Install

pnpm add @aooth/arbac

Documentation

Full docs, API reference, and recipes: https://aooth.moost.org/arbac/

• Concepts
• Role builder
• Privilege factories
• Scope merging
• Codegen CLI
• API reference

Deny is binary on (resource, action)

.deny(resource, action) short-circuits the entire (resource, action) tuple — there is no scope or filter parameter. Once a deny rule's action regex matches, evaluate() returns { allowed: false } immediately, before any other role's allow scopes are even constructed (see arbac-core/src/arbac.ts:126-131).

If you need "hide rows where condition X", express it as an allow with a filter that excludes X, not as a partial deny:

// ✗ Not supported — no row-level deny.
// .deny("tasks", "query", { scope: { filter: { status: "secret" } } })

// ✓ Use a filtered allow instead.
allowTableRead<UserAttrs, Scope>("tasks", {
  scope: (attrs) => ({
    filter: { tenantId: attrs.tenantId, status: { $ne: "secret" } },
  }),
});

Pinned by UNION-03 and UNION-05 in packages/e2e-demo/test/arbac-union.spec.ts — unscoped deny short-circuits sibling allows, and wildcard .deny("tasks", "*") 403s both row-allow (markDone) and set-allow (new) tuples.

Scopes from multiple roles union via $or — permissive wins

When a user has multiple roles that each allow the same (resource, action), their scopes are merged disjunctively via mergeScopeFilters (see packages/arbac/src/scope/filter.ts). A row matches if ANY scope's filter matches. Consequence: if one scope has no filter (rule registered without scope, or with filter: undefined / filter: {}), the union widens to universe and the more restrictive filters in sibling scopes are silently dropped.

// Role "viewer" — tenant-scoped read on tasks.
.use(allowTableRead("tasks", {
  scope: (attrs) => ({ filter: { tenantId: attrs.tenantId } }),
}))

// Role "tasks-everywhere" — unscoped read on tasks (e.g., for an audit role).
.allow("tasks", "query")  // no scope ← contributes universe to the union

// A user with both roles sees ALL tasks (universe wins), not just their tenant.

This is the natural $or semantic: union of "tenant rows" and "all rows" is "all rows". The takeaway: don't grant an unscoped allow on a resource that other roles are trying to filter. Pinned by the transformArbacFilter empty-vs-undefined coercion tests in packages/arbac-moost/src/db/shared-read-helpers.spec.ts.

License

MIT