fix(kernel): avoid crashing idle reactive agents

crates/openfang-api/src/routes.rs

@@ -8030,7 +8030,9 @@ fn build_skill_config_snapshot(
             .read()
             .unwrap_or_else(|e| e.into_inner());
         let source: &std::collections::HashMap<String, std::collections::HashMap<String, String>> =
-            override_guard.as_ref().unwrap_or(&state.kernel.config.skills);
+            override_guard
+                .as_ref()
+                .unwrap_or(&state.kernel.config.skills);
         source.get(skill_name).cloned().unwrap_or_default()
     };
 
@@ -8392,7 +8394,9 @@ fn remove_skill_config_var(
 
     let mut remove_skill = false;
     if let Some(skills_table) = root.get_mut("skills").and_then(|v| v.as_table_mut()) {
-        if let Some(skill_section) = skills_table.get_mut(skill_name).and_then(|v| v.as_table_mut())
+        if let Some(skill_section) = skills_table
+            .get_mut(skill_name)
+            .and_then(|v| v.as_table_mut())
         {
             skill_section.remove(var_name);
             if skill_section.is_empty() {
@@ -9019,9 +9023,8 @@ pub async fn create_schedule(
     }
     if let Some(arr) = delivery_targets_raw.as_array() {
         for (idx, t) in arr.iter().enumerate() {
-            if let Err(e) = serde_json::from_value::<
-                openfang_types::scheduler::CronDeliveryTarget,
-            >(t.clone())
+            if let Err(e) =
+                serde_json::from_value::<openfang_types::scheduler::CronDeliveryTarget>(t.clone())
             {
                 return (
                     StatusCode::BAD_REQUEST,
@@ -9152,9 +9155,8 @@ pub async fn update_schedule(
         let mut parsed: Vec<openfang_types::scheduler::CronDeliveryTarget> =
             Vec::with_capacity(arr.len());
         for (idx, t) in arr.iter().enumerate() {
-            match serde_json::from_value::<openfang_types::scheduler::CronDeliveryTarget>(
-                t.clone(),
-            ) {
+            match serde_json::from_value::<openfang_types::scheduler::CronDeliveryTarget>(t.clone())
+            {
                 Ok(dt) => parsed.push(dt),
                 Err(e) => {
                     return (

crates/openfang-api/tests/api_integration_test.rs

@@ -1156,7 +1156,10 @@ async fn test_commands_invalid_surface_400() {
     assert_eq!(resp.status(), 400);
     let body: serde_json::Value = resp.json().await.unwrap();
     let err = body["error"].as_str().unwrap_or_default();
-    assert!(err.contains("bogus"), "error should mention the bad value: {err}");
+    assert!(
+        err.contains("bogus"),
+        "error should mention the bad value: {err}"
+    );
 }
 
 // ---------------------------------------------------------------------------
@@ -1211,7 +1214,10 @@ async fn test_schedules_delivery_targets_roundtrip() {
         .unwrap();
     assert_eq!(resp.status(), 201);
     let body: serde_json::Value = resp.json().await.unwrap();
-    let sched_id = body["id"].as_str().expect("created schedule id").to_string();
+    let sched_id = body["id"]
+        .as_str()
+        .expect("created schedule id")
+        .to_string();
     let got = body["delivery_targets"]
         .as_array()
         .expect("response must include delivery_targets");
@@ -1291,7 +1297,9 @@ async fn test_schedules_delivery_targets_update() {
     let body: serde_json::Value = resp.json().await.unwrap();
     assert_eq!(body["status"], "updated");
     let echoed = &body["schedule"]["delivery_targets"];
-    let arr = echoed.as_array().expect("schedule.delivery_targets must be array");
+    let arr = echoed
+        .as_array()
+        .expect("schedule.delivery_targets must be array");
     assert_eq!(arr.len(), 2);
     assert_eq!(arr[0]["type"], "webhook");
     assert_eq!(arr[1]["type"], "local_file");
@@ -1406,10 +1414,7 @@ async fn test_schedules_delivery_log_endpoint() {
         .await
         .unwrap();
     assert_eq!(resp.status(), 201);
-    let sched_id = resp
-        .json::<serde_json::Value>()
-        .await
-        .unwrap()["id"]
+    let sched_id = resp.json::<serde_json::Value>().await.unwrap()["id"]
         .as_str()
         .unwrap()
         .to_string();

crates/openfang-api/tests/skill_config_api_test.rs

@@ -166,7 +166,9 @@ async fn get_config_returns_declared_and_resolved() {
         body["resolved"]["github_token"]["source"], "unresolved",
         "github_token should be unresolved without env"
     );
-    assert!(body["resolved"]["github_token"]["is_secret"].as_bool().unwrap());
+    assert!(body["resolved"]["github_token"]["is_secret"]
+        .as_bool()
+        .unwrap());
 
