Developer Guide

For External Developers

This section is for agencies, plugin authors, and store engineers building around UpsellBay.

It focuses on the stable integration surface only:

• Plugin architecture and module boundaries
• Public data identifiers and storage contracts
• REST routes you can call safely
• Hooks and filters intended for extension work

Internal build, release, QA, and team workflow notes are intentionally excluded from this section.

Start Here

• Architecture Overview for the runtime map and extension boundaries
• Data & Storage for identifiers, meta keys, and persistence rules
• REST API for current route contracts
• Hooks & Filters for stable extension points

Integration Rules

• Treat WPAnchorBay\UpsellBay\Core\Constants as the source of truth for shared identifiers.
• Use documented hooks, REST routes, and WooCommerce CRUD objects instead of patching private internals.
• Do not write directly to WooCommerce order tables or rely on admin HTML structure.
• Do not trust client-sent price, discount, or eligibility values when integrating with public routes.