# PayAI EIP-712 Signature Safety Screener

> PayAI EIP-712 Signature Safety Screener is a paid API for AI agents from payai.agentstools.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Pre-signs safety verdict for off-chain EIP-712 signatures (EIP-2612, Permit2, EIP-3009), decoding authorization details and returning allow/warn/block with a 0-100 risk score.

## Facts

- Endpoint: POST https://payai.agentstools.dev/tx/signature
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/payai-eip-712-signature-safety-screener-59c460d9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_S0TX7IB29uWknum-7UQBo

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 payai-eip-712-signature-safety-screener-59c460d9 -d '<json body>'
```

Example prompt: Before I sign this Permit2 typed-data message on Base, can you screen it for safety — decode what it's authorizing (spender, token, amount, deadline) and tell me if it's safe to sign or if I should block it?

## When to prefer this

Choose this endpoint when you need a pre-signing safety check specifically for off-chain EIP-712 token-approval signatures (Permit2, EIP-2612, EIP-3009) on EVM chains. It is purpose-built for wallet agents and DeFi workflows that must screen authorization scope, deadline, spender legitimacy, and domain spoofing before a user signs — not for on-chain transaction simulation or general smart contract auditing.

## Known failure modes

- Malformed or invalid EIP-712 typed-data object causes parsing failure
- Unsupported signature type (non-Permit2/EIP-2612/EIP-3009) may return incomplete decode
- Unknown or unlisted spender address yields a warn rather than definitive block
- Signature recovery fails if the provided 0x signature is invalid or truncated
- Network enum value outside supported chains (base, ethereum, arbitrum, optimism, polygon, bnb) rejected

## How this service works

Pre-sign safety verdict for an off-chain EIP-712 signature (EIP-2612, Permit2, EIP-3009). Decodes what it authorizes (spender, token, amount, deadline), checks domain-spoof, approval-hygiene and scam-blocklist, returns allow, warn or block plus a 0-100 risk. Risk indicators, not advice.

## Output

Returns a verdict of allow, warn, or block; a numeric risk score from 0 to 100; decoded authorization details including spender address, token, amount, and deadline; flags for domain spoofing, approval hygiene issues, and scam blocklist hits. These are risk indicators, not financial advice.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "network": {
   "enum": [
    "base",
    "ethereum",
    "arbitrum",
    "optimism",
    "polygon",
    "bnb"
   ],
   "type": "string",
   "description": "EVM network the signature is for (default base)"
  },
  "signature": {
   "type": "string",
   "description": "Optional 0x signature to recover the signer"
  },
  "typed_data": {
   "type": "object",
   "description": "Full EIP-712 typed-data object with domain, primaryType and message"
  },
  "expected_signer": {
   "type": "string",
   "description": "Optional address to compare the recovered signer against"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/payai-eip-712-signature-safety-screener-59c460d9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from payai.agentstools.dev](https://www.zero.xyz/host/payai.agentstools.dev/llms.txt)