# app.certified.link.evm

> Published by [certified.app](https://lexicon.garden/identity/did:plc:apun3uo5jqm34pxzqq6on754)

✓ This is the authoritative definition for this NSID.

## Links

- [View on Lexicon Garden](https://lexicon.garden/lexicon/did:plc:apun3uo5jqm34pxzqq6on754/app.certified.link.evm)
- [Documentation](https://lexicon.garden/lexicon/did:plc:apun3uo5jqm34pxzqq6on754/app.certified.link.evm/docs)
- [Examples](https://lexicon.garden/lexicon/did:plc:apun3uo5jqm34pxzqq6on754/app.certified.link.evm/examples)

## Definitions

### `app.certified.link.evm`

**Type**: `record`

A verifiable link between an ATProto DID and an EVM wallet address, proven via a cryptographic signature. Currently supports EOA wallets via EIP-712 typed data signatures; the proof field is an open union to allow future signature methods.

**Key**: `any`

| Property | Type | Required | Description |
|----------|------|----------|-------------|
| `proof` | `union` | Yes | Cryptographic proof of wallet ownership. The union is open to allow future proof methods (e.g. ERC-1271, ERC-6492). Each variant bundles its signature with the corresponding message format. |
| `address` | `string` | Yes | EVM wallet address (0x-prefixed, with EIP-55 checksum recommended). |
| `createdAt` | `string` (datetime) | Yes | Client-declared timestamp when this record was originally created. |
| `signatures` | `ref` → `app.certified.signature.defs#list` | No | Optional cryptographic signatures attesting to this record's content. The EIP-712 `proof` field proves wallet consent (orthogonal trust statement); `signatures` proves record provenance (e.g. that a platform UI minted this record). |

### `app.certified.link.evm#eip712Proof`

**Type**: `object`

EOA wallet ownership proof via EIP-712 typed data signature. Contains both the structured message that was signed and the resulting signature.

| Property | Type | Required | Description |
|----------|------|----------|-------------|
| `message` | `ref` → `#eip712Message` | Yes | The EIP-712 structured message fields that were signed. |
| `signature` | `string` | Yes | ECDSA signature over the EIP-712 hash (hex-encoded with 0x prefix, 64 or 65 bytes). |

### `app.certified.link.evm#eip712Message`

**Type**: `object`

The EIP-712 typed data message that was signed by the wallet. Contains the fields binding an ATProto DID to an EVM address on a specific chain.

| Property | Type | Required | Description |
|----------|------|----------|-------------|
| `did` | `string` (did) | Yes | The ATProto DID being linked to the EVM address. |
| `nonce` | `string` | Yes | Replay-protection nonce (bigint serialized). |
| `chainId` | `string` | Yes | EVM chain ID as string (bigint serialized). Identifies which chain was used for signing; for EOA wallets the identity link applies across all EVM-compatible chains. |
| `timestamp` | `string` | Yes | Unix timestamp when the attestation was created (bigint serialized). |
| `evmAddress` | `string` | Yes | The EVM wallet address (must match the top-level address field). |

## Raw Schema

```json
{
  "id": "app.certified.link.evm",
  "defs": {
    "main": {
      "key": "any",
      "type": "record",
      "record": {
        "type": "object",
        "required": [
          "address",
          "proof",
          "createdAt"
        ],
        "properties": {
          "proof": {
            "refs": [
              "#eip712Proof"
            ],
            "type": "union",
            "description": "Cryptographic proof of wallet ownership. The union is open to allow future proof methods (e.g. ERC-1271, ERC-6492). Each variant bundles its signature with the corresponding message format."
          },
          "address": {
            "type": "string",
            "maxLength": 42,
            "minLength": 42,
            "description": "EVM wallet address (0x-prefixed, with EIP-55 checksum recommended)."
          },
          "createdAt": {
            "type": "string",
            "format": "datetime",
            "description": "Client-declared timestamp when this record was originally created."
          },
          "signatures": {
            "ref": "app.certified.signature.defs#list",
            "type": "ref",
            "description": "Optional cryptographic signatures attesting to this record's content. The EIP-712 `proof` field proves wallet consent (orthogonal trust statement); `signatures` proves record provenance (e.g. that a platform UI minted this record)."
          }
        }
      },
      "description": "A verifiable link between an ATProto DID and an EVM wallet address, proven via a cryptographic signature. Currently supports EOA wallets via EIP-712 typed data signatures; the proof field is an open union to allow future signature methods."
    },
    "eip712Proof": {
      "type": "object",
      "required": [
        "signature",
        "message"
      ],
      "properties": {
        "message": {
          "ref": "#eip712Message",
          "type": "ref",
          "description": "The EIP-712 structured message fields that were signed."
        },
        "signature": {
          "type": "string",
          "maxLength": 132,
          "minLength": 130,
          "description": "ECDSA signature over the EIP-712 hash (hex-encoded with 0x prefix, 64 or 65 bytes)."
        }
      },
      "description": "EOA wallet ownership proof via EIP-712 typed data signature. Contains both the structured message that was signed and the resulting signature."
    },
    "eip712Message": {
      "type": "object",
      "required": [
        "did",
        "evmAddress",
        "chainId",
        "timestamp",
        "nonce"
      ],
      "properties": {
        "did": {
          "type": "string",
          "format": "did",
          "maxLength": 256,
          "description": "The ATProto DID being linked to the EVM address."
        },
        "nonce": {
          "type": "string",
          "maxLength": 78,
          "minLength": 1,
          "description": "Replay-protection nonce (bigint serialized)."
        },
        "chainId": {
          "type": "string",
          "maxLength": 78,
          "minLength": 1,
          "description": "EVM chain ID as string (bigint serialized). Identifies which chain was used for signing; for EOA wallets the identity link applies across all EVM-compatible chains."
        },
        "timestamp": {
          "type": "string",
          "maxLength": 78,
          "minLength": 1,
          "description": "Unix timestamp when the attestation was created (bigint serialized)."
        },
        "evmAddress": {
          "type": "string",
          "maxLength": 42,
          "minLength": 42,
          "description": "The EVM wallet address (must match the top-level address field)."
        }
      },
      "description": "The EIP-712 typed data message that was signed by the wallet. Contains the fields binding an ATProto DID to an EVM address on a specific chain."
    }
  },
  "$type": "com.atproto.lexicon.schema",
  "lexicon": 1
}
```