Fastly Fanout is a publish-subscribe message broker operating at the Fastly edge. It provides customers with the ability to push messages via direct connections that remain open indefinitely rather than requiring clients to poll for data using short-lived HTTPS requests.


This information is part of a limited availability release. For additional details, read our product and feature lifecycle descriptions.


To use Fanout you must purchase a paid account with a contract for Fastly's services.

Limitations and considerations

Keep in mind the following limitations and considerations during limited availability:

  • Fanout is only available for Compute services, not Delivery services. Consider using WebSockets as an alternative for Delivery services.
  • Service chaining can be used with Fanout. During configuration, the service that initially handles requests from an end user (the first service) must be a Compute service and also must be the Compute service that hands off the request to Fanout.
  • Only the Name, Address, Enable TLS, and Override Host origin server settings are supported.
  • Self-signed TLS certificates are not supported. TLS certificates must be signed by a public certification authority.


We bill for Fanout based on a combination of bandwidth, connection time, and number of messages. Bandwidth is included as part of your overall delivery bandwidth rate in your monthly billing statement. Connection time is measured in usage minutes (rounded up to whole minutes) and aggregated monthly. Number of messages is the sum of the total published messages received from the publish API and the total published messages sent to end users.

Was this guide helpful?

Do not use this form to send sensitive information. If you need assistance, contact support.