Matrix Synapse 1.157

Synapse 1.157.0rc1 (2026-07-14)

Please check the relevant section in the upgrade notes as this release removes support for the deprecated MSC3861 Auth Delegation (experimental_features.msc3861).

Features

• MSC4140: Cancellable delayed events: Limit how many delayed events a user may have scheduled at once. (\#19539)
• Support MSC4446 for moving fully read markers backwards. Contributed by @SpiritCroc @ Beeper. (\#19663)
• Add before and after time filters to the 'Redact events of a user' Admin API. (\#19802)
• Updated experimental support for MSC4388: Secure out-of-band channel for sign in with QR. (\#19808)
• Add an exclude_rooms_from_presence configuration option to stop presence being routed between users solely because they share one of the listed rooms. (\#19935)

Bugfixes

• MSC4140: Cancellable delayed events: Update error responses to match their format in the current draft of the MSC. (\#19539)
• Lock Sliding Sync connections when inserting lazy members, to prevent repeated deadlocks. (\#19826)
• Fix the flag_existing_quarantined_media background update skipping some quarantined remote media. Introduced in v1.152.0. (\#19901)
• Fix a bug introduced in Synapse v1.150.0 where reactivating a deactivated and erased user did not restore their profile, breaking login, name changes, and invitations.

Contributed by @m4us1ne. (\#19902)

• Fix a regression where application services that opted into ephemeral events using the legacy de.sorunome.msc2409.push_ephemeral registration flag stopped receiving ephemeral events (including to-device messages used for encryption). Introduced in v1.156.0. (\#19928)
• Fix a bug causing device list pruning to skip some rows when the transaction gets retried. (\#19947)
• Fix presence states being shown to clients forever after presence is disabled, by marking any previously only users as offline. (\#19948)
• Fix SYNAPSE_ASYNC_IO_REACTOR=1 on Python 3.14. (\#19949)

Deprecations and Removals

• Remove support for experimental MSC3861 auth delegation, in favour of the stable Matrix Authentication Service integration support. See the upgrade notes. (\#19895)

Internal Changes

• Port the synchronous core of client event serialization to Rust. (\#19837, \#19922)
• Update HomeserverTestCase.get_success(...) and friends to drive async Rust (Tokio runtime/thread pool). (\#19871, \#19879)
• Allow Rust code to have database access via Python database connection pool. (\#19878)
• Add golangci-lint to CI. (\#19888)
• Remove wall-clock dependency of test_redact_messages_all_rooms test, as this caused flakiness. (\#19890)
• Change the MSC3814 dehydrated device /events endpoint from POST to GET. (\#19896)
• Change the MSC3814 dehydrated device /events endpoint paging to match spec conventions. (\#19897)
• Fix storage type mismatches where values were bound with a type that didn't match their database column. (\#19911)
• Speed up deletion of old sliding sync connections by adding an index. (\#19912)
• Add note to 3PID email token request unit tests that the endpoint being tested can have an expected, artificial delay of up to 1s. (\#19916)
• Add an index to sliding_sync_connection_lazy_members to speed up deleting old sliding sync connection positions. (\#19923)
• Fix test_lock_contention being flaky when running against PostgreSQL by budgeting CPU time rather than wall-clock time. (\#19929)
• Fix Complement test flake when restarting Synapse workers (cross-test pollution caused by nginx upstreams being temporarily unavailable). (\#19936)
• Add clean deploy FIXME note for TestOIDCProviderUnavailable (problem tracked by #19937). (\#19938)
• Minor presence performance improvements for large servers. (\#19939)
• Reduce replication traffic caused by presence. (\#19941)
• Add last_active_granularity, sync_online_timeout and idle_timeout options to the presence config section to allow tuning the presence state machine timers. (\#19942)