​
x402 Protocol Overview

x402 transforms any HTTP endpoint into a paid service using blockchain micropayments. Originally designed as an extension to HTTP status codes, X402 enables seamless monetization of APIs, content, and digital services.

​
Core Components

402 Status Code

HTTP Payment Required Standard HTTP status indicating payment is needed to access the resource.

Payment Headers

X-402-Payment Headers Cryptographic proof of payment embedded in HTTP requests.

Facilitators

Payment Processors Server-side components that handle payment verification and enforcement.

Clients

Payment Makers Client libraries that automatically handle payment creation and retry logic.

​
How x402 Works

The protocol adds payment capabilities to standard HTTP by introducing payment headers and the 402 Payment Required status code:

​
Facilitators and Clients

The x402 ecosystem consists of two main types of components that work together to enable seamless micropayments: Facilitators are server-side services that:
  • Verify payment proofs from blockchain transactions
  • Enforce payment requirements for protected resources
  • Handle payment settlement and confirmation
  • Provide APIs for payment status checking
Clients are libraries and tools that:
  • Automatically detect 402 Payment Required responses
  • Create and submit blockchain payments
  • Retry requests with payment headers
  • Manage wallet connections and user interactions
This separation allows developers to focus on their core business logic while the x402 infrastructure handles all payment complexity.

​
Learn More

Facilitators

Learn how to set up and configure payment processors

Client Integration

Integrate x402 payments into your applications