Request for Comments: Aztec Sequencer Selection and Prover Coordination Protocols

Today, Aztec Labs is excited to share the winning proposal from the prover coordination protocol request for proposals (RFPs) – “Sidecar”. Additionally, we are announcing a formal request for comments period covering Aztec’s Sequencer Selection and Prover Coordination Protocols, key components of Aztec’s block production.

At the heart of Sidecar’s design is the decision to facilitate proving outside of the scope of the protocol, enabling integrations with various solutions, such as decentralized zero-knowledge proving marketplaces. Read the latest documentation on Aztec’s block production.


Why Sidecar?

The Aztec Labs team, with input from various industry-leading experts, chose Sidecar over the various other proposals submitted (1, 2, 3, 4, 5, 6) due to its simplicity and ease of integration – very similar to the reasons the Fernet Sequencer Selection protocol was chosen during a previous RFP process.

Further, the decision to not enshrine a particular prover coordination protocol enables Aztec Labs to continue iterating on proving networks or marketplaces outside of the scope of the Aztec network’s traditional upgrade mechanisms – similar in spirit to Vitalik’s notion of “minimum viable enshrinement“.

Additionally, not enshrining a particular protocol in this way allows the network to be fully compatible with a broad spectrum of options to prove a given block, including:

  • vertical Sequencer-Prover integration, or
  • third party zero-knowledge (zk) proving providers, or
  • fully decentralized zk proving marketplaces

Through these various options, Aztec’s proving is fully permissionless and allows anyone to participate in a competitive marketplace for zero knowledge proof production.

“We are excited to collaborate with other projects that share our vision for decentralized zero-knowledge proving. If you are interested in partnering with us to build a better, privacy-enabled future, please reach out via email at”

Leave comments on Aztec’s Sequencer Selection and Prover Coordination Protocols

If you have feedback, suggestions, and/or potential improvements, please leave a message on the Discourse post linked below, or reach out to Bruno Lulinski at We would greatly appreciate comments being left prior to Friday, February 16th.



The Aztec Labs team is very grateful and appreciative of those who contributed prover coordination protocol proposals, including: 

  • Santiago @ Aztec Labs
  • Phil @ Aztec Labs
  • Cooper @ Aztec Labs
  • Joe @ Aztec Labs
  • Ellie @ Espresso Systems
  • Norbert, Nilu, Rachit @ EF Research
  • Pintea Tudor 
  • Anon on the Aztec Research Forum

We would also like to thank those whose conversations contributed to the review and decision-making process, helping us build towards a more decentralized future for zk: 

  • Yuki @ Fenbushi Capital 
  • o1Labs
  • Toghrul @ Scroll 
  • Figment Inc. 
  • Misha @ Nil
  • Teemu @ Gevulot

Keep in touch

To learn more about Aztec generally, keep up to date on our Discourse, where we discuss major protocol decisions like upgrade mechanisms and decentralizing sequencers.

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