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Bridge Tokens with Etherscan

Bridging ERC-20 tokens from Ethereum and Polygon to Celo.

How to complete this guide#

  • Step 1: Approve the Bridge (for token usage)
  • Step 2: Call the Bridge (to send tokens)
  • Step 3: Wait

Step 1: Approve the Bridge#

Start by approving token usage on the bridge.

  1. Navigate to the Etherscan page for the token you want to send
  2. Open the Write Contract pane > connect your wallet > and select approve

Bridging Tokens with Etherescan 1

  1. For spender enter the BridgeRouter address:
tip

If you're unsure, check the decimals in the Read Contract pane

  • On Ethereum: 0x6a39909e805A3eaDd2b61fFf61147796ca6aBB47
  • On Polygon: 0xf244eA81F715F343040569398A4E7978De656bf6
  1. For amount enter the number of tokens you'd like to send in that token's smallest unit.
info

If you're unsure, check the decimals in the Read Contract pane

  • For most tokens the number of digits is 18
  • The + button next will help you fill in the right number
info

Approving too much is usually ok, but not approving enough will cause your next transaction to fail.

  1. Select write > sign the transaction > then send it to the network.

Step 2: Call the Bridge#

You can now start sending tokens on the approved Bridge.

  1. Navigate to the Etherscan page for the router
info
  • On Ethereum: 0x6a39909e805A3eaDd2b61fFf61147796ca6aBB47
  • On Polygon: 0xf244eA81F715F343040569398A4E7978De656bf6
  1. Open the Write as Proxy pane > connect your wallet > and select send

Bridging Tokens with Etherescan 2

  1. For _token, enter the address of the token you want to send
  2. For _amount, enter the amount of tokens you'd like to send in that token's smallest unit.
info

This should be the same number you approved earlier.

  1. For _destination, enter the domain ID of the chain to which you'd like to send tokens.
info

Domain IDs are like phone numbers. They represent the chain you're going to call:

  • 1667591279 for Celo
  • 1886350457 for Polygon
  • 6648936 for Ethereum
  1. For _recipient, enter the address of the recipient on the destination chain.
    • To help support future chains with longer addresses, Optics uses 32-byte addresses.
    • To convert an Ethereum, Celo, or Polygon address to bytes32 you can add 24 0s after the 0x prefix
tip

Before:bytes32 0x6a39909e805A3eaDd2b61fFf61147796ca6aBB47

After: 24 Zeros after 0x Prefix 0x0000000000000000000000006a39909e805A3eaDd2b61fFf61147796ca6aBB47

  1. Select write > sign the transaction > then send it to the network.

Step 3: Wait#

Wait for a moment for your transaction to finalize on the network.