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AI AGENTS6 minStandards That Ship / Ep. 10 · Stage 10-3

ERC-8004 Registry Entry: What It Proves and What Can Change

The agent you vetted last month can have a new owner today. Would you notice?

XIN
Pixel-art night scene at a city gate: a small robot courier holds up a glowing sealed card while a gatekeeper compares its seal to a carved stone registry tablet. A thin cyan thread links card and tablet, and the gate stays shut.

IN 30 SECONDS

An ERC-8004 entry is an on-chain token that shows who registered an agent, who owns it now, and which file it points to. It can change owner, and its reputation can be faked.

KEY TAKEAWAYS · 3

  • An ERC-8004 entry is an ERC-721 token in an Identity Registry that points to a registration file.
  • The token can be transferred. A Transfer event or a cleared payment wallet since your last review means: re-check.
  • Reputation only means something when filtered by reviewers you already trust: the Draft warns that fake reputation is possible.
On this page

What does an ERC-8004 entry tell you?

IN SHORT An ERC-8004 entry tells you who registered an agent, who owns that registration today, and which file it points to.

WORDS TO KNOW

ERC-8004 entry
A record in an on-chain registry (kept on a blockchain), defined by the ERC-8004 Draft: a unique, transferable ERC-721 token with an owner and a link to a file.
Registration file
The file an ERC-8004 entry links to. It lists the agent’s services, such as its Agent Card URL, and the entries it claims.
Sybil attack
One actor running many fake identities, here fake reviewers, to push a score up or down.

An ERC-8004 entry A record in an on-chain registry (kept on a blockchain), defined by the ERC-8004 Draft: a unique, transferable ERC-721 token with an owner and a link to a file. See the glossary is an ERC-721 token in an Identity Registry, which the Draft expects to be one per chain. Its number is the agentId. Its link, the agentURI, leads to a Registration file The file an ERC-8004 entry links to. It lists the agent’s services, such as its Agent Card URL, and the entries it claims. See the glossary over https://, ipfs:// or a base64 data URI.

READING ONE ENTRY

Flow diagram: 3 stepsFlow diagram: 3 steps. Token in the registry, then The link. The link, then Registration file.1Token in the registryagentId and its owner2The linkhttps://, ipfs:// or a dataURI3Registration fileServices, such as the cardURL

Step 1. Read the token. Ask the registry who owns this agentId.

Pick a step to see it move
  1. Read the token Ask the registry who owns this agentId.
  2. Follow the link Read the agentURI the token points to.
  3. Open the file It lists the agent’s services, such as its card URL.
Simplified. The token can change owner. A pointer change leaves a public log, but an https file behind it can change silently.

ERC-8004 is a Draft in the ethereum/ERCs repository, so read the current file before you build on any of this. One detail there: if the file lists no supported trust model, the entry is for discovery only, not trust.

IN PLAIN WORDS

The entry is a numbered ticket on a public ledger. Its holder can hand it on, and it points to a file that describes the agent.

Coming up next: And if the ticket changes hands after you checked it?

An entry you checked can change owner

IN SHORT The token can be transferred, so an entry can change hands after you vetted it.

THE SAME AGENTID, A MONTH APART

When you vetted it

  • Owner: the operator you checked
  • Payment wallet: set

After a transfer

  • Owner: someone new, and a Transfer event on-chain
  • Payment wallet: cleared to zero
Illustrative. What the Draft changes on a transfer, and what you would see.

The Draft clears agentWallet, the payment wallet, on transfer; setting a new one needs a signature from that wallet. So a zero wallet on an agent that used to have one is a signal to re-check, and so is a Transfer event since your last review.

ITEM GET

Re-check after any Transfer

A Transfer event or a cleared payment wallet since your last review means the operator may have changed.

Coming up next: Could the entry’s reviews tell you whom to trust?

Reputation scores need reviewers you trust

IN SHORT A reputation score helps only when filtered by reviewers you already trust: the Draft warns that fakes are possible.

ERC-8004 also defines a Reputation Registry. Its getSummary function needs a non-empty list of client addresses, and the Draft says why: unfiltered results “are subject to Sybil/spam attacks.”

Its security section adds that “Sybil attacks are possible, inflating the reputation of fake agents.” A Sybil attack One actor running many fake identities, here fake reviewers, to push a score up or down. See the glossary is one actor running many fake reviewers.

WHICH SCORE TO READ
Decide: Whose reviews make up the score?Decision tree: Whose reviews make up the score? If Reviewers you already trust, then Use it as one signal. If Everyone, unfiltered, then Ignore it.DECIDEWhose reviews make up thescore?If reviewers you alreadytrustUse it as one signalStill not proof the agentmay actIf everyone, unfilteredIgnore itExposed to Sybil attacks
My reading of the Draft’s warning, not a rule it sets.

ADAM says: An average score across everyone can be pumped up by fake reviewers.

We made the same split in ERC-3643. An ONCHAINID identity contract proves nothing by existing; what counts is the claims on it, signed by issuers in the token’s Trusted Issuers Registry, for the claim topics that token requires.

ERC-8004’s registry plays the identity contract.

Who you accept claims from is still your call, and for agents it has no standard answer yet.

FAQ

No. ERC-8004, Trustless Agents, has status Draft in the ethereum/ERCs repository, created 13 August 2025, with a discussion on Ethereum Magicians. Its fields and functions can still change, and I’m not one of its authors.

The card is a JSON file the agent’s server publishes: skills, interfaces, security schemes, maybe a JWS signature. An ERC-8004 entry is an ERC-721 token in an on-chain registry, pointing to a file that can list the card. The card says what the agent offers; the entry gives it an on-chain handle with an owner.

Sources, re-read on 7 October 2026: ERC-8004 (Draft), ERC-8004 discussion. Not legal advice.

STAGE CLEAR

What you now know

  • An ERC-8004 entry names who registered an agent, who owns it now and where its file is.
  • The entry can change owner, so a Transfer or a cleared wallet means re-check.
  • A reputation score counts only when filtered by reviewers you already trust.

Check yourself

Tap or click a question to see the answer.

An agent’s entry shows a high average score from thousands of reviewers you’ve never heard of. Does that raise your trust?

No. Unfiltered, that score is exposed to Sybil attacks: one actor can run many fake reviewers.

Next stage:How do you prove an Agent Card and an ERC-8004 entry belong to the same agent?6 min
Adam Boudjemaa
Adam Boudjemaa

Web3 x AI engineer, former CTO of Integra. Named author (1 of 5) of ERC-3643, first author of ERC-6960, co-author of ERC-7410, and co-author of ERC-8203, which is still a draft.

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