x402 on Stellar: 631 paid endpoints, one big seller, and one mistake that blocks 7%.

Frits Zwager, Fizzl · data from the scan of 17 October 2026 · every Stellar endpoint, live

x402 lets an API ask for payment with an HTTP 402 Payment Required answer, so an AI agent can pay per call in stablecoins. On Stellar the agent pays in USDC through a Soroban token transfer that it signs, and a facilitator such as OpenZeppelin's Built on Stellar settles it and pays the network fee. x402 Doctor checks every paid endpoint it can find, every day, the way a paying agent would. This is what it sees on Stellar.

1. One seller is almost the whole market

The 631 endpoints come from 6 sellers and 599 distinct services. One seller, agent402.tools, has 577 of them (91%), for 545 different tools: developer utilities, crypto and finance data, on-chain lookups and more. The other five have 40, 7, 5, 1 and 1 endpoints.

For an agent that wants to pay on Stellar, that means one seller's uptime and pricing decide almost everything it can buy there today. The per-endpoint detail, with every seller, is public on the Stellar page.

2. Stellar is always the second way to pay

Every Stellar endpoint we checked also accepts USDC on Base. agent402.tools offers as many as 13. No seller offers Stellar alone.

Measured against the whole market, Stellar is small: of the 50,373 paid endpoints that answered on 17 October, 577 could be paid on Stellar that day, about 1%. Base was on 47,074, Solana on 10,127, Algorand on 2,372 and the XRP Ledger on 1,861.

And it hasn't grown with the market yet. On 23 September 596 Stellar endpoints were listed, on 17 October 624. In the same weeks the whole market grew from about 16,600 endpoints to over 50,000.

3. One mistake blocks 7%

47 of the 631 endpoints (7%), from 3 sellers, can't be paid on Stellar. All 47 fail for the same reason: the 402 names the asset as text, "USDC" or "USDC:GA5Z…KZVN" (the classic asset code with its issuer), instead of the address of the USDC token contract. The official @x402/stellar client refuses such an offer with "Invalid Stellar asset address", so an agent never gets to pay.

Because these endpoints also accept Base, the sellers may never notice: their Base customers pay fine. An agent that only holds USDC on Stellar can't buy from them.

The fix is one field. On Stellar mainnet, x402's exact scheme pays with the USDC Stellar Asset Contract, and amounts use its 7 decimals:

{
  "scheme": "exact",
  "network": "stellar:pubnet",
  "asset": "CCW67TSZV3SSS2HXMBQ5JFGCKJNXKZM7UQUWUZPUTHXSTZLEO7SJMI75",
  "amount": "10000",
  "payTo": "G… your account, with a USDC trustline",
  "extra": { "areFeesSponsored": true }
}

"10000" is $0.001. areFeesSponsored comes from the facilitator: with it, the agent doesn't need XLM for the fee. The payout account needs a USDC trustline, or the transfer fails. None of the 631 endpoints failed on the trustline or the payout address; the asset field was the only problem we found.

4. Prices: cheaper than the rest of x402

The median Stellar endpoint costs $0.003 per call, against $0.01 for x402 as a whole. 188 endpoints (30%) cost $0.001, and 486 (77%) cost $0.01 or less. 17 cost more than $0.10, the most expensive $19.99.

5. What's for sale

Categories come from an AI read of each service's own description (TypeSafe Jev).

What would help Stellar grow

• Discovery. Agents find x402 services through discovery lists. On 17 October no Stellar facilitator published a mainnet list yet, so most Stellar endpoints are found through lists built for Base, such as the CDP Bazaar.
• The asset field. The one mistake above is easy to fix and easy to test: a free check shows it before any agent tries to pay.
• More sellers. With one seller holding 91%, every new seller that adds Stellar next to Base widens what an agent can buy there.

How we measure

• Sources: the CDP Bazaar, Circle's Agent Marketplace, the MPP directory, GoPlausible and other public x402 indexes, read every day.
• The Stellar check: each endpoint is called once without paying. For a Stellar offer x402 Doctor checks that the payout address is a valid Stellar address (with its checksum), that the asset is a token contract, that the amount fits the token's 7 decimals, whether fees are sponsored, and that the payout account holds a USDC trustline (read from Horizon). Nothing is paid.
• Counts: the 631 endpoints are those that offered Stellar on any day of the last 25. Payable means the Stellar offer itself can be paid today; an endpoint can be payable on Base and still not on Stellar.
• Disclosure: Fizzl's own services (x402 Doctor, presign-guard and Ichimoku Signal) started accepting USDC on Stellar on 17 October 2026. They are not in these numbers.

Check a Stellar endpoint yourself

• Sellers: the free web check reads your 402 and shows the Stellar problems with the fix.
• Agents: before paying, GET https://x402-doctor.fizzl.eu/api/v1/preflight?url=… answers go, caution or no_go for $0.001, payable in USDC on Stellar too. Every Stellar endpoint and its status: x402-doctor.fizzl.eu/stellar, or as JSON: GET https://x402-doctor.fizzl.eu/api/trust/network?network=stellar.
• The whole x402 market, not just Stellar: We check 50,000 paid x402 endpoints every day.