diff --git a/TODO.md b/TODO.md
index 110beb42..46847bc0 100644
--- a/TODO.md
+++ b/TODO.md
@@ -16,4 +16,4 @@
   - 使用頻度メトリクス + Knowledge 化候補レポート → [tickets/memory-usage-metrics.md](tickets/memory-usage-metrics.md)
 - セッション内 TODO ツール（注意機構付き） → [tickets/session-todo.md](tickets/session-todo.md)
 - ワークスペースのメモリーをLintするヘッドレスCLI
-- system-reminder 注入機構の汎用化（2件目の利用者が出た時に検討。タグ形式と「履歴を汚さない」原則は session-todo で先行確立）
+- system-reminder 注入機構の汎用化（2件目の利用者が出た時に検討。タグ形式 `<system-reminder>...</system-reminder>` の規約は session-todo-reminder で先行確立。注入された Item は worker.history に append する方針）
diff --git a/crates/llm-worker/src/interceptor.rs b/crates/llm-worker/src/interceptor.rs
index 4795d798..9ab8323a 100644
--- a/crates/llm-worker/src/interceptor.rs
+++ b/crates/llm-worker/src/interceptor.rs
@@ -120,8 +120,35 @@ pub trait Interceptor: Send + Sync {
         PromptAction::Continue
     }
 
-    /// Called before each LLM request. The context can be modified
-    /// (e.g. for context compaction).
+    /// Items that should be **committed to `worker.history`** just
+    /// before the next LLM request. Returned items are `extend`ed into
+    /// the persistent history (and therefore picked up by the per-turn
+    /// clone that backs the LLM request, plus the usual
+    /// history-persistence path).
+    ///
+    /// Use this for inputs that arrive from outside the LLM and need
+    /// to be reflected in the on-disk history — notifications,
+    /// cross-Pod events, system reminders. Do **not** use
+    /// [`Self::pre_llm_request`] for that purpose: it mutates a
+    /// per-request clone, so any committed assistant response that
+    /// reacts to the injection would have no visible trigger on the
+    /// next turn (or after resume / compaction).
+    ///
+    /// `pre_llm_request` remains the right place for purely
+    /// reproducible per-request transformations (pruning, content
+    /// trimming, cache anchors) that depend only on the existing
+    /// history.
+    async fn pending_history_appends(&self) -> Vec<Item> {
+        Vec::new()
+    }
+
+    /// Called before each LLM request. The context starts as a clone
+    /// of `worker.history` (after `pending_history_appends` and the
+    /// Worker's own prune projection have been applied) and can be
+    /// further modified for that single request only — mutations here
+    /// are **not** persisted back to history. Use
+    /// [`Self::pending_history_appends`] for inputs that need to land
+    /// in history.
     async fn pre_llm_request(&self, _context: &mut Vec<Item>) -> PreRequestAction {
         PreRequestAction::Continue
     }
diff --git a/crates/llm-worker/src/worker.rs b/crates/llm-worker/src/worker.rs
index fd305e42..6337742f 100644
--- a/crates/llm-worker/src/worker.rs
+++ b/crates/llm-worker/src/worker.rs
@@ -856,6 +856,16 @@ impl<C: LlmClient, S: WorkerState> Worker<C, S> {
                 cb(current_turn);
             }
 
+            // Drain interceptor-side inputs that are meant to land in
+            // history (notifications, cross-Pod events, system
+            // reminders). These are committed *before* the per-request
+            // clone so they participate in the LLM request below and
+            // get persisted by the upper layer that owns history.json.
+            let pending = self.interceptor.pending_history_appends().await;
+            if !pending.is_empty() {
+                self.history.extend(pending);
+            }
+
             // Clone the history into a per-request context. Everything
             // below (prune projection, interceptor hooks) mutates only
             // this clone, so the persistent `self.history` stays intact.
diff --git a/crates/pod/src/ipc/interceptor.rs b/crates/pod/src/ipc/interceptor.rs
index f7b9d9de..7594753d 100644
--- a/crates/pod/src/ipc/interceptor.rs
+++ b/crates/pod/src/ipc/interceptor.rs
@@ -17,6 +17,7 @@ use llm_worker::interceptor::{
     Interceptor, PostToolAction, PreRequestAction, PreToolAction, PromptAction, ToolCallInfo,
     ToolResultInfo, TurnEndAction,
 };
+use tracing::warn;
 use llm_worker::tool::ToolOutput;
 use tracing::info;
 
