The Complete Guide to x402 Protocol & AI Agent Payments
Everything you need to know about x402 — the HTTP 402 protocol enabling AI agents to pay for APIs with USDC micropayments. Tutorials, comparisons, and deep dives.
Latest Articles
x402 in 2026: Stripe Support, Cloudflare Foundation, and What Changed
The x402 ecosystem exploded in 2026 — Stripe integration, Cloudflare co-founding the x402 Foundation, Solana hitting 35M+ transactions, and Google AP2. Here's everything that changed.
x402 vs Stripe vs Google AP2: AI Agent Payment Protocols Compared
Compare x402 vs Stripe vs Google AP2 for AI agent payments. Fee breakdowns, developer experience, and which protocol fits your use case.
How to Build a Pay-Per-Query API with x402 and Python (FastAPI)
Step-by-step tutorial: build a pay-per-query AI API using x402 and FastAPI. Accept USDC micropayments on Base for every API call.
Building an x402-Powered MCP Server: Let AI Agents Pay for Your Tools
Learn how to build an MCP server that accepts x402 payments, letting AI agents like Claude autonomously pay for your tools and APIs.
What is x402 Protocol? Complete Beginner Guide
Learn what the x402 protocol is, how it enables machine-to-machine payments using HTTP 402, and why it matters for AI agent commerce.
How AI Agents Pay for Services with x402
Discover how autonomous AI agents use x402 to pay for APIs, data, and services without human intervention.
x402 Payment Flow Explained Step by Step
Visual walkthrough of the complete x402 payment flow from HTTP 402 response to USDC settlement. Every step explained.
x402 vs Traditional API Billing: Cost Comparison
Compare x402 micropayments against subscription models, API keys, and usage-based billing. See the real cost breakdown.
Building Your First x402 Service with Node.js
Build a complete x402-enabled API from scratch using Node.js, Express, and the x402 SDK. Full code walkthrough included.
How to Build a Pay-Per-Query API with x402 and Python (FastAPI)
Step-by-step tutorial: build a pay-per-query AI API with x402, FastAPI, and Claude. USDC micropayments on Base network with real code examples.
UltravioletaDAO vs CDP Facilitator: Which to Choose
Compare the two main x402 facilitators — UltravioletaDAO and Coinbase CDP. Features, fees, and which is right for you.
How to Accept x402 Payments in Your API
Step-by-step tutorial on adding x402 payment support to your existing API endpoints with code examples.
x402 Pricing Strategies: Maximizing Revenue
Learn how to price your x402 API endpoints for maximum revenue. Covers per-request pricing, tiered models, and market positioning.
Setting Up x402 on Base, Ethereum, and Solana
Guide to deploying x402 services across different blockchains. Compare gas costs, settlement speed, and ecosystem support.
USDC Micropayments with x402: Technical Deep Dive
Technical breakdown of how x402 processes USDC micropayments, including EIP-3009 authorization, facilitator verification, and settlement.
x402 Bazaar: How Bots Discover Your API
Learn how x402 Bazaar works as a discovery layer for AI agents to find and consume your API services automatically.
x402scan Marketplace: Getting Listed and Found
How to get your x402 service listed on x402scan, optimize your listing, and attract more AI agent customers.
Security Best Practices for x402 Services
Protect your x402 service from replay attacks, overpayment exploits, and facilitator verification bypasses. Essential security guide.
Comparing x402 Facilitators: Features and Fees
Detailed comparison of all x402 facilitators including fee structures, supported chains, verification speed, and reliability.
The Future of AI Agent Commerce with x402
Explore where x402 and AI agent payments are heading. Market predictions, emerging use cases, and the road to autonomous commerce.
Building an x402-Powered MCP Server: Let AI Agents Pay for Your Tools
Step-by-step tutorial on building an MCP server that accepts x402 USDC micropayments. Includes code examples and a live npm package reference.
Try an x402-Powered Service
AskClaude.shop is a live x402 service — AI agents pay per query with USDC micropayments.
Visit AskClaude.shop