brain

A native macOS code editor / IDE whose entire UI is pure Krypton on the objk Objective-C FFI — no Obj-C, no Swift source. A real Cocoa app (NSWindow, NSTextView, NSOutlineView, menus) driven by Krypton functions used directly as Objective-C method IMPs.

Features

• File-tree sidebar with directory navigation, multi-file tabs (with close ✕)
• Multi-language syntax highlighting (k/ks, js, ts, py, c, go, rs, sh, rb, json, …)
• A real interactive terminal pane (live zsh on a pty, the stem grid engine)
• File menu (New/Open/Open Folder/Open Recent/Save/Save As/Save All/Auto Save…), Edit (undo/redo/find/replace), View (toggle sidebar/terminal, font zoom), Run
• Native file/folder pickers, recent files/folders

Install

brew install --cask t3m3d/krypton/brain

Build from source

Needs a Krypton checkout (the toolchain):

KRYPTON=/path/to/krypton kr build.ks    # -> brain.app

Source of record: brain.ks (here). The older gui_editor.m is retained for reference; app builds use Objective K.

All build and install entry points are KryptScript (.ks), executed with kr (or kcc -r). Run them from this checkout; set KCODE_ROOT when running elsewhere. The installed macOS toolchain is used by default; KRYPTON selects an alternate checkout.

kr build_app.ks             # -> dist/brain.app (make-app.ks does the same)
kr install.ks               # -> ~/Applications/brain.app
kr install.ks /Applications # optional destination; must be writable
kr kcc.ks --version         # forwards to the installed native driver

brain.icns is optional. Build failures preserve the existing app. The editor restores kcode's charcoal palette, native toolbar, split panes, blue active tabs, line-number gutter, minimap, and cursor status through Objective K's Cocoa bindings. The app menu includes Quit (⌘Q); View → Toggle Terminal (⌘J) expands/collapses and focuses the terminal. Long lines scroll horizontally so gutter numbers stay aligned. Explorer expands folders lazily and shows nested files. Quick Open (⌘P) searches project paths; Command Palette (⌘⇧P) searches editor actions. New Text File uses ⌘N. Both pickers support Enter, Escape, and arrow keys.

Release work

The Objective K app is a development preview. Release acceptance and remaining issues are tracked in docs/RELEASE_READINESS.md.

kr build.ks
brain.app/Contents/MacOS/brain --self-test # native regression checks; reliable exit status
kr build_store.ks              # sandboxed editor-only preview in dist/

The Store preview omits the terminal and external compiler. The full developer edition remains available. Store previews use ad-hoc signing for local sandbox testing; they are not signed archives suitable for App Store submission.

The kr wrapper currently masks native child exit codes. CI should invoke the compiled app directly for regression checks, and compile release-check scripts with kcc --native release_check.ks -o /tmp/brain-release-check, then run /tmp/brain-release-check.