Merge pull request 'feat: experimental NVIDIA power control via RM ioctl interface' (#10) from feat/rm-power-control into main

Reviewed-on: #10

Makefile

@@ -0,0 +1,30 @@
+# NVCurve — developer convenience targets.
+#
+# End users don't need make: run ./install.sh (see README "Installation").
+
+UV  ?= uv
+NPM ?= npm
+
+.PHONY: help frontend frontend-dev install dev test clean
+
+help: ## Show available targets
+	@grep -E '^[a-zA-Z_-]+:.*?## ' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2}'
+
+frontend: ## Build the React frontend into frontend/dist
+	cd frontend && $(NPM) ci && $(NPM) run build
+
+frontend-dev: ## Run the Vite dev server (hot reload)
+	cd frontend && $(NPM) run dev
+
+install: ## Install nvcurve as a uv tool (builds frontend if missing/stale)
+	$(UV) tool install --force .
+
+dev: ## Create/refresh the dev environment (uv sync)
+	$(UV) sync
+
+test: ## Run the test suite
+	$(UV) run python tests/test_security.py
+	$(UV) run python tests/test_rm_power.py
+
+clean: ## Remove build artifacts
+	rm -rf frontend/dist frontend/node_modules

README.md

@@ -13,7 +13,7 @@ NVCurve brings MSI Afterburner-style per-point voltage-frequency curve control t
 
 > [!IMPORTANT]
 > **Blackwell GPU memory** — This is a specialized fork with extended memory offset support (up to +3000 MHz) for Blackwell GPUs (RTX 50-series). \
-> **Fan Controls** — There is an additional "Fans" tab to setup a customized fan curve. \
+> **Fan Controls** — There is an additional "Fans" tab to setup a customized fan curve, controlling all fans or individual fans. \
 > **Dashboard** — The default tab is an Dashboard with additional information (PCIe link speed, VBIOS information, Max Core Clock, Throttle Reason and much much more.) \
 > **Authentification** — For production deplyoment, I added authentification with bcrypt hashing to allow only one or multiple people to have access. \
 > Installing the pre-built PyPI package will NOT include these features. You must build from source.
@@ -37,20 +37,28 @@ NVCurve brings MSI Afterburner-style per-point voltage-frequency curve control t
 - **[uv](https://docs.astral.sh/uv/)** — Python package manager
 - **Root/sudo access** (required for GPU hardware interactions)
 
-## Installation from Source
+## Installation
+
+### One-liner
 
 ```bash
-git clone <this-repo-url>.git
+curl -fsSL https://gitea.zephyre.one/Pakobbix/nvcurve/raw/branch/main/install.sh | bash
+```
+
+The script checks prerequisites (installs `uv` if missing), clones the repo, and installs NVCurve — the React frontend is compiled automatically during the build.
+
+### From a clone
+
+```bash
+git clone https://gitea.zephyre.one/Pakobbix/nvcurve.git
 cd nvcurve
+./install.sh
+```
 
-# Build the React frontend
-cd frontend
-npm install
-npm run build
-cd ..
+### Direct from git (no clone, no script)
 
-# Install the Python package (includes bundled frontend)
-uv tool install .
+```bash
+uv tool install "git+https://gitea.zephyre.one/Pakobbix/nvcurve.git"
 ```
 
 After installation, verify hardware compatibility:
@@ -78,6 +86,20 @@ sudo nvcurve user remove alice   # remove a user
 
 Adding the first user enables authentication immediately; removing the last user disables it. See the [Usage Guide](docs/Usage-Guide.md#authentication-multi-user) for details.
 
+## TLS (HTTPS)
+
+The server speaks **plain HTTP by default**. For network access (e.g. behind a reverse proxy or on a LAN), you can enable TLS so the web UI, API, and WebSocket all run over HTTPS — the session cookie is then marked `Secure`.
+
+```bash
+# One-off (this server run only)
+nvcurve serve start --ssl-certfile /path/to/cert.pem --ssl-keyfile /path/to/key.pem
+
+# Persistent (stored in /etc/nvcurve/config.json; used by the daemon too)
+sudo nvcurve service configure --ssl-certfile /path/to/cert.pem --ssl-keyfile /path/to/key.pem
+```
+
+With TLS enabled the UI is at `https://<host>:8042` and the CLI switches to `https://` automatically. A self-signed certificate works for local use (the browser will warn); for multi-user setups use a certificate your browser trusts (e.g. via your internal CA or a reverse proxy).
+
 ## Systemd Service
 
 Install the daemon for automatic profile loading on boot and optional web server auto-start:
@@ -149,6 +171,10 @@ The daemon reads settings from `/etc/nvcurve/config.json`:
   "max_delta_khz": 3000000,
   "auto_snapshot": true,
   "max_snapshots": 20,
+  "ssl_certfile": null,
+  "ssl_keyfile": null,
+  "trusted_proxies": [],
+  "allow_api_shutdown": true,
   "auto_load_profiles": {
     "idx:0": "my_profile"
   }
@@ -160,9 +186,12 @@ The daemon reads settings from `/etc/nvcurve/config.json`:
 | `host` | Web server bind address (`0.0.0.0` for network access) |
 | `port` | Web server port (default `8042`) |
 | `auto_serve` | Auto-start web server on boot |
-| `max_delta_khz` | Safety cap for frequency offsets (default 3000 MHz) |
+| `max_delta_khz` | Safety cap for frequency offsets (default 3000 MHz). Enforced server-side; API clients cannot raise it per request |
 | `auto_snapshot` | Save snapshot before every write |
 | `max_snapshots` | Max snapshots to keep (`0` = unlimited) |
+| `ssl_certfile` / `ssl_keyfile` | TLS certificate/key — enables HTTPS when both are set (default: off) |
+| `trusted_proxies` | Proxy IPs whose `X-Forwarded-For` is trusted for the login lockout (e.g. `["127.0.0.1"]` for a local reverse proxy) |
+| `allow_api_shutdown` | Allow authenticated users to stop the server via `POST /api/shutdown` (set `false` on shared systems; use systemd instead) |
 | `auto_load_profiles` | Per-GPU profile to apply on boot (`{gpu_key: profile_name}`) |
 
 The GPU key can be a UUID, `pci:XXXX`, or `idx:N` fallback. Find your GPU key with `nvcurve gpus`.
@@ -179,10 +208,11 @@ The GPU key can be a UUID, `pci:XXXX`, or `idx:N` fallback. Find your GPU key wi
 ```bash
 cd nvcurve
 git pull
-cd frontend && npm run build && cd ..
-uv tool install .
+uv tool install --force .
 ```
 
+The frontend is rebuilt automatically if it is missing or older than the frontend sources. If you modified frontend code locally, run `make frontend` first (or `rm -rf frontend/dist`).
+
 If running as a systemd service:
 
 ```bash

docs/Installation.md

@@ -29,43 +29,52 @@ sudo pacman -S uv
 pip install uv
 ```
 
-## Installation from Source
+## Installation
 
-### Step 1: Clone the Repository
+### Option 1: One-liner (recommended)
 
 ```bash
-git clone <this-repo-url>.git
+curl -fsSL https://gitea.zephyre.one/Pakobbix/nvcurve/raw/branch/main/install.sh | bash
+```
+
+The script checks prerequisites (installs `uv` if missing), clones the repository, and installs NVCurve. The React frontend is compiled automatically during the build by a hatchling build hook (`hatch_build.py`).
+
+### Option 2: From a clone
+
+```bash
+git clone https://gitea.zephyre.one/Pakobbix/nvcurve.git
 cd nvcurve
+./install.sh
 ```
 
-### Step 2: Build the Frontend
-
-The frontend is a React + TypeScript + Vite application in the `frontend/` directory.
+Equivalent manual steps (what the script does):
 
 ```bash
-cd frontend
-npm install
-npm run build
-cd ..
+git clone https://gitea.zephyre.one/Pakobbix/nvcurve.git
+cd nvcurve
+uv tool install .   # frontend is built automatically if missing/stale
 ```
 
-This produces a `dist/` directory with the compiled static assets. The hatch build system bundles `frontend/dist` into the Python package.
-
-### Step 3: Install the Python Package
+### Option 3: Direct from git (no clone, no script)
 
 ```bash
-uv tool install .
+uv tool install "git+https://gitea.zephyre.one/Pakobbix/nvcurve.git"
 ```
 
-This installs `nvcurve` as a system-wide tool with the bundled frontend.
+To install a specific branch:
 
-### Step 4: Verify
+```bash
+uv tool install "git+https://gitea.zephyre.one/Pakobbix/nvcurve.git@<branch>"
+```
+
+### Verify
 
 ```bash
 nvcurve setup
 ```
 
 This performs four checks:
+
 1. **NvAPI function probe** — verifies all required functions resolve in your driver
 2. **Curve read** — reads and displays your current V/F curve as a baseline
 3. **Write-verify** — writes `+5 MHz` to a safe point, reads it back, and confirms the change
@@ -94,10 +103,11 @@ nvcurve serve start
 ```bash
 cd nvcurve
 git pull
-cd frontend && npm run build && cd ..
-uv tool install .
+uv tool install --force .
 ```
 
