Bridging

Bridging to Celo

This skill covers bridging assets between Celo and other blockchains, including native bridges and third-party solutions.

When to Use

• Transferring assets from Ethereum to Celo
• Bridging tokens from Celo to other chains
• Integrating cross-chain functionality
• Building multi-chain applications

Bridge Options

Native Bridge

Native bridge provides direct transfers between Celo L2 and Ethereum L1 via the OP Stack standard bridge.

Source: https://docs.celo.org/tooling/bridges

Third-Party Bridges

Source: https://docs.celo.org/home/bridged-tokens/bridges

Native ETH Bridging

Bridge native ETH from Ethereum to Celo as WETH.

Contract Addresses

Ethereum Mainnet → Celo:

Sepolia Testnet → Celo Sepolia:

Bridge ETH to Celo

import { createWalletClient, custom, parseEther } from "viem";
import { mainnet } from "viem/chains";

const SUPERBRIDGE_WRAPPER = "0x3bC7C4f8Afe7C8d514c9d4a3A42fb8176BE33c1e";

const WRAPPER_ABI = [
  {
    name: "wrapAndBridge",
    type: "function",
    stateMutability: "payable",
    inputs: [
      { name: "_minGasLimit", type: "uint32" },
      { name: "_extraData", type: "bytes" },
    ],
    outputs: [],
  },
] as const;

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

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

  const hash = await walletClient.writeContract({
    address: SUPERBRIDGE_WRAPPER,
    abi: WRAPPER_ABI,
    functionName: "wrapAndBridge",
    args: [200000, "0x"],
    value: parseEther(amount),
  });

  return hash;
}

Natively Bridged Tokens

These tokens have official bridges from Ethereum via native bridge:

Source: https://docs.celo.org/home/bridged-tokens

Cross-Chain Messaging Protocols

For building cross-chain dApps:

Source: https://docs.celo.org/tooling/bridges/cross-chain-messaging

Using LI.FI SDK

For cross-chain swaps and bridges:

import { createConfig, getQuote, executeRoute } from "@lifi/sdk";

// Initialize LI.FI
createConfig({
  integrator: "your-app-name",
});

// Get bridge quote
const quote = await getQuote({
  fromChain: 1, // Ethereum
  toChain: 42220, // Celo
  fromToken: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", // USDC on Ethereum
  toToken: "0xcebA9300f2b948710d2653dD7B07f33A8B32118C", // USDC on Celo
  fromAmount: "1000000000", // 1000 USDC (6 decimals)
  fromAddress: userAddress,
});

// Execute the bridge
const result = await executeRoute(quote, {
  updateRouteHook: (route) => {
    console.log("Route updated:", route);
  },
});

Bridge Considerations

Security

• Native bridges (Superbridge) are the most secure
• Third-party bridges rely on their own security models
• Always verify contract addresses before bridging

Timing

• Native L1→L2 bridges: ~15-20 minutes
• L2→L1 withdrawals: 7 days (challenge period)
• Third-party bridges: varies (minutes to hours)

Fees

• Native bridges: gas fees only
• Third-party bridges: gas + bridge fees

Dependencies

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

For LI.FI integration:

{
  "dependencies": {
    "@lifi/sdk": "^3.0.0"
  }
}

Additional Resources

• bridge-contracts.md - All bridge contract addresses
• bridged-tokens.md - Complete list of bridged tokens