C4 Docs Baked Into Every Template

Architecture docs that live in a wiki die in a wiki. The docs that get read are the ones in the repo — and the docs that get written are the ones the scaffold already included.

Most architecture docs are written after the fact, in a separate tool, by someone who wasn't there. They rot. C4 — Context, Container, Component, Code — works because it's structured, and it works in a repo because it lives next to the code it describes.

Begin with the end in mind: what should a new dev understand in ten minutes? The C4 model answers that — the context the system operates in, the containers it's made of, the components inside them, and the code-level invariants. If those are in the repo, onboarding is a README away.

• Context: what the system talks to and why.
• Container: the deployable units and their boundaries.
• Component: the pieces inside each container.
• Code: the invariants — the decisions that don't change.

Why do architecture docs rot? They live apart from the code, they're written once, and nobody updates them. C4 in the repo fixes all three: it's next to the code, it's structured, and the invariants section is the part that should change least.

Every FACTA Template ships its own README, architecture docs (C4 + invariants), and skeleton. The docs aren't a phase two — they're baked in, so the agent and the human both inherit the architecture instead of guessing it.

This is for the small team that can't afford a dedicated architect but can't afford architectural drift either. C4 in the repo is the cheapest architectural discipline that actually survives — because it lives where the code lives.

Architecture docs work when they're structured, in the repo, and inherited from the scaffold. C4 + invariants baked into every template is the cheapest way to give a small team the discipline of a much larger one.