update: エントリの単数化のフォローアップ

Cargo.lock

@@ -2160,6 +2160,7 @@ dependencies = [
  "manifest",
  "memory",
  "minijinja",
+ "parking_lot",
  "pod-registry",
  "protocol",
  "provider",

crates/pod/Cargo.toml

@@ -30,6 +30,7 @@ memory = { workspace = true }
 workflow-crate = { package = "workflow", path = "../workflow" }
 uuid = { workspace = true, features = ["v7"] }
 session-metrics = { workspace = true }
+parking_lot = "0.12.5"
 
 [dev-dependencies]
 dotenv = "0.15.0"

crates/pod/examples/pod_cli.rs

@@ -48,7 +48,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     // 2. Create a persistent store (temp dir for demo)
     let tmp = tempfile::tempdir()?;
-    let store = FsStore::new(tmp.path()).await?;
+    let store = FsStore::new(tmp.path())?;
 
     // 3. Build the Pod from the single-layer manifest TOML
     let mut pod = Pod::from_manifest_toml(&toml, store).await?;

crates/pod/examples/pod_protocol.rs

@@ -39,7 +39,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let pwd = std::env::current_dir()?;
     let toml = manifest_toml(&pwd);
     let tmp = tempfile::tempdir()?;
-    let store = FsStore::new(tmp.path()).await?;
+    let store = FsStore::new(tmp.path())?;
     let pod = pod::Pod::from_manifest_toml(&toml, store).await?;
 
     let runtime_tmp = tempfile::tempdir()?;

crates/pod/src/controller.rs

@@ -6,14 +6,10 @@ use llm_worker::llm_client::client::LlmClient;
 use session_store::Store;
 use tokio::sync::{broadcast, mpsc, oneshot};
 
-use llm_worker::Item;
-use session_store::LogEntry;
-use session_store::session_log;
-
 use crate::ipc::alerter::Alerter;
 use crate::ipc::notify_buffer::NotifyBuffer;
 use crate::ipc::server::SocketServer;
-use crate::pod::{LogCommand, LogDrainHandle, Pod, PodError, PodRunResult};
+use crate::pod::{Pod, PodError, PodRunResult, SystemItemCommitter};
 use crate::runtime::dir::RuntimeDir;
 use crate::session_log_sink::SessionLogSink;
 use crate::shared_state::PodSharedState;
@@ -165,23 +161,21 @@ impl PodController {
         }])
         .map_err(std::io::Error::other)?;
 
-        // === 1.5. Per-item history-commit drain task ===
+        // === 1.5. Direct writer wiring ===
         //
         // Worker callbacks fire `on_history_append` for each assistant
-        // item / tool result / hook-injected item that lands in
-        // history. The drain task picks them up off an unbounded mpsc
-        // and commits each as a typed `LogEntry` through the sink,
-        // serialised against the same `session_head` lock the Pod uses
-        // for its own commits. This gives mid-turn snapshot visibility:
-        // a late-attaching client sees in-flight tool calls + completed
-        // assistant blocks without waiting for the turn-end persist.
-        let (log_cmd_tx, log_cmd_rx) = mpsc::unbounded_channel::<LogCommand>();
-        let drain_ctx = pod.log_drain_handle();
-        let _drain_task = tokio::spawn(run_log_drain(log_cmd_rx, drain_ctx));
-        pod.attach_log_cmd_tx(log_cmd_tx.clone());
+        // item / tool result that lands in history. With the sync
+        // writer in place, the callback commits each item directly
+        // through a `LogWriterHandle` (no mpsc ferry, no drain task).
+        // The same handle is type-erased into a `SystemItemCommitter`
+        // and handed to the interceptor for `SystemItem` commits, so
+        // assistant / tool / system items all share one commit path.
+        let writer_for_system: Arc<dyn SystemItemCommitter> = Arc::new(pod.log_writer_handle());
+        pod.attach_log_writer(writer_for_system);
+        pod.wire_history_persistence();
 
         // === 2. Worker event bridge wiring ===
-        wire_event_bridges_on_worker(&mut pod, &event_tx, &alerter, log_cmd_tx);
+        wire_event_bridges_on_worker(&mut pod, &event_tx, &alerter);
 
         // === 3. Tool registration (builtin / memory / spawn-orchestration) ===
         let fs_for_view = register_pod_tools(
@@ -263,29 +257,20 @@ impl PodController {
 /// re-publishes a worker-level signal as a `protocol::Event` on `event_tx`
 /// so subscribers (TUI, socket clients) get a single typed stream.
 ///
-/// Also wires `on_history_append` into the per-item drain channel so
-/// every history append observed by the worker becomes a typed
-/// `LogEntry` commit (via the drain task).
+/// `Pod::wire_history_persistence` is called separately to wire the
+/// per-item history commit callback so every assistant / tool item
+/// landing in `worker.history` becomes a singular `LogEntry::AssistantItem`
+/// / `ToolResult` commit through the sync writer.
 fn wire_event_bridges_on_worker<C, St>(
     pod: &mut Pod<C, St>,
     event_tx: &broadcast::Sender<Event>,
     alerter: &Alerter,
-    log_cmd_tx: mpsc::UnboundedSender<LogCommand>,
 ) where
     C: LlmClient + Clone + 'static,
     St: Store + Clone + 'static,
 {
     let worker = pod.worker_mut();
 
-    // Per-history-append → drain channel. Sends are infallible-by-design
-    // here (UnboundedSender never blocks); a closed receiver just means
-    // the controller is shutting down, in which case dropping the item
-    // is acceptable.
-    let drain_tx = log_cmd_tx.clone();
-    worker.on_history_append(move |item| {
-        let _ = drain_tx.send(LogCommand::Item(item.clone()));
-    });
-
     let tx = event_tx.clone();
     worker.on_turn_start(move |turn| {
         let _ = tx.send(Event::TurnStart { turn });
@@ -397,73 +382,6 @@ fn wire_event_bridges_on_worker<C, St>(
     // per-item commit channel is wired at the top of this function.
 }
 
-/// Drain task: consumes `LogCommand::Item` and `LogCommand::Flush`
-/// off the channel and commits each item as a typed `LogEntry` through
-/// the supplied store + sink. Lives as long as the controller; exits
-/// when the sender is dropped (controller shutdown).
-async fn run_log_drain<St>(mut rx: mpsc::UnboundedReceiver<LogCommand>, ctx: LogDrainHandle<St>)
-where
-    St: session_store::Store + Clone + Send + 'static,
-{
-    while let Some(cmd) = rx.recv().await {
-        match cmd {
-            LogCommand::Item(item) => {
-                let Some(entry) = classify_history_item(item) else {
-                    continue;
-                };
-                let mut head = ctx.session_head.lock().await;
-                match session_store::append_entry_with_hash(
-                    &ctx.store,
-                    head.session_id,
-                    &mut head.head_hash,
-                    entry.clone(),
-                )
-                .await
-                {
-                    Ok(_) => {
-                        // Publish under the same critical section view
-                        // a `subscribe_with_snapshot` would observe.
-                        ctx.sink.publish(entry);
-                    }
-                    Err(e) => {
-                        tracing::warn!(error = %e, "drain: append_entry failed; entry dropped");
-                    }
-                }
-            }
-            LogCommand::Flush(ack) => {
-                let _ = ack.send(());
-            }
-        }
-    }
-}
-
-/// Map a single worker-history `Item` to its corresponding `LogEntry`
-/// classification. `None` is the skip signal for `user_message` items —
-/// those are committed via `LogEntry::UserInput` by `Pod::run` at
-/// submit time and would otherwise produce a duplicate entry here.
-fn classify_history_item(item: Item) -> Option<LogEntry> {
-    let ts = session_log::now_millis();
-    if item.is_user_message() {
-        return None;
-    }
-    if item.is_tool_result() {
-        return Some(LogEntry::ToolResults {
-            ts,
-            items: vec![session_store::LoggedItem::from(&item)],
-        });
-    }
-    if item.is_assistant_message() || item.is_tool_call() || item.is_reasoning() {
-        return Some(LogEntry::AssistantItems {
-            ts,
-            items: vec![session_store::LoggedItem::from(&item)],
-        });
-    }
-    Some(LogEntry::HookInjectedItems {
-        ts,
-        items: vec![session_store::LoggedItem::from(&item)],
-    })
-}
-
 /// Register the builtin file-manipulation tools, optional memory tools,
 /// and the Pod-orchestration tools (SpawnPod + comm) on the Pod's
 /// Worker. Returns the `ScopedFs` clone used to attach a `PodFsView` to
@@ -696,9 +614,11 @@ async fn controller_loop<C, St>(
             }
 
             Method::Notify { message } => {
-                let _ = event_tx.send(Event::Notify {
-                    message: message.clone(),
-                });
+                // Client-side live echo is delivered as `Event::SystemItem`
+                // once the interceptor commits the corresponding
+                // `LogEntry::SystemItem` entry — drained out of the
+                // notify buffer + broadcast through the sink. No
+                // separate echo here.
                 pod.push_notify(message);
                 // RUNNING / Paused: the buffer push is the entire
                 // operation; an in-flight turn (or the next
@@ -751,10 +671,12 @@ async fn controller_loop<C, St>(
             Method::ListCompletions { .. } => {}
 
             Method::PodEvent(event) => {
-                // Echo the received event to all subscribers so every
-                // client sees the input that drove any following
-                // auto-kicked turn.
-                let _ = event_tx.send(Event::PodEvent(event.clone()));
+                // Live echo travels through the SystemItem lane: once
+                // the interceptor drains the notify buffer, the
+                // typed `SystemItem::PodEvent` lands as a
+                // `LogEntry::SystemItem` entry and the sink forwards it
+                // to clients as `Event::SystemItem`.
+                //
                 // (1) system side effects — idempotent and tolerant of
                 // out-of-order delivery (e.g. `TurnEnded` arriving
                 // after `ShutDown`).
@@ -765,11 +687,10 @@ async fn controller_loop<C, St>(
                     &self_parent_socket,
                 )
                 .await;
-                // (2) render a one-line summary and push it into the
-                // notification buffer; the next LLM request will
-                // inject it as a system message via
-                // `PodInterceptor::pre_llm_request`.
-                pod.push_notify(crate::ipc::event::render_event(&event));
+                // (2) queue the typed event in the notification buffer;
+                // the next LLM request will inject it as a typed
+                // `SystemItem::PodEvent` via the interceptor drain.
+                pod.push_pod_event_notify(event);
                 // Auto-kick a turn if the Pod is idle so the
                 // notification is not stranded. Matches the
                 // `Method::Notify` idle path.
@@ -902,23 +823,21 @@ where
                         });
                     }
                     Some(Method::Notify { message }) => {
-                        let _ = event_tx.send(Event::Notify {
-                            message: message.clone(),
-                        });
-                        // Route into the buffer; the in-flight turn will
-                        // drain it at its next pre_llm_request.
-                        notify_buffer.push(message);
+                        // Live echo arrives via `Event::SystemItem` once
+                        // the in-flight turn's next `pre_llm_request`
+                        // drains this entry through the interceptor.
+                        notify_buffer.push_notify(message);
                     }
                     Some(Method::ListCompletions { .. }) => {}
                     Some(Method::PodEvent(event)) => {
-                        let _ = event_tx.send(Event::PodEvent(event.clone()));
                         // mpsc is consume-once, so we cannot defer this
                         // to the next main-loop iteration — drop here
                         // would lose the event entirely (children fire
                         // and forget). Apply the side effects inline
-                        // and stage the rendered string on the
-                        // notification buffer so the in-flight turn's
-                        // next `pre_llm_request` surfaces it.
+                        // and stage the typed event on the notification
+                        // buffer so the in-flight turn's next
+                        // `pre_llm_request` surfaces it as a typed
+                        // `SystemItem::PodEvent`.
                         let self_parent_socket = parent_socket.cloned();
                         crate::ipc::event::apply_event_side_effects(
                             &event,
@@ -927,7 +846,7 @@ where
                             &self_parent_socket,
                         )
                         .await;
-                        notify_buffer.push(crate::ipc::event::render_event(&event));
+                        notify_buffer.push_pod_event(event);
                     }
                     None => {
                         let _ = cancel_tx.try_send(());

crates/pod/src/ipc/interceptor.rs

@@ -22,11 +22,14 @@ use tracing::info;
 use tracing::warn;
 
 use crate::compact::state::CompactState;
+use session_store::SystemItem;
+
 use crate::hook::{
     AbortInfo, HookPromptAction, HookRegistry, PreRequestInfo, PromptSubmitInfo, ToolCallSummary,
     ToolResultSummary, TurnEndInfo,
 };
-use crate::ipc::notify_buffer::{NotifyBuffer, format_notify};
+use crate::ipc::notify_buffer::{NotifyBuffer, build_system_item};
+use crate::pod::SystemItemCommitter;
 use crate::prompt::catalog::PromptCatalog;
 use llm_worker::token_counter::total_tokens;
 
@@ -45,13 +48,21 @@ pub(crate) struct PodInterceptor {
     /// 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
-    /// `PromptAction::ContinueWith`. Populated by `Pod::run` immediately
-    /// before handing off to the worker.
-    pending_attachments: Arc<Mutex<Vec<Item>>>,
+    /// Submit-scoped stash of resolver-produced typed system items.
+    /// Drained inside `on_prompt_submit`, committed as
+    /// `LogEntry::SystemItem` entries through `log_writer`, and
+    /// returned to the worker as `Item::system_message` via
+    /// `PromptAction::ContinueWith`. Populated by `Pod::run`
+    /// immediately before handing off to the worker.
+    pending_attachments: Arc<Mutex<Vec<SystemItem>>>,
     /// Prompt catalog used to render the injected notification wrapper.
     prompts: Arc<PromptCatalog>,
+    /// Type-erased commit handle. The interceptor uses it to commit
+    /// `LogEntry::SystemItem` entries directly (sync) before
+    /// returning the corresponding `Item::system_message`s up to the
+    /// worker. `None` in tests / `Pod::new` paths where no writer is
+    /// attached.
+    log_writer: Option<Arc<dyn SystemItemCommitter>>,
     /// Next turn index assigned by `on_prompt_submit`.
     next_turn_index: AtomicUsize,
     /// Tool calls observed in the current turn (reset on each new prompt).
@@ -64,8 +75,9 @@ impl PodInterceptor {
         compact_state: Option<Arc<CompactState>>,
         usage_history: Option<Arc<Mutex<Vec<UsageRecord>>>>,
         pending_notifies: NotifyBuffer,
-        pending_attachments: Arc<Mutex<Vec<Item>>>,
+        pending_attachments: Arc<Mutex<Vec<SystemItem>>>,
         prompts: Arc<PromptCatalog>,
+        log_writer: Option<Arc<dyn SystemItemCommitter>>,
     ) -> Self {
         Self {
             registry,
@@ -74,11 +86,27 @@ impl PodInterceptor {
             pending_notifies,
             pending_attachments,
             prompts,
+            log_writer,
             next_turn_index: AtomicUsize::new(0),
             tool_calls_this_turn: AtomicUsize::new(0),
         }
     }
 
+    /// Commit each `SystemItem` as its own `LogEntry::SystemItem`
+    /// entry through the attached writer (no-op when no writer is
+    /// wired). Sync — writes complete before the matching
+    /// `Item::system_message`s reach the worker via
+    /// `ContinueWith` / `pending_history_appends`, so on-disk order
+    /// matches worker-history order.
+    fn commit_system_items(&self, items: &[SystemItem]) {
+        let Some(writer) = self.log_writer.as_ref() else {
+            return;
+        };
+        for item in items {
+            writer.commit_system_item(item.clone());
+        }
+    }
+
     fn current_turn_index(&self) -> usize {
         self.next_turn_index
             .load(Ordering::Relaxed)
@@ -111,7 +139,7 @@ impl Interceptor for PodInterceptor {
                 return action.into();
             }
         }
-        let extras = std::mem::take(
+        let extras: Vec<SystemItem> = std::mem::take(
             &mut *self
                 .pending_attachments
                 .lock()
@@ -120,7 +148,14 @@ impl Interceptor for PodInterceptor {
         if extras.is_empty() {
             PromptAction::Continue
         } else {
-            PromptAction::ContinueWith(extras)
+            // Commit the typed system items first, then hand the
+            // matching `Item::system_message`s to the worker. Sync
+            // commits land BEFORE the worker pushes its
+            // `Item::system_message`s, so on-disk order matches
+            // worker-history order.
+            let items: Vec<Item> = extras.iter().map(SystemItem::to_history_item).collect();
+            self.commit_system_items(&extras);
+            PromptAction::ContinueWith(items)
         }
     }
 
@@ -129,19 +164,31 @@ impl Interceptor for PodInterceptor {
         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),
+        let mut system_items: Vec<SystemItem> = Vec::with_capacity(drained.len());
+        let mut items: Vec<Item> = Vec::with_capacity(drained.len());
+        for entry in drained {
+            match build_system_item(&entry, &self.prompts) {
+                Ok(system_item) => {
+                    items.push(system_item.to_history_item());
+                    system_items.push(system_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.
+                    // the notify text. Fall back to a raw item so the
+                    // trigger still lands in history; the entry will
+                    // simply be skipped from the SystemItem batch.
                     warn!(error = %e, "failed to render notify_wrapper; using raw message");
-                    items.push(Item::system_message(n.message.clone()));
+                    let fallback = match &entry {
+                        super::notify_buffer::PendingNotify::Notify { message } => message.clone(),
+                        super::notify_buffer::PendingNotify::PodEvent { event } => {
+                            session_store::render_pod_event(event)
+                        }
+                    };
+                    items.push(Item::system_message(fallback));
                 }
             }
         }
+        self.commit_system_items(&system_items);
         items
     }
 
@@ -321,6 +368,7 @@ mod tests {
             NotifyBuffer::new(),
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
+            None,
         );
         let mut ctx = ctx_items;
         let action = interceptor.pre_llm_request(&mut ctx).await;
@@ -346,6 +394,7 @@ mod tests {
             NotifyBuffer::new(),
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
+            None,
         );
         let mut ctx = ctx_items;
         let action = interceptor.pre_llm_request(&mut ctx).await;
@@ -372,6 +421,7 @@ mod tests {
             NotifyBuffer::new(),
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
+            None,
         );
         let mut ctx = ctx_items;
         let action = interceptor.pre_llm_request(&mut ctx).await;
@@ -392,6 +442,7 @@ mod tests {
             NotifyBuffer::new(),
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
+            None,
         );
         let mut ctx: Vec<Item> = Vec::new();
         let action = interceptor.pre_llm_request(&mut ctx).await;
@@ -414,8 +465,8 @@ mod tests {
     async fn pending_history_appends_drains_buffer_into_items() {
         let registry = Arc::new(HookRegistryBuilder::new().build());
         let buffer = NotifyBuffer::new();
-        buffer.push("first".into());
-        buffer.push("second".into());
+        buffer.push_notify("first".into());
+        buffer.push_notify("second".into());
 
         let interceptor = PodInterceptor::new(
             registry,
@@ -424,6 +475,7 @@ mod tests {
             buffer.clone(),
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
+            None,
         );
 
         let items = interceptor.pending_history_appends().await;
@@ -451,7 +503,7 @@ mod tests {
         // anything itself.
         let registry = Arc::new(HookRegistryBuilder::new().build());
         let buffer = NotifyBuffer::new();
-        buffer.push("msg".into());
+        buffer.push_notify("msg".into());
 
         let interceptor = PodInterceptor::new(
             registry,
@@ -460,6 +512,7 @@ mod tests {
             buffer.clone(),
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
+            None,
         );
         let mut ctx: Vec<Item> = vec![Item::user_message("hi")];
         let action = interceptor.pre_llm_request(&mut ctx).await;
@@ -489,6 +542,7 @@ mod tests {
             NotifyBuffer::new(),
             Arc::new(Mutex::new(Vec::new())),
             PromptCatalog::builtins_only().unwrap(),
+            None,
         );
         let mut ctx: Vec<Item> = Vec::new();
         let action = interceptor.pre_llm_request(&mut ctx).await;

crates/pod/src/ipc/notify_buffer.rs

@@ -3,39 +3,48 @@
 //! 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`.
+//! at the head of each turn loop iteration. The drain renders each
+//! pending entry into a typed `SystemItem` (with the `notify_wrapper`
+//! prompt applied), commits a `LogEntry::SystemItem` per entry through
+//! the session-log sink, and returns the corresponding
+//! `Item::system_message`s for the worker to append to its
+//! persistent history.
 //!
 //! 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.
+//! and any future `<system-reminder>` injection all ride this queue.
+//! Per `tickets/notify-history-persist.md` and `AGENTS.md` (LLM
+//! context の加工原則), there is **no** "transient, history-skipping"
+//! lane — everything injected into a request is also committed to
+//! history so 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};
 
