diff --git a/dashboard/src/__tests__/TTLSelector.test.tsx b/dashboard/src/__tests__/TTLSelector.test.tsx
new file mode 100644
index 00000000..8ed741a7
--- /dev/null
+++ b/dashboard/src/__tests__/TTLSelector.test.tsx
@@ -0,0 +1,114 @@
+import { describe, it, expect, vi } from 'vitest';
+import { render, screen, fireEvent } from '@testing-library/react';
+import { TTLSelector } from '../components/TTLSelector';
+
+describe('TTLSelector', () => {
+  const mockOnChange = vi.fn();
+
+  it('renders preset buttons', () => {
+    const {} = render(
+      <TTLSelector value={undefined} onChange={mockOnChange} />,
+    );
+
+    expect(screen.getByRole('button', { name: '15m' })).toBeDefined();
+    expect(screen.getByRole('button', { name: '1h' })).toBeDefined();
+    expect(screen.getByRole('button', { name: '4h' })).toBeDefined();
+    expect(screen.getByRole('button', { name: '8h' })).toBeDefined();
+  });
+
+  it('highlights the selected preset', () => {
+    const {} = render(
+      <TTLSelector value={15 * 60} onChange={mockOnChange} />,
+    );
+
+    const btn15m = screen.getByRole('button', { name: '15m' }) as HTMLButtonElement;
+    expect(btn15m.className).toContain('bg-[#00e5ff]/10');
+    expect(btn15m.className).toContain('text-[#00e5ff]');
+  });
+
+  it('calls onChange when a preset is clicked', () => {
+    const onChange = vi.fn();
+    render(<TTLSelector value={undefined} onChange={onChange} />);
+
+    const btn1h = screen.getByRole('button', { name: '1h' });
+    fireEvent.click(btn1h);
+
+    expect(onChange).toHaveBeenCalledWith(60 * 60);
+  });
+
+  it('allows custom duration entry', () => {
+    const onChange = vi.fn();
+    render(<TTLSelector value={undefined} onChange={onChange} />);
+
+    const input = screen.getByPlaceholderText('Custom minutes…') as HTMLInputElement;
+    fireEvent.change(input, { target: { value: '30' } });
+
+    expect(onChange).toHaveBeenCalledWith(30 * 60);
+  });
+
+  it('displays formatted duration for custom input', () => {
+    render(<TTLSelector value={undefined} onChange={vi.fn()} />);
+
+    const input = screen.getByPlaceholderText('Custom minutes…') as HTMLInputElement;
+    fireEvent.change(input, { target: { value: '90' } });
+
+    expect(screen.getByText('1h 30m')).toBeDefined();
+  });
+
+  it('displays current TTL value', () => {
+    render(<TTLSelector value={4 * 60 * 60} onChange={vi.fn()} />);
+
+    expect(screen.getByText(/TTL: 4h/)).toBeDefined();
+  });
+
+  it('clears custom input when preset is clicked', () => {
+    const onChange = vi.fn();
+    const { rerender } = render(
+      <TTLSelector value={undefined} onChange={onChange} />,
+    );
+
+    const input = screen.getByPlaceholderText('Custom minutes…') as HTMLInputElement;
+    fireEvent.change(input, { target: { value: '30' } });
+    expect(input.value).toBe('30');
+
+    const btn1h = screen.getByRole('button', { name: '1h' });
+    fireEvent.click(btn1h);
+
+    rerender(<TTLSelector value={60 * 60} onChange={onChange} />);
+    expect(input.value).toBe('');
+  });
+
+  it('clears TTL when custom input is emptied', () => {
+    const onChange = vi.fn();
+    render(<TTLSelector value={undefined} onChange={onChange} />);
+
+    const input = screen.getByPlaceholderText('Custom minutes…') as HTMLInputElement;
+    fireEvent.change(input, { target: { value: '30' } });
+    expect(onChange).toHaveBeenCalledWith(30 * 60);
+
+    fireEvent.change(input, { target: { value: '' } });
+    expect(onChange).toHaveBeenCalledWith(undefined);
+  });
+
+  it('ignores invalid custom input', () => {
+    const onChange = vi.fn();
+    render(<TTLSelector value={undefined} onChange={onChange} />);
+
+    const input = screen.getByPlaceholderText('Custom minutes…') as HTMLInputElement;
+    fireEvent.change(input, { target: { value: 'invalid' } });
+
+    // onChange should not be called with invalid input
+    expect(onChange).not.toHaveBeenCalledWith(expect.any(Number));
+  });
+
+  it('shows custom value as selected when value is not a preset', () => {
+    render(<TTLSelector value={37 * 60} onChange={vi.fn()} />);
+
+    // Should show the custom input with the value
+    const input = screen.getByPlaceholderText('Custom minutes…') as HTMLInputElement;
+    expect(input.value).toBe('37');
+
+    // Should display the formatted duration
+    expect(screen.getByText('37m')).toBeDefined();
+  });
+});
diff --git a/dashboard/src/components/CreateSessionModal.tsx b/dashboard/src/components/CreateSessionModal.tsx
index e6ea3e9a..bbc7e77d 100644
--- a/dashboard/src/components/CreateSessionModal.tsx
+++ b/dashboard/src/components/CreateSessionModal.tsx
@@ -6,6 +6,7 @@ import { useState, useEffect, useRef, useCallback } from 'react';
 import { useNavigate } from 'react-router-dom';
 import { X, Loader2, Plus, Trash2 } from 'lucide-react';
 import { createSession, batchCreateSessions } from '../api/client';
+import { TTLSelector } from './TTLSelector';
 
