Development Update - New Releases and Session Node Upgrades

Recent development has focused on the reliability of Session. New releases on iOS, Android and Desktop fixed issues with message delivery, groups, account recovery and app stability, and voluntary upgrades for Session Nodes reduced the resources needed to run a node. Changes to libsession also continue to prepare for the unified Session client.

Development of the apps and network has carried on while the launch of Session Pro is temporarily on hold. Discussions are continuing with an allied privacy ecosystem that wants to support Session's long-term sustainability, and Session's developers look forward to sharing more details with the community.

New app releases

In October, Session 2.15.5 on iOS and Session 1.33.6 on Android fixed issues with message delivery, groups and app stability, including deleted groups reappearing when syncing between devices. Desktop received the same fixes in Session 1.18.2, which also added pinch-to-zoom in the image viewer and separate draft reply quotes for each conversation. Session 1.18.3 followed with a fix for saving attachments from the media gallery and a security update.

Recent November releases continued the focus on reliability. On iOS, Session 2.15.6 fixed an issue where the app could return to onboarding with the account missing, and the app now restores the account automatically where possible. It also added an Export Logs button to the Recovery Password screen to help support investigate a missing account, and clearing a device from the startup error screen now warns that the Recovery Password is needed to restore the account.

Session iOS 2.15.6 also improved network reliability, particularly on IPv6-only networks using NAT64, and fixed several push notification issues, including notifications not arriving after the app closed unexpectedly. The app no longer fails to load new messages when reopened after running in the background, and no longer gets stuck on the loading screen if it was closed while updating. Failed voice message and attachment downloads now show an error and can be retried by tapping them. The release also fixed calls getting stuck on "Connecting", along with several crashes and freezes.

On Android, Session 1.33.7 fixed voice message and audio playback in October. Session 1.33.8 fixed freezes when typing, reacting to messages and opening conversations, and crashes on launch, during calls, with Screen Lock enabled and when opening some documents. Saving an attachment now shows an error if it fails, instead of crashing the app.

Session Node upgrades

Running a Session Node now takes fewer resources. Storage Server 2.12.0, Session Router 1.1.0 and oxend 11.7.0 were released together on October 16, reducing disk, memory and CPU use. oxend 11.7.0 also added an optional light node mode that needs about 1.4GB of disk instead of roughly 20GB. The full details are in Smaller nodes, stronger encryption.

Follow-up releases have since fixed issues found after the October release. Storage Server 2.12.1 and Session Router 1.1.1 improved QUIC connections between Session Nodes and fixed a possible crash at shutdown. Storage Server 2.13.0 adds new capabilities for future Session clients and the Session Push Notification Server (SPNS) allowing short disconnections without losing push subscriptions and reducing the amount of message data needing to be sent to the SPNS for push notifications. Meanwhile oxend saw a 11.7.1 update fixing a rare but possible consensus disagreement if oxend was restarted at just the wrong time, and 11.7.2 was released with major internal rewrite of oxen-core's deepest, darkest, ugliest code (known as "epee").

All of these upgrades are voluntary for now, and will become mandatory in a future Mandatory Session Node Upgrade, which is not yet scheduled. Operators on Debian 12+ or Ubuntu 22.04+ can upgrade from the APT repository:

1. First, sync your repositories:

   sudo apt update

2. Then install updates using:

   sudo apt upgrade

Session Push Notification Server fixes

The SPNS, which handles "fast mode" notifications on Apple and Google mobile devices, has received a major upgrade that optimizes how it tracks accounts and swarms and manages subscriptions through the network's storage servers for fast mode activated accounts. Session's developers found and fixed several edge cases that could result in subscriptions being lost after network swarm changes on the network, as happens as Session Nodes join or leave the network. Additionally, the new code substantially optimizes communications with Session Node storage servers, requiring less notification data to be sent (when talking to 2.13.0 nodes), better prioritizing the order in which account subscriptions are sent out, and providing more assurance against lost notifications when the SPNS needs restarting or upgrading.

Groundwork for the unified Session client

The unified Session client will be built on libsession (previously called libsession-util), a shared library that now holds Session's core functionality. Recent changes to libsession have improved how that core stores data and starts up, and some already reach users through the current apps.

The shared core no longer scans every stored message when it starts, which shortens start-up for accounts with long message histories. libsession 1.9.5, included in Session 2.15.6 on iOS, also improved how the app recovers when its list of Session Nodes is out of date.

Session's developers thank the community for its continued support and patience. Bug reports and feedback from Session users and Session Node operators help make each release more reliable.