Atmos

A minimal, Jotai-inspired state management library for Flutter.
Simple atoms, computed atoms, and fine-grained UI updates — with zero boilerplate.

Warning

Atmos is experimental and under active development. APIs may change, break, or explode spectacularly. Use at your own risk and have fun. 😄

Start with Atom

Atoms are the basic units of state. They hold values or compute values derived from other atoms.

Value Atom

Stores a mutable value managed by the Atmos store.

final counterAtom = atom(0);

Derived (Computed) Atom

Automatically derives its value using other atoms. Recomputes when dependencies change.

final doubledAtom = computed((get) => get(counterAtom) * 2);

AtomBuilder

A Flutter widget that rebuilds when its atom updates. It provides the current value and a setter (for writable atoms).

AtomBuilder(
  atom: counterAtom,
  builder: (context, count, setCount) {
    return TextButton(
      onPressed: () => setCount(count + 1),
      child: Text('Count: $count'),
    );
  },
);

You can read computed atoms exactly the same way.

AtomBuilder(
  atom: doubledAtom,
  builder: (_, value, __) => Text('Doubled: $value'),
);

Important

Computed atoms cannot be written to — setValue is a no-op.

The AtmosStore API

Atmos ships with a global store you rarely need to interact with directly.

final store = AtmosStore.instance;

// Read
store.read(counterAtom);

// Write
store.write(counterAtom, 42);

// Subscribe
store.subscribe(counterAtom, () => print('counter changed!'));

// Unsubscribe
store.unsubscribe(counterAtom, () {});

License

The project is released under the MIT License. Learn more about it, here.