== Terminal UIs, the Ruby Way RatatuiRuby[https://rubygems.org/gems/ratatui_ruby] is a RubyGem built on Ratatui[https://ratatui.rs], a leading TUI library written in Rust[https://rust-lang.org]. You get native performance with the joy of Ruby. gem install ratatui_ruby {rdoc-image:https://ratatui-ruby.dev/hero.gif}[https://www.ratatui-ruby.dev/docs/v0.10/examples/app_cli_rich_moments/README_md.html] === Rich Moments Add a spinner, a progress bar, or an inline menu to your CLI script. No full-screen takeover. Your terminal history stays intact. ==== Inline Viewports Standard TUIs erase themselves on exit. Your carefully formatted CLI output disappears. Users lose their scrollback. Inline viewports solve this. They occupy a fixed number of lines, render rich UI, then leave the output in place when done. Perfect for spinners, menus, progress indicators—any brief moment of richness. require "ratatui_ruby" RatatuiRuby.run(viewport: :inline, height: 1) do |tui| until connected? status = tui.paragraph(text: "\#{spin} Connecting...") tui.draw { |frame| frame.render_widget(status, frame.area) } end end === Build Something Real Full-screen applications with {keyboard and mouse input}[https://www.ratatui-ruby.dev/docs/v0.10/examples/app_all_events/README_md.html]. The managed loop sets up the terminal and restores it on exit, even after crashes. RatatuiRuby.run do |tui| loop do tui.draw do |frame| frame.render_widget( tui.paragraph(text: "Hello, RatatuiRuby!", alignment: :center), frame.area ) end case tui.poll_event in { type: :key, code: "q" } then break else nil end end end ==== Widgets included: [Layout] {Block}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_block/README_md.html], {Center}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_center/README_md.html], {Clear (Popup, Modal)}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_popup/README_md.html], {Layout (Split, Grid)}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_layout_split/README_md.html], {Overlay}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_overlay/README_md.html] [Data] {Bar Chart}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_barchart/README_md.html], {Chart}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_chart/README_md.html], {Gauge}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_gauge/README_md.html], {Line Gauge}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_line_gauge/README_md.html], {Sparkline}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_sparkline/README_md.html], {Table}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_table/README_md.html] [Text] {Cell}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_cell/README_md.html], {List}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_list/README_md.html], {Rich Text (Line, Span)}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_rich_text/README_md.html], {Scrollbar (Scroll)}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_scrollbar/README_md.html], {Tabs}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_tabs/README_md.html] [Graphics] {Calendar}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_calendar/README_md.html], {Canvas}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_canvas/README_md.html], {Map (World Map)}[https://www.ratatui-ruby.dev/docs/v0.10/examples/widget_map/README_md.html] Need something else? {Build custom widgets}[https://www.ratatui-ruby.dev/docs/v0.10/doc/concepts/custom_widgets_md.html] in Ruby! --- === Testing Built In TUI testing is tedious. You need a headless terminal, event injection, snapshot comparisons, and style assertions. RatatuiRuby bundles all of it. require "ratatui_ruby/test_helper" class TestColorPicker < Minitest::Test include RatatuiRuby::TestHelper def test_swatch_widget with_test_terminal(10, 3) do RatatuiRuby.draw do |frame| frame.render_widget(Swatch.new(:red), frame.area) end assert_cell_style 2, 1, char: "█", bg: :red end end end ==== What's inside: - Headless terminal — No real TTY needed - Snapshots — Plain text and rich (ANSI colors) - Event injection — Keys, mouse, paste, resize - Style assertions — Color, bold, underline at any cell - Test doubles — Mock frames and stub rects - UPDATE_SNAPSHOTS=1 — Regenerate baselines in one command --- ==== Inline Menu Example require "ratatui_ruby" # This example renders an inline menu. Arrow keys select, enter confirms. # The menu appears in-place, preserving scrollback. When the user chooses, # the TUI closes and the script continues with the selected value. class RadioMenu CHOICES = ["Production", "Staging", "Development"] # ASCII strings are universally supported. PREFIXES = { active: "●", inactive: "○" } # Some terminals may not support Unicode. CONTROLS = "↑/↓: Select | Enter: Choose | Ctrl+C: Cancel" # Let users know what keys you handle. TITLES = ["Select Environment", # The default title position is top left. { content: CONTROLS, # Multiple titles can save space. position: :bottom, # Titles go on the top or bottom, alignment: :right }] # aligned left, right, or center def call # This method blocks until a choice is made. RatatuiRuby.run(viewport: :inline, height: 5) do |tui| # RatauiRuby.run manages the terminal. @tui = tui # The TUI instance is safe to store. show_menu until chosen? # You can use any loop keyword you like. end # `run` won't return until your block does, RadioMenu::CHOICES[@choice] # so you can use it synchronously. end # Classes like RadioMenu are convenient for private # CLI authors to offer "rich moments." def show_menu = @tui.draw do |frame| # RatatuiRuby gives you low-level access. widget = @tui.paragraph( # But the TUI facade makes it easy to use. text: menu_items, # Text can be spans, lines, or paragraphs. block: @tui.block(borders: :all, titles: TITLES) # Blocks give you boxes and titles, and hold ) # one or more widgets. We only use one here, frame.render_widget(widget, frame.area) # but "area" lets you compose sub-views. end def chosen? # You are responsible for handling input. interaction = @tui.poll_event # Every frame, you receive an event object: return choose if interaction.enter? # Key, Mouse, Resize, Paste, FocusGained, # FocusLost, or None objects. They come with move_by(-1) if interaction.up? # predicates, support pattern matching, and move_by(1) if interaction.down? # can be inspected for properties directly. quit! if interaction.ctrl_c? # Your application must handle every input, false # even interrupts and other exit patterns. end def choose # Here, the loop is about to exit, and the prepare_next_line # block will return. The inline viewport @choice # will be torn down and the terminal will end # be restored, but you are responsible for # positioning the cursor. def prepare_next_line # To ensure the next output is on a new area = @tui.viewport_area # line, query the viewport area and move RatatuiRuby.cursor_position = [0, area.y + area.height] # the cursor to the start of the last line. puts # Then print a newline. end def quit! # All of your familiar Ruby control flow prepare_next_line # keywords work as expected, so we can exit 0 # use them to leave the TUI. end def move_by(line_count) # You are in full control of your UX, so @choice = (@choice + line_count) % CHOICES.size # you can implement any logic you need: end # Would you "wrap around" here, or not? # def menu_items = CHOICES.map.with_index do |choice, i| # Notably, RatatuiRuby has no concept of "\#{prefix_for(i)} \#{choice}" # "menus" or "radio buttons". You are in end # full control, but it also means you must def prefix_for(choice_index) # implement the logic yourself. For larger return PREFIXES[:active] if choice_index == @choice # applications, consider using Rooibos, PREFIXES[:inactive] # an MVU framework built with RatatuiRuby. end # Or, use the upcoming ratatui-ruby-kit, # our object-oriented component library. def initialize = @choice = 0 # However, those are both optional, and end # designed for full-screen Terminal UIs. # RatatuiRuby will always give you the most choice = RadioMenu.new.call # control, and is enough for "rich CLI puts "You chose \#{choice}!" # moments" like this one. --- === Full App Solutions RatatuiRuby renders. For complex applications, add a framework that manages state and composition. ==== Rooibos[https://www.rooibos.run] (Framework) Model-View-Update architecture. Inspired by Elm, Bubble Tea, and React + Redux. Your UI is a pure function of state. - Functional programming with MVU - Commands work off the main thread - Messages, not callbacks, drive updates ==== {Kit}[https://sr.ht/~kerrick/ratatui_ruby/#chapter-3-the-object-path--kit] (Coming Soon) Component-based architecture. Encapsulate state, input handling, and rendering in reusable pieces. - OOP with stateful components - Separate UI state from domain logic - Built-in focus management & click handling Both use the same widget library and rendering engine. Pick the paradigm that fits your brain. --- === Why RatatuiRuby? Ruby deserves world-class terminal user interfaces. TUI developers deserve a world-class language. RatatuiRuby wraps Rust's Ratatui via native extension. The Rust library handles rendering. Your Ruby code handles design. >>> "Text UIs are seeing a renaissance with many new TUI libraries popping up. The Ratatui bindings have proven to be full featured and stable." — {Mike Perham}[https://www.mikeperham.com/], creator of Sidekiq[https://sidekiq.org/] and Faktory[https://contribsys.com/faktory/] ==== Why Rust? Why Ruby? Rust excels at low-level rendering. Ruby excels at expressing domain logic and UI. RatatuiRuby puts each language where it performs best. ==== Versus CharmRuby CharmRuby[https://charm-ruby.dev/] wraps Charm's Go libraries. Both projects give Ruby developers TUI options. [Integration] CharmRuby: Two runtimes, one process. RatatuiRuby: Native extension in Rust. [Runtime] CharmRuby: Go + Ruby (competing). RatatuiRuby: Ruby (Rust has no runtime). [Memory] CharmRuby: Two uncoordinated GCs. RatatuiRuby: One Garbage Collector. [Style] CharmRuby: The Elm Architecture (TEA). RatatuiRuby: TEA, OOP, or Imperative. --- === Links [Get Started] {Quickstart}[https://www.ratatui-ruby.dev/docs/v0.10/doc/getting_started/quickstart_md.html], {Examples}[https://www.ratatui-ruby.dev/docs/v0.10/examples/app_cli_rich_moments/README_md.html], {API Reference}[https://www.ratatui-ruby.dev/docs/v0.10/], {Guides}[https://www.ratatui-ruby.dev/docs/v0.10/doc/index_md.html] [Ecosystem] Rooibos[https://www.rooibos.run], {Kit}[https://sr.ht/~kerrick/ratatui_ruby/#chapter-3-the-object-path--kit] (Planned), {Framework}[https://sr.ht/~kerrick/ratatui_ruby/#chapter-5-the-framework] (Planned), {UI Widgets}[https://sr.ht/~kerrick/ratatui_ruby/#chapter-6-licensing] (Planned) [Community] {Forum}[https://forum.setdef.com/c/ratatui-ruby/6], {Announcements}[https://forum.setdef.com/tags/c/ratatui-ruby/6/announcement], {Discussion}[https://forum.setdef.com/tags/c/ratatui-ruby/6/discussion], {Bug Tracker}[https://forum.setdef.com/tags/c/ratatui-ruby/6/bug] [Contribute] {Contributing Guide}[https://man.sr.ht/~kerrick/ratatui_ruby/contributing.md], {Code of Conduct}[https://man.sr.ht/~kerrick/ratatui_ruby/code_of_conduct.md], {Project History}[https://man.sr.ht/~kerrick/ratatui_ruby/history/index.md], {Pull Requests}[https://forum.setdef.com/tags/c/ratatui-ruby/6/patch] --- [Website] https://www.ratatui-ruby.dev [Source] https://github.com/setdef/RatatuiRuby [RubyGems] https://rubygems.org/gems/ratatui_ruby [Upstream] https://ratatui.rs [Build Status] https://builds.sr.ht/~kerrick/ratatui_ruby © 2026 Kerrick Long · Library: LGPL-3.0-or-later · Website: CC-BY-NC-ND-4.0 · Snippets: MIT-0