Source & license

Five Ply is an independent static adaptation of Chessguessr by Assios, observed at 105 GitHub stars, last updated October 25, 2026. Chessguessr is licensed under GNU GPL v3. Original puzzle archive and feedback logic are retained. Positions reference games played on Lichess; this edition does not contact Lichess or imply affiliation.

The new interface, keyboard-accessible board, static archive, local saves, assisted hints and replay controls replace Remix, Firebase statistics, account login, tracking and sharing. No original logo or third-party piece artwork is included; pieces use system Unicode glyphs. All 1,594 five-move continuations were checked for legality with chess.js 0.12.1.

• GNU GPL v3 license
• Complete corresponding source: complete static adaptation, chess.js and build inputs
• chess.js BSD-2-Clause license
• Bundled puzzle records
• Source metadata

Build: use Node with the included package.json dependencies, place puzzles.json with the served files, then bundle main.js with esbuild --bundle --format=iife --target=es2020 --outfile=app.js. Serve the flat files at the site root. No persistent server is needed. Modified 2026-10-30 for SkillSafe. Distributed under GPL-3.0 with no warranty.