `turn/end`.\n */',
+        signature: 'async prepare(id: SessionId, signal?: AbortSignal): Promise<SessionPreparation>',
+        jsDoc: '/**\n * Prepare the exact unpublished Session used by resume. Implementations may\n * reuse object graphs retained by an earlier {@link inspect}; disposal\n * releases an unpublished reservation.\n * @param id - persisted session to prepare.\n * @param signal - optional cancellation for preparation work.\n * @returns one owned unpublished Session preparation.\n */',
       },
       {
-        signature: 'abstract inspect(id: SessionId, signal?: AbortSignal): Promise<{ meta: SessionHeader; events: SessionEvent[] }>',
-        jsDoc: '/**\n * Inspect a header and its valid contiguous stored prefix without repairing\n * a torn tail, closing an interrupted turn, or publishing coordinator state.\n * This read is serialized with writes for the same id and returns detached\n * values with upgraded, deeply frozen identified messages, so observers\n * cannot mutate message identity/content or backend-owned state. Other\n * malformed messages reject.\n * @param id - the persisted session to inspect.\n * @param signal - optional cancellation for queued and backend read work.\n * @returns the header and valid stored event prefix exactly as observed.\n */',
+        signature: 'abstract load(id: SessionId): Promise<SessionInspection>',
+        jsDoc: '/**\n * Load an immutable balanced logical view and commit any required cold\n * recovery. A complete interrupted final turn is preserved and durably\n * closed with missing tool errors plus any open step and turn boundaries;\n * only a torn final record is discarded. Unknown versions and corruption in\n * the committed prefix reject. Implementations MUST NOT crash-repair an\n * identity still bound to a live Session: a balanced live log may return as a\n * durable snapshot, while an open live turn rejects. Returned values may be\n * shared with immutable live or prepared state and must not be mutated.\n * @param id - the persisted session to reload.\n * @returns the header and a log ending on a balanced `turn/end`.\n */',
+      },
+      {
+        signature: 'abstract inspect(id: SessionId, signal?: AbortSignal): Promise<SessionInspection>',
+        jsDoc: '/**\n * Inspect an immutable balanced logical session without committing recovery\n * or publishing it. A complete interrupted turn receives synthetic closers\n * in memory and a torn physical tail remains untouched. Coordinator-backed\n * implementations retain the exact unpublished Session for bounded reuse by\n * a later {@link prepare}; callers borrow only its immutable header and log.\n * @param id - the persisted session to inspect.\n * @param signal - optional cancellation for queued and backend read work.\n * @returns the validated header and balanced logical event log.\n */',
       },
       {
         signature: 'abstract readFrom(id: SessionId, fromSeq: number, signal?: AbortSignal): Promise<{ meta: SessionHeader; events: SessionEvent[] }>',
-        jsDoc: '/**\n * Read the stored events from `fromSeq` onward — the read-from-seq\n * primitive for read models that resume from a watermark (e.g. a persisted\n * projection cache folding only the tail past its checkpoint). Like\n * {@link inspect} it is non-mutating and detached: no torn-tail truncation,\n * no synthetic closers, no coordinator-state publication; only events from\n * the valid contiguous stored prefix are returned, so a torn fragment never\n * reaches the caller. `fromSeq` at or beyond the stored prefix returns an\n * empty event list (never an error). Backends whose medium can seek by seq\n * (SQLite) read only the suffix; sequential media (JSONL, both encodings)\n * still parse the whole artifact and skip forward — the primitive bounds\n * what is RETURNED and refolded, not every backend\'s physical read.\n * @param id - the persisted session to read.\n * @param fromSeq - first event seq to include; a non-negative safe integer.\n * @param signal - optional cancellation for queued and backend read work.\n * @returns the header and the stored events with `seq >= fromSeq`.\n */',
+        jsDoc: '/**\n * Read the stored events from `fromSeq` onward — the read-from-seq\n * primitive for read models that resume from a watermark (e.g. a persisted\n * projection cache folding only the tail past its checkpoint). Unlike\n * {@link inspect}, it is a detached physical suffix read: no preparation\n * cache, torn-tail truncation, synthetic closers, or coordinator-state\n * publication. Only events from the valid contiguous stored prefix are\n * returned, so a torn fragment never reaches the caller. `fromSeq` at or\n * beyond the stored prefix returns an empty event list (never an error).\n * Backends whose medium can seek by seq\n * (SQLite) read only the suffix; sequential media (JSONL, both encodings)\n * still parse the whole artifact and skip forward — the primitive bounds\n * what is RETURNED and refolded, not every backend\'s physical read.\n * @param id - the persisted session to read.\n * @param fromSeq - first event seq to include; a non-negative safe integer.\n * @param signal - optional cancellation for queued and backend read work.\n * @returns the header and the stored events with `seq >= fromSeq`.\n */',
       },
       {
         signature: 'abstract list(signal?: AbortSignal): Promise<SessionHeader[]>',
@@ -739,7 +743,7 @@ export const SERVICE_API: readonly ServiceApiEntry[] = [
         jsDoc: '/**\n * Create a session owned by the calling fiber: disposing that fiber stops\n * event notification and removes the session from the store. `options.seed`\n * populates the session with a copy of those events (replay/fork);\n * `options.meta` attaches creation metadata (validated absolute `cwd`, seed\n * and parent lineage, and delegation depth) as the immutable\n * {@link SessionHeader} (the store fills `version`/`id`/`createdAt`).\n *\n * For an agent whose session must be torn down IN ORDER with its loop (so the\n * loop\'s final events are published before the store attachment ends), do NOT use this\n * — fold the session lifecycle into the agent\'s own effect via\n * {@link prepare} + {@link enter} + {@link announce} (see\n * `dsh-agent-loop`\'s creation transaction).\n *\n * @param id - the session id; omitted, the store mints `session-<n>`.\n * @param options - seed events and/or creation metadata for the header.\n * @returns the live session, already entered and announced.\n * @throws if a session with `id` already exists, metadata is not a plain\n *   lossless-JSON record with valid scalar fields, or `meta.cwd` is a\n *   non-absolute path (storage backends key directories off it).\n */',
