How to Borrow Against Native Bitcoin on Aave V4 with the Babylon Spoke

Overview

This tutorial explains the proposed Babylon-powered native BTC borrowing spoke for Aave V4—a new feature that would allow users to borrow against native Bitcoin (BTC) without relying on wrapped tokens (like WBTC) or centralized custodians. The proposal, currently in a governance temperature check phase, aims to integrate Babylon’s staking protocol into Aave’s V4 architecture. Once approved, users will be able to deposit native BTC directly into a dedicated “spoke” (a specialized smart contract on the Bitcoin network), which then communicates with Aave V4 on Ethereum or another chain via cross-chain messaging. This unlocks BTC’s liquidity for DeFi while preserving self-custody and censorship resistance. This guide walks through the envisioned process, prerequisites, and best practices for using this hypothetical feature.

Prerequisites

Wallet and Network Setup

• A non-custodial wallet that supports both Bitcoin and Ethereum (e.g., MetaMask with Bitcoin support via a sidechain or a multi-chain wallet like Rabby).
• Enough native BTC to deposit (minimum collateral amount determined by Aave V4 risk parameters).
• Ethereum account with ETH for gas fees (to interact with Aave V4 contracts).

Understanding Babylon and Aave V4

• Familiarity with Babylon: a Bitcoin staking protocol that allows BTC to be locked in a trust-minimized way to secure other blockchains. In this proposal, Babylon acts as the “spoke” that holds BTC and issues a representation of it on the Aave side.
• Knowledge of Aave V4: the next major upgrade of Aave, which introduces a modular architecture with cross-chain spokes.

Governance Approval

Before using, the proposal must pass Aave DAO’s governance process. This tutorial assumes the proposal is fully implemented and live. For the current status, check the Aave governance forum.

Step-by-Step Instructions

Step 1: Connect Your Wallet to Aave V4

1. Navigate to the Aave V4 interface (e.g., app.aave.com/v4).
2. Click “Connect Wallet” and select your multi-chain wallet.
3. Ensure you are on the correct network (Ethereum mainnet for the V4 hub; the spoke will handle Bitcoin side).

Step 2: Select the Babylon Spoke

1. In the Aave V4 dashboard, locate the “Spokes” section.
2. Choose “Babylon BTC Spoke” from the list. This directs your deposit action to the Bitcoin network via a cross-chain bridge.
3. You may need to approve the spoke contract in your wallet (a one-time permission).

Step 3: Deposit Native BTC

1. Click “Deposit” in the Babylon spoke panel.
2. Enter the amount of native BTC you wish to collateralize. The interface will show the equivalent in “aBTC” (Aave’s representation).
3. Send the BTC to the provided Bitcoin address (the spoke’s cold wallet or a smart contract). Important: Use only a native BTC transaction—not wrapped or sent via another chain.
4. Confirm the transaction on your Bitcoin wallet. Wait for confirmations (typically 6 blocks for security).

Step 4: Verify Collateral on Aave

1. After BTC confirmations, the Babylon spoke will relay a proof to Aave V4 via its cross-chain oracle.
2. Refresh the Aave dashboard. You should see your deposited BTC reflected as aBTC collateral with a specified loan-to-value (LTV) ratio (e.g., 70%).

Step 5: Borrow Against Your BTC

1. Go to the “Borrow” section of Aave V4.
2. Select the asset you want to borrow (e.g., USDC, ETH, DAI).
3. Enter the amount, ensuring your health factor remains above 1.0 (the liquidation threshold).
4. Review the interest rate model (stable or variable) and transaction fees.
5. Confirm the transaction on Ethereum—gas fees apply.

Step 6: Monitor and Manage Position

• Check your health factor regularly. It drops if the borrowed value increases relative to collateral (due to price fluctuations).
• To repay, use the “Repay” button in the same spoke interface.
• To withdraw BTC, first repay all borrowed assets, then use “Withdraw” to trigger a cross-chain release of your native BTC from Babylon spoke to your Bitcoin address.

Common Mistakes

Mistake 1: Using Wrapped Tokens

This spoke is designed for native BTC only. Depositing WBTC or renBTC will not work—it will be rejected by the contract. Always double-check you are sending from a native Bitcoin address, not an Ethereum-based token.

Mistake 2: Ignoring Cross-Chain Delays

Deposits and withdrawals require cross-chain communication, which can take minutes to hours (depending on Bitcoin block times and oracle finality). Plan accordingly—do not expect instant liquidity.

Mistake 3: Over-Leveraging

Because BTC is volatile, borrowing close to the maximum LTV (e.g., 70%) increases liquidation risk. A 10% drop in BTC price could trigger a liquidation event. Keep your health factor above 1.5 to be safe.

Mistake 4: Forgetting Gas Fees

Interacting with Aave V4 on Ethereum incurs gas fees in ETH. Ensure your wallet has enough ETH for both the approval and the borrow/repay transactions.

Mistake 5: Sending to Wrong Address

The Babylon spoke provides a unique deposit address. Never send BTC to a generic address—always verify the address in the Aave interface. A wrong address means lost funds.

Summary

The Babylon-powered native BTC borrowing spoke on Aave V4 promises to unlock Bitcoin’s vast liquidity for DeFi while maintaining full self-custody. This guide has covered the overview, prerequisites, and detailed steps to deposit native BTC, borrow against it, and manage the position. Key prerequisites include a multi-chain wallet, ETH for gas, and governance approval. Common pitfalls—using wrapped tokens, ignoring delays, over-leveraging, and sending funds incorrectly—must be avoided. As a temperature check proposal, the future of this feature depends on DAO votes; stay tuned to the Aave governance forum for updates.