From Agent Skills for WordPress. Copyright (C) 2026 WordPress Contributors, licensed under GPL-2.0-or-later. Changed from upstream: the compatibility: frontmatter line was dropped when this copy was made in March 2026, and license frontmatter plus this notice were added on 2026-10-24. See NOTICE.md.

WP Abilities API

When to use

Use this skill when the task involves:

• registering abilities or ability categories in PHP,
• exposing abilities to clients via REST (wp-abilities/v1),
• consuming abilities in JS (notably @wordpress/abilities),
• diagnosing “ability doesn’t show up” / “client can’t see ability” / “REST returns empty”.

Inputs required

• Repo root (run wp-project-triage first if you haven’t).
• Target WordPress version(s) and whether this is WP core or a plugin/theme.
• Where the change should live (plugin vs theme vs mu-plugin).

Procedure

1) Confirm availability and version constraints

• If this is WP core work, check signals.isWpCoreCheckout and versions.wordpress.core.
• If the project targets WP < 6.9, you may need the Abilities API plugin/package rather than relying on core.

2) Find existing Abilities usage

Search for these in the repo:

• wp_register_ability(
• wp_register_ability_category(
• wp_abilities_api_init
• wp_abilities_api_categories_init
• wp-abilities/v1
• @wordpress/abilities

If none exist, decide whether you’re introducing Abilities API fresh (new registrations + client consumption) or only consuming.

3) Register categories (optional)

If you need a logical grouping, register an ability category early (see references/php-registration.md).

4) Register abilities (PHP)

Implement the ability in PHP registration with:

• stable id (namespaced),
• label/description,
• category,
• meta:
  • add readonly: true when the ability is informational,
  • set show_in_rest: true for abilities you want visible to clients.

Use the documented init hooks for Abilities API registration so they load at the right time (see references/php-registration.md).

5) Confirm REST exposure

• Verify the REST endpoints exist and return expected results (see references/rest-api.md).
• If the client still can’t see the ability, confirm meta.show_in_rest is enabled and you’re querying the right endpoint.

6) Consume from JS (if needed)

• Prefer @wordpress/abilities APIs for client-side access and checks.
• Ensure build tooling includes the dependency and the project’s build pipeline bundles it.

Verification

• wp-project-triage indicates signals.usesAbilitiesApi: true after your change (if applicable).
• REST check (in a WP environment): endpoints under wp-abilities/v1 return your ability and category when expected.
• If the repo has tests, add/update coverage near:
  • PHP: ability registration and meta exposure
  • JS: ability consumption and UI gating

Failure modes / debugging

• Ability never appears:
  • registration code not running (wrong hook / file not loaded),
  • missing meta.show_in_rest,
  • incorrect category/ID mismatch.
• REST shows ability but JS doesn’t:
  • wrong REST base/namespace,
  • JS dependency not bundled,
  • caching (object/page caches) masking changes.

Escalation

• If you’re uncertain about version support, confirm target WP core versions and whether Abilities API is expected from core or as a plugin.
• For canonical details, consult:
  • references/rest-api.md
  • references/php-registration.md