The problem

Coding agents are now table stakes. Cursor, Claude Code, Copilot, and Codex read the project-root agent file and treat it as load-bearing instruction. In practice those files are generic boilerplate at worst and hand-written once-and-never-updated at best. Nobody tracks when they fall out of sync with the brief, the stack, or the design system. Agencies running 15 concurrent client projects feel this most. Every kickoff re-invents the same scaffold, and every re-kickoff quietly drifts.

The approach

Project Spine compiles a brief + repo + optional design tokens into a canonical, content-addressable spine.json. Every rule carries a source pointer so reviewers can audit why a rule exists. A drift check in CI fails the build when the generated files no longer match the inputs. The CLI is deterministic and offline; only the optional hosted workspace touches the network.

The maintainer

I'm Petri Lahdelma. Background in design systems and developer tooling. Project Spine is a one-person project right now; I use it on my own client work and iterate based on what I find. The code is open on GitHub and the thinking is in PRD.md.

If you try it and it breaks, or you disagree with a decision I made, email support@projectspine.dev. I read every message. For security issues, please use security@projectspine.dev per SECURITY.md.

What you won't find

GitHub →Product tour →Email the maintainer →