bcon

GPU-accelerated terminal emulator for Linux console (TTY) — no X11/Wayland required.

Overview

bcon brings modern terminal features directly to the Linux console — GPU-accelerated, smooth, beautiful rendering without the desktop environment overhead.

Think of it as "Ghostty for the Linux console" — focusing on what matters: crisp text, smooth scrolling, true color, and responsive input.

Why bcon?

AI coding tools (Claude Code, Codex, Gemini CLI) have transformed development workflows. We spend less time in VSCode and more time in the terminal.

Look around — the only thing running on your X11/Wayland session might be a terminal emulator. So why not skip the desktop entirely?

bcon is the answer. It brings the modern terminal experience of Ghostty or Alacritty directly to the Linux console. GPU acceleration, True Color, Sixel/Kitty graphics, Japanese input — no X11 required.

What bcon does (and doesn't do)

bcon is the foundation layer. Leave session management and multiplexing to the tools that do it best:

Sessions: tmux (recommended), screen, zellij*
Files: yazi, ranger
Editors: Emacs, Neovim, Helix

*zellij does not support Kitty graphics protocol passthrough. Image preview in yazi won't work through zellij.

Following the Unix philosophy, bcon does one thing well: beautiful, fast rendering.

Enjoy your CLI life.

Features

Rendering

GPU Rendering: OpenGL ES via DRM/KMS + EGL + GBM
Sharp Text: Pixel-aligned glyph rendering
True Color: Full 24-bit color support
Ligatures: Font ligature support (FiraCode, JetBrains Mono, etc.)
Emoji: Color emoji rendering (Noto Color Emoji)
Powerline: Pixel-perfect Powerline/Nerd Font glyphs
HiDPI Scaling: Configurable display scale (1.0x - 2.0x)
HDR Detection: Automatic HDR capability detection from EDID

Graphics

Sixel Graphics: Display images in terminal
Kitty Graphics Protocol: Fast image transfer (direct, file, shared memory)

Terminal

Scrollback: Configurable scrollback buffer (default: 10,000 lines)
Mouse Support: Selection, wheel scroll, button events (X10/SGR/URXVT protocols)
OSC 52 Clipboard: Apps can read/write clipboard via escape sequences
Bracketed Paste: Secure paste mode support

Input

Keyboard: Full keyboard support via evdev + xkbcommon
Japanese Input: fcitx5 integration via D-Bus
IME Auto-disable: Automatically disable IME for vim/emacs/etc.
Key Repeat: Configurable key repeat delay/rate

UX

Copy Mode: Vim-like keyboard navigation for text selection
Text Search: Incremental search in scrollback (Ctrl+Shift+F)
Screenshot: Save terminal as PNG (PrintScreen or Ctrl+Shift+S)
Font Scaling: Runtime font size adjustment (Ctrl+Plus/Minus)
Monitor Hotplug: Automatic detection and switching of monitors
External Monitor Priority: Auto-switch to HDMI/DP when connected (laptops)
Visual Bell: Screen flash on bell character
URL Detection: Ctrl+Click to copy URLs

Requirements

Linux with DRM/KMS support (Debian/Ubuntu recommended)
GPU with OpenGL ES 2.0+

Installation (Debian/Ubuntu)

Basic Setup

For Japanese environment, see Japanese Environment Setup instead.

# 1. Install bcon
curl -fsSL https://sanohiro.github.io/bcon/install.sh | sudo sh
sudo apt install bcon

# 2. (Optional) Install Nerd Font for icons (yazi, lsd, etc.)
sudo apt install fontconfig curl  # if not already installed
mkdir -p ~/.local/share/fonts
cd ~/.local/share/fonts
curl -OL https://github.com/ryanoasis/nerd-fonts/releases/latest/download/Hack.tar.xz
tar xf Hack.tar.xz && rm Hack.tar.xz
fc-cache -fv

# 3. Generate config file (auto-detects Nerd Font if installed)
sudo bcon --init-config=system           # Default keybinds
sudo bcon --init-config=system,vim       # Vim-like keybinds
sudo bcon --init-config=system,emacs     # Emacs-like keybinds

# 4. Enable systemd service (tty2)
sudo systemctl disable getty@tty2
sudo systemctl enable bcon@tty2
sudo systemctl start bcon@tty2

# 5. Switch to bcon
# Ctrl+Alt+F2

Japanese Environment Setup

# 1. Install bcon and Japanese packages
curl -fsSL https://sanohiro.github.io/bcon/install.sh | sudo sh
sudo apt install bcon fonts-noto-cjk fonts-noto-color-emoji

# Minimal fcitx5 install (recommended)
# Standard fcitx5 pulls in many Qt/GTK GUI modules.
# bcon runs without X11/Wayland, so GUI is unnecessary.
# Use --no-install-recommends for minimal footprint.
sudo apt install --no-install-recommends fcitx5 fcitx5-mozc

