PuzzleTide CLI — word search, crossword & sudoku generator

Name: puzzletide-mcp
Author: Caravaca-Labs

npm package Docs Agent skills License: MIT

Word search generator, crossword generator, and sudoku generator + solver in one local-first puzzle generator CLI — with printable PDF worksheets, starter word banks, verifiable LLM evals, and bundled agent skills. From the makers of puzzletide.com.

Install

npm install -g puzzletide
ptide --version

The package installs both binaries:

ptide
puzzletide

Related MCP server: Shellagent MCP Server

Why generate puzzles with a CLI

Ask a language model to write a word search and you get a grid where half the words are broken; ask it for a sudoku and you usually get one with several solutions, or none. Grids are exactly the kind of output LLMs are bad at and deterministic code is good at.

PuzzleTide CLI is that deterministic code:

Every word search word is placed and verifiable — placement coordinates are part of the output, and the generators are property-tested.
Every generated sudoku is checked to have exactly one solution.
Every crossword is validated against its own clues before it's returned.
Same --seed in, same puzzle out, on any machine.

The package also ships SKILL.md agent skills, so coding agents (Pi, Hermes, OpenClaw, and other SKILL.md-based systems) reach for the CLI instead of hand-writing grids.

Command model

ptide <namespace> <operation> [input] [options]   # for humans
ptide run <tool-id> [input] [options] --json      # canonical, for scripts/agents
ptide tools list | search <q> | info <id> | docs <id>
ptide agent manifest

Use short commands interactively and canonical tool ids in automation:

ptide sudoku generate --difficulty hard
ptide run puzzle.sudoku.generate --difficulty hard --json

Word search generator

Eight placement directions with easy/medium/hard presets, auto-sized grids (6–30), accent/space/hyphen normalization. Words come from flags, files, or bundled themes:

# Word search from your own words, printed in the terminal
ptide wordsearch generate --words "coral,shark,kelp,wave,tide"

# Themed printable word search (puzzle page + solution page)
ptide wordsearch generate --theme animals/ocean-animals --pdf ocean.pdf

# Kids mode: easy = forward-only words
ptide wordsearch generate --theme seasonal/halloween --difficulty easy

Crossword generator

Interlocking placement with standard crossword numbering, clue-grid validation, and deterministic fallback clues for theme words. Words that cannot interlock are reported instead of silently dropped:

# Crossword with your clues
ptide crossword generate --words "PARIS: Capital of France; TOKYO: Capital of Japan"

# From a JSON file, as a printable PDF
ptide crossword generate --file words.json --pdf review.pdf --title "Unit 4 Review"

Sudoku generator and solver

Easy, medium, hard, and expert sudoku (17–21 givens) with a uniqueness guarantee, an instant solver, and a validator that reports conflicts, solvability, and solution uniqueness:

ptide sudoku generate --difficulty expert --seed 42
ptide sudoku solve "53..7....6..195....98....6.8...6...34..8.3..17...2...6.6....28....419..5....8..79"
ptide sudoku validate --file puzzle.txt
ptide daily        # today's daily sudoku, same for everyone on a given UTC day

Printable puzzles: PDF worksheets and SVG

Every generator takes --pdf <file> for a print-ready worksheet — puzzle page(s) plus a solution page (--paper letter|a4, omit the answer key with --no-solution-page) — and --svg <file> for vector images. Printable word search and printable sudoku sheets for a classroom packet are one loop away:

for i in 1 2 3 4 5; do
  ptide sudoku generate --difficulty medium --seed "$i" --pdf "sudoku-$i.pdf" --title "Sudoku #$i"
done

Prefer ready-made sheets? The mystery and murder printable word search is a reader favorite, with hundreds more at printable puzzles.

Word banks and word tools

30 starter themes (ocean animals, fruits, space, halloween, ...) — browse, search, pattern-match, anagrams, random picks. Bring your own lists via --words/--file, or play the full curated collection at puzzletide.com:

ptide words themes --search dinosaur
ptide words match "c_r_l"        # crossword-style pattern matching
ptide words anagram coral

There's a hangman game in the terminal too: ptide play hangman.

Agent skills

Pi can load the bundled skills directly from this npm package:

pi install npm:puzzletide

The package manifest declares:

{
  "pi": {
    "skills": ["./skills"]
  }
}

Five skills are included: word search, crossword, sudoku, printable puzzles, and agent evals. Each prefers the local CLI and checks ptide, puzzletide, then npx puzzletide. Skills never auto-install anything; agents should ask the user before installing.

