Bridging EWT (Energy Web Chain) <-> EWTB (Ethereum)

Bridging EWT to EWTB

1. Using the bridge user interface, a user confirms the amount of EWT to be bridged to EWTB

2. The EWT are locked in a smart contract that is deployed on the Energy Web Chain.

3. On the Ethereum Mainnet, an equal value (minus the cost of gas) of EWTB are minted

4. The EWTB are released to the user's address on Ethereum Mainnet

Bridging EWTB to EWT

1. Using the bridge user interface, a user confirms the amount of EWTB to be bridged back to EWT

2. An amount of EWT corresponding to the number of EWTB being bridged are released to the user's wallet from the holding smart contract.

3. The corresponding EWTB on the Ethereum Mainnet are burned

Walkthrough of Energy Web Bridge Interface

1. Connect your MetaMask to the Energy Web Chain Network. For directions on how to do this, go here.

2. Navigate to https://bridge.energyweb.org/ and connect to MetaMask. Select the account that has the tokens you want to bridge. Once connected. you should see your EWT balance in the bridge under Energy Web Chain.

3. Click on the "Show More" link. Note that it specifies a maximum and minimum amount for a bridge transaction.

4. Input the amount of EWT to bridge. Note that some of this amount will go toward the gas fee to execute the transaction on the Ethereum Mainnet, so account for this in your total transfer amount

5. Click "Transfer"

6. Approve the transfer transaction in MetaMask

7. Change your MetaMask network to the Ethereum Mainnet

8. When the transaction goes through, you will see your EWTB balance in the same account that you initiated the bridge transaction from on the Ethereum Mainnet Network

Bridging

Native utility tokens are incompatible with other blockchains. You could liken them to a country's native currency. It has value and utility within a certain context, but to be used elsewhere it must first be exchanged for a currency that is accepted where you need to use it.

Native tokens must go through a similar process of conversion in order to be used on another blockchain other than their native blockchain. This process is known as transferring or 'bridging tokens', and it allows for token interoperability between blockchains that are otherwise incompatible. Tokens that are bridged and exist on a non-native blockchain are called "wrapped tokens."

Energy Web Token (EWT) is no different in that it is incompatible with other blockchains, and with some wallets and cryptocurrency exchanges. In order to be used outside of the Energy Web Chain, it needs to be bridged first by using a bridge. For example, if you want to bridge towards Ethereum Mainnet, you need to feed the bridge with an ERC20 compatible token that's implemented on the EWC blockchain. In order to bridge $EWT, the platform will automatically wrap the native utility token to the wrapped ERC20 version. ERC20, which is explained below, is a technical standard for tokens on Ethereum Virtual Machine (EVM) blockchains.

ERC20 Token Standard

The ERC20 is the technical standard for fungible tokens on EVM blockchains, like Ethereum Mainnet and Energy Web Chain. ERC20 is not a token itself; it is a smart contract that contains methods that determine how a token should behave. These methods cover specific actions like transferring funds, checking a balance and approving transactions. Tokens that implements these standards behave in an interoperable and predictable way.

ERC20 tokens have value and can be traded, but they are not associated with a specific blockchain. Compare this with a token like EWT that is associated with the Energy Web Chain, or ETH that is associated with the Ethereum blockchain.

You can read about the ERC20 standard and see all of it's methods on Ethereum’s documentation site here.

Need to bridge a token? Use these bridges

Bridging EWT to ERC20 Tokens

Bridging EWT to Ethereum Mainnet creates ERC20 tokens called Energy Web Token Bridged; its symbol is EWTB. EWTB can be bridged back to the Energy Web Chain and redeemed as EWT at any time.

There are several scenarios that necessitate bridging EWT to EWTB:

1. You want to send EWT to a wallet that does not accept EWT, but does accept ERC20 compatible tokens. Not all wallets recognize EWT.

2. You want to swap EWT on an exchange that does not accept EWT or only accepts ERC20 compatible tokens. Not all exchanges recognize EWT.

3. You want to use your EWT to make transactions (such as sending tokens or using decentralized applications deployed on Ethereum) on the Ethereum Mainnet.

4. You want to trade your EWT for other ERC20 compatible tokens on a decentralized platform that is running on Ethereum.

Bridging Process

The conversion of EWT to EWTB is managed by a smart contract that is deployed on the Energy Web Chain. You can view this contract here.

