Address Binding

What is address binding? Learn how to bind your Substrate account to your own EVM account.

Background

EVM+ is live on Acala and Karura and EVM wallet is required to access its feature - such as transferring ERC20 tokens. Acala's EVM+ has built in feature to auto-generate and auto-bind an EVM address to the Substrate (Polkadot) address when needed, so it is seamless for users to use EVM features. As there is no private key for the auto-generated account, this account can only be accessed through Polkadot address on supported Dapps such as Acala/Karura.

For users with existing EVM account and want to bind this account to the Polkadot address instead, this document describes the process for user to bind their own EVM account.

Video

Pre-Requisites

• MetaMask and Substrate Wallets, Substrate wallet not bound to any account.

• ACA in your Substrate Wallet and other tokens in your MetaMask wallet to pay for transaction fees.

You can learn how to create a Substrate wallet by following any of these guides. You can learn how to send ACA to your Acala wallet by following this guide.

You can learn how to create a MetaMask wallet by following this guide.

Address Binding

Note there are a few restrictions of the bind feature by design:

• Binds can only be done between one Substrate and one MetaMask account

• Neither account can be previously bound to another account. Additionally, binding is final - there is no unbind feature.

1) Go to Bind MetaMask in the Acala app. Click Connect to MetaMask and select the account you'd like to connect. Do the same thing for your Substrate account.

2) Double check that you are binding the correct accounts because this action cannot be undone. Click Sign.

If you are having trouble connecting your MetMask, you can either add it via Acala and Karura on ChainList, or manually add the Acala network by opening your MetaMask wallet and going to Settings-> Networks -> Add Networks and entering the following information: Network Name: Acala

New RPC URLhttps://eth-rpc-acala.aca-api.network/

Chain ID: 787

Currency Symbol: ACA

Block Explorer URLhttps://blockscout.acala.network/

3) Click Bind. Remember that in order to bind, you must have ACA in your Substrate account. You can learn how to send ACA to your Acala wallet by following this guide.

4) You should now see that your accounts have been successfully bound!

FAQ

Can I unbind and bind to a new account?

No. Once you bind two accounts together, you cannot unbind them. If you you'd like to use a different Polkadot account or a different Ethereum account, you'll need to create two new wallets.

Do I need to keep both seed phrases?

Yes. Please keep both seed phrases. If you ever need to recover all of your funds, you will need both sets of seed phrases.

Where can I see the MetaMask address linked to my account?

If you've already completed the binding process, click on your account in the upper right hand corner and then hover over the chain icon to see the linked MetaMask address.

What are the differences between auto-generated EVM address and binding my own EVM address?

There is no difference when you are using it within Acala/Karura, but binding your own EVM address gives you additional flexibility in interacting with your account using your EVM wallet such as MetaMask.

Why is MetaMask having trouble connecting to Acala?

If you are having trouble connecting your MetMask, you can manually add the Acala network by opening your MetaMask wallet and going to Settings-> Networks -> Add Networks and entering the following information: Network Name: Acala

New RPC URLhttps://eth-rpc-acala.aca-api.network/

Chain ID: 787

Currency symbol: ACA

Block Explorer URLhttps://blockscout.acala.network/