Python SDK

# pip
pip install nolag

# poetry
poetry add nolag

# uv
uv add nolag

import asyncio
from nolag import NoLag

# The slug returned when you created the app (slugs carry a random suffix)
APP_SLUG = "chat-a3f9"

async def main():
    # Create client with your actor token
    client = NoLag("your-actor-token")

    # Connect to NoLag
    await client.connect()

    # Scope to an app and a room. The room must already exist.
    room = client.set_app(APP_SLUG).set_room("general")

    # Subscribe to a topic in the room
    await room.subscribe("messages")

    # Listen for messages on that topic
    def on_message(data, meta):
        print(f"Received: {data}")

    room.on("messages", on_message)

    # Publish a message
    await room.emit("messages", {"hello": "world"})

    # Keep running
    await asyncio.sleep(60)

    # Disconnect when done (synchronous)
    client.disconnect()

asyncio.run(main())

from nolag import NoLag, NoLagOptions, QoS

options = NoLagOptions(
    url="wss://broker.nolag.app/ws",  # Custom broker URL
    reconnect=True,                     # Auto-reconnect on disconnect
    reconnect_interval=5.0,             # Seconds between reconnect attempts
    max_reconnect_attempts=10,          # Max reconnect attempts (default 10; 0 disables reconnection)
    heartbeat_interval=30.0,            # Heartbeat interval in seconds (0 to disable)
    qos=QoS.AT_LEAST_ONCE,              # Default QoS level
    load_balance=False,                 # Enable load balancing
    load_balance_group=None,            # Load balance group name
    debug=True,                         # Enable debug logging
)

client = NoLag("your-actor-token", options)

# Scope topics to an app and room. APP_SLUG is the suffixed slug from the create response
room = client.set_app(APP_SLUG).set_room("general")

# Subscribe, listen, and emit within the room
await room.subscribe("messages")
room.on("messages", lambda data, meta: print(data))
await room.emit("messages", {"text": "Hello from general!"})

# This is equivalent to using full topic paths (with APP_SLUG = "chat-a3f9"):
# await client.subscribe("chat-a3f9/general/messages")
# client.on("chat-a3f9/general/messages", handler)
# await client.emit("chat-a3f9/general/messages", data)

# Room also supports filter management
await room.set_filters("messages", ["lang:en", "lang:fr"])
await room.add_filters("messages", ["lang:de"])
await room.remove_filters("messages", ["lang:fr"])

# Room-scoped presence
await room.set_presence({"status": "online"})
members = await room.fetch_presence()

# Unsubscribe within the room
await room.unsubscribe("messages")

from nolag import SubscribeOptions, QoS

room = client.set_app(APP_SLUG).set_room("general")

# Basic subscription + handler
await room.subscribe("messages")
room.on("messages", lambda data, meta: print(data))

# With options (QoS, filters, load balancing)
options = SubscribeOptions(
    qos=QoS.AT_LEAST_ONCE,
    load_balance=True,
    load_balance_group="workers",
    filters=["priority:high", "region:us"]
)
await room.subscribe("tasks", options)
room.on("tasks", lambda data, meta: print(f"Task: {data}"))

# Client-level equivalent: the full app/room/topic path
await client.subscribe(f"{APP_SLUG}/general/messages")
client.on(f"{APP_SLUG}/general/messages", lambda data, meta: print(data))

# Unsubscribe
await room.unsubscribe("messages")

from nolag import EmitOptions, QoS

# Publish any data (dict, list, string, bytes, etc.)
await room.emit("messages", {"text": "Hello!"})

# With options
options = EmitOptions(
    qos=QoS.AT_LEAST_ONCE,
    retain=True,            # Broker keeps the last message for new subscribers
    filter="priority:high", # Publish with a filter value
    echo=False,             # Per-connection flag; see the note below
)
await room.emit("status", {"online": True}, options)

# Client-level equivalent: the full path
await client.emit(f"{APP_SLUG}/general/messages", {"text": "Hello!"})

from nolag import SubscribeOptions, EmitOptions

room = client.set_app(APP_SLUG).set_room("ops")

# Subscribe with initial filters
await room.subscribe("events", SubscribeOptions(
    filters=["region:us", "priority:high"]
))
room.on("events", lambda data, meta: print(data, meta.filter))

# Replace all filters for a topic
await room.set_filters("events", ["region:eu"])

# Add filters to the existing set
await room.add_filters("events", ["priority:critical"])

# Remove specific filters
await room.remove_filters("events", ["region:eu"])

# Clear all filters (switches back to wildcard / receive all)
await room.set_filters("events", [])

# Publish with a filter value
await room.emit("events", {"msg": "US high-priority"},
    EmitOptions(filter="region:us"))

from nolag import ConnectionStatus

# Listen for connection events
client.on("connect", lambda: print("Connected!"))
client.on("disconnect", lambda reason: print(f"Disconnected: {reason}"))
client.on("reconnect", lambda: print("Reconnected!"))

