How big is the x402 market?
Smaller than the headline numbers suggest. The index is large, but a count of listed endpoints says little about how many agents come back to pay.
What the index counts
Coinbase's public discovery API reported 96,113 indexed resources on October 29, 2026, and Coinbase's seller documentation describes the Bazaar as listing more than 23,000. A resource is indexed after its first payment settles through the CDP facilitator, so each entry proves at least one payment, not a customer.
Each listing carries l30DaysUniquePayers and l30DaysTotalCalls: the facilitator's count of distinct paying wallets and of calls in the last 30 days. Those two numbers are what separate usage from presence.
Most listings have one or two payers
When Ontario pulled the full index on October 17, 2026 (46,420 resources at the time), 74% of resources had one or two unique payers in the previous 30 days. The first paid call that triggers indexing is usually the seller's own, so a count of one or two mostly records sellers paying themselves to get listed. About 20,000 of those routes sat on a single host.
The index has grown since, and Ontario has not repeated the full pull, so the share may have moved. The pattern it describes, a long tail of listings with no outside buyer, is visible in the per-listing counters on any page of the index.
Where repeat demand is
Repeat demand, where calls are many times the number of payers, concentrated in a few categories in that pull: LLM chat and inference, web search and page reading, and on-chain data. Two web-search listings read on October 29, 2026 show the shape: one with 96 payers and 8,945 calls in 30 days, another with 165 payers and 30,768 calls.
Calls per payer is the more useful measure. A resource with 100 payers and 100 calls was tried once by each; one with 165 payers and 30,768 calls is being used. For anyone building for agents, that ratio separates real usage from listing noise.
Take the next step
The pages below go deeper on this question.
Sources and observed evidence
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Can x402 payments be refunded?
An x402 payment is a USDC transfer that is final once it settles, so a refund is a voluntary new transfer and the real protection is a seller that settles after the result exists.
Are cheaper x402 APIs worse?
Not necessarily; price rarely decides which x402 API agents use, as a reseller that charges more than the original search API and gets more calls shows.
Do Claude or ChatGPT pay for MCP tools?
Claude and ChatGPT can call MCP tools, but neither pays for one by itself; a paid MCP tool needs a client wrapper with a funded wallet and a spending limit.
Which networks does x402 support?
x402 is network-agnostic; Coinbase's facilitator settles on Base, Solana, Polygon, Arbitrum, Monad and World, and most paid traffic today is USDC on Base.
How do I get my API discovered by AI agents?
Agents search indexes rather than browse websites, so an API is found through Coinbase's Bazaar, x402scan and directories, and through a description that names the task.
How do I know an x402 endpoint is legit?
Three observable checks show whether an unknown x402 endpoint is live, priced as listed and used by repeat buyers; Ontario's finder runs them for 0.005 USDC.