API: Guantr.prototype.can.abstract

The can.abstract sub-method performs an abstract permission check — it returns true if any allow rule exists for the given action and resource key, without evaluating conditions or deny rules.

Use this for UI hints (e.g. "should I show the Edit button?"), not for access control decisions. For a full evaluation against a resource instance, use can(action, [resourceKey, instance]).

Signature

guantr.can.abstract(
  action: string, // or specific action type from Meta
  resource: string, // or typed resource key from Meta
): Promise<boolean>

Parameters

• action: (string) The action being checked (e.g. 'read', 'update').
• resource: (string) The resource key to check (e.g. 'post', 'user').

Returns

• Promise<boolean>: Resolves to true if at least one allow rule exists for the action + resource pair. Returns false if no allow rule is found.

How it Works

1. Retrieves all rules relevant to the given action and resource key using queryRules from the storage adapter.
2. Returns true if any rule with effect: 'allow' is present — regardless of conditions or deny rules.

This is intentionally simpler than can(): it answers "has any permission been granted at all for this resource type?" rather than "is this specific instance accessible right now?".

Examples

// Rules:
// allow('read', 'post')                                — unconditional allow
// deny('read', ['post', { published: ['eq', false] }]) — deny unpublished posts

// Abstract check — ignores the deny rule entirely
const showEditButton = await guantr.can.abstract('read', 'post');
// -> true (an allow rule exists)

// Full evaluation against a specific instance
const unpublishedPost = { id: 1, published: false, title: 'Draft' };
const canRead = await guantr.can('read', ['post', unpublishedPost]);
// -> false (the deny rule matches this instance)

Contrast with can()

Behaviour	can(action, 'resource') (deprecated)	can.abstract(action, 'resource')	can(action, ['resource', instance])
Checks allow rules	✅	✅	✅
Evaluates conditions	❌	❌	✅
Evaluates deny rules	❌	❌	✅
Recommended for	— (use can.abstract)	UI hints	Access control

Migration from can() string-mode

// Before (v1.0.x) — implicit, easy to misuse
await guantr.can('read', 'post');

// After (v1.1.0) — explicit intent
await guantr.can.abstract('read', 'post');

See also: cannot.abstract, can, Concepts: Abstract vs Resource-Aware Checks.