+The frontend is rebuilt automatically if it is missing or older than the frontend sources. If you modified frontend code locally, run `make frontend` first (or `rm -rf frontend/dist`).
+
 If running as a systemd service:
 
 ```bash
@@ -116,7 +126,7 @@ source ~/.local/bin/env  # or wherever uv installed
 
 ### Frontend not loading in the web UI
 
-Verify that `frontend/dist` exists and contains built assets. If the directory is empty or missing, rebuild with `npm run build` and reinstall with `uv tool install .`.
+Verify that the installed package contains the frontend. If `frontend/dist` is empty or missing, rebuild with `make frontend` (or `cd frontend && npm ci && npm run build`) and reinstall with `uv tool install --force .`.
 
 ### NvAPI functions not found
 

docs/Overview.md

@@ -17,7 +17,7 @@ NVCurve provides two ways to interact with your GPU:
 
 - **Per-Point Curve Editing** — Adjust the frequency offset for any individual voltage point on the V/F curve.
 - **Extended Memory Offset** — Memory clock offset up to +3000 MHz (Blackwell GPUs). Standard NVCurve caps at +1000 MHz.
-- **Fan Curve Control** — Custom temperature-to-fan-speed curves via NVML, adjustable through the web UI and savable in profiles.
+- **Fan Curve Control** — Custom temperature-to-fan-speed curves via NVML (all fans or individual fans), adjustable through the web UI and savable in profiles.
 - **Curve Flattening** — Select multiple points and flatten them to a common frequency using anchor-point targeting.
 - **Live Monitoring** — Track GPU voltage, clock speed, temperature, and power draw in real time via NvAPI and NVML.
 - **Profile Management** — Save, load, and switch between named profiles. Set a default profile that auto-applies on startup.
@@ -29,7 +29,7 @@ NVCurve provides two ways to interact with your GPU:
 NVCurve consists of two components:
 
 | Component | Description |
-|---|---|
+| --- | --- |
 | **Python Backend** | Talks directly to `libnvidia-api.so` (via ctypes) and `libnvidia-ml.so` to read and write GPU hardware state. Exposes functionality through a FastAPI REST + WebSocket server. |
 | **React Frontend** | Runs in the browser and communicates with the backend over HTTP and WebSockets. Handles curve visualization, point editing, live monitoring, and profile management. |
 

docs/Usage-Guide.md

@@ -84,6 +84,23 @@ The monitoring panel shows real-time GPU metrics:
 
 Data is streamed via WebSocket from the backend at a configurable poll interval (default: 1 second).
 
+### Performance Limits
+
+The Performance panel controls the board power limit and the memory clock offset. The power limit slider is bounded by the GPU's VBIOS minimum and maximum (shown at the slider ends); changes are applied on **Apply** and reset to the hardware default on **Reset**.
+
+#### Experimental NVIDIA power control
+
+On compatible drivers, an **Experimental NVIDIA power control** checkbox appears in the Performance panel. Enabling it switches power-limit application from the standard NVML call to an undocumented driver (RM) interface, which **permits caps below the VBIOS minimum, down to 30 W**. The native maximum still applies.
+
+> **Warning.** This uses an undocumented driver interface for *all* power limits, including resets. It may cause instability or stop working after a driver update. Enable it at your own risk. The option is clearly labelled with a red warning in the UI, and profiles saved while it is enabled are marked accordingly.
+
+Notes:
+
+- The checkbox only appears when the driver exposes a compatible RM power layout (detected with a read-only probe — no writes).
+- In this mode there is **no automatic fallback** to NVML: if the RM route fails, the error is reported rather than silently switching backends.
+- The mode is per-GPU and persisted across server restarts. Reset restores the default through the same route, so it can also clear a previously-set below-minimum cap.
+- The CLI reports availability via `nvcurve read --diag` ("Experimental RM power: available").
+
 ### Multi-GPU
 
 When multiple NVIDIA GPUs are detected, a GPU selector dropdown appears in the status bar. Switching GPUs resets pending edits, selection state, and monitoring for the new target.
@@ -145,6 +162,27 @@ Adding the first user **switches the server into authenticated mode immediately*
 - The user store file should stay root-owned and `0600` (the CLI enforces this).
 - The web UI and API are still only as safe as the network path to the server — bind to a trusted interface (`--host`) and/or firewall the port. Authentication protects against casual access, not a determined network attacker.
 - The `nvcurve user` commands and the user store require root; day-to-day sign-in does not.
+- The login lockout is keyed by client IP. Behind a reverse proxy all clients share the proxy's IP — set `trusted_proxies` in `/etc/nvcurve/config.json` (e.g. `["127.0.0.1"]`) so the lockout uses the real client IP from `X-Forwarded-For`. The header is only honoured for peers you list there (it is spoofable otherwise).
+- On shared systems consider setting `allow_api_shutdown: false` so users cannot stop the server via the API (manage it with systemd instead).
+- The frequency safety cap (`max_delta_khz`) is enforced by the server from its config; API clients cannot raise it per request. The CLI's `--max-delta` (root-only, direct hardware path) can still override it for a single write.
+
+## TLS (HTTPS)
+
+The server speaks **plain HTTP by default**. When you expose it beyond localhost, enable TLS so credentials and session cookies are not sent in cleartext:
+
+```bash
+# Persistent (stored in /etc/nvcurve/config.json, used by the daemon too)
+sudo nvcurve service configure --ssl-certfile /path/to/cert.pem --ssl-keyfile /path/to/key.pem
+
+# One-off
+nvcurve serve start --ssl-certfile /path/to/cert.pem --ssl-keyfile /path/to/key.pem
+```
+
+- Both files must be set for TLS to activate; the UI then lives at `https://<host>:8042` and the WebSocket upgrades to `wss://` automatically.
+- To disable TLS again: `sudo nvcurve service configure --no-ssl` (removes the certificate/key from the config).
+- The session cookie gets the `Secure` flag, so it is only sent over HTTPS.
+- A self-signed certificate is fine for a home LAN (the browser shows a warning); for multi-user setups use a certificate your browser trusts.
+- The CLI detects TLS from the config/runtime info and switches to `https://` automatically.
 
 ## CLI Reference
 
@@ -251,13 +289,14 @@ nvcurve service uninstall
 sudo nvcurve service configure --auto-serve
 sudo nvcurve service configure --no-auto-serve
 sudo nvcurve service configure --host 0.0.0.0 --port 8042
+sudo nvcurve service configure --ssl-certfile /path/to/cert.pem --ssl-keyfile /path/to/key.pem
 ```
 
 ## Configuration Files
 
 | File | Purpose |
 | --- | --- |
-| `/etc/nvcurve/config.json` | Persistent config (host, port, auto-serve, default profiles) |
+| `/etc/nvcurve/config.json` | Persistent config (host, port, auto-serve, TLS, safety cap, default profiles) |
 | `/etc/nvcurve/profiles/*.json` | Saved profiles |
 | `/var/cache/nvcurve/snapshots/` | Auto-saved snapshots before writes |
 | `/run/nvcurve.json` | Runtime server info (host, port, PID) |

frontend/src/api/client.ts

@@ -168,9 +168,9 @@ export const api = {
 
   /** Fan control */
   fans: (gpuIndex: number) => get<FanState>("/fans", gpuIndex),
-  updateFans: (curve: FanPoint[], gpuIndex: number) =>
-    post("/fans", { curve }, gpuIndex),
+  updateFans: (curve: FanPoint[], gpuIndex: number, fans?: number[] | null) =>
+    post("/fans", { curve, fans: fans ?? null }, gpuIndex),
   resetFans: (gpuIndex: number) => post("/fans/reset", undefined, gpuIndex),
-  setFanSpeed: (fanPct: number, gpuIndex: number) =>
-    post("/fans/speed", { fan_pct: fanPct }, gpuIndex),
+  setFanSpeed: (fanPct: number, gpuIndex: number, fan?: number | null) =>
+    post("/fans/speed", { fan_pct: fanPct, fan: fan ?? null }, gpuIndex),
 };

frontend/src/components/CurveEditor/CurveTooltip.tsx

@@ -1,12 +1,12 @@
-import { fmt } from '../../utils/units.js';
-import type { VFPoint } from '../../types.js';
+import { fmt } from "../../utils/units.js";
+import type { VFPoint } from "../../types.js";
 
 interface Props {
-  point: VFPoint;
-  /** Pending delta in kHz (from store), if any */
-  pendingDeltaKhz?: number;
-  /** True if this point is being held up by monotonicity enforcement */
-  isClamped?: boolean;
+    point: VFPoint;
+    /** Pending delta in kHz (from store), if any */
+    pendingDeltaKhz?: number;
+    /** True if this point is being held up by monotonicity enforcement */
+    isClamped?: boolean;
 }
 
 /**
@@ -14,49 +14,70 @@ interface Props {
  * SVG so it's never clipped by the SVG viewport.
  */
 export function CurveTooltip({ point, pendingDeltaKhz, isClamped }: Props) {
-  const hasPending = pendingDeltaKhz !== undefined;
-  const pendingMhz = hasPending ? pendingDeltaKhz! / 1000 : 0;
-  const deltaChange = hasPending ? pendingDeltaKhz! - point.delta_khz : 0;
-  const pendingEffMhz = hasPending ? point.freq_mhz + deltaChange / 1000 : null;
+    const hasPending = pendingDeltaKhz !== undefined;
+    const pendingMhz = hasPending ? pendingDeltaKhz! / 1000 : 0;
+    const deltaChange = hasPending ? pendingDeltaKhz! - point.delta_khz : 0;
+    const pendingEffMhz = hasPending
+        ? point.freq_mhz + deltaChange / 1000
+        : null;
 
