# 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

- https://x402docs.com/what-is-x402 - Definition, roles, fit, and caveats.
- https://x402docs.com/http-402-flow - v2 HTTP flow and payment headers.
- https://x402docs.com/server-integration - Seller route and middleware checklist.
- https://x402docs.com/client-agent-guide - Buyer, wallet, and agent policy guide.
- https://x402docs.com/facilitators - Verify/settle role and facilitator trust model.
- https://x402docs.com/networks-and-assets - CAIP-2 identifiers, assets, and network tradeoffs.
- https://x402docs.com/payment-schemes - exact, upto, and batch-settlement comparison.
- https://x402docs.com/security-and-reliability - Production security and reliability checklist.
- https://x402docs.com/v1-to-v2-migration - Legacy x402 to v2 migration map.
- https://x402docs.com/mcp-and-agent-commerce - MCP and agent commerce patterns.
- https://x402docs.com/x402-vs-subscriptions - x402 compared with subscriptions, API keys, and prepaid access.
- https://x402docs.com/x402-header-format - v2 payment-header format, legacy header migration, and debugging.
- https://x402docs.com/source-map - Primary source registry.

## Free Tools

- https://x402docs.com/tools/ - Index of free browser-only x402 tools.
- https://x402docs.com/tools/402-builder - Generate a v2 PAYMENT-REQUIRED response, Base64 header, JSON, and curl retry shape.
- https://x402docs.com/tools/pricing-calculator - Compare x402 per-call API pricing with subscription or API-key alternatives.
- https://x402docs.com/tools/header-decoder - Decode x402 Base64 payment headers locally and inspect version/field hints.

## 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: https://x402docs.com/llms-full.txt