Board File Fixer — check, preview and fix a .canvas board file

Paste a .canvas board file (JSON Canvas 1.0, the open format Obsidian saves canvases in): your browser reads the JSON strictly with line numbers, checks every card and connection against the spec and the json-canvas skill's checklist (duplicate ids, edges that point nowhere, sides, arrowheads, colours, subpaths, groups), draws the canvas and exports an outline - free. A metered run fixes the file, answering every finding, or builds a new canvas from an outline, and the page checks and draws that file too. Derived from the agent skill @kepano/json-canvas (kepano/obsidian-skills, MIT). Board File Fixer is an independent tool, not affiliated with or endorsed by Obsidian (Dynalist Inc.).