Signcheck Check
by SignCheck by AgentGate in Onchain & crypto
Transaction and signature safety check API for crypto wallets. Pre-sign safety check for agent wallets: send a transaction, EIP-712 typed data (Permit, Permit2, EIP-3009, Seaport), an EIP-7702 authorization, or an x402 402 + payment payload. Returns SAFE/CAUTION/DANGER, a plain-English summary and every risk flag (unlimited or EOA approvals, setApprovalForAll, fake USDC domains, x402 overpay, OFAC SDN) plus on-chain facts and eth_call simulation.
https://api.youraitools.co/signcheck/v1/check- Price
- $0.015
- per call in USDC
- Uptime
- 100%
- last 30 days
- Response time
- 47 ms
- 161 ms slowest 5%
- Last check
- Passed
- 1 h ago, next any minute now
Reliability
Status and outage history · Atom feed · Watch with other listings
How to call it
GET https://api.youraitools.co/signcheck/v1/check
Each call costs $0.015 in USDC on Polygon, paid with the request over x402.
Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.
Example request
From the listing.
GET https://api.youraitools.co/signcheck/v1/check?chain=base&data=0x095ea7b30000000000000000000000003c1a1e01e790cd326495631b3b38bd7068f08d6fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0xE35E10429048b6F3409b0307E65e4797477Ed144&to=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
chain | string | No | base (default), ethereum, base-sepolia or a chain id |
data | string | No | tx.data (0x hex) |
from | string | No | tx.from (enables simulation) |
to | string | Yes | tx.to |
value | string | No | tx.value in wei |
Example response
The provider's example. We can't check it without paying.
Example response, 57 lines
{
"action": "erc20_approve",
"chain": {
"id": 8453,
"name": "Base"
},
"counterparties": [
{
"address": "0x3c1A1E01e790Cd326495631B3b38Bd7068F08d6F",
"label": null,
"roles": [
"spender"
],
"type": "eoa"
}
],
"engine": "signcheck-0.1",
"flags": [
{
"code": "SPENDER_IS_EOA",
"message": "The token allowance goes to 0x3c1A…8d6F, a plain wallet (no contract code). Legitimate apps approve contracts; approvals to wallets are how drainer kits steal funds.",
"severity": "critical"
},
{
"code": "UNLIMITED_APPROVAL",
"message": "Grants an UNLIMITED allowance to 0x3c1A…8d6F.",
"severity": "medium"
}
],
"kind": "transaction",
"onchain": {
"available": true,
"block": 52942270,
"chain": "Base",
"simulation": {
"success": true
},
"tokens": [
{
"address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"decimals": 6,
"name": "USD Coin",
"symbol": "USDC"
}
]
},
"risk_score": 75,
"sanctions": {
"evm_addresses": 124,
"list": "US Treasury OFAC Specially Designated Nationals (SDN) list",
"list_date": "2026-10-21",
"matches": 0
},
"summary": "Approve 0x3c1A…8d6F to spend UNLIMITED USDC from your wallet",
"tier": "full",
"verdict": "DANGER"
}Call it from code
The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.015.
curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://api.youraitools.co/signcheck/v1/check?chain=base&data=0x095ea7b30000000000000000000000003c1a1e01e790cd326495631b3b38bd7068f08d6fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0xE35E10429048b6F3409b0307E65e4797477Ed144&to=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913'
# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://api.youraitools.co/signcheck/v1/check?chain=base&data=0x095ea7b30000000000000000000000003c1a1e01e790cd326495631b3b38bd7068f08d6fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0xE35E10429048b6F3409b0307E65e4797477Ed144&to=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913' \
| grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decodeJavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";
// Pays at most $0.015 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.015" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);
// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.015 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.youraitools.co%2Fsigncheck%2Fv1%2Fcheck
const res = await pay("https://api.youraitools.co/signcheck/v1/check?chain=base&data=0x095ea7b30000000000000000000000003c1a1e01e790cd326495631b3b38bd7068f08d6fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0xE35E10429048b6F3409b0307E65e4797477Ed144&to=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913");
console.log(res.status, await res.text());Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client
# Pays at most $0.015 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.015"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))
with x402_requests(client) as session:
res = session.get("https://api.youraitools.co/signcheck/v1/check?chain=base&data=0x095ea7b30000000000000000000000003c1a1e01e790cd326495631b3b38bd7068f08d6fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0xE35E10429048b6F3409b0307E65e4797477Ed144&to=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913")
print(res.status_code, res.text)Security scan
No findings
We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.
Recent checks
| When | Result | HTTP | Time | Price |
|---|---|---|---|---|
| 1 h ago | Passed | 402 | 124 ms | $0.015 |
| 9 h ago | Passed | 402 | 44 ms | $0.015 |
| 17 h ago | Passed | 402 | 47 ms | $0.015 |
| 24 h ago | Passed | 402 | 32 ms | $0.015 |
| 32 h ago | Passed | 402 | 43 ms | $0.015 |
Show 9 older checks
| 39 h ago | Passed | 402 | 161 ms | $0.015 |
| 47 h ago | Passed | 402 | 147 ms | $0.015 |
| 2 days ago | Passed | 402 | 104 ms | $0.015 |
| 3 days ago | Passed | 402 | 52 ms | $0.015 |
| 3 days ago | Passed | 402 | 138 ms | $0.015 |
| 3 days ago | Passed | 402 | 13 ms | $0.015 |
| 3 days ago | Passed | 402 | 113 ms | $0.015 |
| 4 days ago | Passed | 402 | 19 ms | $0.015 |
| 4 days ago | Passed | 402 | 22 ms | $0.015 |