chore(agent): fix clippy needless_return for non-linux process collection

display welcome message on first run when a profile file is not created and remote server not specified.

.githooks/pre-commit

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+echo "[pre-commit] Running cargo fmt --all" >&2
+
+if ! command -v cargo >/dev/null 2>&1; then
+  echo "[pre-commit] cargo not found in PATH" >&2
+  exit 1
+fi
+
+cargo fmt --all
+
+# Stage any Rust files that were reformatted
+changed=$(git diff --name-only --diff-filter=M | grep -E '\\.rs$' || true)
+if [ -n "$changed" ]; then
+  echo "$changed" | xargs git add
+  echo "[pre-commit] Added formatted files" >&2
+fi
+
+# Fail if further diffs remain (shouldn't happen normally)
+unfmt=$(git diff --name-only --diff-filter=M | grep -E '\\.rs$' || true)
+if [ -n "$unfmt" ]; then
+  echo "[pre-commit] Some Rust files still differ after formatting:" >&2
+  echo "$unfmt" >&2
+  exit 1
+fi
+
+exit 0

.github/workflows/ci.yml

@@ -2,18 +2,128 @@ name: CI
 on:
   push:
   pull_request:
+
 jobs:
   build:
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest]
-    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy, rustfmt
+      - name: Install system dependencies (Linux)
+        if: matrix.os == 'ubuntu-latest'
+        run: sudo apt-get update && sudo apt-get install -y libdrm-dev libdrm-amdgpu1
       - name: Cargo fmt
         run: cargo fmt --all -- --check
       - name: Clippy
-        run: cargo clippy --all-targets --all-features -D warnings
-      - name: Build
-        run: cargo build --release --workspace
+        run: cargo clippy --all-targets --all-features -- -D warnings
+      - name: Build (release)
+        run: cargo build --release --workspace
+
+      - name: "Linux: start agent and run WS probe"
+        if: matrix.os == 'ubuntu-latest'
+        shell: bash
+        run: |
+          set -euo pipefail
+          RUST_LOG=info SOCKTOP_ENABLE_SSL=0 SOCKTOP_AGENT_GPU=0 SOCKTOP_AGENT_TEMP=0 ./target/release/socktop_agent -p 3000 > agent.log 2>&1 &
+          AGENT_PID=$!
+          for i in {1..60}; do
+            if curl -fsS http://127.0.0.1:3000/healthz >/dev/null; then break; fi
+            sleep 1
+          done
+          if ! curl -fsS http://127.0.0.1:3000/healthz >/dev/null; then
+            echo "--- agent.log (tail) ---"
+            tail -n 200 agent.log || true
+            (command -v ss >/dev/null && ss -ltnp || netstat -ltnp) || true
+            kill $AGENT_PID || true
+            exit 1
+          fi
+          SOCKTOP_WS=ws://127.0.0.1:3000/ws cargo test -p socktop --test ws_probe -- --nocapture
+          kill $AGENT_PID || true
+
+      - name: "Windows: start agent and run WS probe"
+        if: matrix.os == 'windows-latest'
+        shell: pwsh
+        run: |
+          $env:SOCKTOP_ENABLE_SSL = "0"
+          $env:SOCKTOP_AGENT_GPU = "0"
+          $env:SOCKTOP_AGENT_TEMP = "0"
+          $out = Join-Path $PWD "agent.out.txt"
+          $err = Join-Path $PWD "agent.err.txt"
+          $p = Start-Process -FilePath "${PWD}\target\release\socktop_agent.exe" -ArgumentList "-p 3000" -RedirectStandardOutput $out -RedirectStandardError $err -PassThru -NoNewWindow
+          $ready = $false
+          for ($i = 0; $i -lt 60; $i++) {
+            $pinfo = New-Object System.Diagnostics.ProcessStartInfo
+            $pinfo.FileName = "curl.exe"
+            $pinfo.Arguments = "-fsS http://127.0.0.1:3000/healthz"
+            $pinfo.RedirectStandardOutput = $true
+            $pinfo.RedirectStandardError = $true
+            $pinfo.UseShellExecute = $false
+            $proc = [System.Diagnostics.Process]::Start($pinfo)
+            $proc.WaitForExit()
+            if ($proc.ExitCode -eq 0) { $ready = $true; break }
+            Start-Sleep -Seconds 1
+          }
+          if (-not $ready) {
+            Write-Warning "TCP connect to (127.0.0.1 : 3000) failed"
+            if (Test-Path $out) { Write-Host "--- agent.out (full) ---"; Get-Content $out }
+            if (Test-Path $err) { Write-Host "--- agent.err (full) ---"; Get-Content $err }
+            Write-Host "--- netstat ---"
+            netstat -ano | Select-String ":3000" | ForEach-Object { $_.Line }
+            if ($p -and !$p.HasExited) { Stop-Process -Id $p.Id -Force -ErrorAction SilentlyContinue }
+            throw "agent did not become ready"
+          }
+          $env:SOCKTOP_WS = "ws://127.0.0.1:3000/ws"
+          try {
+            cargo test -p socktop --test ws_probe -- --nocapture
+          } finally {
+            if ($p -and !$p.HasExited) { Stop-Process -Id $p.Id -Force -ErrorAction SilentlyContinue }
+          }
+
+      - name: Smoke test (client --help)
+        run: cargo run -p socktop -- --help
+
+      - name: Package artifacts (Linux)
+        if: matrix.os == 'ubuntu-latest'
+        shell: bash
+        run: |
+          set -e
+          mkdir -p dist
+          cp target/release/socktop dist/
+          cp target/release/socktop_agent dist/
+          tar czf socktop-${{ matrix.os }}.tar.gz -C dist .
+
+      - name: Package artifacts (Windows)
+        if: matrix.os == 'windows-latest'
+        shell: pwsh
+        run: |
+          New-Item -ItemType Directory -Force -Path dist | Out-Null
+          Copy-Item target\release\socktop.exe dist\
+          Copy-Item target\release\socktop_agent.exe dist\
+          Compress-Archive -Path dist\* -DestinationPath socktop-${{ matrix.os }}.zip -Force
+
+      - name: Upload build artifacts (ephemeral)
+        uses: actions/upload-artifact@v4
+        with:
+          name: socktop-${{ matrix.os }}
+          path: |
+            *.tar.gz
+            *.zip
+
+      - name: Upload to rolling GitHub Release (main only)
+        if: github.ref == 'refs/heads/main' && github.event_name == 'push'
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: latest
+          name: Latest build
+          prerelease: true
+          draft: false
+          files: |
+            *.tar.gz
+            *.zip
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -1 +1,2 @@
 /target
+.vscode/

Cargo.toml

@@ -1,4 +1,5 @@
 [workspace]
+resolver = "2"
 members = [
     "socktop",
     "socktop_agent"
@@ -7,29 +8,36 @@ members = [
 [workspace.dependencies]
 # async + streams
 tokio = { version = "1", features = ["full"] }
-futures = "0.3"
 futures-util = "0.3"
 anyhow = "1.0"
 
 # websocket
-tokio-tungstenite = "0.24"
-tungstenite = "0.24"
+tokio-tungstenite = { version = "0.24", features = ["__rustls-tls", "connect"] }
 url = "2.5"
 
 # JSON + error handling
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-thiserror = "1.0"
 
-# system stats
-sysinfo = "0.32"
+# system stats (align across crates)
+sysinfo = "0.37"
 
 # CLI UI
 ratatui = "0.28"
 crossterm = "0.27"
 
-# date/time
-chrono = { version = "0.4", features = ["serde"] }
 
 # web server (remote-agent)
 axum = { version = "0.7", features = ["ws"] }
+
+# protobuf
+prost = "0.13"
+dirs-next = "2"
+
+[profile.release]
+# Favor smaller, simpler binaries with good runtime perf
+lto = "thin"
+codegen-units = 1
+panic = "abort"
+opt-level = 3
+strip = "symbols"

README.md

@@ -1,201 +1,378 @@
 # socktop
 
-**socktop** is a remote system monitor with a rich TUI interface, inspired by `top` and `btop`, that communicates with a lightweight remote agent over WebSockets.
+socktop is a remote system monitor with a rich TUI, inspired by top/btop, talking to a lightweight agent over WebSockets.
 
-It lets you watch CPU, memory, disks, network, temperatures, and processes on another machine in real-time — from the comfort of your terminal.
+- Linux agent: near-zero CPU when idle (request-driven, no always-on sampler)
+- TUI: smooth graphs, sortable process table, scrollbars, readable colors
 
-![socktop screenshot](./docs/socktop-screenshot.png)
+![socktop screenshot](./docs/14900ks_arch_alacritty_gpu_active_v2.jpg)
 
 ---
 
 ## Features
 
-- 📡 **Remote monitoring** via WebSocket — lightweight agent sends JSON metrics
-- 🖥 **Rich TUI** built with [ratatui](https://github.com/ratatui-org/ratatui)
-- 🔍 **Detailed CPU view** — per-core history, current load, and trends
-- 📊 **Memory, Swap, Disk usage** — human-readable units, color-coded
-- 🌡 **Temperatures** — CPU temperature with visual indicators
-- 📈 **Network throughput** — live sparkline graphs with peak tracking
-- 🏷 **Top processes table** — PID, name, CPU%, memory, and memory%
-- 🎨 Color-coded load, zebra striping for readability
-- ⌨ **Keyboard shortcuts**:
-  - `q` / `Esc` → Quit
+- Remote monitoring via WebSocket (JSON over WS)
+- Optional WSS (TLS): agent auto‑generates a self‑signed cert on first run; client pins the cert via --tls-ca/-t 
+- TUI built with ratatui
+- CPU
+  - Overall sparkline + per-core mini bars
+  - Accurate per-process CPU% (Linux /proc deltas), normalized to 0–100%
+- Memory/Swap gauges with human units
+- Disks: per-device usage
+- Network: per-interface throughput with sparklines and peak markers
+- Temperatures: CPU (optional)
+- Top processes (top 50)
+  - PID, name, CPU%, memory, and memory%
+  - Click-to-sort by CPU% or Mem (descending)
+  - Scrollbar and mouse/keyboard scrolling
+  - Total process count shown in the header
+  - Only top-level processes listed (threads hidden) — matches btop/top
+- Optional GPU metrics (can be disabled)
+- Optional auth token for the agent
+
+---
+
+## Prerequisites: Install Rust (rustup)
+
+Rust is fast, safe, and cross‑platform. Installing it will make your machine better. Consider yourself privileged.
+
+Linux/macOS:
+```bash
+curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
+# load cargo for this shell
+source "$HOME/.cargo/env"
+# ensure stable is up to date
+rustup update stable
+rustc --version
+cargo --version
+# after install you may need to reload your shell, e.g.:
+exec bash   # or: exec zsh / exec fish
+```
+
+Windows (for the brave): install from https://rustup.rs with the MSVC toolchain. Yes, you’ll need Visual Studio Build Tools. You chose Windows — enjoy the ride.
+
+### Raspberry Pi / Ubuntu / PopOS (required)
+
+Install GPU support with apt command below
+
+```bash
+sudo apt-get update
+sudo apt-get install libdrm-dev libdrm-amdgpu1
+```
 
 ---
 
 ## Architecture
 
-`socktop` has **two components**:
+Two components:
 
-1. **Agent** (remote side)  
-   A small Rust WebSocket server that runs on the target machine and gathers metrics via [sysinfo](https://crates.io/crates/sysinfo).
+1) Agent (remote): small Rust WS server using sysinfo + /proc. It collects metrics only when the client requests them over the WebSocket (request-driven). No background sampling loop.
 
-2. **Client** (local side)  
-   The TUI app (`socktop`) that connects to the agent’s `/ws` endpoint, receives JSON metrics, and renders them.
-
-The two communicate over a persistent WebSocket connection.
+2) Client (local): TUI that connects to ws://HOST:PORT/ws (or wss://HOST:PORT/ws when TLS is enabled) and renders updates.
 
 ---
 
-## Adaptive (idle-aware) sampling
+## Quick start
 
-The socktop agent now samples system metrics only when at least one WebSocket client is connected. When idle (no clients), the sampler sleeps and CPU usage drops to ~0%.
+- Build both binaries:
 
-How it works
-- The WebSocket handler increments/decrements a client counter in `AppState` on connect/disconnect.
-- A background sampler wakes when the counter transitions from 0 → >0 and sleeps when it returns to 0.
-- The most recent metrics snapshot is cached as JSON for fast responses.
-
-Cold start behavior
-- If a client requests metrics while the cache is empty (e.g., just started or after a long idle), the agent performs a one-off synchronous collection to respond immediately.
-
-Tuning
-- Sampling interval (active): update `spawn_sampler(state, Duration::from_millis(500))` in `socktop_agent/src/main.rs`.
-- Always-on or low-frequency idle sampling: replace the “sleep when idle” logic in `socktop_agent/src/sampler.rs` with a low-frequency interval. Example sketch:
-
-```rust
-// In sampler.rs (sketch): sample every 10s when idle, 500ms when active
-let idle_period = Duration::from_secs(10);
-loop {
-    let active = state.client_count.load(Ordering::Relaxed) > 0;
-    let period = if active { Duration::from_millis(500) } else { idle_period };
-    let mut ticker = tokio::time::interval(period);
-    ticker.tick().await;
-    if !active {
-        // wake early if a client connects
-        tokio::select! {
-            _ = ticker.tick() => {},
-            _ = state.wake_sampler.notified() => continue,
-        }
-    }
-    let m = collect_metrics(&state).await;
-    if let Ok(js) = serde_json::to_string(&m) {
-        *state.last_json.write().await = js;
-    }
-}
-```
-
----
-
-## Installation
-
-### Prerequisites
-- Rust 1.75+ (recommended latest stable)
-- Cargo package manager
-
-### Build from source
 ```bash
-git clone https://github.com/YOURNAME/socktop.git
+git clone https://github.com/jasonwitty/socktop.git
 cd socktop
 cargo build --release
 ```
 
-### Install as a cargo binary
+- Start the agent on the target machine (default port 3000):
+
 ```bash
-cargo install --path .
+./target/release/socktop_agent --port 3000
 ```
-This will install the `socktop` binary into `~/.cargo/bin`.
+
+- Connect with the TUI from your local machine:
+
+```bash
+./target/release/socktop ws://REMOTE_HOST:3000/ws
+```
+
+### Quick demo (no agent setup)
+
+Spin up a temporary local agent on port 3231 and connect automatically:
+
+```bash
+socktop --demo
+```
+
+Or just run `socktop` with no arguments and pick the built‑in `demo` entry from the interactive profile list (if you have saved profiles, `demo` is appended). The demo agent:
+
+- Runs locally (`ws://127.0.0.1:3231/ws`)
+- Stops automatically (you'll see "Stopped demo agent on port 3231") when you quit the TUI or press Ctrl-C
 
 ---
 
-## Running
+## Install (from crates.io)
 
-### 1. Start the agent on the remote machine
-The agent binary listens on a TCP port and serves `/ws`:
+You don’t need to clone this repo to use socktop. Install the published binaries with cargo:
 
 ```bash
-remote_agent 0.0.0.0:8080
+# TUI (client)
+cargo install socktop
+# Agent (server)
+cargo install socktop_agent
 ```
 
-> **Tip:** You can run the agent under `systemd`, inside a Docker container, or just in a tmux/screen session.
+This drops socktop and socktop_agent into ~/.cargo/bin (add it to PATH).
+
+Notes:
+- After installing Rust via rustup, reload your shell (e.g., exec bash) so cargo is on PATH.
+- Windows: you can also grab prebuilt EXEs from GitHub Actions artifacts if rustup scares you. It shouldn’t. Be brave.
+
+System-wide agent (Linux)
 
-### 2. Connect with the client
-From your local machine:
 ```bash
-socktop ws://REMOTE_HOST:8080/ws
+# If you installed with cargo, binaries are in ~/.cargo/bin
+sudo install -o root -g root -m 0755 "$HOME/.cargo/bin/socktop_agent" /usr/local/bin/socktop_agent
+
+# Install and enable the systemd service (example unit in docs/)
+sudo install -o root -g root -m 0644 docs/socktop-agent.service /etc/systemd/system/socktop-agent.service
+sudo systemctl daemon-reload
+sudo systemctl enable --now socktop-agent
 ```
 
-Example:
 ```bash
-socktop ws://192.168.1.50:8080/ws
+
+# Enable SSL
+
+# Stop service
+sudo systemctl stop socktop-agent
+
+# Edit service to append SSL option and port
+sudo micro /etc/systemd/system/socktop-agent.service
+
+--
+ExecStart=/usr/local/bin/socktop_agent --enableSSL --port 8443
+--
+
+# Reload
+sudo systemctl daemon-reload
+
+# Restart
+sudo systemctl start socktop-agent
+
+# check logs for certificate location
+sudo journalctl -u socktop-agent -f
+
+--
+Aug 22 22:25:26 rpi-master socktop_agent[2913998]: socktop_agent: generated self-signed TLS certificate at /var/lib/socktop/.config/socktop_agent/tls/cert.pem
+--
+
 ```
 
+
 ---
 
 ## Usage
 
-When connected, `socktop` displays:
+Agent (server):
 
-**Left column:**
-- **CPU avg graph** — sparkline of recent overall CPU usage
-- **Memory gauge** — total and used RAM
-- **Swap gauge** — total and used swap
-- **Disks** — usage per device (only devices with available space > 0)
-- **Network Download/Upload** — sparkline in KB/s, with current & peak values
+```bash
+socktop_agent --port 3000
+# or env: SOCKTOP_PORT=3000 socktop_agent
+# optional auth: SOCKTOP_TOKEN=changeme socktop_agent
+# enable TLS (self‑signed cert, default port 8443; you can also use -p):
+socktop_agent --enableSSL --port 8443
+```
 
-**Right column:**
-- **Per-core history & trends** — each core’s recent load, current %, and trend arrow
-- **Top processes table** — top 20 processes with PID, name, CPU%, memory usage, and memory%
+Client (TUI):
+
+```bash
+socktop ws://HOST:3000/ws
+# with token:
+socktop "ws://HOST:3000/ws?token=changeme"
+# TLS with pinned server certificate (recommended over the internet):
+socktop --tls-ca /path/to/cert.pem wss://HOST:8443/ws
+# (By default hostname/SAN verification is skipped for ease on home networks. To enforce it add --verify-hostname)
+socktop --verify-hostname --tls-ca /path/to/cert.pem wss://HOST:8443/ws
+# shorthand:
+socktop -t /path/to/cert.pem wss://HOST:8443/ws
+# Note: providing --tls-ca/-t automatically upgrades ws:// to wss:// if you forget
+```
+
+Intervals (client-driven):
+- Fast metrics: ~500 ms
+- Processes: ~2 s (top 50)
+- Disks: ~5 s
+
+The agent stays idle unless queried. When queried, it collects just what’s needed.
 
 ---
 
-## Configuring the agent port
+## Connection Profiles (Named)
 
-The agent listens on TCP port 3000 by default. You can override this via a CLI flag, a positional port argument, or an environment variable:
+You can save frequently used connection settings (URL + optional TLS CA path) under a short name and reuse them later.
 
-- CLI flag:
-  - socktop_agent --port 8080
-  - socktop_agent -p 8080
-- Positional:
-  - socktop_agent 8080
-- Environment variable:
-  - SOCKTOP_PORT=8080 socktop_agent
+Config file location:
 
-Help:
-- socktop_agent --help
+- Linux (XDG): `$XDG_CONFIG_HOME/socktop/profiles.json`
+- Fallback (when XDG not set): `~/.config/socktop/profiles.json`
 
-The TUI should point to ws://HOST:PORT/ws, e.g.:
-- cargo run -p socktop -- ws://127.0.0.1:8080/ws
+### Creating a profile
+
+First time you specify a new `--profile/-P` name together with a URL (and optional `--tls-ca`), it is saved automatically:
+
+```bash
+socktop --profile prod ws://prod-host:3000/ws
+# With TLS pinning:
+socktop --profile prod-tls --tls-ca /path/to/cert.pem wss://prod-host:8443/ws
+
+You can also set custom intervals (milliseconds):
+
+```bash
+socktop --profile prod --metrics-interval-ms 750 --processes-interval-ms 3000 ws://prod-host:3000/ws
+```
+```
+
+If a profile already exists you will be prompted before overwriting:
+
+```
+$ socktop --profile prod ws://new-host:3000/ws
+Overwrite existing profile 'prod'? [y/N]: y
+```
+
+To overwrite without an interactive prompt pass `--save`:
+
+```bash
+socktop --profile prod --save ws://new-host:3000/ws
+```
+
+### Using a saved profile
+
+Just pass the profile name (no URL needed):
+
+```bash
+socktop --profile prod
+socktop -P prod-tls      # short flag
+```
+
+The stored URL (and TLS CA path, if any) plus any saved intervals will be used. TLS auto-upgrade still applies if a CA path is stored alongside a ws:// URL.
+
+### Interactive selection (no args)
+
+If you run `socktop` with no arguments and at least one profile exists, you will be shown a numbered list to pick from:
+
+```
+$ socktop
+Select profile:
+  1. prod
+  2. prod-tls
+Enter number (or blank to abort): 2
+```
+
+Choosing a number starts the TUI with that profile. A built‑in `demo` option is always appended; selecting it launches a local agent on port 3231 (no TLS) and connects to `ws://127.0.0.1:3231/ws`. Pressing Enter on blank aborts without connecting.
+
+### JSON format
+
+An example `profiles.json` (pretty‑printed):
+
+```json
+{
+  "profiles": {
+    "prod": { "url": "ws://prod-host:3000/ws" },
+    "prod-tls": {
+      "url": "wss://prod-host:8443/ws",
+      "tls_ca": "/home/user/certs/prod-cert.pem",
+      "metrics_interval_ms": 500,
+      "processes_interval_ms": 2000
+    }
+  },
+  "version": 0
+}
+```
+
+Notes:
+- The `tls_ca` path is stored as given; if you move or rotate the certificate update the profile by re-running with `--profile NAME --save`.
+- Deleting a profile: edit the JSON file and remove the entry (TUI does not yet have an in-app delete command).
+- Profiles are client-side convenience only; they do not affect the agent.
+- Intervals: `metrics_interval_ms` controls the fast metrics poll (default 500 ms). `processes_interval_ms` controls process list polling (default 2000 ms). Values below 100 ms (metrics) or 200 ms (processes) are clamped.
 
 ---
 
-## Keyboard Shortcuts
+## Updating
 
-| Key         | Action     |
-|-------------|------------|
-| `q` or `Esc`| Quit       |
+Update the agent (systemd):
+
+```bash
+# on the server running the agent
+cargo install socktop_agent --force
+sudo systemctl stop socktop-agent
+sudo install -o root -g root -m 0755 "$HOME/.cargo/bin/socktop_agent" /usr/local/bin/socktop_agent
+# if you changed the unit file:
+# sudo install -o root -g root -m 0644 docs/socktop-agent.service /etc/systemd/system/socktop-agent.service
+# sudo systemctl daemon-reload
+sudo systemctl start socktop-agent
+sudo systemctl status socktop-agent --no-pager
+# logs:
+# journalctl -u socktop-agent -f
+```
+
+Update the TUI (client):
+```bash
+cargo install socktop --force
+socktop ws://HOST:3000/ws
+```
+
+Tip: If only the binary changed, restart is enough. If the unit file changed, run sudo systemctl daemon-reload.
 
