theme-sync

Synchronize theme preferences across multiple terminal tools based on your GNOME appearance settings.

While many tools now support automatic theme switching based on system settings, many do not. This utility aims to bridge that gap by monitoring GNOME's theme state, then substituting theme names in configuration files.

This was a quick project to scratch my own itch!

Features

• Watch gsettings for GNOME color-scheme changes (monitor command)
• Set light/dark theme one-off (set command), optionally overriding the detected preference
• Configurable via YAML (loaded with confy)
• Supports per-app token replacements and optional reload commands

Installation

The easiest way to use theme-sync is using the snap:

# Enable the user-daemons experimental feature in snapd
snap set system experimental.user-daemons=true

# Install the snap
sudo snap install theme-sync

# Enable the app to edit files in $HOME/.config
sudo snap connect theme-sync:dot-config

# (Optional) Enable the app to send signals to other apps to reload config
sudo snap connect theme-sync:process-control

Once the snap is functional, you can also opt to start it in the background as a service:

snap start --enable --user theme-sync.daemon

You can build and install theme-sync using cargo:

cargo install --git https://github.com/jnsgruk/theme-sync

Or run with Nix:

nix run github:jnsgruk/theme-sync#theme-sync

Usage

# Apply the current system theme once
theme-sync set

# Apply a specific theme regardless of GNOME settings
theme-sync set --theme dark

# Monitor GNOME theme changes continuously
theme-sync monitor

# Use a custom configuration file
theme-sync --config /path/to/config.yaml monitor

Configuration

Configurations are stored in YAML and loaded by confy. By default, the file lives at ~/.config/theme-sync/config.yaml. If the config file does not exist, it will be created automatically.

Example configuration:

apps:
  - name: zellij
    path: .config/zellij/config.kdl
    light_token: catppuccin-latte
    dark_token: catppuccin-macchiato

  - name: helix
    path: .config/helix/config.toml
    light_token: catppuccin_latte
    dark_token: catppuccin_macchiato
    reload_cmd: pkill -USR1 hx

  - name: bottom
    path: .config/bottom/bottom.toml
    light_token: '"default-light"'
    dark_token: '"default"'

Each app entry defines:

• name: friendly label for logging
• path: file path (relative to $HOME) to update
• light_token / dark_token: strings swapped for light/dark modes
• reload_cmd: optional command run via bash -c after updating the file

Logging

The application uses env_logger with a default log level of info. Override by setting RUST_LOG, e.g.:

RUST_LOG=debug theme-sync monitor
RUST_LOG=info theme-sync monitor
RUST_LOG=warn theme-sync monitor

License

This project is licensed under the Apache 2.0 License.