fix: preserve run budget across segment forks

crates/agen/src/engine.rs

@@ -179,14 +179,20 @@ pub struct Engine<C: LlmClient, S: EngineState = Mutable> {
     history: Vec<Item>,
     /// History length at lock time (only meaningful in Locked state)
     locked_prefix_len: usize,
-    /// AgentTurn count.
+    /// AgentTurn count across the lifetime of this Engine.
     ///
     /// Once retry (`agen-stream-continuation`) is implemented, an
     /// AgentTurn collapses N retried `LlmCall`s with identical input;
     /// today retry is not implemented so AgentTurn and LlmCall fire 1:1
     /// and the increment site (the LLM-call loop) is shared.
-    /// `max_turns` is interpreted as a per-`run()` AgentTurn cap.
     turn_count: usize,
+    /// AgentTurns consumed by the currently active logical run.
+    ///
+    /// A fresh [`run`](Self::run) starts at zero. Pause and Yield retain the
+    /// count for [`resume`](Self::resume), while terminal outcomes clear it.
+    /// `max_turns` is enforced against this run-scoped count rather than the
+    /// cumulative `turn_count` above.
+    active_run_turn_count: Option<usize>,
     /// LlmCall count (per-Engine running counter, monotonic). Unlike
     /// `turn_count` this never collapses retries.
     llm_call_count: usize,
@@ -268,6 +274,20 @@ impl<C: LlmClient, S: EngineState> Engine<C, S> {
         self.last_run_interrupted = false;
     }
 
+    fn start_logical_run(&mut self) {
+        self.active_run_turn_count = Some(0);
+    }
+
+    fn ensure_logical_run(&mut self) {
+        self.active_run_turn_count.get_or_insert(0);
+    }
+
+    fn finish_logical_run(&mut self, result: &Result<EngineResult, EngineError>) {
+        if !matches!(result, Ok(EngineResult::Paused) | Ok(EngineResult::Yielded)) {
+            self.active_run_turn_count = None;
+        }
+    }
+
     fn drain_cancel_queue(&mut self) {
         while self.cancel_rx.try_recv().is_ok() {}
     }
@@ -650,6 +670,23 @@ impl<C: LlmClient, S: EngineState> Engine<C, S> {
         self.turn_count
     }
 
+    /// Get the AgentTurns consumed by an interrupted logical run.
+    ///
+    /// `Some` is retained only while Pause or Yield permits a later
+    /// [`resume`](Self::resume). Terminal outcomes return this to `None`.
+    pub fn active_run_turn_count(&self) -> Option<usize> {
+        self.active_run_turn_count
+    }
+
+    /// Restore the persisted turn budget of an interrupted logical run.
+    ///
+    /// Session owners restore this together with the cumulative turn count and
+    /// history. `None` means there is no resumable logical run and the next
+    /// [`resume`](Self::resume) starts a fresh budget.
+    pub fn set_active_run_turn_count(&mut self, turn_count: Option<usize>) {
+        self.active_run_turn_count = turn_count;
+    }
+
     /// Get the current LlmCall count (per-Engine running counter, never
     /// collapsed by retry).
     pub fn llm_call_count(&self) -> usize {
@@ -1123,6 +1160,19 @@ impl<C: LlmClient, S: EngineState> Engine<C, S> {
                 return Err(EngineError::Cancelled);
             }
 
+            if let Some(max) = self.max_turns
+                && self.active_run_turn_count.unwrap_or(0) >= max as usize
+            {
+                info!(
+                    active_run_turn_count = self.active_run_turn_count.unwrap_or(0),
+                    total_turn_count = self.turn_count,
+                    max_turns = max,
+                    "Logical run turn limit reached"
+                );
+                self.last_run_interrupted = false;
+                return Ok(EngineResult::LimitReached);
+            }
+
             let current_turn = self.turn_count;
             if !continuing_stream {
                 debug!(turn = current_turn, "Turn start");
@@ -1314,6 +1364,7 @@ impl<C: LlmClient, S: EngineState> Engine<C, S> {
                 cb(current_turn);
             }
             self.turn_count += 1;
+            *self.active_run_turn_count.get_or_insert(0) += 1;
 
