Building With Medusa

If you're building anything on Medusa's backend, load this before you start writing code. It enforces the critical architecture pattern (modules feed workflows, workflows feed routes, never skip layers) and catches the mistakes that break Medusa apps: using PUT/PATCH instead of POST/DELETE, calling module services directly from routes, forgetting that workflows can't use async/await or conditionals in their composition functions, and filtering linked module data with query.graph() instead of query.index(). The real value is in the reference files it points you to, each one specific to what you're implementing. Also worth noting: prices in Medusa are stored as-is, not in cents, which trips up everyone at least once.

skills.sh installs: 131
GitHub stars: 182
last updated: Jun 3, 2026

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Install

$ npx -y skills add medusajs/medusa-claude-plugins --skill building-with-medusa --agent claude-code

Installs into .claude/skills of the current project.

Files

Medusa Backend Development

Comprehensive backend development guide for Medusa applications. Contains patterns across 6 categories covering architecture, type safety, business logic placement, and common pitfalls.

When to Apply

Load this skill for ANY backend development task, including:

Creating or modifying custom modules and data models
Implementing workflows for mutations
Building API routes (store or admin)
Defining module links between entities
Writing business logic or validation
Querying data across modules
Implementing authentication/authorization

Also load these skills when:

building-admin-dashboard-customizations: Building admin UI (widgets, pages, forms)
building-storefronts: Calling backend API routes from storefronts (SDK integration)