# x402

> An open standard for internet-native payments that revives HTTP 402 Payment Required: the server responds 402, the client pays instantly with stablecoins and retries.

- Category: Tools & Protocols
- Stage: Rising
- Also called: HTTP 402 payments, x402 protocol
- Canonical: https://www.joelcsaji.com/ai-dictionary/x402

## Plain English

A website can charge an agent a fraction of a cent per call with no accounts or API keys - the money rides on the HTTP status code.

## Example

An agent hits a data API without a key, gets 402 plus payment instructions, settles $0.001 in stablecoin, retries, and receives the payload.

## Why it matters

The machine-payable complement to mandate-style agent commerce protocols - the natural monetization primitive for agent-consumed APIs and pay-per-crawl content.

## Related

- [Agentic Commerce](https://www.joelcsaji.com/ai-dictionary/agentic-commerce)
- [Agent Payments Protocol](https://www.joelcsaji.com/ai-dictionary/agent-payments-protocol)
- [Universal Commerce Protocol](https://www.joelcsaji.com/ai-dictionary/universal-commerce-protocol)

## Sources

- [x402 Protocol](https://x402.org/)