Verity is currently under active development and has not been released yet. Stay tuned for updates.
Ethereum Lean Consensus Client

Consensus You Can Mathematically Trust

Verity is the formally verified Ethereum consensus client. Core consensus logic is proven correct in Lean 4 and integrated into a Rust client via FFI — eliminating entire classes of bugs before they happen.

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theorem state_transition_correct : ∀ s b, verify (transition s b) = true

Security Through
Mathematical Proof

Where other clients test for correctness, Verity proves it. Formal verification closes the gap between specification and implementation — permanently.

Formally Verified

Core consensus logic is expressed and proven in Lean 4, then called from Rust via FFI. The verified code runs directly — there is no gap between what the spec says and what the code does.

Spec-Implementation Alignment

Traditional clients reimplement specifications by hand, introducing subtle divergences. Verity's approach makes such drift structurally impossible.

Eliminating Bug Classes

Formal verification doesn't just find bugs — it proves their absence. Entire categories of consensus-breaking errors are ruled out at compile time.

Lean Consensus Ready

Purpose-built for Ethereum's Lean Consensus roadmap. Verity's architecture is designed from the ground up to align with the protocol's evolving future.

Transparent Assurance

Every proof is open source and machine-checkable. Anyone can independently verify that Verity's implementation matches the Ethereum specification.

Client Diversity

A verified client adds a qualitatively different kind of diversity to the Ethereum ecosystem — one backed by mathematical certainty rather than independent reimplementation.

A Different Pipeline

Traditional clients translate specs by hand. Verity proves them mathematically.

Traditional Client

Read Specification

Human interprets the spec document

Manual Implementation

Re-write logic in Rust, Go, etc.

Test & Hope

Unit tests, fuzz tests, audits

Spec–implementation gap remains. Edge cases may hide undetected until production.

Verity

Encode Specification in Lean 4

Spec becomes machine-checkable types

Prove Correctness

Lean 4 type checker verifies every path

Call from Rust via FFI

Rust client invokes proven Lean 4 core logic

Core consensus logic is mathematically verified in Lean 4 and called from Rust via FFI — no re-implementation, no divergence.

Development Progress

Our path toward a formally verified, production-ready consensus client.

2026 — Building
Core State Transition Proofs & Devnet Participation
Proving correctness of 3SF consensus, PQ signature verification, and attestation logic. Joining Lean Consensus devnets alongside Ream, Zeam, Qlean, and other client teams.
2027 — Testing
Verified Client Alpha
First runnable client with verified core components — syncing and following the beacon chain on testnets. Public alpha for community testing and feedback.
2028+
Mainnet-Ready Stable Release
Production-ready client with comprehensive formal verification, performance optimization, and full Lean Consensus protocol compliance.

Nyx Foundation

Nyx Foundation is dedicated to advancing the security and reliability of decentralized infrastructure. We believe that critical protocol software deserves the highest standard of assurance — not just testing, but proof.

Verity is our flagship project: an Ethereum consensus client where correctness is not an aspiration but a theorem. By leveraging formal methods, we aim to set a new standard for what it means to trust blockchain infrastructure.

Lean 4
Language
100%
Open Source
0
Spec-Impl Gap
Test Coverage*

Build Consensus on Certainty

Explore the code, read the proofs, or join the conversation.