Guides · Updated 2026-10-17

What is x402? HTTP 402 payments for AI agents, explained

Short answer: x402 is an open standard for paying for things over plain HTTP. When a request arrives without payment, the server replies with status 402 Payment Required; the client (often an AI agent) pays, usually in stablecoins, and retries the request. There's no account signup and no API key to manage.

How does x402 work?

The agent sends a normal HTTP request.
The server answers 402 Payment Required with what it accepts.
The agent pays and retries; the server grants access.

On the server side, x402.org shows payment being added as middleware on a route (for example GET /weather), so each request can require payment.

Why do agents need x402?

The usual way to buy API access is built for people: create an account, add a card, buy credits, store and rotate a key. x402.org's pitch is that an agent can skip all of that and pay per request instead.

What does x402 cost, and which networks does it use?

Protocol fees: none, per x402.org; you pay the payment network's fees.
Networks: EVM-compatible chains and Solana, with stablecoins as the main use case (per x402.org).
Usage: x402.org shows a live 30-day counter on its home page; on 2026-10-17 it read 75.41M transactions and $24.24M volume. These are x402.org's figures, not ours.

Where can you find x402 APIs?

Browse the x402 APIs we track, each with a daily automated check, or search the directory.

See also: agent marketplaces & task boards that pay agents over x402 and on-chain.

Which tools in our directory relate to this, and how do they compare?

Score	Tool	Type	Host
100	x402.botsmith.dev search X Tweet Search ($0.02/call): Search X (Twitter) posts with full advanced-search syntax (from:, since:, until:,	x402 · $0.02	x402.botsmith.dev
100	api.oblique.markets time Use when an agent needs a trusted UTC timestamp or the smallest end-to-end test of its x402 payment client. Re	x402 · $0.01	api.oblique.markets
100	x402tap.com weather Live current weather conditions for any city, sourced from Open-Meteo	x402 · $0.01	x402tap.com
100	api.chit402.com completions Signed spend receipts for agent x402 payments — who paid which call, verifiable by a third party. Treasury des	x402 · $0.002	api.chit402.com
100	api.oblique.markets bazaar-pulse Use when an agent wants one-call situational awareness of the x402 Bazaar before choosing what to buy or sell.	x402 · $0.002	api.oblique.markets
100	randomfactsx402.vercel.app random-fact Returns a single random fact as JSON in exchange for a micropayment.	x402 · $0.01	randomfactsx402.vercel.app

What else do people ask?

What is x402?

x402 is an open, neutral standard for internet-native payments. A server that wants payment answers a request with HTTP 402 Payment Required; the client pays and retries, and access is granted. No account or API key is needed.

Does x402 charge fees?

x402.org says the protocol has zero protocol fees for customers and merchants; you pay only the payment network's fees.

Which blockchains does x402 support?

According to x402.org it is blockchain-agnostic, supports EVM-compatible chains and Solana, uses stablecoins as the primary case, and is extensible to traditional payment methods.

Who governs x402?

x402.org links to a Linux Foundation announcement of the operational launch of the x402 Foundation to standardize internet-native payments for AI agents and applications.

Where can I find x402 APIs?

DartzDabz lists x402 APIs it discovers from public catalogs, with a daily automated check, on the x402 APIs page.

Sources

More guides → · Real agent setups →