Badge Verifier — free sample (validation logic only)

This is the pure-logic layer of verify/index.html from the Certificate Issuer Self-Host Kit, trimmed to taste: the exact checks the full verifier runs, runnable right here. Open your browser console and try:

What this sample does not include — all in the full kit's one-file verifier:

• the paste-a-badge UI (textarea, JSON file drop, example shape button)
• the rendered credential card (badge name, issuer, serial)
• the interactive recipient check ("does this badge belong to this email?")
• the hosted-copy comparison (fetch the assertion at its id URL and compare canonical JSON byte-for-byte)
• print styles and the full page layout