-  return (
-    <div
-      className="absolute right-4 bottom-4 pointer-events-none z-50 w-[172px] bg-zinc-800 border border-zinc-700 rounded-md p-2 text-xs shadow-xl"
-    >
-      <div className="text-zinc-400 mb-1">Point {point.index}</div>
-      <div className="text-zinc-200">
-        <span className="text-zinc-400">Volt:   </span>{fmt.mv(point.volt_mv, 1)}
-      </div>
-      <div className="text-zinc-200">
-        <span className="text-zinc-400">Offset: </span>
-        <span className={point.delta_khz > 0 ? 'text-emerald-400' : point.delta_khz < 0 ? 'text-red-400' : 'text-zinc-400'}>
-          {point.delta_khz > 0 ? '+' : ''}{fmt.mhz(point.delta_mhz, 1)}
-        </span>
-      </div>
-      <div className="text-emerald-300 font-semibold">
-        <span className="text-zinc-400">Eff.:   </span>{fmt.mhz(point.freq_mhz, 0)}
-        {isClamped && <span className="text-amber-500 ml-1">⇡</span>}
-      </div>
-      {isClamped && (
-        <div className="text-amber-500/80 text-[10px] mt-0.5">
-          Clamped by lower-voltage point
-        </div>
-      )}
-      {hasPending && (
-        <>
-          <div className="border-t border-zinc-700 mt-1.5 pt-1.5">
+    return (
+        <div className="absolute right-4 bottom-4 pointer-events-none z-50 w-[172px] bg-zinc-800 border border-zinc-700 rounded-md p-2 text-xs shadow-xl">
+            <div className="text-zinc-400 mb-1">Point {point.index}</div>
             <div className="text-zinc-200">
-              <span className="text-zinc-400">Pending: </span>
-              <span className={pendingMhz > 0 ? 'text-cyan-400' : pendingMhz < 0 ? 'text-orange-400' : 'text-zinc-400'}>
-                {pendingMhz > 0 ? '+' : ''}{pendingMhz.toFixed(1)} MHz
-              </span>
+                <span className="text-zinc-400">Volt: </span>
+                {fmt.mv(point.volt_mv, 1)}
             </div>
-            <div className="text-cyan-300 font-semibold">
-              <span className="text-zinc-400">→ Eff.: </span>{fmt.mhz(pendingEffMhz, 0)}
+            <div className="text-zinc-200">
+                <span className="text-zinc-400">Offset: </span>
+                <span
+                    className={
+                        point.delta_khz > 0
+                            ? "text-emerald-400"
+                            : point.delta_khz < 0
+                              ? "text-red-400"
+                              : "text-zinc-400"
+                    }
+                >
+                    {point.delta_khz > 0 ? "+" : ""}
+                    {fmt.mhz(point.delta_mhz, 1)}
+                </span>
             </div>
-          </div>
-        </>
-      )}
-    </div>
-  );
+            <div className="text-emerald-300 font-semibold">
+                <span className="text-zinc-400">Eff.: </span>
+                {fmt.mhz(point.freq_mhz, 0)}
+                {isClamped && <span className="text-amber-500 ml-1">⇡</span>}
+            </div>
+            {isClamped && (
+                <div className="text-amber-500/80 text-[10px] mt-0.5">
+                    Clamped by lower-voltage point
+                </div>
+            )}
+            {hasPending && (
+                <>
+                    <div className="border-t border-zinc-700 mt-1.5 pt-1.5">
+                        <div className="text-zinc-200">
+                            <span className="text-zinc-400">Pending: </span>
+                            <span
+                                className={
+                                    pendingMhz > 0
+                                        ? "text-cyan-400"
+                                        : pendingMhz < 0
+                                          ? "text-orange-400"
+                                          : "text-zinc-400"
+                                }
+                            >
+                                {pendingMhz > 0 ? "+" : ""}
+                                {pendingMhz.toFixed(1)} MHz
+                            </span>
+                        </div>
+                        <div className="text-cyan-300 font-semibold">
+                            <span className="text-zinc-400">→ Eff.: </span>
+                            {fmt.mhz(pendingEffMhz, 0)}
+                        </div>
+                    </div>
+                </>
+            )}
+        </div>
+    );
 }

frontend/src/components/Fans/FanCurveEditor.tsx

@@ -2,7 +2,7 @@ import { useState, useEffect, useRef, useCallback } from "react";
 import { Check, X, RotateCcw, Plus } from "lucide-react";
 import { api } from "../../api/client.js";
 import { useCurveStore } from "../../store/curveStore.js";
-import type { FanPoint, FanState } from "../../types.js";
+import type { FanInfo, FanPoint, FanState } from "../../types.js";
 import { toast } from "sonner";
 import { ConfirmDialog } from "../common/ConfirmDialog.js";
 
@@ -44,6 +44,29 @@ function yToFan(y: number) {
   return Math.round(FAN_MAX - ((y - PAD.top) / PLOT_H) * (FAN_MAX - FAN_MIN));
 }
 
+function sameTargets(
+  a: number[] | null | undefined,
+  b: number[] | null | undefined,
+) {
+  if (a === null || a === undefined) return b === null || b === undefined;
+  if (b === null || b === undefined) return false;
+  if (a.length !== b.length) return false;
+  return a.every((v, i) => v === b[i]);
+}
+
+function fanLabel(targets: number[] | null): string {
+  return targets === null
+    ? "all fans"
+    : targets.map((i) => `Fan ${i + 1}`).join(", ");
+}
+
+const chipCls = (selected: boolean) =>
+  `px-2 py-0.5 rounded-full border text-xs font-medium transition-colors ${
+    selected
+      ? "bg-cyan-500/15 border-cyan-500/40 text-cyan-300"
+      : "bg-zinc-800 border-zinc-700 text-zinc-500 hover:text-zinc-300"
+  }`;
+
 export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
   const { selectedGpuIndex } = useCurveStore();
   const [fanState, setFanState] = useState<FanState | null>(null);
@@ -54,6 +77,9 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
   const [confirmApply, setConfirmApply] = useState(false);
   const [confirmReset, setConfirmReset] = useState(false);
   const [dragIdx, setDragIdx] = useState<number | null>(null);
+  // Fan selection: undefined = no pending change (follow server state),
+  // null = all fans, list = specific fan indices.
+  const [fanSel, setFanSel] = useState<number[] | null | undefined>(undefined);
   const svgRef = useRef<SVGSVGElement>(null);
 
   async function fetchFans() {
@@ -61,6 +87,7 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
       setLoading(true);
       const data = await api.fans(selectedGpuIndex);
       setFanState(data);
+      setFanSel(undefined);
       if (data.curve && data.curve.length > 0) {
         setPending(null);
       }
@@ -83,14 +110,41 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
   const curveActive = fanState?.curve_active ?? false;
   const isDefaults = !pending && !fanState?.curve;
 
+  const fanTargets =
+    fanSel === undefined ? (fanState?.fan_targets ?? null) : fanSel;
+  const fansChanged =
+    fanSel !== undefined && !sameTargets(fanSel, fanState?.fan_targets ?? null);
+  const fanList: FanInfo[] =
+    fanState?.fans && fanState.fans.length > 0
+      ? fanState.fans
+      : [{ index: 0, fan_pct: null }];
+
+  function toggleFan(idx: number) {
+    const numFans = fanState?.num_fans ?? 1;
+    let list: number[];
+    if (fanTargets === null) {
+      // Start from all fans, then drop the toggled one
+      list = Array.from({ length: numFans }, (_, i) => i).filter(
+        (i) => i !== idx,
+      );
+    } else {
+      list = fanTargets.includes(idx)
+        ? fanTargets.filter((i) => i !== idx)
+        : [...fanTargets, idx].sort((a, b) => a - b);
+    }
+    if (list.length === 0) return; // keep at least one fan selected
+    setFanSel(list.length === numFans ? null : list);
+  }
+
   async function handleApply() {
     const curveToApply = pending ?? fanState?.curve ?? defaultCurve();
     if (curveToApply.length < 2) return;
     setBusy(true);
     setError(null);
     try {
-      await api.updateFans(curveToApply, selectedGpuIndex);
+      await api.updateFans(curveToApply, selectedGpuIndex, fanTargets);
       setPending(null);
+      setFanSel(undefined);
       setConfirmApply(false);
       await fetchFans();
       onChanged?.();
@@ -109,6 +163,7 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
     try {
       await api.resetFans(selectedGpuIndex);
       setPending(null);
+      setFanSel(undefined);
       setConfirmReset(false);
       await fetchFans();
       onChanged?.();
@@ -251,9 +306,10 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
             <button
               onClick={() => {
                 setPending(null);
+                setFanSel(undefined);
                 setError(null);
               }}
-              disabled={!hasPending || busy}
+              disabled={(!hasPending && !fansChanged) || busy}
               className="flex items-center gap-1.5 px-2 py-1 rounded bg-zinc-800 hover:bg-zinc-700 text-zinc-300 text-xs transition-colors disabled:opacity-40 disabled:cursor-not-allowed"
             >
               <X size={12} />
@@ -270,6 +326,48 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
           </div>
         </div>
 
+        {/* Fan selection */}
+        <div className="px-4 py-2 border-b border-zinc-800/60 flex items-center gap-2 flex-wrap">
+          <span className="text-xs text-zinc-500 uppercase tracking-wider font-semibold">
+            Fans
+          </span>
+          {fanState?.num_fans === 0 ? (
+            <span className="text-xs text-zinc-600">
+              No fans available on this GPU
+            </span>
+          ) : (
+            <>
+              <button
+                onClick={() => setFanSel(null)}
+                className={chipCls(fanTargets === null)}
+                title="Control all fans"
+              >
+                All
+              </button>
+              {fanList.map((f) => (
+                <button
+                  key={f.index}
+                  onClick={() => toggleFan(f.index)}
+                  className={chipCls(
+                    fanTargets === null || fanTargets.includes(f.index),
+                  )}
+                  title={`Control Fan ${f.index + 1} with the curve`}
+                >
+                  Fan {f.index + 1}
+                  <span className="ml-1.5 font-mono text-[10px] opacity-80">
+                    {f.fan_pct !== null ? `${Math.round(f.fan_pct)}%` : "—"}
+                  </span>
+                </button>
+              ))}
+            </>
+          )}
+          {fansChanged && (
+            <span className="inline-flex items-center gap-1 px-2 py-0.5 rounded-full bg-cyan-500/15 border border-cyan-500/30 text-cyan-400 text-xs">
+              Fans: {fanLabel(fanTargets)}
+            </span>
+          )}
+        </div>
+
         {/* Error banner */}
         {error && (
           <div className="px-3 py-1.5 bg-red-900/40 border-b border-red-700 text-red-300 text-xs flex items-center justify-between">
@@ -557,13 +655,14 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
         {/* Info */}
         <div className="px-4 pb-3 text-[10px] text-zinc-600">
           {curveActive
-            ? "Fan curve is active. Server adjusts fan speed based on GPU temperature."
+            ? `Fan curve is active — controlling ${fanLabel(fanTargets)}. Server adjusts fan speed based on GPU temperature.`
             : isDefaults
               ? "These are default values. Click Apply to enable curve control, or edit points first."
               : "Apply a curve to enable automatic fan control based on temperature."}
           <span className="block mt-1 text-zinc-700">
             Drag points to adjust · click the chart to add a point · click the ✕
-            (chart or table) to remove one.
+            (chart or table) to remove one · pick which fans the curve controls
+            above.
           </span>
         </div>
       </div>
@@ -571,7 +670,7 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
       {confirmApply && (
         <ConfirmDialog
           message="Apply fan curve?"
-          detail="Fan control will switch to curve-based mode. The server will adjust fan speed based on GPU temperature."
+          detail={`Fan control will switch to curve-based mode for ${fanLabel(fanTargets)}. The server will adjust fan speed based on GPU temperature.`}
           confirmLabel="Apply"
           onConfirm={handleApply}
           onCancel={() => setConfirmApply(false)}

frontend/src/components/Limits/PerformancePanel.tsx

@@ -72,6 +72,21 @@ export function PerformancePanel() {
     }
   }
 
+  async function handleModeChange(enabled: boolean) {
+    setBusy(true);
+    try {
+      await api.updateLimits(
+        { power_cap_mode: enabled ? "ioctl" : "nvml" },
+        selectedGpuIndex,
+      );
+      await fetchLimits();
+    } catch (e: unknown) {
+      toast.error(e instanceof Error ? e.message : String(e));
+    } finally {
+      setBusy(false);
+    }
+  }
+
   if (loading && !limits) {
     return (
       <div className="bg-zinc-900 rounded-lg overflow-hidden flex flex-col animate-pulse">
@@ -158,12 +173,80 @@ export function PerformancePanel() {
         )}
 
