# x402docs.com

> Source-grounded field guide to x402, the HTTP 402 payment protocol for paid APIs, content, and AI agents.

This site is designed for AI crawlers and human implementers. It prioritizes primary protocol sources and marks provider-specific claims clearly.

## Key Pages

- [What is x402?](https://x402docs.com/what-is-x402/) - Definition, roles, fit, and caveats.
- [HTTP 402 flow](https://x402docs.com/http-402-flow/) - V2 HTTP flow and payment headers.
- [Server integration](https://x402docs.com/server-integration/) - Seller route and middleware checklist.
- [Client and agent guide](https://x402docs.com/client-agent-guide/) - Buyer, wallet, and agent policy.
- [Facilitators](https://x402docs.com/facilitators/) - Verify/settle role and trust model.
- [Networks and assets](https://x402docs.com/networks-and-assets/) - CAIP-2 identifiers, assets, and tradeoffs.
- [Payment schemes](https://x402docs.com/payment-schemes/) - exact, upto, batch-settlement, and auth-capture.
- [Security and reliability](https://x402docs.com/security-and-reliability/) - Production checklist.
- [V1 to V2 migration](https://x402docs.com/v1-to-v2-migration/) - Legacy-to-current migration map.
- [MCP and agent commerce](https://x402docs.com/mcp-and-agent-commerce/) - Agent commerce patterns.
- [x402 versus subscriptions](https://x402docs.com/x402-vs-subscriptions/) - Commercial-model comparison.
- [x402 header format](https://x402docs.com/x402-header-format/) - V2 headers, migration, and debugging.
- [Source map](https://x402docs.com/source-map/) - Primary source registry.

## Free Tools

- [Browser-only tools](https://x402docs.com/tools/) - Tool index.
- [402 response builder](https://x402docs.com/tools/402-builder/) - Generate an exact-payment V2 fixture, Base64 header, JSON, and curl retry shape.
- [Pricing calculator](https://x402docs.com/tools/pricing-calculator/) - Compare per-call and subscription assumptions.
- [Payment header decoder](https://x402docs.com/tools/header-decoder/) - Decode Base64 payment headers locally.

## Primary Source Policy

Protocol claims cite x402 Foundation docs or specs. HTTP status-code claims cite RFC 9110 or MDN. Provider features cite provider docs from Coinbase, Cloudflare, Stripe, Solana, or other named providers.

## Independence

x402docs.com is an independent publication. It is not affiliated with the x402 Foundation, Coinbase, Cloudflare, Stripe, Solana, Anthropic, or linked providers.

Full content summary: [llms-full.txt](https://x402docs.com/llms-full.txt)