Celo DeFi Integration

This skill covers integrating DeFi protocols on Celo, including Uniswap for swaps, Aave for lending/borrowing, and other protocols.

When to Use

• Building swap functionality with Uniswap or Ubeswap
• Integrating lending/borrowing with Aave
• Creating liquidity provision features
• Building DeFi aggregators

DeFi Protocols on Celo

Decentralized Exchanges

Protocol	Description
Uniswap V3/V4	Primary DEX with concentrated liquidity
Ubeswap	Celo-native DEX, mobile-optimized
Velodrome	Superchain DEX with liquidity mining
Carbon DeFi	Orderbook-like automated trading

Lending & Borrowing

Protocol	Description
Aave V3	Decentralized lending (launched March 2025)
Credit Collective	On-chain private credit for RWAs
PWN	Fixed-rate lending

DEX Aggregators

Protocol	Description
LI.FI	Cross-chain aggregator

Liquidity & Yield

Protocol	Description
Steer Protocol	Automated liquidity strategies
Merkl	Liquidity provider rewards

Uniswap V3 Integration

Contract Addresses - Mainnet (Chain ID: 42220)

Contract	Address
Factory	0xAfE208a311B21f13EF87E33A90049fC17A7acDEc
SwapRouter02	0x5615CDAb10dc425a742d643d949a7F474C01abc4
QuoterV2	0x82825d0554fA07f7FC52Ab63c961F330fdEFa8E8
NonfungiblePositionManager	0x3d79EdAaBC0EaB6F08ED885C05Fc0B014290D95A
UniversalRouter	0x643770E279d5D0733F21d6DC03A8efbABf3255B4
Permit2	0x000000000022D473030F116dDEE9F6B43aC78BA3
TickLens	0x5f115D9113F88e0a0Db1b5033D90D4a9690AcD3D
Multicall2	0x633987602DE5C4F337e3DbF265303A1080324204

Contract Addresses - Alfajores Testnet

Contract	Address
Factory	0x229Fd76DA9062C1a10eb4193768E192bdEA99572
SwapRouter02	0x8C456F41A3883bA0ba99f810F7A2Da54D9Ea3EF0
QuoterV2	0x3c1FCF8D6f3A579E98F4AE75EB0adA6de70f5673
NonfungiblePositionManager	0x0eC9d3C06Bc0A472A80085244d897bb604548824
UniversalRouter	0x84904B9E85F76a421223565be7b596d7d9A8b8Ce
Permit2	0x000000000022D473030F116dDEE9F6B43aC78BA3

Simple Swap Example

import { createWalletClient, custom, encodeFunctionData } from "viem";
import { celo } from "viem/chains";

const SWAP_ROUTER = "0x5615CDAb10dc425a742d643d949a7F474C01abc4";

const SWAP_ROUTER_ABI = [
  {
    name: "exactInputSingle",
    type: "function",
    stateMutability: "payable",
    inputs: [
      {
        name: "params",
        type: "tuple",
        components: [
          { name: "tokenIn", type: "address" },
          { name: "tokenOut", type: "address" },
          { name: "fee", type: "uint24" },
          { name: "recipient", type: "address" },
          { name: "amountIn", type: "uint256" },
          { name: "amountOutMinimum", type: "uint256" },
          { name: "sqrtPriceLimitX96", type: "uint160" },
        ],
      },
    ],
    outputs: [{ type: "uint256" }],
  },
] as const;

async function swapExactInput(
  tokenIn: string,
  tokenOut: string,
  amountIn: bigint,
  amountOutMin: bigint,
  fee: number = 3000
): Promise<string> {
  const walletClient = createWalletClient({
    chain: celo,
    transport: custom(window.ethereum),
  });

  const [address] = await walletClient.getAddresses();

  const hash = await walletClient.sendTransaction({
    account: address,
    to: SWAP_ROUTER,
    data: encodeFunctionData({
      abi: SWAP_ROUTER_ABI,
      functionName: "exactInputSingle",
      args: [
        {
          tokenIn: tokenIn as `0x${string}`,
          tokenOut: tokenOut as `0x${string}`,
          fee,
          recipient: address,
          amountIn,
          amountOutMinimum: amountOutMin,
          sqrtPriceLimitX96: 0n,
        },
      ],
    }),
  });

  return hash;
}

Ubeswap Integration

Celo-native DEX with V2 and V3 support.

