How to use the Backend Patterns Guide agent skill

What the skill makes the agent do

The skill is a single SKILL.md file. It contains examples of how to design REST routes, separate data access from business logic, write database queries that avoid the N+1 problem, add Redis or in-memory caching, wrap requests in authentication middleware, and handle errors in a consistent shape.

When you ask for backend work that matches these topics, the agent uses this material as its reference rather than inventing a structure from scratch. The file is written in Spanish and is mostly code examples, not executable tooling.

• REST routes based on resources, with query parameters for filtering, sorting and pagination
• A repository interface with a Supabase implementation, plus a service layer that holds business logic
• Selecting only the columns you need and batch loading related records to avoid N+1 queries
• Cache-aside and Redis caching with a 5-minute expiry in the examples
• A withAuth middleware wrapper for API handlers
• A centralised error handler that returns consistent JSON responses

Install the backend-patterns skill

Download the ZIP for this skill from this page. Unzip it so that the skill folder sits in one of two places: ~/.claude/skills/ to make it available across your projects, or the .claude/skills/ folder inside a specific project to limit it to that project.

If you use the Claude apps instead of a local setup, you can upload the skill under Settings → Capabilities → Skills. The skill package contains only SKILL.md, so there is nothing else to install from it.

Trigger the skill with natural requests

You do not need a special command. Describe the backend task in plain language and mention the kind of work involved. The skill's own list of triggers covers REST or GraphQL endpoint design, repository, service or controller layers, database query optimisation (N+1, indexing, connection pooling), caching (Redis, in-memory, HTTP cache headers), background jobs, error handling and validation, and middleware for auth, logging or rate limiting.

Name your stack when you can. Requests that mention Node.js, Express or Next.js API routes match the skill's scope most closely.

• Refactor this Next.js route so the database logic lives in a repository and the business rules live in a service.
• Our product list page runs one query per row to load the seller. Remove the N+1 problem.
• Add Redis caching to the GET /api/markets/:id handler with a sensible expiry.
• Wrap these Express handlers with authentication middleware that returns 401 for a missing or invalid token.
• Make all of our API error responses follow one shape and return 400 for validation failures.

Example: applying the repository and service pattern

Suppose you have a route that queries the database directly. Ask the agent to move the query behind a repository interface, then to put the rules in a service class that receives the repository through its constructor. The skill shows exactly this split, with a SupabaseMarketRepository and a MarketService as the model.

Review the result before committing. The examples are illustrative and some parts are left as placeholders, so the agent's output still needs your real types, data and tests.

Know what you need before you start

The skill does not install anything. It assumes you already have a Node.js or TypeScript project to apply the patterns to. If you use the examples directly, you also need a Supabase client and a Redis client in that project, because the code calls them. These are examples only.

The skill runs no scripts and uses no network access, according to its description. Its risk comes from the code it helps you write, not from the file itself.

• A Node.js or TypeScript project
• A Supabase client, if you use the Supabase examples
• A Redis client, if you use the caching examples

Safety notes before you copy code

Do not paste the examples into production unchanged. The source states that some details are omitted, including the findByIds method, the vector search implementation and the body of the error-handling class. The auth middleware also simply trusts the result of verifyToken, so you must write and review real token verification yourself.

Treat the agent's output as a draft. Check authentication, input validation, database permissions and error messages before deployment.

• findByIds, the vector search implementation and the ApiError class body are not fully written in the source
• withAuth trusts verifyToken; add and review real verification
• Security review is required for any production system