         <div className="flex flex-col divide-y divide-zinc-800">
+          {/* ── Experimental NVIDIA power control ─────────────────────────── */}
+          {(limits.rm_power_supported || limits.power_cap_mode === "ioctl") && (
+            <div className="px-4 py-3 flex flex-col gap-2">
+              <label className="flex items-center gap-2 cursor-pointer select-none">
+                <input
+                  type="checkbox"
+                  checked={limits.power_cap_mode === "ioctl"}
+                  disabled={busy}
+                  onChange={(e) => handleModeChange(e.target.checked)}
+                  className="accent-red-500"
+                />
+                <span className="text-xs text-zinc-300">
+                  Experimental NVIDIA power control
+                </span>
+              </label>
+              {limits.rm_power_supported ? (
+                <div
+                  role="alert"
+                  className={
+                    "px-2.5 py-1.5 rounded border text-xs leading-relaxed " +
+                    (limits.power_cap_mode === "ioctl"
+                      ? "bg-red-950/80 border-red-500 text-red-300"
+                      : "bg-red-950/40 border-red-800 text-red-400")
+                  }
+                >
+                  <span className="font-bold">⚠ WARNING:</span> uses an
+                  undocumented driver interface for ALL power limits, including
+                  resets. Allows values below the VBIOS minimum (down to 30 W)
+                  and may cause instability or stop working after driver
+                  updates. Enable at your own risk. Based on the work of{" "}
+                  <a
+                    href="https://github.com/ilya-zlobintsev/LACT/pull/1205"
+                    target="_blank"
+                    rel="noopener noreferrer"
+                    className="underline hover:text-red-200"
+                  >
+                    panchovix
+                  </a>{" "}
+                  (LACT PR #1205).
+                </div>
+              ) : (
+                <div
+                  role="alert"
+                  className="px-2.5 py-1.5 rounded border border-red-500 bg-red-950/80 text-red-300 text-xs leading-relaxed"
+                >
+                  <span className="font-bold">
+                    ⚠ Interface not currently available.
+                  </span>
+                  The driver no longer exposes the RM power interface (it may
+                  have been updated). Experimental mode is still enabled, so
+                  power-limit changes will fail. Uncheck to switch back to the
+                  standard NVML mode.
+                </div>
+              )}
+            </div>
+          )}
+
           {/* ── Board Power Limit ─────────────────────────────────────────── */}
           <div className="px-4 py-4 flex flex-col gap-3">
             <div className="flex items-center justify-between">
-              <span className="text-xs text-zinc-500 uppercase tracking-wider">
-                Board Power Limit
-              </span>
+              <div className="flex items-center gap-2">
+                <span className="text-xs text-zinc-500 uppercase tracking-wider">
+                  Board Power Limit
+                </span>
+                {limits.power_cap_mode === "ioctl" &&
+                  limits.min_power_limit_w_native != null && (
+                    <span
+                      className="text-xs text-red-400/80 font-mono"
+                      title="Native VBIOS minimum — experimental mode allows lower"
+                    >
+                      VBIOS min {limits.min_power_limit_w_native} W
+                    </span>
+                  )}
+              </div>
               <div className="flex items-center gap-1.5">
                 <input
                   type="number"

frontend/src/components/Monitor/FanMonitor.tsx

@@ -47,6 +47,8 @@ export function FanMonitor({
 }: Props) {
   const fanHistory = pluck(history, "fan_pct");
   const tempHistory = pluck(history, "temp_c");
+  const fans = monitor?.fans ?? null;
+  const multiFan = fans !== null && fans.length > 1;
 
   const currentTemp = monitor?.temp_c ?? null;
   const targetFan = computeTargetFan(fanCurve, currentTemp);
@@ -68,13 +70,26 @@ export function FanMonitor({
           )}
         </div>
         <div className="flex flex-col gap-2 mt-1">
-          <GaugeCard
-            label="Fan Speed"
-            value={fmt.pct(monitor?.fan_pct)}
-            history={fanHistory}
-            color="#fb923c"
-            max={100}
-          />
+          {multiFan ? (
+            fans!.map((_, i) => (
+              <GaugeCard
+                key={i}
+                label={`Fan ${i + 1}`}
+                value={fmt.pct(fans![i])}
+                history={history.map((s) => s.fans?.[i] ?? s.fan_pct ?? 0)}
+                color="#fb923c"
+                max={100}
+              />
+            ))
+          ) : (
+            <GaugeCard
+              label="Fan Speed"
+              value={fmt.pct(monitor?.fan_pct)}
+              history={fanHistory}
+              color="#fb923c"
+              max={100}
+            />
+          )}
           <GaugeCard
             label="GPU Temp"
             value={fmt.celsius(monitor?.temp_c)}

frontend/src/components/Profiles/ProfilePanel.tsx

@@ -345,6 +345,11 @@ export function ProfilePanel({
                           {badges && (
                             <p className="text-xs text-zinc-500">{badges}</p>
                           )}
+                          {p.power_cap_mode === "ioctl" && (
+                            <p className="text-xs text-red-400 font-medium">
+                              ⚠ experimental power (below VBIOS min)
+                            </p>
+                          )}
                         </div>
                       </div>
 

frontend/src/types.ts

@@ -25,6 +25,7 @@ export interface MonitoringSample {
   temp_c: number | null;
   power_w: number | null;
   fan_pct: number | null;
+  fans: (number | null)[] | null;
   pstate: number | null;
   pstate_label: string | null;
   mem_used_bytes: number | null;
@@ -97,7 +98,11 @@ export interface LimitsState {
   power_limit_w: number | null;
   default_power_limit_w: number | null;
   min_power_limit_w: number | null;
+  min_power_limit_w_native: number | null;
   max_power_limit_w: number | null;
+  // "nvml" (default) or "ioctl" (experimental RM power control)
+  power_cap_mode: "nvml" | "ioctl";
+  rm_power_supported: boolean;
   // Clock offsets — current values
   gpc_offset_mhz: number | null;
   mem_offset_mhz: number | null;
@@ -111,13 +116,22 @@ export interface FanPoint {
   fan_pct: number;
 }
 
+export interface FanInfo {
+  index: number;
+  fan_pct: number | null;
+}
+
 export interface FanState {
   fan_pct: number | null;
+  fans: FanInfo[] | null;
+  num_fans: number | null;
   fan_mode: "auto" | "curve" | null;
   min_fan_pct: number | null;
   max_fan_pct: number | null;
   curve: FanPoint[] | null;
   curve_active: boolean;
+  // Fan indices controlled by the active curve; null = all fans.
+  fan_targets: number[] | null;
 }
 
 export interface ProfileData {
@@ -126,5 +140,8 @@ export interface ProfileData {
   curve_deltas: Record<string, number>;
   mem_offset_mhz: number | null;
   power_limit_w: number | null;
+  // "nvml" (default) or "ioctl" (experimental RM power control)
+  power_cap_mode: "nvml" | "ioctl" | null;
   fan_curve: FanPoint[] | null;
+  fan_targets: number[] | null;
 }

frontend/src/utils/curveHelpers.ts

@@ -1,4 +1,4 @@
-import type { VFPoint } from '../types.js';
+import type { VFPoint } from "../types.js";
 
 /**
  * Approximate reference frequency (MHz) for a point: effective − delta.
@@ -14,35 +14,37 @@ import type { VFPoint } from '../types.js';
  * useful as a faint reference line ("where this point would sit with no boost").
  */
 export function refBaseMhz(p: VFPoint): number {
-  return p.freq_mhz - p.delta_mhz;
+ return p.freq_mhz - p.delta_mhz;
 }
 
 /** Find which VF point the GPU is currently near based on voltage reading */
 export function findCurrentPoint(
-  points: VFPoint[],
-  voltage_mv: number | null,
+ points: VFPoint[],
+ voltage_mv: number | null,
 ): VFPoint | null {
-  if (voltage_mv == null || points.length === 0) return null;
-  return points.reduce((best, p) =>
-    Math.abs(p.volt_mv - voltage_mv) < Math.abs(best.volt_mv - voltage_mv) ? p : best,
-  );
+ if (voltage_mv == null || points.length === 0) return null;
+ return points.reduce((best, p) =>
+  Math.abs(p.volt_mv - voltage_mv) < Math.abs(best.volt_mv - voltage_mv)
+   ? p
+   : best,
+ );
 }
 
 /** Voltage domain extent, with padding */
 export function voltExtent(points: VFPoint[], padMv = 20): [number, number] {
-  if (points.length === 0) return [600, 1100];
-  const min = Math.min(...points.map((p) => p.volt_mv));
-  const max = Math.max(...points.map((p) => p.volt_mv));
-  return [min - padMv, max + padMv];
+ if (points.length === 0) return [600, 1100];
+ const min = Math.min(...points.map((p) => p.volt_mv));
+ const max = Math.max(...points.map((p) => p.volt_mv));
+ return [min - padMv, max + padMv];
 }
 
 /** Frequency domain extent for the effective (boosted) curve, with padding */
 export function freqExtent(points: VFPoint[], padMhz = 50): [number, number] {
-  if (points.length === 0) return [1000, 3000];
-  const allFreqs = points.flatMap((p) => [p.freq_mhz, refBaseMhz(p)]);
-  const min = Math.min(...allFreqs);
-  const max = Math.max(...points.map((p) => p.freq_mhz));
-  return [min - padMhz, max + padMhz];
+ if (points.length === 0) return [1000, 3000];
+ const allFreqs = points.flatMap((p) => [p.freq_mhz, refBaseMhz(p)]);
+ const min = Math.min(...allFreqs);
+ const max = Math.max(...points.map((p) => p.freq_mhz));
+ return [min - padMhz, max + padMhz];
 }
 