 ---
 
-## Security (optional token)
-By default, the agent exposes metrics over an unauthenticated WebSocket. For untrusted networks, set an auth token and pass it in the client URL:
+## Configuration (agent)
 
-- Server:
-  - SOCKTOP_TOKEN=changeme socktop_agent --port 3000
-- Client:
-  - socktop ws://HOST:3000/ws?token=changeme
+- Port:
+  - Flag: --port 8080 or -p 8080
+  - Positional: socktop_agent 8080
+  - Env: SOCKTOP_PORT=8080
+- TLS (self‑signed):
+  - Enable: --enableSSL
+  - Default TLS port: 8443 (override with --port/-p)
+  - Certificate/Key location (created on first TLS run):
+    - Linux (XDG): $XDG_CONFIG_HOME/socktop_agent/tls/{cert.pem,key.pem} (defaults to ~/.config)
+    - The agent prints these paths on creation.
+  - You can set XDG_CONFIG_HOME before first run to control where certs are written.
+  - Additional SANs: set `SOCKTOP_AGENT_EXTRA_SANS` (comma‑separated) before first TLS start to include extra IPs/DNS names in the cert. Example:
+    ```bash
+    SOCKTOP_AGENT_EXTRA_SANS="192.168.1.101,myhost.internal" socktop_agent --enableSSL
+    ```
+    This prevents client errors like `NotValidForName` when connecting via an IP not present in the default cert SAN list.
+  - Expiry / rotation: the generated cert is valid for ~397 days from creation. If the agent fails to start with an "ExpiredCertificate" error (or your client reports expiry), simply delete the existing cert and key:
+    ```bash
+    rm ~/.config/socktop_agent/tls/cert.pem ~/.config/socktop_agent/tls/key.pem
+    # (adjust path if XDG_CONFIG_HOME is set or different user)
+    systemctl restart socktop-agent   # if running under systemd
+    ```
+    On next TLS start the agent will generate a fresh pair. Only distribute the new cert.pem to clients (never the key).
+- Auth token (optional): SOCKTOP_TOKEN=changeme
+- Disable GPU metrics: SOCKTOP_AGENT_GPU=0
+- Disable CPU temperature: SOCKTOP_AGENT_TEMP=0
 
 ---
 
-## Platform notes
-- Linux x86_64/AMD/Intel: fully supported.
-- Raspberry Pi:
-  - 64-bit: rustup target add aarch64-unknown-linux-gnu; build on-device for simplicity.
-  - 32-bit: rustup target add armv7-unknown-linux-gnueabihf.
-- Windows:
-  - TUI and agent build/run with stable Rust. Use PowerShell:
-    - cargo run -p socktop_agent -- --port 3000
-    - cargo run -p socktop -- ws://127.0.0.1:3000/ws
-  - CPU temperature may be unavailable; display will show N/A.
+## Keyboard & Mouse
+
+- Quit: q or Esc
+- Processes pane:
+  - Click “CPU %” to sort by CPU descending
+  - Click “Mem” to sort by memory descending
+  - Mouse wheel: scroll
+  - Drag scrollbar: scroll
+  - Arrow/PageUp/PageDown/Home/End: scroll
 
 ---
 
 ## Example agent JSON
-`socktop` expects the agent to send metrics in this shape:
+
 ```json
 {
   "cpu_total": 12.4,
-  "cpu_per_core": [11.2, 15.7, ...],
+  "cpu_per_core": [11.2, 15.7],
   "mem_total": 33554432,
   "mem_used": 18321408,
   "swap_total": 0,
@@ -207,42 +384,162 @@ By default, the agent exposes metrics over an unauthenticated WebSocket. For unt
   "networks": [{"name":"eth0","received":12345678,"transmitted":87654321}],
   "top_processes": [
     {"pid":1234,"name":"nginx","cpu_usage":1.2,"mem_bytes":12345678}
-  ]
+  ],
+  "gpus": null
 }
 ```
 
+Notes:
+- process_count is merged into the main metrics on the client when processes are polled.
+- top_processes are the current top 50 (sorting in the TUI is client-side).
+
+---
+
+## Security
+
+Set a token on the agent and pass it as a query param from the client:
+
+Server:
+
+```bash
+SOCKTOP_TOKEN=changeme socktop_agent --port 3000
+```
+
+Client:
+
+```bash
+socktop "ws://HOST:3000/ws?token=changeme"
+```
+
+### TLS / WSS
+
+For encrypted connections, enable TLS on the agent and pin the server certificate on the client.
+
+Server (generates self‑signed cert and key on first run):
+
+```bash
+socktop_agent --enableSSL --port 8443
+```
+
+Client (trust/pin the server cert; copy cert.pem from the agent):
+
+```bash
+socktop --tls-ca /path/to/agent/cert.pem wss://HOST:8443/ws
+```
+
+Notes:
+- Do not copy the private key off the server; only the cert.pem is needed by clients.
+- When --tls-ca/-t is supplied, the client auto‑upgrades ws:// to wss:// to avoid protocol mismatch.
+- Hostname (SAN) verification is DISABLED by default (the cert is still pinned). Use `--verify-hostname` to enable strict SAN checking.
+- You can run multiple clients with different cert paths by passing --tls-ca per invocation.
+
+---
+
+## Using tmux to monitor multiple hosts
+
+You can use tmux to show multiple socktop instances in a single terminal.
+
+![socktop screenshot](./docs/tmux_4_rpis_v3.jpg)
+monitoring 4 Raspberry Pis using Tmux
+
+Prerequisites:
+- Install tmux (Ubuntu/Debian: `sudo apt-get install tmux`)
+
+Key bindings (defaults):
+- Split left/right: Ctrl-b %
+- Split top/bottom: Ctrl-b "
+- Move between panes: Ctrl-b + Arrow keys
+- Show pane numbers: Ctrl-b q
+- Close a pane: Ctrl-b x
+- Detach from session: Ctrl-b d
+
+Two panes (left/right)
+- This creates a session named "socktop", splits it horizontally, and starts two socktops.
+
+```bash
+tmux new-session -d -s socktop 'socktop ws://HOST1:3000/ws' \; \
+  split-window -h 'socktop ws://HOST2:3000/ws' \; \
+  select-layout even-horizontal \; \
+  attach
+```
+
+Four panes (top-left, top-right, bottom-left, bottom-right)
+- This creates a 2x2 grid with one socktop per pane.
+
+```bash
+tmux new-session -d -s socktop 'socktop ws://HOST1:3000/ws' \; \
+  split-window -h 'socktop ws://HOST2:3000/ws' \; \
+  select-pane -t 0 \; split-window -v 'socktop ws://HOST3:3000/ws' \; \
+  select-pane -t 1 \; split-window -v 'socktop ws://HOST4:3000/ws' \; \
+  select-layout tiled \; \
+  attach
+```
+
+Tips:
+- Replace HOST1..HOST4 (and ports) with your targets.
+- Reattach later: `tmux attach -t socktop`
+
+---
+
+## Platform notes
+
+- Linux: fully supported (agent and client).
+- Raspberry Pi:
+  - 64-bit: aarch64-unknown-linux-gnu
+  - 32-bit: armv7-unknown-linux-gnueabihf
+- Windows:
+  - TUI + agent can build with stable Rust; bring your own MSVC. You’re on Windows; you know the drill.
+  - CPU temperature may be unavailable.
+  - binary exe for both available in build artifacts under actions.
+- macOS:
+  - TUI works; agent is primarily targeted at Linux. Agent will run just fine on macos for debugging but I have not documented how to run as a service, I may not given the "security" feautures with applications on macos. We will see. 
+
 ---
 
 ## Development
 
-### Run in debug mode:
-```bash
-cargo run -- ws://127.0.0.1:8080/ws
-```
-
-### Code formatting & lint:
 ```bash
 cargo fmt
-cargo clippy
+cargo clippy --all-targets --all-features
+cargo run -p socktop -- ws://127.0.0.1:3000/ws
+# TLS (dev): first run will create certs under ~/.config/socktop_agent/tls/
+cargo run -p socktop_agent -- --enableSSL --port 8443
 ```
 
+### Auto-format on commit
+
+A sample pre-commit hook that runs `cargo fmt --all` is provided in `.githooks/pre-commit`.
+Enable it (one-time):
+
+```bash
+git config core.hooksPath .githooks
+chmod +x .githooks/pre-commit
+```
+
+Every commit will then format Rust sources and restage them automatically.
+
 ---
 
 ## Roadmap
-- [ ] Configurable refresh interval
-- [ ] Filter/sort top processes in the TUI
+
+- [x] Agent authentication (token)
+- [x] Hide per-thread entries; only show processes
+- [x] Sort top processes in the TUI
+- [ ] Configurable refresh intervals (client)
 - [ ] Export metrics to file
-- [ ] TLS / WSS support
-- [ ] Agent authentication
+- [x] TLS / WSS support (self‑signed server cert + client pinning)
+- [x] Split processes/disks to separate WS calls with independent cadences (already logical on client; formalize API)
 
 ---
 
 ## License
-MIT License — see [LICENSE](LICENSE).
+
+MIT — see LICENSE.
 
 ---
 
 ## Acknowledgements
-- [`ratatui`](https://github.com/ratatui-org/ratatui) for terminal UI rendering
-- [`sysinfo`](https://crates.io/crates/sysinfo) for system metrics
-- [`tokio-tungstenite`](https://crates.io/crates/tokio-tungstenite) for WebSocket client/server
+
+- ratatui for the TUI
+- sysinfo for system metrics
+- tokio-tungstenite for WebSockets

nohup.out

@@ -0,0 +1,8 @@
+socktop_agent: TLS enabled. Listening on wss://0.0.0.0:8433/ws
+socktop_agent: TLS enabled. Listening on wss://0.0.0.0:8433/ws
+socktop_agent: TLS enabled. Listening on wss://0.0.0.0:8433/ws
+Error: Address already in use (os error 98)
+socktop_agent: TLS enabled. Listening on wss://0.0.0.0:8433/ws
+Error: Address already in use (os error 98)
+socktop_agent: TLS enabled. Listening on wss://0.0.0.0:8443/ws
+socktop_agent: TLS enabled. Listening on wss://0.0.0.0:8443/ws

proto/processes.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+package socktop;
+
+// All running processes. Sorting is done client-side.
+message Processes {
+  uint64 process_count = 1;           // total processes in the system
+  repeated Process rows = 2;          // all processes
+}
+
+message Process {
+  uint32 pid = 1;
+  string name = 2;
+  float cpu_usage = 3;                // 0..100
+  uint64 mem_bytes = 4;               // RSS bytes
+}

rust-toolchain.toml

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "stable"
+components = ["clippy", "rustfmt"]

socktop/Cargo.toml

@@ -1,20 +1,32 @@
 [package]
 name = "socktop"
-version = "0.1.0"
+version = "0.1.3"
 authors = ["Jason Witty <jasonpwitty+socktop@proton.me>"]
 description = "Remote system monitor over WebSocket, TUI like top"
 edition = "2021"
+license = "MIT"
 
 [dependencies]
 tokio = { workspace = true }
 tokio-tungstenite = { workspace = true }
-tungstenite = { workspace = true }
-futures = { workspace = true }
 futures-util = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 url = { workspace = true }
 ratatui = { workspace = true }
 crossterm = { workspace = true }
-chrono = { workspace = true }
 anyhow = { workspace = true }
+flate2 = { version = "1", default-features = false, features = ["rust_backend"] }
+dirs-next = { workspace = true }
+sysinfo = { workspace = true }
+rustls = "0.23"
+rustls-pemfile = "2.1"
+prost = { workspace = true }
+
+[dev-dependencies]
+assert_cmd = "2.0"
+tempfile = "3"
+
+[build-dependencies]
+prost-build = "0.13"
+protoc-bin-vendored = "3"

socktop/build.rs

@@ -0,0 +1,14 @@
+fn main() {
+    // Vendored protoc for reproducible builds (works on crates.io build machines)
+    let protoc = protoc_bin_vendored::protoc_bin_path().expect("protoc");
+    std::env::set_var("PROTOC", &protoc);
+
+    // Tell Cargo when to re-run
+    println!("cargo:rerun-if-changed=proto/processes.proto");
+
+    let mut cfg = prost_build::Config::new();
+    cfg.out_dir(std::env::var("OUT_DIR").unwrap());
+    // Use in-crate relative path so `cargo package` includes the file
+    cfg.compile_protos(&["proto/processes.proto"], &["proto"]) // paths relative to CARGO_MANIFEST_DIR
+        .expect("compile protos");
+}

socktop/proto/processes.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+package socktop;
+
+// All running processes. Sorting is done client-side.
+message Processes {
+  uint64 process_count = 1;           // total processes in the system
+  repeated Process rows = 2;          // all processes
+}
+
+message Process {
+  uint32 pid = 1;
+  string name = 2;
+  float cpu_usage = 3;                // 0..100
+  uint64 mem_bytes = 4;               // RSS bytes
+}

socktop/src/app.rs

@@ -1,23 +1,36 @@
 //! App state and main loop: input handling, fetching metrics, updating history, and drawing.
 
-use std::{collections::VecDeque, io, time::{Duration, Instant}};
+use std::{
+    collections::VecDeque,
+    io,
+    time::{Duration, Instant},
+};
 
 use crossterm::{
-    event::{self, Event, KeyCode},
+    event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode},
     execute,
     terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
 };
 use ratatui::{
     backend::CrosstermBackend,
-    layout::{Constraint, Direction},
+    layout::{Constraint, Direction, Rect},
+    //style::Color, // + add Color
     Terminal,
 };
 use tokio::time::sleep;
 
 use crate::history::{push_capped, PerCoreHistory};
 use crate::types::Metrics;
-use crate::ui::{header::draw_header, cpu::{draw_cpu_avg_graph, draw_per_core_bars}, mem::draw_mem, swap::draw_swap, disks::draw_disks, net::draw_net_spark, processes::draw_top_processes};
-use crate::ws::{connect, request_metrics};
+use crate::ui::cpu::{
+    draw_cpu_avg_graph, draw_per_core_bars, per_core_clamp, per_core_content_area,
+    per_core_handle_key, per_core_handle_mouse, per_core_handle_scrollbar_mouse, PerCoreScrollDrag,
+};
+use crate::ui::processes::{processes_handle_key, processes_handle_mouse, ProcSortBy};
+use crate::ui::{
+    disks::draw_disks, gpu::draw_gpu, header::draw_header, mem::draw_mem, net::draw_net_spark,
+    swap::draw_swap,
+};
+use crate::ws::{connect, request_disks, request_metrics, request_processes};
 
 pub struct App {
     // Latest metrics + histories
@@ -38,6 +51,25 @@ pub struct App {
 
     // Quit flag
     should_quit: bool,
+
+    pub per_core_scroll: usize,
+    pub per_core_drag: Option<PerCoreScrollDrag>, // new: drag state
+    pub procs_scroll_offset: usize,
+    pub procs_drag: Option<PerCoreScrollDrag>,
+    pub procs_sort_by: ProcSortBy,
+    last_procs_area: Option<ratatui::layout::Rect>,
+
+    last_procs_poll: Instant,
+    last_disks_poll: Instant,
+    procs_interval: Duration,
+    disks_interval: Duration,
+    metrics_interval: Duration,
+
+    // For reconnects
+    ws_url: String,
+    // Security / status flags
+    pub is_tls: bool,
+    pub has_token: bool,
 }
 
 impl App {
@@ -52,17 +84,57 @@ impl App {
             rx_peak: 0,
             tx_peak: 0,
             should_quit: false,
+            per_core_scroll: 0,
+            per_core_drag: None,
+            procs_scroll_offset: 0,
+            procs_drag: None,
+            procs_sort_by: ProcSortBy::CpuDesc,
+            last_procs_area: None,
+            last_procs_poll: Instant::now()
+                .checked_sub(Duration::from_secs(2))
+                .unwrap_or_else(Instant::now), // trigger immediately on first loop
+            last_disks_poll: Instant::now()
+                .checked_sub(Duration::from_secs(5))
+                .unwrap_or_else(Instant::now),
+            procs_interval: Duration::from_secs(2),
+            disks_interval: Duration::from_secs(5),
+            metrics_interval: Duration::from_millis(500),
+            ws_url: String::new(),
+            is_tls: false,
+            has_token: false,
         }
     }
 
-    pub async fn run(&mut self, url: &str) -> Result<(), Box<dyn std::error::Error>> {
+    pub fn with_intervals(mut self, metrics_ms: Option<u64>, procs_ms: Option<u64>) -> Self {
+        if let Some(m) = metrics_ms {
+            self.metrics_interval = Duration::from_millis(m.max(100));
+        }
+        if let Some(p) = procs_ms {
+            self.procs_interval = Duration::from_millis(p.max(200));
+        }
+        self
+    }
+
+    pub fn with_status(mut self, is_tls: bool, has_token: bool) -> Self {
+        self.is_tls = is_tls;
+        self.has_token = has_token;
+        self
+    }
+
+    pub async fn run(
+        &mut self,
+        url: &str,
+        tls_ca: Option<&str>,
+    ) -> Result<(), Box<dyn std::error::Error>> {
         // Connect to agent
-        let mut ws = connect(url).await?;
+        //let mut ws = connect(url, tls_ca).await?;
+        self.ws_url = url.to_string();
+        let mut ws = connect(url, tls_ca).await?;
 
         // Terminal setup
         enable_raw_mode()?;
         let mut stdout = io::stdout();
-        execute!(stdout, EnterAlternateScreen)?;
+        execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
         let backend = CrosstermBackend::new(stdout);
         let mut terminal = Terminal::new(backend)?;
         terminal.clear()?;
@@ -73,7 +145,7 @@ impl App {
         // Teardown
         disable_raw_mode()?;
         let backend = terminal.backend_mut();
-        execute!(backend, LeaveAlternateScreen)?;
+        execute!(backend, DisableMouseCapture, LeaveAlternateScreen)?;
         terminal.show_cursor()?;
 
         res
@@ -87,10 +159,118 @@ impl App {
         loop {
             // Input (non-blocking)
             while event::poll(Duration::from_millis(10))? {
-                if let Event::Key(k) = event::read()? {
-                    if matches!(k.code, KeyCode::Char('q') | KeyCode::Char('Q') | KeyCode::Esc) {
-                        self.should_quit = true;
+                match event::read()? {
+                    Event::Key(k) => {
+                        if matches!(
+                            k.code,
+                            KeyCode::Char('q') | KeyCode::Char('Q') | KeyCode::Esc
+                        ) {
+                            self.should_quit = true;
+                        }
+                        // Per-core scroll via keys (Up/Down/PageUp/PageDown/Home/End)
+                        let sz = terminal.size()?;
+                        let area = Rect::new(0, 0, sz.width, sz.height);
+                        let rows = ratatui::layout::Layout::default()
+                            .direction(Direction::Vertical)
+                            .constraints([
+                                Constraint::Length(1),
+                                Constraint::Ratio(1, 3),
+                                Constraint::Length(3),
+                                Constraint::Length(3),
+                                Constraint::Min(10),
+                            ])
+                            .split(area);
+                        let top = ratatui::layout::Layout::default()
+                            .direction(Direction::Horizontal)
+                            .constraints([Constraint::Percentage(66), Constraint::Percentage(34)])
+                            .split(rows[1]);
+                        let content = per_core_content_area(top[1]);
+
+                        per_core_handle_key(&mut self.per_core_scroll, k, content.height as usize);
+
+                        let total_rows = self
+                            .last_metrics
+                            .as_ref()
+                            .map(|mm| mm.cpu_per_core.len())
+                            .unwrap_or(0);
+                        per_core_clamp(
+                            &mut self.per_core_scroll,
+                            total_rows,
+                            content.height as usize,
+                        );
+
+                        if let Some(p_area) = self.last_procs_area {
+                            // page size = visible rows (inner height minus header = 1)
+                            let page = p_area.height.saturating_sub(3).max(1) as usize; // borders (2) + header (1)
+                            processes_handle_key(&mut self.procs_scroll_offset, k, page);
+                        }
                     }
+                    Event::Mouse(m) => {
+                        // Layout to get areas
+                        let sz = terminal.size()?;
+                        let area = Rect::new(0, 0, sz.width, sz.height);
+                        let rows = ratatui::layout::Layout::default()
+                            .direction(Direction::Vertical)
+                            .constraints([
+                                Constraint::Length(1),
+                                Constraint::Ratio(1, 3),
+                                Constraint::Length(3),
+                                Constraint::Length(3),
+                                Constraint::Min(10),
+                            ])
+                            .split(area);
+                        let top = ratatui::layout::Layout::default()
+                            .direction(Direction::Horizontal)
+                            .constraints([Constraint::Percentage(66), Constraint::Percentage(34)])
+                            .split(rows[1]);
+
+                        // Content wheel scrolling
+                        let content = per_core_content_area(top[1]);
+                        per_core_handle_mouse(
+                            &mut self.per_core_scroll,
+                            m,
+                            content,
+                            content.height as usize,
+                        );
+
+                        // Scrollbar clicks/drag
+                        let total_rows = self
+                            .last_metrics
+                            .as_ref()
+                            .map(|mm| mm.cpu_per_core.len())
+                            .unwrap_or(0);
+                        per_core_handle_scrollbar_mouse(
+                            &mut self.per_core_scroll,
+                            &mut self.per_core_drag,
+                            m,
+                            top[1],
+                            total_rows,
+                        );
+
+                        // Clamp to bounds
+                        per_core_clamp(
+                            &mut self.per_core_scroll,
+                            total_rows,
+                            content.height as usize,
+                        );
+
+                        // Processes table: sort by column on header click
+                        if let (Some(mm), Some(p_area)) =
+                            (self.last_metrics.as_ref(), self.last_procs_area)
+                        {
+                            if let Some(new_sort) = processes_handle_mouse(
+                                &mut self.procs_scroll_offset,
+                                &mut self.procs_drag,
+                                m,
+                                p_area,
+                                mm.top_processes.len(),
+                            ) {
+                                self.procs_sort_by = new_sort;
+                            }
+                        }
+                    }
+                    Event::Resize(_, _) => {}
+                    _ => {}
                 }
             }
             if self.should_quit {
@@ -100,19 +280,54 @@ impl App {
             // Fetch and update
             if let Some(m) = request_metrics(ws).await {
                 self.update_with_metrics(m);
+
+                // Only poll processes every 2s
+                if self.last_procs_poll.elapsed() >= self.procs_interval {
+                    if let Some(procs) = request_processes(ws).await {
+                        if let Some(mm) = self.last_metrics.as_mut() {
+                            mm.top_processes = procs.top_processes;
+                            mm.process_count = Some(procs.process_count);
+                        }
+                    }
+                    self.last_procs_poll = Instant::now();
+                }
+
+                // Only poll disks every 5s
+                if self.last_disks_poll.elapsed() >= self.disks_interval {
+                    if let Some(disks) = request_disks(ws).await {
+                        if let Some(mm) = self.last_metrics.as_mut() {
+                            mm.disks = disks;
+                        }
+                    }
+                    self.last_disks_poll = Instant::now();
+                }
             }
 
             // Draw
             terminal.draw(|f| self.draw(f))?;
 
             // Tick rate
-            sleep(Duration::from_millis(500)).await;
+            sleep(self.metrics_interval).await;
         }
 
         Ok(())
     }
 
-    fn update_with_metrics(&mut self, m: Metrics) {
+    fn update_with_metrics(&mut self, mut m: Metrics) {
+        if let Some(prev) = &self.last_metrics {
+            // Preserve slower fields when the fast payload omits them
+            if m.disks.is_empty() {
+                m.disks = prev.disks.clone();
+            }
+            if m.top_processes.is_empty() {
+                m.top_processes = prev.top_processes.clone();
+            }
+            // Preserve total processes count across fast updates
+            if m.process_count.is_none() {
+                m.process_count = prev.process_count;
+            }
+        }
+
         // CPU avg history
         let v = m.cpu_total.clamp(0.0, 100.0).round() as u64;
         push_capped(&mut self.cpu_hist, v, 600);
@@ -130,69 +345,167 @@ impl App {
             let rx = ((rx_total.saturating_sub(prx)) as f64 / dt / 1024.0).round() as u64;
             let tx = ((tx_total.saturating_sub(ptx)) as f64 / dt / 1024.0).round() as u64;
             (rx, tx)
-        } else { (0, 0) };
+        } else {
+            (0, 0)
+        };
         self.last_net_totals = Some((rx_total, tx_total, now));
         push_capped(&mut self.rx_hist, rx_kb, 600);
         push_capped(&mut self.tx_hist, tx_kb, 600);
         self.rx_peak = self.rx_peak.max(rx_kb);
         self.tx_peak = self.tx_peak.max(tx_kb);
 