-use llm_worker::Item;
+use protocol::PodEvent;
+use session_store::SystemItem;
 use tracing::warn;
 
 use crate::prompt::catalog::{CatalogError, PromptCatalog};
 
-/// Maximum queued notify entries. Oldest entries are dropped beyond this.
+/// Maximum queued pending entries. Oldest entries are dropped beyond this.
 const CAPACITY: usize = 128;
 
-/// One pending notify entry awaiting injection into the next LLM request.
+/// One pending entry awaiting drain into the next LLM request.
+///
+/// The buffer keeps the raw input shape so the drain step can decide
+/// the right `SystemItem` kind (and apply `notify_wrapper` to the
+/// rendered body) at the moment of commit, when the prompt catalog
+/// is available.
 #[derive(Debug, Clone)]
-pub struct PendingNotify {
-    pub message: String,
+pub enum PendingNotify {
+    Notify { message: String },
+    PodEvent { event: PodEvent },
 }
 
-/// Shared, mutex-guarded buffer of pending notify entries.
+/// Shared, mutex-guarded buffer of pending entries.
 ///
 /// Cloned between the Pod (producer) and PodInterceptor (consumer).
 #[derive(Clone, Default)]
@@ -51,26 +60,35 @@ impl NotifyBuffer {
     /// Push a notify entry onto the queue. If the queue is full, the
     /// oldest entry is dropped and a `tracing::warn` is emitted — the
     /// caller should never hit this in normal operation.
-    pub fn push(&self, message: String) {
+    pub fn push_notify(&self, message: String) {
+        self.push_entry(PendingNotify::Notify { message });
+    }
+
+    /// Push a typed pod-event entry onto the queue.
+    pub fn push_pod_event(&self, event: PodEvent) {
+        self.push_entry(PendingNotify::PodEvent { event });
+    }
+
+    fn push_entry(&self, entry: PendingNotify) {
         let mut q = self.inner.lock().expect("notify buffer poisoned");
         if q.len() >= CAPACITY {
             let dropped = q.pop_front();
             warn!(
                 capacity = CAPACITY,
-                dropped_message = dropped.as_ref().map(|n| n.message.as_str()),
+                dropped = ?dropped,
                 "notify buffer overflow; dropped oldest"
             );
         }
-        q.push_back(PendingNotify { message });
+        q.push_back(entry);
     }
 
-    /// Remove and return all pending notify entries in FIFO order.
+    /// Remove and return all pending entries in FIFO order.
     pub fn drain(&self) -> Vec<PendingNotify> {
         let mut q = self.inner.lock().expect("notify buffer poisoned");
         q.drain(..).collect()
     }
 
-    /// Number of pending notify entries. Primarily for tests.
+    /// Number of pending entries. Primarily for tests.
     pub fn len(&self) -> usize {
         self.inner.lock().expect("notify buffer poisoned").len()
     }
@@ -80,17 +98,30 @@ impl NotifyBuffer {
     }
 }
 
-/// Format a single pending notify entry into the `Item::system_message`
-/// 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,
+/// Render one pending entry into a typed `SystemItem`. The
+/// `notify_wrapper` prompt produces the LLM-context body for both
+/// `Notify` (raw message) and `PodEvent` (rendered event line).
+pub(crate) fn build_system_item(
+    entry: &PendingNotify,
     prompts: &PromptCatalog,
-) -> Result<Item, CatalogError> {
-    let text = prompts.notify_wrapper(&n.message)?;
-    Ok(Item::system_message(text))
+) -> Result<SystemItem, CatalogError> {
+    match entry {
+        PendingNotify::Notify { message } => {
+            let body = prompts.notify_wrapper(message)?;
+            Ok(SystemItem::Notification {
+                message: message.clone(),
+                body,
+            })
+        }
+        PendingNotify::PodEvent { event } => {
+            let rendered = session_store::render_pod_event(event);
+            let body = prompts.notify_wrapper(&rendered)?;
+            Ok(SystemItem::PodEvent {
+                event: event.clone(),
+                body,
+            })
+        }
+    }
 }
 
 #[cfg(test)]
@@ -100,12 +131,14 @@ mod tests {
     #[test]
     fn push_then_drain_preserves_order() {
         let buf = NotifyBuffer::new();
-        buf.push("one".into());
-        buf.push("two".into());
+        buf.push_notify("one".into());
+        buf.push_notify("two".into());
         let drained = buf.drain();
         assert_eq!(drained.len(), 2);
-        assert_eq!(drained[0].message, "one");
-        assert_eq!(drained[1].message, "two");
+        match &drained[0] {
+            PendingNotify::Notify { message } => assert_eq!(message, "one"),
+            other => panic!("unexpected: {other:?}"),
+        }
         assert!(buf.is_empty());
     }
 
@@ -113,28 +146,50 @@ mod tests {
     fn capacity_drops_oldest() {
         let buf = NotifyBuffer::new();
         for i in 0..(CAPACITY + 5) {
-            buf.push(format!("msg{i}"));
+            buf.push_notify(format!("msg{i}"));
         }
         let drained = buf.drain();
         assert_eq!(drained.len(), CAPACITY);
-        // Oldest 5 were dropped; first retained is msg5.
-        assert_eq!(drained[0].message, "msg5");
-        assert_eq!(
-            drained[CAPACITY - 1].message,
-            format!("msg{}", CAPACITY + 4)
-        );
+        match &drained[0] {
+            PendingNotify::Notify { message } => assert_eq!(message, "msg5"),
+            other => panic!("unexpected: {other:?}"),
+        }
     }
 
     #[test]
-    fn format_notify_includes_message_and_nonblocking_hint() {
-        let n = PendingNotify {
+    fn build_system_item_for_notify_carries_wrapper_body() {
+        let entry = PendingNotify::Notify {
             message: "hello".into(),
         };
         let catalog = PromptCatalog::builtins_only().unwrap();
-        let item = format_notify(&n, &catalog).unwrap();
-        let text = item.as_text().unwrap_or_default().to_string();
-        assert!(text.contains("[Notification]"));
-        assert!(text.contains("hello"));
-        assert!(text.contains("not a blocking request"));
+        let item = build_system_item(&entry, &catalog).unwrap();
+        match item {
+            SystemItem::Notification { message, body } => {
+                assert_eq!(message, "hello");
+                assert!(body.contains("[Notification]"));
+                assert!(body.contains("hello"));
+                assert!(body.contains("not a blocking request"));
+            }
+            other => panic!("unexpected: {other:?}"),
+        }
+    }
+
+    #[test]
+    fn build_system_item_for_pod_event_wraps_rendered_event_text() {
+        let entry = PendingNotify::PodEvent {
+            event: PodEvent::TurnEnded {
+                pod_name: "child".into(),
+            },
+        };
+        let catalog = PromptCatalog::builtins_only().unwrap();
+        let item = build_system_item(&entry, &catalog).unwrap();
+        match item {
+            SystemItem::PodEvent { event, body } => {
+                assert!(matches!(event, PodEvent::TurnEnded { ref pod_name } if pod_name == "child"));
+                assert!(body.contains("[Notification]"));
+                assert!(body.contains("`child`"));
+            }
+            other => panic!("unexpected: {other:?}"),
+        }
     }
 }

crates/pod/src/ipc/server.rs

@@ -104,25 +104,38 @@ async fn handle_connection(stream: tokio::net::UnixStream, handle: PodHandle) {
             entry = entry_rx.recv() => {
                 match entry {
                     Ok(entry) => {
+                        let outbound = match entry {
+                            session_store::LogEntry::SessionStart { .. } => {
                                 let value = serde_json::to_value(&entry)
                                     .expect("LogEntry is Serialize");
-                        let outbound = match &entry {
-                            session_store::LogEntry::SessionStart { .. } => {
                                 Some(Event::SessionRotated { entry: value })
                             }
-                            session_store::LogEntry::HookInjectedItems { .. } => {
-                                Some(Event::HookInjectedItems { entry: value })
+                            session_store::LogEntry::SystemItem { item, .. } => {
+                                let value = serde_json::to_value(&item)
+                                    .expect("SystemItem is Serialize");
+                                Some(Event::SystemItem { item: value })
+                            }
+                            other => {
+                                // `SessionLogSink::is_live_relevant` keeps
+                                // non-live-relevant variants off the
+                                // broadcast lane; reaching here means the
+                                // two are out of sync and we silently
+                                // dropped a wire event. Log so a future
+                                // regression surfaces instead of vanishing.
+                                tracing::error!(
+                                    entry_kind = ?std::mem::discriminant(&other),
+                                    "session-log broadcast emitted a non-live-relevant entry; \
+                                     sink filter and IPC dispatch are out of sync"
+                                );
+                                None
                             }
-                            // Defensive: should never reach here per
-                            // `SessionLogSink::is_live_relevant`.
-                            _ => None,
                         };
-                        if let Some(event) = outbound
-                            && writer.write(&event).await.is_err()
-                        {
+                        if let Some(event) = outbound {
+                            if writer.write(&event).await.is_err() {
                                 break;
                             }
                         }
+                    }
                     Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => {
                         // Slow client fell behind the broadcast buffer.
                         // Drop the connection so the next reconnect

crates/pod/src/lib.rs

@@ -31,5 +31,5 @@ pub use prompt::system::{SystemPromptContext, SystemPromptError, SystemPromptTem
 pub use protocol::{ErrorCode, Event, Method, PodStatus, TurnResult};
 pub use provider::{ProviderError, build_client};
 pub use runtime::dir::RuntimeDir;
-pub use session_log_sink::{SessionLogSink, SessionLogWriter};
+pub use session_log_sink::SessionLogSink;
 pub use shared_state::PodSharedState;

crates/pod/src/main.rs

@@ -162,7 +162,7 @@ async fn main() -> ExitCode {
             }
         },
     };
-    let store = match FsStore::new(&store_dir).await {
+    let store = match FsStore::new(&store_dir) {
         Ok(s) => s,
         Err(e) => {
             eprintln!("error: failed to initialize store at {store_dir:?}: {e}");

crates/pod/src/pod.rs

@@ -1,46 +1,21 @@
 use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
-use tokio::sync::Mutex as AsyncMutex;
 
 use llm_worker::Item;
 use llm_worker::llm_client::RequestConfig;
 use llm_worker::llm_client::client::LlmClient;
 use llm_worker::state::Mutable;
 use llm_worker::{ToolOutputLimits, UsageRecord, Worker, WorkerError, WorkerResult};
+use parking_lot::Mutex as SyncMutex;
 use session_store::{
-    EntryHash, HashedEntry, LogEntry, PodScopeSnapshot, SessionId, Store, StoreError, session_log,
-    to_logged,
+    EntryHash, HashedEntry, LogEntry, PodScopeSnapshot, SessionId, Store, StoreError, SystemItem,
+    session_log, to_logged,
 };
 use tracing::{info, warn};
 
 use crate::session_log_sink::SessionLogSink;
 
-/// Command sent to the per-Pod history-drain task.
-///
-/// `Item` carries one worker-history append observed via
-/// `Worker::on_history_append`; the drain classifies it into a
-/// `LogEntry::AssistantItems` / `LogEntry::ToolResults` /
-/// `LogEntry::HookInjectedItems` and commits it through the sink.
-/// `Flush(ack)` is the barrier used by `persist_turn` to ensure every
-/// in-flight item is committed before the trailing `TurnEnd` entry
-/// lands.
-#[derive(Debug)]
-pub enum LogCommand {
-    Item(Item),
-    Flush(tokio::sync::oneshot::Sender<()>),
-}
-
-/// State shared between Pod and the controller-spawned history-drain
-/// task: store + session-head lock + broadcast sink. All three are
-/// `Clone`able (the latter two as `Arc` clones, the store per its
-/// `Clone` impl) so handing a copy to the drain task is cheap.
-pub struct LogDrainHandle<St> {
-    pub store: St,
-    pub session_head: Arc<AsyncMutex<SessionHead>>,
-    pub sink: SessionLogSink,
-}
-
 use manifest::{
     Permission, PodManifest, PodManifestConfig, ResolveError, Scope, ScopeConfig, ScopeError,
     ScopeRule, SharedScope, WorkerManifest,
@@ -73,6 +48,61 @@ pub struct SessionHead {
     pub head_hash: Option<EntryHash>,
 }
 
+/// Cheap-cloneable bundle of (store + session-head lock + sink) handed
+/// to the worker callback and the interceptor so they can commit
+/// `LogEntry` values directly without going through an mpsc ferry.
+///
+/// All three fields are `Clone` (the latter two as `Arc` clones, the
+/// store per its `Clone` impl) so the handle itself is a flat triple of
+/// cheap copies.
+#[derive(Clone)]
+pub struct LogWriterHandle<St: Clone> {
+    pub store: St,
+    pub session_head: Arc<SyncMutex<SessionHead>>,
+    pub sink: SessionLogSink,
+}
+
+impl<St> LogWriterHandle<St>
+where
+    St: Store + Clone,
+{
+    /// Append `entry` to the log: disk write → in-memory mirror push →
+    /// broadcast — atomic w.r.t. `subscribe_with_snapshot` callers.
+    pub fn append_entry(&self, entry: LogEntry) -> Result<EntryHash, StoreError> {
+        let mut head = self.session_head.lock();
+        let hash = session_store::append_entry_with_hash(
+            &self.store,
+            head.session_id,
+            &mut head.head_hash,
+            entry.clone(),
+        )?;
+        self.sink.publish(entry);
+        Ok(hash)
+    }
+}
+
+/// Type-erased commit handle for the interceptor. Lets the
+/// interceptor commit `SystemItem`s without being generic over the
+/// concrete `Store` type.
+pub trait SystemItemCommitter: Send + Sync {
+    fn commit_system_item(&self, item: SystemItem);
+}
+
+impl<St> SystemItemCommitter for LogWriterHandle<St>
+where
+    St: Store + Clone + Send + Sync + 'static,
+{
+    fn commit_system_item(&self, item: SystemItem) {
+        let entry = LogEntry::SystemItem {
+            ts: session_log::now_millis(),
+            item,
+        };
+        if let Err(err) = self.append_entry(entry) {
+            warn!(error = %err, "system item commit failed; dropping");
+        }
+    }
+}
+
 /// Pre-LLM-request hook that records `history.len()` at send time into a
 /// shared `UsageTracker`. The on_usage callback later pairs this with the
 /// aggregated UsageEvent to produce one `UsageRecord` per LLM call.
@@ -98,7 +128,7 @@ pub struct Pod<C: LlmClient, St: Store> {
     worker: Option<Worker<C, Mutable>>,
     store: St,
     session_id: SessionId,
-    session_head: Arc<AsyncMutex<SessionHead>>,
+    session_head: Arc<SyncMutex<SessionHead>>,
     /// Absolute working directory of the Pod.
     pwd: PathBuf,
     /// Shared, atomically-swappable view of the Pod's resolved scope.
@@ -158,7 +188,7 @@ pub struct Pod<C: LlmClient, St: Store> {
     /// before handing off to the worker; `PodInterceptor::on_prompt_submit`
     /// drains it and returns `ContinueWith` so the items land in
     /// history right after the user message that referenced them.
-    pending_attachments: Arc<Mutex<Vec<Item>>>,
+    pending_attachments: Arc<Mutex<Vec<SystemItem>>>,
     /// Scope allocation in the machine-wide lock file. `Some` for
     /// Pods built via `from_manifest` / `from_manifest_spawned` /
     /// `restore_from_manifest` (production paths); `None` for the
@@ -230,12 +260,21 @@ pub struct Pod<C: LlmClient, St: Store> {
     /// clients see a `(snapshot, live)` stream consistent with what's
     /// on disk.
     sink: SessionLogSink,
-    /// Sender into the controller-spawned history-drain task.
-    /// `None` when no controller has wired one (tests, low-level Pod
-    /// usage). The drain task is the source of mid-turn `AssistantItems`
-    /// / `ToolResults` / `HookInjectedItems` commits, fed by the
-    /// `Worker::on_history_append` callback.
-    log_cmd_tx: Option<tokio::sync::mpsc::UnboundedSender<LogCommand>>,
+    /// `true` once `wire_history_persistence` has installed the
+    /// `Worker::on_history_append` callback that commits each appended
+    /// item as a singular `LogEntry::AssistantItem` / `ToolResult`
+    /// directly through the writer. Tests that drive `Pod::new` without
+    /// going through the controller leave this `false`; `persist_turn`
+    /// then walks the post-`history_before` slice inline so entries
+    /// still land on disk.
+    history_persistence_wired: bool,
+    /// Type-erased commit handle wired by the controller (or by tests
+    /// via `attach_log_writer`). The interceptor uses it to commit
+    /// `SystemItem`s directly without being generic over `St`. `None`
+    /// in low-level test paths that bypass the controller — those
+    /// paths skip SystemItem disk commits but still see the rendered
+    /// `Item::system_message` in worker history.
+    log_writer: Option<Arc<dyn SystemItemCommitter>>,
 }
 
 impl<C: LlmClient + 'static, St: Store + 'static> Pod<C, St> {
@@ -279,7 +318,7 @@ impl<C: LlmClient + Clone + 'static, St: Store + Clone + 'static> Pod<C, St> {
             alerter: self.alerter.clone(),
             event_tx: self.event_tx.clone(),
             pending_notifies: NotifyBuffer::new(),
-            pending_attachments: Arc::new(Mutex::new(Vec::new())),
+            pending_attachments: Arc::new(Mutex::new(Vec::<SystemItem>::new())),
             scope_allocation: None,
             callback_socket: None,
             prompts: self.prompts.clone(),
@@ -296,21 +335,66 @@ impl<C: LlmClient + Clone + 'static, St: Store + Clone + 'static> Pod<C, St> {
             // (it only reads `worker.history()`), so a fresh sink is
             // fine — nothing observes its broadcast.
             sink: SessionLogSink::new(),
-            log_cmd_tx: None,
+            history_persistence_wired: false,
+            log_writer: None,
         }
     }
 
-    /// Build a `LogDrainHandle` carrying everything the controller's
-    /// drain task needs: store handle, the shared session-head lock,
-    /// and the broadcast sink. All three are cheap clones.
-    pub fn log_drain_handle(&self) -> LogDrainHandle<St> {
-        LogDrainHandle {
+    /// Build a `LogWriterHandle` carrying everything the worker
+    /// callback / interceptor needs to commit `LogEntry` values
+    /// directly: store handle, the shared session-head lock, and the
+    /// broadcast sink. All three are cheap clones.
+    pub fn log_writer_handle(&self) -> LogWriterHandle<St> {
+        LogWriterHandle {
             store: self.store.clone(),
             session_head: self.session_head.clone(),
             sink: self.sink.clone(),
         }
     }
 
