# quick sanity check (does NOT start the sampler thread -- that only happens via on_start())
assert any(isinstance(p, SystemMonitor) for p in PLUGINS), "SystemMonitor should auto-register"
sm = next(p for p in PLUGINS if isinstance(p, SystemMonitor))
sm.cpu.extend([12, 34, 56, 30]); sm.ram.extend([40, 42, 41])
sm.gpu.extend([0, 5, 80]); sm.vram.extend([20, 21, 55])
panel = sm.render() # should not raise
spark = _sparkline([10, 90, 50])
assert 'polyline' in to_xml(spark).lower()
assert 'System monitor' in to_xml(panel)
print('registered plugins:', [p.name for p in PLUGINS])
print('_gpu_sample() ->', _gpu_sample()) # None if no nvidia-smi on this box; a (util%, vram%) tuple otherwise
print('_gpu_sample_darwin() ->', _gpu_sample_darwin()) # None off macOS or if ioreg has no AGXAccelerator; a bare util% otherwiseplugins
A small plugin protocol for the top bar. Each plugin supplies an icon + name, an optional always-on background task, and a
render() that builds the popup shown when its icon is activated (hover). Deliberately a leaf module – it imports only external libs, never cells.py, so cells.py can from .plugins import * without a circular import (same one-directional rule as llms.py).
The plugin protocol
Plugin is the base class: subclass it, set name/icon/trigger, and implement render() for the hover popup (plus an optional always-on background task). register is a class decorator that adds an instance to PLUGINS; start_plugins kicks off each one’s background task at server startup.
start_plugins
def start_plugins()->None:Call every registered plugin’s on_start() once. Wired into cells.py’s @app.on_event(‘startup’) so background samplers spawn on real boot only.
register
def register(
cls
):Class decorator: instantiate cls and append it to PLUGINS. Registration = importing this module. Returns cls unchanged.
Plugin
def Plugin(
*args, **kwargs
):Base class for a top-bar plugin. Subclass it, set name/icon/trigger (or in init), and override on_start/render as needed; decorate the subclass with @register to add it to PLUGINS. icon is ICONS-style path data (plain ‘d’ strings and/or (d, scale) pairs) so cells.py renders it through the exact same SVG machinery as its built-in icons. trigger is ‘hover’ (the only kind wired up so far) or ‘click’.
The system-monitor plugin
The first concrete plugin: SystemMonitor samples CPU/RAM/GPU/VRAM into ring buffers on a background thread and renders them as _sparkline mini-charts in its popup. GPU comes from _gpu_sample shelling out to nvidia-smi (the same approach as slmn.misc.gpu_free) on non-Mac hosts, or _gpu_sample_darwin reading Apple Silicon’s IOKit registry on macOS.
SystemMonitor
def SystemMonitor(
maxlen:int=300, interval:float=2.0
):*First plugin: continuously logs CPU%, system-RAM%, GPU-util%, and VRAM% into ring buffers in the background (whether or not its panel is open), and plots the accumulated history as inline-SVG sparklines when hovered. GPU comes from nvidia-smi (_gpu_sample) on non-Mac hosts or the IOKit registry (_gpu_sample_darwin) on macOS; VRAM is nvidia-only – Apple Silicon’s unified memory has no separate pool to report. Rows just go empty/‘–’ if unavailable, no separate placeholder needed.*