{
  "slug": "zklean",
  "name": "zkLean",
  "tagline": "Galois's Lean 4 framework for R1CS and lookup-based circuits, Jolt-style",
  "maintainer": "Galois",
  "url": "https://github.com/GaloisInc/zk-lean",
  "repo": "https://github.com/GaloisInc/zk-lean",
  "category": "zk-circuits",
  "targets": [
    "R1CS",
    "Lookups",
    "MLE lookups",
    "RAM (Jolt-style)"
  ],
  "approach": "Lean 4, Hoare-triple style via Std.Do; soundness of extracted circuits",
  "license": "Open source (BSD-3)",
  "status": "Active, Ethereum Foundation funded",
  "summary": "zkLean is Galois's Lean 4 framework for stating and proving soundness of extracted circuits, with native support for R1CS, lookups, multilinear-extension lookups and RAM in the style of the Jolt zkVM. It ships a SHA-3 example and a Jolt extractor, and is one of the proof backends LLZK lowers to.",
  "details": [
    "Where Clean asks you to write the circuit in Lean, zkLean is designed around extraction: constraints are pulled out of an existing implementation (the Jolt extractor is the reference) and proved sound in a Hoare-logic style built on Lean's Std.Do monadic reasoning library. That makes it a natural fit for lookup-heavy designs where the 'circuit' is mostly table lookups and memory checking.",
    "Galois pairs zkLean with its Cryptol/SAW lineage and with LLZK, so Circom and Halo2 frontends can reach it through the shared IR."
  ],
  "strengths": [
    "First-class lookups, MLE lookups and RAM, matching Jolt-era zkVM designs.",
    "Extraction-oriented, so existing code can be verified without rewriting.",
    "Maintained by a firm with two decades of verification delivery."
  ],
  "limits": [
    "Primarily soundness; check the completeness story per project.",
    "Younger than Clean on published verified gadgets.",
    "Hoare-style proofs require familiarity with Std.Do."
  ],
  "fit": [
    "Choose zkLean for Jolt-style or lookup-centric systems, or when Galois is your verification partner and you want their Cryptol/SAW and zkLean work in one engagement."
  ],
  "references": [
    [
      "zk-lean repository",
      "https://github.com/GaloisInc/zk-lean"
    ],
    [
      "zkSecurity comparison including zk-lean (2025-11-19)",
      "https://blog.zksecurity.xyz/posts/formal-verification-arithmetic-circuits/"
    ]
  ],
  "category_name": "ZK circuit verification",
  "page": "https://sorryfree.com/frameworks/zklean/",
  "updated": "2026-09-13"
}