+    /// Attach a type-erased system-item commit handle. The controller
+    /// calls this once during spawn so the interceptor can commit
+    /// `SystemItem`s directly without owning a generic store handle.
+    /// Idempotent: subsequent calls overwrite the previous handle.
+    pub fn attach_log_writer(&mut self, writer: Arc<dyn SystemItemCommitter>) {
+        self.log_writer = Some(writer);
+    }
+
+    /// Wire `Worker::on_history_append` to commit each appended item
+    /// directly as a singular `LogEntry::AssistantItem` / `ToolResult`
+    /// through the writer. The controller calls this once per spawned
+    /// Pod after the worker is built; tests that drive `Pod::new` may
+    /// opt in to the same wiring or leave it off (in which case
+    /// `persist_turn`'s inline fallback writes entries at turn end).
+    ///
+    /// `user_message` items are skipped because they are committed
+    /// up-front via `commit_entry(LogEntry::UserInput { segments })`.
+    /// `role:system` items are committed by `PodInterceptor` as typed
+    /// `LogEntry::SystemItem` entries before they reach the worker's
+    /// history (so this callback would otherwise double-write them).
+    pub fn wire_history_persistence(&mut self) {
+        let writer = self.log_writer_handle();
+        self.worker_mut().on_history_append(move |item| {
+            if item.is_user_message() {
+                return;
+            }
+            if matches!(
+                item,
+                Item::Message {
+                    role: llm_worker::Role::System,
+                    ..
+                }
+            ) {
+                return;
+            }
+            let entry = session_store::classify_history_item(item, session_log::now_millis());
+            if let Err(err) = writer.append_entry(entry) {
+                warn!(error = %err, "history append commit failed; dropping");
+            }
+        });
+        self.history_persistence_wired = true;
+    }
+
     pub fn spawn_post_run_memory_jobs(&mut self) {
         // Drop a finished prior handle so we can spawn a fresh task.
         // If the prior task is still running, coalesce by skipping —
@@ -360,7 +444,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
             worker: Some(worker),
             store,
             session_id,
-            session_head: Arc::new(AsyncMutex::new(SessionHead {
+            session_head: Arc::new(SyncMutex::new(SessionHead {
                 session_id,
                 head_hash: None,
             })),
@@ -378,7 +462,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
             alerter: None,
             event_tx: None,
             pending_notifies: NotifyBuffer::new(),
-            pending_attachments: Arc::new(Mutex::new(Vec::new())),
+            pending_attachments: Arc::new(Mutex::new(Vec::<SystemItem>::new())),
             scope_allocation: None,
             callback_socket: None,
             prompts,
@@ -392,7 +476,8 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
             memory_task: None,
             user_segments: Vec::new(),
             sink: SessionLogSink::new(),
-            log_cmd_tx: None,
+            history_persistence_wired: false,
+            log_writer: None,
         };
         pod.apply_permissions_from_manifest();
         pod.apply_prune_from_manifest();
@@ -486,8 +571,8 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
     /// process later exits while children keep their allocations, resume
     /// can restore the narrowed scope instead of reclaiming delegated
     /// writes.
-    pub async fn persist_scope_snapshot(&mut self) -> Result<(), StoreError> {
-        if self.session_head.lock().await.head_hash.is_none() {
+    pub fn persist_scope_snapshot(&mut self) -> Result<(), StoreError> {
+        if self.session_head.lock().head_hash.is_none() {
             return Ok(());
         }
         let snapshot = {
@@ -503,23 +588,21 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
             domain: session_store::POD_SCOPE_EXTENSION_DOMAIN.into(),
             payload,
         })
-        .await
         .map(|_| ())
     }
 
     /// Append `entry` to the session log AND publish it through the
-    /// broadcast sink. Holds the session-head async lock across the
+    /// broadcast sink. Holds the session-head sync lock across the
     /// disk write and the sink publish so subscribers see a gap-free
     /// `(snapshot, live)` stream consistent with what's on disk.
-    pub(crate) async fn commit_entry(&self, entry: LogEntry) -> Result<EntryHash, StoreError> {
-        let mut head = self.session_head.lock().await;
+    pub(crate) fn commit_entry(&self, entry: LogEntry) -> Result<EntryHash, StoreError> {
+        let mut head = self.session_head.lock();
         let hash = session_store::append_entry_with_hash(
             &self.store,
             head.session_id,
             &mut head.head_hash,
             entry.clone(),
-        )
-        .await?;
+        )?;
         self.sink.publish(entry);
         Ok(hash)
     }
@@ -531,15 +614,6 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         self.sink.clone()
     }
 
-    /// Wire a history-drain task. The controller calls this once per
-    /// Pod after the drain task is spawned; the matching mpsc receiver
-    /// drives per-item commits of assistant items / tool results /
-    /// hook-injected items committed by the worker via
-    /// `Worker::on_history_append`.
-    pub fn attach_log_cmd_tx(&mut self, tx: tokio::sync::mpsc::UnboundedSender<LogCommand>) {
-        self.log_cmd_tx = Some(tx);
-    }
-
     /// Cloneable callback handed to dynamic-scope tools. It cannot append
     /// directly to the async store from a sync tool callback, so it records
     /// the latest snapshot and the controller flushes it after the tool
@@ -551,7 +625,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         })
     }
 
-    async fn flush_pending_scope_snapshot(&mut self) -> Result<(), StoreError> {
+    fn flush_pending_scope_snapshot(&mut self) -> Result<(), StoreError> {
         let snapshot = self
             .pending_scope_snapshot
             .lock()
@@ -563,8 +637,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                 ts: session_log::now_millis(),
                 domain: session_store::POD_SCOPE_EXTENSION_DOMAIN.into(),
                 payload,
-            })
-            .await?;
+            })?;
         }
         Ok(())
     }
@@ -726,14 +799,14 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
     /// fail the surrounding turn. On failure the head hash stays put
     /// (the entry is dropped) and a `Warn` alert + `tracing::warn!` are
     /// emitted so the failure isn't completely silent.
-    async fn try_record_metric(&mut self, metric: &session_metrics::Metric) {
+    fn try_record_metric(&mut self, metric: &session_metrics::Metric) {
         let payload = serde_json::to_value(metric).expect("Metric is Serialize");
         let entry = LogEntry::Extension {
             ts: session_log::now_millis(),
             domain: session_metrics::DOMAIN.into(),
             payload,
         };
-        if let Err(err) = self.commit_entry(entry).await {
+        if let Err(err) = self.commit_entry(entry) {
             warn!(name = %metric.name, error = %err, "failed to record session metric; dropping");
             self.alert(
                 AlertLevel::Warn,
@@ -760,7 +833,17 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
     /// `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);
+        self.pending_notifies.push_notify(message);
+    }
+
+    /// Push a typed `PodEvent` entry onto the pending buffer.
+    ///
+    /// Same lifecycle as [`push_notify`](Self::push_notify) but
+    /// preserves the typed `PodEvent` payload so the IPC layer can
+    /// emit `SystemItem::PodEvent { event, body }` with structured
+    /// data for clients.
+    pub fn push_pod_event_notify(&self, event: protocol::PodEvent) {
+        self.pending_notifies.push_pod_event(event);
     }
 
     /// Shared handle to the pending notification buffer.
@@ -892,6 +975,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                 self.pending_notifies.clone(),
                 self.pending_attachments.clone(),
                 self.prompts.clone(),
+                self.log_writer.clone(),
             );
             self.worker_mut().set_interceptor(interceptor);
             self.interceptor_installed = true;
@@ -1032,7 +1116,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         self.ensure_interceptor_installed();
         self.ensure_system_prompt_materialized()?;
         self.cleanup_finished_memory_task();
-        self.ensure_session_head().await?;
+        self.ensure_session_head()?;
         if self.should_pre_run_compact() {
             self.join_memory_task().await;
         }
@@ -1057,12 +1141,12 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         // Persist the user input as typed segments before the worker
         // pushes its flattened copy into history. save_delta deliberately
         // skips the resulting `is_user_message()` item to avoid double-write.
-        self.session_id = self.session_head.lock().await.session_id;
+        self.session_id = self.session_head.lock().session_id;
         self.commit_entry(LogEntry::UserInput {
             ts: session_log::now_millis(),
             segments: input.clone(),
         })
-        .await?;
+        ?;
         self.user_segments.push(input.clone());
 
         // Resolve `@<path>` refs, `#<slug>` Knowledge refs, and `/<slug>`
@@ -1099,7 +1183,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
     /// directory) surface as `AlertLevel::Warn` Alerts and are skipped — the
     /// unresolved placeholder stays in the flattened user message so the LLM
     /// still sees the intent.
-    fn resolve_file_refs(&self, segments: &[Segment]) -> Vec<Item> {
+    fn resolve_file_refs(&self, segments: &[Segment]) -> Vec<SystemItem> {
         let view = crate::fs_view::PodFsView::new(tools::ScopedFs::with_shared_scope(
             self.scope.clone(),
             self.pwd.clone(),
@@ -1110,7 +1194,19 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                 continue;
             };
             match view.resolve_file_ref(path, self.manifest.worker.file_upload.max_bytes) {
-                Ok(item) => out.push(item),
+                Ok(item) => {
+                    // `resolve_file_ref` returns an `Item::system_message`
+                    // whose text already carries the `[File: <path>]` or
+                    // `[Dir: <path>]` header (plus any truncation hint).
+                    // Persist that body verbatim — it is what the LLM
+                    // actually saw, so resume produces byte-identical
+                    // history.
+                    let body = item.as_text().unwrap_or_default().to_string();
+                    out.push(SystemItem::FileAttachment {
+                        path: path.clone(),
+                        body,
+                    });
+                }
                 Err(e) => {
                     self.alert(
                         AlertLevel::Warn,
@@ -1123,7 +1219,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         out
     }
 
-    fn resolve_knowledge_refs(&self, segments: &[Segment]) -> Vec<Item> {
+    fn resolve_knowledge_refs(&self, segments: &[Segment]) -> Vec<SystemItem> {
         let Some(layout) = self.memory_layout.as_ref() else {
             return Vec::new();
         };
@@ -1156,7 +1252,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                 }
             };
             let raw = String::from_utf8_lossy(&bytes).into_owned();
-            let body = match memory::schema::split_frontmatter(&raw) {
+            let body_text = match memory::schema::split_frontmatter(&raw) {
                 Ok((_yaml, body)) => body,
                 Err(e) => {
                     self.alert(
@@ -1173,11 +1269,11 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                 &bytes,
             );
             self.append_memory_use_event(memory::UsageSource::KnowledgeRef, vec![snapshot]);
-            out.push(Item::system_message(format!(
-                "[Knowledge #{}]\n{}",
-                slug,
-                body.trim_end()
-            )));
+            let body = format!("[Knowledge #{}]\n{}", slug, body_text.trim_end());
+            out.push(SystemItem::Knowledge {
+                slug: slug.clone(),
+                body,
+            });
         }
         out
     }
@@ -1247,7 +1343,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
     fn resolve_workflow_invocations(
         &self,
         segments: &[Segment],
-    ) -> Result<Vec<Item>, WorkflowResolveError> {
+    ) -> Result<Vec<SystemItem>, WorkflowResolveError> {
         let Some(layout) = self.memory_layout.as_ref() else {
             if let Some(slug) = segments.iter().find_map(|seg| match seg {
                 Segment::WorkflowInvoke { slug } => Some(slug.clone()),
@@ -1282,7 +1378,17 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                     warn!(workflow = %slug, error = %err, "failed to snapshot workflow usage");
                 }
             }
-            out.extend(items);
+            // `resolve_workflow_invocation` returns Item::system_message
+            // entries (potentially multiple — body + dependency knowledge
+            // bodies). Persist each as a SystemItem::Workflow keyed on
+            // the invocation slug.
+            for item in items {
+                let body = item.as_text().unwrap_or_default().to_string();
+                out.push(SystemItem::Workflow {
+                    slug: slug.clone(),
+                    body,
+                });
+            }
         }
         Ok(out)
     }
@@ -1405,11 +1511,11 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
     /// `ensure_system_prompt_materialized` has just rendered. Subsequent
     /// calls fall through to `ensure_head_or_fork`, which auto-forks when
     /// another writer has advanced the store head behind our back.
-    async fn ensure_session_head(&mut self) -> Result<(), PodError> {
+    fn ensure_session_head(&mut self) -> Result<(), PodError> {
         let w = self.worker.as_ref().unwrap();
         let prev_session_id;
         let initial_state = {
-            let head = self.session_head.lock().await;
+            let head = self.session_head.lock();
             prev_session_id = head.session_id;
             head.head_hash.is_none()
         };
@@ -1422,17 +1528,16 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                 forked_from: None,
                 compacted_from: None,
             };
-            self.commit_entry(initial).await?;
-            self.persist_scope_snapshot().await?;
+            self.commit_entry(initial)?;
+            self.persist_scope_snapshot()?;
             return Ok(());
         }
         // Check store head + auto-fork if it drifted.
         let store_head = self
             .store
             .read_head_hash(prev_session_id)
-            .await
             .map_err(PodError::from)?;
-        let mut head = self.session_head.lock().await;
+        let mut head = self.session_head.lock();
         if store_head == head.head_hash {
             return Ok(());
         }
@@ -1456,7 +1561,6 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         };
         self.store
             .create_session(fork_id, &[hashed])
-            .await
             .map_err(PodError::from)?;
         head.session_id = fork_id;
         head.head_hash = Some(hash);
@@ -1600,83 +1704,52 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         history_before: usize,
         result: &Result<WorkerResult, WorkerError>,
     ) -> Result<(), StoreError> {
-        // Per-item commits for AssistantItems / ToolResults /
-        // HookInjectedItems already landed mid-turn through the
-        // controller-spawned drain task, fed by
-        // `Worker::on_history_append`. Drain the queue here so every
-        // in-flight item has actually been committed before the
-        // trailing `TurnEnd` entry. When no drain is wired (low-level
-        // tests / direct `Pod::new` usage) we fall back to a synchronous
-        // pass that replicates the legacy `save_delta` classification —
-        // those code paths don't fire `on_history_append`, so the items
-        // would otherwise be lost.
-        let _ = history_before; // referenced only by the fallback below.
-        self.session_id = self.session_head.lock().await.session_id;
-        if let Some(tx) = self.log_cmd_tx.as_ref() {
-            let (ack_tx, ack_rx) = tokio::sync::oneshot::channel();
-            if tx.send(LogCommand::Flush(ack_tx)).is_ok() {
-                let _ = ack_rx.await;
-            }
-        } else {
-            // Fallback path for tests / Pod::new: classify and commit
-            // the post-`history_before` slice inline, matching the old
-            // `save_delta` shape.
+        // Per-item commits for AssistantItem / ToolResult / SystemItem
+        // entries are expected to have landed synchronously: the
+        // worker `on_history_append` callback (wired by the controller
+        // via `wire_history_persistence`) commits each appended item
+        // directly through the writer, and the interceptor commits
+        // SystemItem entries up-front in `on_prompt_submit` /
+        // `pending_history_appends` before returning the matching
+        // `Item::system_message`s.
+        //
+        // Low-level test paths that build `Pod::new` without wiring
+        // the callback fall through this branch: they classify the
+        // slice from `history_before` inline so the test's
+        // `restore`-style assertions still see entries on disk.
+        self.session_id = self.session_head.lock().session_id;
+        if !self.history_persistence_wired {
             let new_items: Vec<Item> = self.worker.as_ref().unwrap().history()[history_before..]
                 .iter()
                 .cloned()
                 .collect();
             let ts = session_log::now_millis();
-            let mut i = 0;
-            while i < new_items.len() {
-                let item = &new_items[i];
+            for item in &new_items {
                 if item.is_user_message() {
-                    i += 1;
-                } else if item.is_tool_result() {
-                    let start = i;
-                    while i < new_items.len() && new_items[i].is_tool_result() {
-                        i += 1;
+                    continue;
                 }
-                    let items = new_items[start..i]
-                        .iter()
-                        .map(session_store::LoggedItem::from)
-                        .collect();
-                    self.commit_entry(LogEntry::ToolResults { ts, items })
-                        .await?;
-                } else if item.is_assistant_message() || item.is_tool_call() || item.is_reasoning()
-                {
-                    let start = i;
-                    while i < new_items.len()
-                        && (new_items[i].is_assistant_message()
-                            || new_items[i].is_tool_call()
-                            || new_items[i].is_reasoning())
-                    {
-                        i += 1;
+                if matches!(
+                    item,
+                    Item::Message {
+                        role: llm_worker::Role::System,
+                        ..
                     }
-                    let items = new_items[start..i]
-                        .iter()
-                        .map(session_store::LoggedItem::from)
-                        .collect();
-                    self.commit_entry(LogEntry::AssistantItems { ts, items })
-                        .await?;
-                } else {
-                    self.commit_entry(LogEntry::HookInjectedItems {
-                        ts,
-                        items: vec![session_store::LoggedItem::from(&new_items[i])],
-                    })
-                    .await?;
-                    i += 1;
+                ) {
+                    continue;
                 }
+                let entry = session_store::classify_history_item(item, ts);
+                self.commit_entry(entry)?;
             }
         }
 
-        self.flush_pending_scope_snapshot().await?;
+        self.flush_pending_scope_snapshot()?;
 
         let turn_count = self.worker.as_ref().unwrap().turn_count();
         self.commit_entry(LogEntry::TurnEnd {
             ts: session_log::now_millis(),
             turn_count,
         })
-        .await?;
+        ?;
 
         // Flush any sync-buffered metrics from this run first
         // (currently `prune.fire` / `prune.skip` from the prune observer).
@@ -1692,7 +1765,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         // by this point, and `save_run_completed` still needs to land).
         let pending_metrics = self.metrics_tracker.drain();
         for metric in pending_metrics {
-            self.try_record_metric(&metric).await;
+            self.try_record_metric(&metric);
         }
 
         // Persist any LLM Usage measurements collected during this run.
@@ -1717,14 +1790,14 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                 cache_write_tokens: record.cache_write_tokens,
                 output_tokens: record.output_tokens,
             })
-            .await?;
+            ?;
             if let Some(id) = correlation_id {
                 let metric = session_metrics::Metric::now("prune.post_request")
                     .with_correlation_id(&id)
                     .with_value(record.cache_read_tokens as f64)
                     .with_dimension("cache_write_tokens", record.cache_write_tokens.to_string())
                     .with_dimension("history_len", record.history_len.to_string());
-                self.try_record_metric(&metric).await;
+                self.try_record_metric(&metric);
             }
             self.usage_history
                 .lock()
@@ -1740,7 +1813,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                     interrupted,
                     result: r.clone(),
                 })
-                .await?;
+                ?;
             }
             Err(e) => {
                 self.commit_entry(LogEntry::RunErrored {
@@ -1748,7 +1821,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                     interrupted,
                     message: e.to_string(),
                 })
-                .await?;
+                ?;
             }
         }
 
@@ -1982,7 +2055,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         // `SessionStart { compacted_from }` and reset their view.
         let new_session_id = session_store::new_session_id();
         let session_start = {
-            let mut head = self.session_head.lock().await;
+            let mut head = self.session_head.lock();
             let old_session_id = head.session_id;
             let old_head_hash = head
                 .head_hash
@@ -2006,7 +2079,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
                 prev_hash: None,
                 entry: entry.clone(),
             };
-            self.store.create_session(new_session_id, &[hashed]).await?;
+            self.store.create_session(new_session_id, &[hashed])?;
             head.session_id = new_session_id;
             head.head_hash = Some(hash);
             self.session_id = new_session_id;
@@ -2054,7 +2127,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
             .lock()
             .expect("usage_history poisoned")
             .clear();
-        self.persist_scope_snapshot().await?;
+        self.persist_scope_snapshot()?;
         // Reset extract pointer alongside usage_history: the compacted
         // session has a fresh log with no `LogEntry::Extension` entries
         // yet, so a cold restore here would set extract_pointer to None
@@ -2216,7 +2289,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
         // Read the session log to get the current entry count. This is
         // the boundary for the source.range end_entry. Called once per
         // extract, on a small local file.
-        let entries_now = self.store.read_all(self.session_id).await?.len();
+        let entries_now = self.store.read_all(self.session_id)?.len();
         if entries_now == 0 {
             return Ok(ExtractDecision::Skipped);
         }
@@ -2284,7 +2357,7 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
             extract::ExtractedPayload::default()
         });
 
-        let source_session_id = self.session_head.lock().await.session_id;
+        let source_session_id = self.session_head.lock().session_id;
         let staging_id = if payload.is_empty() {
             String::new()
         } else {
@@ -2309,8 +2382,8 @@ impl<C: LlmClient, St: Store> Pod<C, St> {
             domain: extract::EXTRACT_DOMAIN.into(),
             payload: payload_value,
         })
-        .await?;
-        self.session_id = self.session_head.lock().await.session_id;
+        ?;
+        self.session_id = self.session_head.lock().session_id;
 