+        // Store merged snapshot
         self.last_metrics = Some(m);
     }
 
-    fn draw(&mut self, f: &mut ratatui::Frame<'_>) {
+    pub fn draw(&mut self, f: &mut ratatui::Frame<'_>) {
         let area = f.area();
 
+        // Root rows: header, top (cpu avg + per-core), memory, swap, bottom
         let rows = ratatui::layout::Layout::default()
             .direction(Direction::Vertical)
             .constraints([
-                Constraint::Length(1),
-                Constraint::Ratio(1, 3),
-                Constraint::Length(3),
-                Constraint::Length(3),
-                Constraint::Min(10),
+                Constraint::Length(1),   // header
+                Constraint::Ratio(1, 3), // top row
+                Constraint::Length(3),   // memory (left) + GPU (right, part 1)
+                Constraint::Length(3),   // swap (left)   + GPU (right, part 2)
+                Constraint::Min(10),     // bottom: disks + net (left), top procs (right)
             ])
             .split(area);
 
-        draw_header(f, rows[0], self.last_metrics.as_ref());
+        // Header
+        draw_header(
+            f,
+            rows[0],
+            self.last_metrics.as_ref(),
+            self.is_tls,
+            self.has_token,
+            self.metrics_interval,
+            self.procs_interval,
+        );
 
-        let top = ratatui::layout::Layout::default()
+        // Top row: left CPU avg, right Per-core (full top-right)
+        let top_lr = ratatui::layout::Layout::default()
             .direction(Direction::Horizontal)
             .constraints([Constraint::Percentage(66), Constraint::Percentage(34)])
             .split(rows[1]);
 
-        draw_cpu_avg_graph(f, top[0], &self.cpu_hist, self.last_metrics.as_ref());
-        draw_per_core_bars(f, top[1], self.last_metrics.as_ref(), &self.per_core_hist);
+        draw_cpu_avg_graph(f, top_lr[0], &self.cpu_hist, self.last_metrics.as_ref());
+        draw_per_core_bars(
+            f,
+            top_lr[1],
+            self.last_metrics.as_ref(),
+            &self.per_core_hist,
+            self.per_core_scroll,
+        );
 
-        draw_mem(f, rows[2], self.last_metrics.as_ref());
-        draw_swap(f, rows[3], self.last_metrics.as_ref());
-
-        let bottom = ratatui::layout::Layout::default()
+        // Memory + Swap rows split into left/right columns
+        let mem_lr = ratatui::layout::Layout::default()
             .direction(Direction::Horizontal)
             .constraints([Constraint::Percentage(66), Constraint::Percentage(34)])
+            .split(rows[2]);
+        let swap_lr = ratatui::layout::Layout::default()
+            .direction(Direction::Horizontal)
+            .constraints([Constraint::Percentage(66), Constraint::Percentage(34)])
+            .split(rows[3]);
+
+        // Left: Memory + Swap
+        draw_mem(f, mem_lr[0], self.last_metrics.as_ref());
+        draw_swap(f, swap_lr[0], self.last_metrics.as_ref());
+
+        // Right: GPU spans the same vertical space as Memory + Swap
+        let gpu_area = ratatui::layout::Rect {
+            x: mem_lr[1].x,
+            y: mem_lr[1].y,
+            width: mem_lr[1].width,
+            height: mem_lr[1].height + swap_lr[1].height,
+        };
+        draw_gpu(f, gpu_area, self.last_metrics.as_ref());
+
+        // Bottom area: left = Disks + Network, right = Top Processes
+        let bottom_lr = ratatui::layout::Layout::default()
+            .direction(Direction::Horizontal)
+            .constraints([Constraint::Percentage(60), Constraint::Percentage(40)])
             .split(rows[4]);
 
+        // Left bottom: Disks + Net stacked (make net panes slightly taller)
         let left_stack = ratatui::layout::Layout::default()
             .direction(Direction::Vertical)
-            .constraints([Constraint::Min(6), Constraint::Length(4), Constraint::Length(4)])
-            .split(bottom[0]);
+            .constraints([
+                Constraint::Min(4),    // Disks shrink slightly
+                Constraint::Length(5), // Download taller
+                Constraint::Length(5), // Upload taller
+            ])
+            .split(bottom_lr[0]);
 
         draw_disks(f, left_stack[0], self.last_metrics.as_ref());
         draw_net_spark(
             f,
             left_stack[1],
-            &format!("Download (KB/s) — now: {} | peak: {}", self.rx_hist.back().copied().unwrap_or(0), self.rx_peak),
+            &format!(
+                "Download (KB/s) — now: {} | peak: {}",
+                self.rx_hist.back().copied().unwrap_or(0),
+                self.rx_peak
+            ),
             &self.rx_hist,
             ratatui::style::Color::Green,
         );
         draw_net_spark(
             f,
             left_stack[2],
-            &format!("Upload (KB/s) — now: {} | peak: {}", self.tx_hist.back().copied().unwrap_or(0), self.tx_peak),
+            &format!(
+                "Upload (KB/s) — now: {} | peak: {}",
+                self.tx_hist.back().copied().unwrap_or(0),
+                self.tx_peak
+            ),
             &self.tx_hist,
             ratatui::style::Color::Blue,
         );
 
-        draw_top_processes(f, bottom[1], self.last_metrics.as_ref());
+        // Right bottom: Top Processes fills the column
+        let procs_area = bottom_lr[1];
+        // Cache for input handlers
+        self.last_procs_area = Some(procs_area);
+        crate::ui::processes::draw_top_processes(
+            f,
+            procs_area,
+            self.last_metrics.as_ref(),
+            self.procs_scroll_offset,
+            self.procs_sort_by,
+        );
     }
-}
+}
+
+impl Default for App {
+    fn default() -> Self {
+        Self {
+            last_metrics: None,
+            cpu_hist: VecDeque::with_capacity(600),
+            per_core_hist: PerCoreHistory::new(60),
+            last_net_totals: None,
+            rx_hist: VecDeque::with_capacity(600),
+            tx_hist: VecDeque::with_capacity(600),
+            rx_peak: 0,
+            tx_peak: 0,
+            should_quit: false,
+            per_core_scroll: 0,
+            per_core_drag: None,
+            procs_scroll_offset: 0,
+            procs_drag: None,
+            procs_sort_by: ProcSortBy::CpuDesc,
+            last_procs_area: None,
+            last_procs_poll: Instant::now()
+                .checked_sub(Duration::from_secs(2))
+                .unwrap_or_else(Instant::now), // trigger immediately on first loop
+            last_disks_poll: Instant::now()
+                .checked_sub(Duration::from_secs(5))
+                .unwrap_or_else(Instant::now),
+            procs_interval: Duration::from_secs(2),
+            disks_interval: Duration::from_secs(5),
+            metrics_interval: Duration::from_millis(500),
+            ws_url: String::new(),
+            is_tls: false,
+            has_token: false,
+        }
+    }
+}

socktop/src/history.rs

@@ -17,7 +17,10 @@ pub struct PerCoreHistory {
 
 impl PerCoreHistory {
     pub fn new(cap: usize) -> Self {
-        Self { deques: Vec::new(), cap }
+        Self {
+            deques: Vec::new(),
+            cap,
+        }
     }
 
     // Ensure we have one deque per core; resize on CPU topology changes
@@ -36,4 +39,4 @@ impl PerCoreHistory {
             push_capped(&mut self.deques[i], val, self.cap);
         }
     }
-}
+}

socktop/src/lib.rs

@@ -0,0 +1,4 @@
+//! Library surface for integration tests and reuse.
+
+pub mod types;
+pub mod ws;

socktop/src/main.rs

@@ -2,22 +2,419 @@
 
 mod app;
 mod history;
+mod profiles;
 mod types;
 mod ui;
 mod ws;
 
-use std::env;
 use app::App;
+use profiles::{load_profiles, save_profiles, ProfileEntry, ProfileRequest, ResolveProfile};
+use std::env;
+use std::io::{self, Write};
+
+pub(crate) struct ParsedArgs {
+    url: Option<String>,
+    tls_ca: Option<String>,
+    profile: Option<String>,
+    save: bool,
+    demo: bool,
+    dry_run: bool, // hidden test helper: skip connecting
+    metrics_interval_ms: Option<u64>,
+    processes_interval_ms: Option<u64>,
+    verify_hostname: bool,
+}
+
+pub(crate) fn parse_args<I: IntoIterator<Item = String>>(args: I) -> Result<ParsedArgs, String> {
+    let mut it = args.into_iter();
+    let prog = it.next().unwrap_or_else(|| "socktop".into());
+    let mut url: Option<String> = None;
+    let mut tls_ca: Option<String> = None;
+    let mut profile: Option<String> = None;
+    let mut save = false;
+    let mut demo = false;
+    let mut dry_run = false;
+    let mut metrics_interval_ms: Option<u64> = None;
+    let mut processes_interval_ms: Option<u64> = None;
+    let mut verify_hostname = false;
+    while let Some(arg) = it.next() {
+        match arg.as_str() {
+            "-h" | "--help" => {
+                return Err(format!("Usage: {prog} [--tls-ca CERT_PEM|-t CERT_PEM] [--verify-hostname] [--profile NAME|-P NAME] [--save] [--demo] [--metrics-interval-ms N] [--processes-interval-ms N] [ws://HOST:PORT/ws]\n"));
+            }
+            "--tls-ca" | "-t" => {
+                tls_ca = it.next();
+            }
+            "--verify-hostname" => {
+                // opt-in hostname (SAN) verification
+                // default behavior is to skip it for easier home network usage
+                // (still pins the provided certificate)
+                verify_hostname = true;
+            }
+            "--profile" | "-P" => {
+                profile = it.next();
+            }
+            "--save" => {
+                save = true;
+            }
+            "--demo" => {
+                demo = true;
+            }
+            "--dry-run" => {
+                // intentionally undocumented
+                dry_run = true;
+            }
+            "--metrics-interval-ms" => {
+                metrics_interval_ms = it.next().and_then(|v| v.parse().ok());
+            }
+            "--processes-interval-ms" => {
+                processes_interval_ms = it.next().and_then(|v| v.parse().ok());
+            }
+            _ if arg.starts_with("--tls-ca=") => {
+                if let Some((_, v)) = arg.split_once('=') {
+                    if !v.is_empty() {
+                        tls_ca = Some(v.to_string());
+                    }
+                }
+            }
+            _ if arg.starts_with("--profile=") => {
+                if let Some((_, v)) = arg.split_once('=') {
+                    if !v.is_empty() {
+                        profile = Some(v.to_string());
+                    }
+                }
+            }
+            _ if arg.starts_with("--metrics-interval-ms=") => {
+                if let Some((_, v)) = arg.split_once('=') {
+                    metrics_interval_ms = v.parse().ok();
+                }
+            }
+            _ if arg.starts_with("--processes-interval-ms=") => {
+                if let Some((_, v)) = arg.split_once('=') {
+                    processes_interval_ms = v.parse().ok();
+                }
+            }
+            _ => {
+                if url.is_none() {
+                    url = Some(arg);
+                } else {
+                    return Err(format!("Unexpected argument. Usage: {prog} [--tls-ca CERT_PEM|-t CERT_PEM] [--verify-hostname] [--profile NAME|-P NAME] [--save] [--demo] [ws://HOST:PORT/ws]"));
+                }
+            }
+        }
+    }
+    Ok(ParsedArgs {
+        url,
+        tls_ca,
+        profile,
+        save,
+        demo,
+        dry_run,
+        metrics_interval_ms,
+        processes_interval_ms,
+        verify_hostname,
+    })
+}
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let args: Vec<String> = env::args().collect();
-    if args.len() < 2 {
-        eprintln!("Usage: {} ws://HOST:PORT/ws", args[0]);
-        std::process::exit(1);
+    let parsed = match parse_args(env::args()) {
+        Ok(v) => v,
+        Err(msg) => {
+            eprintln!("{msg}");
+            return Ok(());
+        }
+    };
+    if parsed.demo || matches!(parsed.profile.as_deref(), Some("demo")) {
+        return run_demo_mode(parsed.tls_ca.as_deref()).await;
     }
-    let url = args[1].clone();
+    if parsed.verify_hostname {
+        // Set env var consumed by ws::connect logic
+        std::env::set_var("SOCKTOP_VERIFY_NAME", "1");
+    }
+    let profiles_file = load_profiles();
+    let req = ProfileRequest {
+        profile_name: parsed.profile.clone(),
+        url: parsed.url.clone(),
+        tls_ca: parsed.tls_ca.clone(),
+    };
+    let resolved = req.resolve(&profiles_file);
+    let mut profiles_mut = profiles_file.clone();
+    let (url, tls_ca, metrics_interval_ms, processes_interval_ms): (
+        String,
+        Option<String>,
+        Option<u64>,
+        Option<u64>,
+    ) = match resolved {
+        ResolveProfile::Direct(u, t) => {
+            if let Some(name) = parsed.profile.as_ref() {
+                let existing = profiles_mut.profiles.get(name);
+                match existing {
+                    None => {
+                        let (mi, pi) = gather_intervals(
+                            parsed.metrics_interval_ms,
+                            parsed.processes_interval_ms,
+                        )?;
+                        profiles_mut.profiles.insert(
+                            name.clone(),
+                            ProfileEntry {
+                                url: u.clone(),
+                                tls_ca: t.clone(),
+                                metrics_interval_ms: mi,
+                                processes_interval_ms: pi,
+                            },
+                        );
+                        let _ = save_profiles(&profiles_mut);
+                        (u, t, mi, pi)
+                    }
+                    Some(entry) => {
+                        let changed = entry.url != u || entry.tls_ca != t;
+                        if changed {
+                            let overwrite = if parsed.save {
+                                true
+                            } else {
+                                prompt_yes_no(&format!(
+                                    "Overwrite existing profile '{name}'? [y/N]: "
+                                ))
+                            };
+                            if overwrite {
+                                let (mi, pi) = gather_intervals(
+                                    parsed.metrics_interval_ms,
+                                    parsed.processes_interval_ms,
+                                )?;
+                                profiles_mut.profiles.insert(
+                                    name.clone(),
+                                    ProfileEntry {
+                                        url: u.clone(),
+                                        tls_ca: t.clone(),
+                                        metrics_interval_ms: mi,
+                                        processes_interval_ms: pi,
+                                    },
+                                );
+                                let _ = save_profiles(&profiles_mut);
+                                (u, t, mi, pi)
+                            } else {
+                                (u, t, entry.metrics_interval_ms, entry.processes_interval_ms)
+                            }
+                        } else {
+                            (u, t, entry.metrics_interval_ms, entry.processes_interval_ms)
+                        }
+                    }
+                }
+            } else {
+                (
+                    u,
+                    t,
+                    parsed.metrics_interval_ms,
+                    parsed.processes_interval_ms,
+                )
+            }
+        }
+        ResolveProfile::Loaded(u, t) => {
+            let entry = profiles_mut
+                .profiles
+                .get(parsed.profile.as_ref().unwrap())
+                .unwrap();
+            (u, t, entry.metrics_interval_ms, entry.processes_interval_ms)
+        }
+        ResolveProfile::PromptSelect(mut names) => {
+            if !names.iter().any(|n: &String| n == "demo") {
+                names.push("demo".into());
+            }
+            eprintln!("Select profile:");
+            for (i, n) in names.iter().enumerate() {
+                eprintln!("  {}. {}", i + 1, n);
+            }
+            eprint!("Enter number (or blank to abort): ");
+            let _ = io::stderr().flush();
+            let mut line = String::new();
+            if io::stdin().read_line(&mut line).is_ok() {
+                if let Ok(idx) = line.trim().parse::<usize>() {
+                    if idx >= 1 && idx <= names.len() {
+                        let name = &names[idx - 1];
+                        if name == "demo" {
+                            return run_demo_mode(parsed.tls_ca.as_deref()).await;
+                        }
+                        if let Some(entry) = profiles_mut.profiles.get(name) {
+                            (
+                                entry.url.clone(),
+                                entry.tls_ca.clone(),
+                                entry.metrics_interval_ms,
+                                entry.processes_interval_ms,
+                            )
+                        } else {
+                            return Ok(());
+                        }
+                    } else {
+                        return Ok(());
+                    }
+                } else {
+                    return Ok(());
+                }
+            } else {
+                return Ok(());
+            }
+        }
+        ResolveProfile::PromptCreate(name) => {
+            eprintln!("Profile '{name}' does not exist yet.");
+            let url = prompt_string("Enter URL (ws://HOST:PORT/ws or wss://...): ")?;
+            if url.trim().is_empty() {
+                return Ok(());
+            }
+            let ca = prompt_string("Enter TLS CA path (or leave blank): ")?;
+            let ca_opt = if ca.trim().is_empty() {
+                None
+            } else {
+                Some(ca.trim().to_string())
+            };
+            let (mi, pi) =
+                gather_intervals(parsed.metrics_interval_ms, parsed.processes_interval_ms)?;
+            profiles_mut.profiles.insert(
+                name.clone(),
+                ProfileEntry {
+                    url: url.trim().to_string(),
+                    tls_ca: ca_opt.clone(),
+                    metrics_interval_ms: mi,
+                    processes_interval_ms: pi,
+                },
+            );
+            let _ = save_profiles(&profiles_mut);
+            (url.trim().to_string(), ca_opt, mi, pi)
+        }
+        ResolveProfile::None => {
+            //eprintln!("No URL provided and no profiles to select.");
 
+            //first run, no args, no profiles: show welcome message and offer demo mode
+            if profiles_mut.profiles.is_empty() && parsed.url.is_none() {
+                eprintln!("Welcome to socktop!");
+                eprintln!("It looks like this is your first time running the application.");
+                eprintln!("You can connect to a socktop_agent instance to monitor system metrics and processes.");
+                eprintln!("If you don't have an agent running, you can try the demo mode.");
+                if prompt_yes_no("Would you like to start the demo mode now? [Y/n]: ") {
+                    return run_demo_mode(parsed.tls_ca.as_deref()).await;
+                } else {
+                    eprintln!("Aborting. You can run 'socktop --help' for usage information.");
+                    return Ok(());
+                }
+            }
+            return Err("No URL provided and no profiles to select.".into());
+        }
+    };
+
+    let is_tls = url.starts_with("wss://");
+    let has_token = url.contains("token=");
+    let mut app = App::new()
+        .with_intervals(metrics_interval_ms, processes_interval_ms)
+        .with_status(is_tls, has_token);
+    if parsed.dry_run {
+        return Ok(());
+    }
+    app.run(&url, tls_ca.as_deref()).await
+}
+
+fn prompt_yes_no(prompt: &str) -> bool {
+    eprint!("{prompt}");
+    let _ = io::stderr().flush();
+    let mut line = String::new();
+    if io::stdin().read_line(&mut line).is_ok() {
+        matches!(line.trim().to_ascii_lowercase().as_str(), "y" | "yes")
+    } else {
+        false
+    }
+}
+fn prompt_string(prompt: &str) -> io::Result<String> {
+    eprint!("{prompt}");
+    let _ = io::stderr().flush();
+    let mut line = String::new();
+    io::stdin().read_line(&mut line)?;
+    Ok(line)
+}
+
+fn gather_intervals(
+    arg_metrics: Option<u64>,
+    arg_procs: Option<u64>,
+) -> Result<(Option<u64>, Option<u64>), Box<dyn std::error::Error>> {
+    let default_metrics = 500u64;
+    let default_procs = 2000u64;
+    let metrics = match arg_metrics {
+        Some(v) => Some(v),
+        None => {
+            let inp = prompt_string(&format!(
+                "Metrics interval ms (default {default_metrics}, Enter for default): "
+            ))?;
+            let t = inp.trim();
+            if t.is_empty() {
+                Some(default_metrics)
+            } else {
+                Some(t.parse()?)
+            }
+        }
+    };
+    let procs = match arg_procs {
+        Some(v) => Some(v),
+        None => {
+            let inp = prompt_string(&format!(
+                "Processes interval ms (default {default_procs}, Enter for default): "
+            ))?;
+            let t = inp.trim();
+            if t.is_empty() {
+                Some(default_procs)
+            } else {
+                Some(t.parse()?)
+            }
+        }
+    };
+    Ok((metrics, procs))
+}
+
+// Demo mode implementation
+async fn run_demo_mode(_tls_ca: Option<&str>) -> Result<(), Box<dyn std::error::Error>> {
+    let port = 3231;
+    let url = format!("ws://127.0.0.1:{port}/ws");
+    let child = spawn_demo_agent(port)?;
     let mut app = App::new();
-    app.run(&url).await
-}
+    tokio::select! { res=app.run(&url,None)=>{ drop(child); res } _=tokio::signal::ctrl_c()=>{ drop(child); Ok(()) } }
+}
+struct DemoGuard {
+    port: u16,
+    child: std::sync::Arc<std::sync::Mutex<Option<std::process::Child>>>,
+}
+impl Drop for DemoGuard {
+    fn drop(&mut self) {
+        if let Some(mut ch) = self.child.lock().unwrap().take() {
+            let _ = ch.kill();
+        }
+        eprintln!("Stopped demo agent on port {}", self.port);
+    }
+}
+fn spawn_demo_agent(port: u16) -> Result<DemoGuard, Box<dyn std::error::Error>> {
+    let candidate = find_agent_executable();
+    let mut cmd = std::process::Command::new(candidate);
+    cmd.arg("--port").arg(port.to_string());
+    cmd.env("SOCKTOP_ENABLE_SSL", "0");
+
+    //JW: do not disable GPU and TEMP in demo mode
+    //cmd.env("SOCKTOP_AGENT_GPU", "0");
+    //cmd.env("SOCKTOP_AGENT_TEMP", "0");
+
+    let child = cmd.spawn()?;
+    std::thread::sleep(std::time::Duration::from_millis(300));
+    Ok(DemoGuard {
+        port,
+        child: std::sync::Arc::new(std::sync::Mutex::new(Some(child))),
+    })
+}
+fn find_agent_executable() -> std::path::PathBuf {
+    if let Ok(exe) = std::env::current_exe() {
+        if let Some(parent) = exe.parent() {
+            #[cfg(windows)]
+            let name = "socktop_agent.exe";
+            #[cfg(not(windows))]
+            let name = "socktop_agent";
+            let candidate = parent.join(name);
+            if candidate.exists() {
+                return candidate;
+            }
+        }
+    }
+    std::path::PathBuf::from("socktop_agent")
+}

socktop/src/profiles.rs

@@ -0,0 +1,102 @@
+//! Connection profiles: load/save simple JSON mapping of profile name -> { url, tls_ca }
+//! Stored under XDG config dir: $XDG_CONFIG_HOME/socktop/profiles.json (fallback ~/.config/socktop/profiles.json)
+
+use serde::{Deserialize, Serialize};
+use std::{collections::BTreeMap, fs, path::PathBuf};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct ProfileEntry {
+    pub url: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tls_ca: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub metrics_interval_ms: Option<u64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub processes_interval_ms: Option<u64>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct ProfilesFile {
+    #[serde(default)]
+    pub profiles: BTreeMap<String, ProfileEntry>,
+    #[serde(default)]
+    pub version: u32,
+}
+
+pub fn config_dir() -> PathBuf {
+    if let Some(xdg) = std::env::var_os("XDG_CONFIG_HOME") {
+        PathBuf::from(xdg).join("socktop")
+    } else {
+        dirs_next::config_dir()
+            .unwrap_or_else(|| PathBuf::from("."))
+            .join("socktop")
+    }
+}
+
+pub fn profiles_path() -> PathBuf {
+    config_dir().join("profiles.json")
+}
+
+pub fn load_profiles() -> ProfilesFile {
+    let path = profiles_path();
+    match fs::read_to_string(&path) {
+        Ok(s) => serde_json::from_str(&s).unwrap_or_default(),
+        Err(_) => ProfilesFile::default(),
+    }
+}
+
+pub fn save_profiles(p: &ProfilesFile) -> std::io::Result<()> {
+    let path = profiles_path();
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)?;
+    }
+    let data = serde_json::to_vec_pretty(p).expect("serialize profiles");
+    fs::write(path, data)
+}
+
+pub enum ResolveProfile {
+    /// Use the provided runtime inputs (not persisted). (url, tls_ca)
+    Direct(String, Option<String>),
+    /// Loaded from existing profile entry (url, tls_ca)
+    Loaded(String, Option<String>),
+    /// Should prompt user to select among profile names
+    PromptSelect(Vec<String>),
+    /// Should prompt user to create a new profile (name)
+    PromptCreate(String),
+    /// No profile could be resolved (e.g., missing arguments)
+    None,
+}
+
+pub struct ProfileRequest {
+    pub profile_name: Option<String>,
+    pub url: Option<String>,
+    pub tls_ca: Option<String>,
+}
+
+impl ProfileRequest {
+    pub fn resolve(self, pf: &ProfilesFile) -> ResolveProfile {
+        // Case: only profile name given -> try load
+        if self.url.is_none() && self.profile_name.is_some() {
+            let name = self.profile_name.unwrap();
+            if let Some(entry) = pf.profiles.get(&name) {
+                return ResolveProfile::Loaded(entry.url.clone(), entry.tls_ca.clone());
+            } else {
+                return ResolveProfile::PromptCreate(name);
+            }
+        }
+        // Both provided -> direct (maybe later saved by caller)
+        if let Some(u) = self.url {
+            return ResolveProfile::Direct(u, self.tls_ca);
+        }
+        // Nothing provided -> maybe prompt select if profiles exist
+        if self.url.is_none() && self.profile_name.is_none() {
+            if pf.profiles.is_empty() {
+                ResolveProfile::None
+            } else {
+                ResolveProfile::PromptSelect(pf.profiles.keys().cloned().collect())
+            }
+        } else {
+            ResolveProfile::None
+        }
+    }
+}

socktop/src/types.rs

@@ -2,21 +2,7 @@
 
 use serde::Deserialize;
 
