# Effect.ts Quickstart (Beta)

> Source: `src/content/docs/actors/quickstart/effect.mdx`
> Canonical URL: https://rivet.dev/docs/actors/quickstart/effect
> Description: Build a Rivet Actor with the Effect SDK

---
Effect support is in beta. The `@rivetkit/effect` API may change between releases. See the [`hello-world-effect`](https://github.com/rivet-dev/rivet/tree/main/examples/hello-world-effect) and [`chat-room-effect`](https://github.com/rivet-dev/rivet/tree/main/examples/chat-room-effect) examples for complete runnable projects.

## Steps

### Install Rivet

Add `rivetkit`, the Effect SDK, and its Effect peers:

```sh
npm install rivetkit @rivetkit/effect effect @effect/platform-node
```

### Define Your Actor

Split each actor into a public contract and a server-only implementation so the contract can be imported from client code without leaking server details.

The contract declares the actor and its actions. Actions are standalone values with explicit [`effect/Schema`](https://effect.website/docs/schema/introduction/) payloads and successes, validated end to end:

```ts src/actors/counter/api.ts @nocheck
import { Action, Actor } from "@rivetkit/effect";
import { Schema } from "effect";

export const Increment = Action.make("Increment", {
	payload: { amount: Schema.Number },
	success: Schema.Number,
});

export const GetCount = Action.make("GetCount", {
	success: Schema.Number,
});

export const Counter = Actor.make("Counter", {
	actions: [Increment, GetCount],
});
```

The implementation registers the actor with `.toLayer`. The wake function runs once when the actor awakes and returns the action handlers. Persisted state is accessed through a `SubscriptionRef`-like `State` API:

```ts src/actors/counter/live.ts @nocheck
import { Actor, State } from "@rivetkit/effect";
import { Effect, Schema } from "effect";
import { Counter } from "./api.ts";

export const CounterLive = Counter.toLayer(
	Effect.fnUntraced(function* ({ rawRivetkitContext, state }) {
		return Counter.of({
			Increment: Effect.fnUntraced(function* ({ payload }) {
				const next = yield* State.updateAndGet(state, (current) => ({
					count: current.count + payload.amount,
				})).pipe(Effect.orDie);

				// Broadcast the new value to every connected client.
				rawRivetkitContext.broadcast("newCount", next.count);

				return next.count;
			}),
			GetCount: () =>
				State.get(state).pipe(
					Effect.map((current) => current.count),
					Effect.orDie,
				),
		});
	}),
	{
		state: {
			schema: Schema.Struct({ count: Schema.Number }),
			initialValue: () => ({ count: 0 }),
		},
		name: "Counter",
		icon: "calculator",
	},
);
```

### Serve The Registry

Compose the actor layers and serve them with `Registry.serve`. `Registry.layer()` reads engine config from the environment, and the actor layer is provided a `Client` so actors can call other actors:

```ts src/main.ts @nocheck
import { NodeRuntime } from "@effect/platform-node";
import { Client, Registry } from "@rivetkit/effect";
import { Layer } from "effect";
import { CounterLive } from "./actors/counter/live.ts";

const endpoint = process.env.RIVET_ENDPOINT ?? "http://127.0.0.1:6420";

const ActorsLayer = CounterLive.pipe(Layer.provide(Client.layer({ endpoint })));

const MainLayer = Registry.serve(ActorsLayer).pipe(Layer.provide(Registry.layer()));

// Keeps the layer alive. Tears down on SIGINT/SIGTERM.
Layer.launch(MainLayer).pipe(NodeRuntime.runMain);
```

### Run The Server

Set `RIVET_RUN_ENGINE=1` to spawn a local Rivet Engine alongside the server. The engine binary is downloaded and cached the first time you run, so there is nothing else to install:

```sh
RIVET_RUN_ENGINE=1 npx tsx --watch src/main.ts
```

Your server now connects to the Rivet Engine on `http://localhost:6420`. Clients connect directly to the 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.

To point at a remote engine instead, set `RIVET_ENDPOINT=https://...` and omit `RIVET_RUN_ENGINE`.

