Name: 404 Sensor
Author: LorisLabs

Overview

Your network, from every angle

The 404 Sensor is a single static binary — no runtime, no dependencies — that runs on any Linux server, Raspberry Pi, Docker container, or Mac. Once deployed, it streams real-time network telemetry back to your 404 app over an encrypted TLS connection.

Lightweight Go binary

Under 10 MB, no runtime or interpreter required. Runs on any Linux distribution, Raspberry Pi, or Mac with zero setup overhead.

Encrypted & authenticated

All traffic encrypted via TLS 1.3. HMAC-SHA256 challenge-response authentication ensures only your app can connect.

Remote diagnostics

Run ping, traceroute, port scans, and DNS lookups from the sensor’s network perspective — invaluable for diagnosing remote site issues.

CVE database sync

Syncs the NVD vulnerability feed so your 404 app can correlate discovered services against known CVEs in real time.

Auto-reconnect & buffering

Sensor results are buffered locally when the app is offline and synced automatically when the connection is restored.

Web dashboard

A lightweight read-only web dashboard is available at http://sensor-ip:4040 for quick browser-based status checks.

Quick Start

Up and running in 3 steps

1

Download

Select your platform and run the command below.

# Linux x86-64 (servers, VMs, Proxmox)
$ curl -fsSL https://lorislab.fr/sensor/404-sensor-linux-amd64 \
    -o 404-sensor
$ chmod +x 404-sensor

# Linux ARM64 (Raspberry Pi 4/5, ARM servers)
$ curl -fsSL https://lorislab.fr/sensor/404-sensor-linux-arm64 \
    -o 404-sensor
$ chmod +x 404-sensor

# Docker (Alpine-based, ~16 MB)
$ docker run -d \
  --name 404-sensor \
  --net=host \
  --restart=unless-stopped \
  lorislab/404-sensor

# macOS (Apple Silicon)
$ curl -fsSL https://lorislab.fr/sensor/404-sensor-darwin-arm64 \
    -o 404-sensor
$ chmod +x 404-sensor

2

Start

Launch the sensor in listen mode. It will print a QR code and pairing code.

$ ./404-sensor run --listen --port 40404

404 Sensor v1.0.0

────────────────────────

Listening on 0.0.0.0:40404

Web dashboard: http://192.168.1.42:4040

Pairing QR code:

███████ █ ███████

█ █ █ █

█ ███ █ █ ████ █

███████ █ ███████

Pairing code: AX7K-9M2P

Waiting for app connection…

3

Pair

Open the 404 app and connect to your new sensor.

Open the 404 app on iPhone or Mac
Go to Collab tab → tap Connect
Scan the QR code, or enter IP + port + pairing code manually
Done — sensor is live and monitoring

Point your iPhone camera at the QR code in the terminal to auto-fill the IP, port, and pairing code. No manual entry needed.

Advanced Configuration

Options & flags

Flag	Default	Description
`--port`	`40404`	TCP port the sensor listens on for app connections.
`--dashboard-port`	`4040`	Port for the local web dashboard (read-only status page).
`--name`	hostname	Display name shown in the 404 app sensor list.
`--nvd-key`	—	NVD API key for CVE database sync (higher rate limits, recommended for production).
`--interval`	`60s`	Autonomous monitoring check interval (ping, uptime, memory).
`--no-dashboard`	—	Disable the web dashboard entirely.

Systemd service (auto-start on boot)

# /etc/systemd/system/404-sensor.service
[Unit]
Description=404 Network Sensor
After=network-online.target
Wants=network-online.target
 
[Service]
ExecStart=/usr/local/bin/404-sensor run --listen --name my-server
Restart=on-failure
RestartSec=5
User=nobody
 
[Install]
WantedBy=multi-user.target

$ sudo systemctl enable --now 404-sensor

Docker Compose

services:
  sensor:
    image: lorislab/404-sensor:latest
    container_name: 404-sensor
    network_mode: host
    restart: unless-stopped
    environment:
      - SENSOR_NAME=my-homelab
      - NVD_API_KEY=your-key-here

Security

Secure by design

The sensor was built with a zero-trust philosophy. Every connection is verified, every byte is encrypted.

TLS 1.3 encryption
All traffic between the sensor and the 404 app is encrypted end-to-end. No plaintext ever leaves the sensor.
HMAC-SHA256 authentication
Challenge-response handshake on every connection. Connecting without the correct pairing key is rejected immediately.
Single-use pairing codes
Pairing codes are valid for one session only. Re-pairing generates a new code automatically.
No persistent data storage
The sensor does not store diagnostic results, credentials, or network data. Only the CVE cache is written to disk.

Requirements

What you need

Platform Linux x86-64, ARM64, ARMv7 — or macOS (Apple Silicon) — or Docker

Disk ~10 MB binary + CVE cache (up to ~50 MB)

RAM ~20 MB at idle, ~40 MB during active scanning

Network TCP port 40404 reachable from the 404 app (local or VPN)

404 App 404 Network v1.0+ on iOS or macOS with an active Pro subscription

404 Sensor