 /**
@@ -59,19 +61,19 @@ export function freqExtent(points: VFPoint[], padMhz = 50): [number, number] {
  * point 104 has +315 MHz → effective also 3907 MHz (clamped).
  */
 export function detectClampedPoints(points: VFPoint[]): Set<number> {
-  const clamped = new Set<number>();
-  let ceiling = -Infinity;
-  let ceilingOffset = -Infinity;
+ const clamped = new Set<number>();
+ let ceiling = -Infinity;
+ let ceilingOffset = -Infinity;
 
-  for (const p of points) {
-    if (p.freq_mhz <= ceiling && p.delta_khz < ceilingOffset) {
-      clamped.add(p.index);
-    }
-    if (p.freq_mhz > ceiling) {
-      ceiling = p.freq_mhz;
-      ceilingOffset = p.delta_khz;
-    }
+ for (const p of points) {
+  if (p.freq_mhz <= ceiling && p.delta_khz < ceilingOffset) {
+   clamped.add(p.index);
   }
+  if (p.freq_mhz > ceiling) {
+   ceiling = p.freq_mhz;
+   ceilingOffset = p.delta_khz;
+  }
+ }
 
-  return clamped;
+ return clamped;
 }

hatch_build.py

@@ -0,0 +1,74 @@
+"""Custom hatchling build hook: build the React frontend if it is missing or stale.
+
+This makes NVCurve installable with a single command, e.g.::
+
+    uv tool install "git+https://gitea.zephyre.one/Pakobbix/nvcurve.git"
+
+The hook runs inside the isolated build environment right before the wheel
+(or sdist) is assembled. If ``frontend/dist`` does not exist yet — or is older
+than the frontend sources — it compiles the frontend using the host's ``npm``
+(PATH is inherited from the environment).
+"""
+
+from __future__ import annotations
+
+import os
+import shutil
+import subprocess
+import sys
+
+from hatchling.builders.hooks.plugin.interface import BuildHookInterface
+
+# Frontend inputs that must be newer than dist/index.html to trigger a rebuild.
+_FRONTEND_INPUTS = (
+    "src",
+    "index.html",
+    "vite.config.ts",
+    "package.json",
+    "tsconfig.json",
+)
+
+
+class FrontendBuildHook(BuildHookInterface):
+    """Build ``frontend/dist`` with npm when it is missing or stale."""
+
+    PLUGIN_NAME = "custom"
+
+    def initialize(self, version: str, build_data: dict) -> None:
+        frontend = os.path.join(self.root, "frontend")
+        dist_index = os.path.join(frontend, "dist", "index.html")
+
+        if not self._needs_build(frontend, dist_index):
+            return
+
+        npm = shutil.which("npm")
+        if npm is None:
+            raise RuntimeError(
+                "npm not found on PATH. Node.js 18+ and npm are required to build "
+                "the NVCurve frontend. Install them and retry, or use install.sh "
+                "which checks prerequisites for you."
+            )
+
+        print(
+            "[nvcurve] frontend/dist missing or stale — building frontend with npm ...",
+            file=sys.stderr,
+        )
+        subprocess.run([npm, "ci", "--no-audit", "--no-fund"], cwd=frontend, check=True)
+        subprocess.run([npm, "run", "build"], cwd=frontend, check=True)
+
+    @staticmethod
+    def _needs_build(frontend: str, dist_index: str) -> bool:
+        if not os.path.isfile(dist_index):
+            return True
+        dist_mtime = os.path.getmtime(dist_index)
+        for name in _FRONTEND_INPUTS:
+            path = os.path.join(frontend, name)
+            if os.path.isfile(path):
+                if os.path.getmtime(path) > dist_mtime:
+                    return True
+            elif os.path.isdir(path):
+                for root, _dirs, files in os.walk(path):
+                    for file in files:
+                        if os.path.getmtime(os.path.join(root, file)) > dist_mtime:
+                            return True
+        return False

install.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+#
+# NVCurve single-command installer.
+#
+#   curl -fsSL https://gitea.zephyre.one/Pakobbix/nvcurve/raw/branch/main/install.sh | bash
+#
+# or from a local clone:
+#
+#   git clone https://gitea.zephyre.one/Pakobbix/nvcurve.git && cd nvcurve && ./install.sh
+#
+# The React frontend is compiled automatically during the Python build
+# (see hatch_build.py), so Node.js 18+ and npm must be available.
+#
+# Environment:
+#   NVCURVE_BRANCH  branch to install (default: main)
+
+set -euo pipefail
+
+REPO_URL="https://gitea.zephyre.one/Pakobbix/nvcurve.git"
+BRANCH="${NVCURVE_BRANCH:-main}"
+
+fail() {
+    echo "error: $*" >&2
+    exit 1
+}
+
+# --- prerequisites -----------------------------------------------------------
+command -v git >/dev/null 2>&1 ||
+    fail "git is required. Install it first."
+command -v node >/dev/null 2>&1 ||
+    fail "Node.js 18+ is required (e.g. 'sudo pacman -S nodejs npm' or 'sudo apt install nodejs npm')."
+command -v npm >/dev/null 2>&1 ||
+    fail "npm is required (usually installed together with Node.js)."
+
+if ! command -v uv >/dev/null 2>&1; then
+    echo "uv not found — installing it from https://astral.sh/uv ..."
+    curl -LsSf https://astral.sh/uv/install.sh | sh
+    export PATH="$HOME/.local/bin:$PATH"
+    command -v uv >/dev/null 2>&1 ||
+        fail "uv installation failed. Install uv manually: https://docs.astral.sh/uv/"
+fi
+
+# --- locate the source tree ---------------------------------------------------
+if [ -f pyproject.toml ] && [ -d frontend ]; then
+    src="$(pwd)"
+    echo "Installing from current directory: $src"
+else
+    tmp="$(mktemp -d)"
+    trap 'rm -rf "$tmp"' EXIT
+    echo "Cloning $REPO_URL (branch: $BRANCH) ..."
+    git clone --quiet --depth 1 --branch "$BRANCH" "$REPO_URL" "$tmp/nvcurve"
+    src="$tmp/nvcurve"
+fi
+
+# --- install -------------------------------------------------------------------
+# The frontend is built automatically by the build hook (hatch_build.py).
+uv tool install --force "$src"
+
+echo
+echo "NVCurve installed."
+echo "  Verify your GPU:  nvcurve setup"
+echo "  Start the web UI: nvcurve"

nvcurve/cli.py

@@ -38,7 +38,7 @@ import sys
 import time
 
 from .client import ApiError, NvCurveClient, ServerNotRunning
-from .config import Config, default_config
+from .config import Config, default_config, normalize_trusted_proxies, tls_enabled
 from .nvapi.constants import (
     CT_BASE,
     CT_POINTS,
@@ -405,6 +405,11 @@ def run_diagnostics(gpu, gpu_name, gpu_index: int = 0):
     print(f"  Default:  {fmt_w(def_w)}")
     if min_w is not None and max_w is not None:
         print(f"  Range:    {min_w} – {max_w} W")
+    if pwr.get("rm_power_supported"):
+        print(
+            "  Experimental RM power: available (opt-in via web UI or profile;"
+            " extends range to 30 W)"
+        )
 
 
 # ── Privilege / browser helpers ───────────────────────────────────────────────
@@ -472,6 +477,21 @@ _PERSISTENT_CONFIG_FILE = (
 )
 _DAEMON_SOCKET_PATH = "/run/nvcurve-daemon.sock"
 
+
+def _configured_max_delta() -> int:
+    """Frequency safety cap from the persistent config (built-in default fallback).
+
+    The operator-configured cap is authoritative for all direct-hardware
+    write paths (write, profile apply, verify) unless explicitly overridden
+    with --max-delta.
+    """
+    try:
+        with open(_PERSISTENT_CONFIG_FILE) as f:
+            return json.load(f).get("max_delta_khz", default_config.max_delta_khz)
+    except (FileNotFoundError, json.JSONDecodeError, OSError):
+        return default_config.max_delta_khz
+
+
 _ALLOWED_HOSTS = {"127.0.0.1", "::1", "localhost"}
 
 
@@ -548,12 +568,18 @@ def _discover_server_url(cfg: Config) -> str:
     1. /run/nvcurve.json      — runtime info written by the running server process
     2. /etc/nvcurve/config.json — persistent config written by `service install`
     3. Config defaults          — 127.0.0.1:8042
+
+    The scheme is https when TLS is configured (or reported by the running
+    server), http otherwise.
     """
+    scheme = "https" if tls_enabled(cfg) else "http"
+
     # 1. Runtime info (most accurate — reflects the actual running port)
     info = _read_server_info()
     if info:
         host = _safe_host(info["host"], cfg)
-        return f"http://{host}:{info['port']}"
+        s = "https" if info.get("tls") else scheme
+        return f"{s}://{host}:{info['port']}"
 
     # 2. Persistent config (survives reboots; written by `service install`)
     try:
@@ -561,12 +587,12 @@ def _discover_server_url(cfg: Config) -> str:
             data = json.load(f)
         host = _safe_host(data.get("host", cfg.host), cfg)
         port = data.get("port", cfg.port)
-        return f"http://{host}:{port}"
+        return f"{scheme}://{host}:{port}"
     except (FileNotFoundError, json.JSONDecodeError, KeyError):
         pass
 
     # 3. Hardcoded defaults
-    return f"http://{cfg.host}:{cfg.port}"
+    return f"{scheme}://{cfg.host}:{cfg.port}"
 
 
 # ── Subcommand handlers ───────────────────────────────────────────────────────
@@ -823,7 +849,7 @@ def cmd_write(args):
         }
 
     effective_max = (
-        max_delta_khz if max_delta_khz is not None else default_config.max_delta_khz
+        max_delta_khz if max_delta_khz is not None else _configured_max_delta()
     )
     errors = validate_write(point_deltas, effective_max)
     if errors:
@@ -864,6 +890,7 @@ def cmd_verify(args):
     from .hal.gpu import get_gpu
     from .hal.snapshot import save as snapshot_save
     from .hal.vfcurve import read_clock_offsets, write_offsets
+    from .safety import validate_write
 
     try:
         delta_khz = int(args.delta * 1000)
@@ -881,6 +908,13 @@ def cmd_verify(args):
 
     point_deltas = dict.fromkeys(points, delta_khz)
 