### Connect To The Rivet Actor

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

### Effect

The Effect client imports the same actor contract from your registry. `Counter.client` yields a typed accessor backed by the client layer:

```ts src/client.ts @nocheck
import { NodeRuntime } from "@effect/platform-node";
import { Client } from "@rivetkit/effect";
import { Effect } from "effect";
import { Counter } from "./actors/counter/api.ts";

const program = Effect.gen(function* () {
	const counter = (yield* Counter.client).getOrCreate("my-counter");

	const count = yield* counter.Increment({ amount: 3 });
	yield* Effect.log(`New count: ${count}`);

	const total = yield* counter.GetCount();
	yield* Effect.log(`Total: ${total}`);
});

const ClientLayer = Client.layer({ endpoint: "http://localhost:6420" });

program.pipe(Effect.provide(ClientLayer), NodeRuntime.runMain);
```

With the server still running, start the client in another terminal:

```sh
npx tsx src/client.ts
```

See the [`chat-room-effect`](https://github.com/rivet-dev/rivet/tree/main/examples/chat-room-effect) example for a larger project with typed errors and actor-to-actor calls.

### TypeScript

A plain RivetKit client can call your Effect actor by name through the same engine. Actor and action names are resolved at runtime, so the client is untyped here:

```ts client.ts @nocheck
import { createClient } from "rivetkit/client";

const client = createClient("http://localhost:6420");

const counter = client.Counter.getOrCreate(["my-counter"]);

const count = await counter.Increment({ amount: 3 });
console.log("New count:", count);
```

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

### Deploy

## Feature Support

The Effect SDK wraps the most common actor features with typed, schema-validated APIs. Everything else is still fully usable through the raw RivetKit context (see [Raw Escape Hatch](#raw-escape-hatch) below), so no feature is off limits, it just isn't typed yet.

| Feature | Effect-native API | Access |
| --- | --- | --- |
| Actor contract & actions | `Actor.make`, `Action.make` | Typed |
| Persisted state | `State.get` / `set` / `update` / `updateAndGet` / `changes` | Typed |
| Typed client | `Actor.client`, `Client.layer` | Typed |
| Typed errors | `RivetError` | Typed |
| Logging | `Logger` | Typed |
| Sleep request | `Actor.Sleep` | Typed |
| Actor address (`actorId` / `name` / `key`) | `Actor.CurrentAddress` | Typed |
| Registry serve / test / web handler | `Registry` | Typed |
| [Events & broadcast](/docs/actors/events) | Not yet wrapped | `rawRivetkitContext.broadcast(...)` |
| [Schedule](/docs/actors/schedule) | Not yet wrapped | `rawRivetkitContext.schedule.*` |
| [Embedded SQLite](/docs/actors/sqlite) | Not yet wrapped | `rawRivetkitContext.db.execute(...)` |
| [Destroy](/docs/actors/lifecycle) | Not yet wrapped | `rawRivetkitContext.destroy()` |
| Queues, connections, vars, alarms | Not yet wrapped | `rawRivetkitContext.*` |
| Lifecycle hooks (`onSleep` / `onDestroy`) | Not yet wrapped | `rawRivetkitContext.*` |
| Raw HTTP / WebSocket handlers | Not yet wrapped | `rawRivetkitContext.*` |

### Raw Escape Hatch

Every wake function receives `rawRivetkitContext`, the underlying RivetKit [actor context](/docs/actors). Reach for it to use any feature that does not have a typed wrapper yet. The typed `state` argument and the raw context point at the same actor, so you can mix both:

```ts src/actors/counter/live.ts @nocheck
export const CounterLive = Counter.toLayer(
	Effect.fnUntraced(function* ({ rawRivetkitContext, state }) {
		return Counter.of({
			Increment: Effect.fnUntraced(function* ({ payload }) {
				// Typed state wrapper
				const next = yield* State.updateAndGet(state, (current) => ({
					count: current.count + payload.amount,
				})).pipe(Effect.orDie);

				// Untyped features run through the raw context
				rawRivetkitContext.broadcast("newCount", next.count);
				rawRivetkitContext.schedule.after(1_000, "tick", {});

				return next.count;
			}),
		});
	}),
	{
		state: {
			schema: Schema.Struct({ count: Schema.Number }),
			initialValue: () => ({ count: 0 }),
		},
		name: "Counter",
	},
);
```

Calls through `rawRivetkitContext` are not validated by `effect/Schema` and their payloads are typed as they are in the base RivetKit API.

## Next Steps

	
- [Actions](/docs/actors/actions) — Define the RPC surface clients call on your actor.

	
- [State](/docs/actors/state) — Persist and load actor state across sleeps and restarts.

	
- [Events](/docs/actors/events) — Broadcast realtime updates to connected clients.

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