       },
       {
-        signature: 'prepare(id?: SessionId, options?: CreateSessionOptions): Session',
+        signature: 'prepare(id?: SessionId, options?: PrepareSessionOptions): Session',
         jsDoc: '/**\n * Build a session WITHOUT entering it into the store — validate the id/cwd and\n * construct the {@link Session} (with its immutable {@link SessionHeader}).\n * Pairs with {@link enter} + {@link announce}: a caller that owns a composite\n * `ctx.effect` (the agent factory) folds the session lifecycle into that ONE\n * effect so a fiber unload tears the session + agent down as a single ORDERED\n * chain rather than as racing sibling effects — which would remove the publication hooks\n * before the driver\'s closing events commit, dropping them.\n *\n * @param id - the session id; omitted, the store mints `session-<n>`.\n * @param options - seed events and/or creation metadata for the header.\n * @returns the constructed session, NOT yet in the store.\n * @throws if a session with `id` already exists, metadata is not a plain\n *   lossless-JSON record with valid scalar fields, or `meta.cwd` is a\n *   non-absolute path.\n */',
       },
       {
@@ -2141,6 +2145,10 @@ export const TYPE_API: readonly TypeApiEntry[] = [
     name: 'PreparedReferencedMessage',
     declaration: 'export interface PreparedReferencedMessage {\n    content: ContentBlock[];\n    additionalContext?: UserMessage;\n}',
   },
+  {
+    name: 'PrepareSessionOptions',
+    declaration: 'export type PrepareSessionOptions = (CreateSessionOptions & {\n    readonly seedSource?: undefined;\n}) | RestoredSessionOptions;',
+  },
   {
     name: 'PresetOption',
     declaration: 'export interface PresetOption {\n    value: string;\n    name: string;\n    description?: string;\n}',
@@ -2317,6 +2325,10 @@ export const TYPE_API: readonly TypeApiEntry[] = [
     name: 'ResolvedSubagentStartRequest',
     declaration: 'export interface ResolvedSubagentStartRequest extends SubagentStartRequest {\n    readonly descriptor: SubagentDescriptorData;\n}',
   },
+  {
+    name: 'RestoredSessionOptions',
+    declaration: 'export interface RestoredSessionOptions {\n    readonly seed: SessionEvent[];\n    readonly meta: SessionHeader;\n    readonly seedSource: \'persistence\';\n}',
+  },
   {
     name: 'ResumeAgentOptions',
     declaration: 'export interface ResumeAgentOptions {\n    readonly resumeSessionId: SessionId;\n    readonly agentOptions?: AgentOptions;\n    readonly signal?: AbortSignal;\n    readonly setup?: AgentSetup;\n}',
@@ -2375,7 +2387,7 @@ export const TYPE_API: readonly TypeApiEntry[] = [
   },
   {
     name: 'Session',
-    declaration: 'export class Session {\n    get surface(): SessionSurface;\n    readonly header: SessionHeader;\n    get id(): SessionId;\n    readonly firstLiveSeq: number;\n    static create(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader): Session;\n    get events(): readonly SessionEvent[];\n    get seq(): number;\n    append<T extends SessionEventType>(type: T, data: SessionEventMap[T], ...opts: T extends SurfaceEventType ? [\n        opts: SurfaceIntent\n    ] : [\n    ]): SessionEvent<T>;\n    requestHeader(): EpochHeader | undefined;\n    requestContext(): RequestContext | undefined;\n    deriveMessages(): Message[];\n    deriveEventMessage(event: SessionEvent): Message | null;\n}',
+    declaration: 'export class Session {\n    get surface(): SessionSurface;\n    readonly header: SessionHeader;\n    get id(): SessionId;\n    readonly firstLiveSeq: number;\n    static create(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader): Session;\n    static fromRestore(id: SessionId, seed: readonly SessionEvent[], header: SessionHeader): Session;\n    get events(): readonly SessionEvent[];\n    get seq(): number;\n    append<T extends SessionEventType>(type: T, data: SessionEventMap[T], ...opts: T extends SurfaceEventType ? [\n        opts: SurfaceIntent\n    ] : [\n    ]): SessionEvent<T>;\n    requestHeader(): EpochHeader | undefined;\n    requestContext(): RequestContext | undefined;\n    deriveMessages(): Message[];\n    deriveEventMessage(event: SessionEvent): Message | null;\n}',
   },
   {
     name: 'SessionAvailability',
@@ -2457,6 +2469,10 @@ export const TYPE_API: readonly TypeApiEntry[] = [
     name: 'SessionId',
     declaration: 'export type SessionId = Branded<\'SessionId\'>;',
   },
+  {
+    name: 'SessionInspection',
+    declaration: 'export interface SessionInspection {\n    readonly meta: SessionHeader;\n    readonly events: readonly SessionEvent[];\n}',
+  },
   {
     name: 'SessionLineageNode',
     declaration: 'export interface SessionLineageNode {\n    session: SessionRecord;\n    descendants: SessionLineageNode[];\n}',
@@ -2481,6 +2497,14 @@ export const TYPE_API: readonly TypeApiEntry[] = [
     name: 'SessionPersistenceSnapshot',
     declaration: 'export interface SessionPersistenceSnapshot {\n    header: SessionHeader;\n    revision: SessionPersistenceRevision;\n}',
   },
+  {
+    name: 'SessionPreparation',
+    declaration: 'export class SessionPreparation implements Disposable {\n    readonly session: Session;\n    static create(session: Session, options?: SessionPreparationOptions): SessionPreparation;\n    [Symbol.dispose](): void;\n}',
+  },
+  {
+    name: 'SessionPreparationOptions',
+    declaration: 'export interface SessionPreparationOptions {\n    readonly release?: () => void;\n}',
+  },
   {
     name: 'SessionProjectionMap',
     declaration: 'export interface SessionProjectionMap {\n}',