             // Collect and commit assistant items. Routed through
             // `append_history_items` so observers see each item as it lands.
@@ -1344,18 +1395,6 @@ impl<C: LlmClient, S: EngineState> Engine<C, S> {
             if let Some(result) = self.execute_and_commit_tools(tool_calls).await? {
                 return Ok(result);
             }
-
-            if let Some(max) = self.max_turns {
-                if self.turn_count >= max as usize {
-                    info!(
-                        turn_count = self.turn_count,
-                        max_turns = max,
-                        "Turn limit reached"
-                    );
-                    self.last_run_interrupted = false;
-                    return Ok(EngineResult::LimitReached);
-                }
-            }
         }
     }
 
@@ -1664,6 +1703,7 @@ impl<C: LlmClient> Engine<C, Mutable> {
             history: Vec::new(),
             locked_prefix_len: 0,
             turn_count: 0,
+            active_run_turn_count: None,
             llm_call_count: 0,
             tool_execution_batch_count: 0,
             max_turns: None,
@@ -1866,6 +1906,9 @@ impl<C: LlmClient> Engine<C, Mutable> {
     /// Set the last_run_interrupted flag (for session restoration)
     pub fn set_last_run_interrupted(&mut self, interrupted: bool) {
         self.last_run_interrupted = interrupted;
+        if !interrupted {
+            self.active_run_turn_count = None;
+        }
     }
 
     /// Apply configuration (reserved for future extensions)
@@ -1934,6 +1977,7 @@ impl<C: LlmClient> Engine<C, Mutable> {
             history: self.history,
             locked_prefix_len,
             turn_count: self.turn_count,
+            active_run_turn_count: self.active_run_turn_count,
             llm_call_count: self.llm_call_count,
             tool_execution_batch_count: self.tool_execution_batch_count,
             max_turns: self.max_turns,
@@ -1974,6 +2018,8 @@ impl<C: LlmClient> Engine<C, Locked> {
         &mut self,
         user_input: impl Into<String>,
     ) -> Result<EngineResult, EngineError> {
+        // Supplying new user input abandons any paused/yielded logical run.
+        self.active_run_turn_count = None;
         self.reset_interruption_state();
         // Interceptor: on_prompt_submit
         let mut user_item = Item::user_message(user_input);
@@ -1991,8 +2037,11 @@ impl<C: LlmClient> Engine<C, Locked> {
         if !extras.is_empty() {
             self.append_history_items(extras)?;
         }
+        self.start_logical_run();
         let result = self.run_turn_loop().await;
-        self.finalize_interruption(result).await
+        let result = self.finalize_interruption(result).await;
+        self.finish_logical_run(&result);
+        result
     }
 
     /// Resume execution (from Paused state)
@@ -2000,8 +2049,11 @@ impl<C: LlmClient> Engine<C, Locked> {
     /// Resumes turn processing from current state without adding a new user message.
     pub async fn resume(&mut self) -> Result<EngineResult, EngineError> {
         self.reset_interruption_state();
+        self.ensure_logical_run();
         let result = self.run_turn_loop().await;
-        self.finalize_interruption(result).await
+        let result = self.finalize_interruption(result).await;
+        self.finish_logical_run(&result);
+        result
     }
 
     /// Get the prefix length at lock time
@@ -2027,6 +2079,7 @@ impl<C: LlmClient> Engine<C, Locked> {
             history: self.history,
             locked_prefix_len: 0,
             turn_count: self.turn_count,
+            active_run_turn_count: self.active_run_turn_count,
             llm_call_count: self.llm_call_count,
             tool_execution_batch_count: self.tool_execution_batch_count,
             max_turns: self.max_turns,

crates/agen/tests/engine_state_test.rs

@@ -9,9 +9,12 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::{Arc, Mutex};
 
 use agen::Item;
+use agen::interceptor::{
+    Interceptor, PreRequestAction, PreToolAction, ToolCallInfo, TurnEndAction,
+};
 use agen::llm_client::event::{Event, ResponseStatus, StatusEvent};
 use agen::tool::{Tool, ToolDefinition, ToolError, ToolMeta, ToolOutput};
-use agen::{Engine, EngineError};
+use agen::{Engine, EngineError, EngineResult};
 use async_trait::async_trait;
 use common::MockLlmClient;
 