@@ -28,7 +29,6 @@ use crate::hook::{
 use crate::ipc::notify_buffer::{NotifyBuffer, format_notify};
 use crate::prompt::catalog::PromptCatalog;
 use llm_worker::token_counter::total_tokens;
-use tracing::warn;
 
 /// Maximum number of bytes copied into `TurnEndInfo::final_text_preview`.
 const FINAL_TEXT_PREVIEW_LIMIT: usize = 512;
@@ -40,8 +40,10 @@ pub(crate) struct PodInterceptor {
     /// per-request `context` to estimate current occupancy for threshold
     /// checks. `None` when compaction is disabled (both thresholds unset).
     usage_history: Option<Arc<Mutex<Vec<UsageRecord>>>>,
-    /// Pending-notification buffer drained into the per-request
-    /// context at the head of `pre_llm_request`.
+    /// Pending-notification buffer drained into `worker.history`
+    /// via [`Self::pending_history_appends`] just before the next LLM
+    /// request. The Worker `extend`s these into its persistent history
+    /// so the LLM has a visible trigger for any reaction it commits.
     pending_notifies: NotifyBuffer,
     /// Submit-scoped stash of resolver-produced system messages.
     /// Drained inside `on_prompt_submit` and returned via
@@ -122,6 +124,27 @@ impl Interceptor for PodInterceptor {
         }
     }
 
+    async fn pending_history_appends(&self) -> Vec<Item> {
+        let drained = self.pending_notifies.drain();
+        if drained.is_empty() {
+            return Vec::new();
+        }
+        let mut items = Vec::with_capacity(drained.len());
+        for n in drained {
+            match format_notify(&n, &self.prompts) {
+                Ok(item) => items.push(item),
+                Err(e) => {
+                    // A render failure here would starve the LLM of
+                    // the notify text. Fall back to the raw message
+                    // so the trigger still lands in history.
+                    warn!(error = %e, "failed to render notify_wrapper; using raw message");
+                    items.push(Item::system_message(n.message.clone()));
+                }
+            }
+        }
+        items
+    }
+
     async fn pre_llm_request(&self, context: &mut Vec<Item>) -> PreRequestAction {
         let current_tokens = self.estimated_tokens(context);
 
@@ -140,24 +163,6 @@ impl Interceptor for PodInterceptor {
             }
         }
 
-        // Internal mechanism: drain pending `Method::Notify` notifications
-        // into the per-request context as transient system messages.
-        // These are not persisted to the Worker history; they exist only
-        // for this single LLM request.
-        for n in self.pending_notifies.drain() {
-            match format_notify(&n, &self.prompts) {
-                Ok(item) => context.push(item),
-                Err(e) => {
-                    // A render failure here would starve the LLM of the
-                    // notify text. Fall back to the raw message —
-                    // it still carries the intent, just without the
-                    // wrapper phrasing.
-                    warn!(error = %e, "failed to render notify_wrapper; using raw message");
-                    context.push(Item::system_message(n.message.clone()));
-                }
-            }
-        }
-
         let info = PreRequestInfo {
             item_count: context.len(),
             estimated_tokens: current_tokens,
@@ -406,7 +411,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn pre_llm_request_drains_pending_notifies_into_context() {
+    async fn pending_history_appends_drains_buffer_into_items() {
         let registry = Arc::new(HookRegistryBuilder::new().build());
         let buffer = NotifyBuffer::new();
         buffer.push("first".into());
@@ -420,49 +425,52 @@ mod tests {
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
         );
-        let mut ctx: Vec<Item> = vec![Item::user_message("hi")];
-        let action = interceptor.pre_llm_request(&mut ctx).await;
 
-        assert!(matches!(action, PreRequestAction::Continue));
-        // Original user message preserved, two notifications appended in order.
-        assert_eq!(ctx.len(), 3);
-        let second = ctx[1].as_text().unwrap_or_default();
-        let third = ctx[2].as_text().unwrap_or_default();
+        let items = interceptor.pending_history_appends().await;
+        assert_eq!(items.len(), 2);
+        let first = items[0].as_text().unwrap_or_default();
+        let second = items[1].as_text().unwrap_or_default();
+        assert!(first.contains("[Notification]"));
+        assert!(first.contains("first"));
         assert!(second.contains("[Notification]"));
-        assert!(second.contains("first"));
-        assert!(third.contains("[Notification]"));
-        assert!(third.contains("second"));
-        // Buffer is drained after a single pre_llm_request call.
-        assert!(buffer.is_empty());
+        assert!(second.contains("second"));
+        assert!(
+            buffer.is_empty(),
+            "buffer must be drained after pending_history_appends"
+        );
+
+        // Empty buffer → empty Vec (no synthesised items).
+        let again = interceptor.pending_history_appends().await;
+        assert!(again.is_empty());
     }
 