packages/session-persistence/session-persistence-jsonl/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/session-persistence/session-persistence-jsonl/README.md
-README.md: 7bf6ba2596fb0cf042a2318cfe01f65689131af5
-README.zh.md: afcf06af31ea0f9774d1d6f91310c3493e3eced2
+README.md: 55b802c57c27c771e0259451924501e5fb367911
+README.zh.md: a5e71f27990938576d5a77bf182dbd6919c047f1

packages/session-persistence/session-persistence-jsonl/README.md

@@ -26,6 +26,7 @@ The JSONL durable session-persistence backend — a concrete `SessionPersistence
 | `root` | `string` (required) | Root directory for all session files. **No default** — a `process.cwd()` default would scatter files as the process's cwd changes (bash calls, subprocesses). An existing root must be a readable directory; an absent root is created on first materialization. |
 | `packChunks` | `boolean` (default `true`) | Write eligible delta-chunk runs as packed rows (~60% smaller logical logs measured on a real coding session). Set `false` for one-event-per-line diagnostics; reading packed rows works regardless of this write-side switch. |
 | `compression` | `'zstd' \| 'none'` | Defaults to `'zstd'`; `'none'` retains newline-delimited UTF-8 text. |
+| `preparedSessionCacheSize` | positive integer (default `5`) | Maximum unpublished Sessions retained after cold history inspection for reuse by resume. |
 
 `locate(meta)` returns `{ kind: 'jsonl', path }` for the fixed transcript inside the resolved project/session directories. It performs no filesystem I/O: the target can be returned before the directory or file exists, and an existing file contains only the last flushed prefix.
 
@@ -41,7 +42,7 @@ A root belongs to one encoding. Startup discovery and targeted lookup reject the
 - **Lazy materialization.** `create(meta)` writes nothing; on the first `append`, the backend writes and `fsync`s the encoded header and first batch in a temporary file. POSIX publishes it without overwrite via a hard link and `fsync`s the parent directory. Windows publishes it without overwrite via `MoveFileExW(..., MOVEFILE_WRITE_THROUGH)` and creates missing directories through the same write-through pattern. A created-but-never-appended session leaves nothing on disk and is absent from `list`.
 - **Append-only.** Flushed events are never rewritten. Subsequent raw batches append lines; compressed batches append one frame. Both paths `fsync`, and a caught write or sync failure rolls the file back to its prior byte length.
 - **Crash recovery — preserve valid tail work.** `load` validates every complete compressed frame and scans their decompressed JSONL. If the last frame is structurally incomplete, the reader keeps its complete decoded records, truncates from that frame's start, and re-encodes those records with the synthetic tool, step, and turn closers required by the shared [persistence contract](../../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md). Raw mode truncates from its first incomplete line. A checksum/decompression failure in a complete frame, or a defect at or before the last committed `turn/end`, is corruption and rejects.
-- **Non-mutating inspection.** `inspect()` returns the detached valid prefix without truncating an incomplete tail or closing an interrupted turn, and leaves the lightweight revision unchanged.
+- **Non-mutating inspection.** `inspect()` returns an immutable balanced logical view and may synthesize recovery closers in memory, without truncating an incomplete tail or changing the lightweight revision.
 - **Contiguous-seq.** `append` rejects a batch whose first `seq` does not continue the stored log, and rejects non-JSON-serializable `event.data` naming the offending event type.
 - **Lightweight revisions.** `listSnapshots(signal?)` identifies a log by its device, inode, size, and nanosecond timestamps, avoiding a full-log parse while changing after append, repair, replacement, or store changes. It forwards the exact signal through artifact discovery and checks cancellation around every `stat`; because filesystem `stat` is not interruptible, cancellation waits for the active call to settle, then rejects without starting another.
 

packages/session-persistence/session-persistence-jsonl/README.zh.md

@@ -26,6 +26,7 @@ JSONL 持久会话存储后端：`SessionPersistence` 的一个具体实现（`d
 | `root` | `string`（必需） | 所有会话文件的根目录。**无默认值**：`process.cwd()` 默认值会随进程 cwd 变更（bash 调用、子进程）而分散文件。现有根必须是可读目录；缺失根在第一次实体化时创建。 |
 | `packChunks` | `boolean`（默认 `true`） | 将符合条件的 delta 分片连续段写为打包行（在真实编码会话上测得逻辑日志约小 60%）。设为 `false` 可用于每事件一行诊断；无论该写入侧开关如何，都能读取打包行。 |
 | `compression` | `'zstd' \| 'none'` | 默认 `'zstd'`；`'none'` 保留换行分隔 UTF-8 文本。 |
+| `preparedSessionCacheSize` | 正整数（默认 `5`） | 冷历史检查后保留、供恢复复用的未发布 Session 数量上限。 |
 
