Raw canvas tester

Paste a Canvas JSON below, optionally a DataPayload, pick a field registry, and click Mount. Useful for verifying that a stored canvas loads and renders in Studio without a host integration. Errors surface inline.

Academia templates: paste your { kind: "academia.id-card-template", ... } shape directly — Cartella normalises it automatically. The id-card registry is forced when an academia template is detected, regardless of the dropdown.