BTCFi on Rootstock means lending, borrowing, yield, and liquidity apps that use rBTC and other assets on an EVM-compatible chain anchored to Bitcoin.

This section is for **builders** who implement strategies and vault integrations. **Who may use a live vault product** depends on the program, jurisdiction, and whether access is institutional, retail, or partner-only.

<!-- On Rootstock, users can earn yield, provide liquidity, and borrow against their Bitcoin without ever giving up the security of the Bitcoin network.

## The Purpose: Why BTCFi?
For years, Bitcoiners had to choose between holding their BTC securely or wrapping it on centralized exchanges to earn interest. BTCFi on Rootstock removes this trade-off by providing decentralized, smart-contract-based financial services that are anchored directly to [Bitcoin’s hash power](https://stats.rootstock.io).

## The Role of Rootstock

Rootstock serves as the **Smart Contract Engine** that unlocks Bitcoin's utility for the Bitcoin network.
* **Security:** It uses **Merged Mining**, meaning over 80% of Bitcoin miners secure Rootstock simultaneously with the main chain.
* **Compatibility:** It is fully **EVM-compatible**, allowing developers to use proven DeFi tools (Solidity, OpenZeppelin, Foundry, Hardhat, etc.) on top of Bitcoin.
* **Peg Stability:** The **PowPeg** ensures that every 1 rBTC on Rootstock is backed by exactly 1 BTC on the Bitcoin network.

> By using a [two-way peg (PowPeg)](/concepts/powpeg/), native BTC is locked on the Bitcoin network and an equivalent amount of **rBTC** is released on Rootstock. This rBTC is the lifeblood of BTCFi, allowing you to use Bitcoin's value with Ethereum-style smart contract flexibility.

## Technical Architecture
When building BTCFi dApps, you are interacting with the **Rootstock Virtual Machine (RVM)**. Because the RVM is fully EVM-compatible, you can use industry-standard tools like **Foundry, Hardhat, and OpenZeppelin** to manage Bitcoin-native assets.

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## Core pillars

| Pillar | Description | Where to go |
| :--- | :--- | :--- |
| **Vaults SDK** | ERC-4626 style flows for the USDRIF vault on Rootstock. | [Integrate USDRIF Vault](/use-cases/btcfi-finance-yield/yield-vaults-sdk/). Install and API details stay in the [Vaults SDK README](https://github.com/rsksmart/vaults-sdk). |
| **Stable units of account** | USD-pegged assets such as USDRIF for pricing and debt. | [RIF On Chain](https://rifonchain.com/) |
| **Liquidity and credit** | Lending and borrowing markets on top of rBTC and stable assets. | Protocol documentation for the venues you integrate (for example [Tropykus](https://app.tropykus.com/), [Money on Chain](https://moneyonchain.com/)) |


## Key Concepts

### 1. rBTC (Bitcoin-pegged gas and collateral)

rBTC is the native asset on Rootstock. It is pegged 1:1 with BTC through the PowPeg. When you [peg in](/resources/guides/powpeg-app/pegin/), BTC is locked on Bitcoin and rBTC is available on Rootstock. You pay gas in rBTC and use it as collateral in DeFi protocols.

### 2. USDRIF and stablecoins

Bitcoin is volatile, so many apps need a stable unit of account. **USDRIF** is a decentralized, USD-pegged asset with Bitcoin-backed collateral. Read the issuer and pool documentation before you integrate it in production.

### 3. Liquid staking (LSTs)

Some protocols issue receipt tokens when you stake rBTC (for example `st-rBTC`). Behavior, rewards, and risk depend on each protocol. Read the contract and liquidation rules before you treat an LST as collateral elsewhere.

## Tools developers use

* **Vaults SDK:** Yield and vault UX on Rootstock.
* **Money on Chain:** Bitcoin-backed stablecoins and leverage products.
* **Tropykus:** Lending and borrowing markets.

## Implementation guides

When you publish a guide in this folder (remove the leading `_` from the filename), it appears as a card below. Until then this section stays empty.