Apps · Design infrastructure

Loop Sudoku

A Sudoku engine that works each step by the rules — and can show you its own reasoning.

Loop Sudoku is not a bog-standard number puzzle. Underneath it is a certifying propagation solver: an engine that solves a grid the way a person is taught to — one logical step at a time — and can then certify each step, grading the puzzle, proving it is solvable by logic alone, and naming the next move before it makes it.

It was built dual-expression from the start: the same solver core runs as a standalone app and as a tab inside the Loop MMT — Multi-Module Theory — ecosystem, sharing one engine behind two shells. The commission behind it came from home — Jamie plays nearly every day — and it set the bar in a single line: make it beautiful and elegant and enjoyable to touch, and make sure all the little details sparkle.

[operator to refine] — Story seeded from the corpus + the P-real-03 specimen frame + the apps roster (the certifying-solver claim, the dual-expression / shared-core-two-shell shape, and the "little details sparkle" mandate). Zone A prose is operator-authored per app; this draft states only what those sources already record.

B · The Founding Prompt

P-real-03 · Design Infrastructure · Large

Make Sure All The Little Details Sparkle

Ed! I want to create a new game- I want to create Loop Sudoku! Jamie is a Sudoku pro. I am decent. She plays just about every day, while I went through a brief phase last year where I played every day and made most of my way through a Sudoku teaching website. I tapped out at the very highest levels. Anyway, I want to create Loop Sudoku, in that I want it to be able to exist either alone as a stand alone app OR as a part of the Loop MMT Ecosystem. So it will need all the hooks and whatnot that are involved with that. I would like this to be good- not just bog standard Sudoku app, but something that is beautiful and elegant and enjoyable to touch and use. I don't want to try to radically engineer anything here- it's just Sudoku after all, but I do want to look to put our special crafty touch anywhere we can- make sure all the little details sparkle, you know?

— Shea Gunther · the prompt whose last line is a whole design drive

This prompt ~470 words: a full build commission with its own process scaffold — which lenses to load, who leads, what not to do — anchored to one plain ask: make it sparkle.

What it became Loop Sudoku — a certifying solver, shared core, two shells.

Dual-expressionForest tab pane

The Anatomy

The prompt disarms its own ambition on purpose: "it's just Sudoku after all" — no radical engineering asked for. The reach is not in what to build but in how well: "make sure all the little details sparkle, you know?" That closing line is the Ceiling drive stated in an operator's own words — the standard is not correctness but delight, applied to the smallest details.

It also names the architecture in a sentence — "either alone as a stand alone app OR as a part of the Loop MMT Ecosystem" — which is why Loop Sudoku was built as one engine behind two shells rather than two apps. Dual-expression is the shape the prompt asked for before anyone drew it.

Computational Profile

Prompt size~470 words · large

ProducedLoop Sudoku · certifying solver

Architectureshared core · two shells

Runs asstandalone · Forest tab pane

CategoryDesign Infrastructure

C · The Files Behind It

Loop Sudoku's code isn't public yet — the source ships with the site's open-source release. Rather than link a repo folder that isn't there, this zone stays honest: the files are coming, not hidden.

When the open-source release lands, this zone gains the file list (a certifying solver core, a puzzle model, and two thin shells) and a live "Read the code" link.

D · Play It

Loop Sudoku runs in a browser — but it isn't served publicly yet. It goes live with the site's open-source release, and this button lights up when it does.

The button reflects the honest state from the manifest (play.ready:false, reason "Coming with the open-source release"): a not-public-yet app reads differently from Loop 2.1 (public, playable now) and from the Butcher app (public, runs locally).