+    # Enforce the operator-configured safety cap (same as cmd_write).
+    errors = validate_write(point_deltas, _configured_max_delta())
+    if errors:
+        for e in errors:
+            print(f"Error: {e}", file=sys.stderr)
+        sys.exit(1)
+
     gpu, gpu_name = get_gpu(index=getattr(args, "gpu_index", 0))
 
     print("=== Write-Verify Cycle ===")
@@ -1178,12 +1212,33 @@ def cmd_profile(args):
             power_limit_w = None
             mem_offset_mhz = None
 
+        # Capture the GPU's power-cap mode: prefer the running server (most
+        # current), else fall back to the persisted per-GPU mode from config
+        # (so a profile saved while the server is down or auth is enabled
+        # still records the GPU's actual mode rather than assuming nvml).
+        power_cap_mode = "nvml"
+        try:
+            from .client import NvCurveClient
+
+            base = getattr(args, "server", None) or _discover_server_url(default_config)
+            limits = NvCurveClient(base=base, gpu_index=gpu_index).limits()
+            if limits.get("power_cap_mode") in ("nvml", "ioctl"):
+                power_cap_mode = limits["power_cap_mode"]
+        except Exception as exc:
+            log.debug("Could not read power-cap mode from server: %s", exc)
+            gpu_key = _gpu_stable_key_offline(gpu_index)
+            if gpu_key is not None:
+                persisted = default_config.power_cap_modes.get(gpu_key)
+                if persisted in ("nvml", "ioctl"):
+                    power_cap_mode = persisted
+
         data = ProfileData(
             name=args.name,
             gpu_name=gpu_name,
             curve_deltas=curve_deltas,
             mem_offset_mhz=mem_offset_mhz,
             power_limit_w=power_limit_w,
+            power_cap_mode=power_cap_mode,
         )
         filepath = save_profile(default_config.profile_dir, data)
         print(f"Saved profile '{args.name}' to {filepath}")
@@ -1220,7 +1275,8 @@ def cmd_profile(args):
                 errs.append(f"Mem offset: {msg}")
 
         if profile.power_limit_w is not None:
-            ok, msg = set_power_limit(profile.power_limit_w, gpu_index)
+            mode = profile.power_cap_mode or "nvml"
+            ok, msg = set_power_limit(profile.power_limit_w, gpu_index, mode)
             if not ok:
                 errs.append(f"Power limit: {msg}")
 
@@ -1233,7 +1289,7 @@ def cmd_profile(args):
                     file=sys.stderr,
                 )
                 sys.exit(1)
-            errors = validate_write(deltas, default_config.max_delta_khz)
+            errors = validate_write(deltas, _configured_max_delta())
             if errors:
                 errs.append("Curve: " + "; ".join(errors))
             else:
@@ -1571,6 +1627,10 @@ def cmd_service(args):
         port = getattr(args, "port", 8042)
         auto_serve = getattr(args, "auto_serve", False)
         persistent_cfg.update({"host": host, "port": port, "auto_serve": auto_serve})
+        if getattr(args, "ssl_certfile", None):
+            persistent_cfg["ssl_certfile"] = args.ssl_certfile
+        if getattr(args, "ssl_keyfile", None):
+            persistent_cfg["ssl_keyfile"] = args.ssl_keyfile
         try:
             with open(_PERSISTENT_CONFIG_FILE, "w") as f:
                 json.dump(persistent_cfg, f, indent=2)
@@ -1578,11 +1638,17 @@ def cmd_service(args):
             print(f"Failed to write {_PERSISTENT_CONFIG_FILE}: {exc}", file=sys.stderr)
             return
         print(f"Persistent config written to {_PERSISTENT_CONFIG_FILE}")
+        scheme = (
+            "https"
+            if persistent_cfg.get("ssl_certfile") and persistent_cfg.get("ssl_keyfile")
+            else "http"
+        )
         if auto_serve:
-            print(f"  Web server will auto-start on boot at {host}:{port}")
+            print(f"  Web server will auto-start on boot at {scheme}://{host}:{port}")
         else:
             print(
-                f"  Web server default: {host}:{port}  (start on demand: nvcurve serve start)"
+                f"  Web server default: {scheme}://{host}:{port}  "
+                "(start on demand: nvcurve serve start)"
             )
 
         try:
@@ -1706,12 +1772,14 @@ def cmd_service(args):
         auto_serve = pcfg.get("auto_serve", False)
         host = pcfg.get("host", "127.0.0.1")
         port = pcfg.get("port", 8042)
+        tls = bool(pcfg.get("ssl_certfile") and pcfg.get("ssl_keyfile"))
         print()
         print(f"web server auto-start: {'on' if auto_serve else 'off'}")
-        print(f"web server address:    {host}:{port}")
+        print(f"web server address:    {'https' if tls else 'http'}://{host}:{port}")
+        print(f"web server TLS:        {'on' if tls else 'off'}")
         print()
         print(
-            "Change with:  nvcurve service configure [--auto-serve|--no-auto-serve] [--host H] [--port P]"
+            "Change with:  nvcurve service configure [--auto-serve|--no-auto-serve] [--host H] [--port P] [--ssl-certfile C --ssl-keyfile K]"
         )
 
     elif action == "configure":
@@ -1736,6 +1804,13 @@ def cmd_service(args):
             pcfg["host"] = args.host
         if hasattr(args, "port") and args.port is not None:
             pcfg["port"] = args.port
+        if getattr(args, "ssl_certfile", None):
+            pcfg["ssl_certfile"] = args.ssl_certfile
+        if getattr(args, "ssl_keyfile", None):
+            pcfg["ssl_keyfile"] = args.ssl_keyfile
+        if getattr(args, "no_ssl", False):
+            pcfg.pop("ssl_certfile", None)
+            pcfg.pop("ssl_keyfile", None)
 
         try:
             with open(_PERSISTENT_CONFIG_FILE, "w") as f:
@@ -1747,6 +1822,9 @@ def cmd_service(args):
         print(f"  auto-serve: {'on' if pcfg.get('auto_serve', False) else 'off'}")
         print(f"  host:       {pcfg.get('host', '127.0.0.1')}")
         print(f"  port:       {pcfg.get('port', 8042)}")
+        print(
+            f"  TLS:        {'on' if pcfg.get('ssl_certfile') and pcfg.get('ssl_keyfile') else 'off'}"
+        )
 
         if os.path.exists(unit_path):
             try:
@@ -1766,12 +1844,28 @@ def _cmd_serve_start(args, cfg: Config, open_browser: bool = False) -> None:
     host = getattr(args, "host", cfg.host)
     port = getattr(args, "port", cfg.port)
 
+    # Optional TLS (CLI flags override the persistent config).
+    ssl_certfile = getattr(args, "ssl_certfile", None)
+    ssl_keyfile = getattr(args, "ssl_keyfile", None)
+    if ssl_certfile:
+        cfg.ssl_certfile = ssl_certfile
+    if ssl_keyfile:
+        cfg.ssl_keyfile = ssl_keyfile
+
     # --direct: skip daemon round-trip (used when the daemon itself spawns us).
     if getattr(args, "direct", False):
         require_root()
         try:
             with open(_SERVER_INFO_FILE, "w") as f:
-                json.dump({"pid": os.getpid(), "host": host, "port": port}, f)
+                json.dump(
+                    {
+                        "pid": os.getpid(),
+                        "host": host,
+                        "port": port,
+                        "tls": tls_enabled(cfg),
+                    },
+                    f,
+                )
         except OSError as exc:
             print(f"Failed to write {_SERVER_INFO_FILE}: {exc}", file=sys.stderr)
             return
@@ -1791,13 +1885,34 @@ def _cmd_serve_start(args, cfg: Config, open_browser: bool = False) -> None:
         return
 
     # Prefer daemon socket: no root required, daemon manages the server process.
-    resp = _daemon_send({"cmd": "serve_start", "host": host, "port": port})
+    # The daemon always binds the configured host/port (callers cannot choose
+    # the interface), so report the address from the daemon's response.
+    resp = _daemon_send({"cmd": "serve_start"})
     if resp is not None:
         if resp.get("ok"):
-            print(f"Web server starting (PID {resp['pid']}) at http://{host}:{port}")
+            rhost = resp.get("host", host)
+            rport = resp.get("port", port)
+            if (rhost, rport) != (host, port):
+                print(
+                    f"Note: daemon uses the configured bind address {rhost}:{rport} "
+                    "(change with: nvcurve service configure --host/--port)",
+                    file=sys.stderr,
+                )
+            if (ssl_certfile or ssl_keyfile) and not resp.get("tls"):
+                print(
+                    "Note: --ssl-certfile/--ssl-keyfile are ignored while the daemon "
+                    "manages the server — the daemon uses the TLS settings from "
+                    "/etc/nvcurve/config.json (set with: nvcurve service configure "
+                    "--ssl-certfile/--ssl-keyfile)",
+                    file=sys.stderr,
+                )
+            scheme = "https" if resp.get("tls") else "http"
+            print(
+                f"Web server starting (PID {resp['pid']}) at {scheme}://{rhost}:{rport}"
+            )
             if open_browser:
                 time.sleep(1.5)
-                _open_browser_as_user(f"http://{host}:{port}")
+                _open_browser_as_user(f"{scheme}://{rhost}:{rport}")
         else:
             print(f"Daemon: {resp.get('error')}", file=sys.stderr)
         return
@@ -1807,7 +1922,8 @@ def _cmd_serve_start(args, cfg: Config, open_browser: bool = False) -> None:
 
