Getting Started

Skern is a minimal, agent-first CLI for managing Agent Skills across agentic development platforms. It provides a standardized lifecycle — create, validate, install, remove — for skills that work natively with Claude Code, Codex CLI, OpenCode, Cursor, Gemini CLI, GitHub Copilot, Windsurf, and Continue.

Skills follow the Agent Skills open standard (SKILL.md with YAML frontmatter) and are immediately usable by any compatible platform without adapters or format conversion.

Why skern?

Modern AI coding tools each ship their own skill directory layout — .claude/skills/, .agents/skills/, .opencode/skills/, .cursor/skills/, and so on — with no shared tooling for creation, validation, deduplication, or cross-platform installation.

Skern provides:

• Reusable skill definitions — one SKILL.md per skill, portable across platforms
• Project-scoped or user-scoped registration — local skills for a repo, global skills for your machine
• Overlap detection — fuzzy matching prevents skill duplication before it happens
• Cross-platform installation — install to any supported platform with a single command
• Dynamic skill loading — batch install/uninstall plus per-platform capacity reporting so agents can size their working set to a context budget
• Agent-operable interface — every command supports --json, enabling agents to manage their own skills

Design Principles

• CLI-first — terminal is the primary interface
• File-system native — skills are files, registries are directories
• Declarative platform registry — adding a platform is a one-line append to internal/platform/spec.go
• Agent-agnostic — works with any platform that reads SKILL.md
• Deterministic outputs — same input, same result
• Minimal dependencies — small binary, fast startup
• No cloud lock-in — everything is local, everything is yours

Philosophy

Skills should not live inside models. They should live in code. Versioned. Composable. Auditable. Portable.

What's Shipped

The current release is v0.3.1. Major capabilities already in place:

• Eight platform adapters (Claude Code, Codex CLI, OpenCode, Cursor, Gemini CLI, GitHub Copilot, Windsurf, Continue)
• Cross-platform binaries for macOS, Linux, and Windows
• Skill versioning with semver (skern skill version --bump major|minor|patch)
• skill diff and skill import (URL / GitHub repo / gist)
• Stylistic lint hints in skill validate
• Batch install/uninstall and per-platform capacity reporting

See the CHANGELOG for full release notes and the project's GitHub issues for the live roadmap (MCP server mode, remote catalog search, skill dependencies, etc.).

Next Steps

• Installation — install skern on your machine
• Quick Start — create and install your first skill
• Agent Setup — enable the tool-forming loop
• Writing Skills — author skills agents can actually find and use