# app.certified.signature.proof

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

✓ This is the authoritative definition for this NSID.

## Description

A remote attestation proof record holding the CID of attested content. Lives in the attestor's repository and is referenced from the attested record's `signatures` array via `com.atproto.repo.strongRef`. Conforms to the ATProtocol Attestation Specification.

## Links

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

## Definitions

### `app.certified.signature.proof`

**Type**: `record`

Remote attestation proof containing the CID of the content being attested.

**Key**: `tid`

| Property | Type | Required | Description |
|----------|------|----------|-------------|
| `cid` | `string` (cid) | Yes | CID of the attested content, computed per the ATProtocol Attestation Specification: encode the record with the `signatures` field removed and a temporary `$sig` object inserted (containing `$type` and the housing `repository` DID) as canonical DAG-CBOR, then SHA-256 hash to produce a 36-byte CIDv1. |
| `note` | `string` | No | Optional note explaining the attestation purpose or context. |
| `createdAt` | `string` (datetime) | No | Client-declared timestamp when this proof was created. |

## Raw Schema

```json
{
  "id": "app.certified.signature.proof",
  "defs": {
    "main": {
      "key": "tid",
      "type": "record",
      "record": {
        "type": "object",
        "required": [
          "cid"
        ],
        "properties": {
          "cid": {
            "type": "string",
            "format": "cid",
            "description": "CID of the attested content, computed per the ATProtocol Attestation Specification: encode the record with the `signatures` field removed and a temporary `$sig` object inserted (containing `$type` and the housing `repository` DID) as canonical DAG-CBOR, then SHA-256 hash to produce a 36-byte CIDv1."
          },
          "note": {
            "type": "string",
            "maxLength": 500,
            "description": "Optional note explaining the attestation purpose or context."
          },
          "createdAt": {
            "type": "string",
            "format": "datetime",
            "description": "Client-declared timestamp when this proof was created."
          }
        }
      },
      "description": "Remote attestation proof containing the CID of the content being attested."
    }
  },
  "$type": "com.atproto.lexicon.schema",
  "lexicon": 1,
  "description": "A remote attestation proof record holding the CID of attested content. Lives in the attestor's repository and is referenced from the attested record's `signatures` array via `com.atproto.repo.strongRef`. Conforms to the ATProtocol Attestation Specification."
}
```