This forces you to document what data your frontend needs without dictating how the backend should implement it. Instead of specifying endpoints and field names, you describe what shows on screen, what actions users can perform, and what states you need to handle. Everything goes into a markdown file that becomes the collaboration point between frontend and backend. The format deliberately includes an "Uncertainties" section and encourages phrases like "push back if this complicates things" because the whole point is inviting discussion, not issuing orders. It's useful when you're building a new feature and need to communicate requirements without stepping on backend's toes about architecture decisions.
npx skills add https://github.com/davila7/claude-code-templates --skill frontend-to-backend-requirements