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Security and hardening Claude skill

The Security and hardening skill helps an AI assistant apply security-first practices when building web applications.

  • MIT licence
  • ★ 108,502 on GitHub (whole repository)
  • Verified against its source 19 Oct 2026
View SKILL.md Repository

What the Security and hardening skill does

It guides the assistant to treat external input, secrets, and authorization checks as high-stakes, covering items such as validating input at the boundary, parameterizing queries, hashing passwords, setting security headers, and limiting request rates. It is meant for use when auditing input handlers or working on user input, authentication, data storage, or external integrations.

What it covers

  • Security headers and CORS configuration
  • Rate limiting for API and auth endpoints
  • Secrets management
  • Personal data minimization, retention, and deletion

How to install it

In Claude Code

/plugin marketplace add addyosmani/agent-skills
/plugin install agent-skills@addy-agent-skills

This plugin also installs: api-and-interface-design, browser-testing-with-devtools, ci-cd-and-automation, code-review-and-quality, code-simplification, constraint-driven-development, context-engineering, debugging-and-error-recovery, deprecation-and-migration, documentation-and-adrs, doubt-driven-development, frontend-ui-engineering, git-workflow-and-versioning, idea-refine, incremental-implementation, interview-me, observability-and-instrumentation, performance-optimization, planning-and-task-breakdown, shipping-and-launch, source-driven-development, spec-driven-development, test-driven-development, using-agent-skills.

Steps change between versions. Check the official instructions before you install.