Gasless Micropayments for the Agentic Economy
Enable AI agents to transact autonomously without gas fees. Built on x402 protocol with EIP-3009 meta-transactions.
Avalanche C-Chain
Base
HyperEVM
Polygon
Solana
Optimism
Ethereum
Arbitrum
Unichain
Monad
NEAR
Stellar
Fogo
Algorand
BNB Chain
Sui
SKALE Base
Scroll
Avalanche Fuji
Base Sepolia
Polygon Amoy
Optimism Sepolia
Ethereum Sepolia
Arbitrum Sepolia
Unichain Sepolia
HyperEVM Testnet
NEAR Testnet
Stellar Testnet
Fogo Testnet
Algorand Testnet
Solana Devnet
Sui Testnet
SKALE Base Sepolia
Gasless Transactions
Agents never need AVAX or ETH for gas. The facilitator executes transferWithAuthorization via EIP-3009.
Trustless by Design
EIP-712 signature verification ensures cryptographically valid payments before on-chain execution.
Instant Settlement
Complete payment verification and on-chain settlement in ~2-3 seconds end-to-end.
On-Chain Reputation
ERC-8004 Trustless Agents with identity, reputation, and validation registries across 16 networks.
Integrate in Minutes
Our SDKs handle payload construction, signature verification, and multichain settlement automatically. By default, all requests use our facilitator - no configuration needed.
npm install uvd-x402-sdk// Client: Create payment with any stablecoin
import { createPayment } from "uvd-x402-sdk";
const payment = await createPayment(wallet, {
recipient: "0xYourWallet",
amount: "10.00",
tokenType: "eurc" // usdc | eurc | ausd | pyusd
});
// Server: Verify payment
import { verifyPayment } from "uvd-x402-sdk";
const result = await verifyPayment(
request.headers["X-PAYMENT"],
{ maxPrice: "10.00", recipient: "0xYourWallet" }
);No payload construction needed
19 mainnets supported
Default facilitator configured
What is x402?
x402 is a protocol for stateless, per-request payments over HTTP. Clients attach a signed payment payload to each request. The facilitator verifies it, executes the on-chain transfer, and grants access to protected resources—all without accounts, wallets, or user registration.
Trustless Agent Reputation
On-chain identity, reputation, and validation for AI agents. Rate service quality, verify agent identities, and build trust across the agentic economy — all verifiable on-chain through ERC-8004 registries.
Identity Registry
Register agents as on-chain NFTs via POST /register. The facilitator pays gas — optionally mint to a user address. Read identity, metadata, and total supply via the API.
Reputation Registry
Submit, revoke, and query reputation feedback with proof-of-payment. Tags enable categorized ratings like uptime, quality, and response time.
Validation Registry
Third-party validators can attest to agent capabilities. Validation results are stored on-chain for transparent trust verification.
Deployed on 18 Networks
Ethereum
Base
Polygon
Arbitrum
Optimism
Celo
BNB Chain
Monad
+ 8 testnets. EVM mainnets use CREATE2 deterministic addresses. Solana uses the QuantuLabs Agent Registry program.
Trustless Escrow & Refunds
On-chain escrow with authorize/capture/release/refund flows. Funds are held in smart contracts until conditions are met, enabling trustless refunds for HTTP 402 payments across 9 networks.
Escrow Settlement
Payments are authorized and held in on-chain escrow contracts. Funds remain locked until the seller captures or the buyer requests a refund.
Trustless Refunds
Buyers can request refunds within a configurable time window. No intermediary needed — the smart contract enforces the refund policy on-chain.
Authorize & Capture
Two-phase settlement: authorize first, capture later. Sellers can charge partial or full amounts, and release remaining funds back to the buyer.
Escrow Deployed on 9 Networks
Ethereum
Base
Polygon
Arbitrum
Celo
Monad
Avalanche
+ 2 testnets (Base Sepolia, Ethereum Sepolia). Each network has its own deployed contract set.
Usage-Based Payments
Authorize a maximum payment upfront, pay only for what you use. Built on Uniswap Permit2 for gasless variable-amount settlements across all EVM networks.
Pay As You Go
Client signs a max amount via Permit2. Server charges only the actual usage. Zero-cost if nothing is consumed.
Permit2 Powered
Uses Uniswap's Permit2 contract for gasless ERC-20 approvals. One signature authorizes the max; settlement can be any amount up to that limit.
Built for AI Agents
Ideal for LLM token billing, bandwidth metering, and any usage-based API. Agents pre-authorize, consume resources, and pay the exact cost.
API Endpoints
Status & Info
x402 Protocol
x402r Escrow (Refund Support)
Add {"refund": {"window": 86400}} to extensions for trustless refund support via DepositRelay proxies.
x402r PaymentOperator (Advanced Escrow)
Advanced escrow with authorize/charge/release/refund flows. Funds held in TokenStore until capture.
Upto Scheme (Permit2 Variable Settlement)
Client authorizes max amount via Permit2 signature. Server settles for actual usage (<= max). If usage is $0, no on-chain transaction is submitted.
ERC-8004 Agent Registration
recipient field to mint the NFT and transfer it to a user address
Gasless registration: The facilitator wallet pays all gas fees. Without recipient, the NFT stays with the facilitator. With recipient, the NFT is minted then transferred via ERC-721 safeTransferFrom (2 transactions, both paid by facilitator). Note: agentWallet is cleared on transfer and must be re-set by the new owner.
ERC-8004 Agent Identity
ERC-8004 Reputation Feedback
16 networks: ethereum, base, polygon, arbitrum, optimism, celo, bsc, monad, avalanche + testnets. All mainnets use CREATE2 deterministic addresses.
Compliance
Discovery (Bazaar)
Interactive API Documentation
Explore all endpoints interactively with Swagger UI. Try requests directly from your browser, view schemas, and download the OpenAPI spec.