sumi

A lightweight, zero-dependency system monitor for macOS, Linux, and Raspberry Pi. Written in Go, styled with the Tokyo Night color palette.

╭─ THERMAL ──────────────────────────╮ ╭─ CPU ──────────────────────────────╮
├────────────────────────────────────┤ ├────────────────────────────────────┤
│ temp   55.2°C                      │ │ load   █████████████░░░░░░░░░░░░░░░│
│ arm    1800 MHz                    │ │                                    │
│ gpu    750 MHz                     │ │ cores  4                           │
│ thrt   ok                          │ │                                    │
╰────────────────────────────────────╯ ╰────────────────────────────────────╯

╭─ Memory ───────────────────────────╮ ╭─ Disk ─────────────────────────────╮
│Total: 8.00 GiB                     │ │Mount:  /                           │
│Used:  5.12 GiB                     │ │Total:  120.00 GiB                  │
│Free:  2.88 GiB                     │ │Used:   42.30 GiB                   │
│Usage: 64.0%                        │ │Free:   77.70 GiB                   │
│████████████████████░░░░░░░░░░░░░░  │ │Usage:  35.2%                       │
│Swap:  1.50 GiB / 2.00 GiB          │ │███████████░░░░░░░░░░░░░░░░░░░░░░░  │
│███████████████████████████████░░░  │ ╰────────────────────────────────────╯
╰────────────────────────────────────╯

╭─ Network ──────────────────────────╮ ╭─ Top Processes ────────────────────╮
│Iface: eth0                         │ │NAME                   CPU%   MEM%  │
│IP:    192.168.1.42                 │ │chromium               38.0    5.2  │
│Rx:    124.6 KB/s                   │ │Xorg                   12.4    1.8  │
│Tx:    18.3 KB/s                    │ │code                    8.2    3.4  │
╰────────────────────────────────────╯ │bash                    0.5    0.1  │
                                       │sshd                    0.1    0.0  │
                                       ╰────────────────────────────────────╯

╭─ System ─────────────────────────────────────────────────────────────────────╮
├──────────────────────────────────────────────────────────────────────────────┤
│ host       raspberrypi          platform   rpi            date  2026-03-31   │
│ uptime     12d 04:21:07         time       18:42:05                          │
╰──────────────────────────────────────────────────────────────────────────────╯

Features

Disk I/O speed — real-time read/write KB/s per mount point shown under the disk bar
Network sparkline history — rolling 30-sample sparklines for Rx (green) and Tx (orange) in the Network card
Battery card — charge percentage, charging status, and time-remaining; auto-hidden on desktops/servers (no battery)
Container badges — [d] / [k] prefix in Top Processes when a process runs inside Docker or Kubernetes
Process detail panel — press d to open a per-process panel with PPID, threads, open FDs, cwd, start time, and scrolling CPU/Mem sparklines; press d or Esc to close
NDJSON streaming — --watch --renderer json emits one compact JSON object per line, pipe-friendly for jq/Grafana/Prometheus scrapers
Database monitoring (v0.9) — optional [[database]] blocks in the config file; collects connection utilization, avg/p95 query latency, throughput, lock count, replication lag, and top slow queries for PostgreSQL and MySQL/MariaDB; displayed as full-width DB cards below the System card; supports DSN via plain string, ${ENV_VAR}, or file:/path
Extended net metrics (v0.7) — established TCP connection count, gateway ping latency + packet-loss %, TCP retransmit delta, RX/TX interface errors
Extended disk metrics (v0.7) — inode saturation %, average I/O service time (AwaitMs), drive health via smartctl (ok/warn/fail)
System load (v0.7) — 1/5/15-minute load averages, uptime, file-descriptor saturation %, zombie process count, context-switches/sec
System events (v0.7) — OOM kills, disk errors, SSH failures, service restarts, reboots captured from dmesg/journalctl (Linux) and pushed to backend
WireGuard monitoring (v0.7) — peer count, online peers (last handshake <180 s), aggregate transfer bytes; cross-platform via wg show all dump
6 built-in color themes — tokyo-night (default), gruvbox, catppuccin-mocha, nord, dracula, one-dark
4 border styles — rounded (default), sharp, double, bold
Compact mode — condensed 4-line cards (--compact) for smaller terminals
Per-core CPU micro-bars — Unicode bar chart when per-core data is available
Raspberry Pi support — ARM/GPU frequency, throttle status via vcgencmd
macOS support — temperature via osx-cpu-temp (optional), swap, real Rx/Tx KB/s delta
Linux support — /proc/stat CPU delta, /proc/meminfo, /sys/class/net, thermal zone
JSON output mode — pipe-friendly, machine-readable snapshot via --renderer json
Watch mode — refresh every N seconds (--watch --interval 5)
TOML config file — persistent settings at ~/.config/sumi/config.toml
Zero runtime dependencies — single static binary

