RatatuiRuby: Ruby gem wrapping Rust Ratatui for building terminal user interfaces.

What it does

RatatuiRuby is a Ruby gem that wraps Ratatui, a Rust-based terminal user interface library. It lets developers build rich terminal UIs—spinners, progress bars, menus, and other interactive elements—while writing in Ruby rather than Rust. The gem is installed via gem install ratatui_ruby and exposes Ratatui's capabilities through a Ruby API.

Who it is for

Ruby developers building command-line tools who want to add visual polish without sacrificing performance. This targets CLI authors who need spinners, progress indicators, or selection menus but want to stay in the Ruby ecosystem. It suits projects where a full-screen terminal takeover is undesirable and inline UI elements are preferable.

Pricing

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How it stands out

Two features differentiate this from other Ruby terminal UI tools. First, the inline viewport model preserves terminal scrollback history. Most terminal UI libraries erase themselves on exit, losing user output. RatatuiRuby's inline mode occupies a fixed number of lines, renders the UI, then leaves the content in place when done. Second, it combines Rust's native performance with Ruby's developer experience. The documentation emphasizes low-level access alongside a facade layer, letting developers choose between convenience and control. The examples show self-contained classes for common patterns like radio menus, suggesting an opinionated but pragmatic API design.

What a founder should check

A rival builder should verify three things. First, examine whether the Rust-wrapping approach introduces meaningful latency or resource overhead compared to pure-Rust implementations or simpler Ruby alternatives. Second, assess switching costs: how difficult is it to migrate an existing CLI from another Ruby TUI library to RatatuiRuby, and does the inline viewport model lock users into that pattern? Third, understand the moat. Ratatui itself is maintained externally, so the gem's defensibility depends on the quality of the Ruby binding and the ecosystem around it. Check whether there are barriers to competitors forking or reimplementing the wrapper, or whether network effects from a growing Ruby TUI community will drive adoption.

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