         *self
             .extract_pointer
@@ -2617,7 +2690,7 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             worker: Some(worker),
             store,
             session_id,
-            session_head: Arc::new(AsyncMutex::new(SessionHead {
+            session_head: Arc::new(SyncMutex::new(SessionHead {
                 session_id,
                 head_hash: None,
             })),
@@ -2635,7 +2708,7 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             alerter: None,
             event_tx: None,
             pending_notifies: NotifyBuffer::new(),
-            pending_attachments: Arc::new(Mutex::new(Vec::new())),
+            pending_attachments: Arc::new(Mutex::new(Vec::<SystemItem>::new())),
             scope_allocation: Some(scope_allocation),
             callback_socket: None,
             prompts: common.prompts,
@@ -2649,7 +2722,8 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             memory_task: None,
             user_segments: Vec::new(),
             sink: SessionLogSink::new(),
-            log_cmd_tx: None,
+            history_persistence_wired: false,
+            log_writer: None,
         };
         pod.apply_permissions_from_manifest();
         pod.apply_prune_from_manifest();
@@ -2690,7 +2764,7 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             worker: Some(worker),
             store,
             session_id,
-            session_head: Arc::new(AsyncMutex::new(SessionHead {
+            session_head: Arc::new(SyncMutex::new(SessionHead {
                 session_id,
                 head_hash: None,
             })),
@@ -2708,7 +2782,7 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             alerter: None,
             event_tx: None,
             pending_notifies: NotifyBuffer::new(),
-            pending_attachments: Arc::new(Mutex::new(Vec::new())),
+            pending_attachments: Arc::new(Mutex::new(Vec::<SystemItem>::new())),
             scope_allocation: Some(scope_allocation),
             callback_socket: Some(callback_socket),
             prompts: common.prompts,
@@ -2722,7 +2796,8 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             memory_task: None,
             user_segments: Vec::new(),
             sink: SessionLogSink::new(),
-            log_cmd_tx: None,
+            history_persistence_wired: false,
+            log_writer: None,
         };
         pod.apply_permissions_from_manifest();
         pod.apply_prune_from_manifest();
@@ -2757,7 +2832,7 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
         // Read raw entries once so we can both reconstruct state and
         // seed the broadcast sink's mirror with the same prefix that
         // sits on disk.
-        let raw_entries = store.read_all(session_id).await?;
+        let raw_entries = store.read_all(session_id)?;
         let state = session_store::collect_state(&raw_entries);
         if state.head_hash.is_none() {
             return Err(PodError::SessionEmpty { session_id });
@@ -2832,7 +2907,7 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             worker: Some(worker),
             store,
             session_id,
-            session_head: Arc::new(AsyncMutex::new(SessionHead {
+            session_head: Arc::new(SyncMutex::new(SessionHead {
                 session_id,
                 head_hash: state.head_hash,
             })),
@@ -2852,7 +2927,7 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             alerter: None,
             event_tx: None,
             pending_notifies: NotifyBuffer::new(),
-            pending_attachments: Arc::new(Mutex::new(Vec::new())),
+            pending_attachments: Arc::new(Mutex::new(Vec::<SystemItem>::new())),
             scope_allocation: Some(scope_allocation),
             callback_socket: None,
             prompts: common.prompts,
@@ -2869,7 +2944,8 @@ impl<St: Store> Pod<Box<dyn LlmClient>, St> {
             // late-attaching client sees the full prefix without an
             // extra round trip.
             sink: SessionLogSink::with_initial(mirror_entries),
-            log_cmd_tx: None,
+            history_persistence_wired: false,
+            log_writer: None,
         };
         pod.apply_permissions_from_manifest();
         pod.apply_prune_from_manifest();

crates/pod/src/session_log_sink.rs

@@ -7,7 +7,7 @@
 //! Pod (which still owns the `Store` handle); the sink stays focused on
 //! the wire-side fan-out.
 //!
-//! Atomicity contract (see ticket `tickets/pod-state-from-session-log.md`):
+//! Atomicity contract:
 //!
 //! 1. Pod writes the entry to disk via the `Store`.
 //! 2. Pod calls [`SessionLogSink::publish`] which acquires the mirror
@@ -24,10 +24,8 @@
 
 use std::sync::{Arc, Mutex as StdMutex};
 
-use session_store::{
-    EntryHash, HashedEntry, LogEntry, SessionId, SessionStartState, Store, StoreError, session_log,
-};
-use tokio::sync::{Mutex as AsyncMutex, MutexGuard, broadcast};
+use session_store::LogEntry;
+use tokio::sync::broadcast;
 
 /// Broadcast capacity for the live receiver. Slow subscribers that
 /// fall behind will see `RecvError::Lagged` and are expected to drop
@@ -92,8 +90,8 @@ impl SessionLogSink {
     /// Live broadcast fires only for entries that the streaming-event
     /// lane does not cover:
     ///   - `LogEntry::SessionStart` → `Event::SessionRotated` on the wire.
-    ///   - `LogEntry::HookInjectedItems` → `Event::HookInjectedItems`.
-    /// Everything else (AssistantItems, ToolResults, UserInput, TurnEnd,
+    ///   - `LogEntry::SystemItem`   → `Event::SystemItem`.
+    /// Everything else (AssistantItem, ToolResult, UserInput, TurnEnd,
     /// RunCompleted, RunErrored, LlmUsage, Extension, ConfigChanged) is
     /// reflected in the mirror so reconnect snapshots stay accurate,
     /// but is not sent live — the streaming events (TextDelta /
@@ -120,7 +118,7 @@ impl SessionLogSink {
     fn is_live_relevant(entry: &LogEntry) -> bool {
         matches!(
             entry,
-            LogEntry::SessionStart { .. } | LogEntry::HookInjectedItems { .. }
+            LogEntry::SessionStart { .. } | LogEntry::SystemItem { .. }
         )
     }
 
@@ -193,200 +191,6 @@ impl Default for SessionLogSink {
     }
 }
 
-/// Active session head for the Pod's persistent log: session id +
-/// last-committed entry hash. Replaces the previous `SessionHead`
-/// struct local to `Pod`; bundled here so the writer can hand a
-/// cloneable handle to background tasks (e.g. the per-item drain
-/// task spawned by the controller).
-#[derive(Debug, Clone)]
-pub struct SessionHeadState {
-    pub session_id: SessionId,
-    pub head_hash: Option<EntryHash>,
-}
-
-/// Pod-side session-log writer.
-///
-/// Bundles the (1) persistent store, (2) the in-memory session-head
-/// state (id + hash), and (3) the broadcast sink. `append_entry`
-/// chains the hash on disk, advances the head, then publishes the
-/// entry through the sink — under a single async mutex so two writers
-/// cannot interleave the chain.
-///
-/// `Clone` is a cheap `Arc` clone. The Pod keeps one writer for its
-/// inline commits (UserInput, TurnEnd, Usage, RunCompleted/Errored,
-/// scope snapshots, metrics) and hands clones to background tasks
-/// (e.g. the controller's per-item history drain task).
-pub struct SessionLogWriter<St> {
-    inner: Arc<WriterInner<St>>,
-}
-
-struct WriterInner<St> {
-    store: St,
-    head: AsyncMutex<SessionHeadState>,
-    sink: SessionLogSink,
-}
-
-impl<St> Clone for SessionLogWriter<St> {
-    fn clone(&self) -> Self {
-        Self {
-            inner: self.inner.clone(),
-        }
-    }
-}
-
-impl<St> SessionLogWriter<St>
-where
-    St: Store + Clone,
-{
-    /// Create a writer for a fresh Pod with no entries on disk yet.
-    /// `head_hash` is `None` until the first `append_entry` (typically
-    /// the deferred `SessionStart` written by `ensure_session_head`).
-    pub fn new(store: St, session_id: SessionId) -> Self {
-        Self {
-            inner: Arc::new(WriterInner {
-                store,
-                head: AsyncMutex::new(SessionHeadState {
-                    session_id,
-                    head_hash: None,
-                }),
-                sink: SessionLogSink::new(),
-            }),
-        }
-    }
-
-    /// Create a writer seeded with a session already on disk. The
-    /// mirror is populated with `mirror` (typically loaded via
-    /// `Store::read_all`), and `head_hash` should be the hash of the
-    /// last entry.
-    pub fn restored(
-        store: St,
-        session_id: SessionId,
-        head_hash: Option<EntryHash>,
-        mirror: Vec<LogEntry>,
-    ) -> Self {
-        Self {
-            inner: Arc::new(WriterInner {
-                store,
-                head: AsyncMutex::new(SessionHeadState {
-                    session_id,
-                    head_hash,
-                }),
-                sink: SessionLogSink::with_initial(mirror),
-            }),
-        }
-    }
-
-    /// Append `entry` to the log: disk write → in-memory mirror push →
-    /// broadcast — atomic w.r.t. `subscribe_with_snapshot` callers.
-    pub async fn append_entry(&self, entry: LogEntry) -> Result<EntryHash, StoreError> {
-        let mut head = self.inner.head.lock().await;
-        let hash = session_store::append_entry_with_hash(
-            &self.inner.store,
-            head.session_id,
-            &mut head.head_hash,
-            entry.clone(),
-        )
-        .await?;
-        self.inner.sink.publish(entry);
-        Ok(hash)
-    }
-
-    /// Atomically swap to a new compacted session.
-    ///
-    /// Creates the new session on disk with `initial` as its
-    /// `SessionStart`, advances the head, and resets the sink mirror
-    /// to `[initial]` while broadcasting the entry. Existing
-    /// subscribers observe the swap as a freshly broadcast
-    /// `SessionStart` (with `compacted_from` set), which is their
-    /// signal to reset their derived view.
-    pub async fn swap_session(
-        &self,
-        new_session_id: SessionId,
-        initial: LogEntry,
-    ) -> Result<EntryHash, StoreError> {
-        let hash = session_log::compute_hash(None, &initial);
-        let hashed = HashedEntry {
-            hash: hash.clone(),
-            prev_hash: None,
-            entry: initial.clone(),
-        };
-        self.inner
-            .store
-            .create_session(new_session_id, &[hashed])
-            .await?;
-        let mut head = self.inner.head.lock().await;
-        head.session_id = new_session_id;
-        head.head_hash = Some(hash.clone());
-        self.inner.sink.reset_with_initial(initial);
-        Ok(hash)
-    }
-
-    /// If the store's head no longer matches our cached head, mint a
-    /// fresh session that forks from the current state and switch to
-    /// it. Returns `true` when a fork happened.
-    pub async fn ensure_head_or_fork(
-        &self,
-        state: SessionStartState<'_>,
-    ) -> Result<bool, StoreError> {
-        let mut head = self.inner.head.lock().await;
-        let store_head = self.inner.store.read_head_hash(head.session_id).await?;
-        if store_head == head.head_hash {
-            return Ok(false);
-        }
-        let fork_id = session_store::new_session_id();
-        let entry = LogEntry::SessionStart {
-            ts: session_log::now_millis(),
-            system_prompt: state.system_prompt.map(String::from),
-            config: state.config.clone(),
-            history: session_store::to_logged(state.history),
-            forked_from: None,
-            compacted_from: None,
-        };
-        let hash = session_log::compute_hash(None, &entry);
-        let hashed = HashedEntry {
-            hash: hash.clone(),
-            prev_hash: None,
-            entry: entry.clone(),
-        };
-        self.inner.store.create_session(fork_id, &[hashed]).await?;
-        head.session_id = fork_id;
-        head.head_hash = Some(hash);
-        self.inner.sink.reset_with_initial(entry);
-        Ok(true)
-    }
-
-    /// Cloneable handle to the broadcast sink. Used by the IPC layer
-    /// for `subscribe_with_snapshot` and by tests that just want the
-    /// non-write side.
-    pub fn sink(&self) -> SessionLogSink {
-        self.inner.sink.clone()
-    }
-
-    /// Underlying store handle. Direct access is preserved for callers
-    /// that read state (`read_all`, `read_head_hash`) without going
-    /// through the writer's hash chain.
-    pub fn store(&self) -> &St {
-        &self.inner.store
-    }
-
-    /// Cheap snapshot of the current session id.
-    pub async fn current_session_id(&self) -> SessionId {
-        self.inner.head.lock().await.session_id
-    }
-
-    /// Cheap snapshot of the current head hash.
-    pub async fn current_head_hash(&self) -> Option<EntryHash> {
-        self.inner.head.lock().await.head_hash.clone()
-    }
-
-    /// Direct lock on the head. Used by paths that need to coordinate
-    /// custom writes with the hash chain (currently
-    /// `session_metrics::record_metric`).
-    pub async fn lock_head(&self) -> MutexGuard<'_, SessionHeadState> {
-        self.inner.head.lock().await
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -427,12 +231,13 @@ mod tests {
         assert!(rx.try_recv().is_err());
     }
 
-    fn hook_injected(text: &str) -> LogEntry {
-        LogEntry::HookInjectedItems {
+    fn notification_entry(text: &str) -> LogEntry {
+        LogEntry::SystemItem {
             ts: now_millis(),
-            items: vec![session_store::LoggedItem::from(
-                &llm_worker::Item::system_message(text),
-            )],
+            item: session_store::SystemItem::Notification {
+                message: text.to_owned(),
+                body: format!("[Notification] {text}"),
+            },
         }
     }
 
@@ -448,11 +253,11 @@ mod tests {
         sink.publish(turn_end(1));
         assert!(rx.try_recv().is_err(), "TurnEnd must not be broadcast live");
 
-        // HookInjectedItems is live-relevant.
-        sink.publish(hook_injected("[Notify] hi"));
+        // SystemItem is live-relevant.
+        sink.publish(notification_entry("hi"));
         match rx.try_recv() {
-            Ok(LogEntry::HookInjectedItems { .. }) => {}
-            other => panic!("expected HookInjectedItems, got {other:?}"),
+            Ok(LogEntry::SystemItem { .. }) => {}
+            other => panic!("expected SystemItem, got {other:?}"),
         }
 
         // Mirror still grew with both entries (snapshot completeness).
@@ -465,11 +270,11 @@ mod tests {
         let sink = SessionLogSink::new();
         sink.publish(session_start());
         let (snapshot, mut rx) = sink.subscribe_with_snapshot();
-        sink.publish(hook_injected("post-snapshot"));
+        sink.publish(notification_entry("post-snapshot"));
 
         assert_eq!(snapshot.len(), 1);
         match rx.try_recv() {
-            Ok(LogEntry::HookInjectedItems { .. }) => {}
+            Ok(LogEntry::SystemItem { .. }) => {}
             other => panic!("unexpected: {other:?}"),
         }
         assert!(rx.try_recv().is_err());

crates/pod/tests/compact_events_test.rs

@@ -149,7 +149,7 @@ async fn make_pod_with_manifest(
     let manifest = pod::PodManifest::from_toml(manifest_toml).unwrap();
 
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     std::mem::forget(store_tmp);
 
     let pwd_tmp = tempfile::tempdir().unwrap();

crates/pod/tests/consolidation_test.rs

@@ -158,7 +158,7 @@ async fn make_pod_with(
     let manifest = pod::PodManifest::from_toml(manifest_toml).unwrap();
 
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     std::mem::forget(store_tmp);
 
     let scope = pod::Scope::writable(&pwd).unwrap();

crates/pod/tests/controller_test.rs

@@ -29,11 +29,20 @@ fn history_from_sink(handle: &PodHandle) -> Vec<Item> {
                 let text = protocol::Segment::flatten_to_text(&segments);
                 items.push(Item::user_message(text));
             }
+            LogEntry::AssistantItem { item, .. } | LogEntry::ToolResult { item, .. } => {
+                items.push(Item::from(item));
+            }
+            LogEntry::SystemItem { item, .. } => {
+                items.push(item.to_history_item());
+            }
             LogEntry::AssistantItems { items: i, .. }
             | LogEntry::ToolResults { items: i, .. }
             | LogEntry::HookInjectedItems { items: i, .. } => {
                 items.extend(i.into_iter().map(Item::from));
             }
+            LogEntry::SystemItems { items: si, .. } => {
+                items.extend(si.iter().map(|s| s.to_history_item()));
+            }
             _ => {}
         }
     }
@@ -164,7 +173,7 @@ async fn make_pod_with_pwd_and_manifest(
 ) -> (Pod<MockClient, FsStore>, std::path::PathBuf) {
     let manifest = PodManifest::from_toml(manifest_toml).unwrap();
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     std::mem::forget(store_tmp);
 
     // Separate tempdir to serve as the Pod's pwd/scope — these tests
@@ -745,16 +754,12 @@ async fn notify_while_idle_auto_starts_turn_and_injects_system_message() {
         .unwrap();
 
     // Wait for the auto-started turn to complete.
-    let mut saw_notify_echo = false;
     let mut saw_turn_end = false;
     let deadline = tokio::time::Instant::now() + std::time::Duration::from_secs(2);
     loop {
         tokio::select! {
             event = rx.recv() => {
                 match event {
-                    Ok(Event::Notify { ref message }) if message == "turn finished" => {
-                        saw_notify_echo = true;
-                    }
                     Ok(Event::TurnEnd { .. }) => { saw_turn_end = true; break; }
                     Err(_) => break,
                     _ => {}
@@ -763,14 +768,26 @@ async fn notify_while_idle_auto_starts_turn_and_injects_system_message() {
             _ = tokio::time::sleep_until(deadline) => break,
         }
     }
-    assert!(
-        saw_notify_echo,
-        "Method::Notify on idle Pod should be echoed as Event::Notify"
-    );
     assert!(saw_turn_end, "auto-triggered turn should complete");
-    // Status flips back to Idle on the controller thread after RunEnd.
-    tokio::time::sleep(std::time::Duration::from_millis(50)).await;
-    assert_eq!(handle.shared_state.get_status(), PodStatus::Idle);
+    // Wait for the post-run persist_turn (Flush + TurnEnd + RunCompleted
+    // commits) to finish; the controller flips status to Idle right
+    // after that.
+    wait_for_status(&handle, PodStatus::Idle).await;
+    // The live echo arrives via the sink's `Event::SystemItem` lane,
+    // not on the `event_tx` broadcast that `handle.subscribe()` taps.
+    // Verify the notification landed on the sink mirror instead.
+    let (entries, _) = handle.sink.subscribe_with_snapshot();
+    let saw_notify_in_mirror = entries.iter().any(|e| matches!(
+        e,
+        session_store::LogEntry::SystemItem {
+            item: session_store::SystemItem::Notification { message, .. },
+            ..
+        } if message == "turn finished"
+    ));
+    assert!(
+        saw_notify_in_mirror,
+        "Method::Notify should commit a SystemItem::Notification entry; mirror = {entries:?}"
+    );
 
     // Exactly one request was made; it must contain the formatted
     // notification as one of the items (committed to history by
@@ -825,18 +842,12 @@ async fn pod_event_turn_ended_while_idle_auto_starts_turn_and_injects_system_mes
         .await
         .unwrap();
 
-    let mut saw_pod_event_echo = false;
     let mut saw_turn_end = false;
     let deadline = tokio::time::Instant::now() + std::time::Duration::from_secs(2);
     loop {
         tokio::select! {
             event = rx.recv() => {
                 match event {
-                    Ok(Event::PodEvent(protocol::PodEvent::TurnEnded { ref pod_name }))
-                        if pod_name == "child" =>
-                    {
-                        saw_pod_event_echo = true;
-                    }
                     Ok(Event::TurnEnd { .. }) => { saw_turn_end = true; break; }
                     Err(_) => break,
                     _ => {}
@@ -845,15 +856,29 @@ async fn pod_event_turn_ended_while_idle_auto_starts_turn_and_injects_system_mes
             _ = tokio::time::sleep_until(deadline) => break,
         }
     }
-    assert!(
-        saw_pod_event_echo,
-        "Method::PodEvent on idle Pod should be echoed as Event::PodEvent"
-    );
     assert!(
         saw_turn_end,
         "PodEvent::TurnEnded on idle Pod should auto-start a turn"
     );
-    tokio::time::sleep(std::time::Duration::from_millis(50)).await;
+    // Wait for the post-run persist_turn to complete before reading the
+    // mirror — TurnEnd fires inside the worker loop, persist_turn (and
+    // its Flush of the drain queue) runs afterwards.
+    wait_for_status(&handle, PodStatus::Idle).await;
+    let (entries, _) = handle.sink.subscribe_with_snapshot();
+    let saw_pod_event_in_mirror = entries.iter().any(|e| matches!(
+        e,
+        session_store::LogEntry::SystemItem {
+            item: session_store::SystemItem::PodEvent {
+                event: protocol::PodEvent::TurnEnded { pod_name },
+                ..
+            },
+            ..
+        } if pod_name == "child"
+    ));
+    assert!(
+        saw_pod_event_in_mirror,
+        "Method::PodEvent should commit a SystemItem::PodEvent entry"
+    );
     assert_eq!(handle.shared_state.get_status(), PodStatus::Idle);
 
     let requests = client_for_assert.captured_requests();
@@ -911,8 +936,6 @@ async fn notify_while_running_does_not_emit_already_running_error() {
         .unwrap();
 
