A "polyfill" that standardizes and centralizes AGENTS.md configuration and Agent Skills support within your repository.
Agent
Aider is a terminal-based AI pair programming tool. It does not have a skills system comparable to the Agent Skills specification, but uses a conventions system (read:) for loading context files and coding standards.
Agent
Claude Code is Anthropic's official CLI for Claude. It features a comprehensive hooks system, native Agent Skills support, and a plugin mechanism for extensibility.
Agent
OpenAI Codex CLI is OpenAI's command-line coding agent. It features full native support for the Agent Skills specification, a built-in skill installer, and environment variable configuration for custom skill directories.
Agent
GitHub Copilot CLI is GitHub's command-line coding agent. It features full Agent Skills support (announced December 2025), custom agents, and automatic loading of cross-agent context files including AGENTS.md and .claude/skills/.
Agent
Cursor provides both an IDE and a standalone CLI agent. These are independent products with different capabilities.
Agent
Gemini CLI is Google's command-line interface for Gemini. It features a comprehensive hooks system, native Agent Skills support (experimental), and a robust extension system for extensibility.
Agent
When creating tests for AGENTS.md support, follow these principles to ensure tests are reliable, portable, and maintainable.