What is a x402 Facilitator?

When an AI agent pays for a service using the x402 protocol, a facilitator handles the payment verification and blockchain settlement. Think of it like a payment processor — you don't interact with the bank directly, the processor handles it.

Different facilitators charge different fees and support different blockchain networks. Most are free, some charge a percentage per transaction, and others use variable pricing.

The x402 protocol uses HTTP status code 402 (Payment Required) to enable machine-to-machine payments. When an AI agent encounters a 402 response, it knows it needs to pay — and the facilitator is the service that makes that payment happen on-chain.

Sellers advertise a price and receiving wallet. Buyers (or agents) sign a payment, the facilitator verifies and settles USDC (or other supported assets), and the API returns the paid response.

Facilitators differ in the chains they support (Base, Ethereum, Solana, Polygon, and more), the tokens they accept (primarily USDC), their fee structures, and whether they're open source or self-hostable.

Use the cost calculator and recommendation tools on this site to compare options against your expected volume and chain.

This directory tracks 20+ facilitators across 10+ chains to help developers and AI agents find the best option for their use case.

x402dir is a public comparison surface — not a facilitator itself. For the protocol homepage and docs, see x402.org.