Contract Addresses - Mainnet

Contract	Address
V3 Factory	0x67FEa58D5a5a4162cED847E13c2c81c73bf8aeC4
V3 Universal Router	0x3C255DED9B25f0BFB4EF1D14234BD2514d7A7A0d
V3 NFT Position Manager	0x897387c7B996485c3AAa85c94272Cd6C506f8c8F
V2 Factory	0x62d5b84bE28a183aBB507E125B384122D2C25fAE
V2 Router	0xE3D8bd6Aed4F159bc8000a9cD47CffDb95F96121
UBE Token	0x71e26d0E519D14591b9dE9a0fE9513A398101490

Aave V3 Integration

Contract Addresses - Mainnet

Contract	Address
Pool	0x3E59A31363E2ad014dcbc521c4a0d5757d9f3402
PoolAddressesProvider	0x9F7Cf9417D5251C59fE94fB9147feEe1aAd9Cea5
PoolConfigurator	0x7567E3434CC1BEf724AB595e6072367Ef4914691
Oracle	0x1e693D088ceFD1E95ba4c4a5F7EeA41a1Ec37e8b
ACLManager	0x7a12dCfd73C1B4cddf294da4cFce75FcaBBa314C
PoolDataProvider	0x2e0f8D3B1631296cC7c56538D6Eb6032601E15ED
Collector	0xC959439207dA5341B74aDcdAC59016aa9Be7E9E7

Supported Assets

Asset	Address	aToken
USDC	0xcebA9300f2b948710d2653dD7B07f33A8B32118C	0xFF8309b9e99bfd2D4021bc71a362aBD93dBd4785
USDT	0x48065fbbe25f71c9282ddf5e1cd6d6a887483d5e	-
USDm	0x765de816845861e75a25fca122bb6898b8b1282a	-
EURm	0xd8763cba276a3738e6de85b4b3bf5fded6d6ca73	-
CELO	0x471EcE3750Da237f93B8E339c536989b8978a438	-
WETH	0xD221812de1BD094f35587EE8E174B07B6167D9Af	-

Supply Assets

const AAVE_POOL = "0x3E59A31363E2ad014dcbc521c4a0d5757d9f3402";

const POOL_ABI = [
  {
    name: "supply",
    type: "function",
    stateMutability: "nonpayable",
    inputs: [
      { name: "asset", type: "address" },
      { name: "amount", type: "uint256" },
      { name: "onBehalfOf", type: "address" },
      { name: "referralCode", type: "uint16" },
    ],
    outputs: [],
  },
] as const;

async function supplyToAave(asset: string, amount: bigint): Promise<string> {
  const walletClient = createWalletClient({
    chain: celo,
    transport: custom(window.ethereum),
  });

  const [address] = await walletClient.getAddresses();

  // First approve the Pool to spend tokens
  const hash = await walletClient.writeContract({
    address: AAVE_POOL,
    abi: POOL_ABI,
    functionName: "supply",
    args: [asset as `0x${string}`, amount, address, 0],
  });

  return hash;
}

Borrow Assets

const POOL_ABI_BORROW = [
  {
    name: "borrow",
    type: "function",
    stateMutability: "nonpayable",
    inputs: [
      { name: "asset", type: "address" },
      { name: "amount", type: "uint256" },
      { name: "interestRateMode", type: "uint256" },
      { name: "referralCode", type: "uint16" },
      { name: "onBehalfOf", type: "address" },
    ],
    outputs: [],
  },
] as const;

async function borrowFromAave(
  asset: string,
  amount: bigint,
  interestRateMode: number = 2 // 2 = variable rate
): Promise<string> {
  const walletClient = createWalletClient({
    chain: celo,
    transport: custom(window.ethereum),
  });

  const [address] = await walletClient.getAddresses();

  const hash = await walletClient.writeContract({
    address: AAVE_POOL,
    abi: POOL_ABI_BORROW,
    functionName: "borrow",
    args: [asset as `0x${string}`, amount, BigInt(interestRateMode), 0, address],
  });

  return hash;
}

Token Approval

Before interacting with DeFi protocols, approve token spending:

const ERC20_ABI = [
  {
    name: "approve",
    type: "function",
    stateMutability: "nonpayable",
    inputs: [
      { name: "spender", type: "address" },
      { name: "amount", type: "uint256" },
    ],
    outputs: [{ type: "bool" }],
  },
] as const;

async function approveToken(
  token: string,
  spender: string,
  amount: bigint
): Promise<string> {
  const walletClient = createWalletClient({
    chain: celo,
    transport: custom(window.ethereum),
  });

  const [address] = await walletClient.getAddresses();

  const hash = await walletClient.writeContract({
    address: token as `0x${string}`,
    abi: ERC20_ABI,
    functionName: "approve",
    args: [spender as `0x${string}`, amount],
  });

  return hash;
}

Fee Tiers (Uniswap V3)

Fee	Use Case
100 (0.01%)	Stable pairs (USDm/USDC)
500 (0.05%)	Stable pairs
3000 (0.3%)	Most pairs
10000 (1%)	Exotic pairs

Dependencies

{
  "dependencies": {
    "viem": "^2.0.0"
  }
}

For Aave integration:

{
  "dependencies": {
    "@bgd-labs/aave-address-book": "^4.0.0"
  }
}

Additional Resources

• contract-addresses.md - All DeFi contract addresses