Validator

This page checks whether an llmo.json document is well-formed, follows the v0.1 specification, and carries a valid cryptographic signature from the publisher.

In plain English: when an organization publishes an llmo.json file, they’re making structured claims about themselves. Things like which domains they operate, which products are theirs, and which channels are official.

The validator confirms three things:

• Shape. The file parses against the v0.1 JSON Schema.
• Conformance. The claims follow the rules at §5.1 Minimal, §5.2 Standard, or §5.3 Strict.
• Signature. If the document is signed, the signature matches the contents and was made with a key the publisher hosts at their own domain. If individual claims carry their own signatures, those are also verified, letting publishers cryptographically attest specific claims independently of the document-level signature (per §4.3).

That last check is what makes the protocol useful. A signed llmo.json proves the document hasn’t been tampered with since the publisher signed it, and proves it was the publisher who signed it.

It does not prove the publisher’s claims are true (see §4.6 What trust does not mean). The validator gives you cryptographic confirmation of authorship, not adjudication of accuracy.

The validator runs in your browser. The publisher’s public key file (JWKS) is fetched server-side via a Cloudflare Pages Function on llmo.org to bypass cross-origin restrictions; no document content is uploaded to llmo.org.

Browser support note: EdDSA (Ed25519) signature verification requires WebCrypto Ed25519 support, available in Chrome 113+, Firefox 130+, and Safari 17+. Older browsers can still validate ES256-signed and ES384-signed documents normally; EdDSA-signed documents on unsupporting browsers report “browser limitation” rather than a signature failure, since the document itself isn’t broken. If you hit that case, try a current browser or use the LLMO CLI for verification.