Strict Ivars is a tiny pre-processor that guards you against undefined instance variable reads. If you do read an undefined instance variable, it will raise a NameError.

convert ruby code to better syntax automatically.

Configurability is a unified, non-intrusive, assume-nothing configuration system for Ruby. It lets you keep the configuration for multiple objects in a single config file, load the file when it’s convenient for you, and distribute the configuration when you’re ready, sending it everywhere it needs to go with a single action.

Code analysis for documentation generation.

Auto-generate inline YARD documentation for Ruby by analyzing code AST. Supports RBS and Sorbet type signatures.

Based on, concerned with, or verifiable by observation or experience rather than theory or pure logic.

Ivar is a Ruby gem that automatically checks for typos in instance variables.

A tiny pre-processor for ruby that adds runtime type checking to methods.

A minifier of Ruby files.

Runs (Get it? It's fast!) your tests and makes it easier to rerun individual failures.

A prism parser backend

RBS::Trace collects argument types and return value types using TracePoint, and inserts inline RBS type declarations into files.

Ruby code rewriter.

Rigor is a CLI-first static analyzer for Ruby applications that prioritizes type inference, clean application code, and zero runtime dependencies. Rigor is a standalone tool, not a library: install it independently rather than adding it to your application's Gemfile. It runs on Ruby 4.0 while your project keeps its own Ruby, and it reads your project as data rather than loading it, so a Gemfile entry only constrains your application's Ruby and dependency resolution. Installation channels (mise, asdf, gem install, container, Nix): https://github.com/rigortype/rigor/blob/master/docs/install.md

Sirop: Ruby code rewriter

Rails static code analyzer for security issues

A simple test framework for Ruby code where the test descriptions and expectations are written as comments.

Mutation testing for Ruby and Rails. Uses Prism-based source-span mutations (no unparser), coverage-mapped test selection, and a fork-per-mutant kill pipeline. Scopes to changed methods for a fast dev loop, or to a diff for CI. Includes an incremental coverage baseline and a committed acceptance ledger for equivalent mutants.

Inspect, parse, and visualize the callbacks registered on your ActiveRecord models — including their if/unless conditions — as graphs and diagrams.

A static architecture linter for Ruby and Rails. Declare your components, dependencies, and boundaries in one file, then check every change in CI. It reads source with Prism and never boots the app.