MSC4284 Policy Server Checker

Warning

This module is highly experimental and subject to breakage, change, and deprecation with no or limited notice. Use at your own risk (but let us know if there's bugs).

Caution

This module automatically disables itself on June 18th, 2025. You should uninstall it when upgrading to Synapse v.131.0 or higher.

Warning

This module may have performance implications for your server, even after the End of Life date above.

Note

This module is now largely replaced by the functionality in Synapse v1.131.0. Users looking for autoredaction may need other tooling if not supported by their policy server.

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A Synapse spam checker module implementation for servers looking to opt in early to MSC4284.

For communities which want added protection and auto-redaction, the module can also be configured to redact messages which fail the policy server checks.

See the matrix.org blog or MSC4284 for more details.

Installing

In your Synapse Python environment:

pip install git+https://github.com/element-hq/policyserv_spam_checker#egg=policy-server-checker

Then add the following to your homeserver.yaml:

modules:
  - module: "policy_server.Checker"
    config:
      # Note: the module does all of its work in the background. The following configuration is
      # only needed for communities which *additionally* want auto-redaction.

      # If set, the user ID to issue redactions as in the room IDs listed below.
      fallback_user_id: "@abuse:matrix.org"
      # If the fallback_user_id is set above, these are the rooms where redactions will be sent
      # for events which fail the room's defined policy server checks.
      fallback_room_ids:
        - "!room:example.org"
        - "!another:example.org"

Synapse will need to be restarted to apply the changes. To modify the config, update accordingly and restart Synapse again.

End of life

This module is expected to be incorporated into Synapse itself in short time, and will currently do a whole lot of nothing on June 18th, 2025. Please disable/uninstall the module if the end of life date has passed.