@@ -561,3 +564,185 @@ fn test_system_prompt_change_after_unlock() {
     let relocked = unlocked.lock();
     assert_eq!(relocked.get_system_prompt(), Some("New prompt"));
 }
+
+fn completed_text_events() -> Vec<Event> {
+    vec![
+        Event::text_block_start(0),
+        Event::text_delta(0, "done"),
+        Event::text_block_stop(0, None),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ]
+}
+
+struct YieldOnce {
+    calls: AtomicUsize,
+}
+
+#[async_trait]
+impl Interceptor for YieldOnce {
+    async fn pre_llm_request(&self, _context: &mut Vec<Item>) -> PreRequestAction {
+        if self.calls.fetch_add(1, Ordering::SeqCst) == 0 {
+            PreRequestAction::Yield
+        } else {
+            PreRequestAction::Continue
+        }
+    }
+}
+
+struct PauseToolOnce {
+    calls: AtomicUsize,
+}
+
+#[async_trait]
+impl Interceptor for PauseToolOnce {
+    async fn pre_tool_call(&self, _info: &mut ToolCallInfo) -> PreToolAction {
+        if self.calls.fetch_add(1, Ordering::SeqCst) == 0 {
+            PreToolAction::Pause
+        } else {
+            PreToolAction::Continue
+        }
+    }
+}
+
+struct ContinueTurnOnce {
+    calls: AtomicUsize,
+}
+
+#[async_trait]
+impl Interceptor for ContinueTurnOnce {
+    async fn on_turn_end(&self, _history: &[Item]) -> TurnEndAction {
+        if self.calls.fetch_add(1, Ordering::SeqCst) == 0 {
+            TurnEndAction::ContinueWithMessages(vec![Item::system_message("continue")])
+        } else {
+            TurnEndAction::Finish
+        }
+    }
+}
+
+#[tokio::test]
+async fn max_turns_is_scoped_to_each_fresh_run() {
+    let responses = vec![completed_text_events(), completed_text_events()];
+    let mut engine = Engine::new(MockLlmClient::with_responses(responses));
+    engine.set_max_turns(Some(1));
+    let mut engine = engine.lock();
+
+    assert_eq!(engine.run("first").await.unwrap(), EngineResult::Finished);
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), None);
+
+    assert_eq!(engine.run("second").await.unwrap(), EngineResult::Finished);
+    assert_eq!(engine.turn_count(), 2);
+    assert_eq!(engine.active_run_turn_count(), None);
+}
+
+#[tokio::test]
+async fn yielded_resume_keeps_the_same_unspent_turn_budget() {
+    let mut engine = Engine::new(MockLlmClient::new(completed_text_events()));
+    engine.set_max_turns(Some(1));
+    engine.set_interceptor(YieldOnce {
+        calls: AtomicUsize::new(0),
+    });
+    let mut engine = engine.lock();
+
+    assert_eq!(engine.run("start").await.unwrap(), EngineResult::Yielded);
+    assert_eq!(engine.turn_count(), 0);
+    assert_eq!(engine.active_run_turn_count(), Some(0));
+
+    assert_eq!(engine.resume().await.unwrap(), EngineResult::Finished);
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), None);
+}
+
+#[tokio::test]
+async fn paused_tool_resume_does_not_reset_the_consumed_turn_budget() {
+    let events = vec![
+        Event::tool_use_start(0, "call_1", "count_tool"),
+        Event::tool_input_delta(0, "{}"),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ];
+    let tool = CountingTool::new("count_tool");
+    let mut engine = Engine::new(MockLlmClient::new(events));
+    engine.set_max_turns(Some(1));
+    engine.register_tool(tool.definition());
+    engine.set_interceptor(PauseToolOnce {
+        calls: AtomicUsize::new(0),
+    });
+    let mut engine = engine.lock();
+
+    assert_eq!(engine.run("call it").await.unwrap(), EngineResult::Paused);
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), Some(1));
+    assert_eq!(tool.call_count(), 0);
+
+    assert_eq!(engine.resume().await.unwrap(), EngineResult::LimitReached);
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), None);
+    assert_eq!(tool.call_count(), 1, "the consumed turn's tool still runs");
+}
+
+#[tokio::test]
+async fn fresh_input_abandons_a_paused_run_and_starts_a_new_budget() {
+    let tool_events = vec![
+        Event::tool_use_start(0, "call_1", "count_tool"),
+        Event::tool_input_delta(0, "{}"),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ];
+    let client = MockLlmClient::with_responses(vec![tool_events, completed_text_events()]);
+    let tool = CountingTool::new("count_tool");
+    let mut engine = Engine::new(client);
+    engine.set_max_turns(Some(1));
+    engine.register_tool(tool.definition());
+    engine.set_interceptor(PauseToolOnce {
+        calls: AtomicUsize::new(0),
+    });
+    let mut engine = engine.lock();
+
+    assert_eq!(engine.run("pause").await.unwrap(), EngineResult::Paused);
+    assert_eq!(engine.active_run_turn_count(), Some(1));
+
+    assert_eq!(engine.run("replace").await.unwrap(), EngineResult::Finished);
+    assert_eq!(engine.turn_count(), 2);
+    assert_eq!(engine.active_run_turn_count(), None);
+    assert_eq!(tool.call_count(), 1, "pending-tool semantics are unchanged");
+}
+
+#[tokio::test]
+async fn interceptor_continuation_consumes_the_logical_run_budget() {
+    let mut engine = Engine::new(MockLlmClient::new(completed_text_events()));
+    engine.set_max_turns(Some(1));
+    engine.set_interceptor(ContinueTurnOnce {
+        calls: AtomicUsize::new(0),
+    });
+    let mut engine = engine.lock();
+
+    assert_eq!(
+        engine.run("start").await.unwrap(),
+        EngineResult::LimitReached
+    );
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.llm_call_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), None);
+}
+
+#[tokio::test]
+async fn restored_active_run_budget_is_enforced_before_another_llm_call() {
+    let mut engine = Engine::new(MockLlmClient::new(completed_text_events()));
+    engine.set_max_turns(Some(1));
+    engine.set_turn_count(7);
+    engine.set_last_run_interrupted(true);
+    engine.set_active_run_turn_count(Some(1));
+    let mut engine = engine.lock();
+
+    assert_eq!(engine.resume().await.unwrap(), EngineResult::LimitReached);
+    assert_eq!(engine.turn_count(), 7);
+    assert_eq!(engine.llm_call_count(), 0);
+    assert_eq!(engine.active_run_turn_count(), None);
+}