     // default_branch falls back to default "main".
     assert_eq!(body["resolved"]["default_branch"]["source"], "default");
@@ -255,10 +257,7 @@ async fn put_rejects_unknown_variable() {
         .unwrap();
     assert_eq!(resp.status(), 400);
     let body: serde_json::Value = resp.json().await.unwrap();
-    assert!(body["error"]
-        .as_str()
-        .unwrap()
-        .contains("nonexistent_var"));
+    assert!(body["error"].as_str().unwrap().contains("nonexistent_var"));
 }
 
 #[tokio::test]
@@ -377,12 +376,7 @@ async fn put_reloads_registry_so_agents_see_change() {
         .unwrap();
 
     // The kernel's live override map must now hold the new values.
-    let guard = server
-        .state
-        .kernel
-        .skill_config_overrides
-        .read()
-        .unwrap();
+    let guard = server.state.kernel.skill_config_overrides.read().unwrap();
     let overrides = guard.as_ref().expect("override map set after PUT");
     let skill_cfg = overrides.get("test-config-skill").expect("skill present");
     assert_eq!(skill_cfg.get("github_token").unwrap(), "ghp_new");

crates/openfang-cli/src/tui/mod.rs

@@ -2023,10 +2023,8 @@ impl App {
         match canonical_head.as_str() {
             "/exit" => self.handle_chat_action(chat::ChatAction::Back),
             "/help" => {
-                self.chat.push_message(
-                    chat::Role::System,
-                    commands::render_help(Surfaces::CLI),
-                );
+                self.chat
+                    .push_message(chat::Role::System, commands::render_help(Surfaces::CLI));
             }
             "/status" => {
                 let mut s = Vec::new();

crates/openfang-cli/src/tui/screens/skills.rs

@@ -219,8 +219,7 @@ impl SkillsState {
                         if self.installed[sel].config_declared > 0 {
                             return SkillsAction::LoadSkillConfig(name);
                         } else {
-                            self.status_msg =
-                                format!("'{}' declares no runtime config.", name);
+                            self.status_msg = format!("'{}' declares no runtime config.", name);
                         }
                     }
                 }
@@ -531,10 +530,7 @@ fn draw_skill_config_details(f: &mut Frame, area: Rect, state: &SkillsState) {
 
     if rows.is_empty() {
         f.render_widget(
-            Paragraph::new(Span::styled(
-                "No config declared.",
-                theme::dim_style(),
-            )),
+            Paragraph::new(Span::styled("No config declared.", theme::dim_style())),
             inner,
         );
         return;

crates/openfang-kernel/src/cron_delivery.rs

@@ -436,7 +436,9 @@ mod tests {
             auth_header: Some("Bearer test-token".to_string()),
         };
         let engine = test_engine(MockBridge::new());
-        let results = engine.deliver(&[target], "daily-report", "result body").await;
+        let results = engine
+            .deliver(&[target], "daily-report", "result body")
+            .await;
 
         assert!(results[0].success, "error: {:?}", results[0].error);
 
@@ -732,8 +734,6 @@ mod tests {
     }
 
     fn find_subsequence(haystack: &[u8], needle: &[u8]) -> Option<usize> {
-        haystack
-            .windows(needle.len())
-            .position(|w| w == needle)
+        haystack.windows(needle.len()).position(|w| w == needle)
     }
 }

crates/openfang-kernel/src/heartbeat.rs

@@ -12,7 +12,7 @@
 use crate::registry::AgentRegistry;
 use chrono::Utc;
 use dashmap::DashMap;
-use openfang_types::agent::{AgentId, AgentState};
+use openfang_types::agent::{AgentEntry, AgentId, AgentState, ScheduleMode};
 use tracing::{debug, warn};
 
 /// Default heartbeat check interval (seconds).
@@ -132,6 +132,14 @@ impl Default for RecoveryTracker {
 /// and the initial `set_state(Running)` call.
 const IDLE_GRACE_SECS: i64 = 10;
 
