What it is
Create an API key at console.typesafe.ai and set it as PERCHAPIKEY.
The homepage listed on the repository, perchscan.com, puts it like this: Perch is an open-source semantic linter powered by SystemOne decision models. It reviews every pull request for bugs, security issues, and your own rules, for about 20¢ a pull request.
Getting started
From the README:
npm install -g @lakeday/perch
perch login
perch scanWhere the decision sits
perch calls the hosted decision API rather than running its own weights. That keeps the project small and means its behaviour moves whenever the vendor ships a new model version. It also means an API key and a network round trip sit in the path of every decision.
Models it references: Jev.
How active it is
Created 2026-09-16, last pushed 2026-10-30, 358 stars and 22 forks when we read it on 2026-11-02. Everything in this category is weeks old at most, so a stale push date means something different here than it would on a mature project. Check the repository before you depend on it.
Find out what your data actually supports
We turn your historical decisions into a frozen test set, then tell you which model, which threshold, and how much of it you can safely automate.