Frequently asked questions

The Rainbow Bridge 2.0 is the new offical bridge for transferring tokens between Ethereum, NEAR and the Aurora networks.

If you had pending transactions on the old bridge, just connect your wallet, click the the “Scan transfer history” button, and after a few moments, those transactions will appear.

There are four types of transfers, each of which costs something different:

1. Transfers between NEAR and Aurora require a single transaction, cost a few cents and happen instantaneously.
2. Transfers from Ethereum to NEAR or Aurora require a single transaction, and happen in about 20 minutes. The cost will be estimated in MetaMask prior to confirming the transaction.
3. Normal transfers to Ethereum from NEAR or Aurora involve two transactions. The finalization can take up to 8 hours, and its cost will depend on gas prices at that time, and are therefore unpredicable.
4. Fast transfer to Ethereum, which are currently in private testing, typically complete in 2-5 minutes, and require a fee displayed at time of transfer.

When transferring from Aurora or NEAR back to Ethereum, if Ethereum is congested and your finalization transaction is expensive, you can simply wait for Ethereum to become less congested and for gas prices to drop. You do not have to immediately finalize the transfer! You can wait as long as you like, using a gas estimator extension in Chrome to watch for drops in gas prices.

Your transaction history is stored in the local cache of your browser. In case that storage would get lost, or you experience hiccups due to network interruption, this feature will rescan the blockchains, and rebuild your transaction history.

The original Rainbow Bridge 1.0 will remain available for some time, to access pending transactions, and advanced developer features—like new token deployment—until these features are added to this new Rainbow Bridge 2.0.

The original Aurora Bridge has been discontinued, since Rainbow Bridge 2.0 contains its full functionality. If you had pending transfers on the Aurora Bridge, you can recover them by connecting your wallet and using the “Scan transfer history” feature.

You can wrap and unwrap the NEAR token at Ref Finance.

You can raise a support ticket using the little green icon in the bottom right corner of the screen. We usually reply within 24 hours.

In case of emergency, you can try to reach us on Discord, or interact with our increasingly-smart support bot on Telegram.

If you are a developer, and you can deploy tokens using the Rainbow Bridge:

• Ethereum ERC-20 tokens can be deployed to NEAR and Aurora.
• NEAR NEP-141 tokens can be deployed to Aurora.

Following is the process:

1. Access the Rainbow Bridge deployment feature.
2. The UI will walk you through the deployment steps.
3. Once deployed, raise a pull request on this repository to have the Aurora team add your metadata.
4. Once the Aurora team process and approve your PR, your token will be searchable by symbol on the bridge transfer form and other dApps will be able to display balances correctly.

For questions, you can reach the bridge team at bridge@aurora.dev.