# 2. (Optional) Install Nerd Font for icons (yazi, lsd, etc.)
sudo apt install fontconfig curl  # if not already installed
mkdir -p ~/.local/share/fonts
cd ~/.local/share/fonts
curl -OL https://github.com/ryanoasis/nerd-fonts/releases/latest/download/Hack.tar.xz
tar xf Hack.tar.xz && rm Hack.tar.xz
fc-cache -fv

# 3. Setup fcitx5 auto-start
echo 'fcitx5 -d &>/dev/null' >> ~/.bashrc
# or ~/.zshrc

# 4. Generate config file (auto-detects Nerd Font if installed)
sudo bcon --init-config=system,jp        # Default keybinds
sudo bcon --init-config=system,vim,jp    # Vim-like keybinds
sudo bcon --init-config=system,emacs,jp  # Emacs-like keybinds

# 5. Enable systemd service (tty2)
sudo systemctl disable getty@tty2
sudo systemctl enable bcon@tty2
sudo systemctl start bcon@tty2

# 6. Switch to bcon
# Ctrl+Alt+F2

# Toggle IME: Ctrl+Space (fcitx5 default)

Emacs users: Ctrl+Space conflicts with set-mark-command (C-SPC). To use Super(Win)+Space instead:

mkdir -p ~/.config/fcitx5
cat >> ~/.config/fcitx5/config << 'EOF'
[Hotkey/TriggerKeys]
0=Super+space
EOF

User Login Session (no sudo required)

Start directly from GDM/SDDM login screen:

# 1. Install bcon
curl -fsSL https://sanohiro.github.io/bcon/install.sh | sudo sh
sudo apt install bcon

# 2. Install session files
sudo cp /usr/share/bcon/bcon-session /usr/local/bin/
sudo chmod +x /usr/local/bin/bcon-session
sudo cp /usr/share/bcon/bcon.desktop /usr/share/xsessions/

# 3. Generate user config
bcon --init-config=vim,jp    # saves to ~/.config/bcon/config.toml

# 4. Select "bcon" session from login screen

Log in directly to bcon without starting a desktop environment. Saves memory and boot time.

Configuration

Config file locations:

/etc/bcon/config.toml (system config, for systemd service)
~/.config/bcon/config.toml (user config)

Available Presets

Preset	Description
`default`	Standard keybinds (Ctrl+Shift+C/V, etc.)
`vim`	Vim-like scroll (Ctrl+Shift+U/D)
`emacs`	Emacs-like scroll (Alt+Shift+V/N)
`japanese` / `jp`	CJK fonts + IME auto-disable
`system`	Write to /etc/bcon/config.toml instead of user config

Example Config

[font]
main = "FiraCode"                   # Font family name (resolved via fontconfig)
cjk = "Noto Sans CJK JP"           # or full path: "/usr/share/fonts/.../X.ttf"
emoji = "Noto Color Emoji"
symbols = "Hack Nerd Font Mono"
size = 16.0
render_mode = "lcd"
lcd_filter = "light"

[keybinds]
copy = ["ctrl+shift+c", "ctrl+insert"]
paste = ["ctrl+shift+v", "shift+insert"]
screenshot = ["printscreen", "ctrl+shift+s"]

[terminal]
scrollback_lines = 10000
ime_disabled_apps = ["vim", "nvim", "emacs", "less", "man"]

[keyboard]
repeat_delay = 400           # Key repeat delay (ms)
repeat_rate = 30             # Key repeat rate (ms)
xkb_layout = "us"            # XKB keyboard layout
xkb_options = "ctrl:nocaps"  # XKB options (Caps Lock as Ctrl)

[display]
prefer_external = true       # Prefer external monitors (HDMI/DP) over internal
auto_switch = true           # Auto-switch on hotplug connect/disconnect

[paths]
screenshot_dir = "~/Pictures"

Nerd Fonts (Icons)

For icon display in yazi, ranger, lsd, eza, fish, and Powerline prompts:

# Download and install Hack Nerd Font
mkdir -p ~/.local/share/fonts
cd ~/.local/share/fonts
curl -OL https://github.com/ryanoasis/nerd-fonts/releases/latest/download/Hack.tar.xz
tar xf Hack.tar.xz
rm Hack.tar.xz
fc-cache -fv

Configure in config.toml — font name or file path both work:

[font]
symbols = "Hack Nerd Font Mono"    # by name (recommended)
# symbols = "/usr/local/share/fonts/HackNerdFontMono-Regular.ttf"  # by path

If running via systemd (root service), install fonts system-wide:

sudo mkdir -p /usr/local/share/fonts
sudo cp ~/.local/share/fonts/HackNerdFont*.ttf /usr/local/share/fonts/
sudo fc-cache -fv

The symbols font is used as fallback for Powerline glyphs (U+E000-U+F8FF) and Nerd Font icons. If not specified, bcon auto-detects installed Nerd Fonts via fontconfig.

