@arcturn/tui

Internal to the arcturn CLI. Published so arcturn resolves; its API may change in any release without a major version bump. Embedders should depend on @arcturn/core and @arcturn/ai, whose surfaces are the ones the SDK documents.

A from-scratch terminal UI library with differential rendering, built for the Arcturn CLI but standalone and independently usable. It depends only on marked and get-east-asian-width, and every terminal interaction goes through a Terminal interface, so the whole library can be driven headlessly (see TestTerminal) — useful for snapshot-testing a TUI without a real tty.

What's in it

src/index.ts groups exports by area:

• ANSI + styling — fg, bg, bold, dim, italic, underline, hyperlink, combine, makeStyle, stripAnsi, detectColorLevel, cursor/erase control sequences.
• Components (./components/index.js) — the widget set (editor, text, layout, etc.) built on the renderer below.
• Images — renderImage, encodeKittyImage, encodeItermImage, detectImageSupport for terminals that support inline image protocols.
• Key decoding — KeyDecoder, createKey, matchesKey, keyToString.
• Terminal — Terminal (the interface), ProcessTerminal (a real tty), and TestTerminal (an in-memory terminal for tests).
• Theming — createTheme, getTheme/setTheme, darkTheme, lightTheme, style.
• Renderer — TUI, the root component tree and differential-rendering engine, plus Component, KeyHandler, and overlay-positioning types.
• Width, wrapping, truncation — East-Asian-width-aware string measurement.

Install

Arcturn is not yet published to npm. Until it is, use it from a clone of the monorepo as a pnpm workspace package:

git clone https://github.com/sitharaj88/arcturn.git && cd arcturn
pnpm install && pnpm -r build

Then depend on it from another workspace package: "@arcturn/tui": "workspace:*".

Usage

import { Editor, ProcessTerminal, Text, TUI } from "@arcturn/tui";

const tui = new TUI(new ProcessTerminal());
const editor = new Editor({ onSubmit: (text) => console.log(text) });
tui.add(new Text("Ask me anything", { style: "accent" }));
tui.add(editor);
tui.focus(editor);
tui.start();

Docs

@arcturn/tui powers the arcturn CLI's terminal interface; there is no dedicated SDK page for it yet. See Embedding with the SDK for how the CLI, this library, and the agent runtime relate, and the Arcturn documentation index for what's covered so far.

License

Apache-2.0 — see LICENSE.

👤 Author

Sitharaj Seenivasan

• 🌐 Website: sitharaj.in
• 💼 LinkedIn: sitharaj08
• 💻 GitHub: sitharaj88

☕ Support

If this project helps you, consider buying me a coffee — it keeps the work going.

📄 License

Licensed under the Apache License 2.0. © 2026 Sitharaj Seenivasan.