Common Platform Event Allocations

Common allocations include allocations for platform event definitions, concurrent CometD clients, and allocations for processes and flows. The common allocations apply to standard-volume and high-volume platform events.
Description Performance and Unlimited Editions Enterprise Edition Developer Edition Professional Edition (with API Add-On)
Maximum number of platform event definitions that can be created in an org 100 50 5 5
Maximum number of concurrent CometD clients (subscribers) across all channels and for all event types 2,000 1,000 20 20
Maximum number of Process Builder processes and flows that can subscribe to a platform event 4,000 4,000 4,000 5
Maximum number of active Process Builder processes and flows that can subscribe to a platform event 2,000 2,000 2,000 5
Maximum number of custom channels that can be created for all events except Real-Time Event Monitoring events

This allocation is separate from the one for custom change data capture channels.

100 100 100 100
Maximum number of custom channels that can be created for Real-Time Event Monitoring events

This allocation is separate from the one for custom change data capture channels.

3 3 3 3
Maximum number of distinct custom platform events that can be added to a channel as part of channel members

If the same platform event is added to multiple channels, it’s counted once toward the allocation.

50 50 5 5
Maximum number of Real-Time Event Monitoring events that can be added to a channel as part of channel members

If the same event is added to multiple channels, it’s counted once toward the allocation.

10 10 10 10
Maximum event message size that you can publish

If your event object has hundreds of custom fields or many long text area fields, you can hit this limit. In this case, the publishing call gets an error.

1 MB 1 MB 1 MB 1 MB
  • The concurrent client allocation applies to CometD and to all types of events: platform events, change events, PushTopic events, and generic events. It doesn’t apply to non-CometD clients, such as Apex triggers, flows, and Process Builder processes. Flows and Process Builder processes apply only to platform events and not to change events. The empApi Lightning component uses CometD and consumes the concurrent client allocation like any other CometD client. Each logged-in user using empApi counts as one concurrent client. If the user has multiple browser tabs using empApi, the streaming connection is shared and is counted as one client for that user. A client that exceeds the concurrent client allocation receives an error and can’t subscribe. When one of the clients disconnects and a connection is available, the new client can subscribe. For more information, see Streaming API Error Codes in the Streaming API Developer Guide.
  • Platform events that originate from an installed managed package share the org’s allocation for the maximum number of platform event definitions.

Note