Huginn

A real-time system monitor for macos and linux, built with Odin.

The name Huginn is an ode to one of Odin's (Norse mythology) ravens. Huginn and Muninn (the companion raven) flew across the entire earth and the nine realms to collect information and return it to Odin.

Screenshots

Features

• CPU, memory, disk, and network monitoring
• Process listing with sort by CPU or memory
• Live updating dashboard (no page refresh)
• Native HTML, CSS, and vanilla JS frontend. No frameworks, no npm, no build step. The frontend does not modify any data from the OS/Kernel. It simply renders the dashboard
• Cross-platform: macOS and Linux

Prerequisites

• Tested with Odin dev-2026-07a
• Just command runner, optional

Quick Start

just -l # list all options
just bd # build debug
just rd # run debug on localhost port 8080

Then open http://localhost:8080 in your browser.

Manual Build

mkdir -p bin/{debug,release}
odin build server/ -debug -out:bin/debug/huginn
odin build server/ -o:speed -out:bin/release/huginn 
./bin/debug/huginn

Server Configuration and Safety

SAFETY NOTE: Server Binds to 0.0.0.0:8080 by Default. server/main.odin:14 binds to net.IP4_Any (0.0.0.0), which means the server is accessible from all network interfaces.

Here is where to make the change to loopback for safety if you prefer:

/*
Single place to change the server binding.
Default: IP4_Any (0.0.0.0) -- network-accessible.
For localhost-only, change to net.IP4_Loopback.
For a different port, change the port number.
*/
BIND_ENDPOINT :: net.Endpoint {
	address = net.IP4_Any, // change to net.IP4_Loopback
	port    = 8080,        // change to your preferred port
}

API Endpoints

• GET /: Dashboard HTML
• GET /api/host: OS and kernel info
• GET /api/metrics: CPU, memory, disk, network
• GET /api/processes?sort=cpu|mem: Top processes

API Examples

# Host info
curl http://localhost:8080/api/host

# CPU, memory, disk, network
curl http://localhost:8080/api/metrics

# Top processes
curl http://localhost:8080/api/processes

# Top processes by CPU
curl "http://localhost:8080/api/processes?sort=cpu"

# Top processes by memory
curl "http://localhost:8080/api/processes?sort=mem"

All endpoints return JSON. The metrics endpoint updates every 2 seconds and the processes endpoint every 5 seconds when viewed in the dashboard.

Architecture

Huginn has three layers:

• metrics: Platform-specific system OS/Kernel data collection
• server: HTTP server and JSON serialization (uses vendored odin-http library)
• static: Frontend dashboard (HTML, CSS, vanilla JS)

The metrics package uses a sync.Once for host info caching and a mutex-protected delta state for CPU and network rate calculations. The server uses #load to embed static files at compile time, so the binary is self-contained.

License

MIT. See LICENSE for details.

Acknowledgements

• Raven icon: "Crow standing with red key 2" from Wikimedia Commons, originally from Pixabay (CC0 1.0 Public Domain). Modified by me using Inkscape.
• HTTP server powered by odin-http