> ## Documentation Index
> Fetch the complete documentation index at: https://a-identity.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# ERC-8004

> Trustless Agents. Portable on-chain identity, reputation, and validation.

ERC-8004, titled **Trustless Agents**, is a draft Ethereum standard for agent
identity, reputation, and validation. A-Identity reads from **live ERC-8004
registries deployed on Circle Arc testnet** (Identity `0x8004A818…BD9e`, Reputation
`0x8004B663…8713`, Validation `0x8004Cb1B…4272`), so an agent can prove who it is to
anyone, with no central marketplace acting as gatekeeper.

## Three Registries

| Registry   | What It Holds                                                                        | A-Identity Uses It For    |
| ---------- | ------------------------------------------------------------------------------------ | ------------------------- |
| Identity   | A portable agent id as an ERC-721 token whose tokenURI points to a registration file | Resolving who an agent is |
| Reputation | Standardized feedback on settled work                                                | The reputation score      |
| Validation | Cryptographic or economic proof that work was done                                   | Higher-trust checks       |

## How An Agent Is Identified

An agent's identity is an ERC-721 token. The token URI points to a registration
file (JSON) that describes the agent, served over HTTPS or stored on IPFS. Because
it is an NFT, it is portable, transferable, and indexable with tooling that already
exists.

```json Registration file (shape) theme={null}
{
  "name": "Meridian",
  "category": "Research / Data",
  "standard": "ERC-8004",
  "app": "A-Identity"
}
```

## Resolve One Now

Resolve an identity with a **live on-chain read** of Arc's ERC-8004 registry (by agent
id, token id, or owner address). No mocks — it calls `ownerOf` + `tokenURI` for real.

```ts theme={null}
const passport = await identity.resolve("eip155:5042002:8004/849980")
// { found: true, source: "rpc", agent: { agentId, owner, chain: "arc", ... } }
```

<Card title="Reputation Scoring" icon="star" href="/developers/mcp-server">
  Reputation is computed deterministically, so the same history always yields the
  same score. See the MCP server reference.
</Card>