TDD-first feature development — crystallise API as a demo test, drive implementation to pass it, run quality stack and progressive review loop. TRIGGER when: user asks to build new functionality, add a capability, or implement a feature in a Python project; phrases: \"add X\", \"implement Y\", \"build Z feature\", \"create a new module for\". SKIP when: bug fixes (use /develop:fix); refactoring without new behaviour (use /develop:refactor); non-Python projects; .claude/ config changes (use /foundry:manage).
$npx -y skills add borda/ai-rig --skill featureInstalls into the current project.
Run `npx skills use "https://github.com/borda/ai-rig" --skill "borda/ai-rig/feature"` and follow the generated skill instructions now. Read its complete output, redirecting it to a temporary file first if necessary. Resolve relative paths from the supporting-files directory it provides.
Use the skills in "https://github.com/borda/ai-rig" that are relevant to the current task. Run `npx skills add "https://github.com/borda/ai-rig"` and select the relevant skills, then follow their instructions.