agentmods.dev

ck:backend-development

A guide for building server-side software with Node.js, Python, or Go. It covers web APIs, user access, databases, small services, security, testing, and deployment.

In plain words
What is it for?
Use it to create REST, GraphQL, or gRPC APIs; add authentication; design databases; build microservices; improve performance; address common web security risks; and plan deployment and monitoring.
Why use it?
It helps choose suitable technologies and follow established approaches for common backend tasks. This reduces guesswork when designing, securing, testing, and running server software.

Skill for Claude CodeCodex

88 4d ago A scan 55 tokens original MIT
View the source file manhvann/codexkit
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/manhvann/codexkit/backend-development
Any agent
npx skills add manhvann/codexkit --skill backend-development
Clone the repo
git clone --depth 1 https://github.com/manhvann/codexkit

Made for: Claude Code, Codex.

Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 969 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 $0.00055 $0.00969
Opus 5 $0.00028 $0.00485
Sonnet 5 $0.00011 $0.00194
Haiku 4.5 $0.00006 $0.00097

Measured 2d ago against content hash 5e91cb107bea, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ck:backend-development 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.

Origin

Copies of this mod

3 near-identical copies found in the catalogue:

.agents/skills/backend-development/SKILL.md · 97 lines

How it starts

The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Development Skill

Production-ready backend development with modern technologies, best practices, and proven patterns.

When to Use

  • Designing RESTful, GraphQL, or gRPC APIs
  • Building authentication/authorization systems
  • Optimizing database queries and schemas
  • Implementing caching and performance optimization
  • OWASP Top 10 security mitigation
  • Designing scalable microservices
  • Testing strategies (unit, integration, E2E)
  • CI/CD pipelines and deployment
  • Monitoring and debugging production systems

Technology Selection Guide

Languages: Node.js/TypeScript (full-stack), Python (data/ML), Go (concurrency), Rust (performance) Frameworks: NestJS, FastAPI, Django, Express, Gin Databases: PostgreSQL (ACID), MongoDB (flexible schema), Redis (caching) APIs: REST (simple), GraphQL (flexible), gRPC (performance)

See: references/backend-technologies.md for detailed comparisons

Reference Navigation

Core Technologies:

  • backend-technologies.md - Languages, frameworks, databases, message queues, ORMs
  • backend-api-design.md - REST, GraphQL, gRPC patterns and best practices

Security & Authentication:

  • backend-security.md - OWASP Top 10 2025, security best practices, input validation
  • backend-authentication.md - OAuth 2.1, JWT, RBAC, MFA, session management

Performance & Architecture:

  • backend-performance.md - Caching, query optimization, load balancing, scaling
  • backend-architecture.md - Microservices, event-driven, CQRS, saga patterns

Quality & Operations:

  • backend-testing.md - Testing strategies, frameworks, tools, CI/CD testing
  • backend-code-quality.md - SOLID principles, design patterns, clean code
  • backend-devops.md - Docker, Kubernetes, deployment strategies, monitoring
  • backend-debugging.md - Debugging strategies, profiling, logging, production debugging
  • backend-mindset.md - Problem-solving, architectural thinking, collaboration

Key Best Practices (2025)

Security: Argon2id passwords, parameterized queries (98% SQL injection reduction), OAuth 2.1 + PKCE, rate limiting, security headers

Read the full file on GitHub · 97 lines

Files

What ships with it

11 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 · 97 lines · 55 tokens per session scan A 5e91cb107bea

Subscribe to this mod's changes

ck:backend-development is a skill published in the GitHub repository manhvann/codexkit (88 stars, last pushed 4d ago), licensed MIT. It adds 55 tokens to every session and 969 once invoked, about $0.0003 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.

Backend and APIsSecurityTesting
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