Mike OSS Offers Free Alternative to $11B Legal AI Giant

A former Latham & Watkins associate has launched Mike, a free, open-source legal AI tool that matches proprietary platforms valued in the billions.

William Chen built and released Mike in May 2026, offering law firms and legal teams a free alternative to enterprise legal AI platforms Harvey and Legora. Chen developed the full web application in two weeks and published the code publicly on GitHub, allowing anyone to download, run, and customise the tool.

This launch matters because it directly pressures the legal AI market, where leading platforms carry valuations of billions of dollars, by offering comparable functionality at no cost.

What Mike Does

Mike is an AI assistant that can create, edit, and review legal documents. It supports file storage through a project’s vault, enables bulk document review through tabular review, and includes customisable workflows for setting instructions or review presets.

The tool runs on either Claude or Gemini as its underlying AI model. Law firms can choose to run Mike locally on their own systems, meaning files and data never leave their internal environment.