Jev in production › Code and security review

five-lines

Rust CLI that reviews a PR diff against the ten Five Lines of Code refactoring rules: tree-sitter counts the mechanical rules and Jev answers yes/no questions per changed method for the rest. Its second eval run scored 34 of 34 labelled judgments (author).

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34 of 34measured, as published by the source
Use
Code and security review
Industry
Developer tools
Form
Open-source tool
Stage
In production
Listed
2026-09-21
Found via
discord
Repository
jamescazzetta/five-lines
Stars
2
Forks
0
Last push
2026-09-20
Language
Rust
License
MIT

The README opens with

Use Jev to review a pull-request diff against the ten refactoring rules of Christian Clausen's Five Lines of Code (Manning). One binary, no runtime to install, for Windows, macOS and Linux. Ten languages are parsed exactly; any other is reviewed through Jev.

Jev is a model that returns a probability for a structured question instead of text. That fits code review well: each judgment becomes one atomic yes/no question ("does the condition of any if in this method have a side effect?"), the answers are combined in code, and the probability decides what gets raised and what is only "worth a look".

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For the project's own README, linking back here:

Listed in Jev in production

Also used for code and security review