> For the complete documentation index, see [llms.txt](https://docs.vialabs.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vialabs.io/supported-protocols/proto-usd.md).

# Proto-USD

<figure><img src="/files/KEbty9AtJ592TcOYz9DD" alt=""><figcaption></figcaption></figure>

Proto-USD is a cross-chain protocol that enhances and extends the capabilities of Circle’s [Cross-Chain Transfer Protocol](https://www.circle.com/en/cross-chain-transfer-protocol) (CCTP). It allows blockchains without native CCTP support to seamlessly transfer USDC across networks, unifying liquidity and simplifying the user experience by enabling cross-chain transfers from any Proto-USD-enabled blockchain.