A minimalistic modal text environment, containing your code without distraction.

_{site  ·  releases  ·  claw  ·  org}

紙 Kami: file explorer	Split panes + 零 Rei AI
Editor help overlay	Theme picker · 17 presets

零 Rei lives inside Hako; powered by hakoCLAW:

 ▄█████▄
██ ███ ██ Rei: v1.1
█████████ Provider: You Choose
▀█▀▀█▀▀█▀ Model: You Choose

_{—— I ——}

Overview

• Modal Editing: Vim-inspired normal, insert, visual, and visual-line modes
• Full Motion Set: counts, named registers, text objects (diw, ci", da(), marks, jumplist, dot-repeat, :s/ substitution, bracket match
• Multi-Pane Support: Split horizontally and vertically, resize with Ctrl-W +/-/</>
• File Explorer: 紙 Kami - directory navigation, hidden-file toggle, dirs-first sort
• AI Assistant: 零 Rei - multi-provider (Anthropic, OpenAI, Ollama), function-calling tool loop, SSE streaming, per-project trust and history
• Skills: drop ~/.hako/skills/*.md into the system prompt, install from any URL with /skill install
• Syntax Highlighting: 40+ languages, search-match highlighting persists across edits
• Undo/Redo: time-bounded undo blocks, configurable depth
• Visual Selection: character and line modes with yank/delete/change, count feedback
• Clipboard: bracketed paste, system clipboard via Ctrl-C/Ctrl-V
• Fast Search: incremental with n/N, all matches highlighted
• Line Numbers: absolute or relative, dynamic width
• Mouse Support: click to position, scroll wheel moves cursor
• 17 Themes: dark, light, gruvbox, nord, dracula, monokai, solarized, tokyonight, catppuccin, onedark, material, everforest, rosepine, github-dark, github-light, ayu, kanagawa
• Customizable: every setting in .hakorc, model/provider choices persist in ~/.hako/state

_{—— II ——}

Build

# One-liner - works on Linux, macOS, Windows (mingw)
gcc hako.c -o hako -lpthread

# Or use the Makefile to also embed the executable icon where the OS allows
make

Run

./hako              # or  ./hako [filename]

Install (drop the binary into your PATH):

cp hako /usr/local/bin/hako          # Linux / macOS

Deps: C standard library + POSIX/Win32 system headers + pthread. No third-party libraries linked. AI features shell out to curl(1) at runtime.

Executable icon

The icon files live in icon/:

Platform	File	What make does
Windows	hako.ico	Embeds icon into .exe via windres; real OS icon.
macOS	hako.icns	Attaches icon as a resource fork via Rez+SetFile (Xcode CLT). Best-effort.
Linux	hako.png	ELF can't embed icons; ship hako.png and reference it from a .desktop file.

A plain gcc hako.c -o hako produces a working binary on every platform; the icon is purely cosmetic.

iSh (iOS - experimental)

hako compiles on Alpine via iSh:

apk add gcc make musl-dev curl
make

Notes:

• AI panel needs curl for HTTPS requests; apk add curl is required before using Rei.
• Narrow screens auto-stack the AI panel below the editor instead of squeezing horizontally.
• iSh runs single-threaded under emulation; expect slower stream rendering.

_{—— III ——}

Key Bindings

Normal Mode

Key	Action
i	Enter insert mode
I	Insert at first non-blank
a	Append after cursor
A	Append at end of line
o	Open line below
O	Open line above
v	Visual mode (character)
V	Visual mode (line)
h,j,k,l	Navigate (←↓↑→)
w,b	Next/previous word
0,$	Start/end of line
gg,G	Top/bottom of file
dd	Delete line (yanks)
D	Delete to end of line
x	Delete character
C	Change to end of line
yy	Yank (copy) line
p,P	Paste after/before
u	Undo
Ctrl-R	Redo
r	Replace character
J	Join lines
/	Search
n,N	Next/previous match
Ctrl-C	Copy to system clipboard
Ctrl-V	Paste from system clipboard
:w	Save
:e [filename]	Open file
:q	Quit
:wq	Save and quit
Ctrl-F	Page forward
Ctrl-B	Page backward

Visual Mode

Key	Action
h,j,k,l	Extend selection
w,b	Word-wise selection
0,$	Select to start/end
gg,G	Select to top/bottom
Ctrl-F	Page forward selection
Ctrl-B	Page backward selection
y	Yank selection
d,x	Delete selection
c	Change selection
Ctrl-C	Copy to system clipboard
Esc	Exit visual mode

