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Beggar Bot EIP-3009 Authorization Verifier
x402
Beggar Bot EIP-3009 Authorization Verifier is a paid API for AI agents from beggar-bot-demand.beggarbot.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-11-02).
Validates an EIP-3009 transferWithAuthorization signature against a USDC authorization object on a specified EVM chain
Price / call$0.02
Success—
StatusUnknown
How this service works
Paid: /v1/verify, /v1/risk, /v1/receipt cost $0.01 USDC per call on Base mainnet via x402 (payTo 0x719227f384b66BFEF00093D6d8d32fA9dC2B40e7); utilities analyze Base mainnet (USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) by default, network=base-sepolia optional; /v1/receipt/verify and discovery files are free. Operator: Beggar Bot.
Output
Returns a JSON object indicating whether the EIP-3009 signature is valid, the recovered signer address, and any error details if the signature is invalid or the authorization parameters are malformed.
Example use cases
Pre-flight check before USDC meta-transaction
“Before I broadcast this USDC transferWithAuthorization, verify the EIP-3009 signature is valid on Base mainnet — from 0xSender..., to 0xRecipient..., value 5000000, nonce 0xABCD..., validBefore 1800000000, and signature 0x04ab....”
Validate gasless payment authorization on testnet
“On Base Sepolia, can you verify this EIP-3009 authorization object and signature I received from a user before I accept their payment? From 0xUser..., to 0xMerchant..., value 2000000, nonce 0x9F..., signature 0x78ef....”
Authenticate USDC authorization for cross-chain workflow
“I need to confirm this EIP-3009 USDC authorization signature is legitimate on Arbitrum — authorization has from 0xPayer..., to 0xEscrow..., value 10000000, validAfter 1700000000, validBefore 1800000000, nonce 0xCC..., signature 0xAA12....”
Technical details
Endpoint
POSThttps://beggar-bot-demand.beggarbot.workers.dev/v1/eip3009?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to cryptographically verify an EIP-3009 USDC transferWithAuthorization signature off-chain before submitting it on-chain, or when building payment flows that accept signed USDC authorizations and need to authenticate them cheaply without running your own node. Prefer this over DIY signature recovery when you need multi-chain support (Base, Ethereum, Arbitrum, Optimism, Polygon, Avalanche) and want a simple API call rather than implementing ecrecover and EIP-712 domain hashing yourself.
Side effects
- Invalid or malformed 65-byte signature returns validation failure
- Mismatched authorization fields (wrong chain ID, wrong contract address) cause verification failure
- Expired authorization (validBefore in the past) reported as invalid
- Payment of $0.02 USDC via x402 required per call; missing payment returns 402
- Unsupported chain string returns error
- Nonce already used on-chain may not be detectable without on-chain lookup
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| chain | string | base (default), base-sepolia, ethereum, arbitrum, optimism, polygon, avalanche |
| signature | string | 0x 65-byte signature |
| authorization | object | {from,to,value,validAfter,validBefore,nonce} |
Output
Schema · Response
{
"type": "json"
}Tags
x402
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