-#[derive(Debug, Deserialize, Clone)]
-pub struct Disk {
-    pub name: String,
-    pub total: u64,
-    pub available: u64,
-}
-
-#[derive(Debug, Deserialize, Clone)]
-pub struct Network {
-    // cumulative totals; client diffs to compute rates
-    pub received: u64,
-    pub transmitted: u64,
-}
-
-#[derive(Debug, Deserialize, Clone)]
+#[derive(Debug, Clone, Deserialize)]
 pub struct ProcessInfo {
     pub pid: u32,
     pub name: String,
@@ -24,7 +10,48 @@ pub struct ProcessInfo {
     pub mem_bytes: u64,
 }
 
-#[derive(Debug, Deserialize, Clone)]
+#[derive(Debug, Clone, Deserialize)]
+pub struct DiskInfo {
+    pub name: String,
+    pub total: u64,
+    pub available: u64,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct NetworkInfo {
+    #[allow(dead_code)]
+    pub name: String,
+    pub received: u64,
+    pub transmitted: u64,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct GpuInfo {
+    pub name: Option<String>,
+    #[allow(dead_code)]
+    pub vendor: Option<String>,
+
+    // Accept both the new and legacy keys
+    #[serde(
+        default,
+        alias = "utilization_gpu_pct",
+        alias = "gpu_util_pct",
+        alias = "gpu_utilization"
+    )]
+    pub utilization: Option<f32>,
+
+    #[serde(default, alias = "mem_used_bytes", alias = "vram_used_bytes")]
+    pub mem_used: Option<u64>,
+
+    #[serde(default, alias = "mem_total_bytes", alias = "vram_total_bytes")]
+    pub mem_total: Option<u64>,
+
+    #[allow(dead_code)]
+    #[serde(default, alias = "temp_c", alias = "temperature_c")]
+    pub temperature: Option<f32>,
+}
+
+#[derive(Debug, Clone, Deserialize)]
 pub struct Metrics {
     pub cpu_total: f32,
     pub cpu_per_core: Vec<f32>,
@@ -32,10 +59,20 @@ pub struct Metrics {
     pub mem_used: u64,
     pub swap_total: u64,
     pub swap_used: u64,
-    pub process_count: usize,
     pub hostname: String,
     pub cpu_temp_c: Option<f32>,
-    pub disks: Vec<Disk>,
-    pub networks: Vec<Network>,
+    pub disks: Vec<DiskInfo>,
+    pub networks: Vec<NetworkInfo>,
     pub top_processes: Vec<ProcessInfo>,
-}
+    pub gpus: Option<Vec<GpuInfo>>,
+    // New: keep the last reported total process count
+    #[serde(default)]
+    pub process_count: Option<usize>,
+}
+
+#[allow(dead_code)]
+#[derive(Debug, Clone, Deserialize)]
+pub struct ProcessesPayload {
+    pub process_count: usize,
+    pub top_processes: Vec<ProcessInfo>,
+}

socktop/src/ui/cpu.rs

@@ -1,23 +1,250 @@
 //! CPU average sparkline + per-core mini bars.
 
+use crate::ui::theme::{SB_ARROW, SB_THUMB, SB_TRACK};
+use crossterm::event::{KeyCode, KeyEvent, MouseButton, MouseEvent, MouseEventKind};
+use ratatui::style::Modifier;
+use ratatui::style::{Color, Style};
 use ratatui::{
     layout::{Constraint, Direction, Layout, Rect},
-    style::{Color, Style},
     text::{Line, Span},
     widgets::{Block, Borders, Paragraph, Sparkline},
 };
-use ratatui::style::Modifier;
 
 use crate::history::PerCoreHistory;
 use crate::types::Metrics;
 
+/// State for dragging the scrollbar thumb
+#[derive(Clone, Copy, Debug, Default)]
+pub struct PerCoreScrollDrag {
+    pub active: bool,
+    pub start_y: u16,     // mouse row where drag started
+    pub start_top: usize, // thumb top (in track rows) at drag start
+}
+
+/// Returns the content area for per-core CPU bars, excluding borders and reserving space for scrollbar.
+pub fn per_core_content_area(area: Rect) -> Rect {
+    // Inner minus borders
+    let inner = Rect {
+        x: area.x + 1,
+        y: area.y + 1,
+        width: area.width.saturating_sub(2),
+        height: area.height.saturating_sub(2),
+    };
+    // Reserve 1 column on the right for a gutter and 1 for the scrollbar
+    Rect {
+        x: inner.x,
+        y: inner.y,
+        width: inner.width.saturating_sub(2),
+        height: inner.height,
+    }
+}
+
+/// Handles key events for per-core CPU bars.
+pub fn per_core_handle_key(scroll_offset: &mut usize, key: KeyEvent, page_size: usize) {
+    match key.code {
+        KeyCode::Up => *scroll_offset = scroll_offset.saturating_sub(1),
+        KeyCode::Down => *scroll_offset = scroll_offset.saturating_add(1),
+        KeyCode::PageUp => {
+            let step = page_size.max(1);
+            *scroll_offset = scroll_offset.saturating_sub(step);
+        }
+        KeyCode::PageDown => {
+            let step = page_size.max(1);
+            *scroll_offset = scroll_offset.saturating_add(step);
+        }
+        KeyCode::Home => *scroll_offset = 0,
+        KeyCode::End => *scroll_offset = usize::MAX, // draw() clamps to max
+        _ => {}
+    }
+}
+
+/// Handles mouse wheel over the content.
+pub fn per_core_handle_mouse(
+    scroll_offset: &mut usize,
+    mouse: MouseEvent,
+    content_area: Rect,
+    page_size: usize,
+) {
+    let inside = mouse.column >= content_area.x
+        && mouse.column < content_area.x + content_area.width
+        && mouse.row >= content_area.y
+        && mouse.row < content_area.y + content_area.height;
+
+    if !inside {
+        return;
+    }
+
+    match mouse.kind {
+        MouseEventKind::ScrollUp => *scroll_offset = scroll_offset.saturating_sub(1),
+        MouseEventKind::ScrollDown => *scroll_offset = scroll_offset.saturating_add(1),
+        // Optional paging via horizontal wheel
+        MouseEventKind::ScrollLeft => {
+            let step = page_size.max(1);
+            *scroll_offset = scroll_offset.saturating_sub(step);
+        }
+        MouseEventKind::ScrollRight => {
+            let step = page_size.max(1);
+            *scroll_offset = scroll_offset.saturating_add(step);
+        }
+        _ => {}
+    }
+}
+
+/// Handles mouse interaction with the scrollbar itself (click arrows/page/drag).
+pub fn per_core_handle_scrollbar_mouse(
+    scroll_offset: &mut usize,
+    drag: &mut Option<PerCoreScrollDrag>,
+    mouse: MouseEvent,
+    per_core_area: Rect,
+    total_rows: usize,
+) {
+    // Geometry
+    let inner = Rect {
+        x: per_core_area.x + 1,
+        y: per_core_area.y + 1,
+        width: per_core_area.width.saturating_sub(2),
+        height: per_core_area.height.saturating_sub(2),
+    };
+    if inner.height < 3 || inner.width < 1 {
+        return;
+    }
+    let content = Rect {
+        x: inner.x,
+        y: inner.y,
+        width: inner.width.saturating_sub(2),
+        height: inner.height,
+    };
+    let scroll_area = Rect {
+        x: inner.x + inner.width.saturating_sub(1),
+        y: inner.y,
+        width: 1,
+        height: inner.height,
+    };
+    let viewport_rows = content.height as usize;
+    let total = total_rows.max(1);
+    let view = viewport_rows.clamp(1, total);
+    let max_off = total.saturating_sub(view);
+    let mut offset = (*scroll_offset).min(max_off);
+
+    // Track and current thumb
+    let track = (scroll_area.height - 2) as usize;
+    if track == 0 {
+        return;
+    }
+    let thumb_len = (track * view).div_ceil(total).max(1).min(track);
+    let top_for_offset = |off: usize| -> usize {
+        if max_off == 0 {
+            0
+        } else {
+            ((track - thumb_len) * off + max_off / 2) / max_off
+        }
+    };
+    let thumb_top = top_for_offset(offset);
+
+    let inside_scrollbar = mouse.column == scroll_area.x
+        && mouse.row >= scroll_area.y
+        && mouse.row < scroll_area.y + scroll_area.height;
+
+    // Helper to page
+    let page_up = || offset.saturating_sub(view.max(1));
+    let page_down = || offset.saturating_add(view.max(1));
+
+    match mouse.kind {
+        MouseEventKind::Down(MouseButton::Left) if inside_scrollbar => {
+            // Where within the track?
+            let row = mouse.row;
+            if row == scroll_area.y {
+                // Top arrow
+                offset = offset.saturating_sub(1);
+            } else if row + 1 == scroll_area.y + scroll_area.height {
+                // Bottom arrow
+                offset = offset.saturating_add(1);
+            } else {
+                // Inside track
+                let rel = (row - (scroll_area.y + 1)) as usize;
+                let thumb_end = thumb_top + thumb_len;
+                if rel < thumb_top {
+                    // Page up
+                    offset = page_up();
+                } else if rel >= thumb_end {
+                    // Page down
+                    offset = page_down();
+                } else {
+                    // Start dragging
+                    *drag = Some(PerCoreScrollDrag {
+                        active: true,
+                        start_y: row,
+                        start_top: thumb_top,
+                    });
+                }
+            }
+        }
+        MouseEventKind::Drag(MouseButton::Left) => {
+            if let Some(mut d) = drag.take() {
+                if d.active {
+                    let dy = (mouse.row as i32) - (d.start_y as i32);
+                    let new_top = (d.start_top as i32 + dy)
+                        .clamp(0, (track.saturating_sub(thumb_len)) as i32)
+                        as usize;
+                    // Inverse mapping top -> offset
+                    if track > thumb_len {
+                        let denom = track - thumb_len;
+                        offset = if max_off == 0 {
+                            0
+                        } else {
+                            (new_top * max_off + denom / 2) / denom
+                        };
+                    } else {
+                        offset = 0;
+                    }
+                    // Keep dragging
+                    d.start_top = new_top;
+                    d.start_y = mouse.row;
+                    *drag = Some(d);
+                }
+            }
+        }
+        MouseEventKind::Up(MouseButton::Left) => {
+            // End drag
+            *drag = None;
+        }
+        // Also allow wheel scrolling when cursor is over the scrollbar
+        MouseEventKind::ScrollUp if inside_scrollbar => {
+            offset = offset.saturating_sub(1);
+        }
+        MouseEventKind::ScrollDown if inside_scrollbar => {
+            offset = offset.saturating_add(1);
+        }
+        _ => {}
+    }
+
+    // Clamp and write back
+    if offset > max_off {
+        offset = max_off;
+    }
+    *scroll_offset = offset;
+}
+
+/// Clamp scroll offset to the valid range given content and viewport.
+pub fn per_core_clamp(scroll_offset: &mut usize, total_rows: usize, viewport_rows: usize) {
+    let max_offset = total_rows.saturating_sub(viewport_rows);
+    if *scroll_offset > max_offset {
+        *scroll_offset = max_offset;
+    }
+}
+
+/// Draws the CPU average sparkline graph.
 pub fn draw_cpu_avg_graph(
     f: &mut ratatui::Frame<'_>,
     area: Rect,
     hist: &std::collections::VecDeque<u64>,
     m: Option<&Metrics>,
 ) {
-    let title = if let Some(mm) = m { format!("CPU avg (now: {:>5.1}%)", mm.cpu_total) } else { "CPU avg".into() };
+    let title = if let Some(mm) = m {
+        format!("CPU avg (now: {:>5.1}%)", mm.cpu_total)
+    } else {
+        "CPU avg".into()
+    };
     let max_points = area.width.saturating_sub(2) as usize;
     let start = hist.len().saturating_sub(max_points);
     let data: Vec<u64> = hist.iter().skip(start).cloned().collect();
@@ -29,38 +256,74 @@ pub fn draw_cpu_avg_graph(
     f.render_widget(spark, area);
 }
 
+/// Draws the per-core CPU bars with sparklines and trends.
 pub fn draw_per_core_bars(
     f: &mut ratatui::Frame<'_>,
     area: Rect,
     m: Option<&Metrics>,
     per_core_hist: &PerCoreHistory,
+    scroll_offset: usize,
 ) {
-    f.render_widget(Block::default().borders(Borders::ALL).title("Per-core"), area);
-    let Some(mm) = m else { return; };
+    f.render_widget(
+        Block::default().borders(Borders::ALL).title("Per-core"),
+        area,
+    );
+    let Some(mm) = m else {
+        return;
+    };
 
-    let inner = Rect { x: area.x + 1, y: area.y + 1, width: area.width.saturating_sub(2), height: area.height.saturating_sub(2) };
-    if inner.height == 0 { return; }
+    // Compute inner rect and content area
+    let inner = Rect {
+        x: area.x + 1,
+        y: area.y + 1,
+        width: area.width.saturating_sub(2),
+        height: area.height.saturating_sub(2),
+    };
+    if inner.height == 0 || inner.width <= 2 {
+        return;
+    }
+    let content = Rect {
+        x: inner.x,
+        y: inner.y,
+        width: inner.width.saturating_sub(2),
+        height: inner.height,
+    };
+
+    let total_rows = mm.cpu_per_core.len();
+    let viewport_rows = content.height as usize;
+    let max_offset = total_rows.saturating_sub(viewport_rows);
+    let offset = scroll_offset.min(max_offset);
+    let show_n = total_rows.saturating_sub(offset).min(viewport_rows);
 
-    let rows = inner.height as usize;
-    let show_n = rows.min(mm.cpu_per_core.len());
     let constraints: Vec<Constraint> = (0..show_n).map(|_| Constraint::Length(1)).collect();
-    let vchunks = Layout::default().direction(Direction::Vertical).constraints(constraints).split(inner);
+    let vchunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints(constraints)
+        .split(content);
 
     for i in 0..show_n {
+        let idx = offset + i;
         let rect = vchunks[i];
         let hchunks = Layout::default()
             .direction(Direction::Horizontal)
             .constraints([Constraint::Min(6), Constraint::Length(12)])
             .split(rect);
 
-        let curr = mm.cpu_per_core[i].clamp(0.0, 100.0);
-        let older = per_core_hist.deques.get(i)
+        let curr = mm.cpu_per_core[idx].clamp(0.0, 100.0);
+        let older = per_core_hist
+            .deques
+            .get(idx)
             .and_then(|d| d.iter().rev().nth(20).copied())
             .map(|v| v as f32)
             .unwrap_or(curr);
-        let trend = if curr > older + 0.2 { "↑" }
-                    else if curr + 0.2 < older { "↓" }
-                    else { "╌" };
+
+        let trend = if curr > older + 0.2 {
+            "↑"
+        } else if curr + 0.2 < older {
+            "↓"
+        } else {
+            "╌"
+        };
 
         let fg = match curr {
             x if x < 25.0 => Color::Green,
@@ -70,7 +333,7 @@ pub fn draw_per_core_bars(
 
         let hist: Vec<u64> = per_core_hist
             .deques
-            .get(i)
+            .get(idx)
             .map(|d| {
                 let max_points = hchunks[0].width as usize;
                 let start = d.len().saturating_sub(max_points);
@@ -82,10 +345,49 @@ pub fn draw_per_core_bars(
             .data(&hist)
             .max(100)
             .style(Style::default().fg(fg));
+
         f.render_widget(spark, hchunks[0]);
 
-        let label = format!("cpu{:<2}{}{:>5.1}%", i, trend, curr);
-        let line = Line::from(Span::styled(label, Style::default().fg(fg).add_modifier(Modifier::BOLD)));
+        let label = format!("cpu{idx:<2}{trend}{curr:>5.1}%");
+        let line = Line::from(Span::styled(
+            label,
+            Style::default().fg(fg).add_modifier(Modifier::BOLD),
+        ));
         f.render_widget(Paragraph::new(line).right_aligned(), hchunks[1]);
     }
-}
+
+    // Custom 1-col scrollbar with arrows, track, and exact mapping
+    let scroll_area = Rect {
+        x: inner.x + inner.width.saturating_sub(1),
+        y: inner.y,
+        width: 1,
+        height: inner.height,
+    };
+    if scroll_area.height >= 3 {
+        let track = (scroll_area.height - 2) as usize;
+        let total = total_rows.max(1);
+        let view = viewport_rows.clamp(1, total);
+        let max_off = total.saturating_sub(view);
+
+        let thumb_len = (track * view).div_ceil(total).max(1).min(track);
+        let thumb_top = if max_off == 0 {
+            0
+        } else {
+            ((track - thumb_len) * offset + max_off / 2) / max_off
+        };
+
+        // Build lines: top arrow, track (with thumb), bottom arrow
+        let mut lines: Vec<Line> = Vec::with_capacity(scroll_area.height as usize);
+        lines.push(Line::from(Span::styled("▲", Style::default().fg(SB_ARROW))));
+        for i in 0..track {
+            if i >= thumb_top && i < thumb_top + thumb_len {
+                lines.push(Line::from(Span::styled("█", Style::default().fg(SB_THUMB))));
+            } else {
+                lines.push(Line::from(Span::styled("│", Style::default().fg(SB_TRACK))));
+            }
+        }
+        lines.push(Line::from(Span::styled("▼", Style::default().fg(SB_ARROW))));
+
+        f.render_widget(Paragraph::new(lines), scroll_area);
+    }
+}

socktop/src/ui/disks.rs

@@ -1,16 +1,18 @@
 //! Disk cards with per-device gauge and title line.
 
+use crate::types::Metrics;
+use crate::ui::util::{disk_icon, human, truncate_middle};
 use ratatui::{
     layout::{Constraint, Direction, Layout, Rect},
     style::Style,
     widgets::{Block, Borders, Gauge},
 };
-use crate::types::Metrics;
-use crate::ui::util::{human, truncate_middle, disk_icon};
 
 pub fn draw_disks(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
     f.render_widget(Block::default().borders(Borders::ALL).title("Disks"), area);
-    let Some(mm) = m else { return; };
+    let Some(mm) = m else {
+        return;
+    };
 
     let inner = Rect {
         x: area.x + 1,
@@ -18,12 +20,16 @@ pub fn draw_disks(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
         width: area.width.saturating_sub(2),
         height: area.height.saturating_sub(2),
     };
-    if inner.height < 3 { return; }
+    if inner.height < 3 {
+        return;
+    }
 
     let per_disk_h = 3u16;
     let max_cards = (inner.height / per_disk_h).min(mm.disks.len() as u16) as usize;
 
-    let constraints: Vec<Constraint> = (0..max_cards).map(|_| Constraint::Length(per_disk_h)).collect();
+    let constraints: Vec<Constraint> = (0..max_cards)
+        .map(|_| Constraint::Length(per_disk_h))
+        .collect();
     let rows = Layout::default()
         .direction(Direction::Vertical)
         .constraints(constraints)
@@ -32,10 +38,20 @@ pub fn draw_disks(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
     for (i, slot) in rows.iter().enumerate() {
         let d = &mm.disks[i];
         let used = d.total.saturating_sub(d.available);
-        let ratio = if d.total > 0 { used as f64 / d.total as f64 } else { 0.0 };
+        let ratio = if d.total > 0 {
+            used as f64 / d.total as f64
+        } else {
+            0.0
+        };
         let pct = (ratio * 100.0).round() as u16;
 
-        let color = if pct < 70 { ratatui::style::Color::Green } else if pct < 90 { ratatui::style::Color::Yellow } else { ratatui::style::Color::Red };
+        let color = if pct < 70 {
+            ratatui::style::Color::Green
+        } else if pct < 90 {
+            ratatui::style::Color::Yellow
+        } else {
+            ratatui::style::Color::Red
+        };
 
         let title = format!(
             "{} {}   {} / {}  ({}%)",
@@ -55,7 +71,9 @@ pub fn draw_disks(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
             width: slot.width.saturating_sub(2),
             height: slot.height.saturating_sub(2),
         };
-        if inner_card.height == 0 { continue; }
+        if inner_card.height == 0 {
+            continue;
+        }
 
         let gauge_rect = Rect {
             x: inner_card.x,
@@ -70,4 +88,4 @@ pub fn draw_disks(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
 
         f.render_widget(g, gauge_rect);
     }
-}
+}

socktop/src/ui/gpu.rs

@@ -0,0 +1,123 @@
+use ratatui::{
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Style},
+    text::Span,
+    widgets::{Block, Borders, Gauge, Paragraph},
+};
+
+use crate::types::Metrics;
+
+fn fmt_bytes(b: u64) -> String {
+    const KB: f64 = 1024.0;
+    const MB: f64 = KB * 1024.0;
+    const GB: f64 = MB * 1024.0;
+    let fb = b as f64;
+
+    if fb >= GB {
+        format!("{:.1}G", fb / GB)
+    } else if fb >= MB {
+        format!("{:.1}M", fb / MB)
+    } else if fb >= KB {
+        format!("{:.1}K", fb / KB)
+    } else {
+        format!("{b}B")
+    }
+}
+
+pub fn draw_gpu(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
+    let mut area = area;
+    let block = Block::default().borders(Borders::ALL).title("GPU");
+    f.render_widget(block, area);
+
+    // Guard: need some space inside the block
+    if area.height <= 2 || area.width <= 2 {
+        return;
+    }
+
+    // Inner padding consistent with the rest of the app
+    area.y += 1;
+    area.height = area.height.saturating_sub(2);
+    area.x += 1;
+    area.width = area.width.saturating_sub(2);
+
+    let Some(metrics) = m else {
+        return;
+    };
+
+    let Some(gpus) = metrics.gpus.as_ref() else {
+        f.render_widget(Paragraph::new("No GPUs"), area);
+        return;
+    };
+    if gpus.is_empty() {
+        f.render_widget(Paragraph::new("No GPUs"), area);
+        return;
+    }
+
+    // Show 3 rows per GPU: name, util bar, vram bar.
+    if area.height < 3 {
+        return;
+    }
+    let per_gpu_rows: u16 = 3;
+    let max_gpus = (area.height / per_gpu_rows) as usize;
+    let count = gpus.len().min(max_gpus);
+
+    let constraints = vec![Constraint::Length(1); count * per_gpu_rows as usize];
+    let rows = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints(constraints)
+        .split(area);
+
+    // Per bar horizontal layout: [gauge] [value]
+    let split_bar = |r: Rect| {
+        Layout::default()
+            .direction(Direction::Horizontal)
+            .constraints([
+                Constraint::Min(8),     // gauge column
+                Constraint::Length(24), // value column
+            ])
+            .split(r)
+    };
+
+    for i in 0..count {
+        let g = &gpus[i];
+
+        // Row 1: GPU name
+        let name_text = g.name.as_deref().unwrap_or("GPU");
+        let name_p = Paragraph::new(Span::raw(name_text)).style(Style::default().fg(Color::Gray));
+        f.render_widget(name_p, rows[i * 3]);
+
+        // Row 2: Utilization bar + right label
+        let util_cols = split_bar(rows[i * 3 + 1]);
+        let util = g.utilization.unwrap_or(0.0).clamp(0.0, 100.0) as u16;
+        let util_gauge = Gauge::default()
+            .gauge_style(Style::default().fg(Color::Green))
+            .label(Span::raw(""))
+            .ratio(util as f64 / 100.0);
+        f.render_widget(util_gauge, util_cols[0]);
+        f.render_widget(
+            Paragraph::new(Span::raw(format!("util: {util}%")))
+                .style(Style::default().fg(Color::Gray)),
+            util_cols[1],
+        );
+
+        // Row 3: VRAM bar + right label
+        let mem_cols = split_bar(rows[i * 3 + 2]);
+        let used = g.mem_used.unwrap_or(0);
+        let total = g.mem_total.unwrap_or(1);
+        let mem_ratio = used as f64 / total as f64;
+        let mem_pct = (mem_ratio * 100.0).round() as u16;
+
+        let mem_gauge = Gauge::default()
+            .gauge_style(Style::default().fg(Color::LightMagenta))
+            .label(Span::raw(""))
+            .ratio(mem_ratio);
+        f.render_widget(mem_gauge, mem_cols[0]);
+        let used_s = fmt_bytes(used);
+        let total_s = fmt_bytes(total);
+        f.render_widget(
+            Paragraph::new(Span::raw(format!("vram: {used_s}/{total_s} ({mem_pct}%)")))
+                .style(Style::default().fg(Color::Gray)),
+            mem_cols[1],
+        );
+    }
+}

socktop/src/ui/header.rs

@@ -1,20 +1,52 @@
 //! Top header with hostname and CPU temperature indicator.
 
