A minimal, memory-conscious AI agentic server & hardware management portal in Go — purpose-built for RAM-constrained devices like the Raspberry Pi Zero 2 W (415 MB RAM) and embedded Linux hardware benchmarks.

pibench-server is a lightweight, zero-CGO Go server suite designed for single-board computers (such as the Raspberry Pi Zero 2 W). Running heavy Node.js/Bun runtimes (opencode serve) on low-RAM devices consumes 100–300 MB RSS, frequently triggering Linux kernel Out-Of-Memory (OOM) panics.

pibench-server combines two purpose-built components into an ultra-low-memory stack running at ~10–15 MB RSS:

1. opencode-tiny/: Lightweight Go agent server powering the AI Chat & Tool Calling engine.
2. usb-server/: HTMX + Go web admin portal featuring the PiScope 60 FPS logic analyzer, GPIO Hardware Manager, WiFi Control, and Web Terminal.
3. m5-stick-c/: ESP32 hardware companion suite providing MicroPython firmware, automated flashing scripts (uv run flash_m5stickc.py), analog voltage sampling (G36 ADC1_CH0 0.0V–3.3V), and ST7735 color LCD status display rendering.

                    ┌──────────────────────────────────────────────┐
                    │               Browser Client                 │
                    └──────────────────────┬───────────────────────┘
                                           │ HTTP / WS / SSE
                                           ▼
                    ┌──────────────────────────────────────────────┐
                    │  usb-server (Go + HTMX Admin Portal :8080)   │
                    ├──────────────┬───────────────┬───────────────┤
                    │  PiScope     │  GPIO Control │  Web Terminal │
                    └──────┬───────┴───────┬───────┴───────────────┘
                           │               │ UART / G36 ADC
                           ▼               ▼
                    ┌──────────────┐ ┌─────────────────────────────┐
                    │opencode-tiny │ │ M5StickC (ESP32 Companion)  │
                    │  (:3457)     │ │ - G36 Analog Sampling       │
                    └──────┬───────┘ │ - ST7735 LCD Status Display │
                           │         └─────────────────────────────┘
                           ▼
                    ┌──────────────────────────────────────────────┐
                    │ OpenAI Gateway / Local LLM (OpenMind :5000)  │
                    └──────────────────────────────────────────────┘

• Ultra-Low Memory Footprint: Idles at ~10–15 MB RSS.
• Embedded Web UI: Single-binary packaging via go:embed.
• Built-in Agentic Tools:
  • bash: Shell execution with timeout safety.
  • read / write / edit: Line-buffered reading, atomic writing, and chunk patch editing.
  • gpio_control: AI pin status reading, digital I/O writing, PWM, and peripheral overlay toggling.
  • host_shell: Direct shell command execution on any connected host machine (Linux, macOS, Windows PowerShell/CMD, or FreeBSD/BSD) via Reverse SSH bridge (127.0.0.1:22222), allowing the AI to access live booted host PCs/workstations zero-config.
  • superuser_access: Elevated privilege authentication & password inbox.
• SQLite Persistence: Embedded pure Go database (modernc.org/sqlite).

• ⚡ PiScope Digital Logic Analyzer: 60 FPS HTML5 Canvas logic scope with timebase scaling, dual measurement cursors (Cursor A/B with real-time $\Delta t$ microsecond readout & frequency counter), I2C/UART protocol decoders, mouse wheel zooming, and VCD/CSV capture exports.
• 🛠️ Tools & Reverse SSH Host Bridge (/tools): Auto-detects reverse SSH tunnels, generates copyable 1-liner host connection commands for Linux, macOS, Windows (winget / PowerShell OpenSSH), and FreeBSD (pkg) (ssh -R 22222:localhost:22), manages public SSH keys, and provides host connection installation helpers.
• 🔌 Active Hardware Peripheral Control: Detects and toggles SPI, I2C, UART Serial, 1-Wire, Hardware Shutdown Button, Fan Control, PWM Audio, and USB Gadget overlays (raspi-config nonint).
• 📶 WiFi & Web Terminal: Interactive web terminal shell (PTY websocket) and network manager.

Copy .env.example to create your local .env configuration file:

cp .env.example .env

Configure your gateway URL in .env:

OPENCODE_TINY_PORT=3457
OPENCODE_TINY_HOST=127.0.0.1
USB_SERVER_PORT=8080
OPENMIND_BASE_URL=http://pibox.local:5000/v1

# Build opencode-tiny
cd opencode-tiny && go build -o opencode-tiny . && cd ..

# Build usb-server
cd usb-server && go build -o usb-server . && cd ..

Always cross-compile on your host development machine to save device RAM:

# Build opencode-tiny for ARM64
cd opencode-tiny && GOOS=linux GOARCH=arm64 go build -o opencode-tiny-arm64 . && cd ..

# Build usb-server for ARM64
cd usb-server && GOOS=linux GOARCH=arm64 go build -o usb-server-arm64 . && cd ..

Deploy compiled binaries to your device:

scp opencode-tiny/opencode-tiny-arm64 <user>@<host_ip>:/tmp/ot-new
scp usb-server/usb-server-arm64 <user>@<host_ip>:/tmp/us-new
ssh <user>@<host_ip> "mv -f /tmp/ot-new /home/<user>/opencode-tiny && chmod +x /home/<user>/opencode-tiny && sudo systemctl restart opencode-tiny.service && mv -f /tmp/us-new /home/<user>/usb-server && chmod +x /home/<user>/usb-server && sudo systemctl restart usb-server.service"

Access the admin portal at http://<host>:8080/.

Create /etc/systemd/system/opencode-tiny.service:

[Unit]
Description=opencode-tiny agent server
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=<user>
WorkingDirectory=/home/<user>
Environment=OPENCODE_TINY_PORT=3457
ExecStart=/home/<user>/opencode-tiny
Restart=always
RestartSec=3
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target

Create /etc/systemd/system/usb-server.service:

[Unit]
Description=usb-server admin portal (Go + HTMX)
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=<user>
WorkingDirectory=/home/<user>/usb-server
ExecStart=/home/<user>/usb-server/usb-server
Restart=always
RestartSec=3
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target

Enable and start both daemons:

sudo systemctl daemon-reload
sudo systemctl enable --now opencode-tiny.service usb-server.service

Distributed under the MIT License. © 2026 bdragoncore.
Based on OpenCode (MIT License).