Your repo has workflow instructions, session context, and feature specs. None of them answer: what does the product promise to do? That's a different layer — and it needs its own artifact.
A .pbc.md file opens in VS Code, renders on GitHub, and reads like any other Markdown document. Drop it into pbc.stewie.sh and the same file becomes navigable structured UI. One source of truth, two reading experiences.
After running into the same product knowledge gap across multiple SaaS products, I built an open Markdown spec for capturing what your product promises to do. Here's what's in it and why.
A Product Behavior Contract (PBC) is a living, code-grounded spec that describes how your product actually behaves — not how you think it does.