Events

Limits

These limits protect the Socket.IO gateway and define how event subscriptions should be distributed across client IPs, Socket.IO sessions, and authorization context. Start with one Socket.IO session for a client workflow and add more only when you need separate capacity.

Connections per IP

100
Scope
Applies to a single client IP address.
What counts
Active sockets and pending handshakes are counted together so rapid parallel connection attempts cannot bypass the limit.
When exceeded
New handshakes are rejected, or a socket that loses a post-admission race is disconnected with CONN_LIMIT.
CONN_LIMIT

Rooms per socket

400
Scope
Applies to each connected socket session.
What counts
Rooms joined through subscription operations count toward the cap. The socket's private room is excluded.
When exceeded
The subscribe request returns 429 with ROOM_LIMIT and the socket is not joined to the new room.
ROOM_LIMIT

Auth scoped sockets

app 10 / user 3
Scope
Applies separately to app-authenticated and user-authenticated subscriptions.
What counts
App auth sessions count against the application. User auth sessions count against the same application and user pair.
When exceeded
Auth registration fails with AUTH_CONN_LIMIT and the socket is disconnected.
authType app = 10authType user = 3AUTH_CONN_LIMIT

No-room timeout

10s
Scope
Applies after a socket connection is accepted.
What counts
The Socket.IO session must create at least one valid event subscription within the timeout window.
When exceeded
The socket is treated as unused and disconnected with NO_ROOM_TIMEOUT.
NO_ROOM_TIMEOUT
Event TypesReturn to Socket.IO event handling examples.