# SignCheck Lite by AgentGate

> SignCheck Lite by AgentGate is a paid API for AI agents from api.youraitools.co, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-23).

Offline (no RPC) pre-sign safety check that decodes transactions, EIP-712 typed data, and x402 payment payloads, returning a SAFE/CAUTION/DANGER verdict with risk flags and OFAC SDN screening.

## Facts

- Endpoint: GET https://api.youraitools.co/signcheck/v1/lite?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signcheck-lite-by-agentgate-0884877f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ep82DdsTtVxFDzuh4czxx

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 signcheck-lite-by-agentgate-0884877f
```

Example prompt: Before I sign this token approval transaction, can you run a SignCheck Lite safety scan on it? The transaction is on Base, going to 0x3c1A1E01e790Cd326495631B3b38Bd7068F08d6F, with this calldata: 0x095ea7b3000000000000000000000000...

## When to prefer this

Use SignCheck Lite when you need a fast, offline pre-sign risk assessment with no RPC dependency — ideal for agent wallets that must screen transactions before signing without incurring latency from on-chain calls. Prefer this over /v1/check when speed matters more than live on-chain state, or when you want OFAC screening and decoded risk flags without simulation. Use /v1/check instead when you need actual on-chain facts or transaction simulation results.

## Known failure modes

- Missing required 'to' query parameter returns validation error
- Malformed or non-hex 'data' field causes decoding failure
- Unsupported chain identifier returns chain resolution error
- Ambiguous or empty payload may return low-confidence partial decode
- OFAC list may have a staleness lag if not refreshed recently
- No on-chain simulation in /lite — use /v1/check for live state verification

## How this service works

Offline transaction and signature safety check API for crypto wallets. Offline pre-sign check (no RPC, fast): decodes a transaction, EIP-712 typed data (Permit, Permit2, EIP-3009), an EIP-7702 authorization or an x402 402 + payment payload and returns SAFE/CAUTION/DANGER, every risk flag with its reason, decoded args, counterparties, x402 payment-vs-402 match and OFAC SDN screening. Use /v1/check for on-chain facts and simulation.

## Output

A JSON object containing: a verdict tier (SAFE/CAUTION/DANGER), an array of risk flags each with a code, human-readable message, and severity level, a numeric risk score, the decoded action type (e.g. erc20_approve), identified counterparties with their roles and addresses, OFAC SDN screening results with match count and list date, decoded token metadata, and a plain-English summary of what the transaction does.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "to"
     ],
     "properties": {
      "to": {
       "type": "string",
       "description": "tx.to"
      },
      "data": {
       "type": "string",
       "description": "tx.data (0x hex)"
      },
      "from": {
       "type": "string",
       "description": "tx.from (enables simulation)"
      },
      "chain": {
       "type": "string",
       "description": "base (default), ethereum, base-sepolia or a chain id"
      },
      "value": {
       "type": "string",
       "description": "tx.value in wei"
      }
     },
     "description": "Search intents: decode transaction, signature risk check, permit2 decoder, eip712 safety, wallet security api, approve risk check"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "kind": {
       "type": "string"
      },
      "tier": {
       "type": "string"
      },
      "chain": {
       "type": "object"
      },
      "flags": {
       "type": "array"
      },
      "action": {
       "type": "string"
      },
      "engine": {
       "type": "string"
      },
      "onchain": {
       "type": "object"
      },
      "summary": {
       "type": "string"
      },
      "verdict": {
       "type": "string"
      },
      "sanctions": {
       "type": "object"
      },
      "risk_score": {
       "type": "number"
      },
      "counterparties": {
       "type": "array"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "kind": "transaction",
  "tier": "full",
  "chain": {
   "id": 8453,
   "name": "Base"
  },
  "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"
   }
  ],
  "action": "erc20_approve",
  "engine": "signcheck-0.1",
  "onchain": {
   "block": 52942270,
   "chain": "Base",
   "tokens": [
    {
     "name": "USD Coin",
     "symbol": "USDC",
     "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
     "decimals": 6
    }
   ],
   "available": true,
   "simulation": {
    "success": true
   }
  },
  "summary": "Approve 0x3c1A…8d6F to spend UNLIMITED USDC from your wallet",
  "verdict": "DANGER",
  "sanctions": {
   "list": "US Treasury OFAC Specially Designated Nationals (SDN) list",
   "matches": 0,
   "list_date": "2026-10-21",
   "evm_addresses": 124
  },
  "risk_score": 75,
  "counterparties": [
   {
    "type": "eoa",
    "label": null,
    "roles": [
     "spender"
    ],
    "address": "0x3c1A1E01e790Cd326495631B3b38Bd7068F08d6F"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signcheck-lite-by-agentgate-0884877f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.youraitools.co](https://www.zero.xyz/host/api.youraitools.co/llms.txt)