Performance

Platform	Improvement
Linux	Collect() fan-out: CPU + Net run concurrently (~1 s total vs ~2 s sequential)
macOS	CPU usage via `iostat` (lighter than `top`); Net bytes via in-process `syscall.RouteRIB` (no fork)
Both	Static data (hostname, CPU model, core count) cached on first tick — never re-queried
Both	Disk `TotalBytes` cached by mount hash — refreshed only when mounts change
Both	Single 64 KiB buffered write per TUI frame (vs 40–60 write syscalls)
Both	Keyboard events processed immediately — never blocked by slow Collect()

Interactive keybindings (watch mode)

Key	Action
`q` / `Ctrl+C`	Quit
`v`	Toggle compact / full mode
`t`	Cycle to next color theme
`j` / `k`	Move selection down / up in Top Processes
`s`	Toggle sort by CPU% / MEM%
`d`	Open process detail panel for selected process; press again or `Esc` to close
`Enter`	Prompt to send SIGTERM to selected process

Installation

Pre-built binary (recommended)

Download the binary for your platform from the Releases page.

# macOS Apple Silicon
curl -L https://github.com/denisfl/sumi/releases/latest/download/sumi-darwin-arm64.tar.gz | tar xz
sudo mv sumi /usr/local/bin/

# macOS Intel
curl -L https://github.com/denisfl/sumi/releases/latest/download/sumi-darwin-amd64.tar.gz | tar xz
sudo mv sumi /usr/local/bin/

# Linux x86_64
curl -L https://github.com/denisfl/sumi/releases/latest/download/sumi-linux-amd64.tar.gz | tar xz
sudo mv sumi /usr/local/bin/

# Linux ARM64 (Raspberry Pi 4/5)
curl -L https://github.com/denisfl/sumi/releases/latest/download/sumi-linux-arm64.tar.gz | tar xz
sudo mv sumi /usr/local/bin/

# Linux ARMv7 (Raspberry Pi 3 32-bit)
curl -L https://github.com/denisfl/sumi/releases/latest/download/sumi-linux-arm.tar.gz | tar xz
sudo mv sumi /usr/local/bin/

Build from source

git clone https://github.com/denisfl/sumi.git
cd sumi
go build -o sumi ./cmd/monitor

Requires Go 1.22 or later.

Usage

sumi [flags]

Flags:
  -w, --watch               Run in watch mode (refresh continuously)
  -n, --interval int        Refresh interval in seconds (default 5)
      --renderer string     Output renderer: tui or json (default "tui")
      --compact             Use compact (4-line) card layout
      --theme string        Color theme name (default "tokyo-night")
      --border string       Border style: rounded|sharp|double|bold (default "rounded")
      --list-themes         List available themes and exit
      --init-config         Write default config to ~/.config/sumi/config.toml and exit
      --version             Print version and exit
  -h, --help                Show help

Examples

# Single snapshot
sumi

# Watch mode, refresh every 3 seconds
sumi --watch --interval 3

# Use gruvbox theme with bold borders
sumi --theme gruvbox --border bold

# Compact layout with Catppuccin Mocha theme
sumi --compact --theme catppuccin-mocha

# List all available themes
sumi --list-themes

# JSON output (pipe-friendly)
sumi --renderer json | jq .CPU.Usage

# NDJSON streaming (one JSON object per line — for pipes, Grafana, etc.)
sumi --watch --renderer json | jq '.CPU.Usage'

Configuration

sumi reads a TOML config file at ~/.config/sumi/config.toml
(or $XDG_CONFIG_HOME/sumi/config.toml if set).

Generate default config

sumi --init-config

This writes an annotated config to ~/.config/sumi/config.toml:

# sumi configuration — https://github.com/denisfl/sumi

# Refresh interval in seconds (watch mode)
interval = 5

# Output renderer: "tui" or "json"
renderer = "tui"

# Color theme. Built-in: tokyo-night, gruvbox, catppuccin-mocha, nord, dracula, one-dark
theme = "tokyo-night"

# Card border style: "rounded", "sharp", "double", "bold"
border_style = "rounded"

# Show compact (3-line) cards instead of full detail cards
compact_mode = false

# Card order (remove a name to hide that card)
widgets = ["thermal", "cpu", "memory", "disk", "network", "processes", "system"]

[alerts]
# Alert when CPU usage exceeds threshold (0 = disabled)
cpu_threshold = 0.0
# Alert when memory usage exceeds threshold (0 = disabled)
mem_threshold = 0.0
# Alert when any disk usage exceeds threshold (0 = disabled)
disk_threshold = 0.0
# Alert when CPU temperature exceeds threshold in °C (0 = disabled)
temp_threshold = 0.0
# Emit terminal bell (\a) when an alert is active
sound = false

# ── Cloud push (optional) ───────────────────────────────────────────────────
# Set push_enabled = true and fill push_token to stream snapshots to sumi cloud.
# Get your token at https://app.getsumi.dev/settings/tokens
push_enabled  = false
push_url      = "https://ingest.getsumi.dev/v1/push"
push_token    = ""
push_interval = 60

# ── Database monitoring (optional) ──────────────────────────────────────────
# Add one [[database]] block per database to monitor.
# DSN may be a literal connection string, an env reference "${VAR}", or a
# file reference "file:/path/to/secret".

