### When NOT to Use computed()

**Within JSX, reactivity is automatic—you don't need `computed()`:**

```tsx
import { computed, UI, pattern } from 'commontools';

interface Input {
  userName: string;
  user: { name: string };
}

export default pattern<Input>(({ userName, user }) => {
  return {
    [UI]: (
      <>
        {/* ❌ Don't use computed() in JSX */}
        <div>
          {computed(() => `Hello, ${userName}`)}  {/* Unnecessary! */}
        </div>

        {/* ✅ Just reference directly */}
        <div>
          Hello, {userName}
        </div>

        {/* ❌ Don't use computed() for simple property access */}
        <div>
          {computed(() => user.name)}  {/* Unnecessary! */}
        </div>

        {/* ✅ Direct access works fine */}
        <div>
          {user.name}
        </div>
      </>
    ),
  };
});
```