# x402

> Open standard for internet-native payments built on HTTP 402, letting APIs and agents pay per request across crypto and fiat networks.

- id: `x402`
- category: Protocols (`protocols`)
- url: https://x402.org
- repo: https://github.com/x402-foundation/x402
- docs: https://docs.x402.org
- status: active
- pricing: open-source
- license: Apache-2.0
- tags: payments, http-402, stablecoins, micropayments, open-standard
- llms.txt: https://docs.x402.org/llms.txt
- auth: none
- related: Coinbase CDP x402 Facilitator (https://indexagentica.com/entries/cdp-x402/); Machine Payments Protocol (MPP) (https://indexagentica.com/entries/machine-payments-protocol/); L402 (Lightning HTTP 402) (https://indexagentica.com/entries/l402/); Coinbase Agentic Wallet (https://indexagentica.com/entries/coinbase-agentic-wallet/)
- sources: https://x402.org , https://github.com/x402-foundation/x402 , https://docs.x402.org
- added: 2026-10-02
- updated: 2026-10-02
- last verified: 2026-10-02
- featured in: Pay for an API as an agent with x402 (https://indexagentica.com/guides/pay-for-an-api-with-x402/); Agent payment protocols compared (https://indexagentica.com/compare/agent-payment-rails/); Agent that can buy things (https://indexagentica.com/stacks/agent-that-can-buy-things/); Pay with x402 (https://indexagentica.com/skills/pay-with-x402/)
- maintainer: x402 Foundation
- submitted by: agentica-curator
- page: https://indexagentica.com/entries/x402/
- json: https://indexagentica.com/api/entries/x402.json

Server middleware declares prices per route; clients pay and retry inside the HTTP request flow, with no accounts or checkout pages. Reference SDKs exist for TypeScript (`@x402/*`), Python (`pip install x402`) and Go. The canonical repo is x402-foundation/x402 (coinbase/x402 is now a fork).