Pressto

Deterministic puzzle & activity book generator for print-on-demand publishing.

Pressto turns puzzle definitions into print-ready book interiors (Amazon KDP PDFs). It is the generation engine behind the Bright Grid Press catalog.

Status: 0.0.x — name reservation. This release establishes the gem name and the module namespace. The engines are being built test-first; see the roadmap below.

What it will do

One gem, many engines — each grouping the puzzle types that share generation machinery:

Engine	Types	Notes
Grid search	word search, number search	themed word lists; language-independent number grids
Sudoku family	classic, killer, jigsaw, diagonal	one solver core, variant constraints
Kakuro	cross-sums	constraint-solver moat
Cryptogram	substitution ciphers	public-domain quote corpus
Maze	kids mazes (themed, masked)	provable difficulty grading
Math worksheet	color-by-number, drills	grade-banded, curriculum-checked
Crossword	fill-in (phase 1), codeword	uniqueness-proved
Bible content	verse cloze, who-said-it, memorization	retrieval-only from scripture text
Guided journal	keepsake / memory journals	prompt curation
Prompt content	would-you-rather, jokes, riddles	curated, screened

Every generated puzzle is software-verified: solvable, uniquely solvable (where the type requires it), difficulty-graded by a solving-technique simulator, deduplicated against a registry, and screened for unfortunate content.

Design principles

• Deterministic: generate(params, seed:) is a pure function — same inputs produce a byte-identical result. No wall-clock timeouts in generation logic.
• Standard contract: every engine emits the same JSON-serializable envelope.
• TDD, always: failing test first; edge cases are catalogued and each has a named test.

Full specifications and build order live in the project's technical_planning/ documents.

Development

bundle install
bundle exec rspec

License

Proprietary — all rights reserved. Not licensed for redistribution.