Is the API Security skill free?

Yes. The skill itself is free from jefflester/claude-skills-supercharged. SkillProof publishes the install command and an independent test verdict at no cost.

What is the API Security SkillProof Score?

9.6/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 9/10, docs & honesty 5/5.

How do I install API Security?

Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.

Can I use API Security with Cursor, Copilot, Gemini CLI, Codex or other AI tools?

The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.

API Security

Guardrail checklist that turns a naive endpoint into an auth-checked, injection-safe one.

by jefflester · jefflester/claude-skills-supercharged

Tested · Works

Install — copy the command Download source ↗

Test report

Verdict: Tested · Works
Score: 9.6/10
Tested: Jul 14, 2026
Environment: Claude Code 2.x (agent harness)
Upstream re-checked: Aug 10, 2026 · e056faf

Wrote a naive POST /api/orders endpoint from scratch, then redid it under the skill: it added auth+authorization, a Pydantic schema with bounds, a parameterized query in place of an f-string SQL insert, rate limiting, and a generic error response instead of leaking the exception — closing a real SQL-injection hole outright.

Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works

Installs cleanly 5/5
Triggers reliably 5/5
Output vs. baseline 9/10
Docs & honesty 5/5

What API Security does

A self-contained guardrail skill that enforces API security practices — authentication/authorization, input validation, parameterized queries, XSS/CSRF headers, CORS, rate limiting, and safe error handling — with paired good/bad code examples in Python and JS. Triggers when building or modifying API endpoints, request handlers, or middleware, or when auth/DB-query code is being touched.

How to install API Security

git clone https://github.com/jefflester/claude-skills-supercharged
cd claude-skills-supercharged
mkdir -p ~/.claude/skills
cp -r .claude/skills/api-security ~/.claude/skills/api-security

Skills live in ~/.claude/skills/ (global) or .claude/skills/ (per-project). Restart Claude Code after installing.

Commands — how to trigger API Security

/api-security Guardrail checklist that turns a naive endpoint into an auth-checked, injection-safe one.

It also activates on plain-language prompts like these:

Audit this Express endpoint for OWASP Top 10 issues
Add input validation and auth to my new orders API
Check my login route for SQL injection and XSS

Frequently asked questions

Is the API Security skill free?: Yes. The skill itself is free from jefflester/claude-skills-supercharged. SkillProof publishes the install command and an independent test verdict at no cost.
Does API Security work with Claude Code?: We tested it with Claude Code 2.x (agent harness) on Jul 14, 2026. Verdict: Tested · Works. Wrote a naive POST /api/orders endpoint from scratch, then redid it under the skill: it added auth+authorization, a Pydantic schema with bounds, a parameterized query in place of an f-string SQL insert, rate limiting, and a generic error response instead of leaking the exception — closing a real SQL-injection hole outright.
What is the API Security SkillProof Score?: 9.6/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 9/10, docs & honesty 5/5.
How do I install API Security?: Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
Can I use API Security with Cursor, Copilot, Gemini CLI, Codex or other AI tools?: The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.