+use crate::types::Metrics;
 use ratatui::{
     layout::Rect,
     widgets::{Block, Borders},
 };
-use crate::types::Metrics;
+use std::time::Duration;
 
-pub fn draw_header(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
-    let title = if let Some(mm) = m {
-        let temp = mm.cpu_temp_c.map(|t| {
-            let icon = if t < 50.0 { "😎" } else if t < 85.0 { "⚠️" } else { "🔥" };
-            format!("CPU Temp: {:.1}°C {}", t, icon)
-        }).unwrap_or_else(|| "CPU Temp: N/A".into());
-        format!("socktop — host: {} | {}  (press 'q' to quit)", mm.hostname, temp)
+pub fn draw_header(
+    f: &mut ratatui::Frame<'_>,
+    area: Rect,
+    m: Option<&Metrics>,
+    is_tls: bool,
+    has_token: bool,
+    metrics_interval: Duration,
+    procs_interval: Duration,
+) {
+    let base = if let Some(mm) = m {
+        let temp = mm
+            .cpu_temp_c
+            .map(|t| {
+                let icon = if t < 50.0 {
+                    "😎"
+                } else if t < 85.0 {
+                    "⚠️"
+                } else {
+                    "🔥"
+                };
+                format!("CPU Temp: {t:.1}°C {icon}")
+            })
+            .unwrap_or_else(|| "CPU Temp: N/A".into());
+        format!("socktop — host: {} | {}", mm.hostname, temp)
     } else {
-        "socktop — connecting... (press 'q' to quit)".into()
+        "socktop — connecting...".into()
     };
+    // TLS indicator: lock vs lock with cross (using ✗). Keep explicit label for clarity.
+    let tls_txt = if is_tls { "🔒 TLS" } else { "🔒✗ TLS" };
+    // Token indicator
+    let tok_txt = if has_token { "🔑 token" } else { "" };
+    let mi = metrics_interval.as_millis();
+    let pi = procs_interval.as_millis();
+    let intervals = format!("⏱  {mi}ms metrics | {pi}ms procs");
+    let mut parts = vec![base, tls_txt.into()];
+    if !tok_txt.is_empty() {
+        parts.push(tok_txt.into());
+    }
+    parts.push(intervals);
+    parts.push("(q to quit)".into());
+    let title = parts.join(" | ");
     f.render_widget(Block::default().title(title).borders(Borders::BOTTOM), area);
-}
+}

socktop/src/ui/mem.rs

@@ -1,18 +1,24 @@
 //! Memory gauge.
 
+use crate::types::Metrics;
+use crate::ui::util::human;
 use ratatui::{
     layout::Rect,
     style::{Color, Style},
     widgets::{Block, Borders, Gauge},
 };
-use crate::types::Metrics;
-use crate::ui::util::human;
 
 pub fn draw_mem(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
     let (used, total, pct) = if let Some(mm) = m {
-        let pct = if mm.mem_total > 0 { (mm.mem_used as f64 / mm.mem_total as f64 * 100.0) as u16 } else { 0 };
+        let pct = if mm.mem_total > 0 {
+            (mm.mem_used as f64 / mm.mem_total as f64 * 100.0) as u16
+        } else {
+            0
+        };
         (mm.mem_used, mm.mem_total, pct)
-    } else { (0, 0, 0) };
+    } else {
+        (0, 0, 0)
+    };
 
     let g = Gauge::default()
         .block(Block::default().borders(Borders::ALL).title("Memory"))
@@ -20,4 +26,4 @@ pub fn draw_mem(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
         .percent(pct)
         .label(format!("{} / {}", human(used), human(total)));
     f.render_widget(g, area);
-}
+}

socktop/src/ui/mod.rs

@@ -1,10 +1,12 @@
 //! UI module root: exposes drawing functions for individual panels.
 
-pub mod header;
 pub mod cpu;
-pub mod mem;
-pub mod swap;
 pub mod disks;
+pub mod gpu;
+pub mod header;
+pub mod mem;
 pub mod net;
 pub mod processes;
-pub mod util;
+pub mod swap;
+pub mod theme;
+pub mod util;

socktop/src/ui/net.rs

@@ -1,11 +1,11 @@
 //! Network sparklines (download/upload).
 
-use std::collections::VecDeque;
 use ratatui::{
     layout::Rect,
     style::{Color, Style},
     widgets::{Block, Borders, Sparkline},
 };
+use std::collections::VecDeque;
 
 pub fn draw_net_spark(
     f: &mut ratatui::Frame<'_>,
@@ -19,8 +19,12 @@ pub fn draw_net_spark(
     let data: Vec<u64> = hist.iter().skip(start).cloned().collect();
 
     let spark = Sparkline::default()
-        .block(Block::default().borders(Borders::ALL).title(title.to_string()))
+        .block(
+            Block::default()
+                .borders(Borders::ALL)
+                .title(title.to_string()),
+        )
         .data(&data)
         .style(Style::default().fg(color));
     f.render_widget(spark, area);
-}
+}

socktop/src/ui/processes.rs

@@ -1,29 +1,105 @@
-//! Top processes table with per-cell coloring and zebra striping.
+//! Top processes table with per-cell coloring, zebra striping, sorting, and a scrollbar.
 
-use ratatui::{
-    layout::{Constraint, Rect},
-    style::{Color, Style},
-    widgets::{Block, Borders, Cell, Row, Table},
-};
+use crossterm::event::{MouseButton, MouseEvent, MouseEventKind};
 use ratatui::style::Modifier;
+use ratatui::{
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph, Table},
+};
+use std::cmp::Ordering;
 
 use crate::types::Metrics;
+use crate::ui::cpu::{per_core_clamp, per_core_handle_scrollbar_mouse};
+use crate::ui::theme::{SB_ARROW, SB_THUMB, SB_TRACK};
 use crate::ui::util::human;
 
-pub fn draw_top_processes(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
-    let Some(mm) = m else {
-        f.render_widget(Block::default().borders(Borders::ALL).title("Top Processes"), area);
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub enum ProcSortBy {
+    #[default]
+    CpuDesc,
+    MemDesc,
+}
+
+// Keep the original header widths here so drawing and hit-testing match.
+const COLS: [Constraint; 5] = [
+    Constraint::Length(8),      // PID
+    Constraint::Percentage(40), // Name
+    Constraint::Length(8),      // CPU %
+    Constraint::Length(12),     // Mem
+    Constraint::Length(8),      // Mem %
+];
+
+pub fn draw_top_processes(
+    f: &mut ratatui::Frame<'_>,
+    area: Rect,
+    m: Option<&Metrics>,
+    scroll_offset: usize,
+    sort_by: ProcSortBy,
+) {
+    // Draw outer block and title
+    let Some(mm) = m else { return };
+    let total = mm.process_count.unwrap_or(mm.top_processes.len());
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .title(format!("Top Processes ({total} total)"));
+    f.render_widget(block, area);
+
+    // Inner area and content area (reserve 2 columns for scrollbar)
+    let inner = Rect {
+        x: area.x + 1,
+        y: area.y + 1,
+        width: area.width.saturating_sub(2),
+        height: area.height.saturating_sub(2),
+    };
+    if inner.height < 1 || inner.width < 3 {
         return;
+    }
+    let content = Rect {
+        x: inner.x,
+        y: inner.y,
+        width: inner.width.saturating_sub(2),
+        height: inner.height,
     };
 
-    let total_mem_bytes = mm.mem_total.max(1);
-    let title = format!("Top Processes ({} total)", mm.process_count);
-    let peak_cpu = mm.top_processes.iter().map(|p| p.cpu_usage).fold(0.0_f32, f32::max);
+    // Sort rows (by CPU% or Mem bytes), descending.
+    let mut idxs: Vec<usize> = (0..mm.top_processes.len()).collect();
+    match sort_by {
+        ProcSortBy::CpuDesc => idxs.sort_by(|&a, &b| {
+            let aa = mm.top_processes[a].cpu_usage;
+            let bb = mm.top_processes[b].cpu_usage;
+            bb.partial_cmp(&aa).unwrap_or(Ordering::Equal)
+        }),
+        ProcSortBy::MemDesc => idxs.sort_by(|&a, &b| {
+            let aa = mm.top_processes[a].mem_bytes;
+            let bb = mm.top_processes[b].mem_bytes;
+            bb.cmp(&aa)
+        }),
+    }
 
-    let rows: Vec<Row> = mm.top_processes.iter().enumerate().map(|(i, p)| {
+    // Scrolling
+    let total_rows = idxs.len();
+    let header_rows = 1usize;
+    let viewport_rows = content.height.saturating_sub(header_rows as u16) as usize;
+    let max_off = total_rows.saturating_sub(viewport_rows);
+    let offset = scroll_offset.min(max_off);
+    let show_n = total_rows.saturating_sub(offset).min(viewport_rows);
+
+    // Build visible rows
+    let total_mem_bytes = mm.mem_total.max(1);
+    let peak_cpu = mm
+        .top_processes
+        .iter()
+        .map(|p| p.cpu_usage)
+        .fold(0.0_f32, f32::max);
+
+    let rows_iter = idxs.iter().skip(offset).take(show_n).map(|&ix| {
+        let p = &mm.top_processes[ix];
         let mem_pct = (p.mem_bytes as f64 / total_mem_bytes as f64) * 100.0;
 
-        let cpu_fg = match p.cpu_usage {
+        let cpu_val = p.cpu_usage;
+        let cpu_fg = match cpu_val {
             x if x < 25.0 => Color::Green,
             x if x < 60.0 => Color::Yellow,
             _ => Color::Red,
@@ -34,38 +110,157 @@ pub fn draw_top_processes(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Met
             _ => Color::Red,
         };
 
-        let zebra = if i % 2 == 0 { Style::default().fg(Color::Gray) } else { Style::default() };
-
-        let emphasis = if (p.cpu_usage - peak_cpu).abs() < f32::EPSILON {
+        let emphasis = if (cpu_val - peak_cpu).abs() < f32::EPSILON {
             Style::default().add_modifier(Modifier::BOLD)
-        } else { Style::default() };
+        } else {
+            Style::default()
+        };
 
-        Row::new(vec![
-            Cell::from(p.pid.to_string()).style(Style::default().fg(Color::DarkGray)),
-            Cell::from(p.name.clone()),
-            Cell::from(format!("{:.1}%", p.cpu_usage)).style(Style::default().fg(cpu_fg)),
-            Cell::from(human(p.mem_bytes)),
-            Cell::from(format!("{:.2}%", mem_pct)).style(Style::default().fg(mem_fg)),
+        let cpu_str = fmt_cpu_pct(cpu_val);
+
+        ratatui::widgets::Row::new(vec![
+            ratatui::widgets::Cell::from(p.pid.to_string())
+                .style(Style::default().fg(Color::DarkGray)),
+            ratatui::widgets::Cell::from(p.name.clone()),
+            ratatui::widgets::Cell::from(cpu_str).style(Style::default().fg(cpu_fg)),
+            ratatui::widgets::Cell::from(human(p.mem_bytes)),
+            ratatui::widgets::Cell::from(format!("{mem_pct:.2}%"))
+                .style(Style::default().fg(mem_fg)),
         ])
-        .style(zebra.patch(emphasis))
-    }).collect();
+        .style(emphasis)
+    });
 
-    let header = Row::new(vec!["PID", "Name", "CPU %", "Mem", "Mem %"])
-        .style(Style::default().fg(Color::Cyan).add_modifier(Modifier::BOLD));
+    // Header with sort indicator
+    let cpu_hdr = match sort_by {
+        ProcSortBy::CpuDesc => "CPU % •",
+        _ => "CPU %",
+    };
+    let mem_hdr = match sort_by {
+        ProcSortBy::MemDesc => "Mem •",
+        _ => "Mem",
+    };
+    let header = ratatui::widgets::Row::new(vec!["PID", "Name", cpu_hdr, mem_hdr, "Mem %"]).style(
+        Style::default()
+            .fg(Color::Cyan)
+            .add_modifier(Modifier::BOLD),
+    );
 
-    let table = Table::new(
-            rows,
-            vec![
-                Constraint::Length(8),
-                Constraint::Percentage(40),
-                Constraint::Length(8),
-                Constraint::Length(12),
-                Constraint::Length(8),
-            ],
-        )
+    // Render table inside content area (no borders here; outer block already drawn)
+    let table = Table::new(rows_iter, COLS.to_vec())
         .header(header)
-        .column_spacing(1)
-        .block(Block::default().borders(Borders::ALL).title(title));
+        .column_spacing(1);
+    f.render_widget(table, content);
 
-    f.render_widget(table, area);
-}
+    // Draw scrollbar like CPU pane
+    let scroll_area = Rect {
+        x: inner.x + inner.width.saturating_sub(1),
+        y: inner.y,
+        width: 1,
+        height: inner.height,
+    };
+    if scroll_area.height >= 3 {
+        let track = (scroll_area.height - 2) as usize;
+        let total = total_rows.max(1);
+        let view = viewport_rows.clamp(1, total);
+        let max_off = total.saturating_sub(view);
+
+        let thumb_len = (track * view).div_ceil(total).max(1).min(track);
+        let thumb_top = if max_off == 0 {
+            0
+        } else {
+            ((track - thumb_len) * offset + max_off / 2) / max_off
+        };
+
+        // Build lines: top arrow, track (with thumb), bottom arrow
+        let mut lines: Vec<Line> = Vec::with_capacity(scroll_area.height as usize);
+        lines.push(Line::from(Span::styled("▲", Style::default().fg(SB_ARROW))));
+        for i in 0..track {
+            if i >= thumb_top && i < thumb_top + thumb_len {
+                lines.push(Line::from(Span::styled("█", Style::default().fg(SB_THUMB))));
+            } else {
+                lines.push(Line::from(Span::styled("│", Style::default().fg(SB_TRACK))));
+            }
+        }
+        lines.push(Line::from(Span::styled("▼", Style::default().fg(SB_ARROW))));
+        f.render_widget(Paragraph::new(lines), scroll_area);
+    }
+}
+
+fn fmt_cpu_pct(v: f32) -> String {
+    format!("{:>5.1}", v.clamp(0.0, 100.0))
+}
+
+/// Handle keyboard scrolling (Up/Down/PageUp/PageDown/Home/End)
+pub fn processes_handle_key(
+    scroll_offset: &mut usize,
+    key: crossterm::event::KeyEvent,
+    page_size: usize,
+) {
+    crate::ui::cpu::per_core_handle_key(scroll_offset, key, page_size);
+}
+
+/// Handle mouse for content scrolling and scrollbar dragging.
+/// Returns Some(new_sort) if the header "CPU %" or "Mem" was clicked.
+pub fn processes_handle_mouse(
+    scroll_offset: &mut usize,
+    drag: &mut Option<crate::ui::cpu::PerCoreScrollDrag>,
+    mouse: MouseEvent,
+    area: Rect,
+    total_rows: usize,
+) -> Option<ProcSortBy> {
+    // Inner and content areas (match draw_top_processes)
+    let inner = Rect {
+        x: area.x + 1,
+        y: area.y + 1,
+        width: area.width.saturating_sub(2),
+        height: area.height.saturating_sub(2),
+    };
+    if inner.height == 0 || inner.width <= 2 {
+        return None;
+    }
+    let content = Rect {
+        x: inner.x,
+        y: inner.y,
+        width: inner.width.saturating_sub(2),
+        height: inner.height,
+    };
+
+    // Scrollbar interactions (click arrows/page/drag)
+    per_core_handle_scrollbar_mouse(scroll_offset, drag, mouse, area, total_rows);
+
+    // Wheel scrolling when inside the content
+    crate::ui::cpu::per_core_handle_mouse(scroll_offset, mouse, content, content.height as usize);
+
+    // Header click to change sort
+    let header_area = Rect {
+        x: content.x,
+        y: content.y,
+        width: content.width,
+        height: 1,
+    };
+    let inside_header = mouse.row == header_area.y
+        && mouse.column >= header_area.x
+        && mouse.column < header_area.x + header_area.width;
+
+    if inside_header && matches!(mouse.kind, MouseEventKind::Down(MouseButton::Left)) {
+        // Split header into the same columns
+        let cols = Layout::default()
+            .direction(Direction::Horizontal)
+            .constraints(COLS.to_vec())
+            .split(header_area);
+        if mouse.column >= cols[2].x && mouse.column < cols[2].x + cols[2].width {
+            return Some(ProcSortBy::CpuDesc);
+        }
+        if mouse.column >= cols[3].x && mouse.column < cols[3].x + cols[3].width {
+            return Some(ProcSortBy::MemDesc);
+        }
+    }
+
+    // Clamp to valid range
+    per_core_clamp(
+        scroll_offset,
+        total_rows,
+        (content.height.saturating_sub(1)) as usize,
+    );
+    None
+}

socktop/src/ui/swap.rs

@@ -1,18 +1,24 @@
 //! Swap gauge.
 
+use crate::types::Metrics;
+use crate::ui::util::human;
 use ratatui::{
     layout::Rect,
     style::{Color, Style},
     widgets::{Block, Borders, Gauge},
 };
-use crate::types::Metrics;
-use crate::ui::util::human;
 
 pub fn draw_swap(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
     let (used, total, pct) = if let Some(mm) = m {
-        let pct = if mm.swap_total > 0 { (mm.swap_used as f64 / mm.swap_total as f64 * 100.0) as u16 } else { 0 };
+        let pct = if mm.swap_total > 0 {
+            (mm.swap_used as f64 / mm.swap_total as f64 * 100.0) as u16
+        } else {
+            0
+        };
         (mm.swap_used, mm.swap_total, pct)
-    } else { (0, 0, 0) };
+    } else {
+        (0, 0, 0)
+    };
 
     let g = Gauge::default()
         .block(Block::default().borders(Borders::ALL).title("Swap"))
@@ -20,4 +26,4 @@ pub fn draw_swap(f: &mut ratatui::Frame<'_>, area: Rect, m: Option<&Metrics>) {
         .percent(pct)
         .label(format!("{} / {}", human(used), human(total)));
     f.render_widget(g, area);
-}
+}

socktop/src/ui/theme.rs

@@ -0,0 +1,8 @@
+//! Shared UI theme constants.
+
+use ratatui::style::Color;
+
+// Scrollbar colors (same look as before)
+pub const SB_ARROW: Color = Color::Rgb(170, 170, 180);
+pub const SB_TRACK: Color = Color::Rgb(170, 170, 180);
+pub const SB_THUMB: Color = Color::Rgb(170, 170, 180);

socktop/src/ui/util.rs

@@ -3,31 +3,49 @@
 pub fn human(b: u64) -> String {
     const K: f64 = 1024.0;
     let b = b as f64;
-    if b < K { return format!("{b:.0}B"); }
+    if b < K {
+        return format!("{b:.0}B");
+    }
     let kb = b / K;
-    if kb < K { return format!("{kb:.1}KB"); }
+    if kb < K {
+        return format!("{kb:.1}KB");
+    }
     let mb = kb / K;
-    if mb < K { return format!("{mb:.1}MB"); }
+    if mb < K {
+        return format!("{mb:.1}MB");
+    }
     let gb = mb / K;
-    if gb < K { return format!("{gb:.1}GB"); }
+    if gb < K {
+        return format!("{gb:.1}GB");
+    }
     let tb = gb / K;
     format!("{tb:.2}TB")
 }
 
 pub fn truncate_middle(s: &str, max: usize) -> String {
-    if s.len() <= max { return s.to_string(); }
-    if max <= 3 { return "...".into(); }
+    if s.len() <= max {
+        return s.to_string();
+    }
+    if max <= 3 {
+        return "...".into();
+    }
     let keep = max - 3;
     let left = keep / 2;
     let right = keep - left;
-    format!("{}...{}", &s[..left], &s[s.len()-right..])
+    format!("{}...{}", &s[..left], &s[s.len() - right..])
 }
 
 pub fn disk_icon(name: &str) -> &'static str {
     let n = name.to_ascii_lowercase();
-    if n.contains(':') { "🗄️" }
-    else if n.contains("nvme") { "⚡" }
-    else if n.starts_with("sd") { "💽" }
-    else if n.contains("overlay") { "📦" }
-    else { "🖴" }
-}
+    if n.contains(':') {
+        "🗄️"
+    } else if n.contains("nvme") {
+        "⚡"
+    } else if n.starts_with("sd") {
+        "💽"
+    } else if n.contains("overlay") {
+        "📦"
+    } else {
+        "🖴"
+    }
+}

socktop/src/ws.rs

@@ -1,15 +1,110 @@
 //! Minimal WebSocket client helpers for requesting metrics from the agent.
 
