Trading Koinos via Ethereum Bridge (Goerli ETH to Koinos Harbinger Testnet)

Community Developer Roamin (twitter has created a bridge between Ethereum Goerli Testnet and Koinos Testnet. This bridge also works for BNB chain and AVAX c-chain.

  1. Set your Metmask to the Goerli test network loated at the top middle of the metamask . If you don’t see it, you need to unhide testnets.

  2. Set your Kondor RPC to To do this:

  • Right click on Kondor extension and click manage extension
  • Then select extension options.
  • Once you set the RPC, click Set RPC Nodes to lock it in.
  • You must also erase the Chain ID and then click Set Chain Id to set it as blank.
    Once this is complete, you should see Koinos Testnet on the top right corner of Kondor.
  1. Now you need test ETH, which you can get it from within this link: Faucet Link. You may need to jump through some hoops to get goerli test ETH because it is run by volunteers and there aren’t many of them. For example, in the screen shot below one, I can only get 0.2 test ETH a day, and I need to join a telegram channel and do some verification. It shouldn’t take you more than 2 minutes and does not require an email.

  2. Now you need to swap goerli test ETH with goerli wrapped ETH. Head over to to make the swap and also make sure you set Metamask on Goerli. Don’t wrap too much, you still need to pay for those darn gas fees! Leaving behind 0.01 test ETH should be good enough.

  3. Once you have your wETH, head over to

  • Section 1 connects Metamask and Kondor to set your addresses in the app.

  • Section 2 allows you to select the source chain. Choose Ethereum to transfer assets from Ethereum to Koinos. Else, choose Koinos to transfer assets from Koinos to Ethereum.

  • Section 3 allows you to choose which asset you want to transfer. Choose Wrapped Ether (wETH) if you want to send wETH or Koin. If you dont have the right asset in the source chain, an error will tell you have an insufficient balance.

  • Section 4 allows you to choose the amount to transfer (the minimum amount that can be bridged for any asset is 0.00000001 which is 8 decimals or 1 satoshi).

  • Section 5 is automatically filled in after you connect your wallet. If this isn’t right, go back to step 1.

  • You most likely will have to approve the token transfer first, so click on Approve token transfer (and go through the transaction approval)

  • Step 6: Once the approval is completed, click on Initiate transfer (and go through the transaction approval)


  • once the transfer is initiated, you should see the Ethereum transaction id in the Complete transfer step, for this step you need to wait for the validators to approve and sign the transfer. This takes 15 Ethereum blocks (a few minutes).


  • If you click complete transfer and didn’t wait long enough, you will see this error:

  • Otherwise if the transfer has been validated you can click Complete Transfer and you should see a Kondor window popup that will ask you to sign the last transaction that will release the token on the Koinos testnet. Confirm the transaction and you should get a transfer completed confirmation.

  1. To check if your wETH showed up in your Koinos Wallet, we need to inspect the wETH smart contract on Koinos by going to Koinosblocks.


  1. If you do the inverse and send tKOIN to Ethereum, you need to add a custom token into metamask using this smart contract address: 0xeA756978B2D8754b0f92CAc325880aa13AF38f88

Thats it! Yes, its a bit complicated if you are not use to using bridges, but that’s why we use test net to practice!

Here’s a summary of addresses for reference if you want to snoop around:

    $tKOIN on Ethereum: 0xeA756978B2D8754b0f92CAc325880aa13AF38f88
    $tKOIN on Koinos: 19JntSm8pSNETT9aHTwAUHC5RMoaSmgZPJ
    $wETH on Ethereum: 0xB4FBF271143F4FBf7B91A5ded31805e42b2208d6
    $wETH on Koinos: 1KazZFUnZSLjeXq2QrifdnYqiBvA7RVF3G