+/// Reactive agents are healthy while idle between user messages.
+///
+/// They should only participate in heartbeat failure detection while a turn is
+/// actively running. Otherwise silence is the expected steady state.
+pub(crate) fn should_exempt_idle_reactive_agent(entry: &AgentEntry, is_running_task: bool) -> bool {
+    matches!(entry.manifest.schedule, ScheduleMode::Reactive) && !is_running_task
+}
+
 /// Check all running and crashed agents and return their heartbeat status.
 ///
 /// This is a pure function — it doesn't start a background task.
@@ -376,6 +384,35 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_idle_reactive_agent_is_exempt_when_not_processing() {
+        let mut agent = make_entry(
+            "reactive-idle",
+            AgentState::Running,
+            Utc::now() - Duration::seconds(600),
+            Utc::now() - Duration::seconds(300),
+        );
+        agent.manifest.schedule = ScheduleMode::Reactive;
+
+        assert!(should_exempt_idle_reactive_agent(&agent, false));
+        assert!(!should_exempt_idle_reactive_agent(&agent, true));
+    }
+
+    #[test]
+    fn test_periodic_agent_is_not_exempt_when_idle() {
+        let mut agent = make_entry(
+            "periodic-idle",
+            AgentState::Running,
+            Utc::now() - Duration::seconds(600),
+            Utc::now() - Duration::seconds(300),
+        );
+        agent.manifest.schedule = ScheduleMode::Periodic {
+            cron: "0 * * * *".to_string(),
+        };
+
+        assert!(!should_exempt_idle_reactive_agent(&agent, false));
+    }
+
     #[test]
     fn test_active_agent_detected_unresponsive() {
         // An agent that WAS active (last_active >> created_at) but has gone

crates/openfang-kernel/src/kernel.rs

@@ -4481,7 +4481,10 @@ impl OpenFangKernel {
     /// Periodically checks all running agents' last_active timestamps and
     /// publishes `HealthCheckFailed` events for unresponsive agents.
     fn start_heartbeat_monitor(self: &Arc<Self>) {
-        use crate::heartbeat::{check_agents, is_quiet_hours, HeartbeatConfig, RecoveryTracker};
+        use crate::heartbeat::{
+            check_agents, is_quiet_hours, should_exempt_idle_reactive_agent, HeartbeatConfig,
+            RecoveryTracker,
+        };
 
         let kernel = Arc::clone(self);
         let config = HeartbeatConfig {
@@ -4505,13 +4508,31 @@ impl OpenFangKernel {
 
                 let statuses = check_agents(&kernel.registry, &config);
                 for status in &statuses {
+                    let Some(entry) = kernel.registry.get(status.agent_id) else {
+                        continue;
+                    };
+
+                    // Reactive agents are expected to be silent while idle.
+                    // Keep them in Running instead of treating normal quiet time
+                    // as a crash unless a turn is actively executing.
+                    if should_exempt_idle_reactive_agent(
+                        &entry,
+                        kernel.running_tasks.contains_key(&status.agent_id),
+                    ) {
+                        if entry.state == AgentState::Crashed {
+                            let _ = kernel
+                                .registry
+                                .set_state(status.agent_id, AgentState::Running);
+                        }
+                        recovery_tracker.reset(status.agent_id);
+                        continue;
+                    }
+
                     // Skip agents in quiet hours (per-agent config)
-                    if let Some(entry) = kernel.registry.get(status.agent_id) {
-                        if let Some(ref auto_cfg) = entry.manifest.autonomous {
-                            if let Some(ref qh) = auto_cfg.quiet_hours {
-                                if is_quiet_hours(qh) {
-                                    continue;
-                                }
+                    if let Some(ref auto_cfg) = entry.manifest.autonomous {
+                        if let Some(ref qh) = auto_cfg.quiet_hours {
+                            if is_quiet_hours(qh) {
+                                continue;
                             }
                         }
                     }
@@ -6383,11 +6404,7 @@ struct KernelCronBridge {
 
 #[async_trait]
 impl openfang_channels::bridge::ChannelBridgeHandle for KernelCronBridge {
-    async fn send_message(
-        &self,
-        _agent_id: AgentId,
-        _message: &str,
-    ) -> Result<String, String> {
+    async fn send_message(&self, _agent_id: AgentId, _message: &str) -> Result<String, String> {
         Err("KernelCronBridge only supports send_channel_message".to_string())
     }
 

crates/openfang-skills/src/config_injection.rs

@@ -154,8 +154,7 @@ pub fn render_config_block(resolved: &HashMap<String, String>) -> String {
     let mut keys: Vec<&String> = resolved.keys().collect();
     keys.sort();
 
-    let mut out =
-        String::from("[Skill config from ~/.openfang/config.toml:\n");
+    let mut out = String::from("[Skill config from ~/.openfang/config.toml:\n");
     for key in keys {
         let raw = &resolved[key];
         let shown = redact_value(key, raw);