> ## Documentation Index
> Fetch the complete documentation index at: https://docs.httpayer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Get started with HTTPayer Proxy API

# 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.

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## 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.

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## Supported Protocol Version

HTTPayer currently supports:

* **x402 Protocol v1**

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## Supported Networks

HTTPayer supports stablecoin payments on the following networks:

### EVM

* `base`
* `base-sepolia`
* `skale-base`
* `skale-base-sepolia`

### Solana

* `solana`
* `solana-devnet`

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## 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.

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## 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

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## 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

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## Next Steps

<Card title="Quickstart" icon="bolt" href="/api/quickstart">
  Get started with your first API call
</Card>

<Card title="API Reference" icon="code" href="/api/overview">
  Browse the complete API documentation
</Card>