pi-theme-switcher

Pi extension that automatically switches the terminal theme between dark and light based on environment variables, THEME_MODE, or time of day.

Installation

pi install npm:pi-theme-switcher

How it works

On TUI session start, the extension evaluates the theme in this order:

1. PI_AGENT_THEME — set to "dark" or "light" to force a theme
2. THEME_MODE — set to "night" (dark) or "day" (light)
3. Time of day — fallback to dark/light based on system clock (configurable window)

The extension polls every 60 seconds to handle time-based transitions during long TUI sessions. It does not run in RPC, print, or JSON sessions where no terminal TUI theme can be changed.

Configuration

Create a config file at ~/.pi/agent/theme-switcher.json (global) or .pi/agent/theme-switcher.json (project-local):

{
  "nightStart": 22,
  "nightEnd": 6
}

• nightStart (default: 23, 11 PM) — hour to switch to dark mode
• nightEnd (default: 7, 7 AM) — hour to switch to light mode

Configure both fields together, or omit both to use defaults. A config with only one of these fields is ignored.

When nightStart > nightEnd (e.g., 22–6) the night range wraps around midnight. When nightStart <= nightEnd (e.g., 0–5), it does not.

Project config overrides global config when it provides both fields.

License

MIT