Coinbase Unveils x402 Protocol to Enable Autonomous Payments for AI Agents

Coinbase has introduced x402, a groundbreaking payments protocol designed to empower AI agents and apps to make real-time, autonomous transactions over the internet using stablecoins. Announced on May 6, the protocol could mark a major leap forward in automating digital commerce and transforming artificial intelligence into economically independent actors.

Built on top of the standard HTTP (Hypertext Transfer Protocol), x402 enables stablecoin payments directly through internet communication protocols, eliminating the need for traditional payment rails such as credit cards or bank transfers.

“We’re laying the groundwork for an economy run not just by people, but by software — autonomous, intelligent, and always on,” said Erik Reppel, head of engineering at Coinbase Developer Platform and co-author of the x402 white paper.

Reviving HTTP 402 for a Web-Native Payment Layer

At the core of the innovation is the resurrection of HTTP status code 402 – ‘Payment Required’, a long-unused placeholder in the original web standards. Coinbase is reimagining this feature to natively integrate payments into web interactions, making economic exchange as frictionless as sending data.

The company says today’s payment infrastructure is outdated, expensive, and overly manual—“built for a pre-internet world.” In contrast, x402 provides a lightweight, developer-friendly solution that enables both humans and AI agents to send and receive payments without centralized platforms or account-level management.

x402 payment flow. Source: Coinbase

AI Agents as Economic Actors

One of the most transformative aspects of x402 is its potential impact on agentic AI. By enabling AI agents to transact in real time, the protocol frees them from relying on human-managed accounts, pre-paid credits, or static API keys.

This autonomy allows AI systems to:

• Access and pay for hardware resources on demand.

• Purchase data streams via micropayments.

• Interact economically with other AI agents or services to achieve tasks independently.

Essentially, AI agents become economically autonomous actors, capable of discovering, paying for, and utilizing digital and physical resources without manual oversight.

A Broader Ecosystem of Partners

Coinbase is rolling out x402 in collaboration with several major players in tech and crypto, including:

• Amazon Web Services (AWS)

• Circle, issuer of the USDC stablecoin

• Anthropic, an AI research company

• Near Protocol, a proof-of-stake blockchain optimized for AI applications

Gagan Mac, VP of Product Management at Circle, said x402 “elegantly simplifies real-time monetization,” enabling new models like per-use billing and pay-per-request APIs.

Opportunities for Developers and Creators

x402 opens up a wide range of use cases for developers and digital creators. API providers can implement dynamic pricing, metered billing, or one-click software unlocks. Content creators, on the other hand, can monetize their work without relying on subscriptions or credit card fees, enabling seamless microtransactions directly embedded in web interactions.

By embedding stablecoin payments into the internet’s core architecture, Coinbase's x402 aims to build a faster, more flexible, and AI-native economic layer for the digital world.