     info = _read_server_info()
     if info:
-        url = f"http://{info['host']}:{info['port']}"
+        scheme = "https" if info.get("tls") else "http"
+        url = f"{scheme}://{info['host']}:{info['port']}"
         print(f"Server is already running (PID {info['pid']}) at {url}.")
         if open_browser:
             _open_browser_as_user(url)
@@ -1827,6 +1943,10 @@ def _cmd_serve_start(args, cfg: Config, open_browser: bool = False) -> None:
             "--port",
             str(port),
         ]
+        if ssl_certfile:
+            cmd += ["--ssl-certfile", ssl_certfile]
+        if ssl_keyfile:
+            cmd += ["--ssl-keyfile", ssl_keyfile]
         if getattr(args, "gpu_index", 0):
             cmd += ["--gpu", str(args.gpu_index)]
         log_path = _log_file()
@@ -1846,7 +1966,15 @@ def _cmd_serve_start(args, cfg: Config, open_browser: bool = False) -> None:
     # Foreground mode — write info file so clients can discover host:port.
     try:
         with open(_SERVER_INFO_FILE, "w") as f:
-            json.dump({"pid": os.getpid(), "host": host, "port": port}, f)
+            json.dump(
+                {
+                    "pid": os.getpid(),
+                    "host": host,
+                    "port": port,
+                    "tls": tls_enabled(cfg),
+                },
+                f,
+            )
     except OSError as exc:
         print(f"Failed to write {_SERVER_INFO_FILE}: {exc}", file=sys.stderr)
         return
@@ -2056,6 +2184,12 @@ Examples:
         "--host", default="127.0.0.1", help="Bind address (default 127.0.0.1)"
     )
     p_start.add_argument("--port", type=int, default=8042, help="Port (default 8042)")
+    p_start.add_argument(
+        "--ssl-certfile", default=None, help="TLS certificate (enables HTTPS)"
+    )
+    p_start.add_argument(
+        "--ssl-keyfile", default=None, help="TLS private key (enables HTTPS)"
+    )
     p_start.add_argument(
         "--detach", "-d", action="store_true", help="Run in background"
     )
@@ -2090,6 +2224,16 @@ Examples:
         default=8042,
         help="Default web server port (stored in config)",
     )
+    p_install.add_argument(
+        "--ssl-certfile",
+        default=None,
+        help="TLS certificate (stored in config; enables HTTPS)",
+    )
+    p_install.add_argument(
+        "--ssl-keyfile",
+        default=None,
+        help="TLS private key (stored in config; enables HTTPS)",
+    )
 
     p_configure = s_svc.add_parser(
         "configure", help="Update config and restart daemon (escalates to root)"
@@ -2109,6 +2253,19 @@ Examples:
     )
     p_configure.add_argument("--host", default=None, help="Web server bind address")
     p_configure.add_argument("--port", type=int, default=None, help="Web server port")
+    p_configure.add_argument(
+        "--ssl-certfile",
+        default=None,
+        help="TLS certificate (stored in config; enables HTTPS)",
+    )
+    p_configure.add_argument(
+        "--ssl-keyfile", default=None, help="TLS private key (stored in config)"
+    )
+    p_configure.add_argument(
+        "--no-ssl",
+        action="store_true",
+        help="Disable TLS (remove certificate/key from config)",
+    )
 
     s_svc.add_parser("uninstall", help="Remove systemd service (escalates to root)")
     s_svc.add_parser("start", help="Start systemd service (escalates to root)")
@@ -2149,9 +2306,14 @@ def main():
                 "users_file",
                 "host",
                 "port",
+                "ssl_certfile",
+                "ssl_keyfile",
+                "allow_api_shutdown",
             ):
                 if key in data:
                     setattr(cfg, key, data[key])
+            if "trusted_proxies" in data:
+                cfg.trusted_proxies = normalize_trusted_proxies(data["trusted_proxies"])
             if "auto_load_profiles" in data:
                 # Keys are stable GPU identifiers (UUID, "pci:XXXX", or "idx:N")
                 cfg.auto_load_profiles = dict(data["auto_load_profiles"])
@@ -2161,6 +2323,14 @@ def main():
             if "fan_curves" in data:
                 # Per-GPU active fan curves, restored on server startup.
                 cfg.fan_curves = dict(data["fan_curves"])
+            if "power_cap_modes" in data:
+                # Per-GPU experimental power-cap mode. "nvml" is the default
+                # (the server treats it as unset); keep only valid values.
+                cfg.power_cap_modes = {
+                    str(k): str(v)
+                    for k, v in dict(data["power_cap_modes"]).items()
+                    if str(v) in ("nvml", "ioctl")
+                }
     except Exception as exc:
         log.debug("Could not load user config: %s", exc)
 

nvcurve/client.py

@@ -120,18 +120,13 @@ class NvCurveClient:
     def write_curve(
         self,
         deltas: dict[int, int],
-        max_delta_khz: int | None = None,
     ) -> dict:
-        body: dict = {"deltas": deltas}
-        if max_delta_khz is not None:
-            body["max_delta_khz"] = max_delta_khz
-        return self._post("/api/curve/write", body)
+        # The server enforces its configured safety cap; clients cannot
+        # override it per request.
+        return self._post("/api/curve/write", {"deltas": deltas})
 
-    def write_global(self, delta_khz: int, max_delta_khz: int | None = None) -> dict:
-        body: dict = {"delta_khz": delta_khz}
-        if max_delta_khz is not None:
-            body["max_delta_khz"] = max_delta_khz
-        return self._post("/api/curve/write/global", body)
+    def write_global(self, delta_khz: int) -> dict:
+        return self._post("/api/curve/write/global", {"delta_khz": delta_khz})
 
     def reset_curve(self) -> dict:
         return self._post("/api/curve/reset")
@@ -150,6 +145,9 @@ class NvCurveClient:
     def snapshots(self) -> list:
         return self._get("/api/snapshots")
 
+    def limits(self) -> dict:
+        return self._get("/api/limits")
+
     # ── Profiles ─────────────────────────────────────────────────────────────
 
     def profiles(self) -> dict:

nvcurve/config.py

@@ -17,6 +17,21 @@ class Config:
     host: str = "127.0.0.1"
     port: int = 8042
 
+    # Optional TLS: when both are set, the server serves HTTPS and the
+    # session cookie is marked Secure. Off by default (plain HTTP).
+    ssl_certfile: str | None = None
+    ssl_keyfile: str | None = None
+
+    # Proxy IPs (e.g. a reverse proxy on 127.0.0.1) whose X-Forwarded-For
+    # header is trusted for the login brute-force lockout. JSON array in
+    # config.json (a comma-separated string is also accepted and normalized).
+    # Without this, all proxied clients share the proxy's IP.
+    trusted_proxies: list[str] = field(default_factory=list)
+
+    # Allow any authenticated user to stop the server via POST /api/shutdown.
+    # Set false on shared systems; manage the service via systemd instead.
+    allow_api_shutdown: bool = True
+
     snapshot_dir: str = "/var/cache/nvcurve/snapshots"
     profile_dir: str = "/etc/nvcurve/profiles"
 
@@ -34,9 +49,38 @@ class Config:
     # curve applied via the UI survives server restarts (fan control itself is
     # volatile — the driver reverts to automatic mode on reboot).
     # Key = stable GPU identifier (same as auto_load_profiles).
-    # Value = list of {"temp_c": int, "fan_pct": int} sorted by temp_c.
-    fan_curves: dict[str, list] = field(default_factory=dict)
+    # Value = {"curve": [{"temp_c": int, "fan_pct": int}, ...] sorted by temp_c,
+    #          "fans": [fan indices] | None (None = all fans)}.
+    # Legacy entries (bare curve list) are migrated at load time.
+    fan_curves: dict[str, object] = field(default_factory=dict)
+
+    # Per-GPU power-cap mode: "nvml" (default, never stored) or "ioctl"
+    # (experimental RM power control — permits caps below the VBIOS minimum).
+    # Key = stable GPU identifier (same as auto_load_profiles).
+    power_cap_modes: dict[str, str] = field(default_factory=dict)
 
 
 # Module-level default config instance.
 default_config = Config()
+
+
+def tls_enabled(cfg: Config) -> bool:
+    """True when both TLS files are configured (server serves HTTPS)."""
+    return bool(cfg.ssl_certfile and cfg.ssl_keyfile)
+
+
+def normalize_trusted_proxies(value) -> list[str]:
+    """Normalize a trusted_proxies config value to a list of IP strings.
+
+    Accepts a JSON array (the documented format) or a comma-separated string
+    (tolerated for convenience). Normalizing matters because the server does
+    exact list membership tests — a raw string would degrade to substring
+    matching (e.g. "127.0.0.1" in "127.0.0.10").
+    """
+    if value is None:
+        return []
+    if isinstance(value, str):
+        return [h.strip() for h in value.split(",") if h.strip()]
+    if isinstance(value, (list, tuple)):
+        return [str(h).strip() for h in value if str(h).strip()]
+    return []

nvcurve/daemon.py

@@ -7,10 +7,16 @@ Protocol: newline-delimited JSON, one request → one response, connection close
 
 Commands:
   {"cmd": "ping"}
-  {"cmd": "serve_start", "host": "127.0.0.1", "port": 8042}
+  {"cmd": "serve_start"}
   {"cmd": "serve_stop"}
   {"cmd": "serve_status"}
 
+The socket is world-connectable (unprivileged users drive it via the CLI),
+so the command surface is deliberately minimal: serve_start ALWAYS binds the
+configured host/port from /etc/nvcurve/config.json — callers cannot choose
+the bind address (no ad-hoc 0.0.0.0 exposure). Changing the bind address is
+an operator action via `nvcurve service configure`.
+
 Requires root.
 """
 
@@ -23,7 +29,7 @@ import signal
 import subprocess
 import sys
 
-from .config import Config
+from .config import Config, normalize_trusted_proxies
 
 log = logging.getLogger("nvcurve.daemon")
 
@@ -38,7 +44,13 @@ _cfg: Config | None = None  # Config instance, set in run()
 # ── Socket command handlers ────────────────────────────────────────────────────
 
 
-async def _handle_serve_start(host: str, port: int) -> dict:
+async def _handle_serve_start() -> dict:
+    """Start the web server on the *configured* host/port.
+
+    The bind address is taken from /etc/nvcurve/config.json only — the
+    socket is reachable by unprivileged users, so callers must not be able
+    to choose the interface (e.g. binding 0.0.0.0 to expose the API).
+    """
     global _server_proc
     if _server_proc is not None and _server_proc.poll() is None:
         return {
@@ -47,6 +59,8 @@ async def _handle_serve_start(host: str, port: int) -> dict:
             "pid": _server_proc.pid,
         }
 