crates/session-store/src/segment.rs

@@ -307,6 +307,7 @@ pub fn save_run_completed(
     segment_id: SegmentId,
     result: EngineResult,
     interrupted: bool,
+    active_run_turn_count: Option<usize>,
 ) -> Result<(), StoreError> {
     append_entry(
         store,
@@ -316,6 +317,7 @@ pub fn save_run_completed(
             ts: segment_log::now_millis(),
             interrupted,
             result,
+            active_run_turn_count,
         },
     )
 }

crates/session-store/src/segment_log.rs

@@ -125,11 +125,16 @@ pub enum LogEntry {
     TurnEnd { ts: u64, turn_count: usize },
 
     /// `run()` / `resume()` が `EngineResult` で正常終了した。
-    /// Audit-only metadata: replay は `interrupted` のみ反映する。
+    /// Replay restores both interruption state and any resumable logical-run
+    /// turn budget.
     RunCompleted {
         ts: u64,
         interrupted: bool,
         result: EngineResult,
+        /// AgentTurns consumed by a paused/yielded logical run. Terminal
+        /// outcomes persist `None`.
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        active_run_turn_count: Option<usize>,
     },
 
     /// `run()` / `resume()` が `EngineError` で終了した。
@@ -141,6 +146,15 @@ pub enum LogEntry {
         message: String,
     },
 
