VERIFY │ SETTLE │ NO CHAIN INFRASTRUCTURE
An x402 facilitator, at the edge.
A facilitator is the piece between HTTP and settlement: it checks the payment a client presents, moves the money, and tells your server whether to serve the response. Yours never opens a socket to a chain.
New to the protocol? Start with what x402 is.
Three jobs, one service.
The client presents a signed authorization. The facilitator checks that it is well formed, for the right resource, and worth what the server asked.
The transfer is submitted on-chain on the server's behalf, so the server needs no wallet, no node and no gas.
The server gets a verdict it can act on, and the client gets its response — one round trip, from the caller's point of view.
01
Ask it what it supports.
Every x402 facilitator answers /supported. Ours is public, and it takes no key to read.
curl -sS https://vertically-winning-weevil.edgecompute.app/supported | jq .WHAT IT ANSWERS
{
"kinds": [
{ "x402Version": 2, "scheme": "exact", "network": "eip155:8453" },
{ "x402Version": 2, "scheme": "exact", "network": "eip155:84532" },
{ "x402Version": 2, "scheme": "upto", "network": "eip155:8453",
"extra": { "facilitatorAddress": "0xFBe0d6e9c473Ffa2335758E3a3bB934c92396C56" } },
{ "x402Version": 2, "scheme": "upto", "network": "eip155:84532",
"extra": { "facilitatorAddress": "0xFBe0d6e9c473Ffa2335758E3a3bB934c92396C56" } }
],
"signers": { "eip155:*": ["0xFBe0d6e9c473Ffa2335758E3a3bB934c92396C56"] }
}02
The buyer signs a ceiling, not a price.
SCHEME · EXACT
The buyer signs an EIP-3009 authorization for one exact amount. The price has to be known before the call — fine for a fixed-price endpoint, awkward for anything metered.
SCHEME · UPTO
The buyer signs a Permit2 authorization for a maximum, and the facilitator settles what the call actually cost. A per-call ceiling stops being a guess, and metered endpoints work without a quote round trip.
It needs one Permit2 approval, once, per buyer: the allowance the scheme settles against, with the facilitator address above as its spender. Like any Permit2 allowance it can be lowered or revoked whenever you want, and it does not touch the rest of the wallet.
Want to point your server at it?
We onboard facilitator users by hand for now. Leave an address and we will get in touch — tell us the endpoint you want to charge for and we will tell you what it takes.