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Base ERC-20 Token Allowance Lookup
x402
Base ERC-20 Token Allowance Lookup is a paid API for AI agents from agent-data-tools.revmesh2074.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-14).
Returns the current ERC-20 token allowance (approved spending limit) that a spender address has been granted by an owner wallet on Base mainnet.
Price / call$0.002
Success—
StatusUnknown
How this service works
Read public static documentation as text or Markdown with code, tables, headings and links for $0.002 USDC on Base via x402. Inspect real cached examples and an unsigned quote, then buy with a capped Node CLI. No account or API key. No JavaScript rendering, authenticated or paywalled access. Other paid utilities remain available.
Output
Returns a JSON object with the chain name ('base'), owner address, token contract address, token symbol, spender address, whether any approval exists (approved boolean), raw allowance in base units, formatted allowance as a human-readable string, token decimals, and a flag indicating whether the approval is unlimited (unlimited boolean).
Example use cases
Pre-swap approval check for DeFi bot
“Before I execute this Uniswap swap, check if my wallet 0xAbCd...1234 has already approved the Uniswap Permit2 router 0x000000000022D473030F116dDEE9F6B43aC78BA3 to spend USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base — and tell me how much.”
Audit unlimited token approvals
“I want to know if my wallet 0xAbCd...1234 has granted an unlimited allowance to the Aave lending pool contract 0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2 for WETH (0x4200000000000000000000000000000000000006) on Base.”
DeFi security review for risky approvals
“Check what allowance the suspicious contract at 0xDead...Beef has to spend my USDC from wallet 0x1234...5678 on Base — I want to know if it's unlimited or any specific amount.”
Technical details
Endpoint
GEThttps://agent-data-tools.revmesh2074.workers.dev/base-allowance?utm_source=zero.xyzWhen to prefer
Use this endpoint when an AI agent needs to check ERC-20 token spending permissions on Base mainnet without running its own blockchain node or holding an API key. It is ideal for pre-transaction validation in DeFi workflows (confirming a router can spend tokens before swapping), security audits of wallet approvals, or any agent pipeline that needs real-time on-chain allowance data for a fraction of a cent per call via x402 USDC micropayment.
Side effects
- Invalid or malformed wallet/contract address returns an error
- Token address is not a valid ERC-20 contract on Base — may return empty or error response
- Spender address with no approval returns allowance '0' and approved: false (not an error)
- Network or RPC timeout causes a failed lookup
- Payment failure (insufficient USDC balance or allowance for x402 fee) prevents the request
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"chain": "base",
"owner": "0x4200000000000000000000000000000000000006",
"token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"symbol": "USDC",
"spender": "0x000000000022D473030F116dDEE9F6B43aC78BA3",
"approved": false,
"decimals": 6,
"allowance": "0",
"unlimited": false,
"allowanceFormatted": "0"
}
}Tags
x402
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