+    /// Restores an active logical-run budget at a segment boundary, notably
+    /// after compaction replaced the segment that held the original Invoke and
+    /// RunCompleted entries.
+    ActiveRunCheckpoint {
+        ts: u64,
+        active_turn_count: usize,
+        total_turn_count: usize,
+    },
+
     /// A paused interrupted turn was explicitly abandoned without calling
     /// `run()` or `resume()` again. Replay clears the interrupted marker so
     /// the restored Worker is idle and future user input starts a normal new turn.
@@ -209,6 +223,8 @@ pub struct RestoredState {
     pub config: RequestConfig,
     pub history: Vec<Item>,
     pub turn_count: usize,
+    /// AgentTurns consumed by the active paused/yielded logical run.
+    pub active_run_turn_count: Option<usize>,
     pub last_run_interrupted: bool,
     /// Number of entries replayed. `0` means the segment log was empty.
     /// Writers track their own append count via the same counter so
@@ -238,6 +254,7 @@ pub fn collect_state(entries: &[LogEntry]) -> RestoredState {
         config: RequestConfig::default(),
         history: Vec::new(),
         turn_count: 0,
+        active_run_turn_count: None,
         last_run_interrupted: false,
         entries_count: 0,
         usage_history: Vec::new(),
@@ -265,6 +282,7 @@ pub fn collect_state(entries: &[LogEntry]) -> RestoredState {
                 // A terminal run record below clears or refines this. If the
                 // log ends first, restore must treat the turn as interrupted.
                 state.last_run_interrupted = true;
+                state.active_run_turn_count = Some(0);
             }
             LogEntry::UserInput {
                 segments,
@@ -290,16 +308,44 @@ pub fn collect_state(entries: &[LogEntry]) -> RestoredState {
                 state.history.push(item.to_history_item());
             }
             LogEntry::TurnEnd { turn_count, .. } => {
+                if let Some(active_turn_count) = &mut state.active_run_turn_count {
+                    *active_turn_count += turn_count.saturating_sub(state.turn_count);
+                }
                 state.turn_count = *turn_count;
             }
-            LogEntry::RunCompleted { interrupted, .. } => {
+            LogEntry::RunCompleted {
+                interrupted,
+                result,
+                active_run_turn_count,
+                ..
+            } => {
                 state.last_run_interrupted = *interrupted;
+                if *interrupted && matches!(result, EngineResult::Paused | EngineResult::Yielded) {
+                    // Legacy entries omit the explicit field; retain the
+                    // Invoke/TurnEnd-derived count in that case.
+                    if let Some(turn_count) = active_run_turn_count {
+                        state.active_run_turn_count = Some(*turn_count);
+                    }
+                } else {
+                    state.active_run_turn_count = None;
+                }
             }
             LogEntry::RunErrored { interrupted, .. } => {
                 state.last_run_interrupted = *interrupted;
+                state.active_run_turn_count = None;
+            }
+            LogEntry::ActiveRunCheckpoint {
+                active_turn_count,
+                total_turn_count,
+                ..
+            } => {
+                state.active_run_turn_count = Some(*active_turn_count);
+                state.turn_count = *total_turn_count;
+                state.last_run_interrupted = true;
             }
             LogEntry::PausedTurnAbandoned { .. } => {
                 state.last_run_interrupted = false;
+                state.active_run_turn_count = None;
             }
             LogEntry::ConfigChanged { config, .. } => {
                 state.config = config.clone();
@@ -397,6 +443,7 @@ mod tests {
                 ts: 3200,
                 interrupted: false,
                 result: EngineResult::Finished,
+                active_run_turn_count: None,
             },
         ]);
         assert_eq!(state.history.len(), 2);
@@ -695,10 +742,93 @@ mod tests {
                 ts: 100,
                 interrupted: true,
                 result: EngineResult::Paused,
+                active_run_turn_count: Some(1),
             },
             LogEntry::PausedTurnAbandoned { ts: 200 },
         ]);
         assert!(!state.last_run_interrupted);
+        assert_eq!(state.active_run_turn_count, None);
+    }
+
+    #[test]
+    fn replay_restores_active_run_budget_across_compaction_checkpoint() {
+        let state = collect_state(&[
+            LogEntry::SegmentStart {
+                ts: 0,
+                session_id: uuid::Uuid::nil(),
+                system_prompt: None,
+                config: RequestConfig::default(),
+                history: vec![],
+                forked_from: None,
+                compacted_from: None,
+            },
+            LogEntry::ActiveRunCheckpoint {
+                ts: 100,
+                active_turn_count: 3,
+                total_turn_count: 9,
+            },
+        ]);
+
+        assert_eq!(state.turn_count, 9);
+        assert_eq!(state.active_run_turn_count, Some(3));
+        assert!(state.last_run_interrupted);
+    }
+
+    #[test]
+    fn legacy_interrupted_run_derives_budget_from_invoke_and_turn_end() {
+        let entry: LogEntry = serde_json::from_value(serde_json::json!({
+            "kind": "run_completed",
+            "ts": 300,
+            "interrupted": true,
+            "result": "paused"
+        }))
+        .expect("legacy run-completed entry");
+        let state = collect_state(&[
+            LogEntry::SegmentStart {
+                ts: 0,
+                session_id: uuid::Uuid::nil(),
+                system_prompt: None,
+                config: RequestConfig::default(),
+                history: vec![],
+                forked_from: None,
+                compacted_from: None,
+            },
+            LogEntry::Invoke {
+                ts: 100,
+                trigger: InvokeKind::UserSend,
+            },
+            LogEntry::TurnEnd {
+                ts: 200,
+                turn_count: 2,
+            },
+            entry,
+        ]);
+
+        assert_eq!(state.active_run_turn_count, Some(2));
+        assert!(state.last_run_interrupted);
+    }
+
+    #[test]
+    fn non_resumable_interruption_clears_the_active_run_budget() {
+        let state = collect_state(&[
+            LogEntry::Invoke {
+                ts: 100,
+                trigger: InvokeKind::UserSend,
+            },
+            LogEntry::TurnEnd {
+                ts: 200,
+                turn_count: 2,
+            },
+            LogEntry::RunCompleted {
+                ts: 300,
+                interrupted: true,
+                result: EngineResult::LimitReached,
+                active_run_turn_count: None,
+            },
+        ]);
+
+        assert!(state.last_run_interrupted);
+        assert_eq!(state.active_run_turn_count, None);
     }
 
