Synapse 1.155.0 (2026-06-16)

End of Life of Debian 12 Bookworm

The next version of Synapse will not include Debian packages for Debian 12 Bookworm
as it reached end of life on the 10th of June 2026.

Internal Changes

• When building releases, don't cancel Debian package builds when one of them fails. (#19842)

Synapse 1.155.0rc1 (2026-06-09)

Bugfixes

• Limit the to-device EDU size to a reasonable value to mitigate long queues of to-device messages preventing outgoing federation because of the size of the transaction. (#19617)
• Work around bug that sometimes breaks joining restricted rooms that require a remote join. Contributed by @tulir @ Beeper. (#19730)
• Update Sliding Sync to return a new response immediately if a room subscription has changed and produced a new response. (#19734, #19792)
• Fix the /capabilities endpoint returning a 500 error on non-media workers when MSC4452: Preview URL capabilities API is enabled. (#19839)

Improved Documentation

• Document how to see Rust build failure output when using poetry install. (#19818)
• Document that the SQLite version included in Ubuntu LTS, aside from ESM-only versions, is included in our support policy. (#19823)

Internal Changes

• Port the Python Event classes to Rust. (#19701, #19816, #19817, #19819)
• Added tests to ensure that email notification links are sanitized. Contributed by Noah Markert. (#19741)
• Add GcpJsonFormatter logging formatter for use with Google Cloud Logging and GKE deployments. (#19775)
• Add more logging to the to-device message replication stream. (#19801, #19821)
• Port Requester class to Rust. (#19828)