This quick guide will get your assets flowing from Binance Smart Chain to Ethereum and vice versa in a few simple steps
The Phantasma blockchain serves as the central hub for assets flowing across between BSC and Ethereum
Swapping assets from Binance Smart Chain to Ethereum
One-time setup
Step 1: In your Metamask wallet, ensure that you have ETH on Ethereum and BNB on Binance Smart Chain
→ This is needed to pay the gas fees on Ethereum and BSC. We recommend at least 3-4x a Uniswap trading fee worth of ETH, and $5 worth of BNB
Step 2: Download Ecto wallet here to facilitate your swaps Ecto wallet is quite similar to Metamask, and provides cross chain swapping capabilites.
→ You can also use the standalone Poltergeist wallet (not covered in this guide)
Step 3: Export your Metamask private key and import it into Poltergeist or Ecto
→ A detailed tutorial for basic Ecto functionality with screenshots and step by step instructions is available here
→ Step by step screenshot cross chain swapping tutorials for Ecto available here (BSC-Phantasma) and here (Phantasma-Ethereum)
Depositing funds to cover Ethereum & BSC gas fees
Step 4: In Ecto, select [Multi Chain] > [Transfer from Ethereum]. Click [send] next to ETH, choose an amount equal to at least 1.5x a Uniswap trading fee, and confirm. Wait until the [claim] button appears (requires 12 block confirmations on Ethereum), and click it.
→ You now have ETH on the Phantasma mainnet to pay Ethereum gas fees when you swap your token to Ethereum
Step 5: This is optional. In Ecto, select [Multi Chain] > [Transfer from BSC]. Click [send] next to BNB, choose an amount equal to at least $5, and confirm. Wait until the [claim] button appears (requires 12 block confirmations on BSC), and click it.
→ You now have BNB on the Phantasma mainnet to pay BSC gas fees is you later wish to swap your tokens back from Ethereum to BSC
Performing the asset swap
Step 6: In Ecto, select [Multi Chain] > [Transfer from BSC]. Click [send], choose your amount and confirm. Wait a few minutes until the [claim] button appears, and click it.
→ Your tokens are now on the Phantasma mainnet, ready to flow on to Ethereum
Step 7: In Ecto, select [Multi Chain] > [Transfer to Ethereum]. Click [select asset], choose your token, the amount you wish to swap and confirm. Wait a few minutes until the [claim] button appears, and click it.
→ Your tokens are now on Ethereum, and will be available in your Metamask wallet. If you can’t see them within 10 minutes, please double check that you have imported the Ethereum side contract address for your token (refer to the project issuing the token you swapped for the correct contract address)
Some additional notes
Swapping from Ethereum to BSC: If you later wish to swap your assets from Ethereum to Binance Smart Chain, simply perform step 6 and 7 above in the reverse order, ie [Transfer from Ethereum] and [Transfer to BSC].
A note on fees: Please be aware that Ethereum gas fees are extremely variable, from a few dollars to hundreds depending on the amount of traffic on the Ethereum blockchain. Ethereum gas fees are also prone to sudden spikes.
As a cross chain swap interacts with an Ethereum smart contract to trustlessly distribute your swapped funds to your wallet, the gas fee required is approximately the same as for a Uniswap trade. For this reason we always recommend swapping more ETH to the Phantasma mainnet than you think you will need.
If you expect to swap from Binance Smart Chain to Ethereum multiple times, it would be wise to swap additional ETH right away to save on later gas fees (due to not needing to swap ETH several times).