+use flate2::bufread::GzDecoder;
+use futures_util::{SinkExt, StreamExt};
+use prost::Message as _;
+use rustls::client::danger::{HandshakeSignatureValid, ServerCertVerified, ServerCertVerifier};
+use rustls::pki_types::{CertificateDer, ServerName, UnixTime};
+use rustls::{ClientConfig, RootCertStore};
+use rustls::{DigitallySignedStruct, SignatureScheme};
+use rustls_pemfile::Item;
+use std::io::Read;
+use std::{fs::File, io::BufReader, sync::Arc};
 use tokio::net::TcpStream;
-use tokio_tungstenite::{connect_async, tungstenite::Message, MaybeTlsStream, WebSocketStream};
+use tokio_tungstenite::{
+    connect_async, connect_async_tls_with_config, tungstenite::client::IntoClientRequest,
+    tungstenite::Message, Connector, MaybeTlsStream, WebSocketStream,
+};
+use url::Url;
 
-use crate::types::Metrics;
+use crate::types::{DiskInfo, Metrics, ProcessInfo, ProcessesPayload};
+
+mod pb {
+    // generated by build.rs
+    include!(concat!(env!("OUT_DIR"), "/socktop.rs"));
+}
 
 pub type WsStream = WebSocketStream<MaybeTlsStream<TcpStream>>;
 
 // Connect to the agent and return the WS stream
-pub async fn connect(url: &str) -> Result<WsStream, Box<dyn std::error::Error>> {
-    let (ws, _) = connect_async(url).await?;
+pub async fn connect(
+    url: &str,
+    tls_ca: Option<&str>,
+) -> Result<WsStream, Box<dyn std::error::Error>> {
+    let mut u = Url::parse(url)?;
+    if let Some(ca_path) = tls_ca {
+        if u.scheme() == "ws" {
+            let _ = u.set_scheme("wss");
+        }
+        return connect_with_ca(u.as_str(), ca_path).await;
+    }
+    let (ws, _) = connect_async(u.as_str()).await?;
+    Ok(ws)
+}
+
+async fn connect_with_ca(url: &str, ca_path: &str) -> Result<WsStream, Box<dyn std::error::Error>> {
+    let mut root = RootCertStore::empty();
+    let mut reader = BufReader::new(File::open(ca_path)?);
+    let mut der_certs = Vec::new();
+    while let Ok(Some(item)) = rustls_pemfile::read_one(&mut reader) {
+        if let Item::X509Certificate(der) = item {
+            der_certs.push(der);
+        }
+    }
+    root.add_parsable_certificates(der_certs);
+
+    let mut cfg = ClientConfig::builder()
+        .with_root_certificates(root)
+        .with_no_client_auth();
+
+    let req = url.into_client_request()?;
+    let verify_domain = std::env::var("SOCKTOP_VERIFY_NAME").ok().as_deref() == Some("1");
+    if !verify_domain {
+        #[derive(Debug)]
+        struct NoVerify;
+        impl ServerCertVerifier for NoVerify {
+            fn verify_server_cert(
+                &self,
+                _end_entity: &CertificateDer<'_>,
+                _intermediates: &[CertificateDer<'_>],
+                _server_name: &ServerName,
+                _ocsp_response: &[u8],
+                _now: UnixTime,
+            ) -> Result<ServerCertVerified, rustls::Error> {
+                Ok(ServerCertVerified::assertion())
+            }
+            fn verify_tls12_signature(
+                &self,
+                _message: &[u8],
+                _cert: &CertificateDer<'_>,
+                _dss: &DigitallySignedStruct,
+            ) -> Result<HandshakeSignatureValid, rustls::Error> {
+                Ok(HandshakeSignatureValid::assertion())
+            }
+            fn verify_tls13_signature(
+                &self,
+                _message: &[u8],
+                _cert: &CertificateDer<'_>,
+                _dss: &DigitallySignedStruct,
+            ) -> Result<HandshakeSignatureValid, rustls::Error> {
+                Ok(HandshakeSignatureValid::assertion())
+            }
+            fn supported_verify_schemes(&self) -> Vec<SignatureScheme> {
+                // Provide common schemes; not strictly needed for skipping but keeps API happy
+                vec![
+                    SignatureScheme::ECDSA_NISTP256_SHA256,
+                    SignatureScheme::ED25519,
+                    SignatureScheme::RSA_PSS_SHA256,
+                ]
+            }
+        }
+        cfg.dangerous().set_certificate_verifier(Arc::new(NoVerify));
+        eprintln!("socktop: hostname verification disabled (default). Use --verify-hostname to enable strict SAN checking.");
+    }
+    let cfg = Arc::new(cfg);
+    let (ws, _) =
+        connect_async_tls_with_config(req, None, verify_domain, Some(Connector::Rustls(cfg)))
+            .await?;
     Ok(ws)
 }
 
@@ -19,10 +114,97 @@ pub async fn request_metrics(ws: &mut WsStream) -> Option<Metrics> {
         return None;
     }
     match ws.next().await {
+        Some(Ok(Message::Binary(b))) => {
+            gunzip_to_string(&b).and_then(|s| serde_json::from_str::<Metrics>(&s).ok())
+        }
         Some(Ok(Message::Text(json))) => serde_json::from_str::<Metrics>(&json).ok(),
         _ => None,
     }
 }
 
-// Re-export SinkExt/StreamExt for call sites
-use futures_util::{SinkExt, StreamExt};
+// Decompress a gzip-compressed binary frame into a String.
+fn gunzip_to_string(bytes: &[u8]) -> Option<String> {
+    let mut dec = GzDecoder::new(bytes);
+    let mut out = String::new();
+    dec.read_to_string(&mut out).ok()?;
+    Some(out)
+}
+
+fn gunzip_to_vec(bytes: &[u8]) -> Option<Vec<u8>> {
+    let mut dec = GzDecoder::new(bytes);
+    let mut out = Vec::new();
+    dec.read_to_end(&mut out).ok()?;
+    Some(out)
+}
+
+fn is_gzip(bytes: &[u8]) -> bool {
+    bytes.len() >= 2 && bytes[0] == 0x1f && bytes[1] == 0x8b
+}
+// Suppress dead_code until these are wired into the app
+#[allow(dead_code)]
+pub enum Payload {
+    Metrics(Metrics),
+    Disks(Vec<DiskInfo>),
+    Processes(ProcessesPayload),
+}
+
+// Send a "get_disks" request and await a JSON Vec<DiskInfo>
+pub async fn request_disks(ws: &mut WsStream) -> Option<Vec<DiskInfo>> {
+    if ws.send(Message::Text("get_disks".into())).await.is_err() {
+        return None;
+    }
+    match ws.next().await {
+        Some(Ok(Message::Binary(b))) => {
+            gunzip_to_string(&b).and_then(|s| serde_json::from_str::<Vec<DiskInfo>>(&s).ok())
+        }
+        Some(Ok(Message::Text(json))) => serde_json::from_str::<Vec<DiskInfo>>(&json).ok(),
+        _ => None,
+    }
+}
+
+// Send a "get_processes" request and await a ProcessesPayload decoded from protobuf (binary, may be gzipped)
+pub async fn request_processes(ws: &mut WsStream) -> Option<ProcessesPayload> {
+    if ws
+        .send(Message::Text("get_processes".into()))
+        .await
+        .is_err()
+    {
+        return None;
+    }
+    match ws.next().await {
+        Some(Ok(Message::Binary(b))) => {
+            let gz = is_gzip(&b);
+            let data = if gz { gunzip_to_vec(&b)? } else { b };
+            match pb::Processes::decode(data.as_slice()) {
+                Ok(pb) => {
+                    let rows: Vec<ProcessInfo> = pb
+                        .rows
+                        .into_iter()
+                        .map(|p: pb::Process| ProcessInfo {
+                            pid: p.pid,
+                            name: p.name,
+                            cpu_usage: p.cpu_usage,
+                            mem_bytes: p.mem_bytes,
+                        })
+                        .collect();
+                    Some(ProcessesPayload {
+                        process_count: pb.process_count as usize,
+                        top_processes: rows,
+                    })
+                }
+                Err(e) => {
+                    if std::env::var("SOCKTOP_DEBUG").ok().as_deref() == Some("1") {
+                        eprintln!("protobuf decode failed: {e}");
+                    }
+                    // Fallback: maybe it's JSON (bytes already decompressed if gz)
+                    match String::from_utf8(data) {
+                        Ok(s) => serde_json::from_str::<ProcessesPayload>(&s).ok(),
+                        Err(_) => None,
+                    }
+                }
+            }
+        }
+        Some(Ok(Message::Text(json))) => serde_json::from_str::<ProcessesPayload>(&json).ok(),
+        _ => None,
+    }
+}

socktop/tests/cli_args.rs

@@ -0,0 +1,75 @@
+//! CLI arg parsing tests for socktop (client)
+use std::process::Command;
+
+// We test the parsing by invoking the binary with --help and ensuring the help mentions short and long flags.
+// Also directly test the parse_args function via a tiny helper in a doctest-like fashion using a small
+// reimplementation here kept in sync with main (compile-time test).
+
+#[test]
+fn test_help_mentions_short_and_long_flags() {
+    let output = Command::new(env!("CARGO_BIN_EXE_socktop"))
+        .arg("--help")
+        .output()
+        .expect("run socktop --help");
+    let text = format!(
+        "{}{}",
+        String::from_utf8_lossy(&output.stdout),
+        String::from_utf8_lossy(&output.stderr)
+    );
+    assert!(
+        text.contains("--tls-ca")
+            && text.contains("-t")
+            && text.contains("--profile")
+            && text.contains("-P"),
+        "help text missing expected flags (--tls-ca/-t, --profile/-P)\n{text}"
+    );
+}
+
+#[test]
+fn test_tlc_ca_arg_long_and_short_parsed() {
+    // Use --help combined with flags to avoid network and still exercise arg acceptance
+    let exe = env!("CARGO_BIN_EXE_socktop");
+    // Long form with help
+    let out = Command::new(exe)
+        .args(["--tls-ca", "/tmp/cert.pem", "--help"])
+        .output()
+        .expect("run socktop");
+    assert!(
+        out.status.success(),
+        "socktop --tls-ca … --help did not succeed"
+    );
+    let text = format!(
+        "{}{}",
+        String::from_utf8_lossy(&out.stdout),
+        String::from_utf8_lossy(&out.stderr)
+    );
+    assert!(text.contains("Usage:"));
+    // Short form with help
+    let out2 = Command::new(exe)
+        .args(["-t", "/tmp/cert.pem", "--help"])
+        .output()
+        .expect("run socktop");
+    assert!(out2.status.success(), "socktop -t … --help did not succeed");
+    let text2 = format!(
+        "{}{}",
+        String::from_utf8_lossy(&out2.stdout),
+        String::from_utf8_lossy(&out2.stderr)
+    );
+    assert!(text2.contains("Usage:"));
+
+    // Profile flags with help (should not error)
+    let out3 = Command::new(exe)
+        .args(["--profile", "dev", "--help"])
+        .output()
+        .expect("run socktop");
+    assert!(
+        out3.status.success(),
+        "socktop --profile dev --help did not succeed"
+    );
+    let text3 = format!(
+        "{}{}",
+        String::from_utf8_lossy(&out3.stdout),
+        String::from_utf8_lossy(&out3.stderr)
+    );
+    assert!(text3.contains("Usage:"));
+}

socktop/tests/profiles.rs

@@ -0,0 +1,118 @@
+//! Tests for profile load/save and resolution logic (non-interactive paths only)
+use std::fs;
+use std::sync::Mutex;
+
+// Global lock to serialize tests that mutate process-wide environment variables.
+static ENV_LOCK: Mutex<()> = Mutex::new(());
+
+#[allow(dead_code)] // touch crate
+fn touch() {
+    let _ = socktop::types::Metrics {
+        cpu_total: 0.0,
+        cpu_per_core: vec![],
+        mem_total: 0,
+        mem_used: 0,
+        swap_total: 0,
+        swap_used: 0,
+        process_count: None,
+        hostname: String::new(),
+        cpu_temp_c: None,
+        disks: vec![],
+        networks: vec![],
+        top_processes: vec![],
+        gpus: None,
+    };
+}
+
+// We re-import internal modules by copying minimal logic here because profiles.rs isn't public.
+// Instead of exposing internals, we simulate profile saving through CLI invocations.
+
+use std::process::Command;
+
+fn run_socktop(args: &[&str]) -> (bool, String) {
+    let exe = env!("CARGO_BIN_EXE_socktop");
+    let output = Command::new(exe).args(args).output().expect("run socktop");
+    let ok = output.status.success();
+    let text = format!(
+        "{}{}",
+        String::from_utf8_lossy(&output.stdout),
+        String::from_utf8_lossy(&output.stderr)
+    );
+    (ok, text)
+}
+
+fn config_dir() -> std::path::PathBuf {
+    if let Some(xdg) = std::env::var_os("XDG_CONFIG_HOME") {
+        std::path::PathBuf::from(xdg).join("socktop")
+    } else {
+        dirs_next::config_dir()
+            .unwrap_or_else(|| std::path::PathBuf::from("."))
+            .join("socktop")
+    }
+}
+
+fn profiles_path() -> std::path::PathBuf {
+    config_dir().join("profiles.json")
+}
+
+#[test]
+fn test_profile_created_on_first_use() {
+    let _guard = ENV_LOCK.lock().unwrap();
+    // Isolate config in a temp dir
+    let td = tempfile::tempdir().unwrap();
+    std::env::set_var("XDG_CONFIG_HOME", td.path());
+    // Ensure directory exists fresh
+    std::fs::create_dir_all(td.path().join("socktop")).unwrap();
+    let _ = fs::remove_file(profiles_path());
+    // Provide profile + url => should create profiles.json
+    let (_ok, _out) = run_socktop(&["--profile", "unittest", "ws://example:1/ws", "--dry-run"]);
+    // We pass --help to exit early after parsing (no network attempt)
+    let data = fs::read_to_string(profiles_path()).expect("profiles.json created");
+    assert!(
+        data.contains("unittest"),
+        "profiles.json missing profile entry: {data}"
+    );
+}
+
+#[test]
+fn test_profile_overwrite_only_when_changed() {
+    let _guard = ENV_LOCK.lock().unwrap();
+    let td = tempfile::tempdir().unwrap();
+    std::env::set_var("XDG_CONFIG_HOME", td.path());
+    std::fs::create_dir_all(td.path().join("socktop")).unwrap();
+    let _ = fs::remove_file(profiles_path());
+    // Initial create
+    let (_ok, _out) = run_socktop(&["--profile", "prod", "ws://one/ws", "--dry-run"]); // create
+    let first = fs::read_to_string(profiles_path()).unwrap();
+    // Re-run identical (should not duplicate or corrupt)
+    let (_ok2, _out2) = run_socktop(&["--profile", "prod", "ws://one/ws", "--dry-run"]); // identical
+    let second = fs::read_to_string(profiles_path()).unwrap();
+    assert_eq!(
+        first, second,
+        "Profile file changed despite identical input"
+    );
+    // Overwrite with different URL using --save (no prompt path)
+    let (_ok3, _out3) = run_socktop(&["--profile", "prod", "--save", "ws://two/ws", "--dry-run"]);
+    let third = fs::read_to_string(profiles_path()).unwrap();
+    assert!(third.contains("two"), "Updated URL not written: {third}");
+}
+
+#[test]
+fn test_profile_tls_ca_persisted() {
+    let _guard = ENV_LOCK.lock().unwrap();
+    let td = tempfile::tempdir().unwrap();
+    std::env::set_var("XDG_CONFIG_HOME", td.path());
+    std::fs::create_dir_all(td.path().join("socktop")).unwrap();
+    let _ = fs::remove_file(profiles_path());
+    let (_ok, _out) = run_socktop(&[
+        "--profile",
+        "secureX",
+        "--tls-ca",
+        "/tmp/cert.pem",
+        "wss://host/ws",
+        "--dry-run",
+    ]);
+    let data = fs::read_to_string(profiles_path()).unwrap();
+    assert!(data.contains("secureX"));
+    assert!(data.contains("cert.pem"));
+}

socktop/tests/ws_probe.rs

@@ -0,0 +1,29 @@
+use socktop::ws::{connect, request_metrics, request_processes};
+
+// Integration probe: only runs when SOCKTOP_WS is set to an agent WebSocket URL.
+// Example: SOCKTOP_WS=ws://127.0.0.1:3000/ws cargo test -p socktop --test ws_probe -- --nocapture
+#[tokio::test]
+async fn probe_ws_endpoints() {
+    // Gate the test to avoid CI failures when no agent is running.
+    let url = match std::env::var("SOCKTOP_WS") {
+        Ok(v) if !v.is_empty() => v,
+        _ => {
+            eprintln!(
+                "skipping ws_probe: set SOCKTOP_WS=ws://host:port/ws to run this integration test"
+            );
+            return;
+        }
+    };
+
+    // Optional pinned CA for WSS/self-signed setups
+    let tls_ca = std::env::var("SOCKTOP_TLS_CA").ok();
+    let mut ws = connect(&url, tls_ca.as_deref()).await.expect("connect ws");
+
+    // Should get fast metrics quickly
+    let m = request_metrics(&mut ws).await;
+    assert!(m.is_some(), "expected Metrics payload within timeout");
+
+    // Processes may be gzipped and a bit slower, but should arrive
+    let p = request_processes(&mut ws).await;
+    assert!(p.is_some(), "expected Processes payload within timeout");
+}

socktop_agent/Cargo.toml

@@ -1,17 +1,37 @@
 [package]
 name = "socktop_agent"
-version = "0.1.0"
+version = "0.1.3"
 authors = ["Jason Witty <jasonpwitty+socktop@proton.me>"]
 description = "Remote system monitor over WebSocket, TUI like top"
 edition = "2021"
+license = "MIT"
 
 [dependencies]
 tokio = { version = "1", features = ["full"] }
 axum = { version = "0.7", features = ["ws", "macros"] }
-sysinfo = "0.36.1"
+sysinfo = { version = "0.37", features = ["network", "disk", "component"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-futures = "0.3"
+flate2 = { version = "1", default-features = false, features = ["rust_backend"] }
 futures-util = "0.3.31"
 tracing = "0.1"
-tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+# nvml-wrapper removed (unused; GPU metrics via gfxinfo only now)
+gfxinfo = "0.1.2"
+once_cell = "1.19"
+axum-server = { version = "0.6", features = ["tls-rustls"] }
+rustls = "0.23"
+rustls-pemfile = "2.1"
+rcgen = "0.13"  # pure-Rust self-signed cert generation (replaces openssl vendored build)
+anyhow = "1"
+hostname = "0.3"
+prost = { workspace = true }
+time = { version = "0.3", default-features = false, features = ["formatting", "macros", "parsing" ] }
+
+[build-dependencies]
+prost-build = "0.13"
+tonic-build = { version = "0.12", default-features = false, optional = true }
+protoc-bin-vendored = "3"
+[dev-dependencies]
+assert_cmd = "2.0"
+tempfile = "3.10"

socktop_agent/build.rs

@@ -0,0 +1,14 @@
+fn main() {
+    // Vendored protoc for reproducible builds
+    let protoc = protoc_bin_vendored::protoc_bin_path().expect("protoc");
+    std::env::set_var("PROTOC", &protoc);
+
+    println!("cargo:rerun-if-changed=proto/processes.proto");
+
+    // Compile protobuf definitions for processes
+    let mut cfg = prost_build::Config::new();
+    cfg.out_dir(std::env::var("OUT_DIR").unwrap());
+    // Use local path (ensures file is inside published crate tarball)
+    cfg.compile_protos(&["proto/processes.proto"], &["proto"]) // relative to CARGO_MANIFEST_DIR
+        .expect("compile protos");
+}

socktop_agent/proto/processes.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+package socktop;
+
+// All running processes. Sorting is done client-side.
+message Processes {
+  uint64 process_count = 1;           // total processes in the system
+  repeated Process rows = 2;          // all processes
+}
+
+message Process {
+  uint32 pid = 1;
+  string name = 2;
+  float cpu_usage = 3;                // 0..100
+  uint64 mem_bytes = 4;               // RSS bytes
+}

socktop_agent/src/gpu.rs

@@ -0,0 +1,24 @@
+// gpu.rs
+use gfxinfo::active_gpu;
+
+#[derive(Debug, Clone, serde::Serialize)]
+pub struct GpuMetrics {
+    pub name: String,
+    pub utilization_gpu_pct: u32, // 0..100
+    pub mem_used_bytes: u64,
+    pub mem_total_bytes: u64,
+}
+
+pub fn collect_all_gpus() -> Result<Vec<GpuMetrics>, Box<dyn std::error::Error>> {
+    let gpu = active_gpu()?; // Use ? to unwrap Result
+    let info = gpu.info();
+
+    let metrics = GpuMetrics {
+        name: gpu.model().to_string(),
+        utilization_gpu_pct: info.load_pct() as u32,
+        mem_used_bytes: info.used_vram(),
+        mem_total_bytes: info.total_vram(),
+    };
+
+    Ok(vec![metrics])
+}

socktop_agent/src/main.rs

@@ -1,136 +1,93 @@
-//! socktop agent entrypoint: sets up sysinfo handles, launches a sampler,
-//! and serves a WebSocket endpoint at /ws.
+//! socktop agent entrypoint: sets up sysinfo handles and serves a WebSocket endpoint at /ws.
 
+mod gpu;
 mod metrics;
-mod sampler;
+mod proto;
+// sampler module removed (metrics now purely request-driven)
 mod state;
-mod ws;
 mod types;
+mod ws;
 
-use axum::{routing::get, Router};
-use std::{collections::HashMap, net::SocketAddr, sync::Arc, time::Duration, sync::atomic::AtomicUsize};
-use sysinfo::{
-    Components, CpuRefreshKind, Disks, MemoryRefreshKind, Networks, ProcessRefreshKind, RefreshKind,
-    System,
-};
-use tokio::sync::{Mutex, RwLock, Notify};
-use tracing_subscriber::EnvFilter;
+use axum::{http::StatusCode, routing::get, Router};
+use std::net::SocketAddr;
+use std::str::FromStr;
 
-use state::{AppState, SharedTotals};
-use sampler::spawn_sampler;
-use ws::ws_handler;
+mod tls;
+
+use state::AppState;
+
+fn arg_flag(name: &str) -> bool {
+    std::env::args().any(|a| a == name)
+}
+fn arg_value(name: &str) -> Option<String> {
+    let mut it = std::env::args();
+    while let Some(a) = it.next() {
+        if a == name {
+            return it.next();
+        }
+    }
+    None
+}
+
+// (tests moved to end of file to satisfy clippy::items_after_test_module)
 
 #[tokio::main]
-async fn main() {
+async fn main() -> anyhow::Result<()> {
+    tracing_subscriber::fmt::init();
 
-    // Init logging; configure with RUST_LOG (e.g., RUST_LOG=info).
-    tracing_subscriber::fmt()
-        .with_env_filter(EnvFilter::from_default_env())
-        .with_target(false)
-        .compact()
-        .init();
+    // Version flag (print and exit). Keep before heavy initialization.
+    if arg_flag("--version") || arg_flag("-V") {
+        println!("socktop_agent {}", env!("CARGO_PKG_VERSION"));
+        return Ok(());
+    }
 
-    // sysinfo build specifics (scopes what refresh_all() will touch internally)
-    let refresh_kind = RefreshKind::nothing()
-        .with_cpu(CpuRefreshKind::everything())
-        .with_memory(MemoryRefreshKind::everything())
-        .with_processes(ProcessRefreshKind::everything());
+    let state = AppState::new();
 
-    // Initialize sysinfo handles once and keep them alive
-    let mut sys = System::new_with_specifics(refresh_kind);
-    sys.refresh_all();
+    // No background samplers: metrics collected on-demand per websocket request.
 
