What is x402? | Payment Protocol for AI Agents on Solana

An Intro to x402

x402 is an open, internet-native payment protocol built on top of the HTTP 402 status code. Developed by the Coinbase Development Platform team, x402 enables any API or web service to require payment before serving content. It fixes a foundational omission in the web stack, making native payments possible between clients and servers through a universal standard for monetizing digital resources. Learn more about its development at x402.org.

Why Solana for x402?

In a world of agentic payments, the performance of the rails matter. Already traditional payments with stablecoins on the network now exceed $11B in circulation and account for 200M+ transactions every month. Solana's 400ms finality and $0.00025 transaction costs make it an efficient settlement layer for x402 payments. Whether it's an AI agent making thousands of API calls or a user accessing premium content, Solana enables instant, low-cost payments that provides stable, predictable pricing for global services. Further, its low latency makes it easy to add layers like escrow and dispute resolution without noticeably increasing transfer time.

Powering the Agent Economy

AI is no longer confined to generating text or images. Improvements in tool use and context protocols have accelerated the ability of agents to effectively use tools and work on tasks with minimal human intervention. Agents will pay for services, fund their compute, manage subscriptions, and take action on behalf of their users in an increasingly independent fashion. This shift signals the rise of agentic payments, a new layer of the internet economy where machine to machine transactions make up a growing portion of services demand. Today these volumes are early, but growing. Since the launch of x402 on Solana this summer, we have seen 35M+ transactions and $10M+ volumes processed over x402. For this economy to scale, it needs rails that are fast, final, and built for autonomy. That is what x402 on Solana provides.

A Growing Ecosystem

The x402 community spans partners building everything from client SDKs to payment facilitators. Major platforms like Cloudflare, Google, and Vercel support x402, while teams are building early applications with growing userbases and volumes. Developers are creating MCP servers that connect AI models to x402 services, building payment infrastructure for agent marketplaces, and launching tools that make integrating any API effortless.

Real-World Use Cases

• →AI agents autonomously paying for API access, data feeds, and compute resources
• →Developer APIs monetized per-request without subscription complexity
• →Content creators charging micropayments for articles, images, or model inference
• →Agent marketplaces where autonomous buyers and sellers transact 24/7