Ask an agent's identity to sign something. If it can't, it isn't an identity. It's a pointer.
Day 2 of 21 · The missing layer
Most agent identity proposals hand you a pointer: a name, a registry id, a DID document, an NFT. Every one of them points at the agent. None of them can act as it. So something else signs on the agent's behalf — a platform key, a service account — and that something is the real identity, unnamed and unrevocable.
The test we apply: an agent's canonical identifier should name a thing that can sign, verify, hold value and execute logic — because those are the acts identity is for.
So every agent in our substrate — person, organization, service — is an ERC-4337 smart account. Its canonical identifier is the DID that names that account (did:ethr; the same subject in CAIP-10 / did:pkh form). We call it the anchor.
What the anchor does that a pointer cannot:
— Verify a signature about itself (ERC-1271): a counterparty checks against the account, not against a platform. — Issue and revoke delegations: the account is the principal that grants; revocation is its own transaction. — Enforce at the moment of commit: caveat enforcers run in the call path when value moves, not in a registry nobody calls. — Be recovered without becoming someone else: guardians rotate the credentials under a custody policy; the address never changes (Day 4). — Authorize money without holding it: a person or organization anchor does not carry the funds. An associated treasury service agent — its own account, chartered under the person or org — transacts, and only under a mandate the principal signed (Day 8). The ontology says which is which, and a verifier can tell them apart.
Run the alternatives through the same test. A DNS name proves control of a domain. An NFT (ERC-8004's identity registry) proves someone owns a token that carries a URI. A signed JSON document proves an issuer signed it. None can delegate a subset of itself, none can enforce a spending ceiling, none can be recovered by a quorum. Attach trust to any of them and you have attached trust to a pointer.
The line: the choice of which DID matters more than the choice of a DID. A did:ethr whose controller is a smart contract is globally unique without a method registry, resolvable against the chain, and — this is the point — executable.
Honest limit: the account, ERC-1271 verification and the delegation surface are live in a running estate. The DID-document projection and public resolvers for the anchor are work in progress.
Question: If your identity layer cannot sign, what does sign on the agent's behalf — and who can revoke that key?
#AgentIdentity #DecentralizedIdentity #ERC4337 #AccountAbstraction #AgenticWeb
Previously: Day 1 — The agentic web has a missing layer. Next: Day 3 — Everything else is a projection.