 interface CreateSessionModalProps {
   open: boolean;
@@ -86,12 +87,14 @@ export default function CreateSessionModal({ open, onClose }: CreateSessionModal
   const [name, setName] = useState('');
   const [prompt, setPrompt] = useState('');
   const [permissionMode, setPermissionMode] = useState('default');
+  const [ttl, setTtl] = useState<number | undefined>(undefined);
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState<string | null>(null);
 
   const [mode, setMode] = useState<'single' | 'batch'>('single');
   const [batchRows, setBatchRows] = useState<BatchRow[]>([makeRow(), makeRow()]);
   const [sharedPrompt, setSharedPrompt] = useState('');
+  const [batchTtl, setBatchTtl] = useState<number | undefined>(undefined);
   const [batchResult, setBatchResult] = useState<{
     sessions: Array<{ id: string; name: string }>;
     created: number;
@@ -104,10 +107,12 @@ export default function CreateSessionModal({ open, onClose }: CreateSessionModal
     setName('');
     setPrompt('');
     setPermissionMode('default');
+    setTtl(undefined);
     setLoading(false);
     setError(null);
     setBatchRows([makeRow(), makeRow()]);
     setSharedPrompt('');
+    setBatchTtl(undefined);
     setBatchResult(null);
     setMode('single');
   }
@@ -149,6 +154,7 @@ export default function CreateSessionModal({ open, onClose }: CreateSessionModal
           name: row.name.trim() || undefined,
           prompt: (row.prompt.trim() || sharedPrompt.trim()) || undefined,
           permissionMode,
+          ttl_seconds: batchTtl,
         })),
         signal: controller.signal,
       });
@@ -185,6 +191,7 @@ export default function CreateSessionModal({ open, onClose }: CreateSessionModal
         name: name.trim() || undefined,
         prompt: prompt.trim() || undefined,
         permissionMode,
+        ttl_seconds: ttl,
         signal: controller.signal,
       });
       resetForm();
@@ -312,6 +319,9 @@ export default function CreateSessionModal({ open, onClose }: CreateSessionModal
             </select>
           </div>
 
+          {/* TTL */}
+          <TTLSelector value={ttl} onChange={setTtl} />
+
           {/* Error */}
           {error && (
             <div className="text-xs text-[#ff3366] bg-[#ff3366]/10 border border-[#ff3366]/20 rounded px-3 py-2">
@@ -432,6 +442,9 @@ export default function CreateSessionModal({ open, onClose }: CreateSessionModal
             </select>
           </div>
 
