Key takeaways:
x402 provides pay-per-use functionality on the internet.
The current momentum is driven by infrastructure, led by Coinbase and Cloudflare.
PING was a catalyst, but the main focus is on protocol adoption, not the token itself.
You can quickly test it by creating an endpoint and verifying the 402 → pay → grant flow.
X402 is a simple method for enabling pay-per-use on the internet. When you access a paid application programming interface (API) or file, the server responds with the web’s built-in “402 Payment Required” message, detailing the cost — often just a few cents in USDC (USDC) — and the payment destination.
You make the onchain payment from your wallet, repeat the request, and the server provides the result. There are no accounts, passwords, API keys, or monthly subscriptions — just a one-time payment tied to that specific request.
The “second wave” of x402
The concept isn’t new. The 402 status code has existed in HTTP for years, but it lacked a workable framework until 2025, when Coinbase developed a clear protocol around it (“x402”). The company released documentation and code and provided a managed gateway for developers. Shortly thereafter, Cloudflare partnered with Coinbase to co-launch the x402 Foundation initiative, formalizing the standard and integrating support into mainstream developer tools.
You may have first learned of x402 through a token called PING, which garnered attention. Although the token hype faded, the protocol persisted because it addresses a widespread issue: charging per API call, per AI inference, or per download without requiring users to create accounts.
This utility, combined with new tools for AI agents capable of automatic payments, is driving a second wave focused on actual usage rather than price trends.
Did you know? X402 is becoming the default method for AI agents to make purchases autonomously. Cloudflare is incorporating native x402 support into its Agents SDK and MCP servers. Coinbase’s new Payments MCP enables popular large language models to maintain a wallet and fulfill requests without API keys.
What is PING, who’s behind it, and how does it relate to x402?
PING is a memecoin on Base (Coinbase’s layer 2). It became the first public token mint executed through an x402 flow, which is why it attracted attention. Early investors accessed a uniform resource locator (URL), received a “402 Payment Required” message, paid a small amount in USDC onchain, retried the request, and obtained PING. Consider it a live demonstration of x402’s pay-per-request model applied to minting.
The token was introduced by the X account Ping.observer. Public reports consistently credit PING to this account. There is no official team page or white paper beyond this, and no credible disclosures of VC backing specific to the PING token itself.
X402 facilitated the infrastructure, while PING acted as its first major test case. The token’s pay-to-mint mechanism stress-tested the protocol and highlighted x402’s core principle: charging a minimal onchain fee per request. This includes API calls, AI inferences, file downloads, or in this case, a mint, all without necessitating accounts or API keys.
After the initial surge and subsequent drop, the lasting impact was not the token price but the influx of developers and endpoints engaging with x402.
Did you know? PING achieved an all-time high of approximately $0.0776 on Oct. 25, 2025, before retracting in the following days.
How to try x402 (developer quick start)
1) Get the gist
X402 is a straightforward handshake. You call a paid URL, and the server responds with “402 Payment Required” and the price in USDC. You send the onchain payment, then call the URL again with the payment proof to retrieve the result. That’s all.
2) Choose your setup
Managed: Utilize Coinbase’s hosted x402 gateway with dashboards and built-in Know Your Transaction (KYT) checks. This is ideal for a quick proof of concept.
Do it yourself (DIY)/spec: Clone the open-source x402 reference implementation and run a basic seller and buyer locally for full control.
3) Expose one paid endpoint
Select any route (for instance, “/inference”). When someone accesses it without payment, return a “402” response along with the payment details, including the amount, asset (USDC), destination address, and expiry. If you can trigger that response using “curl,” you are correctly implementing x402.
4) Complete one paid request
Use the sample client or the managed gateway to identify the “402,” execute the onchain payment, and then retry the request. Access should update automatically once the payment is confirmed, without requiring accounts, API keys, or OAuth.
5) Optional: Test with an AI agent
If you work with agents, set up the model context protocol (MCP) example. The interceptor will detect the “402,” make the payment from the agent’s wallet, and automatically reissue the request. This is a quick way to validate agent-to-endpoint flows.
Top tip: Start on a testnet as detailed in the quickstart. Once the 402 → pay → grant loop is stable, switch the configuration to mainnet.
Risks, timelines, and what to watch next
What can still go wrong
X402 is still relatively new. The specification and reference code may continue to develop, and most operational setups currently use USDC. Over-reliance on a single managed gateway or a single asset entails both vendor and asset concentration risks. It’s also crucial to separate token narratives from protocol advancements.
Governance to track
Keep an eye out for the formal launch details of the x402 Foundation, including its charter, member list, and roadmap. This event will signal the protocol’s transition from a product to a standard. Additionally, monitor Cloudflare’s developer ecosystem (Agents SDK and MCP) as mainstream tools often emerge before widespread adoption.
Adoption signals
Look for real endpoints that return “402” responses with payment parameters, thereby unlocking access after an onchain payment, without requiring accounts or API keys in between. More quickstarts, documentation, and GitHub activity are positive indicators on the supply side.
Wider distribution across cloud services, Content Delivery Networks (CDNs), and agent frameworks beyond the initial partners, coupled with support for additional assets and networks, will make x402 increasingly important. Continued developments in “agentic commerce” integrations are also likely to attract developers who typically do not engage with crypto.
How to stay current
Follow the primary channels: Coinbase’s product pages, documentation, and GitHub for protocol updates, along with Cloudflare’s blog and press releases for foundation news and SDK support. Treat any information outside those sources, especially token discussions, as background noise.
This article does not contain investment advice or recommendations. Every investment and trading move involves risk, and readers should conduct their own research when making a decision.
