# AgentResolver EIP-712 Hash Computation

> AgentResolver EIP-712 Hash Computation is a paid API for AI agents from agentresolver.vercel.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-19).

Computes an EIP-712 structured data hash from typed domain, message, and primary type inputs for use in x402 payment signing flows

## Facts

- Endpoint: POST https://agentresolver.vercel.app/api/eip712-hash
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentresolver-eip-712-hash-computation-32968905
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sU_MxAx4UFQl4J-yTlQ8a

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 agentresolver-eip-712-hash-computation-32968905 -d '<json body>'
```

Example prompt: Can you compute the EIP-712 hash for my payment authorization message? The primaryType is 'Payment', the domain includes name 'x402' and chainId 8453, and my message has recipient, amount, and nonce fields.

## When to prefer this

Use this endpoint when you need to compute a deterministic EIP-712 structured data hash from raw typed data components — especially in x402 payment preflight flows on Base or Solana where you need a signable digest before submitting a payment authorization. Prefer this over local computation when you want a trusted, hosted EIP-712 encoder without implementing the ABI encoding yourself.

## Known failure modes

- Missing or malformed primaryType returns a validation error
- Mismatched types definition and message fields cause hash computation failure
- Invalid domain object structure results in encoding error
- Empty or null message object returns an error response
- Malformed JSON body returns HTTP 400

## How this service works

Verify an x402 endpoint before paying: live payTo, USDC quote, network, asset, resource binding, TLS and endpoint safety for $0.001 on Base or Solana.

## Output

Returns a JSON object containing the computed EIP-712 structured data hash (digest) derived from the provided types, domain, message, and primaryType — ready to be signed by a wallet or used in payment verification flows.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "types": {
   "type": "object"
  },
  "domain": {
   "type": "object"
  },
  "message": {
   "type": "object"
  },
  "primaryType": {
   "type": "string",
   "maxLength": 128,
   "minLength": 1
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {}
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentresolver-eip-712-hash-computation-32968905/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentresolver.vercel.app](https://www.zero.xyz/host/agentresolver.vercel.app/llms.txt)