# DeFi Protocols

Rome enables EVM DeFi protocols to compose with Solana's native DeFi ecosystem atomically. This page covers common integration patterns.

## Why DeFi on Rome?

* **Access Solana liquidity** — Jupiter, Kamino, Drift, Meteora, Raydium, Orca
* **Atomic composability** — multi-step DeFi operations in a single transaction
* **Solidity tooling** — familiar development and audit ecosystem
* **Single state** — EVM and Solana users share the same pools

## Pattern 1: Lending Protocol with Solana Oracles

```solidity
import {IAggregatorV3Interface} from "@rome-protocol/solidity-sdk/contracts/oracle/IAggregatorV3Interface.sol";

contract RomeLending {
    IAggregatorV3Interface public priceFeed;

    constructor(address _priceFeed) {
        priceFeed = IAggregatorV3Interface(_priceFeed);
    }

    function getCollateralValue(uint256 amount) public view returns (uint256) {
        (, int256 price,,,) = priceFeed.latestRoundData();
        // Pyth/Switchboard price via Oracle Gateway
        // Same interface as Chainlink on Ethereum
        return (amount * uint256(price)) / 1e8;
    }
}
```

## Pattern 2: DEX Aggregator via CPI

```solidity
contract RomeSwap {
    function swap(
        bytes32 fromMint,
        bytes32 toMint,
        uint256 amount,
        uint256 minOut
    ) external {
        // CPI to Jupiter/Raydium/Meteora
        // All Solana DEX liquidity accessible from Solidity
        CpiProgram.invoke(JUPITER_PROGRAM, accounts, swapData);
    }
}
```

## Pattern 3: Yield Vault

```solidity
contract YieldVault {
    function deposit(uint256 amount) external {
        // Accept USDC deposit
        // CPI → Jupiter: swap to optimal tokens
        // CPI → Kamino: supply as collateral
        // CPI → Drift: open delta-neutral hedge
        // All atomic — one tx, all-or-nothing
    }
}
```

## Pattern 4: Cross-Protocol Arbitrage

Using `RemusTx` (atomic cross-rollup transactions):

1. Buy on DEX A in rollup 1
2. Sell on DEX B in rollup 2
3. Both atomically — zero execution risk

## Related

* [DeFi Composer](/products/defi-composer.md) — multi-protocol vault infrastructure
* [Oracle Gateway](/products/oracle-gateway.md) — Chainlink-compatible price feeds
* [Rome SDK](/products/rome-sdk.md) — typed interfaces for DeFi protocols


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.rome.builders/use-cases/defi-protocols.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.