Layer 2 FAQ

Answers to all your lingering L2 questions.

March 1, 2022

The launch of our Layer 2 was met with a lot of excitement and a few questions. Don’t fret, we have answers. Below is a selection of the most frequently asked questions and our responses.

If you're still stumped, head to ~bitbet-bolbel/urbit-community or give us a shout online.


Planet Booting, Buying, Custody

  1. Do I need ETH to boot my planet?
  2. Do I have full custody of my L2 planet?
  3. Where can I buy a planet?
  4. How do I get a hosted planet?

Layer 2 Architecture & Migration

  1. Why did you decide to build your own Layer 2 rollup?
  2. Should I migrate my L1 planet to L2?
  3. Where did the old Bridge go? Can I still use it?
  4. Why is the cost reduction so significant?
  5. What exactly is the mechanism for the “naive” consensus?
  6. When I spawn L2 planets via Metamask, I'm prompted to sign every transaction. Do you have plans to remedy this?

1. Do I need ETH to boot my planet?

If you were invited to claim a L2 planet, you do not need ETH to claim that Urbit ID. Anyone can get on Urbit without ETH or a crypto wallet via L2. Inviting your mom to Urbit just got a lot easier.

If you have a L1 planet, you do need ETH to claim that Urbit ID.

Once you have claimed your Urbit ID and have recorded your master ticket, you do not need ETH to boot Urbit. That Urbit ID is now yours, forever.

Unsure whether you have been invited to claim a L2 or L1 planet? The quickest way to identify a L2 planet is if you used the below flow to claim.

For those with L1 planets, you can avoid future transaction fees by migrating your L1 planet to L2. Read the migration instructions here.

2. Is there anything I need to do to ensure full custody of my planet?

If you were sent a direct link to claim an L2 planet (see above), it’s in your full custody by design. Bridge generates your master ticket, which you downloaded during the claiming process.

3. Are there any platforms where I can buy a planet for BTC or USD?

There are a few ways to procure a planet, including some platforms that offer BTC and USD payment options.

To purchase a L2 planet, we direct you to:

To purchase a L1 planet with ETH, there are a number of platforms dedicated exclusively to Urbit ID. These include:

You can also acquire L1 Urbit IDs with ETH on OpenSea.

Once you purchase a planet, the easiest way to manage your cryptographic asset is through Bridge, which is our Urbit ID management interface, wallet navigator, and governance portal.

You can use Bridge to perform any desired Azimuth interactions or download your planet’s keyfile. As an alternative, Metamask is an easy-to-use Ethereum wallet with a browser extension that integrates easily with Bridge.

4. How do I get a cloud-hosted planet?

There are a number of ways to host a planet in the cloud. Your options:

5. There are plenty of organizations dedicated to customizable rollup solutions. Why did you decide to build your own?

Simply put, we designed and engineered our own rollup because we can’t depend on the success or longevity of another organization. As they currently exist, outsourced rollups are too immature and compromised in ways that undermine the integrity of our technical principles. We also can’t restrict the aggregators to a waitlist, another issue which might eventually be resolved, but one that we can’t count on to be resolved soon.

6. If I currently have an L1 planet, are there any advantages to migrating?

One of the most significant advantages to migrating is the reduced cost of Azimuth-event related transactions. On L2, you can change sponsors or reset your network keys for free with our roller. An important note: migration is currently one-way. If you want to hold onto your L1 planet as a novelty, migration isn't recommended.

7. Is it possible to use the old Bridge for L1 operations?

The old version of Bridge will remain live, but unmaintained and eventually decommissioned. You can access it at If you run into something you can only do with the older version of Bridge, let us know on Github.

8. Why is the cost reduction so significant?

On L1, every operation is an Ethereum transaction, with logic and state, etc. On L2, these operations are reduced and simplified into a no-logic-involved Ethereum transaction. This is what makes L2 transactions cost-efficient: multiple transactions happen simultaneously to share the cost of just one L1 transaction.

9. What exactly is the mechanism for the “naive” consensus?

Our engineering team has written extensively about the technical features of our L2 rollup. To learn about its intricacies, we encourage you to read ~datnut-pollen’s comprehensive overview and ~wicdev-wisryt’s original proposal on the Urbit developer mailing list.

10. When I spawn L2 planets via Metamask, I'm prompted to sign every transaction. Do you have plans to remedy this?

We realize this UX headache and are taking active steps to devise a more efficient transaction scheme. The new method will reduce the number of manual signatures needed for each spawned L2 planet. At the time of this FAQ's publication, we haven't publicized the release timing for the improvement. A provisional solution: set the star's spawn proxy to a custodied L2 planet secured via Master ticket and log in to Bridge as that planet to spawn invites.