     #[test]

crates/session-store/tests/fs_store_test.rs

@@ -51,6 +51,7 @@ fn round_trip_write_and_read() {
             ts: 3200,
             interrupted: false,
             result: EngineResult::Finished,
+            active_run_turn_count: None,
         },
     ];
 

crates/session-store/tests/session_test.rs

@@ -132,6 +132,7 @@ async fn run_and_persist(
                 segment_id,
                 r.clone(),
                 worker.last_run_interrupted(),
+                worker.active_run_turn_count(),
             )
             .unwrap();
         }
@@ -309,6 +310,7 @@ async fn session_resume_after_pause() {
     // Restore state and verify
     let state = session_store::restore(&store, sid, segid).unwrap();
     assert!(state.last_run_interrupted);
+    assert_eq!(state.active_run_turn_count, Some(2));
 }
 
 #[tokio::test]

crates/worker/src/worker.rs

@@ -781,9 +781,21 @@ struct EmptyTurnRollbackSnapshot {
     usage_history_len: usize,
     ai_activity_count: usize,
     last_run_interrupted: bool,
+    active_run_turn_count: Option<usize>,
     flow_runtime_state: Option<flow::FlowRuntimeState>,
 }
 
+fn active_run_checkpoint_entry(
+    active_run_turn_count: Option<usize>,
+    total_turn_count: usize,
+) -> Option<LogEntry> {
+    active_run_turn_count.map(|active_turn_count| LogEntry::ActiveRunCheckpoint {
+        ts: segment_log::now_millis(),
+        active_turn_count,
+        total_turn_count,
+    })
+}
+
 fn is_ai_materialized_item(item: &Item) -> bool {
     match item {
         Item::Message { role, .. } => *role == Role::Assistant,
@@ -1777,6 +1789,8 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
         self.engine_mut().set_turn_count(state.turn_count);
         self.engine_mut()
             .set_last_run_interrupted(state.last_run_interrupted);
+        self.engine_mut()
+            .set_active_run_turn_count(state.active_run_turn_count);
         self.user_segments = state.user_segments;
         *self.usage_history.lock().expect("usage_history poisoned") = state.usage_history;
         *self
@@ -2350,6 +2364,7 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
             usage_history_len,
             ai_activity_count: self.ai_activity_counter.load(Ordering::SeqCst),
             last_run_interrupted: self.engine().last_run_interrupted(),
+            active_run_turn_count: self.engine().active_run_turn_count(),
             flow_runtime_state: self
                 .flow_runtime_state
                 .lock()
@@ -2381,6 +2396,8 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
         self.engine_mut().truncate_history(snapshot.history_len);
         self.engine_mut()
             .set_last_run_interrupted(snapshot.last_run_interrupted);
+        self.engine_mut()
+            .set_active_run_turn_count(snapshot.active_run_turn_count);
         *self
             .flow_runtime_state
             .lock()
@@ -2541,9 +2558,7 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
         // `last_run_interrupted` flag; `Worker::resume` reuses the prior
         // context via a different entry point and never triggers this
         // path.
-        if self.engine.as_ref().unwrap().last_run_interrupted() {
-            self.apply_interrupt_prep()?;
-        }
+        self.prepare_interrupted_history_for_fresh_run()?;
 
