as4-411/docs/adr/003-policy-engine-abac.md

ADR-003: Policy Engine Model (ABAC)

Status

Accepted.

Context

Resolution must respect tenant scope and allow/deny rules using an attribute-based model.

Decision

Model

• Policies are stored per tenant with rule_json (ABAC attributes), effect (allow/deny), and priority.
• Tenant is enforced by restricting resolution to that tenant when request.tenant is set.

MVP Rule Shape

• Deny: rule_json.participantId or rule_json.participantIds — exclude those participants.
• Allow (restrictive): if any allow policy exists, rule_json.participantId/participantIds — only include those participants.

Ordering

• Deny applied first; then allow restriction. Policies loaded by tenant and ordered by priority.

Consequences

• Simple allow/deny by participant supported; ABAC can be extended via rule_json and filter logic.