Window Management

Key	Action
Ctrl-W s	Split horizontal
Ctrl-W v	Split vertical
Ctrl-W w	Switch pane
Ctrl-W c	Close pane

File Explorer (紙 Kami)

Key	Action
:e,:explorer	Toggle explorer
j,k	Navigate files
h,l	Parent/open
g,G	Top/bottom of list
.	Toggle hidden files
r	Refresh
q,Esc	Close explorer

AI Assistant (零 Rei)

Key	Action
:ai	Toggle AI panel
i	Enter prompt mode
Enter	In INSERT: newline. In NORMAL: send
Esc	Back to NORMAL
v	Visual select (copy-only in history)
j,k	Navigate history
Ctrl-W w	Switch pane
Ctrl-C	Close panel
:q	Close panel

Slash commands (type inside the prompt):

Command	Action
/help	List commands
/provider <name>	ollama, anthropic, openai, deepseek, mistral, together, fireworks, openrouter, groq, xai (auto-fills endpoint)
/model <id>	Switch model (persists to ~/.hako/state)
/tools on / off	Toggle function calling
/trust / /trust revoke	Grant or revoke file-ops in this project
/skills [reload]	List / reload ~/.hako/skills/*.md
/skill install <url>	Download a skill into ~/.hako/skills/
/history local / global	Show path, or move to <cwd>/.hako/history
/file <path>	Inject a local file into context
/clear	Wipe visible history
/usage	Show provider/model/trust + token totals
/sessions	List up to 16 prior sessions
/session [new]	Show session info; new resets
/resume <id>	Switch to prior session
/quit	Close the panel

Tools (when trusted): read_file, list_dir, read_open_file, list_open_files, write_file (path constrained to project; staged when ai_autowrite=0), run_shell (project must be trusted).

Pane control (any focused pane): :q rei / :q kami (also :close <name>) closes the named side panel.

_{—— IV ——}

Configuration

Use supplied config, or generate one with :config inside the editor. HAKO looks for .hakorc in the current directory first, then your home directory.

# Example .hakorc
tab_stop=4
use_tabs=1
show_line_numbers=2
auto_indent=1
smart_indent=1
mouse_enabled=1
theme=dark
explorer_width=30

# AI panel (Rei)
ai_provider=deepseek          # or anthropic | openai | ollama | mistral | ...
ai_api_key=sk-...             # not needed for ollama
ai_model=deepseek-chat
ai_max_tokens=2048
ai_tools_enabled=1
ai_stream=1
ai_autowrite=1                # 0 stages writes to <path>.hako-pending
# ai_endpoint=                # auto-set for known providers

Run :config to generate a fully documented .hakorc with all options.

_{—— V ——}

Supported Languages

HAKO provides syntax color for 40+ languages, some of which include:

Systems: C, C++, Rust, Go, Zig, Assembly
Scripting: Python, Ruby, Perl, Lua, Shell, PHP
Web: JavaScript, TypeScript, HTML, CSS, JSON
JVM: Java, Kotlin, Scala, Clojure
Functional: Haskell, OCaml, F#, Elixir
Modern: Swift, Dart, Julia, Nim
Config: YAML, TOML, Dockerfile, Makefile

_{—— VI ——}

Change Log

v0.1.0 (Latest)

Polish + portability + safety pass.

Editor / panes

• Cell-grid diff renderer: front/back buffers, minimal escape emission, no flicker
• Squished-terminal vertical pane stack: AI auto-stacks below editor when too narrow (≥ 16 rows)
• Cross-pane close: :q rei / :q kami (also :close <name>) closes named side from any focused pane
• Explorer border fix; mouse hit-testing covers all panes including stacked
• Themes: :theme <name> / :colorscheme <name> runtime switch (17 presets)
• Binary-file refuse: NUL-byte detection in first 4KB → no garbage spew on image opens

Rei (AI panel)

