Build••18 min readEN
Agent Skills: What's Open-Sourced, What's Not, and How to Build Your Own Runtime
The Agent Skills spec is open. The example skills are open. But what about the runtime that loads, selects, and orchestrates them? Every major tool — Claude Code, Codex, Copilot, OpenClaw — built their own. Here's what's open, what's not, and what you actually need to build.
AI AgentsSkillsOpen SourceMCPAnthropicClaude CodeAgent SDKOpenClawCodexCopilotImplementationArchitecture
