[Question] What's "fast mode" all about?

[eabase]

In F-Droid repo I see the following message:

This is an unofficial rebrand of Session without Firebase push service so the "Fast mode" can't be enabled.

• What is is this all about?
• Why is is this allowed on the F-Droid repo without the modded source repo attached?

Please explain.

[pottsandpans]

There are two F-Droid repositories available. One is listed on the official F-Droid repository and is an unofficial build maintained by a community member. We recommend using the official F-Droid release: fdroid.getsession.org.

[talha-thedev]

Fast mode uses Google’s servers instead of your device. Your device checks the app’s notifications about every ten minutes, while Google’s servers check for updates every few seconds because they’re designed to poll more frequently.

But this setting reduces my motivation to use the app, since it reveals that I’m using the Session app. Even if message contents are encrypted, Google can still infer that a Session user is communicating.

I prefer to be a bit patient and receive notifications 4–5 minutes later. At least my privacy feels more protected that way.

Sorry for my poor English.

[ThomasSession]

Hello!
"Fast mode" refers to how Session delivers push notifications to your device. There are two modes:

Fast mode uses Google's Firebase Cloud Messaging (FCM) to send you a push notification the moment a new message arrives on the network. It's fast because Google's infrastructure wakes your device immediately — but the trade-off is that Google's servers are involved in the notification delivery path (they don't see message content, just that a notification needs to be sent). There is also a Huawei equivalent for our Huawei build.

Slow mode ("background polling") doesn't use Google at all. Instead, your device periodically checks the Session network for new messages in the background. This is more private, but means there can be a delay of up to ~15 minutes before you see a new message, depending on Android's background task scheduling.

The F-Droid build you're seeing strips out Firebase entirely (since F-Droid requires fully open-source, Google-free builds), which is why it says fast mode can't be enabled — the FCM dependency simply isn't included in that variant. But that is in the unofficial fdroid repo.