AI Agent Interoperability: One Skill, Every Agent

The biggest risk when investing time in AI agent skills is lock-in. If you spend hours building and refining skills for Claude Code, what happens when you want to try Codex CLI? Or when your team uses Cursor?

SKILL.md solves this. It's an open standard for AI agent skills that works across 20+ agents. One skill, every agent.

The lock-in problem

Before SKILL.md, every agent had its own instruction format. Claude Code used CLAUDE.md. Cursor used .cursorrules. Codex had its own system. Skills built for one agent were useless on another.

This created real costs. Teams that standardized on one agent couldn't switch without rewriting all their skills. Creators who wanted to sell skills had to maintain multiple versions. The ecosystem fragmented into incompatible silos.

How SKILL.md enables portability

SKILL.md is a single file format that any compatible agent can read. The format has three parts:

Frontmatter — YAML metadata including the skill name, description, compatible agents, and configuration. This is what tells the agent when to activate the skill.

Instructions — Markdown-formatted instructions that define the skill's behavior. These are natural language instructions that any LLM-based agent can follow.

Supporting files — Optional reference documents, examples, and scripts that the skill can reference.

Because the instructions are in natural language rather than agent-specific code, they work across any agent that supports the format. A code review skill written for Claude Code works identically in Codex CLI, Cursor, Gemini CLI, Copilot Agent Mode, Cline, and every other compatible agent.

Which agents support SKILL.md

As of 2026, SKILL.md is supported by virtually every major AI coding agent:

Claude Code, Codex CLI, Cursor, Gemini CLI, GitHub Copilot (Agent Mode), VS Code, Cline, Roo Code, Goose, Amp, Kiro, OpenCode, Hermes Agent, Agent Zero, and more. The full compatibility list is growing monthly.

What portability means in practice

For individual developers

You can switch between agents without losing your workflow. Try Gemini CLI for a week, go back to Claude Code, try Codex CLI for a side project — your skills follow you everywhere. Install them once per agent and they work.

For teams

Teams don't need to mandate one agent. Different team members can use whichever agent fits their preference while sharing the same skill library. Code review standards, testing practices, and deployment procedures are encoded in skills that work for everyone.

For creators

If you build skills for sale on Agensi, your addressable market is the entire AI agent ecosystem — not just users of one specific agent. A skill listed on Agensi reaches users of 20+ different agents.

The network effect

Interoperability creates a network effect. More compatible agents means more potential users for each skill. More users means more creators building skills. More skills means more value for each agent that adopts the standard. This flywheel is why SKILL.md adoption has accelerated in 2026.

The practical result: the SKILL.md ecosystem has more skills, higher quality skills, and faster growth than any single-agent format could achieve. Browse the catalog on Agensi.