         self.prepare_for_run().await?;
 
@@ -2654,6 +2669,19 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
         out
     }
 
+    /// Close interrupted history before a fresh user/notification run.
+    ///
+    /// Clearing the interrupted flag also ends the old logical-run budget and
+    /// must happen before `prepare_for_run`: proactive compaction checkpoints
+    /// only resumable runs, never the run this invocation is abandoning.
+    fn prepare_interrupted_history_for_fresh_run(&mut self) -> Result<(), WorkerError> {
+        if self.engine().last_run_interrupted() {
+            self.apply_interrupt_prep()?;
+            self.engine_mut().set_last_run_interrupted(false);
+        }
+        Ok(())
+    }
+
     /// Stage the post-interruption cleanup at the front of worker
     /// history: close every unanswered `Item::ToolCall` with a synthetic
     /// `Item::ToolResult` (Anthropic wire-validity), then append a
@@ -2769,12 +2797,7 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
             ),
             "run_for_notification expects a non-UserSend InvokeKind; got {kind:?}"
         );
-        // This is a fresh Invoke, not an explicit resume of the interrupted
-        // turn. Close any dangling tool calls before an auto-run notification
-        // can enter `Engine::resume` and execute them again after a crash.
-        if self.engine.as_ref().unwrap().last_run_interrupted() {
-            self.apply_interrupt_prep()?;
-        }
+        self.prepare_interrupted_history_for_fresh_run()?;
         self.prepare_for_run().await?;
 
         // IDLE → active marker for the buffered notification / worker-event
@@ -2866,15 +2889,23 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
             }),
             compacted_from: None,
         };
+        let mut initial_entries = vec![entry.clone()];
+        if let Some(checkpoint) =
+            active_run_checkpoint_entry(w.active_run_turn_count(), w.turn_count())
+        {
+            initial_entries.push(checkpoint);
+        }
         self.store
-            .create_segment(loc.session_id, fork_segment_id, &[entry.clone()])
+            .create_segment(loc.session_id, fork_segment_id, &initial_entries)
             .map_err(WorkerError::from)?;
         self.segment_state.set_location(SegmentLocation {
             session_id: loc.session_id,
             segment_id: fork_segment_id,
         });
-        self.segment_state.set_entries_written(1);
-        self.sink.reset_with_initial(entry);
+        self.segment_state
+            .set_entries_written(initial_entries.len());
+        self.sink
+            .reset_with_initial_entries(initial_entries.clone());
         if self.scope_allocation.is_some() {
             worker_allocation::update_segment(&self.manifest.worker.name, fork_segment_id)?;
         }
@@ -3218,12 +3249,14 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
         }
 
         let interrupted = self.engine.as_ref().unwrap().last_run_interrupted();
+        let active_run_turn_count = self.engine.as_ref().unwrap().active_run_turn_count();
         match result {
             Ok(r) => {
                 self.commit_entry(LogEntry::RunCompleted {
                     ts: segment_log::now_millis(),
                     interrupted,
                     result: r.clone(),
+                    active_run_turn_count,
                 })?;
             }
             Err(e) => {
@@ -3754,6 +3787,11 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
             }),
         };
         let mut initial_entries = vec![entry.clone()];
+        if let Some(checkpoint) =
+            active_run_checkpoint_entry(w.active_run_turn_count(), source_turn_count)
+        {
+            initial_entries.push(checkpoint);
+        }
         if let Some(flow_state) = self
             .flow_runtime_state
             .lock()
@@ -5179,6 +5217,7 @@ where
         worker.set_request_config(state.config.clone());
         worker.set_turn_count(state.turn_count);
         worker.set_last_run_interrupted(state.last_run_interrupted);
+        worker.set_active_run_turn_count(state.active_run_turn_count);
         if anchored_on_summary {
             worker.set_cache_anchor(Some(0));
         }
@@ -6957,6 +6996,108 @@ mod build_summary_prompt_tests {
         }
     }
 