MCP server for Claude Desktop, Cursor, and any MCP client

The companion package puzzletide-mcp exposes every non-interactive tool over the Model Context Protocol — the same word search generator, crossword generator, sudoku generator/solver, word tools, and evals, callable from Claude Desktop, Cursor, Windsurf, or any MCP client:

{
  "mcpServers": {
    "puzzletide": {
      "command": "npx",
      "args": ["-y", "puzzletide-mcp"]
    }
  }
}

See docs/mcp.md for tool names, arguments, and per-client setup.

Tools

The MCP server (and ptide run <tool-id>) exposes 15 tools:

puzzle_wordsearch_generate: Generate a word search grid from custom words, files, or themed word banks — every placement verifiable, printable via PDF/SVG.
puzzle_crossword_generate: Generate an interlocking crossword with standard numbering and validated clues.
puzzle_sudoku_generate: Generate easy, medium, hard, or expert sudoku with a guaranteed unique solution.
puzzle_sudoku_solve: Solve a sudoku from its 81-character string and report whether the solution is unique.
puzzle_sudoku_validate: Validate a sudoku grid — conflicts, solvability, and solution uniqueness.
words_categories: List word bank categories.
words_themes: List or search the bundled themed word lists.
words_list: List the words in a theme, filtered by length or count.
words_match: Find words matching a crossword-style pattern (c_r_l).
words_anagram: Find anagrams of the given letters in the word bank.
words_random: Pick a random word, optionally from one theme.
words_stats: Word bank statistics.
eval_generate: Generate reproducible, objectively gradable puzzle tasks for benchmarking LLMs and agents.
eval_check: Grade answers to generated eval tasks by construction — no answer key trusted.
play_daily: Print today's daily sudoku (same for everyone on a UTC day).

Verifiable LLM evals

Puzzle answers are checkable without an answer key: a sudoku answer either satisfies the rules and preserves the givens or it doesn't; a word search answer either spells the word along a straight line in the grid or it doesn't. That makes puzzles clean benchmark tasks for LLM evals — no LLM judge needed:

ptide eval generate --type sudoku --n 20 --difficulty hard --seed 1 --out tasks.json
# ...run your model on tasks.json, collect [{id, answer}] ...
ptide eval check --tasks tasks.json --answers answers.json --json

The (type, difficulty, n, seed) tuple fully determines the task set, so it names a reproducible benchmark.

Library usage

The engines are importable TypeScript with no CLI involved:

import { generateSudoku, generateWordSearch, wordSearchPdf } from 'puzzletide';

const sudoku = generateSudoku({ difficulty: 'hard', seed: 42 });
const search = generateWordSearch({
  words: ['coral', 'shark', 'kelp'],
  directions: ['E', 'S', 'SE'],
  seed: 7,
});
const pdfBytes = await wordSearchPdf(search, { title: 'Ocean Animals' });

More docs:

Online versions

Prefer a browser?

Privacy

Everything runs locally. No account, no API key, no telemetry, no network access.

Development

npm install
npm run build     # tsc → dist/
npm test          # vitest + fast-check property tests (build first: CLI tests run dist/)

The starter word banks are generic, original lists written for this package (scripts/wordbanks-source.json, compiled with npm run build:wordbanks). Theme contributions are welcome — add an entry to the source file and run the build. The full curated PuzzleTide word bank collection is proprietary to puzzletide.com and is not part of this repository.

Citing PuzzleTide CLI

If you use PuzzleTide CLI in your work — for example the verifiable puzzle evals in a model benchmark — please cite it (or use GitHub's "Cite this repository" button):

@software{puzzletide_cli,
  author  = {{Caravaca Labs}},
  title   = {PuzzleTide CLI: word search, crossword \& sudoku generator with verifiable LLM evals},
  year    = {2026},
  url     = {https://github.com/Caravaca-Labs/puzzletide-cli},
  note    = {From the makers of \url{https://puzzletide.com}}
}

Plain text: "PuzzleTide CLI (Caravaca Labs, 2026), https://github.com/Caravaca-Labs/puzzletide-cli — from the makers of https://puzzletide.com."

puzzletide-mcp