-    let mut nets = Networks::new();
-    nets.refresh(true);
+    // Web app: route /ws to the websocket handler
+    async fn healthz() -> StatusCode {
+        println!("/healthz request");
+        StatusCode::OK
+    }
+    let app = Router::new()
+        .route("/ws", get(ws::ws_handler))
+        .route("/healthz", get(healthz))
+        .with_state(state.clone());
 
-    let mut components = Components::new();
-    components.refresh(true);
+    let enable_ssl =
+        arg_flag("--enableSSL") || std::env::var("SOCKTOP_ENABLE_SSL").ok().as_deref() == Some("1");
+    if enable_ssl {
+        // Port can be overridden by --port or SOCKTOP_PORT; default to 8443 when SSL
+        let port = arg_value("--port")
+            .or_else(|| arg_value("-p"))
+            .or_else(|| std::env::var("SOCKTOP_PORT").ok())
+            .and_then(|s| s.parse::<u16>().ok())
+            .unwrap_or(8443);
 
-    let mut disks = Disks::new();
-    disks.refresh(true);
+        let (cert_path, key_path) = tls::ensure_self_signed_cert()?;
+        let cfg = axum_server::tls_rustls::RustlsConfig::from_pem_file(cert_path, key_path).await?;
 
-    // Shared state across requests
-    let state = AppState {
-        sys: Arc::new(Mutex::new(sys)),
-        nets: Arc::new(Mutex::new(nets)),
-        net_totals: Arc::new(Mutex::new(HashMap::<String, (u64, u64)>::new())) as SharedTotals,
-        components: Arc::new(Mutex::new(components)),
-        disks: Arc::new(Mutex::new(disks)),
-        last_json: Arc::new(RwLock::new(String::new())),
-        // new: adaptive sampling controls
-        client_count: Arc::new(AtomicUsize::new(0)),
-        wake_sampler: Arc::new(Notify::new()),
-        auth_token: std::env::var("SOCKTOP_TOKEN").ok().filter(|s| !s.is_empty()),
-    };
-
-    // Start background sampler (adjust cadence as needed)
-    let _sampler = spawn_sampler(state.clone(), Duration::from_millis(500));
-
-    // Web app
-    let port = resolve_port();
-    let app = Router::new().route("/ws", get(ws_handler)).with_state(state);
+        let addr = SocketAddr::from_str(&format!("0.0.0.0:{port}"))?;
+        println!("socktop_agent: TLS enabled. Listening on wss://{addr}/ws");
+        axum_server::bind_rustls(addr, cfg)
+            .serve(app.into_make_service())
+            .await?;
+        return Ok(());
+    }
 
+    // Non-TLS HTTP/WS path
+    let port = arg_value("--port")
+        .or_else(|| arg_value("-p"))
+        .or_else(|| std::env::var("SOCKTOP_PORT").ok())
+        .and_then(|s| s.parse::<u16>().ok())
+        .unwrap_or(3000);
     let addr = SocketAddr::from(([0, 0, 0, 0], port));
-
-    //output to console
-    println!("Remote agent running at http://{}", addr);
-    println!("WebSocket endpoint: ws://{}/ws", addr);
-
-    //trace logging
-    tracing::info!("Remote agent running at http://{} (ws at /ws)", addr);
-    tracing::info!("WebSocket endpoint: ws://{}/ws", addr);
-
-    let listener = tokio::net::TcpListener::bind(addr).await.unwrap();
-    axum::serve(listener, app).await.unwrap();
-
-}
-
-// Resolve the listening port from CLI args/env with a 3000 default.
-// Supports: --port <PORT>, -p <PORT>, a bare numeric positional arg, or SOCKTOP_PORT.
-fn resolve_port() -> u16 {
-    const DEFAULT: u16 = 3000;
-
-    // Env takes precedence over positional, but is overridden by explicit flags if present.
-    if let Ok(s) = std::env::var("SOCKTOP_PORT") {
-        if let Ok(p) = s.parse::<u16>() {
-            if p != 0 {
-                return p;
-            }
-        }
-        eprintln!("Warning: invalid SOCKTOP_PORT='{}'; using default {}", s, DEFAULT);
-    }
-
-    let mut args = std::env::args().skip(1);
-    while let Some(arg) = args.next() {
-        match arg.as_str() {
-            "--port" | "-p" => {
-                if let Some(v) = args.next() {
-                    match v.parse::<u16>() {
-                        Ok(p) if p != 0 => return p,
-                        _ => {
-                            eprintln!("Invalid port '{}'; using default {}", v, DEFAULT);
-                            return DEFAULT;
-                        }
-                    }
-                } else {
-                    eprintln!("Missing value for {} ; using default {}", arg, DEFAULT);
-                    return DEFAULT;
-                }
-            }
-            "--help" | "-h" => {
-                println!("Usage: socktop_agent [--port <PORT>] [PORT]\n       SOCKTOP_PORT=<PORT> socktop_agent");
-                std::process::exit(0);
-            }
-            s => {
-                if let Ok(p) = s.parse::<u16>() {
-                    if p != 0 {
-                        return p;
-                    }
-                }
-            }
-        }
-    }
-
-    DEFAULT
+    println!("socktop_agent: Listening on ws://{addr}/ws");
+    axum_server::bind(addr)
+        .serve(app.into_make_service())
+        .await?;
+    Ok(())
 }
 
+// Unit tests for CLI parsing moved to `tests/port_parse.rs`.

socktop_agent/src/metrics.rs

@@ -1,128 +1,457 @@
-//! Metrics collection using sysinfo. Keeps sysinfo handles in AppState to
-//! avoid repeated allocations and allow efficient refreshes.
+//! Metrics collection using sysinfo for socktop_agent.
 
+use crate::gpu::collect_all_gpus;
 use crate::state::AppState;
-use crate::types::{DiskInfo, Metrics, NetworkInfo, ProcessInfo};
-use sysinfo::{Components, System};
+use crate::types::{DiskInfo, Metrics, NetworkInfo, ProcessInfo, ProcessesPayload};
+use once_cell::sync::OnceCell;
+#[cfg(target_os = "linux")]
+use std::collections::HashMap;
+#[cfg(target_os = "linux")]
+use std::fs;
+#[cfg(target_os = "linux")]
+use std::io;
+use std::sync::Mutex;
+use std::time::Duration as StdDuration;
+use std::time::{Duration, Instant};
+use sysinfo::{ProcessRefreshKind, ProcessesToUpdate};
+use tracing::warn;
 
-pub async fn collect_metrics(state: &AppState) -> Metrics {
-    // System (CPU/mem/proc)
+// Runtime toggles (read once)
+fn gpu_enabled() -> bool {
+    static ON: OnceCell<bool> = OnceCell::new();
+    *ON.get_or_init(|| {
+        std::env::var("SOCKTOP_AGENT_GPU")
+            .map(|v| v != "0")
+            .unwrap_or(true)
+    })
+}
+fn temp_enabled() -> bool {
+    static ON: OnceCell<bool> = OnceCell::new();
+    *ON.get_or_init(|| {
+        std::env::var("SOCKTOP_AGENT_TEMP")
+            .map(|v| v != "0")
+            .unwrap_or(true)
+    })
+}
+
+// Tiny TTL caches to avoid rescanning sensors every 500ms
+const TTL: Duration = Duration::from_millis(1500);
+struct TempCache {
+    at: Option<Instant>,
+    v: Option<f32>,
+}
+static TEMP: OnceCell<Mutex<TempCache>> = OnceCell::new();
+
+struct GpuCache {
+    at: Option<Instant>,
+    v: Option<Vec<crate::gpu::GpuMetrics>>,
+}
+static GPUC: OnceCell<Mutex<GpuCache>> = OnceCell::new();
+
+fn cached_temp() -> Option<f32> {
+    if !temp_enabled() {
+        return None;
+    }
+    let now = Instant::now();
+    let lock = TEMP.get_or_init(|| Mutex::new(TempCache { at: None, v: None }));
+    let mut c = lock.lock().ok()?;
+    if c.at.is_none_or(|t| now.duration_since(t) >= TTL) {
+        c.at = Some(now);
+        // caller will fill this; we just hold a slot
+        c.v = None;
+    }
+    c.v
+}
+
+fn set_temp(v: Option<f32>) {
+    if let Some(lock) = TEMP.get() {
+        if let Ok(mut c) = lock.lock() {
+            c.v = v;
+            c.at = Some(Instant::now());
+        }
+    }
+}
+
+fn cached_gpus() -> Option<Vec<crate::gpu::GpuMetrics>> {
+    if !gpu_enabled() {
+        return None;
+    }
+    let now = Instant::now();
+    let lock = GPUC.get_or_init(|| Mutex::new(GpuCache { at: None, v: None }));
+    let mut c = lock.lock().ok()?;
+    if c.at.is_none_or(|t| now.duration_since(t) >= TTL) {
+        // mark stale; caller will refresh
+        c.at = Some(now);
+        c.v = None;
+    }
+    c.v.clone()
+}
+
+fn set_gpus(v: Option<Vec<crate::gpu::GpuMetrics>>) {
+    if let Some(lock) = GPUC.get() {
+        if let Ok(mut c) = lock.lock() {
+            c.v = v.clone();
+            c.at = Some(Instant::now());
+        }
+    }
+}
+
+// Collect only fast-changing metrics (CPU/mem/net + optional temps/gpus).
+pub async fn collect_fast_metrics(state: &AppState) -> Metrics {
+    // TTL (ms) overridable via env, default 250ms
+    let ttl_ms: u64 = std::env::var("SOCKTOP_AGENT_METRICS_TTL_MS")
+        .ok()
+        .and_then(|v| v.parse().ok())
+        .unwrap_or(250);
+    let ttl = StdDuration::from_millis(ttl_ms);
+    {
+        let cache = state.cache_metrics.lock().await;
+        if cache.is_fresh(ttl) {
+            if let Some(c) = cache.take_clone() {
+                return c;
+            }
+        }
+    }
     let mut sys = state.sys.lock().await;
-    // Simple and safe — can be replaced by more granular refresh if desired:
-    // sys.refresh_cpu(); sys.refresh_memory(); sys.refresh_processes_specifics(...);
-    //sys.refresh_all();
-    //refresh all was found to use 2X CPU rather than individual refreshes
-    sys.refresh_cpu_all();
-    sys.refresh_memory();
-    sys.refresh_processes(sysinfo::ProcessesToUpdate::All, true);
+    if let Err(e) = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
+        sys.refresh_cpu_usage();
+        sys.refresh_memory();
+    })) {
+        warn!("sysinfo selective refresh panicked: {e:?}");
+    }
 
-    let hostname = System::host_name().unwrap_or_else(|| "unknown".into());
+    let hostname = state.hostname.clone();
+    let cpu_total = sys.global_cpu_usage();
+    let cpu_per_core: Vec<f32> = sys.cpus().iter().map(|c| c.cpu_usage()).collect();
+    let mem_total = sys.total_memory();
+    let mem_used = mem_total.saturating_sub(sys.available_memory());
+    let swap_total = sys.total_swap();
+    let swap_used = sys.used_swap();
+    drop(sys);
 
-    // Temps via a persistent Components handle
-    let mut components = state.components.lock().await;
-    components.refresh(true);
-    let cpu_temp_c = best_cpu_temp(&components);
+    // CPU temperature: only refresh sensors if cache is stale
+    let cpu_temp_c = if cached_temp().is_some() {
+        cached_temp()
+    } else if temp_enabled() {
+        let val = {
+            let mut components = state.components.lock().await;
+            components.refresh(false);
+            components.iter().find_map(|c| {
+                let l = c.label().to_ascii_lowercase();
+                if l.contains("cpu")
+                    || l.contains("package")
+                    || l.contains("tctl")
+                    || l.contains("tdie")
+                {
+                    c.temperature()
+                } else {
+                    None
+                }
+            })
+        };
+        set_temp(val);
+        val
+    } else {
+        None
+    };
 
-    // Disks via a persistent Disks handle
-    let mut disks_struct = state.disks.lock().await;
-    disks_struct.refresh(true);
-    // Filter anything with available == 0 (e.g., overlay/virtual)
-    let disks: Vec<DiskInfo> = disks_struct
-        .list()
+    // Networks
+    let networks: Vec<NetworkInfo> = {
+        let mut nets = state.networks.lock().await;
+        nets.refresh(false);
+        nets.iter()
+            .map(|(name, data)| NetworkInfo {
+                name: name.to_string(),
+                received: data.total_received(),
+                transmitted: data.total_transmitted(),
+            })
+            .collect()
+    };
+
+    // GPUs: if we already determined none exist, short-circuit (no repeated probing)
+    let gpus = if gpu_enabled() {
+        if state.gpu_checked.load(std::sync::atomic::Ordering::Acquire)
+            && !state.gpu_present.load(std::sync::atomic::Ordering::Relaxed)
+        {
+            None
+        } else if cached_gpus().is_some() {
+            cached_gpus()
+        } else {
+            let v = match collect_all_gpus() {
+                Ok(v) if !v.is_empty() => Some(v),
+                Ok(_) => None,
+                Err(e) => {
+                    warn!("gpu collection failed: {e}");
+                    None
+                }
+            };
+            // First probe records presence; subsequent calls rely on cache flags.
+            if !state
+                .gpu_checked
+                .swap(true, std::sync::atomic::Ordering::AcqRel)
+            {
+                if v.is_some() {
+                    state
+                        .gpu_present
+                        .store(true, std::sync::atomic::Ordering::Release);
+                } else {
+                    state
+                        .gpu_present
+                        .store(false, std::sync::atomic::Ordering::Release);
+                }
+            }
+            set_gpus(v.clone());
+            v
+        }
+    } else {
+        None
+    };
+
+    let metrics = Metrics {
+        cpu_total,
+        cpu_per_core,
+        mem_total,
+        mem_used,
+        swap_total,
+        swap_used,
+        hostname,
+        cpu_temp_c,
+        disks: Vec::new(),
+        networks,
+        top_processes: Vec::new(),
+        gpus,
+    };
+    {
+        let mut cache = state.cache_metrics.lock().await;
+        cache.set(metrics.clone());
+    }
+    metrics
+}
+
+// Cached disks
+pub async fn collect_disks(state: &AppState) -> Vec<DiskInfo> {
+    let ttl_ms: u64 = std::env::var("SOCKTOP_AGENT_DISKS_TTL_MS")
+        .ok()
+        .and_then(|v| v.parse().ok())
+        .unwrap_or(1_000);
+    let ttl = StdDuration::from_millis(ttl_ms);
+    {
+        let cache = state.cache_disks.lock().await;
+        if cache.is_fresh(ttl) {
+            if let Some(v) = cache.take_clone() {
+                return v;
+            }
+        }
+    }
+    let mut disks_list = state.disks.lock().await;
+    disks_list.refresh(false); // don't drop missing disks
+    let disks: Vec<DiskInfo> = disks_list
         .iter()
-        .filter(|d| d.available_space() > 0)
         .map(|d| DiskInfo {
-            name: d.name().to_string_lossy().to_string(),
+            name: d.name().to_string_lossy().into_owned(),
             total: d.total_space(),
             available: d.available_space(),
         })
         .collect();
+    {
+        let mut cache = state.cache_disks.lock().await;
+        cache.set(disks.clone());
+    }
+    disks
+}
 
-    // Networks: use a persistent Networks + rolling totals
-    let mut nets = state.nets.lock().await;
-    nets.refresh(true);
-    let mut totals = state.net_totals.lock().await;
-    let mut networks: Vec<NetworkInfo> = Vec::new();
-    for (name, data) in nets.iter() {
-        // sysinfo: received()/transmitted() are deltas since last refresh
-        let delta_rx = data.received();
-        let delta_tx = data.transmitted();
+// Linux-only helpers and implementation using /proc deltas for accurate CPU%.
+#[cfg(target_os = "linux")]
+#[inline]
+fn read_total_jiffies() -> io::Result<u64> {
+    // /proc/stat first line: "cpu  user nice system idle iowait irq softirq steal ..."
+    let s = fs::read_to_string("/proc/stat")?;
+    if let Some(line) = s.lines().next() {
+        let mut it = line.split_whitespace();
+        let _cpu = it.next(); // "cpu"
+        let mut sum: u64 = 0;
+        for tok in it.take(8) {
+            if let Ok(v) = tok.parse::<u64>() {
+                sum = sum.saturating_add(v);
+            }
+        }
+        return Ok(sum);
+    }
+    Err(io::Error::other("no cpu line"))
+}
 
-        let entry = totals.entry(name.clone()).or_insert((0, 0));
-        entry.0 = entry.0.saturating_add(delta_rx);
-        entry.1 = entry.1.saturating_add(delta_tx);
+#[cfg(target_os = "linux")]
+#[inline]
+fn read_proc_jiffies(pid: u32) -> Option<u64> {
+    let path = format!("/proc/{pid}/stat");
+    let s = fs::read_to_string(path).ok()?;
+    // Find the right parenthesis that terminates comm; everything after is space-separated fields starting at "state"
+    let rpar = s.rfind(')')?;
+    let after = s.get(rpar + 2..)?; // skip ") "
+    let mut it = after.split_whitespace();
+    // utime (14th field) is offset 11 from "state", stime (15th) is next
+    let utime = it.nth(11)?.parse::<u64>().ok()?;
+    let stime = it.next()?.parse::<u64>().ok()?;
+    Some(utime.saturating_add(stime))
+}
 
-        networks.push(NetworkInfo {
-            name: name.clone(),
-            received: entry.0,
-            transmitted: entry.1,
-        });
+/// Collect all processes (Linux): compute CPU% via /proc jiffies delta; sorting moved to client.
+#[cfg(target_os = "linux")]
+pub async fn collect_processes_all(state: &AppState) -> ProcessesPayload {
+    let ttl_ms: u64 = std::env::var("SOCKTOP_AGENT_PROCESSES_TTL_MS")
+        .ok()
+        .and_then(|v| v.parse().ok())
+        .unwrap_or(1_000);
+    let ttl = StdDuration::from_millis(ttl_ms);
+    {
+        let cache = state.cache_processes.lock().await;
+        if cache.is_fresh(ttl) {
+            if let Some(v) = cache.take_clone() {
+                return v;
+            }
+        }
+    }
+    // Reuse shared System to avoid reallocation; refresh processes fully.
+    let mut sys_guard = state.sys.lock().await;
+    let sys = &mut *sys_guard;
+    sys.refresh_processes_specifics(
+        ProcessesToUpdate::All,
+        false,
+        ProcessRefreshKind::everything().without_tasks(),
+    );
+
+    let total_count = sys.processes().len();
+
+    // Snapshot current per-pid jiffies
+    let mut current: HashMap<u32, u64> = HashMap::with_capacity(total_count);
+    for p in sys.processes().values() {
+        let pid = p.pid().as_u32();
+        if let Some(j) = read_proc_jiffies(pid) {
+            current.insert(pid, j);
+        }
+    }
+    let total_now = read_total_jiffies().unwrap_or(0);
+
+    // Compute deltas vs last sample
+    let (last_total, mut last_map) = {
+        #[cfg(target_os = "linux")]
+        {
+            let mut t = state.proc_cpu.lock().await;
+            let lt = t.last_total;
+            let lm = std::mem::take(&mut t.last_per_pid);
+            t.last_total = total_now;
+            t.last_per_pid = current.clone();
+            (lt, lm)
+        }
+        #[cfg(not(target_os = "linux"))]
+        {
+            let _: u64 = total_now; // silence unused warning
+            (0u64, HashMap::new())
+        }
+    };
+
+    // On first run or if total delta is tiny, report zeros
+    if last_total == 0 || total_now <= last_total {
+        let procs: Vec<ProcessInfo> = sys
+            .processes()
+            .values()
+            .map(|p| ProcessInfo {
+                pid: p.pid().as_u32(),
+                name: p.name().to_string_lossy().into_owned(),
+                cpu_usage: 0.0,
+                mem_bytes: p.memory(),
+            })
+            .collect();
+        return ProcessesPayload {
+            process_count: total_count,
+            top_processes: procs,
+        };
     }
 
-    // Normalize process CPU to 0..100 across all cores
-    let n_cpus = sys.cpus().len().max(1) as f32;
+    let dt = total_now.saturating_sub(last_total).max(1) as f32;
 
-    // Build process list
-    let mut procs: Vec<ProcessInfo> = sys
+    let procs: Vec<ProcessInfo> = sys
         .processes()
         .values()
-        .map(|p| ProcessInfo {
-            pid: p.pid().as_u32(),
-            name: p.name().to_string_lossy().to_string(),
-            cpu_usage: (p.cpu_usage() / n_cpus).min(100.0),
-            mem_bytes: p.memory(),
+        .map(|p| {
+            let pid = p.pid().as_u32();
+            let now = current.get(&pid).copied().unwrap_or(0);
+            let prev = last_map.remove(&pid).unwrap_or(0);
+            let du = now.saturating_sub(prev) as f32;
+            let cpu = ((du / dt) * 100.0).clamp(0.0, 100.0);
+            ProcessInfo {
+                pid,
+                name: p.name().to_string_lossy().into_owned(),
+                cpu_usage: cpu,
+                mem_bytes: p.memory(),
+            }
         })
         .collect();
 
-    // Partial select: get the top 20 by CPU without fully sorting the vector
-    const TOP_N: usize = 20;
-    if procs.len() > TOP_N {
-        // nth index is TOP_N-1 (0-based)
-        let nth = TOP_N - 1;
-        procs.select_nth_unstable_by(nth, |a, b| {
-            b.cpu_usage
-                .partial_cmp(&a.cpu_usage)
-                .unwrap_or(std::cmp::Ordering::Equal)
-        });
-        procs.truncate(TOP_N);
-        // Order those 20 nicely for display
-        procs.sort_by(|a, b| {
-            b.cpu_usage
-                .partial_cmp(&a.cpu_usage)
-                .unwrap_or(std::cmp::Ordering::Equal)
-        });
-    } else {
-        procs.sort_by(|a, b| {
-            b.cpu_usage
-                .partial_cmp(&a.cpu_usage)
-                .unwrap_or(std::cmp::Ordering::Equal)
-        });
-    }
-
-    Metrics {
-        cpu_total: sys.global_cpu_usage(),
-        cpu_per_core: sys.cpus().iter().map(|c| c.cpu_usage()).collect(),
-        mem_total: sys.total_memory(),
-        mem_used: sys.used_memory(),
-        swap_total: sys.total_swap(),
-        swap_used: sys.used_swap(),
-        process_count: sys.processes().len(),
-        hostname,
-        cpu_temp_c,
-        disks,
-        networks,
+    let payload = ProcessesPayload {
+        process_count: total_count,
         top_processes: procs,
+    };
+    {
+        let mut cache = state.cache_processes.lock().await;
+        cache.set(payload.clone());
     }
+    payload
 }
 
-// Pick the hottest CPU-like sensor (labels vary by platform)
-pub fn best_cpu_temp(components: &Components) -> Option<f32> {
-    components
-        .iter()
-        .filter(|c| {
-            let label = c.label().to_lowercase();
-            label.contains("cpu") || label.contains("package") || label.contains("tctl") || label.contains("tdie")
-        })
-        .filter_map(|c| c.temperature())
-        .max_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal))
-}
+/// Collect all processes (non-Linux): use sysinfo's internal CPU% by doing a double refresh.
+#[cfg(not(target_os = "linux"))]
+pub async fn collect_processes_all(state: &AppState) -> ProcessesPayload {
+    use tokio::time::sleep;
+    let ttl_ms: u64 = std::env::var("SOCKTOP_AGENT_PROCESSES_TTL_MS")
+        .ok()
+        .and_then(|v| v.parse().ok())
+        .unwrap_or(1_000);
+    let ttl = StdDuration::from_millis(ttl_ms);
+    {
+        let cache = state.cache_processes.lock().await;
+        if cache.is_fresh(ttl) {
+            if let Some(v) = cache.take_clone() {
+                return v;
+            }
+        }
+    }
+    {
+        let mut sys = state.sys.lock().await;
+        sys.refresh_processes_specifics(
+            ProcessesToUpdate::All,
+            false,
+            ProcessRefreshKind::everything().without_tasks(),
+        );
+    }
+    // Release lock during sleep interval
+    sleep(Duration::from_millis(250)).await;
+    {
+        let mut sys = state.sys.lock().await;
+        sys.refresh_processes_specifics(
+            ProcessesToUpdate::All,
+            false,
+            ProcessRefreshKind::everything().without_tasks(),
+        );
+        let total_count = sys.processes().len();
+        let procs: Vec<ProcessInfo> = sys
+            .processes()
+            .values()
+            .map(|p| ProcessInfo {
+                pid: p.pid().as_u32(),
+                name: p.name().to_string_lossy().into_owned(),
+                cpu_usage: p.cpu_usage(),
+                mem_bytes: p.memory(),
+            })
+            .collect();
+        let payload = ProcessesPayload {
+            process_count: total_count,
+            top_processes: procs,
+        };
+        {
+            let mut cache = state.cache_processes.lock().await;
+            cache.set(payload.clone());
+        }
+        payload
+    }
+}

socktop_agent/src/proto.rs

@@ -1,32 +1,5 @@
-use serde::{Deserialize, Serialize};
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct Metrics {
-    pub ts_unix_ms: i64,
-    pub host: String,
-    pub uptime_secs: u64,
-    pub cpu_overall: f32,
-    pub cpu_per_core: Vec<f32>,
-    pub load_avg: (f64, f64, f64),
-    pub mem_total_mb: u64,
-    pub mem_used_mb: u64,
-    pub swap_total_mb: u64,
-    pub swap_used_mb: u64,
-    pub net_aggregate: NetTotals,
-    pub top_processes: Vec<Proc>,
+// Generated protobuf modules live under OUT_DIR; include them here.
+// This module will expose socktop::Processes and socktop::Process types.
+pub mod pb {
+    include!(concat!(env!("OUT_DIR"), "/socktop.rs"));
 }
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct NetTotals {
-    pub rx_bytes: u64,
-    pub tx_bytes: u64,
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct Proc {
-    pub pid: i32,
-    pub name: String,
-    pub cpu: f32,
-    pub mem_mb: u64,
-    pub status: String,
-}

socktop_agent/src/sampler.rs

@@ -1,36 +0,0 @@
-//! Background sampler: periodically collects metrics and updates a JSON cache,
-//! so WS replies are just a read of the cached string.
-
-use crate::metrics::collect_metrics;
-use crate::state::AppState;
-//use serde_json::to_string;
-use tokio::task::JoinHandle;
-use tokio::time::{Duration, interval, MissedTickBehavior};
-
-pub fn spawn_sampler(state: AppState, period: Duration) -> JoinHandle<()> {
-    tokio::spawn(async move {
-        let idle_period = Duration::from_secs(10);
-        loop {
-            let active = state.client_count.load(std::sync::atomic::Ordering::Relaxed) > 0;
-            let mut ticker = interval(if active { period } else { idle_period });
-            ticker.set_missed_tick_behavior(MissedTickBehavior::Skip);
-            ticker.tick().await;
-
-            if !active {
-                tokio::select! {
-                    _ = ticker.tick() => {},
-                    _ = state.wake_sampler.notified() => continue,
-                }
-            }
-
-            if let Ok(json) = async {
-                let m = collect_metrics(&state).await;
-                serde_json::to_string(&m)
-            }
-            .await
-            {
-                *state.last_json.write().await = json;
-            }
-        }
-    })
-}

socktop_agent/src/state.rs

@@ -1,30 +1,103 @@
 //! Shared agent state: sysinfo handles and hot JSON cache.
 
