> For the complete documentation index, see [llms.txt](https://docs.granite.world/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.granite.world/introduction/stacks-sbtc-usdcx-aeusdc/stacks.md).

# Stacks

Granite is built on Stacks, a Bitcoin L2 that enables smart contract functionality while inheriting Bitcoin’s security. Applications in Stacks are written in Clarity, a smart contracting language specifically designed for high-stakes DeFi applications. Clarity prioritizes predictability and security through limited expressivity, which reduces the attack surface and prevents common smart contract vulnerabilities like re-entrancy attacks. It also includes post conditions and human-readable code on the blockchain, providing an additoinal layer of user protections.

Learn more about:

* [Stacks](https://stacks.co/)
* [Clarity](https://clarity-lang.org/)