# The Sealer Protocol - Onchain AI Agent Attestation

> The Sealer Protocol - Onchain AI Agent Attestation is a paid API for AI agents from www.thesealer.xyz, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-14).

Issues onchain attestations (statements, cards, sleeves, or SIDs) for AI agents, certified with EIP-712 wallet signatures on Base or Solana.

## Facts

- Endpoint: POST https://www.thesealer.xyz/api/attest
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/the-sealer-protocol-onchain-ai-agent-attestation-3c90e9d6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ehI1akIDhYAzXc3II-wuE

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability the-sealer-protocol-onchain-ai-agent-attestation-3c90e9d6 -d '<json body>'
```

Example prompt: Issue an onchain 'statement' attestation for my AI agent — wallet address 0xAbC123..., entity type AI_AGENT — with the statement 'I completed the swap on behalf of the user' on Base, signed with my EIP-712 signature and nonce 1716230400.

## When to prefer this

Use this endpoint when an AI agent needs to create a verifiable, onchain credential or identity record tied to a specific wallet address. It is the right choice when accountability, provenance, or certification of agent actions is required on Base or Solana, particularly when you need a tamper-proof statement or identity artifact (SID, card, sleeve) signed by the agent itself.

## Known failure modes

- Expired nonce — agentNonce timestamp is more than 5 minutes old, returns 400/401
- Invalid EIP-712 signature — agentSig does not match agentId wallet, returns 401
- Unsupported chain — chain value not in [Base, Solana], returns 400
- Missing required fields — agentId, agentSig, agentNonce, or format absent, returns 422
- Payment failure — x402 payment of 0.1 USDC not confirmed, returns 402
- Non-HTTPS imageUrl — image URL uses HTTP instead of HTTPS, returns 400

## How this service works

Onchain accountability for AI agents. Commit, prove, get certified.

## Output

A certified onchain attestation record for the AI agent, in the requested format (statement, card, sleeve, or SID), anchored to the agent's wallet identity and recorded on Base or Solana.

## Request schema (JSON Schema)

```json
{
 "properties": {
  "input": {
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "format",
      "agentId",
      "agentSig",
      "agentNonce"
     ],
     "properties": {
      "format": {
       "type": "string"
      },
      "agentId": {
       "type": "string",
       "description": "EVM: your 0x wallet. Solana: your base58 public key."
      },
      "agentSig": {
       "type": "string",
       "description": "EIP-712 signature from your wallet proving ownership (EVM only)"
      },
      "agentNonce": {
       "type": "string",
       "description": "Unix timestamp (seconds) used when signing"
      },
      "statement": {
       "type": "string"
      },
      "theme": {
       "type": "string"
      },
      "imageUrl": {
       "type": "string"
      }
     }
    }
   }
  },
  "output": {
   "properties": {
    "example": {
     "status": "success",
     "txHash": "0xabc",
     "uid": "abc123",
     "permalink": "https://thesealer.xyz/c/abc123"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/the-sealer-protocol-onchain-ai-agent-attestation-3c90e9d6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.thesealer.xyz](https://www.zero.xyz/host/www.thesealer.xyz/llms.txt)