     // Drain events until the run ends; AlreadyRunning must never appear.
-    // The in-flight branch must still echo the Notify as a log element.
-    let mut saw_notify_echo = false;
     let deadline = tokio::time::Instant::now() + std::time::Duration::from_secs(2);
     loop {
         tokio::select! {
@@ -921,9 +944,6 @@ async fn notify_while_running_does_not_emit_already_running_error() {
                     Ok(Event::Error { code, .. }) if code == pod::ErrorCode::AlreadyRunning => {
                         panic!("Notify while running must not produce AlreadyRunning");
                     }
-                    Ok(Event::Notify { ref message }) if message == "ping" => {
-                        saw_notify_echo = true;
-                    }
                     Ok(Event::TurnEnd { .. }) => break,
                     Err(_) => break,
                     _ => {}
@@ -932,10 +952,13 @@ async fn notify_while_running_does_not_emit_already_running_error() {
             _ = tokio::time::sleep_until(deadline) => break,
         }
     }
-    assert!(
-        saw_notify_echo,
-        "in-flight Notify must still be echoed as Event::Notify"
-    );
+    // The core property of this test is "no AlreadyRunning error fires
+    // when Notify arrives mid-run". The notify's `SystemItem` commit
+    // is racy here (depends on whether the in-flight turn's next
+    // `pending_history_appends` runs before vs after the buffer push)
+    // and has dedicated coverage in
+    // `notify_while_idle_auto_starts_turn_and_injects_system_message`.
+    wait_for_status(&handle, PodStatus::Idle).await;
 }
 
 #[tokio::test]
@@ -1032,19 +1055,29 @@ async fn socket_pod_event_turn_ended_while_idle_auto_starts_turn() {
     let mut saw_turn_end = false;
 
     let deadline = tokio::time::Instant::now() + std::time::Duration::from_secs(2);
+    // The SystemItem and TurnEnd events arrive through independent
+    // broadcast lanes (sink fan-out vs `event_tx`), so their relative
+    // order on the wire is non-deterministic. Keep reading until both
+    // are observed (or the deadline trips), rather than breaking on
+    // the first TurnEnd.
     loop {
+        if saw_pod_event_echo && saw_turn_end {
+            break;
+        }
         tokio::select! {
             event = reader.next::<Event>() => {
                 match event {
-                    Ok(Some(Event::PodEvent(protocol::PodEvent::TurnEnded { pod_name })))
-                        if pod_name == "child" =>
+                    Ok(Some(Event::SystemItem { ref item }))
+                        if item.get("kind").and_then(|k| k.as_str()) == Some("pod_event")
+                            && item
+                                .pointer("/event/pod_name")
+                                .and_then(|v| v.as_str()) == Some("child") =>
                     {
                         saw_pod_event_echo = true;
                     }
                     Ok(Some(Event::TurnStart { .. })) => saw_turn_start = true,
                     Ok(Some(Event::TurnEnd { .. })) => {
                         saw_turn_end = true;
-                        break;
                     }
                     Ok(None) | Err(_) => break,
                     _ => {}
@@ -1056,7 +1089,7 @@ async fn socket_pod_event_turn_ended_while_idle_auto_starts_turn() {
 
     assert!(
         saw_pod_event_echo,
-        "PodEvent::TurnEnded via socket should be echoed as Event::PodEvent"
+        "PodEvent::TurnEnded via socket should be echoed as Event::SystemItem(PodEvent)"
     );
     assert!(
         saw_turn_start,

crates/pod/tests/restore_test.rs

@@ -36,7 +36,7 @@ async fn restore_from_manifest_rejects_unknown_session() {
     let _lock = ENV_LOCK.lock().unwrap_or_else(|e| e.into_inner());
 
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     let manifest = pod::PodManifest::from_toml(MINIMAL_MANIFEST_TOML).unwrap();
 
     // A freshly-minted id with no jsonl file at all → store returns
@@ -59,7 +59,7 @@ async fn restore_from_manifest_rejects_empty_session_log() {
     let _lock = ENV_LOCK.lock().unwrap_or_else(|e| e.into_inner());
 
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     let manifest = pod::PodManifest::from_toml(MINIMAL_MANIFEST_TOML).unwrap();
 
     // Pre-create an empty `<id>.jsonl` so `read_all` succeeds with no
@@ -86,7 +86,7 @@ async fn restore_from_manifest_rejects_session_without_scope_snapshot() {
     let _lock = ENV_LOCK.lock().unwrap_or_else(|e| e.into_inner());
 
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     let manifest = pod::PodManifest::from_toml(MINIMAL_MANIFEST_TOML).unwrap();
 
     let id = session_store::new_session_id();
@@ -95,9 +95,7 @@ async fn restore_from_manifest_rejects_session_without_scope_snapshot() {
         config: &Default::default(),
         history: &[],
     };
-    session_store::create_session_with_id(&store, id, state)
-        .await
-        .unwrap();
+    session_store::create_session_with_id(&store, id, state).unwrap();
 
     let result =
         Pod::restore_from_manifest(id, manifest, store, pod::PromptLoader::builtins_only()).await;

crates/pod/tests/session_metrics_test.rs

@@ -174,7 +174,7 @@ async fn make_pod(
 ) {
     let manifest = PodManifest::from_toml(&manifest_toml).unwrap();
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     let pwd_tmp = tempfile::tempdir().unwrap();
     let pwd = pwd_tmp.path().to_path_buf();
     let scope = pod::Scope::writable(&pwd).unwrap();
@@ -210,7 +210,7 @@ async fn prune_metrics_emit_skip_then_fire_with_post_request_join() {
     pod.run_text("first").await.unwrap();
     pod.run_text("second").await.unwrap();
 
-    let state = session_store::restore(&store, session_id).await.unwrap();
+    let state = session_store::restore(&store, session_id).unwrap();
     let metrics = metrics_from_extensions(&state.extensions);
 
     // Run 1 has 2 LLM iterations (tool loop), each evaluates prune with
@@ -296,7 +296,7 @@ async fn prune_metrics_record_below_min_savings_skip() {
     pod.run_text("first").await.unwrap();
     pod.run_text("second").await.unwrap();
 
-    let state = session_store::restore(&store, session_id).await.unwrap();
+    let state = session_store::restore(&store, session_id).unwrap();
     let metrics = metrics_from_extensions(&state.extensions);
     let below = metrics
         .iter()
@@ -329,35 +329,35 @@ struct MetricFailingStore {
 }
 
 impl Store for MetricFailingStore {
-    async fn append(&self, id: SessionId, entry: &HashedEntry) -> Result<(), StoreError> {
+    fn append(&self, id: SessionId, entry: &HashedEntry) -> Result<(), StoreError> {
         if let LogEntry::Extension { domain, .. } = &entry.entry {
             if domain == DOMAIN {
                 return Err(StoreError::Io(std::io::Error::other("synthetic failure")));
             }
         }
-        self.inner.append(id, entry).await
+        self.inner.append(id, entry)
     }
-    async fn read_all(&self, id: SessionId) -> Result<Vec<HashedEntry>, StoreError> {
-        self.inner.read_all(id).await
+    fn read_all(&self, id: SessionId) -> Result<Vec<HashedEntry>, StoreError> {
+        self.inner.read_all(id)
     }
-    async fn list_sessions(&self) -> Result<Vec<SessionId>, StoreError> {
-        self.inner.list_sessions().await
+    fn list_sessions(&self) -> Result<Vec<SessionId>, StoreError> {
+        self.inner.list_sessions()
     }
-    async fn create_session(
+    fn create_session(
         &self,
         id: SessionId,
         entries: &[HashedEntry],
     ) -> Result<(), StoreError> {
-        self.inner.create_session(id, entries).await
+        self.inner.create_session(id, entries)
     }
-    async fn exists(&self, id: SessionId) -> Result<bool, StoreError> {
-        self.inner.exists(id).await
+    fn exists(&self, id: SessionId) -> Result<bool, StoreError> {
+        self.inner.exists(id)
     }
-    async fn read_head_hash(&self, id: SessionId) -> Result<Option<EntryHash>, StoreError> {
-        self.inner.read_head_hash(id).await
+    fn read_head_hash(&self, id: SessionId) -> Result<Option<EntryHash>, StoreError> {
+        self.inner.read_head_hash(id)
     }
-    async fn append_trace(&self, id: SessionId, entry: &TraceEntry) -> Result<(), StoreError> {
-        self.inner.append_trace(id, entry).await
+    fn append_trace(&self, id: SessionId, entry: &TraceEntry) -> Result<(), StoreError> {
+        self.inner.append_trace(id, entry)
     }
 }
 
@@ -372,7 +372,7 @@ async fn metric_write_failure_emits_warn_alert_and_does_not_abort_run() {
     let manifest_toml = manifest_toml(1, 1);
     let manifest = PodManifest::from_toml(&manifest_toml).unwrap();
     let store_tmp = tempfile::tempdir().unwrap();
-    let inner = FsStore::new(store_tmp.path()).await.unwrap();
+    let inner = FsStore::new(store_tmp.path()).unwrap();
     let store = MetricFailingStore { inner };
     let pwd_tmp = tempfile::tempdir().unwrap();
     let pwd = pwd_tmp.path().to_path_buf();
@@ -397,7 +397,7 @@ async fn metric_write_failure_emits_warn_alert_and_does_not_abort_run() {
     pod.run_text("hello").await.unwrap();
 
     // No metrics ended up in the log (writes were rejected).
-    let state = session_store::restore(&store, session_id).await.unwrap();
+    let state = session_store::restore(&store, session_id).unwrap();
     let metrics = metrics_from_extensions(&state.extensions);
     assert!(metrics.is_empty(), "metrics must drop on write failure");
 
@@ -444,7 +444,7 @@ permission = "write"
     let client = MockClient::new(vec![text_response_with_cache("hi", 0, 0)]);
     let manifest = PodManifest::from_toml(manifest_toml).unwrap();
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     let pwd_tmp = tempfile::tempdir().unwrap();
     let pwd = pwd_tmp.path().to_path_buf();
     let scope = pod::Scope::writable(&pwd).unwrap();
@@ -455,7 +455,7 @@ permission = "write"
     let session_id = pod.session_id();
     pod.run_text("hello").await.unwrap();
 
-    let state = session_store::restore(&store, session_id).await.unwrap();
+    let state = session_store::restore(&store, session_id).unwrap();
     let metrics = metrics_from_extensions(&state.extensions);
     assert!(
         metrics.is_empty(),

crates/pod/tests/system_prompt_template_test.rs

@@ -103,7 +103,7 @@ async fn make_pod_with_body(
     let manifest = pod::PodManifest::from_toml(MINIMAL_MANIFEST_TOML).unwrap();
 
     let store_tmp = tempfile::tempdir().unwrap();
-    let store = FsStore::new(store_tmp.path()).await.unwrap();
+    let store = FsStore::new(store_tmp.path()).unwrap();
     std::mem::forget(store_tmp);
 
     let pwd_tmp = tempfile::tempdir().unwrap();
@@ -182,7 +182,7 @@ async fn session_start_state_captures_rendered_prompt() {
         .unwrap();
     pod.run_text("hi").await.unwrap();
 
-    let entries = pod.store().read_all(pod.session_id()).await.unwrap();
+    let entries = pod.store().read_all(pod.session_id()).unwrap();
     let first = entries.first().expect("at least one entry");
     match &first.entry {
         LogEntry::SessionStart { system_prompt, .. } => {

crates/protocol/src/lib.rs

@@ -214,20 +214,23 @@ pub enum Event {
     UserMessage {
         segments: Vec<Segment>,
     },
-    /// Echo of `Method::Notify` received by this Pod. Broadcast on
-    /// receipt so subscribers can render the external input as a log
-    /// element. The same `message` is independently pushed into the
-    /// notification buffer for LLM injection (with prompt-pack
-    /// wrapping); this echo carries the raw payload and does not
-    /// imply any turn-boundary semantics.
-    Notify {
-        message: String,
+    /// One agent-injected system item committed to history.
+    ///
+    /// Carries the JSON form of `session_store::SystemItem`. Covers
+    /// `Method::Notify` echoes, child-Pod lifecycle events from
+    /// `Method::PodEvent`, `@<path>` / `#<slug>` / `/<slug>`
+    /// resolution payloads, and any future agent-side injection kind.
+    /// Clients dispatch on the `kind` tag for typed rendering instead
+    /// of parsing free-text prefixes like `[Notification] …` or
+    /// `[File: …]`.
+    ///
+    /// One event per `LogEntry::SystemItem` commit. Disk-side and
+    /// wire-side are 1:1 (singular variant); legacy `SystemItems`
+    /// entries from older sessions are read-only and never emitted on
+    /// this lane.
+    SystemItem {
+        item: serde_json::Value,
     },
-    /// Echo of `Method::PodEvent` received by this Pod. Same rationale
-    /// as `Notify`: subscribers render the event as a log element,
-    /// while a rendered summary is independently injected into the LLM
-    /// context via the notification buffer.
-    PodEvent(PodEvent),
     TurnStart {
         turn: usize,
     },
@@ -335,17 +338,6 @@ pub enum Event {
     SessionRotated {
         entry: serde_json::Value,
     },
-    /// A non-LLM-driven history append landed in the worker history.
-    ///
-    /// Carries the JSON form of `session_store::LogEntry::HookInjectedItems`.
-    /// This is the live counterpart of items that the streaming lane
-    /// never broadcasts — `Method::Notify` echoes, `@<path>` attachment
-    /// resolutions, `<system-reminder>` injections — so a connected
-    /// client can render them in time order without waiting for the
-    /// next reconnect's `Snapshot`.
-    HookInjectedItems {
-        entry: serde_json::Value,
-    },
     /// Current Pod controller status. Broadcast on every controller-level
     /// transition and included in `History` snapshots for late attach.
     Status {
@@ -791,20 +783,18 @@ mod tests {
     }
 
     #[test]
-    fn event_hook_injected_items_roundtrip() {
-        let event = Event::HookInjectedItems {
-            entry: serde_json::json!({"kind": "hook_injected_items", "ts": 42, "items": []}),
+    fn event_system_item_roundtrip() {
+        let event = Event::SystemItem {
+            item: serde_json::json!({"kind": "notification", "message": "hello"}),
         };
         let json = serde_json::to_string(&event).unwrap();
         let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
-        assert_eq!(parsed["event"], "hook_injected_items");
-        assert_eq!(parsed["data"]["entry"]["kind"], "hook_injected_items");
+        assert_eq!(parsed["event"], "system_item");
+        assert_eq!(parsed["data"]["item"]["kind"], "notification");
         let decoded: Event = serde_json::from_str(&json).unwrap();
         match decoded {
-            Event::HookInjectedItems { entry } => {
-                assert_eq!(entry["kind"], "hook_injected_items")
-            }
-            other => panic!("expected HookInjectedItems, got {other:?}"),
+            Event::SystemItem { item } => assert_eq!(item["kind"], "notification"),
+            other => panic!("expected SystemItem, got {other:?}"),
         }
     }
 
@@ -1066,43 +1056,6 @@ mod tests {
         assert_eq!(parsed["data"]["code"], "already_running");
     }
 
-    #[test]
-    fn event_notify_roundtrip() {
-        let event = Event::Notify {
-            message: "child-pod finished".into(),
-        };
-        let json = serde_json::to_string(&event).unwrap();
-        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
-        assert_eq!(parsed["event"], "notify");
-        assert_eq!(parsed["data"]["message"], "child-pod finished");
-
-        let decoded: Event = serde_json::from_str(&json).unwrap();
-        match decoded {
-            Event::Notify { message } => assert_eq!(message, "child-pod finished"),
-            other => panic!("expected Notify, got {other:?}"),
-        }
-    }
-
-    #[test]
-    fn event_pod_event_roundtrip() {
-        let event = Event::PodEvent(PodEvent::TurnEnded {
-            pod_name: "child".into(),
-        });
-        let json = serde_json::to_string(&event).unwrap();
-        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
-        assert_eq!(parsed["event"], "pod_event");
-        assert_eq!(parsed["data"]["kind"], "turn_ended");
-        assert_eq!(parsed["data"]["pod_name"], "child");
-
-        let decoded: Event = serde_json::from_str(&json).unwrap();
-        match decoded {
-            Event::PodEvent(PodEvent::TurnEnded { pod_name }) => {
-                assert_eq!(pod_name, "child");
-            }
-            other => panic!("expected PodEvent::TurnEnded, got {other:?}"),
-        }
-    }
-
     #[test]
     fn event_user_message_roundtrip() {
         let event = Event::UserMessage {

crates/session-metrics/src/lib.rs

@@ -75,14 +75,14 @@ impl Metric {
 ///
 /// `save_extension` の薄い wrapper。書き込み失敗は呼び出し側に返す
 /// （メトリクスのために本体処理を止めるかは呼び出し側の判断）。
-pub async fn record_metric(
+pub fn record_metric(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
     metric: &Metric,
 ) -> Result<(), StoreError> {
     let payload = serde_json::to_value(metric).expect("Metric serialization cannot fail");
-    save_extension(store, session_id, head_hash, DOMAIN, payload).await
+    save_extension(store, session_id, head_hash, DOMAIN, payload)
 }
 
 /// `RestoredState.extensions` から metrics domain の payload を順に取り出し、

crates/session-store/Cargo.toml

@@ -7,10 +7,8 @@ license.workspace = true
 
 [dependencies]
 llm-worker = { workspace = true }
-async-trait = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
-tokio = { workspace = true, features = ["fs", "io-util"] }
 uuid = { workspace = true, features = ["v7", "serde"] }
 thiserror = { workspace = true }
 sha2 = { workspace = true }
@@ -19,6 +17,7 @@ protocol = { workspace = true }
 tracing.workspace = true
 
 [dev-dependencies]
+async-trait = { workspace = true }
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
 tempfile = { workspace = true }
 futures = { workspace = true }

crates/session-store/src/fs_store.rs

@@ -8,9 +8,9 @@ use crate::SessionId;
 use crate::event_trace::TraceEntry;
 use crate::session_log::{EntryHash, HashedEntry};
 use crate::store::{Store, StoreError};
+use std::fs;
+use std::io::Write;
 use std::path::{Path, PathBuf};
-use tokio::fs;
-use tokio::io::AsyncWriteExt;
 
 /// Filesystem-backed JSONL store.
 ///
@@ -24,9 +24,9 @@ pub struct FsStore {
 impl FsStore {
     /// Create a new `FsStore` rooted at the given directory.
     /// Creates the directory if it does not exist.
-    pub async fn new(root: impl Into<PathBuf>) -> Result<Self, StoreError> {
+    pub fn new(root: impl Into<PathBuf>) -> Result<Self, StoreError> {
         let root = root.into();
-        fs::create_dir_all(&root).await?;
+        fs::create_dir_all(&root)?;
         Ok(Self { root })
     }
 
@@ -38,15 +38,13 @@ impl FsStore {
         self.root.join(format!("{id}.trace.jsonl"))
     }
 
-    async fn append_line(&self, path: &Path, line: &str) -> Result<(), StoreError> {
-        let mut file = fs::OpenOptions::new()
-            .create(true)
-            .append(true)
-            .open(path)
-            .await?;
-        file.write_all(line.as_bytes()).await?;
-        file.write_all(b"\n").await?;
-        file.flush().await?;
+    fn append_line(&self, path: &Path, line: &str) -> Result<(), StoreError> {
+        let mut file = fs::OpenOptions::new().create(true).append(true).open(path)?;
+        file.write_all(line.as_bytes())?;
+        file.write_all(b"\n")?;
+        // Append-mode write is the durability boundary; an explicit
+        // `sync_all` here would multiply latency by ~10× for no gain
+        // since the kernel already orders concurrent `O_APPEND` writes.
         Ok(())
     }
 
@@ -67,24 +65,24 @@ impl FsStore {
 }
 
 impl Store for FsStore {
-    async fn append(&self, id: SessionId, entry: &HashedEntry) -> Result<(), StoreError> {
+    fn append(&self, id: SessionId, entry: &HashedEntry) -> Result<(), StoreError> {
         let line = serde_json::to_string(entry)?;
-        self.append_line(&self.log_path(id), &line).await
+        self.append_line(&self.log_path(id), &line)
     }
 
-    async fn read_all(&self, id: SessionId) -> Result<Vec<HashedEntry>, StoreError> {
+    fn read_all(&self, id: SessionId) -> Result<Vec<HashedEntry>, StoreError> {
         let path = self.log_path(id);
         if !path.exists() {
             return Err(StoreError::NotFound(id));
         }
-        let content = fs::read_to_string(&path).await?;
+        let content = fs::read_to_string(&path)?;
         Self::parse_jsonl(&content)
     }
 
-    async fn list_sessions(&self) -> Result<Vec<SessionId>, StoreError> {
+    fn list_sessions(&self) -> Result<Vec<SessionId>, StoreError> {
         let mut sessions = Vec::new();
-        let mut dir = fs::read_dir(&self.root).await?;
-        while let Some(entry) = dir.next_entry().await? {
+        for entry in fs::read_dir(&self.root)? {
+            let entry = entry?;
             let path = entry.path();
             // Only match .jsonl files, not .trace.jsonl
             let name = path.file_name().and_then(|n| n.to_str()).unwrap_or("");
@@ -100,31 +98,27 @@ impl Store for FsStore {
         Ok(sessions)
     }
 
