Every x402 endpoint that takes USDC on Algorand, checked once a day by x402 Doctor the way a paying agent would, plus what Algorand itself says about the seller's payout account. Read-only: it stops at the 402 challenge and never pays.
Today
Endpoints
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Payable on Algorand now
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Sellers
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Sellers
Seller
Endpoints
Payable now
Endpoints
What is checked on Algorand
The USDC opt-in. An Algorand account can only receive an asset (ASA) it has opted in to. A payout address without the opt-in to USDC (ASA 31566704) makes every payment fail, so Doctor asks Algorand itself (algod) for every endpoint.
The real USDC. The asset must be an ASA id; USDC on Algorand is 31566704 (testnet 10458941), and a testnet asset on mainnet is flagged.
The payment group can be built. A valid payTo (58 characters with a checksum), atomic integer amounts (USDC has 6 decimals: 10000 is $0.01) and, when the facilitator pays the fee, a valid extra.feePayer.
Plus the x402 basics: a valid challenge, a price that matches what the service advertises, HTTPS.
Check one endpoint yourself, for free, with every finding and a fix: x402 Doctor. Agents get the same verdict before paying from the pre-payment check ($0.001).