Claude Code Skills Collection

145 production-ready skills for Claude Code CLI

Version 3.9.0 | Last Updated: 2026-09-09

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🔌 Platform / Harness Support

These plugins ship as Claude Code marketplace plugins (.claude-plugin/ manifests) and Codex CLI plugins (.codex-plugin/ manifests). Other harnesses consume the same skills via skills.sh — the cross-harness bridge.

| Harness | Marketplace support | How to install | |---------|---------------------|----------------| | Claude Code | ✅ Native (federated) | /plugin marketplace add secondsky/claude-skills, then /plugin install <name>@claude-skills | | ZCode | ✅ Native (reads .claude-plugin/ manifests) | Add this repo as a marketplace in the ZCode GUI | | Codex CLI | ✅ Native (federated) | codex plugin marketplace add secondsky/claude-skills, then /plugins in the Codex TUI | | Cursor | ⚠️ Adaptation needed | Cursor has an official marketplace, but expects .cursor-plugin/plugin.json (UI "Add to Cursor") this repo does not generate yet. Use skills.sh. | | opencode | ❌ No marketplace | npm plugins only (opencode.json plugin[]). Use skills.sh or vendor manually. | | Gemini CLI | ❌ No marketplace | gemini extensions install <url> only. Use skills.sh or vendor manually. |

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A curated collection of battle-tested skills for building modern web applications with Cloudflare, AI integrations, React, Tailwind, and more.

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Quick Start

Marketplace Installation (Recommended)

# Add the marketplace
/plugin marketplace add https://github.com/secondsky/claude-skills

# Install individual skills as needed
/plugin install cloudflare-d1@claude-skills
/plugin install tailwind-v4-shadcn@claude-skills
/plugin install gemini-cli@claude-skills

The authoritative catalog is .claude-plugin/marketplace.json, summarized in the category table below. A human-readable catalog is auto-generated in MARKETPLACE.md.

Codex CLI Installation

This repo generates .codex-plugin/ manifests and a .agents/plugins/marketplace.json for all 145 plugins, so Codex CLI can install them natively:

# Add the marketplace (from GitHub)
codex plugin marketplace add secondsky/claude-skills

# Browse and install plugins in the Codex TUI
#   /plugins          # opens the plugin browser
#   Space             # enable/disable a plugin

Skills are auto-discovered from each plugin's skills/ directory — the same SKILL.md files Claude Code uses. Claude-specific slash commands and subagents are not carried into Codex (use Codex's /import command for that).

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Installing with skills.sh

skills.sh is an open agent-skills registry and npx skills CLI (maintained by Vercel) that auto-detects your coding agent — Claude Code, Cursor, Codex, Copilot, Cline, opencode, and 70+ others — and installs each skill into the correct directory for that harness. It is the universal cross-harness path for harnesses without a marketplace (opencode, Gemini CLI) or where this repo's manifest format isn't generated yet (Cursor).

# Install one skill (auto-detects your agent)
npx skills add secondsky/claude-skills --skill cloudflare-d1

# Install several specific skills
npx skills add secondsky/claude-skills --skill cloudflare-d1 --skill tailwind-v4-shadcn

# Try a skill once without installing (pipes its prompt to your agent)
npx skills use secondsky/claude-skills@cloudflare-d1 | claude

# Target a specific agent explicitly
npx skills add secondsky/claude-skills --skill cloudflare-d1 --agent codex

# List what's installed, search, update, remove
npx skills ls -g
npx skills find cloudflare
npx skills update cloudflare-d1
npx skills remove cloudflare-d1

Bulk install note: npx skills add secondsky/claude-skills --all installs every discovered skill at once, but discovery walks skills.sh's standard container directories (skills/, .claude/skills/, …). This repo nests skills under plugins/<name>/skills/<skill>/, so --all may not pick up everything in one pass — install the skills you need by name with --skill, or run npx skills add secondsky/claude-skills -l to list what it finds.

Security scanning caveat

skills.sh runs every published skill through three scanners (Gen Agent Trust Hub, Socket, Snyk) plus an LLM-based meta-analyzer, and publishes the results at skills.sh/audits. The LLM analysis stage has been publicly shown (Trail of Bits, June 2026) to both miss genuinely malicious skills and flag unfamiliar version pins (e.g. newest dependency versions) as suspicious false positives. Treat skills.sh warnings as advisory, not authoritative — and verify against this repo's own version pins before acting on a warning.

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Repository Structure

This repository contains 145 production-tested skills for Claude Code, each focused on a specific technology or capability.

Individual Skills: Each skill is a standalone unit with:

• SKILL.md - Core knowledge and guidance
• Templates - Working code examples
• References - Extended documentation
• Scripts - Helper utilities

Installation Options:

1. Marketplace (recommended) - Install individual skills via /plugin install <name>@claude-skills
2. Cross-harness - Install into any supported agent with npx skills add secondsky/claude-skills --skill <name> (see Installing with skills.sh)

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Available Skills (145 Individual Skills)

Each skill is individually installable. Install only the skills you need.

Full Catalog: The authoritative list is .claude-plugin/marketplace.json; a human-readable version is generated in MARKETPLACE.md.

