Ultravioleta DAO | Avalanche Builder Hub

Overview

Ultravioleta DAO, a leading Web3 DAO in Latin America, offers the x402 protocol - a payment infrastructure that enables monetization of AI agents and APIs on Avalanche. The protocol solves a critical challenge: autonomous agents cannot operate without gas money. The x402 facilitator acts as a payment intermediary that verifies transactions, covers gas fees, and settles payments on-chain, allowing agents and services to operate autonomously using USDC payments.

The facilitator is available on both Avalanche C-Chain (Mainnet) and Avalanche Fuji (Testnet), enabling developers to test their integrations before deploying to production.

What is x402?

x402 is an HTTP-based payment protocol built on the standard HTTP 402 "Payment Required" status code. It enables micropayments between services without requiring the paying party to hold native gas tokens. The protocol uses ERC-3009 meta-transactions to allow third-party facilitators to sponsor gas fees while maintaining cryptographic proof of payment authorization.

Key participants:

Merchants: Service providers who monetize their APIs or agent services
Clients: Users or agents who pay for access to services
Facilitators: Infrastructure providers who verify payments and cover gas fees

Features

Gasless Payments: Clients don't need AVAX for gas fees - the facilitator sponsors all transactions
Stablecoin Settlement: Payments settled in USDC for predictable pricing
Cryptographic Security: EIP-712 signatures ensure payment authenticity and prevent replay attacks
Stateless Verification: All payment verification happens on-chain without requiring databases
Fast & Free: Sub-second payment verification with no fees for using the facilitator service
Load Balanced: Auto-scalable infrastructure ensures high availability and reliability
Community Operated: Fully decentralized and community-governed payment infrastructure

Getting Started for Merchants

To monetize your API or agent service using x402:

Set up your service endpoint that you want to monetize
Configure the x402 middleware to protect your endpoint with a price tag
Specify your payment address where USDC payments should be received
Deploy your service - the facilitator handles all payment verification and settlement

Example middleware configuration:

import { Hono } from "hono";
import { paymentMiddleware } from "x402-hono";

const app = new Hono();

// Configure payment middleware
app.use(paymentMiddleware(
  "0xYourWalletAddress",
  {
    "/api/service": {
      price: "$0.01",
      network: "avalanche-c-chain",  // or "avalanche-fuji" for testnet
      config: {
        description: "Access to your API service"
      }
    }
  },
  {
    url: 'https://facilitator.ultravioletadao.xyz'
  }
));

Getting Started for Clients

To pay for x402-protected services:

Initialize the x402 client with your private key and the facilitator URL
Make requests to protected endpoints - payment happens automatically
Receive the response once payment is verified and settled on-chain

Example client usage:

import { X402Client } from "x402-client";

const client = new X402Client({
  privateKey: process.env.CLIENT_PRIVATE_KEY,
  facilitatorUrl: 'https://facilitator.ultravioletadao.xyz',
  network: 'avalanche-c-chain'  // or 'avalanche-fuji' for testnet
});

// Make a paid request
const response = await client.post('https://api.example.com/service', {
  data: { query: 'your request' }
});

Use Cases

AI Agent Monetization

Allow autonomous AI agents to offer services and receive payments without manual intervention. Agents can charge per request, per computation, or per resource consumed.

Pay-Per-Use APIs

Monetize API endpoints with micropayment pricing. Instead of subscription tiers, charge users only for what they consume at granular levels.

Agent-to-Agent Marketplaces

Build trustless marketplaces where autonomous agents buy and sell services from each other, creating self-sustaining AI economies.

Token-Gated Services

Provide access to premium services, data feeds, or computational resources based on per-use payments rather than upfront subscriptions.

Avalanche Integration

The x402 facilitator is optimized for Avalanche deployment on both mainnet and testnet:

Avalanche C-Chain (Mainnet)

Chain ID: 43114
Native Token: AVAX (used by facilitator for gas fees)
Payment Token: USDC
Finality: Sub-second transaction finality for fast payment confirmation
EVM Compatibility: Full support for ERC-3009 meta-transactions

Avalanche Fuji (Testnet)

Chain ID: 43113
Native Token: AVAX (used by facilitator for gas fees)
Payment Token: USDC
Purpose: Test your integration before deploying to mainnet

The facilitator maintains a hot wallet funded with AVAX to sponsor gas fees for all USDC payment settlements. Clients only need USDC in their wallets - no AVAX required.

How It Works

Client Request: Client signs payment authorization using EIP-712 and sends request to merchant
Merchant Verification: Merchant forwards payment proof to facilitator for verification
Facilitator Check: Facilitator verifies signature, checks on-chain balance and nonce
Settlement: Facilitator submits transferWithAuthorization() transaction, paying gas fees
Response: Once settled, merchant receives confirmation and responds to client

All settlements happen on Avalanche using the ERC-3009 standard, ensuring cryptographic security and on-chain auditability.

Documentation

For complete API documentation, integration guides, and example implementations, visit the Ultravioleta DAO facilitator.

About Ultravioleta DAO

Ultravioleta DAO is a leading Web3 DAO in Latin America, focused on building decentralized infrastructure for autonomous agent economies. The organization develops open-source protocols and tools that enable trustless interactions between AI agents, with a focus on payment infrastructure, decentralized governance, and blockchain-based monetization. Learn more at ultravioletadao.xyz.

Conclusion

Ultravioleta DAO's x402 facilitator provides production-ready payment infrastructure for building autonomous agent economies and monetized APIs on Avalanche. By abstracting away gas fee management and providing a simple HTTP protocol for payments, it enables developers to focus on building valuable services while maintaining security through cryptographic signatures and on-chain settlement. Start testing on Fuji testnet today, then deploy to C-Chain mainnet when ready.

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