Console.Lib

A .NET library for building terminal applications with dock-based layouts, widgets, mouse/keyboard input, VT styling, and Sixel graphics rendering. AOT-compatible, targeting .NET 10.

This repo also ships mdcat — a cat-for-Markdown CLI built on the library (see below).

• Dock-based layout — top/bottom/left/right/fill panels that recompute on terminal resize, built on DIR.Lib's surface-neutral DockLayout<T> engine
• Cell-surface layout — CellLayout paints DIR.Lib's arranged LayoutNode trees (the same ones the pixel painter uses) to character cells, with click-region hit-testing
• Widget system — TextBar, TextInputBar, TextArea, ScrollableList<T>, TreeView<T>, Canvas<TSurface>, MarkdownWidget, MenuWidget
• Sixel graphics — high-performance encoder (14× faster than ImageMagick's built-in Sixel writer); plus Unicode sextant and half-block fallbacks for terminals without Sixel
• VT styling — VtStyle with 16-color SGR and TrueColor modes, automatic capability detection; StreamColor colours a CLI's plain stdout or stderr (off when redirected or under NO_COLOR, Windows VT switched on per stream)
• Markdown + LaTeX rendering — headings, tables, lists, fenced code, inline [text]{color} syntax, OSC 8 hyperlinks for clickable links, inline + display math (\(...\), $$...$$, \[...\]), \ce{...} chemistry markup, and images (![alt](path) rasterized to Sixel / blocks, with alt-text fallback). Parsing is driven by LALR.CC grammars in DIR.Lib.Markdown; Console.Lib is the VT-output layer.
• Input handling — unified keyboard + mouse events with UTF-8 codepoint decoding, SGR mouse tracking in alternate screen
• Menu system — arrow-key navigation, digit shortcuts, mouse support, alternate/normal mode
• Cross-platform — Windows VT I/O via Win32, native VT100 on Unix/macOS

dotnet add package Console.Lib

var terminal = new VirtualTerminal();
await terminal.InitAsync();

terminal.EnterAlternateScreen();

var panel = new Panel(terminal);
var statusBar = new TextBar(panel.Dock(DockStyle.Bottom, 1));
var main = panel.Fill();

statusBar.Text(" Ready").Style(new VtStyle(SgrColor.BrightWhite, SgrColor.BrightBlack)).Render();

mdcat is a tiny CLI that renders a Markdown file (or stdin) to styled terminal output using Console.Lib's MarkdownRenderer — headings, bold/italic, lists, tables, fenced code, OSC 8 hyperlinks, LaTeX math, and local images (Sixel / sextant / half-block, auto-detected). Color support is auto-detected, with a richer GitHub-Dark palette on truecolor terminals.

dotnet tool install --global mdcat   # .NET global tool (needs the .NET 10 runtime)
mdcat README.md                      # render a file
cat notes.md | mdcat -               # render from stdin

Prebuilt, self-contained native-AOT binaries (no runtime required) for Linux / Windows / macOS on x64 and arm64 are on the Releases page. See src/MdCat/README.md for all options, install methods, exit codes, and math-font details.

dotnet build src/Console.Lib
dotnet test src/Console.Lib.Tests
dotnet run --project src/MdCat -- README.md   # build & run the mdcat CLI in place

See src/Console.Lib/README.md for the full API reference, architecture diagram, and detailed usage guide.

MIT