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

Before deciding what to register, read references/domain-vs-projection.md, abilities live at the domain capability layer; MCP / Command Palette / REST exposure is a projection. Registration shape and exposure shape are different decisions, and conflating them forces re-registration every time a consumer's constraints change.

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)

For grouping decisions (how many abilities to register, and where to put filters vs. new ability names), read references/grouping-heuristic.md first, it keeps you from shipping one atomic ability per REST operation.