Best Claude Code
Skills for Developers

A skill is a folder containing a SKILL.md file, holding instructions an AI coding agent loads on demand when a task matches its description. Development skills encode process rather than taste: how to write a failing test first, how to reproduce a bug before patching it, what to check before merging. The agent reads them at the moment they become relevant instead of holding everything in context at once.

No, and installing all twelve at once is a mistake. Start with one process skill, either superpowers for a full methodology or tdd for a single constraint. Add specialists when you hit the specific problem they solve: diagnosing-bugs when an agent starts guessing at fixes, security-and-hardening before you handle user input, performance-optimization when something is measurably slow.

Mostly yes. SKILL.md is an open format, so Cursor, Codex CLI, Gemini CLI and other harnesses read the same structure, and the written guidance is portable. What is not portable is tooling. Skills that spawn sub-agents, call harness-specific scripts, or rely on a particular plugin system will lose those parts elsewhere, though the instructions themselves still apply.

Copy the folder containing SKILL.md into .claude/skills in your project, or into the same path in your home directory to make it available across every project. Restart your agent so it registers. Several of these repos also ship as plugins with their own install command, so check the specific README, because the commands differ between repositories.

Because a test gives the agent a clear finish line. Without one, it decides for itself when the work is done and tends to stop early. A failing test written first turns a vague request into a check that passes or fails.

No, and they solve different problems. A skill changes how an agent thinks about a task, because it is instructions. An MCP server changes what an agent can touch, because it is tools and data access. If your agent produces poor quality work, you need a skill. If it cannot reach your database, your issue tracker, or your browser, you need an MCP server. Most serious setups run both.

A skill is executable instruction text that your agent will follow, so treat it like any dependency. Read the SKILL.md before installing it, prefer repositories with named maintainers and recent commits, and be cautious with any skill that instructs the agent to run scripts, fetch remote content, or modify files outside the project. Every repository on this page is public and named, so you can read the source before you trust it.

Every repository here is public and free to read. Licences differ, and each card shows the one its repository publishes, so check that before shipping a skill's contents inside a commercial product. Where a card says none is stated, we found no licence in the repository or the skill's own folder, so default copyright applies and you should ask before redistributing it.