Prysmatic Labs
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Prysmatic Labs

Introducing the Onyx Testnet

This update was proudly written by the Prysmatic Labs team.

Several months ago, we successfully launched the Topaz testnet, the first public testnet with mainnet-scale parameters for eth2. Topaz had a great run, kicking off with a successful genesis launch event live streamed on youtube here. Now, we are taking our testnet to the next level and ramping it up to the latest official specification for eth2, the v0.12.1 release which is aimed to be the final, non-trivial spec update before mainnet for phase 0.

We are proud to announce our new and improved testnet for Ethereum 2.0 Phase 0: The Onyx Test Network. This testnet is targeting v0.12.1 of the official Ethereum 2.0 specification, which is aimed to be the final specification before a mainnet launch and multiclient ready.

The 5 Milestones for Prysmatic Labs’ Journey to Eth2 Mainnet

Topaz Testnet Recap

Topaz tesnet progressions

The previous testnet, Topaz, allowed validators to deposit the full 32 ETH on the Goerli ETH1 testnet to participate. The Topaz testnet, at the time of writing, has 39823 active validators, wit h less than 35% of the network controlled by the Prysmatic Labs team. The testnet has sustained a significant amount of decentralization of nodes, with some nodes reporting peer counts as high as 700. Despite its great numbers, the Topaz testnet was not multiclient compatible due to a consensus error that would prevent other client teams from successfully syncing the chain.

What’s New In Onyx

The next iteration of the Topaz, the Onyx testnet, is a new and improved release containing several important quality of life improvements, revamped p2p message handling, and alignment to the latest specification for Eth2.0. The v0.12.1 release of the official specs are the target for a mainnet release barring any significant errors, and Onyx is fully up to date with the spec. Among some of the high-level changes included in the testnet are:

  • Better handling of attestation subnets over p2p, improving the robustness of the networking implementation for eth2
  • Significantly improved testing around dangerous consensus code such as rewards/penalties calculations
  • Improved eth1 data handling
  • Ensure balances remain unchanged for optimal validators during inactivity leak, which will significantly improve user experience

The Onyx test network is now accepting genesis deposits. Soon, Prysmatic Labs will start turning down our Topaz validators and begin sending new genesis deposits. Onyx is a new blockchain with new validators, which will require you to go through the deposit process once again.

If you would like to be a genesis validator, send your deposit before 17:00 UTC Wednesday, June 10th, 2020 as that is when Prysmatic will begin sending deposits en masse to kick off the test network. Get started on the testnet onboarding site and join us on Discord!

We are aiming for the Onyx testnet to be multiclient compatible. We have put in extra work to prevent consensus bugs in this new release, and once other client teams are fully up to date with v0.12.1, we expect there will be significant number of nodes in the Onyx testnet from different eth2 teams.

REMINDER: Onyx is still a testnet using fake, test ETH. Never send any real ETH to the deposit contract!

Onyx Testnet Information

Deposit contract address:


Fun fact: this address has the same hex colors as the Onyx color #0F0F0F!

Configuration: Mainnet

Spec version: v0.12.1 (Latest release)

Prysm version: v1.0.0-alpha10

Testnet site:

Prysm API:

Requesting Goerli ETH Form

We have put together a form for requesting bulk amounts of Goerli ETH to join the testnet here. If you want to run a larger number of validators, please fill out the form!

System Requirements

Recommended Specifications:

Operating System: 64-bit Linux, Mac OS X, Windows, Arm64

Processor: Intel Core i7–4770 or AMD FX-8310 or better

Memory: 8GB RAM

Storage: 100GB available space SSD

Internet: Broadband connection

Minimum Requirements:

Operating System: 64-bit Linux, Mac OS X, Windows, Arm64

Processor: Intel Core i5–760 or AMD FX-8100 or better

Memory: 4GB RAM

Storage: 20GB available space SSD

Internet: Broadband connection

Interested in Contributing?

We are always looking for devs interested in helping us out. If you know Go or Solidity and want to contribute to the forefront of research on Ethereum, please drop us a line and we’d be more than happy to help onboard you :).

Check out our contributing guidelines and our open projects on Github. Each task and issue is grouped into the Phase 0 milestone along with a specific project it belongs to.

As always, follow us on Twitter or join our Discord server and let us know what you want to help with.

Official, Prysmatic Labs Ether Donation Address


Official, Prysmatic Labs ENS Name




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