Validate the why before building through four product diagnostics — a YC-style product diagnostic that produces PRODUCT-BRIEF.md with a go/no-go recommendation, a founder review scoring product-market-fit signals, a user journey audit measuring time-to-value, and ICE feature prioritization.
Install
npx skills add affaan-m/ECC --skill product-lensnpx skills add affaan-m/ECC --skill product-lens -a claude-code -gnpx skills add affaan-m/ECC --skill product-lens -a codex -ggemini skills install https://github.com/affaan-m/ECC.git --path docs/zh-CN/skills/product-lensgh skill install affaan-m/ECC product-lensgit clone --depth 1 https://github.com/affaan-m/ECC /tmp/affaan-m__ECC
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/affaan-m__ECC/docs/zh-CN/skills/product-lens ~/.claude/skills/product-lens # Claude Code
cp -R /tmp/affaan-m__ECC/docs/zh-CN/skills/product-lens ~/.agents/skills/product-lens # Codex, Cursor, Gemini CLI, Copilot, OpenCode