# Feature Availability (Shared Contract)

This document defines the shared, cross-app system for enabling and disabling capabilities.

Feature availability is not authorization.

Shared contract:

- Blockers and Guards: [`docs/architecture/shared/BLOCKERS_AND_GUARDS.md`](docs/architecture/shared/BLOCKERS_AND_GUARDS.md:1)

## 1) Core principle (non-negotiable)

Availability is decided once, then applied in multiple places.

- API Guards enforce availability.
- Website Blockers reflect availability for UX.

## 2) Capability model (strict)

Inputs to evaluation:

- operational mode (normal, maintenance, test)
- capability key (stable string)
- action type (view, mutate)
- actor context (anonymous, authenticated)

Outputs:

- allow or deny
- a public reason (maintenance, disabled, coming_soon, hidden, not_configured)

## 3) Non-negotiable rules

1. Default is deny unless explicitly enabled.
2. The API is authoritative.
3. The website is UX-only.