     #[tokio::test]
-    async fn pre_llm_request_skips_notification_injection_when_yielding() {
-        // When compaction yields, notifications remain in the buffer for
-        // the next pre_llm_request (after compaction + resume).
+    async fn pre_llm_request_does_not_touch_pending_notifies() {
+        // The drain lane has moved to `pending_history_appends`;
+        // `pre_llm_request` must leave the buffer alone and not inject
+        // anything itself.
         let registry = Arc::new(HookRegistryBuilder::new().build());
         let buffer = NotifyBuffer::new();
         buffer.push("msg".into());
 
-        let state = Arc::new(CompactState::new(None, Some(100), 2));
-        let ctx_items = vec![Item::user_message("hi")];
-        let history = usage_handle_with(ctx_items.len(), 200);
-
         let interceptor = PodInterceptor::new(
             registry,
-            Some(state),
-            Some(history),
+            None,
+            None,
             buffer.clone(),
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
         );
-        let mut ctx = ctx_items;
+        let mut ctx: Vec<Item> = vec![Item::user_message("hi")];
         let action = interceptor.pre_llm_request(&mut ctx).await;
 
-        assert!(matches!(action, PreRequestAction::Yield));
-        // Notifications were not drained (still held for post-compact resume).
-        assert_eq!(ctx.len(), 1);
-        assert_eq!(buffer.len(), 1);
+        assert!(matches!(action, PreRequestAction::Continue));
+        assert_eq!(ctx.len(), 1, "pre_llm_request must not append notifies");
+        assert_eq!(
+            buffer.len(),
+            1,
+            "pre_llm_request must not drain the notify buffer"
+        );
     }
 
     #[tokio::test]
diff --git a/crates/pod/src/ipc/notify_buffer.rs b/crates/pod/src/ipc/notify_buffer.rs
index b07c1d8d..2700f2eb 100644
--- a/crates/pod/src/ipc/notify_buffer.rs
+++ b/crates/pod/src/ipc/notify_buffer.rs
@@ -1,9 +1,22 @@
-//! Pending-notify buffer for `Method::Notify`.
+//! Pending-notify buffer for `Method::Notify` and `Method::PodEvent`.
 //!
-//! Notify entries are queued here by the Controller and drained by
-//! `PodInterceptor::pre_llm_request` into the per-request context
-//! (never into the Worker's persistent history). Each queued entry
-//! becomes one `Item::system_message` in the outgoing request.
+//! Entries are queued here by the Controller (on receipt of the
+//! corresponding IPC method) and drained by
+//! `PodInterceptor::pending_history_appends`, which the Worker calls
+//! at the head of each turn loop iteration to `extend` them into the
+//! persistent `worker.history`. Each queued entry becomes one
+//! `Item::system_message`.
+//!
+//! This is the **single lane** for "system messages produced by Pod
+//! state that should land in the next LLM request": Notify, PodEvent,
+//! and any future `<system-reminder>` injection all ride this queue
+//! (or a sibling queue with the same lifecycle). Per
+//! `tickets/notify-history-persist.md` and `AGENTS.md` (LLM コンテキスト
+//! の加工原則), there is **no** "transient, history-skipping" lane —
+//! everything injected into a request is also committed to history so
+//! that any LLM reaction has a visible trigger across turns, resume,
+//! and compaction, and so the Anthropic prompt cache prefix stays
+//! stable across requests.
 
 use std::collections::VecDeque;
 use std::sync::{Arc, Mutex};
@@ -68,9 +81,10 @@ impl NotifyBuffer {
 }
 
 /// Format a single pending notify entry into the `Item::system_message`
-/// that gets injected into the per-request context. The wrapper body
-/// comes from `PodPrompt::NotifyWrapper` so the surrounding phrasing
-/// can be customised via a prompt pack (translation, tone, ...).
+/// that gets appended to `worker.history` just before the next LLM
+/// request. The wrapper body comes from `PodPrompt::NotifyWrapper` so
+/// the surrounding phrasing can be customised via a prompt pack
+/// (translation, tone, ...).
 pub(crate) fn format_notify(
     n: &PendingNotify,
     prompts: &PromptCatalog,
diff --git a/crates/pod/src/pod.rs b/crates/pod/src/pod.rs
index a291885b..35ce31d0 100644
--- a/crates/pod/src/pod.rs
+++ b/crates/pod/src/pod.rs
@@ -539,11 +539,13 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         }
     }
 
