# Node.js & Bun Quickstart

> Source: `src/content/docs/actors/quickstart/backend.mdx`
> Canonical URL: https://rivet.dev/docs/actors/quickstart/backend
> Description: Get started with Rivet Actors in Node.js and Bun

---
Prefer to start from a complete project? See the runnable [`hello-world`](https://github.com/rivet-dev/rivet/tree/main/examples/hello-world) example.

## Steps

### Add Rivet Skill to Coding Agent (Optional)

If you're using an AI coding assistant (like Claude Code, Cursor, Windsurf, etc.), add Rivet skills for enhanced development assistance:

```sh
npx skills add rivet-dev/skills
```

### Install Rivet

```sh
npm install rivetkit
```

### Create Actors and Start Server

Create a file with your actors, set up the registry, and start the server:

```ts index.ts
import { actor, setup } from "rivetkit";

export const counter = actor({
	state: { count: 0 },
	actions: {
		increment: (c, x: number) => {
			c.state.count += x;
			c.broadcast("newCount", c.state.count);
			return c.state.count;
		},
	},
});

export const registry = setup({
	use: { counter },
});

registry.start();
```

### Run Server

```sh Node.js
npx tsx --watch index.ts
```

```sh Bun
bun --watch index.ts
```

```sh Deno
deno run --allow-net --allow-read --allow-env --watch index.ts
```

Your server is now running on `http://localhost:6420`. Clients connect directly to the Rivet Engine on this port.

Visit [http://localhost:6420](http://localhost:6420) in your browser (or point your AI agent at it) to open the Rivet developer tools and inspect your actors live.

### Connect To The Rivet Actor

This code can run either in your frontend or within your backend:

### TypeScript

```ts index.ts @hide
import { actor, setup } from "rivetkit";

export const counter = actor({
	state: { count: 0 },
	actions: {
		increment: (c, x: number) => {
			c.state.count += x;
			c.broadcast("newCount", c.state.count);
			return c.state.count;
		},
	},
});

export const registry = setup({
	use: { counter },
});

registry.start();
```

```ts client.ts
import { createClient } from "rivetkit/client";
import type { registry } from "./index";

const client = createClient<typeof registry>("http://localhost:6420");

// Get or create a counter actor for the key "my-counter"
const counter = client.counter.getOrCreate(["my-counter"]);

// Call actions
const count = await counter.increment(3);
console.log("New count:", count);

// Listen to realtime events
const connection = counter.connect();
connection.on("newCount", (newCount: number) => {
	console.log("Count changed:", newCount);
});

// Increment through connection
await connection.increment(1);
```

See the [JavaScript client documentation](/docs/clients/javascript) for more information.

### React

```ts index.ts @hide
import { actor, setup } from "rivetkit";

export const counter = actor({
	state: { count: 0 },
	actions: {
		increment: (c, x: number) => {
			c.state.count += x;
			c.broadcast("newCount", c.state.count);
			return c.state.count;
		},
	},
});

export const registry = setup({
	use: { counter },
});

registry.start();
```

```tsx Counter.tsx
import { createRivetKit } from "@rivetkit/react";
import { useState } from "react";
import type { registry } from "./index";

const { useActor } = createRivetKit<typeof registry>("http://localhost:6420");

function Counter() {
	const [count, setCount] = useState(0);

	// Get or create a counter actor for the key "my-counter"
	const counter = useActor({
		name: "counter",
		key: ["my-counter"]
	});

	// Listen to realtime events
	counter.useEvent("newCount", (x: number) => setCount(x));

	const increment = async () => {
		// Call actions
		await counter.connection?.increment(1);
	};

	return (
		<div>
			<p>Count: {count}</p>
			<button onClick={increment}>Increment</button>
		</div>
	);
}
```

See the [React documentation](/docs/clients/react) for more information.

### Deploy

## Configuration Options

_Source doc path: /docs/actors/quickstart/backend_
