A custom cop collection of working toolkits.

Pure-Ruby MIDI library for messages, ports, SMF I/O, middleware, network MIDI, and MIDI 2.0 UMP.

Catch Active Record transactions napping—detect non-database idle gaps while locks may be held.

A three.js-like scene graph and WebGPU renderer for Ruby, with PBR, glTF, animation, shadows, and offscreen rendering.

A slim file to minify embedded code.

Battery-included monitoring and alerting for Sidekiq

Japanese seasonal and lunisolar calendar calculations in Ruby: 24 solar terms, 72 microseasons, observances, new moons, and date conversion.

Pure Ruby bindings for Linux seccomp user notifications

A RuboCop Extension Template.

rspec-rewind is a modern retry orchestration gem for RSpec.

RSpec coverage intent metadata, strict coverage checks, and traceability suggestions.

Ruby JSON processor with a practical jq 1.7.1-compatible subset, CLI, and Ruby API.

Rdeck is a Ruby CLI tool that converts Markdown presentations to Google Slides, enabling continuous deck creation with content and design separation.

Educational compiler backend targeting C through printf %n, with Brainfuck and conservative LLVM IR subset frontends.

A small Mackerel metrics client for PicoRuby that validates service or host metric batches before a single verified HTTPS POST.

Simple YAML Frontmatter Parser

Hybrid dead-code detection for Ruby projects.

Ruby bindings for Linux's file-descriptor-based mount API

A fast, Prism-native Ruby linter

Generate Mermaid diagrams from Rails models and controllers.

Research-backed safe regression test selection and fast test feedback for Ruby.

Ruby bindings for Jolt Physics, powered by joltc, FFI, and larb

A hobby regex engine written in Ruby. Designed to be simple and efficient for educational purposes.

A differentiable 3D Gaussian splatting renderer and trainer for Ruby, with Numo::NArray and optional OpenMP acceleration.

A tiny Ruby library for generating finite state machine (automaton) diagrams as SVG.

OpenTelemetry browser and SSR adapters for Funicular, with OTLP and W3C Trace Context support.

A small Ruby gem for reading large JSON array, NDJSON, and CSV inputs one record at a time

A Ruby audio synthesis library with a flexible node graph, oscillator and synth variants, effects, transport/event scheduling, sample playback, analysis utilities, offline rendering, and an optional PortAudio-backed realtime context.

Language Server Protocol (LSP) implementation for Lrama Style BNF grammar files (.y files).

Lightweight Ruby toolkit for building small music scores, parsing a LilyPond-style syntax subset, and exporting PDF, SVG, or MIDI.

Capture legacy Ruby behavior, synthesize portable specifications, and verify replacement implementations with replay and bounded formal checks.

Web Bluetooth API-style BLE interface for Ruby.

Ruby bindings for WebGPU via wgpu-native.

A pure Ruby audio processing gem focused on ergonomic APIs and immutable audio transforms.

Texture-oriented image decoding, conversion, resizing, and GPU upload helpers for Ruby.

Ruby bindings for the Skia 2D graphics library.

Generate beautiful terminal screenshots from YAML.

化学式を解剖し、分子の量を秤り、反応式を釣合はすRubyGemに候

象算木之法，以字畫示整數加減之程

A RuboCop extension focused on enforcing committee.

Detect RSpec examples that leak global state, resources, time travel, randomness, or filesystem changes.

Detect ignored ActiveRecord rollbacks in joined nested transactions

Dependency-free Ruby library for loading and writing glTF 2.0 and GLB with GPU-ready packed accessors.

🛤️ A tiny Ruby+SVG library for drawing railroad syntax diagrams like JSON.org.

Detect PostgreSQL and MySQL session-state leaks in Active Record connection pools.

A practical Perl 5 interpreter written in pure Ruby

Pure Ruby library and CLI for reading, composing, editing, and writing OpenUSD USDA and USDZ assets.