# Broker errors arrive as NoLagServerError (see Error Handling)
client.on("error", lambda err: print(f"Error: {err}"))

# Hydration: with a hydration webhook configured on the app, the broker sends
# the webhook's response body once per subscribe. `topic` is the bare topic name.
client.on("hydration", lambda topic, data: print(f"Initial state for {topic}: {data}"))

# Check connection status
if client.status == ConnectionStatus.CONNECTED:
    print("We're connected!")

# Listen for ALL messages regardless of topic
def log_all(topic, data, meta):
    print(f"[{topic}] {data} (from: {meta.sender})")

client.on_any(log_all)

# Remove a specific on_any handler
client.off_any(log_all)

# Remove ALL on_any handlers
client.off_any()

# Set presence scoped to a room (recommended)
room = client.set_app(APP_SLUG).set_room("general")
await room.set_presence({"status": "online", "username": "alice"})

# Or set presence with an explicit room ID
await client.set_presence({"status": "online"}, room_id="general")

# Fetch the presence list for a room (list of dicts from the broker)
actors = await room.fetch_presence()
for actor in actors:
    print(f"{actor['actorTokenId']}: {actor['presence']}")

# Get cached presence for a specific actor
actor = client.get_presence("some-actor-token-id")
if actor:
    print(f"{actor.actor_token_id}: {actor.presence}")

# Get all cached presence data
for actor in client.get_all_presence():
    print(f"{actor.actor_token_id}: {actor.presence}")

# Clear your presence
await client.clear_presence()

# Presence events are client-level. Each carries actor_token_id and presence
client.on("presence:join", lambda actor: print(f"Joined: {actor.actor_token_id}"))
client.on("presence:leave", lambda actor: print(f"Left: {actor.actor_token_id}"))
client.on("presence:update", lambda actor: print(f"Updated: {actor.presence}"))

import asyncio
from nolag import NoLag, NoLagServerError, NoLagEncodeError

APP_SLUG = "chat-a3f9"

def on_error(err):
    if isinstance(err, NoLagServerError):
        # A structured frame from the broker (protocol v2)
        print(f"{err.error} ({err.code}) on {err.topic}: {err.hint}")
        if err.error == "unknown_topic":
            # 42940: the room has not been created. Create it via the REST API.
            pass
    elif isinstance(err, NoLagEncodeError):
        print(f"Cannot encode payload for {err.op}: {err}")
    else:
        print(f"Error: {err}")

async def main():
    client = NoLag("your-actor-token")
    client.on("error", on_error)

    try:
        await client.connect()
    except Exception as e:
        print(f"Connection failed: {e}")
        return

    room = client.set_app(APP_SLUG).set_room("general")

    # Local failures raise; broker failures go to on_error
    try:
        await room.emit("messages", {"data": "value"})
    except Exception as e:
        print(f"Emit failed: {e}")

    # Disconnect is synchronous, no await needed
    client.disconnect()

asyncio.run(main())

from nolag import NoLagApi, AppCreate, RoomCreate, ActorCreate

async def main():
    # Create API client with project-scoped API key
    async with NoLagApi("nlg_live_xxx.secret") as api:
        # List apps: PaginatedResult with data and pagination
        apps = await api.apps.list()
        print(f"{len(apps.data)} of {apps.pagination.total} apps "
              f"(page {apps.pagination.page} of {apps.pagination.page_count})")

        # Create a new app. Without topics every subscribe is unknown_topic
        app = await api.apps.create(AppCreate(
            name="my-chat-app",
            description="A real-time chat application",
            topics=["messages"],
        ))
        print(app.slug)  # e.g. "my-chat-app-a3f9": pass this to set_app()

        # Create a room in the app (rooms must exist before clients subscribe)
        room = await api.rooms.create(app.app_id, RoomCreate(
            name="general",
            slug="general"
        ))

        # Create an actor (save the access token!)
        actor = await api.actors.create(ActorCreate(
            name="web-client",
            actor_type="device"  # device, user, service, session, agent, orchestrator, observer
        ))
        print(f"Actor token: {actor.access_token}")

        # Scopes are paginated like apps; rooms and actors lists are plain lists
        scopes = await api.scopes.list()
        print(scopes.pagination.total)

from nolag import NoLag, NoLagOptions, SubscribeOptions

# Option 1: Enable load balancing globally via NoLagOptions
client = NoLag("your-actor-token", NoLagOptions(
    load_balance=True,
    load_balance_group="task-workers"
))

# Option 2: Enable per-subscription
room = client.set_app(APP_SLUG).set_room("image-processing")
await room.subscribe(
    "tasks",
    SubscribeOptions(
        load_balance=True,
        load_balance_group="task-workers"
    )
)
room.on("tasks", lambda data, meta: print(f"Processing: {data}"))

from nolag import (
    # WebSocket Client
    NoLag,              # Main client class
    NoLagOptions,       # Connection options
    SubscribeOptions,   # Subscription options
    EmitOptions,        # Publish options
    ConnectionStatus,   # Connection status enum
    ActorType,          # Actor type enum (client.actor_type after connect)
    QoS,                # QoS level enum
    MessageMeta,        # Message metadata
    ActorPresence,      # Presence info
    NoLagServerError,   # Structured broker error (error, code, topic, hint)
    NoLagEncodeError,   # Payload could not be msgpack-encoded

    # REST API Client
    NoLagApi,           # REST API client
    NoLagApiError,      # API error class
    PaginatedResult,    # data + pagination
    Pagination,         # total, page, page_count
    App, AppCreate, AppUpdate,
    Room, RoomCreate, RoomUpdate,
    Actor, ActorWithToken, ActorCreate, ActorUpdate,
    Scope, ScopeCreate, ScopeUpdate,
)