# @xstate/fsm

> XState for finite state machines

Latest version **2.1.0** (published 2023-06-21) · MIT license · 0 weekly downloads

## Install

```sh
npm install @xstate/fsm
pnpm add @xstate/fsm
yarn add @xstate/fsm
bun add @xstate/fsm
```

## Health

**Score 50/100 (C)** — status: abandoned.

Positive: has types; esm support; no vulnerabilities; high maintenance score; high quality score; popular repo.

Warnings: low downloads.

Negative: abandoned.

## Facts

| | |
|---|---|
| Version | 2.1.0 |
| Published | 2023-06-21 |
| First published | 2019-05-12 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 0 |
| Unpacked size | 55.8 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 30097 |
| Author | David Khourshid |
| Maintainers | xstate-release-bot, andarist, davidkpiano |
| Keywords | state, machine, scxml, state, machine, finite, state, machine, fsm, automata |

## Links

- npm: https://www.npmjs.com/package/@xstate/fsm
- Repository: https://github.com/statelyai/xstate
- Homepage: https://github.com/statelyai/xstate/tree/main/packages/xstate-fsm#readme
- Issues: https://github.com/statelyai/xstate/issues
- npm.io page: https://npm.io/package/@xstate/fsm

## Alternatives

- [@reckona/mreact-store](https://npm.io/package/@reckona/mreact-store.md) — 976 weekly downloads
- [regular-state](https://npm.io/package/regular-state.md) — 410 weekly downloads
- [@pacote/flux-actions](https://npm.io/package/@pacote/flux-actions.md) — 65 weekly downloads
- [@pilotlab/lux-debug](https://npm.io/package/@pilotlab/lux-debug.md) — 39 weekly downloads
- [vue-persist-state](https://npm.io/package/vue-persist-state.md) — 19 weekly downloads

## Recent versions

- 2.1.0 (latest) — 2023-06-21
- 3.0.0-beta.3 (beta) — 2023-07-11
- 3.0.0-alpha.1 (alpha) — 2023-04-07
- 2.0.1 — 2023-06-06
- 3.0.0-beta.2 — 2023-04-09
- 3.0.0-alpha.0 — 2023-01-07
- 2.0.0 — 2022-04-08
- 1.6.5 — 2022-02-22
- 1.6.4 — 2022-01-27
- 1.6.3 — 2021-12-30
- 1.6.2 — 2021-09-03
- 1.6.1 — 2021-05-17
- 1.6.0 — 2021-02-05
- 1.5.2 — 2020-11-26
- 1.5.1 — 2020-08-27
- … 13 more at https://npm.io/package/@xstate/fsm/versions

## README

# @xstate/fsm

<p align="center">
  <a href="https://xstate.js.org">
  <br />
  <img src="https://i.imgur.com/j4x2zzX.png" alt="XState FSM" width="200"/>
  <br />
    <sub><strong>XState for Finite State Machines</strong></sub>
  <br />
  <br />
  </a>
</p>

This package contains a minimal, 1kb implementation of [XState](https://github.com/statelyai/xstate) for **finite state machines**.

- [Read the full documentation in the XState docs](https://xstate.js.org/docs/packages/xstate-fsm/).
- [Read our contribution guidelines](https://github.com/statelyai/xstate/blob/main/CONTRIBUTING.md).

## Features

|                             | **@xstate/fsm** | [XState](https://github.com/statelyai/xstate) |
| --------------------------- | :-------------: | :-------------------------------------------: |
| Finite states               |       ✅        |                      ✅                       |
| Initial state               |       ✅        |                      ✅                       |
| Transitions (object)        |       ✅        |                      ✅                       |
| Transitions (string target) |       ✅        |                      ✅                       |
| Delayed transitions         |       ❌        |                      ✅                       |
| Eventless transitions       |       ❌        |                      ✅                       |
| Wildcard transitions        |       ✅        |                      ✅                       |
| Nested states               |       ❌        |                      ✅                       |
| Parallel states             |       ❌        |                      ✅                       |
| History states              |       ❌        |                      ✅                       |
| Final states                |       ❌        |                      ✅                       |
| Context                     |       ✅        |                      ✅                       |
| Entry actions               |       ✅        |                      ✅                       |
| Exit actions                |       ✅        |                      ✅                       |
| Transition actions          |       ✅        |                      ✅                       |
| Parameterized actions       |       ❌        |                      ✅                       |
| Transition guards           |       ✅        |                      ✅                       |
| Parameterized guards        |       ❌        |                      ✅                       |
| Spawned actors              |       ❌        |                      ✅                       |
| Invoked actors              |       ❌        |                      ✅                       |

- Finite states (non-nested)
- Initial state
- Transitions (object or strings)
- Context
- Entry actions
- Exit actions
- Transition actions
- `state.changed`

If you want to use statechart features such as nested states, parallel states, history states, activities, invoked services, delayed transitions, transient transitions, etc. please use [`XState`](https://github.com/statelyai/xstate).

## Quick start

### Installation

```bash
npm i @xstate/fsm
```

### Usage (machine)

```js
import { createMachine } from '@xstate/fsm';

const toggleMachine = createMachine({
  id: 'toggle',
  initial: 'inactive',
  states: {
    inactive: { on: { TOGGLE: 'active' } },
    active: { on: { TOGGLE: 'inactive' } }
  }
});

const { initialState } = toggleMachine;

const toggledState = toggleMachine.transition(initialState, 'TOGGLE');
toggledState.value;
const untoggledState = toggleMachine.transition(toggledState, 'TOGGLE');
untoggledState.value;
// => 'inactive'
```

### Usage (service)

```js
import { createMachine, interpret } from '@xstate/fsm';

const toggleMachine = createMachine({});

const toggleService = interpret(toggleMachine).start();

toggleService.subscribe((state) => {
  console.log(state.value);
});

toggleService.send('TOGGLE');
toggleService.send('TOGGLE');
toggleService.stop();
```

---
_Source: https://npm.io/package/@xstate/fsm · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._