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Passport binding ships behind PASSPORT_BOUND_GRANTS_ENABLED, off by default. It is part of the Agent Trust Registry, Phase 1, and is not yet enabled on the hosted service. The normative text is spec/passport-binding.md.

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Two credentials, two questions

An Agent Passport answers who is this agent? An accredited issuer gives it to the agent after checking who provides it, what software it is and which key it holds. It is an SD-JWT VC signed by the issuer, and the registry keeps the issuer’s attestation of it. A grant answers what may this agent do, for whom? A Principal gives it to the agent, for some scopes, a purpose and a time. It is issued by Grantex after the Principal’s consent, as a grant token. A passport never authorizes anything. A grant may be bound to one.

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A bound grant

With the flag on, the developer passes the passport when requesting the grant, with the rail or verifier the grant is for as audience:
Before the request is recorded, the registry checks that the passport is genuine and current, that its issuer is accredited, that the issuer’s attestation of it is registered and still accepted by both the issuer and the registry, that its key is a proven key of the agent, and that the request stays within the limits the issuer checked. The consent page then shows the agent’s trust level, the issuers and the declared limits before the Principal decides. The grant token carries a reference to the passport, never the passport:
and cnf.jkt equal to the same key thumbprint, so only the holder of the passport’s key can use the grant. A relying party that trusts the registry resolves acceptance_status to learn whether the registry still stands behind the passport, and the key rule tells it that the key presenting the grant is the key the issuer checked.

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When the passport goes away

A bound grant never outlives its passport: it ends at the passport’s exp, or its attestation’s if that is earlier, whatever lifetime was requested. A bound grant’s token is not issued or refreshed once the passport or its attestation has expired, the issuer revokes or suspends the passport, the registry withdraws its acceptance, the issuer is suspended, or the key is compromised or rotated out. The issuer’s status is read again when the registry’s last read of it is no longer fresh; if the issuer’s list cannot be read, no token is issued (status_stale). Revoking grants that were already issued when that happens is the registry cascade, a later milestone; it finds them through the binding recorded for each grant.
Last modified on September 28, 2026