backend-patterns

A set of server-side design patterns for Node.js applications, including Express and Next.js API routes. It covers how to organize APIs, business logic, database access, caching, errors, authentication, and background work.

In plain words
What is it for?
Use it when designing REST APIs, structuring server code, optimizing database access, adding Redis caching, handling retries, limiting abuse, or moving slow work to job queues.
Why use it?
It helps avoid tangled backend code and common problems such as repeated database queries, unreliable external services, inconsistent errors, and unsafe access control.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/cloudnative-co/claude-code-starter-kit/backend-patterns
Any agent
npx skills add cloudnative-co/claude-code-starter-kit --skill backend-patterns
Clone the repo
git clone --depth 1 https://github.com/cloudnative-co/claude-code-starter-kit

Made for: Claude Code, Codex.

Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 342 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00031 $0.00342
Opus 5 $0.00015 $0.00171
Sonnet 5 $0.00006 $0.00068
Haiku 4.5 $0.00003 $0.00034

Measured 2d ago against content hash 15612dbcc108, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

backend-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/backend-patterns/SKILL.md · 40 lines

What it actually says

Backend Development Patterns

Backend architecture patterns and best practices for scalable server-side applications.

Pattern Categories

API Design

RESTful structure, Repository pattern, Service layer, Middleware pattern. See references/api-patterns.md for implementations.

Database & Caching

Query optimization, N+1 prevention, transactions, Redis cache-aside pattern. See references/database-caching.md for implementations.

Error Handling, Auth & Infrastructure

Centralized error handler, retry with backoff, JWT/RBAC, rate limiting, job queues, structured logging. See references/error-auth-infra.md for implementations.

Quick Decision Guide

Need Pattern
Data access abstraction Repository pattern
Business logic isolation Service layer
Auth/logging/validation Middleware pattern
Expensive DB queries Cache-aside (Redis)
N+1 query problem Batch fetch with Map
Atomic multi-table writes Database transactions
Unreliable external APIs Retry with exponential backoff
Abuse prevention Rate limiter (in-memory or Redis)
Non-blocking operations Job queue

Remember: Choose patterns that fit your complexity level. Not every project needs every pattern.

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 40 lines · 31 tokens per session scan A 15612dbcc108

Subscribe to this mod's changes

backend-patterns is a skill published in the GitHub repository cloudnative-co/claude-code-starter-kit (147 stars, last pushed 8d ago), licensed MIT. It adds 31 tokens to every session and 342 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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