• Cursor in prompt: ←/→/↑/↓/Home/End, BS/DEL splice at cursor, mid-text edits
• Visual mode in chat history: j/k/gg/G/Ctrl-D/Ctrl-F/Ctrl-U/Ctrl-B/V/y/Esc/Ctrl-C/Ctrl-W
• Provider aliases: deepseek, mistral, together, fireworks, openrouter, groq, xai/grok; endpoint auto-filled
• Token tracking: /usage shows last N in / M out total ... (cap K) across Anthropic/OpenAI/Ollama
• Blockquote tint: AI lines starting > use comment color
• ai_autowrite=0 stages writes to <path>.hako-pending (line/byte diff returned)
• Sessions: /sessions, /resume <id>, /session [new]; auto-resume hint on launch
• Universal tools (Anthropic native + Ollama/OpenAI function-calling fallback)
• Per-call announcements (→ read_file(test.txt) / ← N bytes / error: ...)
• Spinner: ⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏ thinking...
• Streaming: \n sanitized live, multi-line split on stream end

Build / release

• GitHub Actions release workflow (linux/macos/windows on tag v0.1*)
• README documents iSh build (apk add gcc make musl-dev curl && make)
• Makefile unchanged for one-liner: gcc -O2 -Wall hako.c -o hako -lpthread

Previous Versions

Previous Changes

v0.0.9
Big one. HAKO goes from editor-with-AI-panel to modal editing environment with a real agent inside.

Editor

• Full vim-motion set: count prefix (5j, 3dd), named registers ("ayy, "ap), text objects (diw, ci", da(), marks (ma, 'a), jumplist (Ctrl-O / Tab), dot-repeat (.), substitution (:s/foo/bar/g), bracket match (%), word-under-cursor search (*, #)
• Search highlighting persists across edits, all matches lit (not just current)
• Line-delete feedback in status (N lines deleted)
• :e expands ~/, resolves relative and absolute paths so :w saves where you meant
• :q closes the active pane, not the whole program
• dw, cw, :w file.txt confirmed working
• 17 theme presets (dark, light, gruvbox, nord, dracula, monokai, solarized, tokyonight, catppuccin, onedark, material, everforest, rosepine, github-dark, github-light, ayu, kanagawa)
• Responsive layout; side panels auto-collapse on narrow terminals
• Explorer entries always sorted: directories first, then files, case-insensitive
• Status bar now uses the border color so panels feel like one chassis

Rei 零

• Multi-provider: Anthropic, OpenAI, Ollama (swap with /provider)
• Function-calling tool loop (Anthropic): read_file, list_dir, write_file, run_shell
• SSE streaming for text responses
• Project trust: first :ai asks before enabling file tools in a directory; grants stored in <project>/.hako/trust
• Per-project chat history in <project>/.hako/history when trusted, falls back to ~/.hako/history
• Skills loader: ~/.hako/skills/*.md injected into system prompt; /skill install <url> downloads a skill
• Multi-line input: Enter inserts newline in INSERT, sends in NORMAL. Input bar wraps and stays visible
• Slash commands: /help, /provider, /model, /tools, /trust, /skills, /skill install, /history, /file, /clear, /quit
• Model + provider choice persists across restarts (~/.hako/state)
• Configurable mascot (ai_mascot=path/to/art.txt), lucky-cat default

Fixes

• Pane focus no longer dangles when a side panel is closed from inside it
• Ctrl-W back from Rei does not lock the terminal
• Inline prompt reads ("a, di", ma, r) skip mouse-motion events instead of consuming them as the expected letter
• Splash logo + status bar now theme-aware (match border color)
• Cursor lands in the selected explorer entry and in the Rei input bar instead of the status line
• Window-size changes resize panes immediately instead of drifting until the next SIGWINCH

v0.0.8
Major stability and usability update Features

• Bracketed paste mode support; no more staircase indentation on paste
• Rapid-input paste detection fallback for terminals without bracketed paste
• System clipboard integration (Ctrl-C to copy, Ctrl-V to paste)
• New vim motions: I, a, A, o, O (insert variants), x (delete char), D (delete to EOL), C (change to EOL)
• Visual mode navigation: w/b, 0/$, gg/G, Ctrl-F/Ctrl-B for fast selection
• dd now yanks the deleted line into the paste buffer (vim behavior)
• Scroll wheel moves cursor naturally (like j/k) instead of jumping the viewport
• Mouse click works in insert mode without producing artifacts
• Dynamic line number width; scales for 10,000+ line files
• Improved terminal type detection (Apple Terminal 256-color support)
• Improved ANSI color fallback for basic terminals (visual selection visible everywhere)

