diff --git a/proposals/3758-expand-push-rule-conditions.md b/proposals/3758-expand-push-rule-conditions.md new file mode 100644 index 00000000000..93469ffab51 --- /dev/null +++ b/proposals/3758-expand-push-rule-conditions.md @@ -0,0 +1,69 @@ +# MSC3758: Add `event_property_is` push rule condition kind + +Currently the only condition used to match event content for push rules is the `event_match` kind. +This compares a glob-style string against a string value within the event dictionary. The event +dictionary is flattened before conditions are checked to enable matching nested values. + +This approach is currently limited to only checking for string values within the event dictionary +(at any level). This MSC proposes a new exact match type for event content that works with all +JSON types. + + +## Proposal + +### Exact matching event data + +We propose a new type of condition, `event_property_is`. Similar to the current `event_match` +([link to spec](https://spec.matrix.org/v1.3/client-server-api/#conditions-1)), this condition +takes two parameters: `value` and `key`. The exact match compares the `value` to the event data +associated with `key` exactly. Both type and content (when a string) should be identical +(include case). This allows for matching all non-compound JSON types allowed by +[canonical JSON](https://spec.matrix.org/v1.5/appendices/#canonical-json): +i.e. strings, `null`, `true`, `false` and integers. This also provides a simpler +exact string matching mechanism (and any associated performance gains on implementation side without +globbing). + +An example condition may look like (encoded as a JSON object): + +```json +{ + "kind": "event_property_is", + "key": "event.content.is_something", + "value": true +} +``` + + +## Alternatives + +[MSC3862](https://github.com/matrix-org/matrix-spec-proposals/pull/3862) proposes an alternative +solution by converting non-string JSON objects to strings in the `event_match` condition type. + +## Security considerations + +None. + +## Future extensions + +A future MSC may wish to define the behavior of `event_property_is` when +used with a JSON object or array. + +[MSC3887](https://github.com/matrix-org/matrix-spec-proposals/pull/3887) is a +related MSC which attempts to define behavior for searching for a value inside of +an array. + +## Unstable prefix + +While still not part of the Matrix spec, the new push rule condition should be +`com.beeper.msc3758.exact_event_match` instead of `event_property_is`, e.g.: + +```json +{ + "kind": "com.beeper.msc3758.exact_event_match", + "key": "..." +} +``` + +## Dependencies + +None.