+    #[tokio::test]
+    async fn fresh_run_clears_interrupted_budget_before_pre_run_compaction() {
+        let dir = tempfile::tempdir().unwrap();
+        let store = session_store::FsStore::new(dir.path().join("sessions")).unwrap();
+        let mut worker = Worker::new(
+            minimal_manifest(),
+            Engine::new(NoopClient),
+            store,
+            WorkerWorkspaceContext::no_workspace(),
+            WorkerFilesystemAuthority::None,
+            Scope::empty(),
+        )
+        .await
+        .unwrap();
+        worker.ensure_segment_head().unwrap();
+        worker.engine_mut().set_last_run_interrupted(true);
+        worker.engine_mut().set_active_run_turn_count(Some(3));
+
+        worker.prepare_interrupted_history_for_fresh_run().unwrap();
+
+        assert!(!worker.engine().last_run_interrupted());
+        assert_eq!(worker.engine().active_run_turn_count(), None);
+        let checkpoint = active_run_checkpoint_entry(
+            worker.engine().active_run_turn_count(),
+            worker.engine().turn_count(),
+        );
+        assert!(checkpoint.is_none());
+
+        let mut replacement_entries = vec![LogEntry::SegmentStart {
+            ts: segment_log::now_millis(),
+            session_id: uuid::Uuid::nil(),
+            system_prompt: None,
+            config: RequestConfig::default(),
+            history: vec![],
+            forked_from: None,
+            compacted_from: None,
+        }];
+        replacement_entries.extend(checkpoint);
+        let restored = session_store::collect_state(&replacement_entries);
+        assert!(!restored.last_run_interrupted);
+        assert_eq!(restored.active_run_turn_count, None);
+    }
+
+    #[tokio::test]
+    async fn auto_fork_checkpoints_interrupted_run_budget_for_restore() {
+        let dir = tempfile::tempdir().unwrap();
+        let store = session_store::FsStore::new(dir.path().join("sessions")).unwrap();
+        let mut worker = Worker::new(
+            minimal_manifest(),
+            Engine::new(NoopClient),
+            store,
+            WorkerWorkspaceContext::no_workspace(),
+            WorkerFilesystemAuthority::None,
+            Scope::empty(),
+        )
+        .await
+        .unwrap();
+        worker.ensure_segment_head().unwrap();
+        worker.engine_mut().set_turn_count(7);
+        worker.engine_mut().set_last_run_interrupted(true);
+        worker.engine_mut().set_active_run_turn_count(Some(3));
+
+        let session_id = worker.session_id();
+        let source_segment_id = worker.segment_id();
+        worker
+            .store()
+            .append(
+                session_id,
+                source_segment_id,
+                &LogEntry::Extension {
+                    ts: segment_log::now_millis(),
+                    domain: "test.auto_fork_drift".into(),
+                    payload: serde_json::json!({}),
+                },
+            )
+            .unwrap();
+
+        worker.ensure_segment_head().unwrap();
+
+        let fork_segment_id = worker.segment_id();
+        assert_ne!(fork_segment_id, source_segment_id);
+        let fork_entries = worker
+            .store()
+            .read_all(session_id, fork_segment_id)
+            .unwrap();
+        assert!(matches!(
+            fork_entries.as_slice(),
+            [
+                LogEntry::SegmentStart { .. },
+                LogEntry::ActiveRunCheckpoint {
+                    active_turn_count: 3,
+                    total_turn_count: 7,
+                    ..
+                }
+            ]
+        ));
+        let restored = session_store::collect_state(&fork_entries);
+        assert!(restored.last_run_interrupted);
+        assert_eq!(restored.turn_count, 7);
+        assert_eq!(restored.active_run_turn_count, Some(3));
+    }
+
     #[tokio::test]
     async fn flow_transition_feature_installs_runtime_local_coordinator() {
         let dir = tempfile::tempdir().unwrap();