@term-ui/core

The term-ui engine: a miniature browser engine for the terminal, written in Zig and compiled to WebAssembly, with a thin TypeScript wrapper.

This package is the bottom of the stack. Most applications should use @term-ui/react (React) or @term-ui/dom (imperative DOM-style API) instead of talking to it directly.

What's in here

The same pipeline a browser runs, sized for a terminal:

• DOM tree — nodes, attributes, styles
• Layout tree — block and flex layout with anonymous boxes, mirroring the resolved DOM
• Text pipeline — CSS whitespace rules, wrapping, alignment, grapheme-aware widths
• Render list — the paint-order display list, with clipping and scroll offsets
• Renderer — diffing painter that only rewrites the cells that changed
• Selection — WebKit-style caret-from-point, ranges, word and line granularity
• Terminal input — kitty keyboard protocol, SGR mouse, legacy fallbacks, parsed into events

Usage

import { init } from "@term-ui/core";
import { loader } from "@term-ui/core/node";

const module = await init({ loader });

module is the instantiated WASM export surface. Entry points:

| Entry | Contents | |---|---| | @term-ui/core | init, the Module type, shared types | | @term-ui/core/node | Node loaders (loader, initFromFile, distDir) | | @term-ui/core/constants | Enums shared with the engine (hit-test filters, event codes) | | @term-ui/core/core.wasm | Release build, for custom loaders | | @term-ui/core/core-debug.wasm | Debug build with allocation tracking and leak detection |

Memory

The engine owns its allocations. Values crossing the boundary are copied into JS before the next call, so returned strings and arrays are safe to hold; handles such as trees and selections are disposed explicitly by their owner. The debug build tracks every allocation, so a test can assert a session leaked nothing.

Building from source

Requires Zig at the version pinned in .zigversion at the repo root — the code tracks Zig master, so the pin is exact and deliberate.

pnpm build:wasm:all   # debug + release builds into dist/
zig build test        # engine test suite

License

MIT — see LICENSE.