---
title: Rooms
description: Learn about NoLag rooms for organizing topics and managing message namespaces.
---

# Rooms

Rooms provide logical namespaces for organizing topics within your application.

## What are Rooms?

Rooms are containers that group related topics together. They help organize your messaging structure and provide isolation between different contexts (e.g., different game lobbies, chat channels, or user spaces).

```typescript [TypeScript]
import { NoLag } from '@nolag/js-sdk'

const client = NoLag('your_access_token')
await client.connect()

// Set up app and room
const room = client.setApp('my-app').setRoom('game-lobby')

// Subscribe to topics within this room
room.subscribe('chat')
room.subscribe('player-updates')

// Messages are scoped to this room
room.emit('chat', { text: 'Hello lobby!' })
```
```python [Python]
from nolag import NoLag

client = NoLag('your_access_token')
await client.connect()

# Set up app and room
room = client.set_app('my-app').set_room('game-lobby')

# Subscribe to topics within this room
await room.subscribe('chat')
await room.subscribe('player-updates')

# Messages are scoped to this room
await room.emit('chat', {'text': 'Hello lobby!'})
```
```go [Go]
package main

import (
    "fmt"

    nolag "github.com/NoLagApp/go-sdk"
)

func main() {
    client := nolag.New("your_access_token")
    client.Connect()

    // Set up app and room
    room := client.SetApp("my-app").SetRoom("game-lobby")

    // Subscribe to topics within this room
    room.Subscribe("chat", func(data any, meta nolag.MessageMeta) {
        fmt.Println("Chat:", data)
    })
    room.Subscribe("player-updates", func(data any, meta nolag.MessageMeta) {
        fmt.Println("Player update:", data)
    })

    // Messages are scoped to this room
    room.Emit("chat", map[string]string{"text": "Hello lobby!"})
}
```

## Room Types

### Static Rooms

Seeded from the app's blueprint when the app is created, and manageable in the dashboard. These rooms exist permanently (they can be disabled but not deleted) and are ideal for fixed channels like `general`, `announcements`, or `support`.

### Dynamic Rooms

Created programmatically via the REST API for user-specific or session-specific namespaces. Dynamic rooms must be created server-side before clients can use them.

**Rooms never exist implicitly.** The broker does not create a room the first time someone names it. A subscribe or publish to a room it does not know is refused with `unknown_topic` (42940) on the client's `error` event, and nothing is delivered. Create the room through the REST API first, then connect. For per-entity rooms created at runtime, set `config.autoProvisionRooms: true` on the app and call `POST /apps/{appId}/rooms/ensure` (`api.rooms.ensure` in the JavaScript SDK), which is an idempotent create-if-missing capped per app.

#### Step 1: Create Room via API

Room slugs are stored exactly as given (or derived from `name` by lowercasing and replacing runs of other characters with `-`). Pass a `slug` explicitly and use the value from the response when you connect.

```typescript [TypeScript]
import { NoLagApi } from '@nolag/js-sdk'

const api = new NoLagApi('your_api_key')

// Create a dynamic room - inherits topics from app config
const room = await api.rooms.create(appId, {
  name: `Game ${gameId}`,
  slug: `game-${gameId}`
})

console.log('Created room:', room.roomId, room.slug)
```
```python [Python]
from nolag import NoLagApi, RoomCreate

api = NoLagApi('your_api_key')

# Create a dynamic room - inherits topics from app config
room = await api.rooms.create(app_id, RoomCreate(
    name=f'Game {game_id}',
    slug=f'game-{game_id}'
))

print('Created room:', room.room_id, room.slug)
```
```go [Go]
api := nolag.NewAPI("your_api_key")

// Create a dynamic room - inherits topics from app config
room, err := api.Rooms.Create(ctx, appID, nolag.RoomCreate{
    Name: fmt.Sprintf("Game %s", gameID),
    Slug: fmt.Sprintf("game-%s", gameID),
})
if err != nil {
    log.Fatal(err)
}

fmt.Println("Created room:", room.RoomID, room.Slug)
```

