Skip to content
Mintall

Certificates

An MC4P certificate is a JSON-LD document that describes one product or one image, plus a signed proof that Mintall issued it for a specific domain.

Both endpoints are public. Responses carry Cache-Control: public, max-age=86400, so a crawler can cache a certificate for a day.

Fetch a product certificate

Section titled “Fetch a product certificate”
Terminal window
curl https://api.mintall.ai/api/v1/mc4p/products/$PRODUCT_ID/certificate

Mintall publishes the certificate as its own JSON-LD block on the product page, alongside whatever product markup the store already emits. It identifies the same product by productID and url.

{
  "@context": ["https://schema.org", { "mintall": "https://mintall.ai/ns/" }],
  "@type": "Product",
  "productID": "...",
  "url": "https://merchant.example/products/pendant",
  "mintall:issuedFor": { "domain": "merchant.example", "productID": "..." },
  "mintall:status": { "canonicalSource": "..." },
  "mintall:images": [...],
  "mintall:trust": { "certifiedAssets": 4, "totalAssets": 5, "coveragePercent": 80 },
  "verification": { "verifyEndpoint": "...", "hasSignature": true },
  "proof": { "type": "JsonWebSignature2020", "jwt": "eyJ...", "algorithm": "RS256" }
}

mintall:trust reports coverage, not a score. An aggregate the issuer computes about itself isn’t independently checkable, so the block carries only the two counts and their ratio — all three signed into the JWT, so a verifier can confirm them.

Fetch an asset certificate

Section titled “Fetch an asset certificate”
Terminal window
curl https://api.mintall.ai/api/v1/mc4p/assets/$ASSET_ID/certificate

An asset certificate is the full expansion of one entry in the product certificate’s mintall:images[] array, as a mintall:-namespaced ImageObject. It adds mintall:contentCredentials (the C2PA manifest summary and hashes) and mintall:nft where one exists.

When a certificate has no proof

Section titled “When a certificate has no proof”

Every response is one of three outcomes:

if (res.status === 404) {
  // Not served by Mintall: disabled, deleted, or never ingested.
} else if (!certificate.proof) {
  // Known to Mintall, not currently publishing trust data. Not a failure.
} else {
  // Signed by Mintall and verifiable.
}

A product that exists but is not active — the merchant has visibility off, or the product sits outside their plan capacity — returns 200 with identity fields only. mintall:images, mintall:trust, verification, and proof are omitted:

{
  "@context": ["https://schema.org", { "mintall": "https://mintall.ai/ns/" }],
  "@type": "Product",
  "productID": "...",
  "url": "https://merchant.example/products/pendant",
  "mintall:issuedFor": { "domain": "merchant.example", "productID": "..." },
  "mintall:status": { "canonicalSource": "..." }
}

Assets follow their parent product. If it is not active, the asset certificate omits mintall:contentCredentials, mintall:nft, verification, and proof. An asset Mintall does not know, or one with no certificate, returns 404.

The proof block

Section titled “The proof block”

proof.jwt is an RS256 JWT signed by Mintall. It expires 7 days after issuance, so refetch the certificate rather than caching the token past its exp.

Claim Meaning
iss The issuing API base URL
iat Issued at
exp Expires, 7 days after iat
domain The domain the certificate is authorized for

The header carries a kid. Match it against the keys from JWKS to pick the right public key.