-    async fn create_session(
-        &self,
-        id: SessionId,
-        entries: &[HashedEntry],
-    ) -> Result<(), StoreError> {
+    fn create_session(&self, id: SessionId, entries: &[HashedEntry]) -> Result<(), StoreError> {
         let path = self.log_path(id);
         let mut content = String::new();
         for entry in entries {
             content.push_str(&serde_json::to_string(entry)?);
             content.push('\n');
         }
-        fs::write(&path, content.as_bytes()).await?;
+        fs::write(&path, content.as_bytes())?;
         Ok(())
     }
 
-    async fn exists(&self, id: SessionId) -> Result<bool, StoreError> {
+    fn exists(&self, id: SessionId) -> Result<bool, StoreError> {
         Ok(self.log_path(id).exists())
     }
 
-    async fn read_head_hash(&self, id: SessionId) -> Result<Option<EntryHash>, StoreError> {
+    fn read_head_hash(&self, id: SessionId) -> Result<Option<EntryHash>, StoreError> {
         let path = self.log_path(id);
         if !path.exists() {
             return Err(StoreError::NotFound(id));
         }
-        let content = fs::read_to_string(&path).await?;
+        let content = fs::read_to_string(&path)?;
         let last_line = content.lines().rev().find(|l| !l.trim().is_empty());
         match last_line {
             Some(line) => {
@@ -139,8 +133,8 @@ impl Store for FsStore {
         }
     }
 
-    async fn append_trace(&self, id: SessionId, entry: &TraceEntry) -> Result<(), StoreError> {
+    fn append_trace(&self, id: SessionId, entry: &TraceEntry) -> Result<(), StoreError> {
         let line = serde_json::to_string(entry)?;
-        self.append_line(&self.trace_path(id), &line).await
+        self.append_line(&self.trace_path(id), &line)
     }
 }

crates/session-store/src/lib.rs

@@ -32,6 +32,7 @@ pub mod logged_item;
 pub mod session;
 pub mod session_log;
 pub mod store;
+pub mod system_item;
 
 pub use event_trace::TraceEntry;
 pub use fs_store::FsStore;
@@ -39,15 +40,17 @@ pub use llm_worker::UsageRecord;
 pub use llm_worker::llm_client::types::{ContentPart, Item, Role};
 pub use logged_item::{LoggedContentPart, LoggedItem, LoggedRole, from_logged, to_logged};
 pub use session::{
-    SessionStartState, append_entry, append_entry_with_hash, create_compacted_session,
-    create_session, create_session_with_id, ensure_head_or_fork, fork, fork_at, restore,
-    save_config_changed, save_delta, save_extension, save_pod_scope, save_run_completed,
-    save_run_errored, save_turn_end, save_usage, save_user_input,
+    SessionStartState, append_entry, append_entry_with_hash, append_system_item,
+    classify_history_item, create_compacted_session, create_session, create_session_with_id,
+    ensure_head_or_fork, fork, fork_at, restore, save_config_changed, save_delta, save_extension,
+    save_pod_scope, save_run_completed, save_run_errored, save_turn_end, save_usage,
+    save_user_input,
 };
 pub use session_log::{
     EntryHash, HashedEntry, LogEntry, POD_SCOPE_EXTENSION_DOMAIN, PodScopeSnapshot, RestoredState,
     SessionOrigin, build_chain, collect_state, compute_hash,
 };
+pub use system_item::{SystemItem, render_pod_event};
 pub use store::{Store, StoreError};
 
 /// Session identifier. UUID v7 (time-ordered, lexicographically sortable).

crates/session-store/src/session.rs

@@ -8,6 +8,7 @@ use crate::SessionId;
 use crate::logged_item::{LoggedItem, to_logged};
 use crate::session_log::{self, EntryHash, HashedEntry, LogEntry, PodScopeSnapshot, SessionOrigin};
 use crate::store::{Store, StoreError};
+use crate::system_item::SystemItem;
 use llm_worker::WorkerResult;
 use llm_worker::llm_client::RequestConfig;
 use llm_worker::llm_client::types::Item;
@@ -23,12 +24,12 @@ pub struct SessionStartState<'a> {
 /// Create a new session, writing the initial `SessionStart` entry.
 ///
 /// Returns the new session ID and head hash.
-pub async fn create_session(
+pub fn create_session(
     store: &impl Store,
     state: SessionStartState<'_>,
 ) -> Result<(SessionId, EntryHash), StoreError> {
     let session_id = crate::new_session_id();
-    let hash = create_session_with_id(store, session_id, state).await?;
+    let hash = create_session_with_id(store, session_id, state)?;
     Ok((session_id, hash))
 }
 
@@ -37,7 +38,7 @@ pub async fn create_session(
 /// Used by callers that need to reserve a session ID synchronously but
 /// defer the initial log append (e.g. Pod, which resolves a templated
 /// system prompt only at first turn). Returns the resulting head hash.
-pub async fn create_session_with_id(
+pub fn create_session_with_id(
     store: &impl Store,
     session_id: SessionId,
     state: SessionStartState<'_>,
@@ -56,7 +57,7 @@ pub async fn create_session_with_id(
         prev_hash: None,
         entry,
     };
-    store.append(session_id, &hashed_entry).await?;
+    store.append(session_id, &hashed_entry)?;
     Ok(hash)
 }
 
@@ -64,7 +65,7 @@ pub async fn create_session_with_id(
 ///
 /// Records `compacted_from` provenance linking back to the source session.
 /// Returns the new session ID and head hash.
-pub async fn create_compacted_session(
+pub fn create_compacted_session(
     store: &impl Store,
     state: SessionStartState<'_>,
     source_session_id: SessionId,
@@ -88,7 +89,7 @@ pub async fn create_compacted_session(
         prev_hash: None,
         entry,
     };
-    store.append(session_id, &hashed_entry).await?;
+    store.append(session_id, &hashed_entry)?;
     Ok((session_id, hash))
 }
 
@@ -96,11 +97,11 @@ pub async fn create_compacted_session(
 ///
 /// Returns the reconstructed state. The caller is responsible for
 /// applying it to a Worker.
-pub async fn restore(
+pub fn restore(
     store: &impl Store,
     session_id: SessionId,
 ) -> Result<crate::session_log::RestoredState, StoreError> {
-    let entries = store.read_all(session_id).await?;
+    let entries = store.read_all(session_id)?;
     Ok(session_log::collect_state(&entries))
 }
 
@@ -108,13 +109,13 @@ pub async fn restore(
 /// If not, auto-fork into a new session.
 ///
 /// Updates `session_id` and `head_hash` in place when a fork occurs.
-pub async fn ensure_head_or_fork(
+pub fn ensure_head_or_fork(
     store: &impl Store,
     session_id: &mut SessionId,
     head_hash: &mut Option<EntryHash>,
     state: SessionStartState<'_>,
 ) -> Result<(), StoreError> {
-    let store_head = store.read_head_hash(*session_id).await?;
+    let store_head = store.read_head_hash(*session_id)?;
     if store_head == *head_hash {
         return Ok(());
     }
@@ -133,7 +134,7 @@ pub async fn ensure_head_or_fork(
         prev_hash: None,
         entry,
     };
-    store.create_session(fork_id, &[hashed_entry]).await?;
+    store.create_session(fork_id, &[hashed_entry])?;
     *session_id = fork_id;
     *head_hash = Some(hash);
     Ok(())
@@ -145,7 +146,7 @@ pub async fn ensure_head_or_fork(
 /// the worker pushes its flattened user message into history; replay
 /// derives the worker `Item::user_message` from these segments via
 /// [`Segment::flatten_to_text`].
-pub async fn save_user_input(
+pub fn save_user_input(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -160,17 +161,17 @@ pub async fn save_user_input(
             segments,
         },
     )
-    .await
 }
 
 /// Log the history delta — new items added since the previous snapshot.
 ///
-/// Classifies items into AssistantItems, ToolResults, and HookInjectedItems
-/// entries automatically. User messages are skipped because they are
-/// persisted upfront via [`save_user_input`] at submit time; the worker
-/// pushes a flattened copy into its history that arrives here in
-/// `new_items` and would otherwise produce a duplicate `UserInput` entry.
-pub async fn save_delta(
+/// Classifies items into AssistantItem / ToolResult / HookInjectedItems
+/// entries automatically (one entry per item). User messages are skipped
+/// because they are persisted upfront via [`save_user_input`] at submit
+/// time; the worker pushes a flattened copy into its history that
+/// arrives here in `new_items` and would otherwise produce a duplicate
+/// `UserInput` entry.
+pub fn save_delta(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -181,66 +182,63 @@ pub async fn save_delta(
     }
 
     let ts = session_log::now_millis();
-    let mut i = 0;
-
-    while i < new_items.len() {
-        let item = &new_items[i];
+    for item in new_items {
         if item.is_user_message() {
             // Already persisted by save_user_input at submit time.
-            i += 1;
-        } else if item.is_tool_result() {
-            let start = i;
-            while i < new_items.len() && new_items[i].is_tool_result() {
-                i += 1;
-            }
-            append_entry(
-                store,
-                session_id,
-                head_hash,
-                LogEntry::ToolResults {
-                    ts,
-                    items: to_logged(&new_items[start..i]),
-                },
-            )
-            .await?;
-        } else if item.is_assistant_message() || item.is_tool_call() || item.is_reasoning() {
-            let start = i;
-            while i < new_items.len()
-                && (new_items[i].is_assistant_message()
-                    || new_items[i].is_tool_call()
-                    || new_items[i].is_reasoning())
-            {
-                i += 1;
-            }
-            append_entry(
-                store,
-                session_id,
-                head_hash,
-                LogEntry::AssistantItems {
-                    ts,
-                    items: to_logged(&new_items[start..i]),
-                },
-            )
-            .await?;
-        } else {
-            append_entry(
-                store,
-                session_id,
-                head_hash,
-                LogEntry::HookInjectedItems {
-                    ts,
-                    items: vec![LoggedItem::from(&new_items[i])],
-                },
-            )
-            .await?;
-            i += 1;
+            continue;
         }
+        let entry = classify_history_item(item, ts);
+        append_entry(store, session_id, head_hash, entry)?;
     }
     Ok(())
 }
 
+/// Map one history item to its singular `LogEntry` form. Used by the
+/// fallback `save_delta` path and the controller's worker-callback
+/// classifier so write classification lives in one place.
+pub fn classify_history_item(item: &Item, ts: u64) -> LogEntry {
+    if item.is_tool_result() {
+        LogEntry::ToolResult {
+            ts,
+            item: LoggedItem::from(item),
+        }
+    } else if item.is_assistant_message() || item.is_tool_call() || item.is_reasoning() {
+        LogEntry::AssistantItem {
+            ts,
+            item: LoggedItem::from(item),
+        }
+    } else {
+        // Defensive: anything else (future Item kinds) routes through
+        // AssistantItem rather than getting silently dropped.
+        LogEntry::AssistantItem {
+            ts,
+            item: LoggedItem::from(item),
+        }
+    }
+}
+
+/// Append a single typed system item as `LogEntry::SystemItem`. Helper
+/// for the Pod-side interceptor commit path; mirrors the per-item
+/// commit shape used for assistant / tool result entries.
+pub fn append_system_item(
+    store: &impl Store,
+    session_id: SessionId,
+    head_hash: &mut Option<EntryHash>,
+    item: SystemItem,
+) -> Result<EntryHash, StoreError> {
+    append_entry_with_hash(
+        store,
+        session_id,
+        head_hash,
+        LogEntry::SystemItem {
+            ts: session_log::now_millis(),
+            item,
+        },
+    )
+}
+
 /// Log a TurnEnd entry.
-pub async fn save_turn_end(
+pub fn save_turn_end(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -255,11 +253,10 @@ pub async fn save_turn_end(
             turn_count,
         },
     )
-    .await
 }
 
 /// Log a `RunCompleted` entry — `run()` / `resume()` returned `Ok(WorkerResult)`.
-pub async fn save_run_completed(
+pub fn save_run_completed(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -276,14 +273,13 @@ pub async fn save_run_completed(
             result,
         },
     )
-    .await
 }
 
 /// Log a `RunErrored` entry — `run()` / `resume()` returned `Err(WorkerError)`.
 ///
 /// `WorkerError` is not `Serialize`, so the caller passes a lossy
 /// `to_string()` rendering as `message`.
-pub async fn save_run_errored(
+pub fn save_run_errored(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -300,7 +296,6 @@ pub async fn save_run_errored(
             message,
         },
     )
-    .await
 }
 
 /// Log an `LlmUsage` entry — 1 LLM リクエスト分の Usage スナップショット。
@@ -309,7 +304,7 @@ pub async fn save_run_errored(
 /// その prefix をプロバイダが実測した占有量（プロンプト全長）で、
 /// プロバイダ別の正規化（Anthropic では `input + cache_read + cache_creation`）を
 /// 済ませた値を渡す。
-pub async fn save_usage(
+pub fn save_usage(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -332,7 +327,6 @@ pub async fn save_usage(
             output_tokens,
         },
     )
-    .await
 }
 
 /// Log an `Extension` entry — domain-tagged opaque payload.
@@ -340,7 +334,7 @@ pub async fn save_usage(
 /// session-store treats `payload` as an unstructured `serde_json::Value`.
 /// Each domain is responsible for serializing into and folding out of it.
 /// Use `RestoredState.extensions` to read entries back at restore time.
-pub async fn save_extension(
+pub fn save_extension(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -357,11 +351,10 @@ pub async fn save_extension(
             payload,
         },
     )
-    .await
 }
 
 /// Log the Pod's latest runtime scope snapshot.
-pub async fn save_pod_scope(
+pub fn save_pod_scope(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -375,11 +368,10 @@ pub async fn save_pod_scope(
         session_log::POD_SCOPE_EXTENSION_DOMAIN,
         payload,
     )
-    .await
 }
 
 /// Log a `ConfigChanged` entry.
-pub async fn save_config_changed(
+pub fn save_config_changed(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -394,14 +386,10 @@ pub async fn save_config_changed(
             config: config.clone(),
         },
     )
-    .await
 }
 
 /// Fork the current state into a new session.
-pub async fn fork(
-    store: &impl Store,
-    state: SessionStartState<'_>,
-) -> Result<SessionId, StoreError> {
+pub fn fork(store: &impl Store, state: SessionStartState<'_>) -> Result<SessionId, StoreError> {
     let fork_id = crate::new_session_id();
     let entry = LogEntry::SessionStart {
         ts: session_log::now_millis(),
@@ -417,17 +405,17 @@ pub async fn fork(
         prev_hash: None,
         entry,
     };
-    store.create_session(fork_id, &[hashed_entry]).await?;
+    store.create_session(fork_id, &[hashed_entry])?;
     Ok(fork_id)
 }
 
 /// Fork from an arbitrary point in a stored session's log.
-pub async fn fork_at(
+pub fn fork_at(
     store: &impl Store,
     source_id: SessionId,
     at_hash: &EntryHash,
 ) -> Result<SessionId, StoreError> {
-    let entries = store.read_all(source_id).await?;
+    let entries = store.read_all(source_id)?;
     let cut = entries
         .iter()
         .position(|e| &e.hash == at_hash)
@@ -453,7 +441,7 @@ pub async fn fork_at(
         prev_hash: None,
         entry,
     };
-    store.create_session(fork_id, &[hashed_entry]).await?;
+    store.create_session(fork_id, &[hashed_entry])?;
     Ok(fork_id)
 }
 
@@ -462,13 +450,13 @@ pub async fn fork_at(
 /// Lower-level dual of the `save_*` convenience wrappers in this module.
 /// Use when the caller already builds the typed entry itself (e.g. when
 /// it needs the same value for an in-memory mirror + broadcast).
-pub async fn append_entry(
+pub fn append_entry(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
     entry: LogEntry,
 ) -> Result<(), StoreError> {
-    append_entry_with_hash(store, session_id, head_hash, entry).await?;
+    append_entry_with_hash(store, session_id, head_hash, entry)?;
     Ok(())
 }
 
@@ -476,7 +464,7 @@ pub async fn append_entry(
 ///
 /// Used by paths that need the hash for downstream broadcast or mirror
 /// updates (e.g. the Pod's `SessionLogSink`).
-pub async fn append_entry_with_hash(
+pub fn append_entry_with_hash(
     store: &impl Store,
     session_id: SessionId,
     head_hash: &mut Option<EntryHash>,
@@ -488,7 +476,7 @@ pub async fn append_entry_with_hash(
         prev_hash: head_hash.clone(),
         entry,
     };
-    store.append(session_id, &hashed_entry).await?;
+    store.append(session_id, &hashed_entry)?;
     *head_hash = Some(hash.clone());
     Ok(hash)
 }

crates/session-store/src/session_log.rs

@@ -15,6 +15,7 @@ use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 
 use crate::logged_item::LoggedItem;
+use crate::system_item::SystemItem;
 
 /// SHA-256 hash identifying a specific log entry in the chain.
 ///
@@ -119,13 +120,37 @@ pub enum LogEntry {
     /// history; the worker layer never sees segments directly.
     UserInput { ts: u64, segments: Vec<Segment> },
 
-    /// Assistant response items added to history (worker.rs:1040-1041).
+    /// One assistant-side item appended to history — assistant message,
+    /// reasoning, or tool call. Singular: one entry per history item so
+    /// the wire-side `Event::*` lane and on-disk LogEntry stay 1:1.
+    AssistantItem { ts: u64, item: LoggedItem },
+
+    /// One tool-execution result appended to history.
+    ToolResult { ts: u64, item: LoggedItem },
+
+    /// One typed agent-injected system item: notification, child-Pod
+    /// lifecycle event, `@<path>` / `#<slug>` / `/<slug>` resolution
+    /// payload. Each `SystemItem` carries kind metadata that the LLM
+    /// itself never sees (the LLM gets `Item::system_message` with the
+    /// item's denormalised `body`), but live clients and replay paths
+    /// dispatch on `kind` for typed rendering.
+    SystemItem { ts: u64, item: SystemItem },
+
+    /// Legacy plural form: kept **read-only** so old session logs still
+    /// open. New writes always use the singular `AssistantItem`. Items
+    /// are flattened on replay.
     AssistantItems { ts: u64, items: Vec<LoggedItem> },
 
-    /// Tool execution results added to history (worker.rs:897-900, 1072-1076).
+    /// Legacy plural form: kept **read-only**. New writes use the
+    /// singular `ToolResult`.
     ToolResults { ts: u64, items: Vec<LoggedItem> },
 
-    /// Items injected by `on_turn_end` hook via `ContinueWithMessages` (worker.rs:1055).
+    /// Legacy plural form: kept **read-only**. New writes use the
+    /// singular `SystemItem`.
+    SystemItems { ts: u64, items: Vec<SystemItem> },
+
+    /// Legacy pre-`SystemItem*` form. Deserialize-only. Items are
+    /// flattened to `Item::system_message` on replay.
     HookInjectedItems { ts: u64, items: Vec<LoggedItem> },
 
     /// Turn boundary. Records the turn count after increment.
@@ -270,12 +295,26 @@ pub fn collect_state(entries: &[HashedEntry]) -> RestoredState {
                 state.history.push(Item::user_message(text));
                 state.user_segments.push(segments.clone());
             }
+            LogEntry::AssistantItem { item, .. } => {
+                state.history.push(Item::from(item.clone()));
+            }
+            LogEntry::ToolResult { item, .. } => {
+                state.history.push(Item::from(item.clone()));
+            }
+            LogEntry::SystemItem { item, .. } => {
+                state.history.push(item.to_history_item());
+            }
             LogEntry::AssistantItems { items, .. } => {
                 state.history.extend(items.iter().cloned().map(Item::from));
             }
             LogEntry::ToolResults { items, .. } => {
                 state.history.extend(items.iter().cloned().map(Item::from));
             }
+            LogEntry::SystemItems { items, .. } => {
+                state
+                    .history
+                    .extend(items.iter().map(|si| si.to_history_item()));
+            }
             LogEntry::HookInjectedItems { items, .. } => {
                 state.history.extend(items.iter().cloned().map(Item::from));
             }

crates/session-store/src/store.rs

@@ -1,12 +1,18 @@
 //! Persistence backend abstraction.
 //!
-//! [`Store`] defines the async interface for reading and writing session logs.
+//! [`Store`] defines the sync interface for reading and writing session logs.
 //! Implementations handle the physical storage (filesystem, database, etc.).
+//!
+//! Sync (rather than async) is intentional: a session log append is a single
+//! `< 1 KiB` line on local fs and completes well below a millisecond. Going
+//! through `tokio::fs` would force every caller — including `Worker`'s sync
+//! `on_history_append` callback — to bridge sync → async via a channel +
+//! drain task. Keeping the store sync lets the worker callback, Pod commit
+//! paths, and `PodInterceptor` all share one direct `append_entry` call.
 