Note: Powerline arrow glyphs (E0B0-E0B7) are drawn programmatically for pixel-perfect rendering regardless of font.

Keybinds

Action	Default	Vim	Emacs	Description
Copy	`Ctrl+Shift+C`	same	`Ctrl+Shift+W`	Copy selection to clipboard
Paste	`Ctrl+Shift+V`	same	`Ctrl+Shift+Y`	Paste from clipboard
Screenshot	`PrintScreen`	same	same	Save screenshot as PNG
Search	`Ctrl+Shift+F`	same	`Ctrl+Shift+S`	Search in scrollback
Copy Mode	`Ctrl+Shift+Space`	same	`Ctrl+Shift+M`	Enter vim-like copy mode
Font +	`Ctrl+Plus`	same	same	Increase font size
Font -	`Ctrl+Minus`	same	same	Decrease font size
Font Reset	`Ctrl+0`	same	same	Reset font size
Scroll Up	`Shift+PageUp`	`Ctrl+Shift+U`	`Alt+Shift+V`	Scroll back
Scroll Down	`Shift+PageDown`	`Ctrl+Shift+D`	`Alt+Shift+N`	Scroll forward

Multiple keys can be assigned to a single action in config:

[keybinds]
copy = ["ctrl+shift+c", "ctrl+insert"]
paste = ["ctrl+shift+v", "shift+insert"]

Copy Mode Keys (Vim-like)

Key	Action
`h/j/k/l`	Move cursor
`w/b`	Word forward/backward
`0/$`	Line start/end
`g/G`	Top/bottom of buffer
`v`	Start/toggle selection
`y`	Yank (copy) and exit
`/`	Search
`Esc`	Exit copy mode

Other Installation Methods

Build from Source

# Build dependencies
sudo apt install \
    libdrm-dev libgbm-dev \
    libegl1-mesa-dev libgles2-mesa-dev \
    libxkbcommon-dev libinput-dev libudev-dev \
    libdbus-1-dev libwayland-dev \
    libfontconfig1-dev libfreetype-dev \
    libseat-dev \
    pkg-config cmake clang

# Rust toolchain (1.82+) required
cargo build --release

# Generate config
./target/release/bcon --init-config=vim,jp

Manual Start

Run directly from TTY (virtual console):

# Switch to TTY
Ctrl+Alt+F2

# Run bcon
sudo ./target/release/bcon

# Return to graphical session
Ctrl+Alt+F1  # or F7

Rootless Mode

bcon includes libseat support by default, enabling:

Running without root privileges
Proper session tracking (loginctl list-sessions)
Integration with screen lock, power management
Login session from GDM/SDDM

The same binary works both with sudo and as a user session.

Limitations

Multi-seat (DRM lease): Not supported. bcon uses exclusive access to the GPU.
Multiple monitors: Currently outputs to one monitor only.

License

MIT

Acknowledgments

Inspired by:

Name		Name	Last commit message	Last commit date
Latest commit History 130 Commits
.github		.github
src		src
tests		tests
.dockerignore		.dockerignore
.gitignore		.gitignore
CHANGELOG.md		CHANGELOG.md
CLAUDE.md		CLAUDE.md
Cargo.lock		Cargo.lock
Cargo.toml		Cargo.toml
Dockerfile		Dockerfile
LICENSE		LICENSE
Makefile		Makefile
README.ja.md		README.ja.md
README.md		README.md
bcon-session		bcon-session
bcon.desktop		bcon.desktop
bcon@.service		bcon@.service
docker-compose.yml		docker-compose.yml

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Repository files navigation

bcon

Overview

Why bcon?

What bcon does (and doesn't do)

Features

Rendering

Graphics

Terminal

Input

UX

Requirements

Installation (Debian/Ubuntu)

Basic Setup

Japanese Environment Setup

User Login Session (no sudo required)

Configuration

Available Presets

Example Config

Nerd Fonts (Icons)

Keybinds

Copy Mode Keys (Vim-like)

Other Installation Methods

Build from Source

Manual Start

Rootless Mode

Limitations

License

Acknowledgments

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bcon

Overview

Why bcon?

What bcon does (and doesn't do)

Features

Rendering

Graphics

Terminal

Input

UX

Requirements

Installation (Debian/Ubuntu)

Basic Setup

Japanese Environment Setup

User Login Session (no sudo required)

Configuration

Available Presets

Example Config

Nerd Fonts (Icons)

Keybinds

Copy Mode Keys (Vim-like)

Other Installation Methods

Build from Source

Manual Start

Rootless Mode

Limitations

License

Acknowledgments

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Releases 37

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