Check Web API and CSS feature compatibility in WebF - determine what JavaScript APIs, DOM methods, CSS properties, and layout modes are supported. Use when planning features, debugging why APIs don't work, or finding alternatives for unsupported features like IndexedDB, WebGL, float layout, or CSS Grid.
Install
npx skills add openwebf/webf --skill webf-api-compatibilitynpx skills add openwebf/webf --skill webf-api-compatibility -a claude-code -gnpx skills add openwebf/webf --skill webf-api-compatibility -a codex -ggemini skills install https://github.com/openwebf/webf.git --path skills/webf-api-compatibilitygh skill install openwebf/webf webf-api-compatibilitygit clone --depth 1 https://github.com/openwebf/webf /tmp/openwebf__webf
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/openwebf__webf/skills/webf-api-compatibility ~/.claude/skills/webf-api-compatibility # Claude Code
cp -R /tmp/openwebf__webf/skills/webf-api-compatibility ~/.agents/skills/webf-api-compatibility # Codex, Cursor, Gemini CLI, Copilot, OpenCode