bb-plugin-system

A live system overview inside bb — see what the machine is doing while your agents work it.

bb plugin install git:https://github.com/MGrin/bb-plugin-system.git@main

What it gives you

System panel — CPU, memory and disk tiles with status-toned meters, sparklines for the last hour, and top-process tables by CPU and by memory.

Homepage tiles — a compact CPU / memory / disk row.

bb system — the same data for agents, as text:

bb system [overview]   current snapshot with ASCII meters
bb system top          top processes by CPU and memory
bb system history [m]  compact trend for the last N minutes (default 60)

Unlike a menu-bar monitor, this keeps history: a background sampler writes to a 24-hour ring buffer, so you can answer "what was this machine doing twenty minutes ago, while that fleet was running?" — which is the question that actually comes up.

How it measures

Metrics come from systeminformation (MIT, zero dependencies), which matters more than it sounds:

• Memory uses Activity Monitor's basis (anonymous - purgeable + wired + compressed). Summing Pages active + wired + compressor — the obvious vm_stat reading — counts file-backed cache as used and misses dirty anonymous pages on the inactive queue; on a 24 GiB machine that understated real usage by over 2 GiB.
• CPU is real tick-delta utilization. Dividing load average by core count paints a large bar on an idle machine, because load counts blocked threads.
• Memory pressure is the kernel signal (kern.memorystatus_vm_pressure_level), reported separately from used/total. A Mac at 90% used with no swap activity is fine.

Sampling is adaptive — every 15s while a thread is running a turn or the panel is open, every 60s otherwise. A fixed short interval that spawns work each tick fights macOS timer coalescing to collect data nobody is reading; bb knows when work is happening, so the plugin uses that.

Top-process tables still shell ps directly: systeminformation's darwin implementation runs the same command with more columns and takes its decayed pcpu verbatim.

macOS is the tested platform; the metric library covers Linux and Windows, but the pressure reading and process table are macOS-specific.

See also get-bb/bb#1171, an open proposal for an official System Monitor plugin.

License

MIT