letui

demo.mp4

TUI library written using Rust and TypeScript

Dependencies:

• crossterm - cross-platform terminal manipulation library
• taffy - UI layout engine

TODO

• scrolling support
• better text styling user API: add TextChunk type { text: string; fg?: number; bg?: number; bold?: boolean }
• better text input: multi-line and shortcuts
• verify DX for supporting syntax highlighting
• persistent taffy tree
• (experiment) Neovim as text input (see Bun PTY support)
• refactor flush with BatchWriter pattern
• add performance stats overlay (runs independently)

NPM publish notes:

1. push your changes
2. update versions in Cargo.toml and package.json
3. git tag v0.0.1 - tag a commit
4. git push origin v0.0.1 - push the tag
5. release action will build and deploy it as package

Benchmark Results (letui vs Rezi) - may not be accurate, just playing around right now

Latest run: 2026-02-20 (terminal-rerender, full profile, PTY mode)

Run config:

• warmup=100
• iterations=1000
• replicates=7 (first replicate discarded)
• command: bun run bench/run.ts --profile full --scenario terminal-rerender

Metric	letui	Rezi	Delta
Mean latency	20 us	259 us	letui 12.69x faster
p95 latency	21 us	260 us	letui lower
Throughput	48.6K ops/s	3.9K ops/s	letui 12.46x higher
Peak RSS	60.4 MB	128.2 MB	letui 2.12x lower
PTY bytes	43.2 KB	30.1 KB	letui 1.43x higher