excalidraw

Write an array of Excalidraw element objects (rectangles, arrows, text) and wrap it in the standard envelope with type, version, source, elements, and appState keys. Save it as a .excalidraw file and drag it onto excalidraw.com to view and edit.

Use container binding: the shape lists the text in boundElements and the text element sets containerId back to the shape, with matching text and originalText. The label property does not exist in Excalidraw and is silently ignored, producing blank shapes.

Run the included upload.py script with your .excalidraw file path. It encrypts the diagram client-side with AES-GCM, uploads it to excalidraw.com without an account, and prints a shareable URL containing the decryption key.

Blank shapes usually mean the invalid label property was used instead of container binding. Invisible text on dark backgrounds happens when the default #1e1e1e strokeColor is kept; set text strokeColor to #e5e5e5 for dark mode diagrams.

The upload script requires the Python cryptography package, installed with pip install cryptography. Diagram creation itself needs nothing beyond writing JSON, since excalidraw.com renders the file directly in the browser.