Are cheaper x402 APIs worse?
Not necessarily. Price is rarely what decides which API agents use. Whether the endpoint answers, whether its live price matches its listing, and whether buyers return matter more.
A reseller outsold the original at a higher price
On October 29, 2026, Coinbase's Bazaar listed Exa's own search endpoint (api.exa.ai/search) at 0.007 USDC with 96 unique payers and 8,945 calls in the previous 30 days. A reseller of the same search (stableenrich.dev/api/exa/search) was listed at 0.01 USDC with 165 payers and 30,768 calls. The dearer route had more buyers and about three times the calls.
The difference was not the price. Agents choose from what the index returns for their query, and Bazaar search is text matching on the listing's description. A description that names the task in plain words, and a listing that appears where agents search, matter more than a few tenths of a cent.
What matters more than price
Is the endpoint live now? An unpaid request to a working endpoint returns HTTP 402 with a price, a network and a payTo address. A listing whose endpoint times out or returns a server error costs the buyer a failed call.
Does the live price match the listing? The index records a price at indexing time; the 402 challenge carries the current one. A gap between them means the listing is stale or the seller has repriced.
Do the same buyers come back? The l30DaysTotalCalls and l30DaysUniquePayers fields on each listing show whether a resource is used repeatedly or tried once.
The real cost of cheap
A cheap API that does not answer costs more than a dearer one that does. The buyer still spends the request, the retries and the time, and gets nothing back. Reliability and a clear scope, not the lowest price, decide what gets called again.
Take the next step
The pages below go deeper on this question.
Sources and observed evidence
Continue reading
Publish an x402 API profile with a readiness report and badge
Prepare your x402 API for agent discovery: validate free, inspect readiness evidence, then publish an Ontario service profile for 0.50 USDC only when you need it.
MCP Registry, Smithery or Bazaar: build the agent purchase path
Separate MCP installation from paid API discovery. Give agents a callable tool, free preflight, explicit payment requirements and evidence of fulfilled output.
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.
How big is the x402 market?
Coinbase's Bazaar index lists tens of thousands of paid endpoints, but most show one or two payers in 30 days, and repeat demand sits in a few categories.
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.