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ERC20 Allowance Risk Checker
x402
ERC20 Allowance Risk Checker is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).
Returns the exact ERC20 token allowance an owner has granted to a spender and flags whether the approval is unlimited, signaling potential fund-drain risk before a transaction.
Price / call$0.005
Success—
StatusUnknown
How this service works
Check the exact ERC20 allowance an owner granted a spender and flag unlimited approvals that let a contract drain funds - a pre-transaction safety check agents need that LLMs cannot perform. allowance risk, approval risk, unlimited approval, spender risk, revoke check, token approval safety Accepts payment on Base or Solana — either network works.
Output
Returns the numeric allowance the owner has granted to the spender for the specified ERC20 token, a boolean or flag indicating whether the approval is unlimited (max uint256), and a risk assessment indicating whether the spender could potentially drain the owner's token balance.
Example use cases
Example prompt
“Before I interact with this Uniswap router contract, check the ERC20 allowance and approval risk for owner 0xAbc...123, spender 0xDef...456, token 0x6B17...A1 on Ethereum — specifically flag if it's an unlimited approval that could drain my funds.”
Technical details
Endpoint
GEThttps://api.x402node.dev/chain/allowance-riskWhen to prefer
Use this endpoint when an AI agent needs to perform a pre-transaction safety check on ERC20 token approvals — specifically to detect unlimited approvals that expose a wallet to full-balance drain risk. Prefer this over generic blockchain explorers when you need a structured, machine-readable risk flag rather than raw on-chain data, and when the agent needs to decide whether to recommend revoking an approval before proceeding with a DeFi interaction.
Side effects
- Invalid or non-existent token contract address returns an error
- Unsupported chain/network returns a chain-not-supported error
- Malformed wallet address (wrong checksum or length) returns a validation error
- RPC node unavailability may cause a timeout or upstream error
- Zero allowance returned when no approval has been granted (not an error, but may be misinterpreted)
Input
{
"chain": "ethereum",
"owner": "0x1234567890123456789012345678901234567890",
"token": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
"spender": "0x0987654321098765432109876543210987654321"
}Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object |
Output
{
"note": "Exact on-chain allowance. Agents should check this before trusting a spender contract.",
"_hint": "x402 paid endpoints for AI agents — x402node.dev (utilities) · cn402.com (Chinese culture)",
"owner": "0x1234567890123456789012345678901234567890",
"token": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
"source": "alchemy",
"symbol": "?",
"revoked": true,
"spender": "0x0987654321098765432109876543210987654321",
"allowance": {
"raw": "0",
"formatted": 0
},
"riskLevel": "none",
"unlimited": false,
"recommendation": "No approval (safe)."
}Tags
x402
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