WebSockets

Fastly supports the use of the WebSocket protocol. This protocol allows you to establish long-lived, two-way, interactive communication sessions between an end user's client (such as a web browser) and your servers.

Limitations and considerations

Keep in mind the following limitations and considerations:

• WebSockets is not compatible with shielding or the Fastly Next-Gen WAF.
• When adding a host to your Fastly service configuration, only the Name, Address, Enable TLS, and Override Host origin server settings are supported with WebSockets.
• When handling a WebSocket request, vcl_log will run at the time the request is accepted rather than when the connection ends.
• Client request headers that are added, removed, or modified on your Request (or req.http in VCL) will be reflected in the WebSocket handoff.
• If you have TLS certificates on your origin server, they must be signed by a public certification authority. Self-signed TLS certificates are not supported.

Billing

Use of the WebSocket protocol is disabled by default. Users assigned the superuser role can enable it on the Products page. Once enabled, any user on your account with the appropriate permissions will be able to use this communications protocol.

Enabling WebSockets on your account will also result in changes to your monthly bill. We base billing for WebSockets on a combination of bandwidth and connection time. Connection time is measured for each connection in usage minutes (rounded up to whole minutes) and aggregated monthly to millions of minutes. Bandwidth is included as part of your overall delivery bandwidth rate in your monthly billing statement.