Today, @coinbasedev is announcing x402: an open standard/protocol to bring onchain payments to the web. Join us in killing the API key, and making the agentic and payable web a reality. All in one line of code.

Imagine a future where crypto is the default to pay for *anything*.

Mainly posting from @coinbase. 

https://www.coinbase.com/developer-platform

Bringing a millions devs onchain.

Product Lead, Coinbase Developer Platform https://cdp.coinbase.com

Prev lead of USDC. Crypto class of 2014

It all starts with HTTP status code 402, payment required. Set aside for payments, it was never implemented.

For years, the crypto community has talked about bringing blockchain payments to the web. We think the moment is now.

Thousands of developers have used AgentKit, pairing an AI agent with a crypto wallet. But it's impossible for an AI agent to pay. And many agent use cases are commerce based.

AIs don't have credit cards. API keys are made for humans.  Enter 402.

With x402, agentic commerce is suddenly a reality. Your API can accept crypto, your paywall can accept crypto, your MCP server can accept crypto.

Blockchains are global, permissionsless, and programmable, the exact characteristics that make them perfect for machines.

The same technology can be used for micropayments, paywalls, and more. No fees, instantaneous settlement, no transaction minimums.

If you develop a website, check out our instructions:

The same technology can be used for micropayments, paywalls, and more. No fees, instantaneous settlement, no transaction minimums.

If you develop a website, check out our instructions: https://x402.gitbook.io/x402/getting-started/quickstart-for-sellers

In JS, it's one line of code:
app.use("/your-route", payMiddleware("$0.10", myAddress));

How it works:
- Client requests something
- Client gets a 402 response
- Client responds with a signed payment
- (Server does work and broadcasts transaction)
- Client gets response

This is just the start. We're going to keep building this standard in the open. Join us.

This is just the start. We're going to keep building this standard in the open. Join us.

https://www.x402.org/

Blockchains are finally fast, scaled, and cheap. Stablecoins bring stability and easy global adoption. Usability has improved a ton. Hundreds of millions are onchain.

Just as importantly, there's a critical use case for machine to machine payments: AI.