New Görli testnet and getting Rinkeby ready for Nitro

tl;dr — Our new Görli testnet for Arbitrum Rollup is now live, and we’ll be migrating our Rinkeby testnet to Nitro this month. Take time to make preparations, and get ready for Nitro! View the Nitro Migration notes here. See the new testnet info in our docs!

Developers! Builders! Hardhatspeople? A new testnet has been spotted!

Fellow Arbinauts, back in April we launched our Nitro devnet built on Görli and shared more of our plans to migrate our Arbitrum Rinkeby testnet to the Nitro stack. Well, the day of testnet evolution is upon us and we now have a new Arbitrum Rollup Görli testnet, with plans to upgrade our Arbitrum Rinkeby testnet later this month. When this happens it will mean that all Arbitrum Rollup testnets will be running on Nitro, leaving us with only one major step left in our overall upgrade to Nitro — the Arbitrum One migration!

And now a word for developers. If you haven’t already begun, now is the time to start really preparing for Nitro. As we’ve mentioned before Nitro is bringing many changes — calldata compression, Eth L1 gas compatibility, safer retryables, and so many more! For projects on Arbitrum One, these changes can affect smart contract functionality, and will require proper configuration to ensure your dapps continue to work seamlessly once Arbitrum One migrates to Nitro. Take time to make necessary changes and battle test your code before the mainnet migration happens. Luckily as we just mentioned, we’ve got a new testnet for that, and a planned migration of Arbitrum Rinkeby down the line. For developers who are just getting started preparing for Nitro, we have an overview of what’s coming, including any breaking changes — it’s worth a read.

Launching a new Arbitrum Rollup Görli Testnet

At the time of this post our new Arbitrum Rollup Görli testnet is live, which means you can start interacting with the chain as you would on Ethereum and in a similar fashion to the previous testnet. We’re being explicit about using the word “Rollup” here because this testnet, like the devnet before it, is using Arbitrum Rollup technology, not AnyTrust.

There are a few considerations to keep in mind, this testnet is built on Görli rather than Rinkeby, and has a new ChainID of 421613 and RPC URL at https://goerli-rollup.arbitrum.io/rpc. Once you’re settled and connect your wallet to the new Görli testnet you can visit our bridge to begin bridging assets over. You can also request funds from the faucet by sending out this tweet.

Most importantly, this is a new testnet with an entirely new chain state, and this will replace our existing Görli devnet — which we plan to spin down in about a week’s time, on July 22nd around 12:00 PM ET. If you want to withdraw assets from the existing Görli devnet, now is the time to do so. For all of the specifics on the new testnet, you can view our documentation.

Another important callout here is that we are launching this testnet to be the long-term testnet for Arbitrum Rollup. Görli is one of the two major Ethereum testnets with plans to be supported well into the future and we want developers to have confidence that the testnet they are building on will operate for the foreseeable future. This is a massive step forward, and brings us much closer to migrating Arbitrum One to Nitro. The work leading up to this point has been monumental, not only because of the incredible innovation involved with building Nitro, but also because of our intent to build a sustainable rollup stack that we will continue to maintain for years to come.

Moving Arbitrum Rollup Rinkeby to Nitro

The other piece of news today is our timeline for upgrading our existing Arbitrum Rollup Rinkeby testnet to the Nitro stack. In April we shared our plans for the Arbitrum One migration to Nitro, and marked the Rinkeby migration as the second key step in doing so. We want to make sure developers can fully prepare for the mainnet migration, and our current plans are to carry out the Rinkeby migration later this month. As mentioned in our previous post this migration will maintain the state of all accounts and contracts, as we are aiming for it to be a seamless transition. You can view our Nitro migration notes here.

We do want to surface some recent information from the Ethereum Foundation regarding their plans to deprecate Rinkeby, alongside Ropsten and Kiln. Currently their plan is to deprecate Rinkeby around Q2/Q3 2023, and you can read more about those plans here. The takeaway is that as a result, the Arbitrum Rinkeby testnet will be spun down at some point. We are not in a rush to do so and very much plan on keeping it around well after the Arbitrum One migration to Nitro. That being said, the Rinkeby testnet will be deprecated eventually — the good news is that our new Arbitrum Görli testnet is live, so you might want to check that out, and pour one out for Rinkeby.

We will of course keep the developer community updated on our plans here as they progress. We continue to be focused on Nitro, and Rinkeby is very much a part of that transition.

One step closer to Nitro on Arbitrum One

Once the Rinkeby migration to Nitro is complete, we will have completed two of the three major milestones we originally laid out for Nitro migration on Arbitrum One mainnet. We know folks are ready and waiting for that to happen, and want to reiterate that part of ensuring the mainnet migration is as seamless as possible means ensuring we have ample time to test, fix any outlying bugs, and then prepare for the final migration. We know many teams are eager to take advantage of Nitro, and we want to make sure that the transition is smooth.

Oh right, we also launched Arbitrum Nova earlier this week, our first chain built on our AnyTrust technology. First of all, thank you to the teams who have already reached out to begin onboarding and if you’re reading this post and considering doing the same please fill out this form. You might be asking “how does this relate to the Arbitrum One migration to Nitro?” Well, Nova’s AnyTrust technology shares a codebase with Nitro, and AnyTrust is just enabled via a config switch. Deploying this new chain, built on Nitro, gives our team even more experience onboarding projects ahead of the mainnet migration of Arbitrum One.

So in summary, we’ve got a new Arbitrum Rollup testnet with plans to spin down the existing Nitro devnet. We’re also planning to carry out the Arbitrum Rinkeby migration to Nitro later this month. There’s a lot in the works and we couldn’t do it without consistent feedback from our developer community and the overall passion and enthusiasm we receive from Arbinauts worldwide. Thank you for joining us on this journey and we’ll be sharing more with you all very soon.