synapse-http-antispam 0.3.0

A Synapse module that forwards spam checking to an HTTP server

synapse-http-antispam

A Synapse spam checker module that forwards requests to an HTTP server.

Discussion

This project was written for use with Meowlnir, so it can be discussed in the Meowlnir room: #meowlnir:maunium.net

Installation

pip install synapse-http-antispam

or

pip install synapse-http-antispam@git+https://github.com/maunium/synapse-http-antispam.git

Configuration

Add the following to your homeserver.yaml:

modules:
  - module: synapse_http_antispam.HTTPAntispam
    config:
      base_url: http://localhost:8080
      authorization: random string
      enabled_callbacks:
        - user_may_invite
      async:
        user_may_join_room: true
      fail_open:
        check_event_for_spam: true

If enabled_callbacks is not specified, all callbacks will be enabled.

See https://element-hq.github.io/synapse/v1.126/modules/spam_checker_callbacks.html for the list of available callbacks. All callbacks except check_media_file_for_spam, check_registration_for_spam and should_drop_federated_event are available.

The module will make HTTP requests to <base_url>/<callback_name> with all function parameters as JSON fields. The authorization field will be sent as a Authorization: Bearer <value> header if specified.

The response body must always be JSON. Any 2xx response will be return NOT_SPAM to Synapse. The content of 2xx responses is ignored, so an empty object is sufficient. Any other response is treated as a rejection and the response body will be returned to the client as-is. If the errcode field is not present in error responses, it will default to M_FORBIDDEN.

If the server returns a non-JSON response or if the request fails, the module will fail closed and reject the callback with an M_UNKNOWN error by default, except for callbacks specified in fail_open. Additionally, the check_event_for_spam callback will fail open by default, unless set to false in fail_open.

Any callbacks set to true in the async map will be executed in the background and will always return NOT_SPAM to Synapse. The response status and data will be ignored for async callbacks.