 use crate::SessionId;
 use crate::event_trace::TraceEntry;
 use crate::session_log::{EntryHash, HashedEntry};
-use std::future::Future;
 
 /// Errors from the persistence store.
 #[derive(Debug, thiserror::Error)]
@@ -24,49 +30,31 @@ pub enum StoreError {
     Corrupt { line: usize, message: String },
 }
 
-/// Async persistence backend for session logs.
+/// Sync persistence backend for session logs.
 ///
 /// All methods take `&self` — implementations should use interior mutability
 /// (e.g., append-mode file handles) when needed.
 pub trait Store: Send + Sync {
     /// Append a single hashed entry to the session log.
-    fn append(
-        &self,
-        id: SessionId,
-        entry: &HashedEntry,
-    ) -> impl Future<Output = Result<(), StoreError>> + Send;
+    fn append(&self, id: SessionId, entry: &HashedEntry) -> Result<(), StoreError>;
 
     /// Read all hashed entries for a session, in order.
-    fn read_all(
-        &self,
-        id: SessionId,
-    ) -> impl Future<Output = Result<Vec<HashedEntry>, StoreError>> + Send;
+    fn read_all(&self, id: SessionId) -> Result<Vec<HashedEntry>, StoreError>;
 
     /// List all session IDs, most recent first.
-    fn list_sessions(&self) -> impl Future<Output = Result<Vec<SessionId>, StoreError>> + Send;
+    fn list_sessions(&self) -> Result<Vec<SessionId>, StoreError>;
 
     /// Create a new session with initial entries.
-    fn create_session(
-        &self,
-        id: SessionId,
-        entries: &[HashedEntry],
-    ) -> impl Future<Output = Result<(), StoreError>> + Send;
+    fn create_session(&self, id: SessionId, entries: &[HashedEntry]) -> Result<(), StoreError>;
 
     /// Check if a session exists.
-    fn exists(&self, id: SessionId) -> impl Future<Output = Result<bool, StoreError>> + Send;
+    fn exists(&self, id: SessionId) -> Result<bool, StoreError>;
 
     /// Read the hash of the last entry in a session (the head).
     ///
     /// Returns `None` if the session is empty.
-    fn read_head_hash(
-        &self,
-        id: SessionId,
-    ) -> impl Future<Output = Result<Option<EntryHash>, StoreError>> + Send;
+    fn read_head_hash(&self, id: SessionId) -> Result<Option<EntryHash>, StoreError>;
 
     /// Append a trace entry to the debug event trace file.
-    fn append_trace(
-        &self,
-        id: SessionId,
-        entry: &TraceEntry,
-    ) -> impl Future<Output = Result<(), StoreError>> + Send;
+    fn append_trace(&self, id: SessionId, entry: &TraceEntry) -> Result<(), StoreError>;
 }

crates/session-store/src/system_item.rs

@@ -0,0 +1,199 @@
+//! Typed system-message items injected by the agent system.
+//!
+//! Items in worker history with `role:system` are never produced by the
+//! LLM — they are always inserted by the Pod itself (notifications,
+//! file/knowledge/workflow ref resolutions, child-pod lifecycle events,
+//! future `<system-reminder>` tags, …). [`SystemItem`] carries the
+//! typed shape of each such injection so clients can dispatch on
+//! `kind` instead of parsing text prefixes like `[Notification] …` or
+//! `[File: …]`.
+//!
+//! Persisted as the payload of [`crate::LogEntry::SystemItem`] (one
+//! entry per item), and broadcast live as the payload of
+//! `Event::SystemItem` on the wire.
+//!
+//! For LLM context replay, each `SystemItem` reduces to an
+//! `Item::system_message(...)` whose body matches the legacy free-text
+//! shape (see [`SystemItem::history_text`]). The kind metadata is
+//! preserved only on the log/wire side; the LLM still sees plain
+//! system-message text.
+
+use llm_worker::llm_client::types::Item;
+use protocol::PodEvent;
+use serde::{Deserialize, Serialize};
+
+/// One agent-injected system item, tagged by origin.
+///
+/// Each variant carries the kind-specific raw data clients use for
+/// typed rendering (`Notification.message`, `PodEvent.event`, file
+/// path / knowledge slug / workflow slug / etc.), plus a pre-rendered
+/// `body` (where applicable) that is the exact `role:system` text the
+/// LLM actually saw at commit time. `body` is denormalised so that
+/// session log replay reconstructs worker history byte-identical to
+/// what was on the wire — even when prompt overrides (e.g. custom
+/// `notify_wrapper` template) re-shape the live rendering on a later
+/// resume.
+///
+/// New variants get added here as fresh injection kinds come online
+/// (e.g. `Reminder`). The `kind` JSON tag is the snake_case form of
+/// the variant name.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "kind", rename_all = "snake_case")]
+pub enum SystemItem {
+    /// Free-form notification sent in by an external caller via
+    /// `Method::Notify`. `message` is the raw caller-supplied text;
+    /// `body` is the wrapped LLM-context form (Pod renders it via
+    /// `notify_wrapper` at commit time).
+    Notification { message: String, body: String },
+
+    /// Lifecycle event reported by a child Pod via `Method::PodEvent`.
+    /// `event` is the typed payload (so the TUI can render per-child
+    /// banners without re-parsing); `body` is the wrapped LLM-context
+    /// form (same `notify_wrapper` path as `Notification`).
+    PodEvent { event: PodEvent, body: String },
+
+    /// `@<path>` file reference resolution. `body` is the rendered
+    /// LLM-context text (`[File: <path>]\n…` for regular files,
+    /// `[Dir: <path>]\n…` for directory listings, possibly with a
+    /// truncation hint) so replay reconstructs worker history
+    /// byte-identical to what was sent.
+    FileAttachment { path: String, body: String },
+
+    /// `#<slug>` Knowledge reference resolution. `body` is the
+    /// rendered text the LLM saw (Pod composes the `[Knowledge: …]`
+    /// header + body).
+    Knowledge { slug: String, body: String },
+
+    /// `/<slug>` Workflow invocation. `body` is the workflow's
+    /// prompt body materialized into the LLM context.
+    Workflow { slug: String, body: String },
+}
+
+impl SystemItem {
+    /// Free-text body the LLM sees inside its `role:system` message
+    /// for this item. Returns the variant's stored `body` verbatim.
+    pub fn history_text(&self) -> String {
+        match self {
+            SystemItem::Notification { body, .. } => body.clone(),
+            SystemItem::PodEvent { body, .. } => body.clone(),
+            SystemItem::FileAttachment { body, .. } => body.clone(),
+            SystemItem::Knowledge { body, .. } => body.clone(),
+            SystemItem::Workflow { body, .. } => body.clone(),
+        }
+    }
+
+    /// Materialize this `SystemItem` as the `Item::system_message`
+    /// form that lands in worker history.
+    pub fn to_history_item(&self) -> Item {
+        Item::system_message(self.history_text())
+    }
+
+    /// Short human-readable label used for diagnostics. Not on the
+    /// wire — keep flexible.
+    pub fn kind_label(&self) -> &'static str {
+        match self {
+            SystemItem::Notification { .. } => "notification",
+            SystemItem::PodEvent { .. } => "pod_event",
+            SystemItem::FileAttachment { .. } => "file_attachment",
+            SystemItem::Knowledge { .. } => "knowledge",
+            SystemItem::Workflow { .. } => "workflow",
+        }
+    }
+}
+
+/// Render a `PodEvent` as the one-line notification text the agent
+/// sees. Centralised here (rather than at the controller's render
+/// site) so persistence and broadcast share the same rendering.
+pub fn render_pod_event(event: &PodEvent) -> String {
+    match event {
+        PodEvent::TurnEnded { pod_name } => format!("pod `{pod_name}` finished a turn"),
+        PodEvent::Errored { pod_name, message } => {
+            format!("pod `{pod_name}` errored: {message}")
+        }
+        PodEvent::ShutDown { pod_name } => format!("pod `{pod_name}` shut down"),
+        PodEvent::ScopeSubDelegated {
+            parent_pod,
+            sub_pod,
+            ..
+        } => {
+            format!("pod `{parent_pod}` sub-delegated scope to `{sub_pod}`")
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn notification_history_text_returns_stored_body() {
+        let item = SystemItem::Notification {
+            message: "child done".into(),
+            body: "[Notification]\nchild done\n\n(non-blocking hint…)".into(),
+        };
+        assert_eq!(
+            item.history_text(),
+            "[Notification]\nchild done\n\n(non-blocking hint…)"
+        );
+    }
+
+    #[test]
+    fn pod_event_history_text_returns_stored_body() {
+        let item = SystemItem::PodEvent {
+            event: PodEvent::TurnEnded {
+                pod_name: "child".into(),
+            },
+            body: "[Notification]\npod `child` finished a turn\n\n(non-blocking hint…)".into(),
+        };
+        assert!(item.history_text().starts_with("[Notification]\n"));
+        assert!(item.history_text().contains("`child`"));
+    }
+
+    #[test]
+    fn file_attachment_history_text_returns_stored_body() {
+        let item = SystemItem::FileAttachment {
+            path: "src/main.rs".into(),
+            body: "[File: src/main.rs]\nfn main() {}".into(),
+        };
+        assert_eq!(item.history_text(), "[File: src/main.rs]\nfn main() {}");
+    }
+
+    #[test]
+    fn round_trip_via_json() {
+        let item = SystemItem::FileAttachment {
+            path: "src/main.rs".into(),
+            body: "[File: src/main.rs]\nfn main() {}".into(),
+        };
+        let json = serde_json::to_string(&item).unwrap();
+        let parsed: SystemItem = serde_json::from_str(&json).unwrap();
+        match parsed {
+            SystemItem::FileAttachment { path, body } => {
+                assert_eq!(path, "src/main.rs");
+                assert_eq!(body, "[File: src/main.rs]\nfn main() {}");
+            }
+            other => panic!("unexpected: {other:?}"),
+        }
+    }
+
+    #[test]
+    fn round_trip_pod_event() {
+        let item = SystemItem::PodEvent {
+            event: PodEvent::TurnEnded {
+                pod_name: "child".into(),
+            },
+            body: "[Notification] pod `child` finished a turn".into(),
+        };
+        let json = serde_json::to_string(&item).unwrap();
+        let parsed: SystemItem = serde_json::from_str(&json).unwrap();
+        match parsed {
+            SystemItem::PodEvent {
+                event: PodEvent::TurnEnded { pod_name },
+                body,
+            } => {
+                assert_eq!(pod_name, "child");
+                assert!(body.contains("`child`"));
+            }
+            other => panic!("unexpected: {other:?}"),
+        }
+    }
+}

crates/session-store/tests/fs_store_test.rs

@@ -4,10 +4,10 @@ use session_store::{
     FsStore, LogEntry, Store, TraceEntry, build_chain, collect_state, new_session_id,
 };
 
-#[tokio::test]
-async fn round_trip_write_and_read() {
+#[test]
+fn round_trip_write_and_read() {
     let dir = tempfile::tempdir().unwrap();
-    let store = FsStore::new(dir.path()).await.unwrap();
+    let store = FsStore::new(dir.path()).unwrap();
     let id = new_session_id();
 
     let raw = vec![
@@ -23,9 +23,9 @@ async fn round_trip_write_and_read() {
             ts: 2000,
             segments: vec![protocol::Segment::text("Hello")],
         },
-        LogEntry::AssistantItems {
+        LogEntry::AssistantItem {
             ts: 3000,
-            items: vec![Item::assistant_message("Hi there!").into()],
+            item: Item::assistant_message("Hi there!").into(),
         },
         LogEntry::TurnEnd {
             ts: 3100,
@@ -41,11 +41,11 @@ async fn round_trip_write_and_read() {
 
     // Write entries one by one
     for entry in &entries {
-        store.append(id, entry).await.unwrap();
+        store.append(id, entry).unwrap();
     }
 
     // Read back
-    let read_back = store.read_all(id).await.unwrap();
+    let read_back = store.read_all(id).unwrap();
     assert_eq!(read_back.len(), entries.len());
 
     // Verify hashes survived round-trip
@@ -64,10 +64,10 @@ async fn round_trip_write_and_read() {
     assert!(state.head_hash.is_some());
 }
 
-#[tokio::test]
-async fn create_session_writes_all_entries() {
+#[test]
+fn create_session_writes_all_entries() {
     let dir = tempfile::tempdir().unwrap();
-    let store = FsStore::new(dir.path()).await.unwrap();
+    let store = FsStore::new(dir.path()).unwrap();
     let id = new_session_id();
 
     let entries = build_chain(&[LogEntry::SessionStart {
@@ -82,22 +82,22 @@ async fn create_session_writes_all_entries() {
         compacted_from: None,
     }]);
 
-    store.create_session(id, &entries).await.unwrap();
-    let read_back = store.read_all(id).await.unwrap();
+    store.create_session(id, &entries).unwrap();
+    let read_back = store.read_all(id).unwrap();
     assert_eq!(read_back.len(), 1);
 
     let state = collect_state(&read_back);
     assert_eq!(state.history.len(), 2);
 }
 
-#[tokio::test]
-async fn list_sessions_returns_newest_first() {
+#[test]
+fn list_sessions_returns_newest_first() {
     let dir = tempfile::tempdir().unwrap();
-    let store = FsStore::new(dir.path()).await.unwrap();
+    let store = FsStore::new(dir.path()).unwrap();
 
     let id1 = new_session_id();
     // Small delay to ensure different UUID v7 timestamps
-    tokio::time::sleep(std::time::Duration::from_millis(2)).await;
+    std::thread::sleep(std::time::Duration::from_millis(2));
     let id2 = new_session_id();
 
     let entries1 = build_chain(&[LogEntry::SessionStart {
@@ -117,22 +117,22 @@ async fn list_sessions_returns_newest_first() {
         compacted_from: None,
     }]);
 
-    store.append(id1, &entries1[0]).await.unwrap();
-    store.append(id2, &entries2[0]).await.unwrap();
+    store.append(id1, &entries1[0]).unwrap();
+    store.append(id2, &entries2[0]).unwrap();
 
-    let sessions = store.list_sessions().await.unwrap();
+    let sessions = store.list_sessions().unwrap();
     assert_eq!(sessions.len(), 2);
     assert_eq!(sessions[0], id2); // newest first
     assert_eq!(sessions[1], id1);
 }
 
-#[tokio::test]
-async fn exists_returns_correct_state() {
+#[test]
+fn exists_returns_correct_state() {
     let dir = tempfile::tempdir().unwrap();
-    let store = FsStore::new(dir.path()).await.unwrap();
+    let store = FsStore::new(dir.path()).unwrap();
     let id = new_session_id();
 
-    assert!(!store.exists(id).await.unwrap());
+    assert!(!store.exists(id).unwrap());
 
     let entries = build_chain(&[LogEntry::SessionStart {
         ts: 1000,
@@ -142,25 +142,25 @@ async fn exists_returns_correct_state() {
         forked_from: None,
         compacted_from: None,
     }]);
-    store.append(id, &entries[0]).await.unwrap();
+    store.append(id, &entries[0]).unwrap();
 
-    assert!(store.exists(id).await.unwrap());
+    assert!(store.exists(id).unwrap());
 }
 
-#[tokio::test]
-async fn not_found_error_for_missing_session() {
+#[test]
+fn not_found_error_for_missing_session() {
     let dir = tempfile::tempdir().unwrap();
-    let store = FsStore::new(dir.path()).await.unwrap();
+    let store = FsStore::new(dir.path()).unwrap();
     let id = new_session_id();
 
-    let result = store.read_all(id).await;
+    let result = store.read_all(id);
     assert!(result.is_err());
 }
 
-#[tokio::test]
-async fn trace_entries_in_separate_file() {
+#[test]
+fn trace_entries_in_separate_file() {
     let dir = tempfile::tempdir().unwrap();
-    let store = FsStore::new(dir.path()).await.unwrap();
+    let store = FsStore::new(dir.path()).unwrap();
     let id = new_session_id();
 
     // Write a log entry
@@ -172,7 +172,7 @@ async fn trace_entries_in_separate_file() {
         forked_from: None,
         compacted_from: None,
     }]);
-    store.append(id, &entries[0]).await.unwrap();
+    store.append(id, &entries[0]).unwrap();
 
     // Write a trace entry
     let trace = TraceEntry {
@@ -182,10 +182,10 @@ async fn trace_entries_in_separate_file() {
             llm_worker::llm_client::event::PingEvent { timestamp: None },
         ),
     };
-    store.append_trace(id, &trace).await.unwrap();
+    store.append_trace(id, &trace).unwrap();
 
     // Log should have 1 entry, unaffected by trace
-    let log = store.read_all(id).await.unwrap();
+    let log = store.read_all(id).unwrap();
     assert_eq!(log.len(), 1);
 
     // Trace file should exist separately
@@ -193,10 +193,10 @@ async fn trace_entries_in_separate_file() {
     assert!(trace_path.exists());
 }
 
-#[tokio::test]
-async fn read_head_hash_returns_last_entry_hash() {
+#[test]
+fn read_head_hash_returns_last_entry_hash() {
     let dir = tempfile::tempdir().unwrap();
-    let store = FsStore::new(dir.path()).await.unwrap();
+    let store = FsStore::new(dir.path()).unwrap();
     let id = new_session_id();
 
     let entries = build_chain(&[
@@ -215,9 +215,9 @@ async fn read_head_hash_returns_last_entry_hash() {
     ]);
 
     for entry in &entries {
-        store.append(id, entry).await.unwrap();
+        store.append(id, entry).unwrap();
     }
 
-    let head = store.read_head_hash(id).await.unwrap();
+    let head = store.read_head_hash(id).unwrap();
     assert_eq!(head.as_ref(), Some(&entries[1].hash));
 }

crates/session-store/tests/session_test.rs

@@ -84,9 +84,9 @@ impl Interceptor for PausePolicy {
     }
 }
 
-async fn make_store() -> (tempfile::TempDir, FsStore) {
+fn make_store() -> (tempfile::TempDir, FsStore) {
     let dir = tempfile::tempdir().unwrap();
-    let store = FsStore::new(dir.path()).await.unwrap();
+    let store = FsStore::new(dir.path()).unwrap();
     (dir, store)
 }
 
@@ -108,7 +108,7 @@ async fn run_and_persist(
         head_hash,
         vec![protocol::Segment::text(input)],
     )
-    .await
+    
     .unwrap();
 
     let history_before = worker.history().len();
@@ -119,10 +119,10 @@ async fn run_and_persist(
 
     let new_items = &worker.history()[history_before..];
     session_store::save_delta(store, session_id, head_hash, new_items)
-        .await
+        
         .unwrap();
     session_store::save_turn_end(store, session_id, head_hash, worker.turn_count())
-        .await
+        
         .unwrap();
 
     match &result {
@@ -134,7 +134,7 @@ async fn run_and_persist(
                 r.clone(),
                 worker.last_run_interrupted(),
             )
-            .await
+            
             .unwrap();
         }
         Err(e) => {
@@ -145,7 +145,7 @@ async fn run_and_persist(
                 e.to_string(),
                 worker.last_run_interrupted(),
             )
-            .await
+            
             .unwrap();
         }
     }
@@ -160,7 +160,7 @@ async fn run_and_persist(
 
 #[tokio::test]
 async fn session_run_logs_entries() {
-    let (_dir, store) = make_store().await;
+    let (_dir, store) = make_store();
     let client = MockLlmClient::new(simple_text_events());
     let worker = Worker::new(client);
 
@@ -172,14 +172,14 @@ async fn session_run_logs_entries() {
             history: worker.history(),
         },
     )
-    .await
+    
     .unwrap();
 
     let mut head_hash = Some(head_hash);
     let (worker, _) = run_and_persist(worker, &store, sid, &mut head_hash, "Hi").await;
     let _ = &worker;
 
-    let entries = store.read_all(sid).await.unwrap();
+    let entries = store.read_all(sid).unwrap();
 