The AllianceBridge has successfully built out, tested and audited its seamless and fully decentralized blockchain interoperability platform and is now available on mainnet since July 12, 2021. You can use it here and view their announcement here.

AllianceBridge enables applications built on different blockchains to communicate with and interact with each other, something which was never before possible, therefore unlocks a groundbreaking development for the blockchain space as a whole. On launch, Energy Web, Ethereum, BSC, Avalanche, and Polygon — five of the leading blockchains and protocols — are supported, with capabilities to add new blockchains built-in to the AllianceBridge protocol.

Unlike most bridges that have a centralized relayer and/or have direct control over tokens (eg. using pools on each network so that they don’t need to wrap the tokens to bridge); AllianceBridge does everything completely decentralized, using the Hedera Consensus Services.

How is this different? AllianceBridge is governed by a set of validators. It has a novel synchronisation mechanism based on Hedera Hashgraph Consensus Service. This allows the validators to synchronise in a decentralized way instead of a heavy and slow “gossiping” protocol.

What impact will it have? This bridge will likely be cheaper and more effective compared to any other bridge due to the lowered technological overhead. It will enable more efficient interblockchain token (and in the future data) transfers. In addition, this will enable further synergy inside and outside AllianceBlock’s ecosystem, enabling more and more cross-chain integration and unique products.

Why is it open source? Open source drives the blockchain space forward. We are firm believers that an open code is beneficial for the project and for the community.

What are Validators? Starting with three validators, there is not one entity that has direct control of the tokens. Without centralized relayers, AllianceBridge is much more secure, faster and fully transparent. A validator, sometimes called a bridge operator, is a node observing the bridge’s transactions in the source network and signing it off so that the recipient network can safely receive these and create the wrapped tokens.

Currently, the Alliancebridge has three entities being bridge validators with the intention to add more entities:

• AllianceBlock

• LimeChain

• Faculty Group

Getting started

The AllianceBridge accepts $EWT

Using the bridge rewards the bridge validators with the Allianceblock token ($ALBT) or native Energy Web token ($EWT). Fees are kept as low as $1

Prerequisites

Make sure you have MetaMask installed and the Energy Web network added.

MetaMask will then popup, press "Approve" button to finalize adding the network to MetaMask. You don't have to switch network afterwards in case MetaMask asks.

Handling fees

In order to bridge tokens from one network to the other fees need to be paid two ways:

• Transaction fees to the network in their native token: - ETH for Ethereum Mainnet - EWT for Energy Web - MATIC for Polygon Network - AVA for Avalanche - BNB for Binance Smart Chain

• ALBT fees for the Bridge: - ALBT for Ethereum Mainnet - WALBT for all other networks (the bridged version of ALBT)

The transaction fees to the network are depending on the network itself and likely tied to how congested the network is or isn't. The transaction fees to the bridge are always set to 1 ALBT/WALBT. This means you will always need to have ALBT in your wallet in order to pay the bridging fees, no matter the token you bridge.

Important note: do not use the AllianceBridge to bridge tokens that are native on one of the supported networks.

For example, if you have ERC20 MATIC and you want to have native MATIC on the Polygon network in order to pay the fees for claiming the bridged tokens, you cannot bridge your ERC20 MATIC to Polygon, it would create wMATIC on the Polygon network, not the native MATIC token that is used to pay the fees. In order to bridge these native tokens, use officially supported bridges or buy them on the network itself.

List of ALBT token addresses on each network

• Ethereum Mainnet ALBT: 0x00a8b738E453fFd858a7edf03bcCfe20412f0Eb0

• Energy Web WALBT 0x78B745b71cd53347335BEC9A2601703AcF689162

• Binance Smart Chain WALBT: 0x42f3008F6945f052C31e7680F7f78c512099b904

• Polygon WALBT: 0x35b2ECE5B1eD6a7a99b83508F8ceEAB8661E0632

• Avalanche WALBT: 0x9E037dE681CaFA6E661e6108eD9c2bd1AA567Ecd

Bridging tokens

In order to show the steps needed in order to use the bridge, we will bridge ALBT from Ethereum Mainnet to Binance Smart Chain (also Mainnet). The steps will be the same as from any network to any other network, but we will take these two networks as a clear example.

