pi-quiet-spinner

Floors the frame interval of every pi-tui spinner, so a long session stops burning a core on decorative redraws.

Why

Pi redraws the whole TUI roughly 12 times per second while any spinner is on screen — the working-status indicator, the inline spinner of a running bash call, dialog loaders. Each redraw scans the entire transcript line array, not just the viewport, at roughly 0.8–1.2 µs per rendered line. A 90k-line session therefore spends most of a core merely waiting for a tool to finish; on a measured 54k-line session the difference was 58% → 8% of one core.

None of those loaders is configurable, so this package caps their frame interval globally. Rendering still happens on every real event; only the decorative tick slows down.

Install

pi install npm:pi-quiet-spinner

Or add it to ~/.pi/agent/settings.json:

{
  "packages": ["npm:pi-quiet-spinner"]
}

Presets

Style and refresh rate are one knob: a slower spinner needs a shorter animation cycle to still read as motion, so each preset pairs a frame list with an interval.

preset	Frames	Characters	Interval	Redraws	Use when
still	1	⠿	—	0/s	You want the maximum saving; the indicator stops moving and only the message text updates.
quiet	4	⠋ ⠙ ⠹ ⠸	1000 ms	1/s	Default. Keeps a visible tick at a fraction of the redraws.
calm	8	⠋ ⠙ ⠹ ⠸ ⠼ ⠴ ⠦ ⠧	400 ms	2.5/s	A middle ground for smaller sessions.
default	upstream (10)	⠋ ⠙ ⠹ ⠸ ⠼ ⠴ ⠦ ⠧ ⠇ ⠏	80 ms	12.5/s	Escape hatch: installs no patch at all.

The frames used by still, quiet and calm are prefixes of the braille cycle pi already uses (⠿ for still), so no new glyph vocabulary appears.

Configuration

Configure under the quiet-spinner key of the global ~/.pi/agent/settings.json or a project .pi/settings.json (project overrides global):

{
  "quiet-spinner": {
    "preset": "quiet"
  }
}

Key	Meaning	Default
preset	Animation preset: still, quiet, calm, or default.	quiet
intervalMs	Frame interval floor in milliseconds, an integer from 1 to 2147483647.	the preset's interval
frames	Frame list, one entry per rendered frame.	the preset's frames

The settings are read when pi loads the extension, so restart pi after editing them.

A preset supplies defaults and an explicit override always wins, including under default:

{
  "quiet-spinner": {
    "frames": ["⠋"],
    "intervalMs": 2000
  }
}

{
  "quiet-spinner": {
    "preset": "default",
    "intervalMs": 250
  }
}

The first configures a slower, motionless indicator; the second keeps pi's own frames but only 4 redraws per second.

Frame content is the whole point of the frames key, so a value that yields no frames at all — an empty list or an entry that is blank — is rejected instead of silently ignored, because it would render an invisible indicator.

Custom frame examples

You can customize "frames" with any list of non-empty strings. Common examples:

// Classic line
{
  "quiet-spinner": {
    "frames": ["-", "\\", "|", "/"],
    "intervalMs": 250
  }
}

// Blocks
{
  "quiet-spinner": {
    "frames": ["▖", "▘", "▝", "▗"],
    "intervalMs": 200
  }
}

// Pulse
{
  "quiet-spinner": {
    "frames": [" ", "▃", "▄", "▅", "▆", "▇", "█", "▇", "▆", "▅", "▄", "▃"],
    "intervalMs": 150
  }
}

// Simple dots
{
  "quiet-spinner": {
    "frames": [".", "..", "...", ".."],
    "intervalMs": 500
  }
}

An unknown key, an unknown preset, a non-integer interval, or an unreadable or unparsable settings file fails at activation with the offending value and the accepted values in the message. Pi logs the extension load error and carries on, so a broken configuration disables this package rather than the session.

The interval is always applied as a floor: max(loaderIntervalMs, configuredIntervalMs). A loader that is already slower than the configured value keeps its own interval; this package never accelerates anything.

Scope of the patch

The patch is process-wide: it affects every Loader in the process, including loaders owned by other extensions. That is the point — all of pi's spinners share the same redraw cost — but it is a global effect, so set "preset": "default" or uninstall the package to get the upstream behavior back.

The patch does not change how a loader decides to color its indicator. A loader that passed its own indicator keeps rendering it verbatim; a loader that did not keeps the theme-colored spinner path.

If @earendil-works/pi-tui no longer exposes the patched methods, activation fails with an error naming the missing method instead of silently doing nothing.

EXIT PLAN

This is a workaround for an upstream cost, not a feature.

Delete this package once upstream stops re-rendering the whole transcript per frame (issues earendil-works/pi#9549 and #6665).

Re-check by running !sleep 60 in a large session and watching ps -o time= -p <pid>: if that no longer pegs a core, the workaround is obsolete and should be removed rather than kept as a permanent patch on a dependency's prototype.

Development

npm test              # focused acceptance checks
npm run check         # type-check
npm run pack:dry-run  # verify the published file list

The tests transpile src/index.ts in memory with the runtime imports replaced by stubs, so they run under plain Node (including CI's Node 20) and under bun run without loading the TUI runtime. They exercise the option resolver and the patch contract; they do not import the real pi-tui.

License

MIT