{% policy %}

Attributes

Parameter	Type	Required	Description
id	string	—	Unique kebab-case policy id (e.g., 'rate-limit')
source	string	✓	Bare name of the action or event that triggers this policy (e.g., 'add-bookmark')
reaction	string	✓	Bare name of the action triggered as a result (e.g., 'bookmark-added')
outcome	string	—	Optional path outcome that must match for the policy to fire (e.g., 'success')

Valid Parent Contexts

This tag is valid inside: {% domain %}

Defines reactive business logic: “When [Source] happens [on Outcome], then perform [Reaction]”. Policies bridge domains by chaining actions and events together.

Flow diagram integration

When a flow step’s action and a path outcome match a policy’s source and outcome, the compiler automatically appends an implicit system step to the Mermaid diagram showing the reaction action name. This makes event-driven reactive behaviour visible directly on the flow chart without requiring authors to document it manually.

Reactive business rule triggered by action/event pair

tagpolicyactionevent policy-tag-reactive

{% policy source="add-bookmark" outcome="success" reaction="bookmark-added" %}
Every successful save must emit a notification event.
{% /policy %}