verify_delegation

holdings.proof/mcp-server · Verify this server

Verify a Proof of Delegation — the attestation that a domain authorized a specific agent artifact. Pass either the artifact's card (MCP server.json / A2A agent card) or a raw delegation token, PLUS two facts you established yourself: the artifact identity you resolved (the package you are installing, the endpoint you are calling) and the domain you expect to stand behind it. Both are required — a token can be copied into someone else's card, and any domain owner can mint a valid delegation naming someone else's package, so a verdict without both pins would mean 'some domain said something about some artifact'. WHERE THE IDENTITY MAY COME FROM: it is the artifact you are acting on, and never a value read from inside the artifact you are checking. A name in the artifact's own package.json, card or manifest is self-declared and editable by whoever ships it, so checking it against the delegation compares the artifact with itself. Resolve it afresh at call time instead of reusing a value from earlier in this conversation, which may already be stale. When no independently resolvable identity exists — a local or unpublished artifact — you have nothing to compare against, and that is the honest answer: report it rather than a mismatch, because a mismatch here reads as an accusation against the domain named in the delegation. The verifier walks signature → principal → delegate → revocation status, including the cascade down to the domain control proof. Requires no API key. What a verified result means: the expected domain's controller authorized this artifact for these scopes — NOT that the artifact is safe, audited or endorsed.