Charge for an API in one line
Point any x402 server SDK at https://pay.neuronto.com and advertise a wallet you control. That is the whole
integration: your server never holds a key and never talks to a chain.
new HTTPFacilitatorClient({ url: "https://pay.neuronto.com" })Live right now: eip155:8453. /supported lists every network, scheme and version this
facilitator settles at this moment, and a network that cannot settle disappears from it before it
starts refusing, so a server that reads it never advertises a price it cannot take.
Node, Express
import express from "express";
import { paymentMiddleware, x402ResourceServer } from "@x402/express";
import { ExactEvmScheme } from "@x402/evm/exact/server";
import { HTTPFacilitatorClient } from "@x402/core/server";
const server = new x402ResourceServer(
new HTTPFacilitatorClient({ url: "https://pay.neuronto.com" }),
).register("eip155:8453", new ExactEvmScheme());
const app = express();
app.use(paymentMiddleware({
"GET /premium": {
accepts: { scheme: "exact", price: "$0.001", network: "eip155:8453", payTo: "0xYourWallet" },
description: "One premium answer",
mimeType: "application/json",
},
}, server));
app.get("/premium", (req, res) => res.json({ ok: true }));
app.listen(3000);Python, FastAPI
from fastapi import FastAPI, Request
from x402 import x402ResourceServer
from x402.http import FacilitatorConfig, HTTPFacilitatorClient
from x402.http.middleware.fastapi import payment_middleware
from x402.mechanisms.evm.exact import register_exact_evm_server
server = x402ResourceServer(HTTPFacilitatorClient(FacilitatorConfig(url="https://pay.neuronto.com")))
register_exact_evm_server(server, "eip155:8453")
middleware = payment_middleware({
"GET /premium": {
"accepts": {"scheme": "exact", "payTo": "0xYourWallet", "price": "$0.001",
"network": "eip155:8453"},
"description": "One premium answer",
"mimeType": "application/json",
}
}, server)
app = FastAPI()
@app.middleware("http")
async def x402(request: Request, call_next):
return await middleware(request, call_next)
@app.get("/premium")
def premium():
return {"ok": True}Hono and Next.js versions, and paying clients in Node and Python, are in https://github.com/neuronto/x402-starters.
Test it without spending anything
/echo is a live merchant on this origin: it charges $0.001 and sends it straight
back in the same request, and the gas is ours.
curl -i https://pay.neuronto.com/echoPoint any x402 client at that URL. A replayed payment is answered from the record rather than
charged again, and /echo/status says whether it is serving.
For agents
POST https://pay.neuronto.com/mcp is an MCP server with four tools: facilitator_status, settlement_price,
find_paid_resource and integration_snippet. It needs no key. GET and DELETE on that path
answer 405, never 404, so a client that probes it can tell the difference between a wrong verb
and a server that is not there.
Agent-readable copies of everything: /llms.txt, /openapi.json,
/.well-known/ard.json, /.well-known/api-catalog.
What to read next
- Developer reference: every endpoint, the settlement semantics, the errors.
- Pricing: what a settlement costs and how the figure is computed.
- Status: observed availability, screening, and what is settling right now.