x402 on Stellar

Every x402 endpoint that takes USDC on Stellar, checked once a day by x402 Doctor the way a paying agent would, plus what Stellar itself (Horizon) says about the seller's payout account. Read-only: it stops at the 402 challenge and never pays. x402 Doctor's own paid checks take USDC on Stellar too, with sponsored fees.

Today

What kind of services

A seller often lists the same API many times (once per coin, city or ticker). Endpoints of one seller with nearly the same description count as one service here; the kind of service is judged by TypeSafe Jev (a keyword guess until Jev has seen it).

Sellers

Seller	Endpoints	Services	Payable

Endpoints

What is checked on Stellar

As the x402 Stellar client (@x402/stellar, "exact" with a Soroban token transfer) checks it before it signs:

• The USDC trustline. A Stellar account (G…) can only receive USDC once it has a trustline to Circle's USDC. A payout account without one, or one that was never funded, makes every payment fail, so Doctor asks Horizon for every endpoint. A contract (C…) needs no trustline.
• The USDC contract. The asset must be a Soroban token contract (C…): USDC on Stellar is CCW67TSZV3SSS2HXMBQ5JFGCKJNXKZM7UQUWUZPUTHXSTZLEO7SJMI75 (testnet CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA). "USDC" or "USDC:G…" is refused by the client.
• Sponsored fees. extra.areFeesSponsored must be true: the facilitator rebuilds and submits the transaction and pays its fee, and the client refuses an option without it.
• The transfer can be signed. A valid payTo (G…, C… or M…, with its checksum) and an atomic integer amount (USDC has 7 decimals on Stellar: 100000 is $0.01).
• 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).

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