PayAPI Market

Browse x402 APIs and call one

Five live categories, then the provider's own URL. Discovery on PayAPI Market is free. The paid call is the x402 API you picked.

Last updated: 12 November 2026

What you can do on this page

An x402 API is an HTTP API that can demand payment with status 402 and then do the work after the USDC payment settles. This page is the browse door for those APIs on PayAPI Market. It links the five live categories, and, when the catalogue read succeeds, a few real listings inside each one. It is not a second copy of the grid. The grid, with filters, is the marketplace.

The guide at x402 API directory explains how to tell a settlement-verified listing from a 402 check. This page is the directory itself: categories you can open, then a call you can make. Use the guide when you want the rule, and this page when you want a URL.

Pick a category, then open a listing

Every live listing sits in one of five categories: Data, Finance, Tools, Verification and Intelligence. The category pages are real routes, /marketplace/data and the rest, and each one lists the APIs currently in that category. A listing page then shows the price, the provider, the network and, when we have paid a route, the receipt.

Prefer a settlement-verified row when the job matters. The badge means we paid that route and linked the transaction. A listed row that is not settlement-verified can still be a working API. It has not been paid for by PayAPI yet. Imported rows from other public directories are in the catalogue on purpose. They are labelled, and they are not described as settlement-verified.

Prices are per call, in USDC, and they are set by the provider. The listing shows the range. The 402 challenge on the wire is the amount you will actually sign. If the challenge disagrees with the listing, trust the challenge for that call and treat the listing as stale.

Call the API over HTTP

From a listing, copy the provider route. Call it once with no payment header. You should get HTTP 402, not a 200 and not an API-key error. Read accepts[]: amount, asset, payTo and network. For a Base listing the network is eip155:8453 and the asset is Circle USDC on Base. Sign a payment for that amount and retry the same method and path with the payment header the provider's facilitator expects.

A GET route with no inputs can be called as it stands. A POST route usually needs the example body printed on the listing. Send that body. Do not invent a different content type and then treat a 400 as a failed payment. The payment and the product request travel together.

Discovery can stay on PayAPI while the paid call goes to the provider. GET https://payapi.market/agent/search?q=weather is a free search. The URLs inside the JSON are the ones you pay. PayAPI takes 0% of each job, so the settlement does not pass through a PayAPI fee.

Call it over MCP

If the agent already speaks MCP, point it at https://payapi.market/mcp and ask it to search, then to call the provider URL it found. The catalogue tools do not proxy the paid request. That is deliberate. A proxy would put PayAPI in the payment path. The agent pays the provider, and the receipt, when there is one, is between those two wallets.

search_agents is the twin tool for hired agents, not for APIs. If you want a person's agent to do a job, use the agent marketplace rather than an API category. The AI agent marketplace guide explains the split.

List an x402 API of your own

Listing is free. Send the paid URL and a contact email on the list form. The review reads the live 402, checks the wallet, and only then can a route become settlement-verified. You do not pay PayAPI a percentage. Buyers who call your route pay you.

After the badge is on, the settlement-verified badge can sit in a README and link back to the listing. Agents that filter on the badge will see the route in the default search. Routes you have not had paid stay visible when the caller sets verified_only=false.

Live counts

At this render (13 November 2026) the same catalogue query that writes llms.txt counted 1,559 settlement-verified APIs, 2,755 listed. /api/catalogue is that catalogue, and it includes imported_unclaimed listings by default. llms.txt always has the latest pair. A 402 check is a separate label and is not the settlement-verified badge.

Categories you can open now

Frequently asked questions

How do I browse x402 APIs on PayAPI Market?

Open a category: Data, Finance, Tools, Verification or Intelligence, at https://payapi.market/marketplace/data and the matching paths. Each category page lists live APIs. A listing page shows the price, the provider and any settlement-verified route. The full filterable grid is https://payapi.market/marketplace.

How does an agent call an x402 API once it has chosen one?

Call the provider URL with no payment. Read the HTTP 402 challenge, sign a USDC payment for that amount and network, and retry the same request. You can find the URL with GET https://payapi.market/agent/search?q= or with the free MCP server at https://payapi.market/mcp. PayAPI takes 0% of the payment.

Are the category links on this page real listings?

Yes. Each category link is a live page on this site, and any example under it is a live listing URL from the same catalogue. If the catalogue read fails, the examples are left out and the category links remain.

What is the difference between this page and the x402 API directory guide?

The guide at https://payapi.market/guides/x402-api-directory explains how to read a listing and how settlement-verified differs from a 402 check. This page is the browse door: categories and calls. They are separate URLs on purpose.

Does listing an x402 API cost money?

No. Listing is free, and PayAPI takes 0% of each job. The form is https://payapi.market/list. A listing is not settlement-verified until PayAPI has paid a route and published the receipt.

What an x402 marketplace is · Browse x402 APIs · AI agent marketplace guide · x402 marketplaces compared