> For the complete documentation index, see [llms.txt](https://docs.nubit.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nubit.org/utxo-bundling/introduction/how-it-works.md).

# How It Works

Step 1: Create a Bundle

Select a set of UTXOs. These might represent different amounts or origins, that’s okay.

Step 2: Apply a Key Tweak

A cryptographic tweak modifies the spending keys tied to those UTXOs. This tweak creates a secret offset that only the sender and recipient know.

Step 3: Share the Tweak

The recipient receives the tweak (or its derived key) and now holds the exclusive ability to spend the bundle.

Step 4: Optional On-Chain Action

The bundle can sit untouched indefinitely or be spent on-chain later, using the tweaked key, fully compatible with Bitcoin's native rules.