 `locate(meta)` 返回已解析项目/会话目录内固定 transcript 的 `{ kind: 'jsonl', path }`。它不执行文件系统 I/O：可以在目录或文件存在前返回目标，现有文件也只包含最近一次 flush 完成的前缀。
 
@@ -41,7 +42,7 @@ JSONL 持久会话存储后端：`SessionPersistence` 的一个具体实现（`d
 - **延迟实体化。**`create(meta)` 不写入；第一次 `append` 将编码 header 和第一批写入临时文件并执行 `fsync`。POSIX 通过硬链接无覆盖发布，并对父目录 `fsync`。Windows 通过 `MoveFileExW(..., MOVEFILE_WRITE_THROUGH)` 无覆盖发布，并通过同一 write-through pattern 创建缺失目录。已创建但从未 append 的会话不留下磁盘内容，不在 `list` 中。
 - **仅追加。** 已 flush 事件绝不重写。后续原始批次 append 行；压缩批次 append 一个 frame。两条路径都执行 `fsync`，并在捕获到写入或同步失败时回滚到之前字节长度。
 - **崩溃恢复：保留有效尾部工作。**`load` 验证每个完整压缩 frame，并扫描解压 JSONL。最后 frame 结构不完整时，读取器保留其完整解码记录，从 frame 开头截断，并使用共享[持久化契约](../../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md) 需要的合成工具、步骤和轮次 closer 重新编码这些记录。原始 mode 从第一个不完整行截断。完整 frame 中的 checksum/解压失败，或位于最后已提交的 `turn/end` 处或之前的缺陷属于损坏，会被拒绝。
-- **非变更检查。**`inspect()` 返回脱离的有效前缀，不截断不完整尾部或关闭中断轮次，并保持轻量修订不变。
+- **非变更检查。**`inspect()` 返回不可变、平衡的逻辑视图，并可在内存中合成恢复 closer，但不会截断不完整尾部或更改轻量修订。
 - **连续 seq。**`append` 拒绝第一个 `seq` 不继续已存储日志的批次，并拒绝非 JSON 可序列化 `event.data`，同时命名违规事件类型。
 - **轻量修订。**`listSnapshots(signal?)` 使用 device、inode、size 和纳秒时间戳标识日志，避免解析完整日志；该标识会在 append、修复、替换或存储变更后改变。它通过产物发现转发精确信号，并在每个 `stat` 前后检查取消；由于文件系统 `stat` 不可中断，取消会等待活动调用完成，然后在不启动另一次调用的情况下拒绝。
 

packages/session-persistence/session-persistence-sqlite/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/session-persistence/session-persistence-sqlite/README.md
-README.md: 394b10a70fc757d75f19178050c0d63699a59e54
-README.zh.md: 6d2a47aa64cee59c35c558e1923a112b0d72f58b
+README.md: de70eb80559611f0409e05d3b2a6f69777a781a6
+README.zh.md: 53df3ef835ebc01b4a1ef7109190c4b64863a5ba

packages/session-persistence/session-persistence-sqlite/README.md

@@ -21,7 +21,7 @@ On filesystems with POSIX modes, the backend requests mode `0700` for missing di
 - **Append = a transaction.** `append` runs `BEGIN`/`COMMIT` around the batch: it materializes the `sessions` row (if still lazy) and INSERTs every event, asserting the contiguous-seq contract first (the first event's `seq` must equal the stored next-seq). A mid-batch failure (a UNIQUE violation on a duplicated seq) rolls back entirely, so the stored log and the in-memory cursor stay consistent. (`load()` already balanced the stored log, so `append` never has to repair a crash tail.)
 - **Lazy materialization.** `create()` records intent in memory only — no row is written until the first `append`. A created-but-never-appended session has no `sessions` row, so it is absent from `list()` (which reports exactly the sessions that have a row).
 - **Interrupted-turn close on load.** `load()` implements the shared [crash-recovery contract](../../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md): preserve the valid interrupted turn, append its synthetic closing events in one transaction, and remove only a torn tail row. Committed parse errors or sequence gaps make the session unloadable. Because recovery mutates stored rows, the next append starts from a balanced log and accurate cursor.
-- **Non-mutating inspection.** `inspect()` returns the detached valid row prefix without deleting a torn tail row or appending recovery closers, and leaves the lightweight revision unchanged.
+- **Non-mutating inspection.** `inspect()` returns an immutable balanced logical view and may synthesize recovery closers in memory, without deleting a torn tail row, appending recovery rows, or changing the lightweight revision.
 - **Lightweight revisions.** `listSnapshots(signal?)` combines the immutable store and database-file identity, a per-materialization incarnation id, and a per-session counter incremented in each mutating transaction. This keeps unchanged observations stable without parsing event rows and distinguishes independent stores and recreated same-id logs. It checks cancellation before and after shared readiness and the synchronous metadata query; the query itself is non-preemptible.
 