+          {/* TTL */}
+          <TTLSelector value={batchTtl} onChange={setBatchTtl} />
+
           {/* Error */}
           {error && (
             <div className="text-xs text-[#ff3366] bg-[#ff3366]/10 border border-[#ff3366]/20 rounded px-3 py-2">
diff --git a/dashboard/src/components/TTLSelector.tsx b/dashboard/src/components/TTLSelector.tsx
new file mode 100644
index 00000000..140a3c0b
--- /dev/null
+++ b/dashboard/src/components/TTLSelector.tsx
@@ -0,0 +1,110 @@
+/**
+ * components/TTLSelector.tsx — Time-to-live selector component.
+ * 
+ * Allows users to select session TTL with presets (15m, 1h, 4h, 8h) or custom duration.
+ */
+
+import { useState } from 'react';
+import { Clock } from 'lucide-react';
+
+interface TTLSelectorProps {
+  /** Selected TTL in seconds. undefined = no TTL set. */
+  value: number | undefined;
+  /** Callback when TTL is changed. */
+  onChange: (ttl: number | undefined) => void;
+}
+
+const TTL_PRESETS = [
+  { label: '15m', seconds: 15 * 60 },
+  { label: '1h', seconds: 60 * 60 },
+  { label: '4h', seconds: 4 * 60 * 60 },
+  { label: '8h', seconds: 8 * 60 * 60 },
+] as const;
+
+export function TTLSelector({ value, onChange }: TTLSelectorProps) {
+  // Track whether we're in custom mode (value is not one of the presets)
+  const isCustom = value !== undefined && !TTL_PRESETS.some(p => p.seconds === value);
+  const [customInput, setCustomInput] = useState<string>(
+    isCustom ? String(Math.floor((value ?? 0) / 60)) : ''
+  );
+
+  function handlePresetClick(seconds: number) {
+    onChange(seconds);
+    setCustomInput('');
+  }
+
+  function handleCustomChange(e: React.ChangeEvent<HTMLInputElement>) {
+    const input = e.target.value;
+    setCustomInput(input);
+    
+    if (!input.trim()) {
+      onChange(undefined);
+    } else {
+      const minutes = parseInt(input, 10);
+      if (!isNaN(minutes) && minutes > 0) {
+        onChange(minutes * 60);
+      }
+    }
+  }
+
+  return (
+    <div className="space-y-3">
+      <div className="flex items-center gap-2">
+        <Clock className="h-4 w-4 text-gray-500" />
+        <label className="block text-xs font-medium text-gray-400">
+          Session TTL <span className="text-gray-600">(optional)</span>
+        </label>
+      </div>
+
+      {/* Preset buttons */}
+      <div className="grid grid-cols-4 gap-2">
+        {TTL_PRESETS.map((preset) => (
+          <button
+            key={preset.label}
+            type="button"
+            onClick={() => handlePresetClick(preset.seconds)}
+            className={`py-2 px-2 text-xs rounded transition-colors border ${
+              value === preset.seconds
+                ? 'bg-[#00e5ff]/10 border-[#00e5ff] text-[#00e5ff]'
+                : 'border-[#1a1a2e] text-gray-400 hover:text-gray-300 hover:border-[#2a2a3e]'
+            }`}
+          >
+            {preset.label}
+          </button>
+        ))}
+      </div>
+
+      {/* Custom input */}
+      <div>
+        <input
+          type="number"
+          value={customInput}
+          onChange={handleCustomChange}
+          placeholder="Custom minutes…"
+          min="1"
+          className="w-full min-h-[44px] px-3 py-2.5 text-sm bg-[#0a0a0f] border border-[#1a1a2e] rounded text-gray-200 placeholder-gray-600 focus:outline-none focus:border-[#00e5ff]"
+        />
+        {customInput && !isNaN(parseInt(customInput, 10)) && (
+          <p className="text-xs text-gray-500 mt-1">
+            {formatDuration(parseInt(customInput, 10) * 60)}
+          </p>
+        )}
+      </div>
+
+      {/* Current value display */}
+      {value !== undefined && (
+        <p className="text-xs text-gray-500">
+          TTL: {formatDuration(value)}
+        </p>
+      )}
+    </div>
+  );
+}
+
+function formatDuration(seconds: number): string {
+  if (seconds < 60) return `${seconds}s`;
+  if (seconds < 3600) return `${Math.floor(seconds / 60)}m`;
+  const hours = Math.floor(seconds / 3600);
+  const mins = Math.floor((seconds % 3600) / 60);
+  return mins > 0 ? `${hours}h ${mins}m` : `${hours}h`;
+}
diff --git a/dashboard/src/types/index.ts b/dashboard/src/types/index.ts
index 6ef0c58b..18e897c9 100644
--- a/dashboard/src/types/index.ts
+++ b/dashboard/src/types/index.ts
@@ -220,6 +220,7 @@ export interface CreateSessionRequest {
   permissionMode?: string;
   /** @deprecated Use permissionMode. */
   autoApprove?: boolean;
+  ttl_seconds?: number;
 }
 
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