back_stack
You own the back stack. Navigation is a List you push and pop — type-safe,
observable, no route graph.
back_stack brings Jetpack Compose Navigation 3's "you own the back stack"
model to Flutter. Destinations are plain Dart types, checked by the compiler,
and the UI just renders the list.
// Destinations are typed objects — arguments are real, checked fields.
abstract class AppKey extends NavKey { const AppKey(); }
class Home extends AppKey { const Home(); }
class Product extends AppKey { const Product(this.id); final int id; }
// One line per screen.
final entries = NavEntries<AppKey>()
..on<Home>((context, key) => const HomeScreen())
..on<Product>((context, key) => ProductScreen(id: key.id));
// The back stack is a list you own.
final stack = NavStack<AppKey>.of(const Home());
void main() => runApp(BackStackApp<AppKey>(stack: stack, entries: entries));
That's a complete app. Navigate by changing the list — from anywhere:
stack.push(const Product(42)); // forward
stack.pop(); // back
stack.replaceAll([const Home()]); // reset a flow (e.g. after login)
System back, predictive back, and the hardware button already flow into the
list. Everything else is one parameter on BackStackApp — the wiring is
internal:
| You want | You pass |
|---|
| Deep links, web URLs, shareable links | links: — one NavLinks table |
| Restoration across process death | already on with links: — see Restoration |
| Async link resolution ("does this doc exist?") | onLinkAsync: |
Links from a native plugin (app_links) | initialLink: / linkStream: |
| Persistent chrome around the navigator | shell: |
| Bottom tabs with per-tab history | the sibling widget, BackStackTabsApp |
And because the stack is plain data, testing is stack.push(...) then
expect(stack.keys, [...]) — no harness, no mocks.
Next