Verity

The Provable Consensus Client — a formally verified @leanEthereum
client built with @leanprover

[Verity @verityclient]

@tcoratger We'll keep bringing the safety of formal verification to Ethereum.

https://t.co/x5qEqxwfei

[Verity @verityclient]

While formalizing the @leanEthereum spec in @leanprover, we found several critical bugs hiding in the spec itself.

Here's what we found 🧵

https://t.co/F2eAD9quvC

[Verity @verityclient]

@tcoratger Closing

Formal verification prevented many problems before they could do harm. These were serious issues that had gone unnoticed until now — and testing had missed every one of them.

[Verity @verityclient]

You can check our talk from here !

https://t.co/xcJQMhwRjy

[Verity @verityclient]

From our team, @adust09 will give a talk on the use of formal verification in client development at @eth_proofs call #9🏌

[Verity @verityclient]

From our team, @adust09 will give a talk on the use of formal verification in client development at @eth_proofs call #9🏌

[Verity @verityclient]

From our team, @adust09 will give a talk on the use of formal verification in client development at @eth_proofs call #9🏌

[Verity @verityclient]

Verity is a "Lean" consensus client designed with formal verification in mind.

@VitalikButerin explains why formal verification is important for Ethereum.

must-read👀

[vitalik.eth @VitalikButerin]

Many people have claimed that with AI-assisted bug finding, secure code (and hence trustless anything) will be impossible.

I have a much more optimistic take, and AI-assisted formal verification is a major part of the reason why:

https://t.co/0ceMBZ6uqj

[Verity @verityclient]

leanSpec Weekly Report (May 9 – May 16, 2026)

https://t.co/daqrcA8nQj

[Verity @verityclient]

strawmap has been updated!!

←before
after

Decoupled Consensus, set to debut in 2027, will refine existing consensus layer.

This will enable fast finality, eliminate vulnerabilities, and accelerate the transition to PQC.

https://t.co/XSX0tSTZP6

[Verity @verityclient]

https://t.co/Y4KGOCy17L

[vitalik.eth @VitalikButerin]

This theorem (left) means, the only way you can make proofs for two different things in the same position in the same Merkle tree, is by breaking the underlying hash function.

As a reviewer, you don't have to verify how Merkle branches are implemented or how the theorem is proven (right), you just have to verify what the theorem says, and that Lean verifies it.

And the beautiful thing is that you can even write live production code (including eg. CLI tools) directly in Lean.

[Verity @verityclient]

leanSpec Weekly Report 📒
(Apr 25 – May 2, 2026)

https://t.co/jHxfz2gTH6

[Nyx Foundation @NyxFoundation]

VerityのWebサイトが完成しました！

Ethereumの最もセキュアなLean Consensusクライアントを目指します。