> For the complete documentation index, see [llms.txt](https://mogami.gitbook.io/mogami/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mogami.gitbook.io/mogami/learning/useful-links.md).

# Useful links

* [Official documentation](https://x402.gitbook.io/x402)
* [X402 GitHub](https://github.com/coinbase/x402)
* [White paper](https://www.x402.org/x402-whitepaper.pdf)
* [Specifications](https://github.com/coinbase/x402/blob/main/specs/schemes/exact/scheme_exact_evm.md)
* [Examples](https://github.com/coinbase/x402/tree/main/examples/typescript)
* [CDP faucet](https://portal.cdp.coinbase.com/products/faucet)
* [Circle faucet](https://faucet.circle.com/)
* [Base Sepolia Testnet Explorer](https://sepolia.basescan.org/)