Identify users and devices

Set a User ID in your client setup to connect to PubNub. Use a UTF-8 string up to 92 characters.

User IDs must be unique per app as they identify the client. The client can be an end user, device, or server. One person can use many devices (phone, tablet, laptop). See the relationship between users and devices. PubNub Presence uses User IDs to track online status in real time.

User IDs also support billing and analytics.

Filter by message publisher

You can use User IDs to filter messages by publisher using server-side subscribe filters.

User IDs help calculate your bill under the Monthly Active User (MAU) pricing model. An MAU is a unique user with a User ID who connects to PubNub at least once in a month and sends an API call. If you want to pay for transactions, consider transaction-based pricing.

User ID / UUID

User ID is also referred to as UUID/uuid in some APIs and server responses but holds the value of the userId parameter you set during initialization.

After you create your account and configure the SDK, you can start sending messages.