# Woocommerce Backend Dev > Add or modify WooCommerce backend PHP code following project conventions. Use when creating new classes, methods, hooks, or modifying existing backend code in WooCommerce projects. Use when this capability is needed. - Skill: `tomevault-io/woocommerce-backend-dev` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/woocommerce-backend-dev` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/woocommerce-backend-dev/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/woocommerce-backend-dev --- # WooCommerce Backend Development This skill provides guidance for developing WooCommerce backend PHP code according to project standards and conventions. ## Instructions Follow WooCommerce project conventions when adding or modifying backend PHP code: 1. **Creating new code structures**: See [file-entities.md](file-entities.md) for conventions on creating classes and organizing files (but for new unit test files see [unit-tests.md](unit-tests.md)). 2. **Naming conventions**: See [code-entities.md](code-entities.md) for naming methods, variables, and parameters 3. **Coding style**: See [coding-conventions.md](coding-conventions.md) for general coding standards and best practices 4. **Working with hooks**: See [hooks.md](hooks.md) for hook callback conventions and documentation 5. **Dependency injection**: See [dependency-injection.md](dependency-injection.md) for DI container usage 6. **Data integrity**: See [data-integrity.md](data-integrity.md) for ensuring data integrity when performing CRUD operations 7. **Writing tests**: See [unit-tests.md](unit-tests.md) for unit testing conventions ## Key Principles - Always follow WordPress Coding Standards - Use class methods instead of standalone functions - Place new internal classes in `src/Internal/` by default - Use PSR-4 autoloading with `Automattic\WooCommerce` namespace - Write comprehensive unit tests for new functionality - Run linting and tests before committing changes - Prefer bun over npm/bunx for Node.js package management when applicable ## Version Information To determine the next WooCommerce version number for `@since` annotations: - Read the `$version` property in `includes/class-woocommerce.php` **on the trunk branch** - Remove the `-dev` suffix if present - Example: If trunk shows `10.4.0-dev`, use `@since 10.4.0` - Note: When reviewing PRs against trunk, the version in trunk is correct even if it seems "future" relative to released versions --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/secondsky) — claim your Tome and manage your conversions.