Ultravioleta DAO is a hosted facilitator service that supports x402 v1 and v2 payment processing across 33+ networks. By using its endpoints, you can offload payment verification and settlement on SKALE Base.
Prerequisites
Node.js 18+ or Python 3.10+
A wallet with USDC.e on SKALE Base
Basic understanding of x402 protocol
Configuration Environment Variables Create a .env file with Ultravioleta DAO configuration:
# Receiver address for the x402 payment RECEIVING_ADDRESS = 0xYourWalletAddress # please don't share your private key with anyone PRIVATE_KEY = 0xyour_pk
Integration with Ultravioleta DAO Server Setup
Client Setup
Install dependencies: npm install hono @hono/node-server uvd-x402-sdk dotenv
import { Hono } from 'hono' ; import { serve } from '@hono/node-server' ; import { createHonoMiddleware } from 'uvd-x402-sdk' ; import 'dotenv/config' ; const app = new Hono (); const receiver = process . env . RECEIVING_ADDRESS as string ; // Create x402 payment middleware for SKALE Base const paywall = createHonoMiddleware ({ accepts: [{ network: 'skale-base' , asset: '0x85889c8c714505E0c94b30fcfcF64fE3Ac8FCb20' , amount: '1000000' , // $1.00 USDC.e (6 decimals) payTo: receiver , extra: { name: 'Bridged USDC (SKALE Bridge)' , version: '2' , }, }], }); // Free endpoint — no payment required app . get ( '/api/free' , ( c ) => { return c . json ({ type: 'free' , message: 'This endpoint is free!' , timestamp: new Date (). toISOString (), }); }); // Protected endpoint — middleware handles 402, verify, and settle automatically app . get ( '/api/premium' , paywall , ( c ) => { return c . json ({ type: 'premium' , message: 'Payment verified and settled on SKALE Base!' , timestamp: new Date (). toISOString (), }); }); serve ({ fetch: app . fetch , port: 3000 }); console . log ( 'Server running on http://localhost:3000' );
Install dependencies: npm install uvd-x402-sdk ethers dotenv
import { X402Client } from 'uvd-x402-sdk' ; import 'dotenv/config' ; const client = new X402Client ({ defaultChain: 'skale-base' }); // Connect with private key (works in Node.js, no browser wallet needed) await client . connectWithPrivateKey ( process . env . PRIVATE_KEY as string ); const result = await client . createPayment ({ recipient: process . env . RECEIVING_ADDRESS as string , amount: '1.00' , }); const response = await fetch ( 'http://localhost:3000/api/premium' , { headers: { 'X-PAYMENT' : result . paymentHeader }, }); if ( response . ok ) { const data = await response . json (); console . log ( 'Response data:' , data ); } else { console . error ( `Error: ${ response . statusText } ` ); }
Troubleshooting Connection Issues If you cannot connect to the Ultravioleta DAO facilitator:
Verify the facilitator URL is correct: https://facilitator.ultravioletadao.xyz
Check network connectivity
Review firewall settings
Payment Failures Common causes and solutions:
Issue Solution ”Invalid signature” on SKALE Verify EIP-712 domain name is "Bridged USDC (SKALE Bridge)" with version "2" Transaction reverts SKALE uses legacy (type 0) transactions — do not set maxFeePerGas Balance shows 0 Check USDC.e at 0x85889c8c714505E0c94b30fcfcF64fE3Ac8FCb20, not native CREDIT Network mismatch Use network name skale-base (Chain ID 1187947933) Expired authorization Increase maxTimeoutSeconds
Next Steps
SKALE Supported Facilitators See all available facilitators for SKALE
Run Your Own Deploy your own facilitator infrastructure
Accept Payments Protect endpoints with payment middleware
Make Payments Build clients that handle x402 payments
Resources This entity — Ultravioleta DAO — is deployed and actively supporting SKALE. These are 3rd party services that may have their own terms and conditions and privacy policies. Use these services at your own risk. AI and agents is a highly experimental space; the 3rd party software solutions may have bugs or be unaudited. You and your agents and your customers use all 3rd party services chosen at your own risk and per their terms.
