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

# Welcome to h402

<Card title="This project is Open Source" icon="github" href="https://github.com/bit-gpt/h402" arrow="true">
  Explore the complete collection of h402 solana RPC integration examples in our repository.
</Card>

## h402 is an open, HTTP-compatible protocol that enables stateless machine-to-machine payments

Thirty-five years after Tim Berners-Lee set aside the 402 Payment Required response code, the web still lacks a native, programmable unit of value. h402 aims to close this gap by providing a thin, header-based payment primitive that integrates directly into any HTTP interaction.

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## Overview

h402 repurposes the unused `402 Payment Required` HTTP status code to introduce a simple and interoperable payment negotiation mechanism between clients and services. It enables:

* Machine-to-machine payments using native blockchain assets
* Service monetization without centralized payment gateways
* Stateless, cryptographically verifiable interactions
* Cross-chain and token-agnostic design

Any HTTP-capable agent or service can adopt h402 to define access requirements, request payment and verify them using our protocol.

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## Key Capabilities

* **Chain-Plural**: The protocol treats multiple settlement networks (EVM chains, Solana and soon many others) as first-class options.
* **HTTP-Native**: Seamless integration with existing web infrastructure through standard headers and status codes.
* **Extensible**: Support for new payment schemes, compliance requirements, and future network integrations.
* **Production-Ready**: Built for real-world deployment with comprehensive tooling and facilitator support.

<Note>
  While clients operate in a completely stateless manner, the Facilitator
  maintains state for transaction verification and settlement.
</Note>

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## Use Cases

h402 enables a new market layer for code, including:

* **Instant-Settlement Service Calls**: LLM inference, real-time market data, per-frame video analytics
* **Compute & Storage Markets**: GPU spot markets, elastic storage, DePIN rewards
* **Context & Content on Demand**: Per-document legal archives, premium content, scientific datasets
* **Device-to-Device Commerce**: EV charging, factory automation, logistics coordination

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## Next Steps

This section of the documentation provides everything you need to understand, implement and integrate the h402 protocol:

* **[Core Concepts](/h402/core)** – Protocol architecture and payment lifecycle
* **[Quickstart Guide](/h402/quickstart)** – Implementation guide with SDK examples
* **[Integration Examples](/h402/examples)** – Real-world patterns and use cases