Halmos

Open Source

Halmos is a symbolic testing tool for EVM smart contracts, with a Solidity and Foundry frontend. Run halmos in a Foundry project when you want existing tests explored symbolically.

About

The a16z/halmos README describes a symbolic testing tool for EVM contracts. The halmos command is the Solidity and Foundry frontend. The README recommends installing with uv and calls pip not recommended. Activity has slowed: the last commit is from 2025-08-06 and the last release, v0.3.3, from 2025-07-31.

Categories

Formal Verification Testing

Chains

ethereum polygon arbitrum optimism base

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Install

uv tool install --python 3.12 halmos

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Quick Info

Pricing
free
Open Source
Yes
Last validated
Oct 2026

Links

Website GitHub Documentation