-use std::{collections::HashMap, sync::Arc};
-use std::sync::atomic::AtomicUsize;
+#[cfg(target_os = "linux")]
+use std::collections::HashMap;
+use std::sync::atomic::{AtomicBool, AtomicUsize};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
 use sysinfo::{Components, Disks, Networks, System};
-use tokio::sync::{Mutex, RwLock, Notify};
+use tokio::sync::Mutex;
 
 pub type SharedSystem = Arc<Mutex<System>>;
-pub type SharedNetworks = Arc<Mutex<Networks>>;
-pub type SharedTotals = Arc<Mutex<HashMap<String, (u64, u64)>>>;
 pub type SharedComponents = Arc<Mutex<Components>>;
 pub type SharedDisks = Arc<Mutex<Disks>>;
+pub type SharedNetworks = Arc<Mutex<Networks>>;
+
+#[cfg(target_os = "linux")]
+#[derive(Default)]
+pub struct ProcCpuTracker {
+    pub last_total: u64,
+    pub last_per_pid: HashMap<u32, u64>,
+}
 
 #[derive(Clone)]
 pub struct AppState {
-    // Persistent sysinfo handles
     pub sys: SharedSystem,
-    pub nets: SharedNetworks,
-    pub net_totals: SharedTotals, // iface -> (rx_total, tx_total)
     pub components: SharedComponents,
     pub disks: SharedDisks,
+    pub networks: SharedNetworks,
+    pub hostname: String,
 
-    // Last serialized JSON snapshot for fast WS responses
-    pub last_json: Arc<RwLock<String>>,
+    // For correct per-process CPU% using /proc deltas (Linux only path uses this tracker)
+    #[cfg(target_os = "linux")]
+    pub proc_cpu: Arc<Mutex<ProcCpuTracker>>,
 
-    // Adaptive sampling controls
+    // Connection tracking (to allow future idle sleeps if desired)
     pub client_count: Arc<AtomicUsize>,
-    pub wake_sampler: Arc<Notify>,
+
     pub auth_token: Option<String>,
-}
+    // GPU negative cache (probe once). gpu_checked=true after first attempt; gpu_present reflects result.
+    pub gpu_checked: Arc<AtomicBool>,
+    pub gpu_present: Arc<AtomicBool>,
+
+    // Lightweight on-demand caches (TTL based) to cap CPU under bursty polling.
+    pub cache_metrics: Arc<Mutex<CacheEntry<crate::types::Metrics>>>,
+    pub cache_disks: Arc<Mutex<CacheEntry<Vec<crate::types::DiskInfo>>>>,
+    pub cache_processes: Arc<Mutex<CacheEntry<crate::types::ProcessesPayload>>>,
+}
+
+#[derive(Clone, Debug)]
+pub struct CacheEntry<T> {
+    pub at: Option<Instant>,
+    pub value: Option<T>,
+}
+
+impl<T> CacheEntry<T> {
+    pub fn new() -> Self {
+        Self {
+            at: None,
+            value: None,
+        }
+    }
+    pub fn is_fresh(&self, ttl: Duration) -> bool {
+        self.at.is_some_and(|t| t.elapsed() < ttl) && self.value.is_some()
+    }
+    pub fn set(&mut self, v: T) {
+        self.value = Some(v);
+        self.at = Some(Instant::now());
+    }
+    pub fn take_clone(&self) -> Option<T>
+    where
+        T: Clone,
+    {
+        self.value.clone()
+    }
+}
+
+impl AppState {
+    pub fn new() -> Self {
+        let sys = System::new();
+        let components = Components::new_with_refreshed_list();
+        let disks = Disks::new_with_refreshed_list();
+        let networks = Networks::new_with_refreshed_list();
+
+        Self {
+            sys: Arc::new(Mutex::new(sys)),
+            components: Arc::new(Mutex::new(components)),
+            disks: Arc::new(Mutex::new(disks)),
+            networks: Arc::new(Mutex::new(networks)),
+            hostname: System::host_name().unwrap_or_else(|| "unknown".into()),
+            #[cfg(target_os = "linux")]
+            proc_cpu: Arc::new(Mutex::new(ProcCpuTracker::default())),
+            client_count: Arc::new(AtomicUsize::new(0)),
+            auth_token: std::env::var("SOCKTOP_TOKEN")
+                .ok()
+                .filter(|s| !s.is_empty()),
+            gpu_checked: Arc::new(AtomicBool::new(false)),
+            gpu_present: Arc::new(AtomicBool::new(false)),
+            cache_metrics: Arc::new(Mutex::new(CacheEntry::new())),
+            cache_disks: Arc::new(Mutex::new(CacheEntry::new())),
+            cache_processes: Arc::new(Mutex::new(CacheEntry::new())),
+        }
+    }
+}

socktop_agent/src/tls.rs

@@ -0,0 +1,91 @@
+use rcgen::{CertificateParams, DistinguishedName, DnType, IsCa, SanType};
+use std::{
+    fs,
+    io::Write,
+    net::{IpAddr, Ipv4Addr},
+    path::{Path, PathBuf},
+};
+use time::{Duration, OffsetDateTime};
+
+fn config_dir() -> PathBuf {
+    std::env::var_os("XDG_CONFIG_HOME")
+        .map(PathBuf::from)
+        .or_else(|| std::env::var_os("HOME").map(|h| Path::new(&h).join(".config")))
+        .unwrap_or_else(|| PathBuf::from("."))
+        .join("socktop_agent")
+        .join("tls")
+}
+
+pub fn cert_paths() -> (PathBuf, PathBuf) {
+    let dir = config_dir();
+    (dir.join("cert.pem"), dir.join("key.pem"))
+}
+
+pub fn ensure_self_signed_cert() -> anyhow::Result<(PathBuf, PathBuf)> {
+    let (cert_path, key_path) = cert_paths();
+    if cert_path.exists() && key_path.exists() {
+        return Ok((cert_path, key_path));
+    }
+    fs::create_dir_all(cert_path.parent().unwrap())?;
+
+    let hostname = hostname::get()
+        .ok()
+        .and_then(|s| s.into_string().ok())
+        .unwrap_or_else(|| "localhost".to_string());
+
+    let mut params = CertificateParams::new(vec![hostname.clone(), "localhost".into()])?;
+    params
+        .subject_alt_names
+        .push(SanType::IpAddress(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1))));
+    params.subject_alt_names.push(SanType::IpAddress(IpAddr::V6(
+        ::std::net::Ipv6Addr::LOCALHOST,
+    )));
+    params
+        .subject_alt_names
+        .push(SanType::IpAddress(IpAddr::V4(Ipv4Addr::UNSPECIFIED)));
+
+    // Allow operator to provide extra SANs (comma-separated), e.g. IPs or DNS names
+    if let Ok(extra) = std::env::var("SOCKTOP_AGENT_EXTRA_SANS") {
+        for raw in extra.split(',') {
+            let s = raw.trim();
+            if s.is_empty() {
+                continue;
+            }
+            if let Ok(ip) = s.parse::<IpAddr>() {
+                params.subject_alt_names.push(SanType::IpAddress(ip));
+            } else {
+                match s.to_string().try_into() {
+                    Ok(dns) => params.subject_alt_names.push(SanType::DnsName(dns)),
+                    Err(_) => eprintln!("socktop_agent: ignoring invalid SAN entry: {s}"),
+                }
+            }
+        }
+    }
+
+    let mut dn = DistinguishedName::new();
+    dn.push(DnType::CommonName, hostname.clone());
+    params.distinguished_name = dn;
+    params.is_ca = IsCa::NoCa;
+    // Dynamic validity: start slightly in the past to avoid clock skew issues, end ~397 days later
+    let now = OffsetDateTime::now_utc();
+    params.not_before = now - Duration::minutes(5);
+    params.not_after = now + Duration::days(397);
+
+    // Generate key pair (default is ECDSA P256 SHA256)
+    let key_pair = rcgen::KeyPair::generate()?; // defaults to ECDSA P256 SHA256
+    let cert = params.self_signed(&key_pair)?;
+    let cert_pem = cert.pem();
+    let key_pem = key_pair.serialize_pem();
+
+    let mut f = fs::File::create(&cert_path)?;
+    f.write_all(cert_pem.as_bytes())?;
+    let mut k = fs::File::create(&key_path)?;
+    k.write_all(key_pem.as_bytes())?;
+
+    println!(
+        "socktop_agent: generated self-signed TLS certificate at {}",
+        cert_path.display()
+    );
+    println!("socktop_agent: private key at {}", key_path.display());
+    Ok((cert_path, key_path))
+}

socktop_agent/src/types.rs

@@ -1,9 +1,24 @@
 //! Data types sent to the client over WebSocket.
 //! Keep this module minimal and stable — it defines the wire format.
 
+use crate::gpu::GpuMetrics;
 use serde::Serialize;
 
-#[derive(Debug, Serialize, Clone)]
+#[derive(Debug, Clone, Serialize)]
+pub struct DiskInfo {
+    pub name: String,
+    pub total: u64,
+    pub available: u64,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct NetworkInfo {
+    pub name: String,
+    pub received: u64,
+    pub transmitted: u64,
+}
+
+#[derive(Debug, Clone, Serialize)]
 pub struct ProcessInfo {
     pub pid: u32,
     pub name: String,
@@ -11,22 +26,7 @@ pub struct ProcessInfo {
     pub mem_bytes: u64,
 }
 
-#[derive(Debug, Serialize, Clone)]
-pub struct DiskInfo {
-    pub name: String,
-    pub total: u64,
-    pub available: u64,
-}
-
-#[derive(Debug, Serialize, Clone)]
-pub struct NetworkInfo {
-    pub name: String,
-    // cumulative totals since the agent started (client should diff to get rates)
-    pub received: u64,
-    pub transmitted: u64,
-}
-
-#[derive(Debug, Serialize, Clone)]
+#[derive(Debug, Clone, Serialize)]
 pub struct Metrics {
     pub cpu_total: f32,
     pub cpu_per_core: Vec<f32>,
@@ -34,10 +34,16 @@ pub struct Metrics {
     pub mem_used: u64,
     pub swap_total: u64,
     pub swap_used: u64,
-    pub process_count: usize,
     pub hostname: String,
     pub cpu_temp_c: Option<f32>,
     pub disks: Vec<DiskInfo>,
     pub networks: Vec<NetworkInfo>,
     pub top_processes: Vec<ProcessInfo>,
-}
+    pub gpus: Option<Vec<GpuMetrics>>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ProcessesPayload {
+    pub process_count: usize,
+    pub top_processes: Vec<ProcessInfo>,
+}

socktop_agent/src/ws.rs

@@ -1,61 +1,81 @@
-//! WebSocket upgrade and per-connection handler. Serves cached JSON quickly.
+//! WebSocket upgrade and per-connection handler (request-driven).
 
 use axum::{
-    extract::{
-        ws::{Message, WebSocket, WebSocketUpgrade},
-        Query, State,
-    },
-    http::StatusCode,
-    response::{IntoResponse, Response},
+    extract::ws::{Message, WebSocket},
+    extract::{Query, State, WebSocketUpgrade},
+    response::Response,
 };
-use futures_util::stream::StreamExt;
-
-use crate::metrics::collect_metrics;
-use crate::state::AppState;
-
+use flate2::{write::GzEncoder, Compression};
+use futures_util::StreamExt;
 use std::collections::HashMap;
-use std::sync::atomic::Ordering;
+use std::io::Write;
+
+use crate::metrics::{collect_disks, collect_fast_metrics, collect_processes_all};
+use crate::proto::pb;
+use crate::state::AppState;
 
 pub async fn ws_handler(
     ws: WebSocketUpgrade,
     State(state): State<AppState>,
     Query(q): Query<HashMap<String, String>>,
 ) -> Response {
+    // optional auth
     if let Some(expected) = state.auth_token.as_ref() {
-        match q.get("token") {
-            Some(t) if t == expected => {}
-            _ => return StatusCode::UNAUTHORIZED.into_response(),
+        if q.get("token") != Some(expected) {
+            return ws.on_upgrade(|socket| async move {
+                let _ = socket.close().await;
+            });
         }
     }
     ws.on_upgrade(move |socket| handle_socket(socket, state))
 }
 
 async fn handle_socket(mut socket: WebSocket, state: AppState) {
-    // Bump client count on connect and wake the sampler.
-    state.client_count.fetch_add(1, Ordering::Relaxed);
-    state.wake_sampler.notify_waiters();
-
-    // Ensure we decrement on disconnect (drop).
-    struct ClientGuard(AppState);
-    impl Drop for ClientGuard {
-        fn drop(&mut self) {
-            self.0.client_count.fetch_sub(1, Ordering::Relaxed);
-            self.0.wake_sampler.notify_waiters();
-        }
-    }
-    let _guard = ClientGuard(state.clone());
-
+    state
+        .client_count
+        .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
     while let Some(Ok(msg)) = socket.next().await {
         match msg {
-            Message::Text(text) if text == "get_metrics" => {
-                // Serve the cached JSON quickly; if empty (cold start), collect once.
-                let cached = state.last_json.read().await.clone();
-                if !cached.is_empty() {
-                    let _ = socket.send(Message::Text(cached)).await;
+            Message::Text(ref text) if text == "get_metrics" => {
+                let m = collect_fast_metrics(&state).await;
+                let _ = send_json(&mut socket, &m).await;
+            }
+            Message::Text(ref text) if text == "get_disks" => {
+                let d = collect_disks(&state).await;
+                let _ = send_json(&mut socket, &d).await;
+            }
+            Message::Text(ref text) if text == "get_processes" => {
+                let payload = collect_processes_all(&state).await;
+                // Map to protobuf message
+                let rows: Vec<pb::Process> = payload
+                    .top_processes
+                    .into_iter()
+                    .map(|p| pb::Process {
+                        pid: p.pid,
+                        name: p.name,
+                        cpu_usage: p.cpu_usage,
+                        mem_bytes: p.mem_bytes,
+                    })
+                    .collect();
+                let pb = pb::Processes {
+                    process_count: payload.process_count as u64,
+                    rows,
+                };
+                let mut buf = Vec::with_capacity(8 * 1024);
+                if prost::Message::encode(&pb, &mut buf).is_err() {
+                    let _ = socket.send(Message::Close(None)).await;
                 } else {
-                    let metrics = collect_metrics(&state).await;
-                    if let Ok(js) = serde_json::to_string(&metrics) {
-                        let _ = socket.send(Message::Text(js)).await;
+                    // compress if large
+                    if buf.len() <= 768 {
+                        let _ = socket.send(Message::Binary(buf)).await;
+                    } else {
+                        let mut enc = GzEncoder::new(Vec::new(), Compression::fast());
+                        if enc.write_all(&buf).is_ok() {
+                            let bin = enc.finish().unwrap_or(buf);
+                            let _ = socket.send(Message::Binary(bin)).await;
+                        } else {
+                            let _ = socket.send(Message::Binary(buf)).await;
+                        }
                     }
                 }
             }
@@ -63,4 +83,19 @@ async fn handle_socket(mut socket: WebSocket, state: AppState) {
             _ => {}
         }
     }
-}
+    state
+        .client_count
+        .fetch_sub(1, std::sync::atomic::Ordering::Relaxed);
+}
+
+// Small, cheap gzip for larger payloads; send text for small.
+async fn send_json<T: serde::Serialize>(ws: &mut WebSocket, value: &T) -> Result<(), axum::Error> {
+    let json = serde_json::to_string(value).expect("serialize");
+    if json.len() <= 768 {
+        return ws.send(Message::Text(json)).await;
+    }
+    let mut enc = GzEncoder::new(Vec::new(), Compression::fast());
+    enc.write_all(json.as_bytes()).ok();
+    let bin = enc.finish().unwrap_or_else(|_| json.into_bytes());
+    ws.send(Message::Binary(bin)).await
+}

socktop_agent/tests/cli_args.rs

@@ -0,0 +1,28 @@
+//! CLI arg parsing tests for socktop_agent (server)
+use std::process::Command;
+
+#[test]
+fn test_help_and_port_short_long() {
+    // We verify port flags are accepted by ensuring the process starts (then we kill quickly).
+    // Use an unlikely port to avoid conflicts.
+    let exe = env!("CARGO_BIN_EXE_socktop_agent");
+
+    // TLS enabled with long --port
+    let mut child = Command::new(exe)
+        .args(["--enableSSL", "--port", "9555"])
+        .spawn()
+        .expect("spawn agent");
+    // Give it a moment to bind
+    std::thread::sleep(std::time::Duration::from_millis(150));
+    let _ = child.kill();
+    let _ = child.wait();
+
+    // TLS enabled with short -p
+    let mut child2 = Command::new(exe)
+        .args(["--enableSSL", "-p", "9556"])
+        .spawn()
+        .expect("spawn agent");
+    std::thread::sleep(std::time::Duration::from_millis(150));
+    let _ = child2.kill();
+    let _ = child2.wait();
+}

socktop_agent/tests/port_parse.rs

@@ -0,0 +1,40 @@
+//! Unit test for port parsing logic moved out of `main.rs`.
+
+fn parse_port<I: IntoIterator<Item = String>>(args: I, default_port: u16) -> u16 {
+    let mut it = args.into_iter();
+    let _ = it.next(); // program name
+    let mut long: Option<String> = None;
+    let mut short: Option<String> = None;
+    while let Some(a) = it.next() {
+        match a.as_str() {
+            "--port" => long = it.next(),
+            "-p" => short = it.next(),
+            _ if a.starts_with("--port=") => {
+                if let Some((_, v)) = a.split_once('=') {
+                    long = Some(v.to_string());
+                }
+            }
+            _ => {}
+        }
+    }
+    long.or(short)
+        .and_then(|s| s.parse::<u16>().ok())
+        .unwrap_or(default_port)
+}
+
+#[test]
+fn port_long_short_and_assign() {
+    assert_eq!(
+        parse_port(vec!["agent".into(), "--port".into(), "9001".into()], 8443),
+        9001
+    );
+    assert_eq!(
+        parse_port(vec!["agent".into(), "-p".into(), "9002".into()], 8443),
+        9002
+    );
+    assert_eq!(
+        parse_port(vec!["agent".into(), "--port=9003".into()], 8443),
+        9003
+    );
+    assert_eq!(parse_port(vec!["agent".into()], 8443), 8443);
+}

socktop_agent/tests/tls_cert_creation.rs

@@ -0,0 +1,59 @@
+use assert_cmd::prelude::*;
+use std::fs;
+use std::path::PathBuf;
+use std::process::Command;
+use std::time::Duration;
+use std::time::Instant;
+
+fn expected_paths(config_home: &std::path::Path) -> (PathBuf, PathBuf) {
+    let base = config_home.join("socktop_agent").join("tls");
+    (base.join("cert.pem"), base.join("key.pem"))
+}
+
+#[test]
+fn generates_self_signed_cert_and_key_in_xdg_path() {
+    // Create an isolated fake XDG_CONFIG_HOME
+    let tmpdir = tempfile::tempdir().expect("tempdir");
+    let xdg = tmpdir.path().to_path_buf();
+
+    // Run the agent once with --enableSSL, short timeout so it exits quickly when killed
+    let mut cmd = Command::cargo_bin("socktop_agent").expect("binary exists");
+    // Bind to an ephemeral port (-p 0) to avoid conflicts/flakes
+    cmd.env("XDG_CONFIG_HOME", &xdg)
+        .arg("--enableSSL")
+        .arg("-p")
+        .arg("0");
+
+    // Spawn the process and poll for cert generation
+    let mut child = cmd.spawn().expect("spawn agent");
+
+    // Poll up to ~3s for files to appear to avoid timing flakes
+    let (cert_path, key_path) = expected_paths(&xdg);
+    let start = Instant::now();
+    let timeout = Duration::from_millis(3000);
+    let interval = Duration::from_millis(50);
+    while start.elapsed() < timeout {
+        if cert_path.exists() && key_path.exists() {
+            break;
+        }
+        std::thread::sleep(interval);
+    }
+
+    // Terminate the process regardless
+    let _ = child.kill();
+    let _ = child.wait();
+
+    // Verify files exist at expected paths
+    assert!(
+        cert_path.exists(),
+        "cert not found at {}",
+        cert_path.display()
+    );
+    assert!(key_path.exists(), "key not found at {}", key_path.display());
+
+    // Also ensure they are non-empty
+    let cert_md = fs::metadata(&cert_path).expect("cert metadata");
+    let key_md = fs::metadata(&key_path).expect("key metadata");
+    assert!(cert_md.len() > 0, "cert is empty");
+    assert!(key_md.len() > 0, "key is empty");
+}