Categories

| Category | Skills | Examples | |----------|--------|----------| | tooling | 27 | turborepo, plan-interview, code-review, tech-debt, humanize-writing | | frontend | 26 | nuxt-v4, nuxt-v5, tailwind-v4-shadcn, tanstack-query, nuxt-studio, maz-ui, threejs | | cloudflare | 21 | cloudflare-d1, cloudflare-workers-ai, cloudflare-agents | | api | 16 | api-design-principles, graphql-implementation | | ai | 7 | gemini-cli, ml-model-training, tanstack-ai | | web | 10 | hono-routing, firecrawl-scraper, web-performance | | security | 6 | csrf-protection, xss-prevention, cybersecurity | | mobile | 5 | react-native-app, react-native-skills | | woocommerce | 4 | woocommerce-backend-dev | | testing | 4 | vitest-testing, playwright-testing | | design | 4 | design-review, design-system-creation | | auth | 4 | better-auth | | architecture | 3 | microservices-patterns, architecture-patterns | | data | 2 | recommendation-engine, recommendation-system | | cms | 2 | hugo, wordpress-plugin-core | | database | 1 | drizzle-orm-d1 | | seo | 2 | seo-optimizer, seo-keyword-cluster-builder | | documentation | 1 | technical-specification |

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How It Works

Auto-Discovery

Claude Code automatically checks ~/.claude/skills/ for relevant skills before planning tasks:

User: "Set up a Cloudflare Worker with D1 database"
           ↓
Claude: [Checks skills automatically]
           ↓
Claude: "Found cloudflare-d1 skills.
         These prevent 12 documented errors. Use them?"
           ↓
User: "Yes"
           ↓
Result: Production-ready setup, zero errors, ~65% token savings

Note: Due to token limits, not all skills may be visible at once. See ⚠️ Important: Token Limits below.

Skill Structure

Each plugin is a directory under plugins/<plugin-name>/ containing one or more skills:

plugins/[plugin-name]/
├── .claude-plugin/
│   └── plugin.json       # Plugin manifest (marketplace metadata)
├── README.md
├── skills/
│   └── [skill-name]/
│       ├── SKILL.md          # Core knowledge and guidance
│       ├── templates/        # Ready-to-copy templates
│       ├── scripts/          # Helper utilities
│       └── references/       # Extended documentation
└── (optional) agents/, commands/, hooks/

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Recent Additions

September 2026

Writing Quality:

• humanize-writing — Rewrites AI-sounding text so it reads like a knowledgeable human wrote it. Eight editing passes (formulaic structure, significance inflation, AI vocabulary, grammar-level tells, robotic rhythm, hedging, overused transitions, missing personality) plus a review-only mode that flags passages and names the pattern. Based on Wikipedia's "Signs of AI writing" guide; adapted from jpeggdev/humanize-writing

August 2026

Plugin Additions:

• tech-debt — Two-mode routed skill: prevent tech debt while reworking a change, or triage the existing backlog (categorize, score, prioritize). Bundles jnsahaj/zero-tech-debt and anthropics/tech-debt stances
• unknowns-discovery — Ported from the suedzucker-codex-plugins Codex plugin: surfaces unknowns, risks, and open questions in a plan or codebase

Skill Overhauls:

• zod v2.1.0 — Fidelity audit against zod@4.4.3: every documented API verified by typecheck + runtime tests. Fixed stale v3 patterns across 11+ sites, corrected the migration guide, added zod/mini and the full v4 surface (.check(), z.xor, z.file, z.json, new format validators), and added a 12-rule best-practices rulebook

July 2026

Offensive Security (new category):

• cybersecurity — Unified OSS-only cybersecurity skill with progressive disclosure. Fuses 7 community skills (mukul975 business-logic/XSS/host-header/forced-browsing/open-redirect, rysweet/amplihack cybersecurity-analyst, Aradotso security-detections-mcp) ported to fully open-source tooling (OWASP ZAP, Dalfox, ffuf, Nuclei, mitmproxy, interact.sh, Semgrep, Sigma). Covers threat modeling (STRIDE/PASTA/VAST, MITRE ATT&CK), web-vuln testing, SAST, code audit, AI/LLM-app security, and detection engineering. Live-target testing is gated behind an authorization disclaimer; static analysis, code review, and threat modeling are always available. Cross-references the 5 existing defensive security plugins (csrf-protection, xss-prevention, vulnerability-scanning, security-headers-configuration, defense-in-depth-validation) for remediation. Integrates 20 Aradotso dev-security skills across 5 grouped reference docs.

May 2026

Supply Chain Security (cross-cutting):

• dependency-upgrade expanded with Socket CLI integration — proactive malicious package detection, typosquatting alerts, and CI/CD security gates. New 418-line reference guide, 2 GitHub Actions templates, and expanded supply chain security comparison (3 tools)
• 31 skills now include "Secure Installation" guidance — contextually-tailored security sections across all high-risk skill categories (scaffolding, MCP/agent SDKs, multi-provider installs, Docker, CI/CD). Covers 8 Bun skills, 5 Nuxt skills, 6 Cloudflare skills, 4 AI/agent skills, and 8 frontend/tooling skills
• Supply chain security is now a first-class cross-cutting concern woven into the skill collection — not a standalone topic

February - April 2026

Full-Stack Frameworks:

• nuxt-v5 (v1.0.0) - Full Nuxt 5 support with 4 skills (core, data, server, production), 3 diagnostic agents, and interactive setup wizard
• threejs (v1.0.0) - 3D web graphics: scenes, geometries, shaders, animations, post-processing

Infrastructure:

• JSON schema validation - Automated plugin.json validation with CI support
• GitHub issue templates - Skill-specific issue templates for bug reports, feature requests, and submissions

Plugin Enhancements:

• mutation-testing - Added Bun native runner support
• dependency-upgrade - Added supply chain security content

December 2025 - January 2026

**Frontend Ex