Turns the verified claims in a Fetchproof brief - response shapes, field names, limits, error codes, quoted behaviour - into tests and fixtures, so the code is checked against the research rather than against the builder's memory of it.
Install
npx skills add StepenkoAnatoli/Fetchproof --skill contract-testsnpx skills add StepenkoAnatoli/Fetchproof --skill contract-tests -a claude-code -gnpx skills add StepenkoAnatoli/Fetchproof --skill contract-tests -a codex -ggemini skills install https://github.com/StepenkoAnatoli/Fetchproof.git --path fetchproof/skills/contract-testsgh skill install StepenkoAnatoli/Fetchproof contract-testsgit clone --depth 1 https://github.com/StepenkoAnatoli/Fetchproof /tmp/StepenkoAnatoli__Fetchproof
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/StepenkoAnatoli__Fetchproof/fetchproof/skills/contract-tests ~/.claude/skills/contract-tests # Claude Code
cp -R /tmp/StepenkoAnatoli__Fetchproof/fetchproof/skills/contract-tests ~/.agents/skills/contract-tests # Codex, Cursor, Gemini CLI, Copilot, OpenCode