-    /// Push a `Method::Notify` entry onto the pending buffer.
+    /// Push a `Method::Notify` (or rendered `Method::PodEvent`) entry
+    /// onto the pending buffer.
     ///
-    /// The notification will be injected as an `Item::system_message`
-    /// into the next outgoing LLM request context (not into history).
-    /// See [`NotifyBuffer`] for overflow behaviour.
+    /// The notification will be appended to `worker.history` as an
+    /// `Item::system_message` just before the next LLM request, via
+    /// `PodInterceptor::pending_history_appends`. See [`NotifyBuffer`]
+    /// for overflow behaviour and the lane-of-record rationale.
     pub fn push_notify(&self, message: String) {
         self.pending_notifies.push(message);
     }
diff --git a/crates/pod/tests/controller_test.rs b/crates/pod/tests/controller_test.rs
index 4603bb16..d8b391e6 100644
--- a/crates/pod/tests/controller_test.rs
+++ b/crates/pod/tests/controller_test.rs
@@ -560,22 +560,37 @@ async fn notify_while_idle_auto_starts_turn_and_injects_system_message() {
     assert_eq!(handle.shared_state.get_status(), PodStatus::Idle);
 
     // Exactly one request was made; it must contain the formatted
-    // notification as the last item (injected into request_context by
-    // PodInterceptor::pre_llm_request).
+    // notification as one of the items (committed to history by
+    // PodInterceptor::pending_history_appends and cloned into the
+    // request context for that turn).
     let requests = client_for_assert.captured_requests();
     assert_eq!(requests.len(), 1, "one LLM call expected");
-    let last_item_text = requests[0]
+    let notify_in_request = requests[0]
         .items
-        .last()
-        .and_then(|i| i.as_text())
-        .unwrap_or_default()
-        .to_string();
+        .iter()
+        .any(|i| i.as_text().is_some_and(|t| t.contains("[Notification]") && t.contains("turn finished")));
     assert!(
-        last_item_text.contains("[Notification]"),
-        "injected system message missing, got: {last_item_text:?}"
+        notify_in_request,
+        "injected system message missing from request, got items: {:?}",
+        requests[0]
+            .items
+            .iter()
+            .filter_map(|i| i.as_text())
+            .collect::<Vec<_>>()
+    );
+
+    // The notification must also be persisted into the Worker history
+    // (and therefore eventually into history.json), per
+    // tickets/notify-history-persist.md.
+    let history = handle.shared_state.history();
+    let notify_in_history = history
+        .iter()
+        .any(|i| i.as_text().is_some_and(|t| t.contains("[Notification]") && t.contains("turn finished")));
+    assert!(
+        notify_in_history,
+        "notify must be committed to worker.history, got items: {:?}",
+        history.iter().filter_map(|i| i.as_text()).collect::<Vec<_>>()
     );
-    assert!(last_item_text.contains("turn finished"));
-    assert!(last_item_text.contains("not a blocking request"));
 }
 
 #[tokio::test]
@@ -630,19 +645,33 @@ async fn pod_event_turn_ended_while_idle_auto_starts_turn_and_injects_system_mes
         1,
         "auto-kick should issue exactly one LLM request"
     );
-    let last_item_text = requests[0]
-        .items
-        .last()
-        .and_then(|i| i.as_text())
-        .unwrap_or_default()
-        .to_string();
+    let event_in_request = requests[0].items.iter().any(|i| {
+        i.as_text().is_some_and(|t| {
+            t.contains("[Notification]") && t.contains("child") && t.contains("finished a turn")
+        })
+    });
     assert!(
-        last_item_text.contains("[Notification]"),
-        "injected system message missing, got: {last_item_text:?}"
+        event_in_request,
+        "rendered TurnEnded text missing from request, got items: {:?}",
+        requests[0]
+            .items
+            .iter()
+            .filter_map(|i| i.as_text())
+            .collect::<Vec<_>>()
     );
+
+    // Same item must be present in worker.history (persisted lane),
+    // not just the per-request clone — see tickets/notify-history-persist.md.
+    let history = handle.shared_state.history();
+    let event_in_history = history.iter().any(|i| {
+        i.as_text().is_some_and(|t| {
+            t.contains("[Notification]") && t.contains("child") && t.contains("finished a turn")
+        })
+    });
     assert!(
-        last_item_text.contains("child") && last_item_text.contains("finished a turn"),
-        "rendered TurnEnded text missing, got: {last_item_text:?}"
+        event_in_history,
+        "PodEvent must be committed to worker.history, got items: {:?}",
+        history.iter().filter_map(|i| i.as_text()).collect::<Vec<_>>()
     );
 }
 
diff --git a/tickets/session-todo.md b/tickets/session-todo.md
index 81994966..6643db08 100644
--- a/tickets/session-todo.md
+++ b/tickets/session-todo.md
@@ -14,8 +14,8 @@
 
