@nerisma/pi-tool-border

Adds a left-edge side border ▏ (in the active theme's accent color) to tool output in pi — built-in tools and extensions alike, without each tool opting in.

It works at the rendering layer, so it only borders tools whose content goes through a Box (the standard rendering path). A tool that renders its output some other way is left untouched.

Installation

pi install npm:@nerisma/pi-tool-border

Or via settings.json:

{
  "packages": ["npm:@nerisma/pi-tool-border"]
}

How it works

pi renders tool output through TUI components; none of them expose a hook for a side border, so the extension monkey-patches the Box component at module load and restores it at session_shutdown (so reloading does not stack patches).

A tool's content is rendered inside a Box whose background is set through Box.prototype.setBgFn. The extension wraps that method to record each such Box in a WeakSet, which marks exactly the boxes that belong to a tool. It then wraps Box.prototype.render: for a marked box it renders into width - 1 columns and prefixes every line with ▏, reusing the box's own background function so the border blends with the tool's background. Unmarked boxes (user messages, etc.) fall through to the original render untouched.

The edit tool draws its own framing (renderShell: "self") but its content still lives in such a Box, so it is bordered by the same mechanism — a single border, consistent with every other tool.

The border glyph is ▏ (Left Eighth Block, U+258F): a thin stroke aligned to the left of its cell, so it does not bleed the cell background the way │ does. The color comes from ctx.ui.theme.fg("accent", …), resolved on session_start; before the theme is available the extension falls back to a plain, uncolored ▏.

Compatibility

• pi >= 0.78

License

MIT © Sébastien SERVOUZE