 ## Configuration (schemastery)
@@ -30,6 +30,7 @@ On filesystems with POSIX modes, the backend requests mode `0700` for missing di
 interface Config {
   path: string   // SQLite database file path, or ':memory:' for an in-process DB
   journalMode?: 'wal' | 'delete' | 'truncate' | 'persist'   // journal_mode pragma; default 'wal'
+  preparedSessionCacheSize?: number   // positive integer; default 5
 }
 ```
 

packages/session-persistence/session-persistence-sqlite/README.zh.md

@@ -21,7 +21,7 @@ SQLite 持久会话存储后端：第二个 `SessionPersistence` 实现（见[
 - **Append = 事务。**`append` 围绕批次运行 `BEGIN`/`COMMIT`：它实体化 `sessions` 行（如果仍延迟），并 INSERT 每个事件，首先断言连续 seq 契约（第一个事件 `seq` 必须等于已存储 next-seq）。批次中失败（重复 seq 上的 UNIQUE 违规）会完全回滚，使已存储日志和内存游标保持一致。（`load()` 已平衡已存储日志，因此 `append` 不必修复崩溃尾部。）
 - **延迟实体化。**`create()` 只在内存记录意图，第一次 `append` 前不写行。从未 append 的会话没有 `sessions` 行，因此不在 `list()` 中（它精确报告有行的会话）。
 - **在 load 时关闭中断轮次。**`load()` 实现共享[崩溃恢复契约](../../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md)：保留有效中断轮次，在一个事务中追加合成关闭事件，并只移除撕裂尾部行。已提交解析错误或序列缺口使会话无法加载。恢复会变更已存储行，因此下一次 append 从平衡日志和准确游标开始。
-- **非变更检查。**`inspect()` 返回脱离的有效行前缀，不删除撕裂尾部行或追加恢复 closer，并保持轻量修订不变。
+- **非变更检查。**`inspect()` 返回不可变、平衡的逻辑视图，并可在内存中合成恢复 closer，但不会删除撕裂尾部行、追加恢复行或更改轻量修订。
 - **轻量修订。**`listSnapshots(signal?)` 组合不可变存储与数据库文件身份、每实体化 incarnation id，以及在每个变更事务中递增的每会话计数器。它在不解析事件行的情况下保持未变观察稳定，并区分独立存储和重建的同 id 日志。它在共享就绪和同步元数据查询前后检查取消；查询本身不可抢占。
 
 ## 配置（schemastery）
@@ -30,6 +30,7 @@ SQLite 持久会话存储后端：第二个 `SessionPersistence` 实现（见[
 interface Config {
   path: string   // SQLite database file path, or ':memory:' for an in-process DB
   journalMode?: 'wal' | 'delete' | 'truncate' | 'persist'   // journal_mode pragma; default 'wal'
+  preparedSessionCacheSize?: number   // positive integer; default 5
 }
 ```
 

packages/session-persistence/session-persistence/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/session-persistence/session-persistence/README.md
-README.md: 65b50c41670c400284f52c57795b2be49bf21117
-README.zh.md: 7497da2bd6ca03b78d769c1df9995ceb925fdacc
+README.md: 4c00c28184c0046d5507270980822529bfe3bc08
+README.zh.md: 32461cec5efd279a86bf3af40b23e7e54d33a89e

packages/session-persistence/session-persistence/README.md

@@ -13,9 +13,10 @@ The persisted unit IS the existing `SessionEvent` (event-sourced model — the l
 | `locate(meta): SessionLocation \| undefined` | Resolve an absolute per-session artifact target without I/O or materialization. Backends without an independent local artifact return `undefined`. |
 | `create(meta): Promise<void>` | Register a new session's metadata. MAY defer the physical write until the first `append` (lazy materialization). |
 | `append(id, events): Promise<void>` | Durably persist a batch. Append-only; first event `seq` == stored next-seq after any repair; rejects non-JSON-serializable data naming the offending type. |
-| `load(id): Promise<{ meta; events }>` | Return a stored header plus a balanced contiguous log whose events are detached and validated and whose identified messages are deeply frozen. The coordinator upgrades the supported same-version message and pre-react-loop event shapes into the current read snapshot; all other obsolete or malformed shapes still reject. A live load first flushes its snapshot and rejects while its turn is open; a cold load preserves an interrupted final turn and closes it with synthetic `tool/result`/`step/end?`/`turn/end {interrupted}` events. Only a torn tail fragment is dropped; committed corruption and unknown `version` reject. |
-| `inspect(id, signal?): Promise<{ meta; events }>` | Return a detached valid stored prefix with upgraded, validated, deeply frozen identified messages, without truncating a torn tail, synthesizing recovery closers, or publishing coordinator state. Serialized with same-id writes; the optional signal promptly rejects a queued caller, prevents that queued backend read from starting, and cancels active backend read work. Intended for read models and other observers that must never recover a log. |
-| `readFrom(id, fromSeq, signal?): Promise<{ meta; events }>` | The read-from-seq primitive: return the header plus the valid stored events with `seq >= fromSeq`, detached and non-mutating like `inspect` (no truncation, no closers, no coordinator state). A `fromSeq` at or past the stored end returns an empty event list; a negative or non-safe-integer `fromSeq` rejects. Seek-capable backends (SQLite) read only the suffix unless a legacy event in that suffix requires prefix context for normalization; sequential backends (JSONL) parse the whole artifact and skip forward. Intended for checkpoint consumers (e.g. the persisted projection cache) that fold only the tail past a watermark. |
+| `prepare(id, signal?): Promise<SessionPreparation>` | Reserve the exact unpublished Session used by resume. A coordinator reuses an earlier inspection when available, commits pending recovery, and releases an unpublished reservation back to its bounded cache on disposal. |
+| `load(id): Promise<{ meta; events }>` | Return an immutable balanced logical log after supported same-version shape upgrades and commit cold recovery. A live load first flushes its snapshot and rejects while its turn is open; a cold load preserves an interrupted final turn and durably closes it with synthetic `tool/result`/`step/end?`/`turn/end {interrupted}` events. Only a torn tail fragment is dropped; committed corruption, malformed shapes, and unknown `version` reject. |
+| `inspect(id, signal?): Promise<{ meta; events }>` | Return the same upgraded, validated, deeply frozen logical view without committing recovery or publishing a Session. Synthetic recovery closers exist only in memory, the physical torn tail remains untouched, and coordinator-backed implementations retain the exact unpublished Session in a bounded LRU for later `prepare`. Same-id inspections share an in-flight read. |
+| `readFrom(id, fromSeq, signal?): Promise<{ meta; events }>` | The detached physical-suffix primitive: return valid stored events with `seq >= fromSeq` without preparation caching, truncation, closers, or coordinator state. A `fromSeq` at or past the stored end returns an empty event list; a negative or non-safe-integer `fromSeq` rejects. Seek-capable backends (SQLite) read only the suffix unless a supported old shape requires prefix context for normalization; sequential backends (JSONL) parse the whole artifact and skip forward. Intended for checkpoint consumers that fold only the tail past a watermark. |
 | `list(signal?): Promise<SessionHeader[]>` | Lightweight listing from metadata, no full-log parse. The optional signal cancels backend listing work. A zero-event lazily-materialized session is absent from `list`. |
 | `listSnapshots(signal?): Promise<SessionPersistenceSnapshot[]>` | Lightweight metadata plus an opaque branded per-log revision, without loading event logs. A revision stays equal while that log and its backing store are unchanged, changes after append or mutating load repair, and cannot collide solely because two stores use the same local counter. The optional signal requests cancellation of backend discovery work; first-party backends settle any started listing work before rejecting so an awaited call is quiescent. |
 
