Lint agent configurations before they silently fail. 414 validation rules across Claude Code, Codex CLI, OpenCode, Cursor, GitHub Copilot, Gemini CLI, Cline, Windsurf, Roo Code, Amp, and Kiro - validates CLAUDE.md, AGENTS.md, SKILL.md, hooks.json, MCP server configs, and plugin manifests. Auto-fix included for safe issues; SARIF output for GitHub Code Scanning. Distributed as CLI (npm + Cargo), official GitHub Action (`agent-sh/agnix`), and IDE extensions for VS Code, JetBrains, Neovim, and Zed. Rules sourced from official specs, academic research on agent prompt design, and real-world failure patterns from production deployments. Mentioned in awesome-claude-code.