A visual editor for Lrama grammar files (.y files) powered by Ruby Wasm.

Pure Ruby JPEG XL decoder and lossless Modular encoder with no native extensions.

Generated Ruby bindings for Dear ImGui with an idiomatic API, exception-safe DSL, GLFW/SDL3/OpenGL/WebGPU backends, and ImPlot.

Ruby bindings for HarfBuzz text shaping engine

A Prism-based codemod for safely migrating deprecated graphql-ruby APIs without booting the application.

A cli that highlights gems you can likely remove from a Ruby project's Gemfile.

Ruby FFI bindings for FreeType 2.11+, with SDF atlases and HarfBuzz text meshes.

Ruby bindings for Linux fanotify

A Ruby live coding toolkit for composing musical patterns with rational time and OSC/MIDI output.

A linter and formatter for Lrama-style BNF grammar files.

Auto-fix N+1 queries detected by Bullet at runtime.

Idiomatic, memory-safe Ruby bindings for Box2D v3

Fast Prism-native AST traversal, declarative matching, and source rewriting for Ruby

WebXR Device API bindings for Ruby. Build VR/AR applications in Ruby using ruby.wasm.

Building audio-reactive visuals with a Ruby DSL.

Report and block unintended syscalls in Ruby builds and tests

RuboCop runner for Ruby code embedded in Slim.

Evidence-based test suite adequacy analysis for Ruby, combining coverage, mutation testing, checked coverage, redundancy detection, and test-smell heuristics.

Fast JSON Schema validator for Ruby.

Native CRuby bindings for libseccomp with low-level and Ruby-friendly APIs.

A RuboCop extension focused on enforcing RSpec. A place where no one is officially employed, but where useful cops can gather.

Runtime risky-test detection for RSpec: reports tests with no expectations or unexpected output.

Detect, record, and classify flaky RSpec failures with normalized signatures, isolated reruns, and CI-friendly reports.

Catch Active Record objects whose database writes rolled back while their in-memory state stayed changed.

Ruby bindings for RenderDoc's in-application API, with programmatic GPU frame capture and RSpec integration.

Pure Ruby interface to Linux Pressure Stall Information (PSI)

Decode PicoRuby/R2P2 Cortex-M HardFault logs with matching ELF debug symbols

Parselly is a module providing a simple way to parse and extract data from a css selector 🌿

A modern, dependency-free Ruby client for the Notion API

A Ruby audio feature extraction library that provides a full pipeline from audio loading to spectral analysis, feature extraction, rhythm analysis, effects, and lightweight visualization.

A Pure Ruby Markdown linter and formatter.

Frame-level Ruby bindings for FFmpeg video and audio encoding/decoding without subprocesses.

A terminal slide rule simulator for Ruby, with interactive sandbox, demo, and drill modes.

Strict JSON5 1.0.0 parser in Pure Ruby with generated grammar, diagnostics, limits, and lossless Document mode.

Pure Ruby LR parser generator with racc-compatible grammars, EBNF extensions, diagnostics, and SLR/LALR/LR(1) backends.

落語調の帳場言葉で書く、小さな算譜言語「噺椎」の Ruby 処理系。

Check GraphQL-Ruby resolver contracts against Prism-parsed Ruby source before runtime.

Bounded, browser-local profiler for Funicular and PicoRuby development tooling.

Ruby-native lexer generator for parser authors. Write ordinary Ruby specs, run them at runtime, or generate deterministic Ruby for deployment.

Share FactoryBot data safely across RSpec examples

Causal profiling toolkit for Ruby that estimates which lines or waits would actually improve throughput or latency.

Ruby FFI bindings for robust Clipper2 polygon clipping, offsets, and GPU-ready triangulation.

Deterministic syscall fault injection for Ruby programs using Linux seccomp user notifications.

Observe file, network, and process capabilities used while installing or requiring Ruby gems.

Ruby bindings for the Assimp 5.x asset import library