Frequently asked questions

What is this?

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

Where are my pending transactions?

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.

How much does this cost?

Transfers between NEAR and Aurora require a single transaction, cost a few cents and happen instantaneously.

Transfers from Ethereum require a single transaction, and happen in about 10 minutes. The cost will be estimated in MetaMask prior to confirming the transaction.

Transfers to Ethereum, however, involve two transactions—the kick-off on Aurora or NEAR, and the finalization on Ethereum. The finalization can take up to 16 hours, and its cost will depend on gas prices at that time, and are therefore unpredicable. We have seen them as high as $300 when Ethereum is very congested!

And once started, transactions can not be cancelled—so keep all this in mind when making small value transfers!

What can I do if the finalization transaction is too expensive?

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.

What is the “scan transaction history” for?

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.

What happened to the original bridges?

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.

How to unwrap NEAR?

You can wrap and unwrap the NEAR token at Pulse Market. Click the three-dot menu in the upper right.

Where can I get help?

You can raise a support ticket using the little black 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.

I'm a developer and want to add my token

Soon, you will be able to bridge your token and metadata directly to Aurora and NEAR using the UI of Rainbow Bridge 2.0. Until then, here is the process:

  1. Use version 1.0 (NEAR or Aurora) of the Rainbow Bridge to bridge your token to NEAR or Aurora. 
  2. Raise a pull request on this repository, to have the Aurora team add your metadata.
  3. Once the Aurora team process and approve your PR, your coin will receive one of two categorizations — "whitelisted", in which case it will automatically appear on the Rainbow Bridge 2.0, or "authorized", in which case it will be supported by the bridge, but users will need to paste in your token's source contract address. For questions, you can reach the bridge team at bridge@aurora.dev.