Skip to main content

​
Introduction to HTTPayer

HTTPayer is a cross-chain stablecoin payment framework that enables payment-gated APIs using the HTTP 402 Payment Required standard and the x402 Protocol. It allows developers to monetize APIs while abstracting away blockchain complexity for clients.

​
What is HTTPayer?

HTTPayer acts as a payment router and execution layer for APIs that implement the x402 Protocol. It provides:
  • Cross-chain and multi-chain payments
    Pay on one network and access APIs on another.
  • Optional Web3 wallet usage
    Clients can access payment-gated APIs using a traditional account system without managing wallets.
  • Privacy-preserving access
    Requests are relayed through HTTPayer, so the target API does not directly know who made the payment or request.
  • Automated payment verification
    Secure validation of EIP-3009 authorizations and on-chain settlement.
  • Request proxying
    Seamless forwarding to destination endpoints and response delivery.
  • Refund safety guarantees
    Payments are only finalized when the target API actually charges.

​
Supported Protocol Version

HTTPayer currently supports:
  • x402 Protocol v1

​
Supported Networks

HTTPayer supports stablecoin payments on the following networks:

​
EVM

  • base
  • base-sepolia
  • skale-base
  • skale-base-sepolia

​
Solana

  • solana
  • solana-devnet

​
Key Features

​
402 Payment Required Support

HTTPayer implements the HTTP 402 standard, allowing APIs to require payment before serving responses.

​
Cross-Chain & Multi-Chain Payments

Clients may pay on one network while accessing APIs deployed on another, with HTTPayer handling settlement behind the scenes.

​
Flexible Client Models

  • Wallet-based access via x402 payment headers
  • Account-based access via API keys and credits

​
Secure & Gasless Payments

Uses EIP-3009 (transferWithAuthorization) to enable secure, gasless USDC payments.

​
Endpoint Model Overview

HTTPayer exposes two primary access patterns:

​
/relay — x402-native access

  • Directly implements the x402 Protocol
  • Uses payment headers for authorization
  • Does not require an API key
  • Supports cross-chain access
  • Issues refunds if payment is not finalized

​
/proxy — account-based abstraction

  • Uses API keys for authentication
  • Abstracts on-chain payments from the client
  • Credits are only deducted if HTTPayer is charged
  • Ideal for Web2 and server-side integrations

​
Use Cases

  • AI / LLM APIs — Monetize inference and agent calls
  • Data APIs — Charge per request or per query
  • Compute Services — Micropayments for compute-heavy workloads
  • Web3 Services — Paid blockchain interactions without wallet friction

​
Next Steps

Quickstart

Get started with your first API call

API Reference

Browse the complete API documentation