Bug Fixes

• Fixed file save writing to wrong location when opened from a path
• Fixed pane tree memory leaks on close and exit
• Fixed right panel (AI) not being freed on cleanup
• Reduced screen flicker via buffer optimization (geometric growth in append buffer)
• Consistent naming across codebase (紙 Kami = explorer, 角 Kaku = AI)
• Explicit smart_indent initialization

v0.0.7
Huge update to the previous version

• New splash screen
• Complete visual mode implementation (v/V)
• Full copy/paste system with yank buffer
• Additional vim motions (w/b, 0/$, r, J)
• Screen splitting
• 紙 Kami explorer panel
• 角 Kaku AI assistant panel (scaffolding)
• Enhanced help system
• Improved terminal cleanup
• Themes in .hakorc
• Config generation via :config command
• Mouse support with click-to-position and scroll wheel

v0.0.6
Features & Quality of Life

• Full visual mode implementation (v for character, V for line selection)
• Complete copy/paste system with yank buffer (y to copy, p/P to paste)
• Additional vim motions: w/b (word movement), 0/$ (line start/end)
• Character replacement with r, line joining with J
• Enhanced help system (:help in editor, -h/--help from command line)
• New file creation - editing non-existent files creates them on save
• Improved terminal cleanup on exit

Bug Fixes

• Fixed undo/redo segfault when undoing paste operations
• Resolved terminal color persistence after exit
• Corrected visual selection boundary handling
• Fixed edge cases with empty line selections

v0.0.5
Features & Quality of Life

• While I'm not looking to create another neovim, there are many features of vim I do enjoy
• More vi-like functionality with undo (u in normal)/redo (ctrl + r in normal) blocks
• Undo blocks function with time, action, and mode based boundaries
• Configurable undo levels, located in .hakorc (default=100)
• Options for number and relative number mode, replacing (ex. "~" with "1") available in .hakorc
• Number mode currently supports up 4 characters (ex. 9999 lines)

Bug Fixes

• Fixed terminal crashing from invalid line jumps
• Corrected cursor positioning and edge cases pertaining to empty file navigation
• Removed duplicate code and minor debug output left in from previous testing

v0.0.4

• Added familiar vi-inspired modes & commands (normal & insert, /, :, :w, :wq, :q)
• Line jump function via :NUMBER (ex. :120 goes to line 120)
• Ctrl + f pages fwd ctrl + b pages bwd

v0.0.3

• Implemented tt (go to line 1) and bb (go to last line) normal mode shortcuts
• Improved the fuzzy find triggered by /, use arrow keys or scroll to move between finds, enter/esc to exit
• Added language support for c++, c#, java, Rust, SQL, HTML/CSS, and Javascript (in addition to Python & C)

v0.0.2

• Established default font color theme, found in .hakorc
• Alternate-screen & clean exit, wiping the terminal

v0.0.1

• Initial push
• Basic text editing
• Ability to save and load files

_{—— VII ——}

Roadmap

• Windows parity
• Diff-render (fewer redraws)
• In-editor slash menus for themes and settings
• Write-file diff preview with confirm
• OpenAI/Ollama tool parity
• Buffer list (:ls, :b)

_{—— VIII ——}

Contributing

If you share the belief that simplicity empowers creativity, feel free to contribute.

Contribution is welcome in the form of:

• Forking this repo
• Submitting a Pull Request
• Bug reports and feature requests

Please ensure your code follows the existing style. I realize the single file is a personal choice, though if you choose to assist, I have divided the code.

Sections of codebase are as follows:

1. Includes
2. Defines
3. Enums
4. Struct Declarations
5. Function Prototypes
6. Syntax Highlighting
7. Terminal
8. Buffer
9. Helpers
10. Color
11. Clipboard
12. Pane Management
13. Row Operations
14. Editor Operations
15. Cursor Movement
16. Scrolling
17. Visual Mode
18. Undo/Redo
19. Search
20. File I/O
21. Drawing
22. Input
23. Mode and Commands
24. Main Drawing Functions
25. Input Processing
26. Splash Screen
27. Explorer
28. AI Assistant
29. Init
30. Main

Thank you for your attention.

This project started out of curiosity and a simple C text editor tutorial. If you hit any issues, feel free to open an issue on GitHub. Pull requests, suggestions, or even thoughtful discussions are welcome.

_{— SEE LICENSE —  ·  GPL-3.0}

_{— deus sol invictus mithras —}