# [[database]]
# name       = "main-postgres"
# driver     = "postgres"
# dsn        = "${DATABASE_URL}"
# interval_s = 30

# [[database]]
# name       = "analytics"
# driver     = "mysql"
# dsn        = "${ANALYTICS_DSN}"
# interval_s = 60

Config options

Key	Type	Default	Description
`interval`	int	`5`	Refresh interval in seconds (watch mode)
`renderer`	string	`"tui"`	Output renderer: `tui` or `json`
`theme`	string	`"tokyo-night"`	Color theme name
`border_style`	string	`"rounded"`	Border style: `rounded`, `sharp`, `double`, `bold`
`compact_mode`	bool	`false`	Use compact card layout
`widgets`	[]string	all	Card order; remove a name to hide that card

CLI flags always override config file values.

Database monitoring

Add one [[database]] block per database to ~/.config/sumi/config.toml:

[[database]]
name       = "prod-postgres"
driver     = "postgres"
dsn        = "host=db.example.com port=5432 user=mon password=secret dbname=app sslmode=require"
interval_s = 30

[[database]]
name       = "analytics"
driver     = "mysql"
dsn        = "${MYSQL_DSN}"         # reads DSN from environment variable
interval_s = 60

Supported drivers: postgres / postgresql, mysql / mariadb.

DSN formats:

Plain string — used as-is (dev use only; prefer env var or file for credentials)
${ENV_VAR} — value read from the named environment variable at startup
file:/absolute/path — first line of the file, trimmed; suitable for secrets mounted by Docker/k8s

Each DB card shows:

Connection utilization bar (green < 60 %, yellow < 85 %, red ≥ 85 %)
Average and p95 query latency, queries-per-interval throughput
Active lock count (highlighted red if > 0), replication lag / primary label
Top slow query template (requires pg_stat_statements on PostgreSQL / performance_schema on MySQL)

The DB section is hidden entirely when no [[database]] entries are configured.

Custom themes

Place a custom TOML theme file at ~/.config/sumi/themes/<name>.toml.
User themes take precedence over built-ins with the same name.

Theme file format:

name = "my-theme"

[border]
r = 86; g = 95; b = 137

[title]
r = 122; g = 162; b = 247

[text]
r = 192; g = 202; b = 245

[green]
r = 158; g = 206; b = 106

[yellow]
r = 224; g = 175; b = 104

[red]
r = 247; g = 118; b = 142

[cyan]
r = 125; g = 207; b = 255

[purple]
r = 187; g = 154; b = 247

[orange]
r = 255; g = 158; b = 100

[teal]
r = 42; g = 195; b = 222

Once installed, the THERMAL card will show the real CPU temperature automatically.

Optional: macOS temperature

CPU temperature on macOS requires an external tool:

Intel Macs — install via Homebrew:

brew install osx-cpu-temp

Apple Silicon (M1/M2/M3/M4) — build smctemp from source:

git clone https://github.com/narugit/smctemp.git
cd smctemp
make
sudo make install

sumi tries osx-cpu-temp first, then falls back to smctemp automatically. Once either tool is installed and on $PATH, the THERMAL card will display the real CPU temperature.

Platforms

Platform	CPU	Memory	Disk	Disk I/O	Network	Thermal	Battery	Containers
macOS (Apple Silicon)	Yes	Yes	Yes	Yes	Yes	via `smctemp` (build from source)	Yes	—
macOS (Intel)	Yes	Yes	Yes	Yes	Yes	via `osx-cpu-temp` or `smctemp`	Yes	—
Linux x86_64	Yes	Yes	Yes	Yes	Yes	`/sys/class/thermal`	Yes	Docker/k8s
Raspberry Pi (arm64)	Yes	Yes	Yes	Yes	Yes	Full (vcgencmd)	—	Docker/k8s
Raspberry Pi (armv7)	Yes	Yes	Yes	Yes	Yes	Full (vcgencmd)	—	Docker/k8s

License

MIT — see LICENSE.

Made by @fedosov.me · GitHub

Name		Name	Last commit message	Last commit date
Latest commit History 23 Commits
.github		.github
cmd/monitor		cmd/monitor
docs		docs
internal		internal
.gitignore		.gitignore
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
README.md		README.md
go.mod		go.mod
go.sum		go.sum
llms.txt		llms.txt

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sumi

Features

Performance

Interactive keybindings (watch mode)

Installation

Pre-built binary (recommended)

Build from source

Usage

Examples

Configuration

Generate default config

Config options

Database monitoring

Custom themes

Optional: macOS temperature

Platforms

License

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sumi

Features

Performance

Interactive keybindings (watch mode)

Installation

Pre-built binary (recommended)

Build from source

Usage

Examples

Configuration

Generate default config

Config options

Database monitoring

Custom themes

Optional: macOS temperature

Platforms

License

About

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