Getting connected

First of all, make sure you go to the official AllianceBridge website at https://alliancebridge.io/. You will see the following appear:

In order to be able to connect a wallet, you will first need to select your starting network, so in this case, we will start with Ethereum, as we want to bridge from Ethereum to Binance Smart Chain. Click "Choose network" on the top right of the screen and then select "Ethereum Mainnet":

Then proceed by clicking Connect Wallet button next to where you selected the network:

MetaMask will pop up and will ask you with which wallet you would like to connect. Choose the wallet that has the ALBT that you want to bridge to Binance Smart Chain.

If everything is connected correctly, you should see the following (but with your wallet address):

Sending your tokens to the Bridge

A bit below you have several options, let's look at them step by step:

• The first part shows the current select network, which should be Ethereum Mainnet if you are following this tutorial step by step.

• The second part exists out of the "Send" and "Claim" buttons. When clicking one of those buttons, the user interface toggles between the Send and Claim interface, by default the Send interface is selected (as now). The Send interface is meant to send your tokens from the current network to your target network. The Claim interface is meant to get your tokens from the target network.

• The final part that is relevant to this step in the tutorial is to allow you to select the target network.

Let's change the target network (under "To") to "Binance Smart Chain":

Now it's time to look at the second part of the UI step by step again:

• The first part is the recipient, it's set by default to your current connected wallet. It's easiest to leave it like this so you don't have to switch wallets between networks.

• The second part is the amount of the token you want to bridge (with your current balance of that token above it) and then a dropdown you'll have to use in order to select the token you want to bridge.

• The buttons are to Approve the ALBT (to pay the fees), another Approve button for the Token you want to bridge (will disappear if you will bridge ALBT, as you would already need to approve it). Approving is important to allow the smart contract to spend the token from your wallet, otherwise, the transaction won't work. The last button is the Send button, which will actually bridge your token to the target network. Note: you'll only need to approve a token once per wallet.

As mentioned before, let's keep the recipient as it is and select ALBT as token to bridge. Click on "Select Token" and select ALBT:

The UI will now update and show your balance of ALBT:

Let's enter the amount of ALBT we want to bridge, in this example we will bridge 100 ALBT to get 100 WALBT. Once you input the 100 ALBT, you will see new information below with more information about the transaction you are about to make:

As stated before, you'll first need to approve the contract spending the ALBT, you can click the first "Approve ALBT" button and Confirm in MetaMask. Don't worry, you'll only have to click one, the second one will disappear automatically once the first one is completed.

You will see a loading indicator while the transaction is processing:

Once done, the second Approve button is disabled and the Send button gets enabled:

Let's press Send in order to send the tokens to the bridge to get ready for the last step, claiming the tokens from the target network! Confirm again in MetaMask and wait for the transaction to complete. You can also follow the transaction by clicking on the "Check transaction here" link below:

Claiming your tokens on the target network

Important note: in order to claim your tokens on the target network, you will need to have the target network's native token in order to pay for the transaction fees. In this example with BSC (Binance Smart Chain) being the target network, you will need BNB in your wallet on the BSC network. You cannot use the AllianceBridge to bridge BNB (or other "native" tokens that are used to pay network/transaction fees).

In order to claim your tokens, you will need to switch networks in the Bridge UI, MetaMask and change the Bridge UI to the Claim page, let's check this step by step:

• First, go to MetaMask and change network on top to Binance Smart Chain Mainnet:

• Then do the same in the Bridge UI (top right):

• And press the Connect Wallet button next to it:

• Now click the Claim button:

The UI will change below and should already show your bridged tokens. If you don't see the bridged tokens, it might take a few seconds before they show up (the UI auto-refreshes every 15 seconds). If still nothing, please check if you have connected the same wallet as you have specified in the "Recipient" field earlier.

Click the Claim button to execute the transaction to receive the bridged WALBT tokens in your wallet:

MetaMask will pop up, click confirm. The Claim button will then change into "Claiming…" until done:

Once done, the Claim/Claiming button will be greyed out:

You will now find your tokens in your wallet. Not sure how to see them? Open MetaMask, click the 3 vertically stacked dots on the top right and click "View in Explorer":

This will open the BSCScan website for your wallet. You can click the BEP-20 Token Txns tab and you will find that you have received your WALBT tokens!

That's it! You have successfully bridged ALBT from Ethereum to WALBT on BSC