diff --git a/AGENTS.md b/AGENTS.md
index 93066114..3d01994d 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -115,7 +115,7 @@ npm run test:vitest -- ...  # Repo-owned direct Vitest path for focused passthro
 
 **WebSocket Protocol:** Schema-validated messages using Zod. Handshake flow: client sends `hello` with token → server validates → sends `ready`. Message types include `terminal.create/input/resize/detach/attach` and broadcasts like `sessions.updated`.
 
-**PTY Lifecycle:** Each terminal has a unique ID. Server maintains 64KB scrollback buffer. On attach, client receives buffer snapshot then streams new output. On detach, process continues running (background session). Configurable idle timeout (180 mins default).
+**PTY Lifecycle:** Each terminal has a unique ID. Server maintains 64KB scrollback buffer. On attach, client receives buffer snapshot then streams new output. On detach, process continues running (background session). Configurable idle timeout (15 mins default).
 
 **Claude Session Discovery:** Watches `~/.claude/projects/*/sessions/*.jsonl` for new files. Parses JSONL streams to extract messages, groups by project path.
 
diff --git a/shared/settings.ts b/shared/settings.ts
index ee1f3435..9608eced 100644
--- a/shared/settings.ts
+++ b/shared/settings.ts
@@ -725,7 +725,7 @@ export function createDefaultServerSettings(options: SettingsDefaultsOptions = {
       debug: options.loggingDebug ?? false,
     },
     safety: {
-      autoKillIdleMinutes: 180,
+      autoKillIdleMinutes: 15,
     },
     terminal: {
       scrollback: 10000,
diff --git a/src/components/settings/SafetySettings.tsx b/src/components/settings/SafetySettings.tsx
index 4c49aa08..8cdc4e41 100644
--- a/src/components/settings/SafetySettings.tsx
+++ b/src/components/settings/SafetySettings.tsx
@@ -498,9 +498,9 @@ export default function SafetySettings({
         <SettingsRow label="Auto-kill idle (minutes)">
           <RangeSlider
             value={settings.safety.autoKillIdleMinutes}
-            min={10}
+            min={5}
             max={720}
-            step={10}
+            step={5}
             format={(v) => String(v)}
             onChange={(v) => {
               applyServerSetting({ safety: { autoKillIdleMinutes: v } })
diff --git a/test/unit/client/components/SettingsView.behavior.test.tsx b/test/unit/client/components/SettingsView.behavior.test.tsx
index e267187e..90824299 100644
--- a/test/unit/client/components/SettingsView.behavior.test.tsx
+++ b/test/unit/client/components/SettingsView.behavior.test.tsx
@@ -327,7 +327,7 @@ describe('SettingsView behavior sections', () => {
       const autoKillSlider = getSlider((slider) => {
         const min = slider.getAttribute('min')
         const max = slider.getAttribute('max')
-        return min === '10' && max === '720'
+        return min === '5' && max === '720'
       })
 
       fireEvent.change(autoKillSlider, { target: { value: '300' } })
diff --git a/test/unit/shared/settings.test.ts b/test/unit/shared/settings.test.ts
index 96f63fe5..f213efcd 100644
--- a/test/unit/shared/settings.test.ts
+++ b/test/unit/shared/settings.test.ts
@@ -176,6 +176,7 @@ describe('shared settings contract', () => {
 
     expect(resolved.terminal.fontFamily).toBe('Fira Code')
     expect(resolved.terminal.scrollback).toBe(10000)
+    expect(resolved.safety.autoKillIdleMinutes).toBe(15)
     expect(resolved.sidebar.sortMode).toBe('project')
     expect(resolved.agentChat.defaultPlugins).toEqual([])
   })