@@ -32,7 +33,7 @@ The persisted unit IS the existing `SessionEvent` (event-sourced model — the l
 
 Each `session/event` copies its event into the session controller and starts an eager drain without blocking the producer. Concurrent notifications share the current drain; events admitted during a write remain pending and trigger the next batch. `session/flush` is an observation barrier that waits until the controller has no current or pending batch. An eager failure is logged and retains the batch; the next explicit flush or backend teardown retries it and surfaces failure to its caller.
 
-Crash repair is cold-only. For a live id, `load(id)` snapshots the authoritative in-memory log, waits for that snapshot to become durable, and returns it with the coordinator's stored header only when balanced; an open live turn rejects instead of receiving synthetic interruption closers. A cold load reserves its id across backend reads and repair writes, so concurrent publication of a same-id live `Session` rejects and rolls back. HMR adoption reads through `loadStored`, applies the coordinator's cwd check, and never closes the active turn.
+Crash repair is cold-only. For a live id, `load(id)` snapshots the authoritative in-memory log, waits for that snapshot to become durable, and returns it only when balanced; an open live turn rejects instead of receiving synthetic interruption closers. For a cold id, inspection reads, validates, freezes, and constructs one unpublished Session; repeated inspection reuses that object graph. `prepare(id)` reserves the exact Session, commits any pending torn-tail/interrupted-turn repair, and returns it for publication. HMR adoption reads through `loadStored`, applies the coordinator's cwd check, and never closes the active turn.
 
 Backend reads normalize the exact supported same-version shapes before current-shape validation. Pre-identity messages receive the deterministic id `legacy-message:<session-id>:<event-seq>`; a tool-result content replacement inherits its target's imported id. A pre-react-loop `turn/start` loses its obsolete trigger, a removed `steering/message` becomes the same identified `user/message`, and an older `turn/end` maps its terminal reason without inventing unavailable cancellation provenance. The coordinator uses the same normalized view for `load`, `inspect`, `readFrom`, ownerless-state claims, and HMR prefix adoption. Storage remains append-only: reads do not rewrite old records, and later appends use the current shape. These are narrow import exceptions from the [pre-identity message](../../../.agents/notes/implemented/bug-fix/2026-07-28-load-pre-identity-session-messages.md) and [pre-react-loop session](../../../.agents/notes/implemented/bug-fix/2026-08-04-load-pre-react-loop-sessions.md) decisions, not a general v0 migration promise.
 
@@ -52,7 +53,7 @@ The `PersistenceBackend<TornMarker>` hooks (the only seam between the coordinato
 | `list(signal?)` | List all stored metadata, observing optional cancellation. |
 | `close?()` | Optional lifecycle teardown (e.g. close a db handle), awaited after the dispose drain. |
 
-The coordinator asserts the stored id and compares stored/live cwd before repair or live adoption. Its `inspect()` path validates and clones the prefix without calling `commitRepair` or publishing write state. The `tornMarker` is fully OPAQUE: the coordinator only tests `!== undefined` and round-trips it to `commitRepair`, never inspecting its value (the JSONL backend uses the byte offset to truncate to, the SQLite backend the seq to delete from). A third-party backend MAY implement the abstract service directly without the coordinator, but it must provide the same non-mutating inspection and trustworthy lightweight snapshot revisions. See [the write-coordinator Agent Note](../../../.agents/notes/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md).
+The coordinator asserts the stored id and compares stored/live cwd before repair or live adoption. Its `inspect()` path takes ownership of fresh backend values, validates and freezes them once, and retains at most the configured number of unpublished Sessions without calling `commitRepair`. The `tornMarker` is fully OPAQUE: the coordinator only tests `!== undefined` and round-trips it to `commitRepair`, never inspecting its value (the JSONL backend uses the byte offset to truncate to, the SQLite backend the seq to delete from). A third-party backend MAY implement the abstract service directly without the coordinator, but it must provide the same non-mutating inspection and trustworthy lightweight snapshot revisions. See [the write-coordinator Agent Note](../../../.agents/notes/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md).
 