#### Step 2: Grant Access (optional)

A room with no grants is public to every actor in the project that can reach the app. To make it private, grant the actors that belong in it. The first grant is what closes the room, so grant everything that needs access, including your own backend services, in the same step. All three REST clients expose room grants; see [Access Control](/docs/concepts/acl) for the full rules.

```typescript [TypeScript]
// Grant one player pub/sub on the room's topics
const grant = await api.rooms.grantActor(appId, room.roomId, {
  actorTokenId: playerActorId,
  permission: 'pubSub',
  topics: ['moves', 'chat']
})

// Inspect and revoke later
const grants = await api.rooms.listActors(appId, room.roomId)
await api.rooms.revokeActor(appId, room.roomId, grant.roomActorAccessId)
```
```python [Python]
from nolag import RoomActorAccessCreate

# Grant one player pub/sub on the room's topics
grant = await api.rooms.grant_actor(app_id, room.room_id, RoomActorAccessCreate(
    permission='pubSub',
    actor_token_id=player_actor_id,
    topics=['moves', 'chat'],
))

# Inspect and revoke later
grants = await api.rooms.list_actors(app_id, room.room_id)
await api.rooms.revoke_actor(app_id, room.room_id, grant.room_actor_access_id)
```
```go [Go]
// Grant one player pub/sub on the room's topics
grant, err := api.Rooms.GrantActor(ctx, appID, room.RoomID, nolag.RoomActorAccessCreate{
    ActorTokenID: playerActorID,
    Permission:   nolag.PermissionPubSub,
    Topics:       []string{"moves", "chat"},
})
if err != nil {
    log.Fatal(err)
}

// Inspect and revoke later
grants, _ := api.Rooms.ListActors(ctx, appID, room.RoomID)
fmt.Println(len(grants), "grants")
_ = api.Rooms.RevokeActor(ctx, appID, room.RoomID, grant.RoomActorAccessID)
```

#### Step 3: Connect via WebSocket

Use the app slug the control plane returned when you created the app (it carries a random suffix, for example `my-app-a3f9`) and the room slug from Step 1:

```typescript [TypeScript]
// After room is created via API, connect to it via WebSocket
const gameRoom = client.setApp(APP_SLUG).setRoom(room.slug)
gameRoom.subscribe('moves')
gameRoom.subscribe('chat')
```
```python [Python]
# After room is created via API, connect to it via WebSocket
game_room = client.set_app(APP_SLUG).set_room(room.slug)
await game_room.subscribe('moves')
await game_room.subscribe('chat')
```
```go [Go]
// After room is created via API, connect to it via WebSocket
gameRoom := client.SetApp(appSlug).SetRoom(room.Slug)
gameRoom.Subscribe("moves", func(data any, meta nolag.MessageMeta) {
    fmt.Println("Move:", data)
})
gameRoom.Subscribe("chat", func(data any, meta nolag.MessageMeta) {
    fmt.Println("Chat:", data)
})
```

Actors only see the rooms that existed when they authenticated, plus rooms the broker re-checks with the control plane on a cache miss. If a client connected before the room was created and its subscribe still fails, reconnect it.

## Public vs Private Rooms

By default, rooms are **public**, meaning any actor with access to the app can connect to them. The moment you attach one or more actors to a room, that room becomes **private**. Only the attached actors can access it.

This means access control is built into room assignment rather than requiring separate permission rules. A few examples:

- **Notifications:** attach a user to their own room, and only they receive their notifications
- **Team chat:** attach team members to a shared room, and outsiders can't join
- **Device telemetry:** attach a device and its owner to a room, isolating the data stream

**No actors attached = public.** At least one actor attached = private. There is no toggle; the presence of actor assignments is what makes a room private. Grants are managed in the dashboard, over the REST API, or with the SDK REST clients (`api.rooms.grantActor`, `listActors`, `revokeActor` and their Python and Go equivalents).

## Topic Inheritance

Every room inherits the topics defined on its parent app. When you create a chat app with `messages` and `_typing` topics, every room in that app, whether static or dynamic, automatically has both topics available. You configure topics once at the app level and they scale to thousands of rooms.

## Topic Resolution

Topics within a room are namespaced automatically. When you subscribe to `chat` in room `game-lobby` of the app whose slug is `my-app-a3f9`, the full topic path is `my-app-a3f9/game-lobby/chat`. That three-part path is the only hierarchy: topic names themselves are single tokens with no `/`.

## Use Cases

- **Game lobbies** - Each game session gets its own room
- **Chat channels** - Separate rooms for different conversations
- **User spaces** - Private rooms for user-specific notifications
- **Multi-tenant apps** - Isolate data between organizations

## Next Steps

- [Learn about Topics](/docs/concepts/topics)
- [Set up Access Control](/docs/concepts/acl)