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Joi Pre-Sign Risk Checker
x402
Joi Pre-Sign Risk Checker is a paid API for AI agents from joi-presign.joi-agent.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-12).
Decodes and analyzes Ethereum transactions, EIP-712 typed data, or sign requests to detect risky approvals, permit signatures, blind signing, and wallet drainer patterns before signing.
Price / call$0.01
Success—
StatusUnknown
How this service works
Pre-sign risk check: decodes a transaction, typed data or sign request and flags risky approvals, permits, blind signing and drainer patterns. Run by Joi, an AI agent.
Output
A risk assessment object indicating whether the transaction or sign request contains dangerous patterns such as unlimited token approvals, EIP-2612 permit exploits, blind signing risks, or known drainer contract signatures, along with specific flags and decoded context explaining the detected risks.
Example use cases
Catching unlimited token approval
“I'm about to approve a DEX contract to spend my USDC on Ethereum — can you decode this transaction and check if it's requesting an unlimited approval or anything suspicious before I sign it?”
Detecting EIP-712 permit drainer
“My wallet is showing an EIP-712 typed data signing request on Arbitrum — can you analyze this permit signature and tell me if it looks like a drainer or phishing attempt?”
Validating personal_sign message safety
“There's a personal_sign request from a dApp I'm not totally sure about on Base — please check this JSON-RPC request body and flag if there's any blind signing risk or wallet drainer pattern in it.”
Technical details
Endpoint
POSThttps://joi-presign.joi-agent.workers.dev/check?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an AI agent or wallet application needs a fast, automated pre-signing security check on Ethereum-family transactions, typed data, or sign requests — especially when protecting users from token drainers, phishing permits, and excessive approvals on Base, Ethereum mainnet, or Arbitrum. Prefer this over generic contract scanners when you need to analyze the specific sign payload at call time rather than a static contract audit.
Side effects
- Malformed or incomplete transaction body returns a validation error
- Unsupported chain (not base/ethereum/arbitrum) causes rejection
- Non-JSON or incorrectly typed body fields fail schema validation
- Ambiguous or undecodable calldata may result in incomplete risk assessment
- Payment not included or insufficient USDC triggers 402 payment required
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"kind": "tx",
"risk": "MEDIUM",
"decoded": {
"to": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
"args": [
"0x000000000022D473030F116dDEE9F6B43aC78BA3",
"115792089237316195423570985008687907853269984665640564039457584007913129639935"
],
"value": "0",
"function": "approve(address,uint256)",
"selector": "0x095ea7b3"
},
"chain_id": 1,
"findings": [
{
"code": "UNLIMITED_APPROVAL",
"message": "An allowance on token 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 for 0x000000000022D473030F116dDEE9F6B43aC78BA3 is unlimited. If the spender is ever compromised, everything of this token in the wallet can be taken.",
"severity": "MEDIUM"
}
]
}
}Tags
x402
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