 ## Metadata and location types
 

packages/session-persistence/session-persistence/README.zh.md

@@ -13,9 +13,10 @@
 | `locate(meta): SessionLocation \| undefined` | 在不执行 I/O 或实体化的情况下解析绝对的每会话产物目标。没有独立本地产物的后端返回 `undefined`。 |
 | `create(meta): Promise<void>` | 注册新会话元数据。可以将物理写入延迟到第一次 `append`（延迟实体化）。 |
 | `append(id, events): Promise<void>` | 持久保存一个批次。仅追加；任何修复后，第一个事件 `seq` == 已存储 next-seq；非 JSON 可序列化数据会被拒绝，并命名违规类型。 |
-| `load(id): Promise<{ meta; events }>` | 返回已存储 header 和平衡、连续的日志，其中事件已脱离并验证，带标识的消息已深度冻结。协调器会将受支持的同版本消息形状与 react-loop 重构前的事件形状升级为当前读取快照；其余过时或格式错误的形状仍会被拒绝。实时 load 先 flush 其快照，并在轮次开放时拒绝；冷 load 保留中断的最终轮次，并用合成 `tool/result`/`step/end?`/`turn/end {interrupted}` 事件关闭它。只丢弃撕裂尾部碎片；已提交损坏和未知 `version` 会被拒绝。 |
-| `inspect(id, signal?): Promise<{ meta; events }>` | 返回脱离的有效已存储前缀，其中带标识的消息已经升级、验证并深度冻结；不截断撕裂尾部、合成恢复 closer 或发布协调器状态。它与同 id 写入串行化；可选信号会迅速拒绝已排队调用方，阻止该后端读取启动，并取消活动后端读取工作。用于绝不应恢复日志的读模型和其他观察者。 |
-| `readFrom(id, fromSeq, signal?): Promise<{ meta; events }>` | read-from-seq 原语：返回 header 和 `seq >= fromSeq` 的有效已存储事件，与 `inspect` 同样脱离且非变更（不截断、不合成 closer、不发布协调器状态）。`fromSeq` 达到或超过已存储末尾时返回空事件列表；负数或非安全整数 `fromSeq` 会被拒绝。可寻址后端（SQLite）只读后缀，除非后缀中的旧版事件需要前缀上下文才能完成规范化；顺序后端（JSONL）会解析整个产物并向前跳过。用于从水位续折尾部的 checkpoint 消费方（例如持久投影缓存）。 |
+| `prepare(id, signal?): Promise<SessionPreparation>` | 预留恢复使用的精确未发布 Session。协调器会尽可能复用之前的检查结果、提交待处理恢复，并在 dispose 时将未发布 reservation 释放回有界缓存。 |
+| `load(id): Promise<{ meta; events }>` | 在升级受支持的同版本形状后返回不可变、平衡的逻辑日志，并提交冷恢复。实时 load 先 flush 其快照，并在轮次开放时拒绝；冷 load 保留中断的最终轮次，并用合成 `tool/result`/`step/end?`/`turn/end {interrupted}` 事件持久关闭它。只丢弃撕裂尾部碎片；已提交损坏、格式错误的形状和未知 `version` 会被拒绝。 |
+| `inspect(id, signal?): Promise<{ meta; events }>` | 返回同一份已经升级、验证和深度冻结的逻辑视图，但不提交恢复或发布 Session。合成恢复 closer 只存在于内存，物理撕裂尾部保持不变，基于协调器的实现会在有界 LRU 中保留精确的未发布 Session，供后续 `prepare` 使用。同 id 检查共享进行中的读取。 |
+| `readFrom(id, fromSeq, signal?): Promise<{ meta; events }>` | 脱离的物理后缀原语：返回 `seq >= fromSeq` 的有效已存储事件，不进入 preparation 缓存、不截断、不合成 closer，也不发布协调器状态。`fromSeq` 达到或超过已存储末尾时返回空事件列表；负数或非安全整数 `fromSeq` 会被拒绝。可寻址后端（SQLite）只读后缀，除非受支持的旧形状需要前缀上下文才能完成规范化；顺序后端（JSONL）解析整个产物并向前跳过。用于只续折水位之后尾部的 checkpoint 消费方。 |
 | `list(signal?): Promise<SessionHeader[]>` | 从元数据轻量列出，不解析完整日志。可选信号取消后端列表工作。零事件延迟实体化会话不在 `list` 中。 |
 | `listSnapshots(signal?): Promise<SessionPersistenceSnapshot[]>` | 返回轻量元数据和每份日志一个不透明、带品牌类型的修订值，不加载事件日志。日志及其后端存储不变时，修订保持相等；append 或变更性 load 修复后会改变；不会仅因两个存储使用相同本地计数器而冲突。可选信号请求取消后端发现工作；第一方后端会先等待所有已启动的列出工作结束，再予以拒绝，因此调用返回拒绝时，相关工作已完全停稳。 |
 
@@ -32,7 +33,7 @@
 
 每个 `session/event` 将事件复制到会话 controller，并在不阻塞生产者的情况下立即启动 drain。并发通知共享当前 drain；写入期间接纳的事件保持 pending，并触发下一批。`session/flush` 是观察屏障，会等待 controller 无当前或 pending 批次。即时写入失败会记录日志并保留批次；下一次显式 flush 或后端拆卸会重试该批次，并将失败返回给调用方。
 