     // SessionStart, UserInput, AssistantItems, TurnEnd, RunCompleted (at minimum)
     assert!(
@@ -217,7 +217,7 @@ async fn session_run_logs_entries() {
 
 #[tokio::test]
 async fn session_restore_round_trip() {
-    let (_dir, store) = make_store().await;
+    let (_dir, store) = make_store();
     let client = MockLlmClient::new(simple_text_events());
     let mut worker = Worker::new(client);
     worker.set_system_prompt("You are helpful.");
@@ -230,7 +230,7 @@ async fn session_restore_round_trip() {
             history: worker.history(),
         },
     )
-    .await
+    
     .unwrap();
     let mut head_hash = Some(head_hash);
 
@@ -240,7 +240,7 @@ async fn session_restore_round_trip() {
     let original_turn_count = worker.turn_count();
 
     // Restore
-    let state = session_store::restore(&store, sid).await.unwrap();
+    let state = session_store::restore(&store, sid).unwrap();
 
     assert_eq!(state.history.len(), original_history_len);
     assert_eq!(state.turn_count, original_turn_count);
@@ -250,7 +250,7 @@ async fn session_restore_round_trip() {
 
 #[tokio::test]
 async fn session_run_with_tool_call() {
-    let (_dir, store) = make_store().await;
+    let (_dir, store) = make_store();
     let client = MockLlmClient::with_responses(tool_call_events());
     let mut worker = Worker::new(client);
     worker.register_tool(weather_tool_definition());
@@ -263,29 +263,29 @@ async fn session_run_with_tool_call() {
             history: worker.history(),
         },
     )
-    .await
+    
     .unwrap();
     let mut head_hash = Some(head_hash);
 
     let (_worker, _) =
         run_and_persist(worker, &store, sid, &mut head_hash, "What's the weather?").await;
 
-    let entries = store.read_all(sid).await.unwrap();
+    let entries = store.read_all(sid).unwrap();
 
     let has_tool_results = entries
         .iter()
-        .any(|e| matches!(&e.entry, LogEntry::ToolResults { .. }));
-    assert!(has_tool_results, "should have ToolResults entry");
+        .any(|e| matches!(&e.entry, LogEntry::ToolResult { .. }));
+    assert!(has_tool_results, "should have ToolResult entry");
 
     let has_assistant = entries
         .iter()
-        .any(|e| matches!(&e.entry, LogEntry::AssistantItems { .. }));
-    assert!(has_assistant, "should have AssistantItems entry");
+        .any(|e| matches!(&e.entry, LogEntry::AssistantItem { .. }));
+    assert!(has_assistant, "should have AssistantItem entry");
 }
 
 #[tokio::test]
 async fn session_resume_after_pause() {
-    let (_dir, store) = make_store().await;
+    let (_dir, store) = make_store();
 
     // First run: tool call with pause policy → Paused
     let client = MockLlmClient::with_responses(tool_call_events());
@@ -301,7 +301,7 @@ async fn session_resume_after_pause() {
             history: worker.history(),
         },
     )
-    .await
+    
     .unwrap();
     let mut head_hash = Some(head_hash);
 
@@ -309,7 +309,7 @@ async fn session_resume_after_pause() {
     assert!(matches!(result, llm_worker::WorkerResult::Paused));
 
     // Check RunCompleted is Paused
-    let entries = store.read_all(sid).await.unwrap();
+    let entries = store.read_all(sid).unwrap();
     let has_paused = entries.iter().any(|e| {
         matches!(
             &e.entry,
@@ -322,13 +322,13 @@ async fn session_resume_after_pause() {
     assert!(has_paused, "should have Paused outcome");
 
     // Restore state and verify
-    let state = session_store::restore(&store, sid).await.unwrap();
+    let state = session_store::restore(&store, sid).unwrap();
     assert!(state.last_run_interrupted);
 }
 
 #[tokio::test]
 async fn session_fork_preserves_state() {
-    let (_dir, store) = make_store().await;
+    let (_dir, store) = make_store();
     let client = MockLlmClient::new(simple_text_events());
     let mut worker = Worker::new(client);
     worker.set_system_prompt("System prompt");
@@ -341,7 +341,7 @@ async fn session_fork_preserves_state() {
             history: worker.history(),
         },
     )
-    .await
+    
     .unwrap();
     let mut head_hash = Some(head_hash);
 
@@ -356,11 +356,11 @@ async fn session_fork_preserves_state() {
             history: worker.history(),
         },
     )
-    .await
+    
     .unwrap();
 
     // Fork should have a SessionStart with the current history
-    let fork_entries = store.read_all(fork_id).await.unwrap();
+    let fork_entries = store.read_all(fork_id).unwrap();
     assert_eq!(fork_entries.len(), 1);
     assert!(matches!(
         &fork_entries[0].entry,
@@ -374,7 +374,7 @@ async fn session_fork_preserves_state() {
 
 #[tokio::test]
 async fn session_fork_at_truncates() {
-    let (_dir, store) = make_store().await;
+    let (_dir, store) = make_store();
     let client = MockLlmClient::new(simple_text_events());
     let worker = Worker::new(client);
 
@@ -386,20 +386,20 @@ async fn session_fork_at_truncates() {
             history: worker.history(),
         },
     )
-    .await
+    
     .unwrap();
     let mut head_hash = Some(head_hash);
 
     let (_worker, _) = run_and_persist(worker, &store, sid, &mut head_hash, "Hello").await;
 
-    let all_entries = store.read_all(sid).await.unwrap();
+    let all_entries = store.read_all(sid).unwrap();
     assert!(all_entries.len() > 2);
 
     // Fork at the hash of the 2nd entry (SessionStart + UserInput)
     let at_hash = &all_entries[1].hash;
-    let fork_id = session_store::fork_at(&store, sid, at_hash).await.unwrap();
+    let fork_id = session_store::fork_at(&store, sid, at_hash).unwrap();
 
-    let fork_entries = store.read_all(fork_id).await.unwrap();
+    let fork_entries = store.read_all(fork_id).unwrap();
     assert_eq!(fork_entries.len(), 1); // Just the new SessionStart
 
     let fork_state = collect_state(&fork_entries);
@@ -413,7 +413,7 @@ async fn session_fork_at_truncates() {
 
 #[tokio::test]
 async fn session_config_changed_logged() {
-    let (_dir, store) = make_store().await;
+    let (_dir, store) = make_store();
     let client = MockLlmClient::new(vec![]);
     let mut worker = Worker::new(client);
 
@@ -425,7 +425,7 @@ async fn session_config_changed_logged() {
             history: worker.history(),
         },
     )
-    .await
+    
     .unwrap();
     let mut head_hash = Some(head_hash);
 
@@ -433,10 +433,10 @@ async fn session_config_changed_logged() {
     let new_config = RequestConfig::default().with_temperature(0.7);
     worker.set_request_config(new_config.clone());
     session_store::save_config_changed(&store, sid, &mut head_hash, &new_config)
-        .await
+        
         .unwrap();
 
-    let entries = store.read_all(sid).await.unwrap();
+    let entries = store.read_all(sid).unwrap();
     let has_config_changed = entries.iter().any(|e| {
         matches!(
             &e.entry,
@@ -448,7 +448,7 @@ async fn session_config_changed_logged() {
 
 #[tokio::test]
 async fn session_auto_forks_on_conflict() {
-    let (_dir, store) = make_store().await;
+    let (_dir, store) = make_store();
 
     // Create a session
     let client_a = MockLlmClient::new(simple_text_events());
@@ -462,7 +462,7 @@ async fn session_auto_forks_on_conflict() {
             history: worker_a.history(),
         },
     )
-    .await
+    
     .unwrap();
     let mut session_id = original_sid;
     let mut head_hash = Some(head_hash);
@@ -472,14 +472,14 @@ async fn session_auto_forks_on_conflict() {
         ts: 9999,
         segments: vec![protocol::Segment::text("Interloper")],
     };
-    let current_head = store.read_head_hash(original_sid).await.unwrap();
+    let current_head = store.read_head_hash(original_sid).unwrap();
     let hash = session_store::compute_hash(current_head.as_ref(), &extra_entry);
     let hashed = session_store::HashedEntry {
         hash,
         prev_hash: current_head,
         entry: extra_entry,
     };
-    store.append(original_sid, &hashed).await.unwrap();
+    store.append(original_sid, &hashed).unwrap();
 
     // Now head_hash is stale — ensure_head_or_fork should auto-fork
     session_store::ensure_head_or_fork(
@@ -492,18 +492,18 @@ async fn session_auto_forks_on_conflict() {
             history: worker_a.history(),
         },
     )
-    .await
+    
     .unwrap();
 
     // session_id should now be different
     assert_ne!(session_id, original_sid);
 
     // The fork session should exist and have entries
-    let fork_entries = store.read_all(session_id).await.unwrap();
+    let fork_entries = store.read_all(session_id).unwrap();
     assert!(!fork_entries.is_empty());
 
     // Original session should still have the interloper entry
-    let original_entries = store.read_all(original_sid).await.unwrap();
+    let original_entries = store.read_all(original_sid).unwrap();
     let has_interloper = original_entries
         .iter()
         .any(|e| matches!(&e.entry, LogEntry::UserInput { .. }));

crates/tui/src/app.rs

@@ -483,21 +483,13 @@ impl App {
                 self.blocks.push(Block::UserMessage { segments });
                 self.assistant_streaming = false;
             }
-            Event::Notify { message } => {
-                self.blocks.push(Block::Notify { message });
-                self.assistant_streaming = false;
-            }
-            Event::PodEvent(event) => {
-                self.blocks.push(Block::PodEvent { event });
-                self.assistant_streaming = false;
-            }
             Event::SessionRotated { entry } => {
                 self.reset_for_rotation();
                 self.apply_log_entry_raw(&entry);
                 self.assistant_streaming = false;
             }
-            Event::HookInjectedItems { entry } => {
-                self.apply_log_entry_raw(&entry);
+            Event::SystemItem { item } => {
+                self.apply_system_item(&item);
                 self.assistant_streaming = false;
             }
             Event::TurnStart { .. } => {
@@ -975,6 +967,16 @@ impl App {
                     self.blocks.push(Block::UserMessage { segments });
                 }
             }
+            session_store::LogEntry::AssistantItem { item, .. }
+            | session_store::LogEntry::ToolResult { item, .. } => {
+                let it: llm_worker::Item = item.into();
+                let item_value = serde_json::to_value(&it).expect("Item is Serialize");
+                self.push_history_item(&item_value);
+            }
+            session_store::LogEntry::SystemItem { item, .. } => {
+                let value = serde_json::to_value(&item).expect("SystemItem is Serialize");
+                self.apply_system_item(&value);
+            }
             session_store::LogEntry::AssistantItems { items, .. }
             | session_store::LogEntry::ToolResults { items, .. }
             | session_store::LogEntry::HookInjectedItems { items, .. } => {
@@ -984,11 +986,51 @@ impl App {
                     self.push_history_item(&item_value);
                 }
             }
+            session_store::LogEntry::SystemItems { items, .. } => {
+                for system_item in items {
+                    let value =
+                        serde_json::to_value(&system_item).expect("SystemItem is Serialize");
+                    self.apply_system_item(&value);
+                }
+            }
             // Non-history-bearing variants don't affect the block view.
             _ => {}
         }
     }
 
+    /// Dispatch one `SystemItem` JSON value into the appropriate block.
+    ///
+    /// Kind-based routing replaces the old free-text `[Notification]` /
+    /// `[File: …]` parsing path: each kind maps directly to a typed
+    /// block (`Block::Notify`, `Block::PodEvent`, …).
+    fn apply_system_item(&mut self, value: &serde_json::Value) {
+        let Ok(item) = serde_json::from_value::<session_store::SystemItem>(value.clone()) else {
+            // Unknown / forward-compat shape: fall back to rendering the
+            // raw text payload (if any) as a generic system message.
+            if let Some(text) = value.get("body").and_then(|b| b.as_str()) {
+                self.task_store.apply_system_message_text(text);
+                self.blocks.push(Block::SystemMessage {
+                    text: text.to_owned(),
+                });
+            }
+            return;
+        };
+        match item {
+            session_store::SystemItem::Notification { message, .. } => {
+                self.blocks.push(Block::Notify { message });
+            }
+            session_store::SystemItem::PodEvent { event, .. } => {
+                self.blocks.push(Block::PodEvent { event });
+            }
+            session_store::SystemItem::FileAttachment { body, .. }
+            | session_store::SystemItem::Knowledge { body, .. }
+            | session_store::SystemItem::Workflow { body, .. } => {
+                self.task_store.apply_system_message_text(&body);
+                self.blocks.push(Block::SystemMessage { text: body });
+            }
+        }
+    }
+
     /// Sweep all current tool-call blocks: any that never resolved into
     /// a Done / Error state get marked Incomplete. Called after a
     /// snapshot replay so dangling in-flight tool calls in the seed
@@ -1422,18 +1464,14 @@ mod completion_flow_tests {
     }
 
     #[test]
-    fn live_hook_injected_items_event_appends_system_message_block() {
+    fn live_system_item_workflow_appends_system_message_block() {
         let mut app = App::new("test".into());
-        let entry = serde_json::json!({
-            "kind": "hook_injected_items",
-            "ts": 1,
-            "items": [{
-                "kind": "message",
-                "role": "system",
-                "content": [{ "kind": "text", "text": "[Workflow /build]\nRun the build" }],
-            }],
+        let item = serde_json::json!({
+            "kind": "workflow",
+            "slug": "build",
+            "body": "[Workflow /build]\nRun the build",
         });
-        app.handle_pod_event(Event::HookInjectedItems { entry });
+        app.handle_pod_event(Event::SystemItem { item });
 
         assert!(matches!(
             app.blocks.as_slice(),
@@ -1441,6 +1479,39 @@ mod completion_flow_tests {
         ));
     }
 
+    #[test]
+    fn live_system_item_notification_appends_notify_block() {
+        let mut app = App::new("test".into());
+        let item = serde_json::json!({
+            "kind": "notification",
+            "message": "hi",
+            "body": "[Notification] hi",
+        });
+        app.handle_pod_event(Event::SystemItem { item });
+        assert!(matches!(
+            app.blocks.as_slice(),
+            [Block::Notify { message }] if message == "hi"
+        ));
+    }
+
+    #[test]
+    fn live_system_item_pod_event_appends_pod_event_block() {
+        let mut app = App::new("test".into());
+        let item = serde_json::json!({
+            "kind": "pod_event",
+            "event": { "kind": "turn_ended", "pod_name": "child" },
+            "body": "[Notification] pod `child` finished a turn",
+        });
+        app.handle_pod_event(Event::SystemItem { item });
+        assert_eq!(app.blocks.len(), 1);
+        match &app.blocks[0] {
+            Block::PodEvent {
+                event: protocol::PodEvent::TurnEnded { pod_name },
+            } => assert_eq!(pod_name, "child"),
+            _ => panic!("expected a PodEvent block"),
+        }
+    }
+
     #[test]
     fn compact_done_replaces_live_block() {
         let mut app = App::new("test".into());
@@ -1577,15 +1648,13 @@ mod completion_flow_tests {
             ```json\n{\n  \"tasks\": [\n    {\n      \"taskid\": 4,\n      \
             \"status\": \"inprogress\",\n      \"subject\": \"from snapshot\",\n      \
             \"description\": \"d\"\n    }\n  ]\n}\n```\n";
-        app.handle_pod_event(Event::HookInjectedItems {
-            entry: serde_json::json!({
-                "kind": "hook_injected_items",
-                "ts": 1,
-                "items": [{
-                    "kind": "message",
-                    "role": "system",
-                    "content": [{ "kind": "text", "text": snapshot }],
-                }],
+        // Snapshot text injected as a workflow body (kind doesn't matter
+        // for task-store parsing, only the text contents do).
+        app.handle_pod_event(Event::SystemItem {
+            item: serde_json::json!({
+                "kind": "workflow",
+                "slug": "task-snapshot",
+                "body": snapshot,
             }),
         });
 

crates/tui/src/picker.rs

@@ -80,14 +80,14 @@ struct Row {
 }
 
 pub async fn run() -> Result<PickerOutcome, PickerError> {
-    let store = open_default_store().await?;
-    let ids = store.list_sessions().await?;
+    let store = open_default_store()?;
+    let ids = store.list_sessions()?;
     if ids.is_empty() {
         return Err(PickerError::NoSessions);
     }
     let mut rows: Vec<Row> = Vec::with_capacity(MAX_ROWS);
     for id in ids.into_iter().take(MAX_ROWS) {
-        let preview = build_preview(&store, id).await;
+        let preview = build_preview(&store, id);
         // Best-effort live check. A pods.json I/O hiccup downgrades
         // the row to "no badge" rather than killing the picker — the
         // user still gets to see the listing.
@@ -149,7 +149,7 @@ fn close_viewport(terminal: &mut Terminal<CrosstermBackend<io::Stdout>>) -> io::
     Ok(())
 }
 
-async fn open_default_store() -> Result<FsStore, PickerError> {
+fn open_default_store() -> Result<FsStore, PickerError> {
     let dir = manifest::paths::sessions_dir().ok_or_else(|| {
         PickerError::Io(io::Error::new(
             io::ErrorKind::NotFound,
@@ -157,11 +157,11 @@ async fn open_default_store() -> Result<FsStore, PickerError> {
              (set INSOMNIA_HOME, INSOMNIA_DATA_DIR, or HOME)",
         ))
     })?;
-    Ok(FsStore::new(&dir).await?)
+    Ok(FsStore::new(&dir)?)
 }
 
-async fn build_preview(store: &FsStore, id: SessionId) -> String {
-    match store.read_all(id).await {
+fn build_preview(store: &FsStore, id: SessionId) -> String {
+    match store.read_all(id) {
         Ok(entries) => last_message_preview(&entries).unwrap_or_else(|| "[empty]".to_string()),
         Err(_) => "[corrupt]".to_string(),
     }

crates/tui/src/spawn.rs

@@ -328,8 +328,8 @@ async fn load_resume_scope(session_id: SessionId) -> Result<ScopeConfig, SpawnEr
             "could not resolve sessions directory (set INSOMNIA_HOME, INSOMNIA_DATA_DIR, or HOME)",
         )
     })?;
-    let store = session_store::FsStore::new(&store_dir).await?;
-    let state = session_store::restore(&store, session_id).await?;
+    let store = session_store::FsStore::new(&store_dir)?;
+    let state = session_store::restore(&store, session_id)?;
     let snapshot = state
         .pod_scope
         .ok_or(SpawnError::MissingResumeScope { session_id })?;

tickets/persistence-semantics.md

@@ -79,6 +79,23 @@ llm-worker は session 概念を持たない（`Worker` は `history` / `turn_co
 - `SessionOrigin.at_hash` → `at_turn_index` (TurnEnd 由来) に置換。
 - `ensure_head_or_fork` の検知ロジックは、Segment 末尾の terminal marker entry または末尾 seq 比較に置換（形式は実装時に決める）。
 
+### 廃止前の足場 (前提)
+
+本セクションを実装に移すタイミングでは、log writer が既に sync 化されていることを前提にする (`tickets/log-entry-singular-and-direct-commit.md`)。具体的には:
+
+- `Store::append` / `read_all` 等が `std::fs` ベースの sync API
+- `SessionLogWriter::append_entry()` が sync 関数
+- `session_head` mutex は `parking_lot::Mutex` / `std::sync::Mutex`
+- `LogCommand` / drain task / Flush バリアは既に撤廃済み
+
+この状態で hash chain を廃止すると追加で取れる単純化:
+
+- **`session_head` mutex そのものを撤去できる**。 hash chain が無いので「`head_hash` を直前 entry から取得して次に渡す」 という serialize 必須の依存が消える。 1 行 < `PIPE_BUF` (Linux 4KB) の `O_APPEND` write は kernel 側で atomic に直列化されるので、 user space で mutex を持つ必要が無い
+- `session_head` が消えると Pod / interceptor / worker callback が writer ハンドルだけ持てば良くなる。 `Arc<SessionLogWriter>` は単に `Arc<Store> + sink` を抱えるだけの値で、 hot-path の競合がない
+- `compute_hash` 呼び出しが消える分、 append が serialize + open + write + close の 3 syscall まで詰まる
+
+つまり「sync 化」 が先に来て、 「hash 廃止」 で mutex まで消える、 という 2 段階の単純化になる。
+
 ## Fork: 2 種類の書き込み方
 
 Session 境界の話ではなく **元 Segment への marker 書き込みの有無**で 2 種類を分ける。Session はどちらの場合も同じで、新 Segment が同 Session 内に生える。