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

# For Builders

**How do I start building on Fractal?**

Visit [docs.fractalbitcoin.io](https://docs.fractalbitcoin.io/doc/developer-home) to access developer guides, tutorials, and API references. You can launch CAT20 tokens, build with OP\_CAT, and integrate BRC-20 and Runes natively.

**What are CAT20 tokens?**

CAT20 is a Fractal-native token standard that supports expressive, Bitcoin-compatible smart contracts using OP\_CAT. It allows programmable logic, dynamic asset issuance, and secure user flows — all within Bitcoin’s UTXO model.

[→ Read more on CAT](https://fractalbitcoin.io/learn/understanding-cat-protocol)

**Can I port my dApp from Ethereum or Solana?**

Fractal doesn’t run EVM code, but many application patterns — such as swaps, vaults, or staking — can be replicated using OP\_CAT and covenant logic. Fractal is more expressive than Ethereum in some dimensions and more minimal by design.

**What kind of apps can I build on Fractal?**

Builders have launched:

* Decentralized exchanges (PizzaSwap)
* Runes & Ordinals marketplaces
* zk-based verifiers and atomic swaps
* Infrastructure for OP\_CAT scripting
* On-chain games and virtual economies

Head on to <https://fractalecosystem.io/>- the community-driven ecosystem directory to explore more.