-崩溃修复只适用于冷状态。对于实时 id，`load(id)` 为权威内存日志制作快照，等待该快照持久，并只在平衡时将其与协调器已存储 header 一起返回；开放实时轮次会被拒绝，而不会收到合成中断 closer。冷 load 在后端读取和修复写入期间保留 id，因此同 id 实时 `Session` 的并发发布会拒绝并回滚。HMR 接管通过 `loadStored` 读取，应用协调器 cwd 检查，并绝不关闭活动轮次。
+崩溃修复只适用于冷状态。对于实时 id，`load(id)` 为权威内存日志制作快照，等待该快照持久，并只在平衡时返回；开放实时轮次会被拒绝，而不会收到合成中断 closer。对于冷 id，检查只读取、验证、冻结并构造一次未发布 Session；重复检查会复用该对象图。`prepare(id)` 预留精确 Session，提交任何待处理的撕裂尾部或中断轮次修复，并将其返回用于发布。HMR 接管通过 `loadStored` 读取，应用协调器 cwd 检查，并绝不关闭活动轮次。
 
 后端读取会在当前形状验证前，规范化明确受支持的同版本形状。消息标识机制引入前的消息会获得确定性的 id `legacy-message:<session-id>:<event-seq>`；工具结果的内容替换会继承其目标导入后的 id。react-loop 重构前的 `turn/start` 会移除过时的 trigger，已移除的 steering（中途引导）事件 `steering/message` 会转换为同一条带标识的 `user/message`；旧版 `turn/end` 会在不虚构无法获得的取消来源的前提下映射终止原因。协调器对 `load`、`inspect`、`readFrom`、无 owner 状态的认领和 HMR 前缀接管使用同一份规范化视图。存储仍然仅追加：读取不会重写旧记录，此后追加的事件使用当前形状。这些是[消息标识机制引入前的消息](../../../.agents/notes/implemented/bug-fix/2026-07-28-load-pre-identity-session-messages.md)与 [react-loop 重构前会话](../../../.agents/notes/implemented/bug-fix/2026-08-04-load-pre-react-loop-sessions.md)决策所规定的范围受限的导入例外，并不构成通用的 v0 迁移承诺。
 
@@ -52,7 +53,7 @@
 | `list(signal?)` | 列出全部已存储元数据，并遵循可选的取消信号。 |
 | `close?()` | 可选生命周期拆卸（例如关闭 db 句柄），在 dispose drain 后等待。 |
 
-协调器断言已存储 id，并在修复或实时接管前比较已存储/实时 cwd。其 `inspect()` 路径验证并克隆前缀，不调用 `commitRepair` 或发布写入状态。`tornMarker` 完全不透明：协调器只测试 `!== undefined`，并将其原样往返给 `commitRepair`，绝不检查值（JSONL 后端使用待截断字节偏移，SQLite 后端使用待删除 seq）。第三方后端可以不用协调器直接实现抽象服务，但必须提供相同非变更检查和可信轻量快照修订。详见[写入协调器 Agent Note](../../../.agents/notes/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md)。
+协调器断言已存储 id，并在修复或实时接管前比较已存储/实时 cwd。其 `inspect()` 路径取得新鲜后端值的所有权，只验证和冻结一次，并在不调用 `commitRepair` 的情况下最多保留配置数量的未发布 Session。`tornMarker` 完全不透明：协调器只测试 `!== undefined`，并将其原样往返给 `commitRepair`，绝不检查值（JSONL 后端使用待截断字节偏移，SQLite 后端使用待删除 seq）。第三方后端可以不用协调器直接实现抽象服务，但必须提供相同非变更检查和可信轻量快照修订。详见[写入协调器 Agent Note](../../../.agents/notes/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md)。
 
 ## 元数据与位置类型
 

scripts/gen-cordis-catalog.ts

@@ -102,8 +102,11 @@ export const LINK_MAP: Readonly<Record<string, string>> = {
   StreamChunk: 'llm-streaming.md',
   SkillProviderControl: 'skills.md',
   CreateSessionOptions: 'persistence.md',
+  PrepareSessionOptions: 'persistence.md',
   SessionHeader: 'persistence.md',
+  SessionInspection: 'persistence.md',
   SessionLocation: 'persistence.md',
+  SessionPreparation: 'persistence.md',
   SessionPersistenceSnapshot: 'persistence.md',
   ConfinedArgv: 'sandbox.md',
   SandboxExecutionPolicy: 'sandbox.md',

scripts/type-equiv.manifest.json

@@ -399,6 +399,32 @@
       "symbol": "CreateSessionOptions",
       "source": "packages/core/session/src/types.ts"
     },
+    {
+      "doc": "docs/core-data-structures/persistence.md",
+      "symbol": "RestoredSessionOptions",
+      "source": "packages/core/session/src/types.ts"
+    },
+    {
+      "doc": "docs/core-data-structures/persistence.md",
+      "symbol": "PrepareSessionOptions",
+      "source": "packages/core/session/src/types.ts"
+    },
+    {
+      "doc": "docs/core-data-structures/persistence.md",
+      "symbol": "SessionPreparationOptions",
+      "source": "packages/core/session/src/preparation.ts"
+    },
+    {
+      "doc": "docs/core-data-structures/persistence.md",
+      "symbol": "SessionPreparation",
+      "source": "packages/core/session/src/preparation.ts",
+      "projection": "public-api"
+    },
+    {
+      "doc": "docs/core-data-structures/persistence.md",
+      "symbol": "SessionInspection",
+      "source": "packages/session-persistence/session-persistence/src/index.ts"
+    },
     {
       "doc": "docs/core-data-structures/persistence.md",
       "symbol": "SessionLocation",