 - **保存先は `tools` 層の session-lifetime 状態**。`Tracker` と同じ生存スコープで `Pod` が所有。`Arc<Mutex<Vec<TodoItem>>>` ベースの `TodoStore` を tool に注入する
 - **永続化は専用レーンを持たない**。`tool_call.arguments` がセッションログに既に乗っているため、resume 時には履歴 replay の中で最後の `todo_write` 引数を `TodoStore` に再適用すれば状態が復元される
-- **注意機構は `pre_llm_request` Interceptor**。直近の user message に `<system-reminder>` ブロックを揮発的に append するだけ。履歴・ログには載せない
-- **system-reminder 注入の汎用化はやらない**。利用者が TODO 1個しかない段階で抽象を立てない（CLAUDE.md「概念の追加は不在が問題になってから」）。ただし「タグ形式は `<system-reminder>...</system-reminder>` で揃える」「履歴は汚さない」の2点は本実装で確立し、将来の追加機構が同じ規約に乗れるようにする
+- **注意機構は `Interceptor::pending_history_appends`**。未完了 TODO がある場合に新規 system message Item として `worker.history` に append する。Notify / PodEvent と同じ lane に乗せ、`history.json` への永続化と resume 後の読み戻しは worker.history 経由で自動的についてくる（→ `tickets/notify-history-persist.md`）
+- **system-reminder 注入の汎用化はやらない**。利用者が TODO 1個しかない段階で抽象を立てない（CLAUDE.md「概念の追加は不在が問題になってから」）。ただし「タグ形式は `<system-reminder>...</system-reminder>` で揃える」点は本実装で確立し、将来の追加機構が同じ規約に乗れるようにする
 
 ## 要件
 
@@ -43,19 +43,19 @@
 
 ### 注意機構（Interceptor）
 
-- `pre_llm_request` で `Vec<Item>` を受け取り、未完了 TODO（`pending` または `in_progress`）が 1 件でも存在する場合に発動
-- 直近の user message の content（または content[最終 text part]）の末尾に `<system-reminder>` ブロックを append
-- ブロック内には現在の TODO リストを、status を含む簡潔な形式で列挙
-- 履歴 (`Worker` の保持する `Vec<Item>`) は変更しない。リクエスト送信時の Vec のみ加工
-- TODO が空の場合は何も差し込まない
+- `pending_history_appends` で未完了 TODO（`pending` または `in_progress`）が 1 件でも存在する場合に発動し、`<system-reminder>` ブロックを含む新規 system message Item を返す
+- Worker はこれを `worker.history` に append し、その後の per-request clone でリクエストにも含める。永続化 / resume / compaction は通常 Item と同じ扱い
+- ブロック内には現在の TODO リストを、status を含む簡潔な形式で列挙する
+- TODO が空の場合は空の `Vec<Item>` を返し、何も差し込まない
+- cooldown は idle 期間に1回 + 反応で counter リセットの設計上、reminder の連続注入は構造的に起きない（仮に複数回出ても、それぞれが「その時点での active TODO snapshot」として履歴に並ぶのは因果として正しい）
 
 ## 完了条件
 
 - `todo_write` ツールが builtin tool として登録され、Pod で利用できる
-- LLM が `todo_write` を呼ぶと TodoStore が更新され、その後の `pre_llm_request` で system-reminder として LLM に再提示される
+- LLM が `todo_write` を呼ぶと TodoStore が更新され、その後の `pending_history_appends` で system-reminder Item として `worker.history` に append され、リクエストにも含まれる
 - セッションを resume すると、最後の `todo_write` の状態から再開される
 - compact を跨いでも、未完了 TODO が新セッション冒頭の system message として残る
-- system-reminder の注入は揮発的で、`get_history` / セッションログには現れない
+- 注入された system-reminder Item は `worker.history` / `history.json` / `get_history` のいずれにも現れる（揮発レーンは持たない方針 → `tickets/notify-history-persist.md`）
 - 単体テストで `todo_write` の更新挙動 / replay 復元 / Interceptor の差し込みがカバーされる
 
 ## 範囲外