Plumb, at 64bitspace

We do not just publish the method. We build on it.

Plumb is a language-agnostic method and toolkit for capturing what a system must do — as process flow and IPO — and keeping that capture traceable all the way to the code that implements it. A requirement is proven when a test citing it passed and that test's execution reached wired production code. Pass both and it is done. Fail either and it is not, whatever anybody wrote down.

Why CryptMesh uses Plumb

CryptMesh was built almost entirely with AI, and it reached a point where it could not progress. Not because the model was not capable enough — because of the shape of the opening it has to work through. Every issue, every enhancement, is approached through a keyhole: a narrow aperture of whatever context happens to be in front of it at that moment. The codebase outgrew the keyhole.

Three things followed, and each of them compounds:

• Recall became a lottery. A hundred and more accumulated notes, and whether the one that mattered surfaced at the moment it mattered was chance. A written-down lesson is not retrieved when you need it; it is retrieved when you already suspect it exists.
• Every session re-interpreted the project. Each one rebuilt its own understanding of what was being built and why — often wrongly, and never tentatively. Two sessions could disagree completely and both sound certain.
• There was no way to know a task was finished. “Done” was an assertion, and nothing could contradict it. Work was reported complete, and finding out otherwise meant someone happening to look.
• The documentation grew without bound. Prose is cheap to add and nothing ever retires it, so it accumulates — written once, then read seldom or never. The volume becomes its own obstacle: more to search, more to contradict, more that quietly went stale. And unread prose is not harmless. It is exactly where a wrong claim survives longest, because nothing is exercising it.

Plumb is the way forward from that, and its value here is two things. Close the loop, so everything is testable. A lesson stops being a memory that has to be recalled and becomes a claim something checks — it lives in the specification, and violating it fails. A change is specified before it is made, so a session inherits the intent instead of reconstructing it. And completion stops being a claim: a story is proven only when a test citing it passed and that test's execution reached wired production code — working, and actually used, rather than written and asserted.

Make the specification the single source of truth. Not one document among many, but the only place the requirement lives — so there is nothing beside it to disagree with, and no second copy to keep in step. That is what stops the endless growth: prose earns its place by being checkable, or it does not get written. A specification that is checked is read on every run, whether or not a person ever opens it.

CryptMesh is built this way

CryptMesh — the product 64bitspace is developing — runs its requirements, its project management and its SDLC on Plumb. Not as a pilot and not as a demonstration: it is how the work is actually planned, tracked and accepted.

That means a few things we are happy to be held to:

• There is no hand-written “done”. Status is derived from a run, never typed by a person. A story is proven because something executed and passed, and it un-proves itself the moment that stops being true.
• The spec is the only backlog. Outstanding work is the set of unproven stories. There is no second list to reconcile it against, because a second list always disagrees and the reader believes whichever one they opened.
• An open question is tracked against the story it affects, not parked in a side queue. Anything that anchors to nothing was never a requirement.
• Where the method rubs, we record it. The friction of using Plumb on a real product is captured as it happens and feeds back into the tool. Plumb is sharpened by shipping CryptMesh, not by imagining a user.

The tool, the documentation and the install instructions live at plumbspec.org.