x402 data · Circle Gateway · October 2026

Circle's Agent Marketplace: two-thirds of the listings take only Gateway payments.

Frits Zwager, Fizzl · data from Circle's catalog of 19 October 2026 · the x402 Trust Index

Circle's Agent Marketplace lists paid APIs that AI agents can buy per call with x402. Many of them are paid through Circle Gateway: the agent pays from USDC it deposited in Circle's Gateway Wallet, signs off-chain, and Circle settles the payments in batches, without gas. That makes very small payments possible. But only a client built for Gateway can pay that way. A standard x402 client signs an ordinary USDC transfer, and a Gateway-only seller refuses it. Circle has just released skills that let Claude Code build such sellers, so we looked at who can pay the catalog today.

2,856listings from 125 sellers in Circle's catalog
68%of the listings take only Circle Gateway
30%can be paid by a standard x402 client
5sellers behind all the Gateway-only listings

1. Who can pay what

Every listing in the catalog carries the payment options its seller offers. Sorted by what a buyer needs:

The listing offersListingsSellersWho can pay
Only Circle Gateway1,935 (68%)5Only a Gateway client with a Gateway balance
Gateway and a standard option145 (5%)4Any x402 client
Only standard x402713 (25%)116Any x402 client
No payment option listed63 (2%)14Nobody, as listed

So an agent with a standard x402 client, such as Coinbase's x402 packages or an AgentKit wallet, can pay 858 of the 2,856 listings (30%). An agent with Circle's Gateway client and a Gateway balance can pay the 2,080 Gateway listings, and the standard ones too if its client also has a standard fallback (below).

2. Many listings, few sellers

By seller the picture turns around. 116 of the 125 sellers (93%) offer only standard x402. The 1,935 Gateway-only listings come from just 5 sellers, and one of them lists 1,579 endpoints: 55% of the whole catalog. The other four list 289, 41, 15 and 11.

Almost all of that seller's endpoints cost $0.10 per call. Of all Gateway-only listings, 1,582 cost $0.10, and 1,420 offer the same 8 networks: Arc, Base, Polygon, Ethereum, Avalanche, Arbitrum, Optimism and Unichain. One Gateway balance pays on any of them.

3. Where Gateway shines: nanopayments

The 145 listings that offer both are a different kind of service. 132 of them cost $0.0001 per call, a hundredth of a cent. On a standard on-chain transfer the gas would cost more than the call; batched settlement is what makes that price possible. Their sellers also offer a standard option, so every x402 agent can still buy, and the agents with a Gateway balance pay without gas.

4. What our daily scan sees

x402 Doctor reads this catalog every day and calls each endpoint once, without paying. In the scan of 19 October it reached 1,714 of the 1,916 distinct Gateway-only endpoints. 290 of them got go. The other 1,422 got caution, but for a reason that turned out to be ours: their 402 gives the resource as a path (/apis/v2/…) instead of the full URL, as Circle's middleware does, and until that day our scan counted every path as a mismatch. It now resolves the path, sees that it matches, and only warns; registries and some clients do expect the full URL.

All 141 endpoints with both options that the scan reached could be paid. Of the standard-only endpoints it reached, 508 of 599 got go.

From the scan of 20 October on, the pre-payment check gives Gateway-only endpoints caution for what they are (gateway_only): a standard client can't pay them. An agent that pays with Circle's client gets go (below).

For agents: pay both ways, and check first

Circle's client package can sit inside a standard x402 client. Registered with a fallback, it pays Gateway offers from the Gateway balance and standard offers with an ordinary USDC transfer. From Circle's own documentation of @circle-fin/x402-batching:

import { x402Client } from "@x402/core/client";
import { registerBatchScheme } from "@circle-fin/x402-batching/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";

const client = new x402Client();
// Handles both batch (Gateway) and standard EVM payments:
registerBatchScheme(client, {
  signer: account,
  fallbackScheme: new ExactEvmScheme(account),
});

Gateway payments still need USDC deposited in the Gateway Wallet first. Before paying an endpoint it hasn't used, an agent can ask x402 Doctor's pre-payment check: GET https://x402-doctor.fizzl.eu/api/v1/preflight?url=… ($0.001). A Gateway-only endpoint gets caution (gateway_only), because a standard client can't pay it. An agent that pays with Circle's client adds &client=gateway and gets a plain go, with the Gateway option recommended.

For sellers: offer a standard option next to Gateway

Circle's seller middleware (createGatewayMiddleware) offers Gateway options only. That is the fastest start. To reach every x402 agent as well, list a plain exact option for the same route next to the Gateway ones, as the four sellers in section 3 do. With x402's standard resource server you can run Circle's facilitator client next to your usual one; Circle's README shows the first half:

import { x402ResourceServer } from '@x402/core/server';
import { BatchFacilitatorClient } from '@circle-fin/x402-batching/server';

const server = new x402ResourceServer([
  new BatchFacilitatorClient(),
  // your usual facilitator for the standard "exact" option
]);

Then check what your 402 offers: the free web check knows Gateway on every network Circle serves, testnets included, and says who can pay you. More on selling through Gateway: x402-doctor.fizzl.eu/sellers.

How we measure

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