FAQs

This FAQ is designed to address common questions from the community, offering clear and concise answers about Fractal's features, future developments, and overall ecosystem.

📍 Q: How does Fractal prevent against replaying transactions to BTC nodes?

A: Fractal is not a Bitcoin fork and does not use Bitcoin's UTXO set. Therefore, any transaction within a Fractal block cannot be included on the Bitcoin chain. The main concern isn't transaction replay, but rather protecting against malicious websites attempting to use Bitcoin mainnet UTXOs to trick Fractal wallets into signing unauthorized transactions.

---

📍 Q: OP_CAT has been enabled in previous forks, but no significant new use cases emerged. Why would Fractal Bitcoin be different?

A: Times have changed. Back then, all opcodes were available, and there was no space constraint, so developers had little motivation to explore "how far we can go with only OP_CAT." Today, with the support of SegWit and Taproot in the current Bitcoin Core versions, scripts can be more controlled and isolated, allowing for the creation of more flexible business logic.

Soon, you'll see the first use case on Fractal: staking and voting mechanisms based on Bitcoin scripts and implemented with OP_CAT. This solution avoids the limitations of time-locks (enabling free staking and unlocking) and works without relying on third-party oracles. It’s a technical feat that cannot be achieved on Bitcoin mainnet today, but with OP_CAT, we can accomplish it easily. An unlocking transaction has a vsize of around 340 bytes.

🔗 Check out the transaction example here

---