+    host = _cfg.host if _cfg is not None else "127.0.0.1"
+    port = _cfg.port if _cfg is not None else 8042
     cmd = [
         sys.executable,
         "-m",
@@ -72,7 +86,13 @@ async def _handle_serve_start(host: str, port: int) -> dict:
     except OSError as exc:
         return {"ok": False, "error": f"cannot open log file {log_path}: {exc}"}
     log.info("Web server started (PID %d)", _server_proc.pid)
-    return {"ok": True, "pid": _server_proc.pid}
+    return {
+        "ok": True,
+        "pid": _server_proc.pid,
+        "host": host,
+        "port": port,
+        "tls": bool(_cfg and _cfg.ssl_certfile and _cfg.ssl_keyfile),
+    }
 
 
 async def _handle_serve_stop() -> dict:
@@ -105,9 +125,7 @@ async def _dispatch(req: dict) -> dict:
     elif cmd == "serve_start":
         if _cfg is None:
             return {"ok": False, "error": "config not initialized"}
-        host = req.get("host", _cfg.host)
-        port = req.get("port", _cfg.port)
-        return await _handle_serve_start(host, port)
+        return await _handle_serve_start()
     elif cmd == "serve_stop":
         return await _handle_serve_stop()
     elif cmd == "serve_status":
@@ -174,9 +192,13 @@ def run() -> None:
         "profile_dir",
         "host",
         "port",
+        "ssl_certfile",
+        "ssl_keyfile",
     ):
         if key in cfg_data:
             setattr(_cfg, key, cfg_data[key])
+    if "trusted_proxies" in cfg_data:
+        _cfg.trusted_proxies = normalize_trusted_proxies(cfg_data["trusted_proxies"])
 
     # Apply auto-load profiles in a subprocess so the daemon process itself
     # never loads NvAPI/NVML/HAL modules — keeps steady-state RSS low.
@@ -207,7 +229,8 @@ async def _serve_socket(auto_serve: bool = False) -> None:
     server = await asyncio.start_unix_server(_handle_client, path=SOCKET_PATH)
     # The socket must be connectable by unprivileged users: the CLI runs as the
     # regular user and talks to this root daemon over the socket. 0o666 is
-    # intentional (standard for /run daemon sockets).
+    # intentional — the command surface is restricted accordingly (serve_start
+    # always uses the configured host/port; see module docstring).
     # pi-lens-ignore: S103
     _SOCKET_MODE = 0o666
     os.chmod(
@@ -220,7 +243,7 @@ async def _serve_socket(auto_serve: bool = False) -> None:
             log.warning("auto_serve requested but config not initialized")
         else:
             log.info("auto_serve enabled — starting web server on boot")
-            await _handle_serve_start(_cfg.host, _cfg.port)
+            await _handle_serve_start()
 
     stop_event = asyncio.Event()
     loop = asyncio.get_running_loop()

nvcurve/hal/fans.py

@@ -1,10 +1,15 @@
 """Hardware Abstraction Layer for Fan Control.
 
 Uses NVML (via pynvml) for all operations:
-  - nvmlDeviceGetFanSpeed_v2   : read current fan speed % for a fan index
-  - nvmlDeviceSetFanSpeed_v2   : set fan speed % for a fan index
-  - nvmlDeviceGetMinMaxFanSpeed: get min/max fan speed constraints
-  - nvmlDeviceGetTemperature   : read GPU temp for curve interpolation
+  - nvmlDeviceGetNumFans             : number of fans on the device
+  - nvmlDeviceGetFanSpeed_v2         : read current fan speed % for a fan index
+  - nvmlDeviceSetFanSpeed_v2         : set fan speed % for a fan index
+  - nvmlDeviceSetDefaultFanSpeed_v2  : restore automatic control for a fan index
+  - nvmlDeviceGetMinMaxFanSpeed      : get min/max fan speed constraints
+  - nvmlDeviceGetTemperature         : read GPU temp for curve interpolation
+
+Fans are addressed by 0-based index. Passing ``fans=None`` to the set/reset
+helpers means "all fans on the device".
 """
 
 import ctypes
@@ -24,9 +29,6 @@ pynvml: Any = _pynvml_import
 
 log = logging.getLogger("nvcurve.hal.fans")
 
-# We use fan index 0 (first/primary fan) for all operations.
-_FAN_INDEX = 0
-
 
 def _get_handle(gpu_index: int):
     """Return an NVML device handle."""
@@ -35,13 +37,42 @@ def _get_handle(gpu_index: int):
     return pynvml.nvmlDeviceGetHandleByIndex(gpu_index)
 
 
+def _num_fans(handle) -> int:
+    """Return the number of fans on the device (>= 1 on query failure)."""
+    try:
+        return max(0, int(pynvml.nvmlDeviceGetNumFans(handle)))
+    except pynvml.NVMLError:
+        # GetNumFans unsupported: assume at least the primary fan exists.
+        return 1
+
+
+def get_num_fans(gpu_index: int = 0) -> int:
+    """Return the number of fans on the GPU (0 if NVML is unavailable)."""
+    if not _NVML_AVAILABLE:
+        return 0
+    try:
+        return _num_fans(_get_handle(gpu_index))
+    except pynvml.NVMLError as exc:
+        log.warning("get_num_fans: %s", exc)
+        return 0
+
+
 def get_fan_info(gpu_index: int = 0) -> dict:
-    """Return current fan state: fan_pct, fan_mode, min_fan_pct, max_fan_pct.
+    """Return current fan state for all fans.
+
+    Returns a dict with:
+      fan_pct     : current speed % of fan 0 (legacy, None on failure)
+      fans        : [{"index": i, "fan_pct": pct | None}, ...] per fan
+      num_fans    : number of fans on the device
+      fan_mode    : None (the server derives "auto"/"curve")
+      min_fan_pct / max_fan_pct : device-wide speed constraints
 
     Returns None values on failure.
     """
-    out: dict[str, float | None] = {
+    out: dict[str, Any] = {
         "fan_pct": None,
+        "fans": [],
+        "num_fans": 0,
         "fan_mode": None,
         "min_fan_pct": None,
         "max_fan_pct": None,
@@ -50,36 +81,54 @@ def get_fan_info(gpu_index: int = 0) -> dict:
         return out
     try:
         handle = _get_handle(gpu_index)
-
-        # Get current fan speed using v2 API (fan index 0)
-        try:
-            out["fan_pct"] = float(pynvml.nvmlDeviceGetFanSpeed_v2(handle, _FAN_INDEX))
-        except pynvml.NVMLError:
-            # Fallback to legacy v1 API
-            try:
-                out["fan_pct"] = float(pynvml.nvmlDeviceGetFanSpeed(handle))
-            except pynvml.NVMLError:
-                pass
-
-        # Get min/max fan speed constraints
-        try:
-            min_s = ctypes.c_uint(0)
-            max_s = ctypes.c_uint(0)
-            pynvml.nvmlDeviceGetMinMaxFanSpeed(handle, min_s, max_s)
-            out["min_fan_pct"] = int(min_s.value)
-            out["max_fan_pct"] = int(max_s.value)
-        except pynvml.NVMLError:
-            out["min_fan_pct"] = 0
-            out["max_fan_pct"] = 100
-
     except pynvml.NVMLError as exc:
         log.warning("get_fan_info: %s", exc)
+        return out
+
+    out["num_fans"] = _num_fans(handle)
+
+    # Per-fan speeds via the v2 API; fan 0 falls back to the legacy v1 API.
+    for i in range(out["num_fans"]):
+        pct: float | None = None
+        try:
+            pct = float(pynvml.nvmlDeviceGetFanSpeed_v2(handle, i))
+        except pynvml.NVMLError:
+            if i == 0:
+                try:
+                    pct = float(pynvml.nvmlDeviceGetFanSpeed(handle))
+                except pynvml.NVMLError:
+                    pct = None
+        out["fans"].append({"index": i, "fan_pct": pct})
+
+    out["fan_pct"] = out["fans"][0]["fan_pct"] if out["fans"] else None
+
+    # Get min/max fan speed constraints
+    try:
+        min_s = ctypes.c_uint(0)
+        max_s = ctypes.c_uint(0)
+        pynvml.nvmlDeviceGetMinMaxFanSpeed(handle, min_s, max_s)
+        out["min_fan_pct"] = int(min_s.value)
+        out["max_fan_pct"] = int(max_s.value)
+    except pynvml.NVMLError:
+        out["min_fan_pct"] = 0
+        out["max_fan_pct"] = 100
 
     return out
 
 
-def set_fan_speed(gpu_index: int, pct: int) -> tuple[bool, str]:
-    """Set fan speed to a percentage (0-100) on the primary fan."""
+def set_fan_speed(
+    gpu_index: int,
+    pct: int,
+    fans: list[int] | None = None,
+) -> tuple[bool, str]:
+    """Set fan speed to a percentage (0-100).
+
+    fans=None targets every fan on the device; fans=[0, 1] targets the
+    listed fan indices. In all-fans mode, fans the driver does not allow
+    manual control of (e.g. driver-mirrored secondary fans) are skipped
+    with a warning instead of failing the whole operation; explicit fan
+    lists are strict and fail if any selected fan cannot be set.
+    """
     try:
         pct = max(0, min(100, int(pct)))
     except (TypeError, ValueError):
@@ -88,7 +137,47 @@ def set_fan_speed(gpu_index: int, pct: int) -> tuple[bool, str]:
         return False, "NVML not available"
     try:
         handle = _get_handle(gpu_index)
-        pynvml.nvmlDeviceSetFanSpeed_v2(handle, _FAN_INDEX, pct)
+        num_fans = _num_fans(handle)
+
+        if fans is None:
+            targets = list(range(num_fans))
+            strict = False
+        else:
+            targets: list[int] = []
+            for f in fans:
+                try:
+                    f = int(f)
+                except (TypeError, ValueError):
+                    return False, f"Invalid fan index: {f!r}"
+                if f < 0 or f >= num_fans:
+                    return False, f"Fan index {f} out of range (0-{num_fans - 1})"
+                targets.append(f)
+            strict = True
+            if not targets:
+                return False, "No fans selected"
+
+        if not targets:
+            return False, "No fans available on this GPU"
+
+        skipped: list[str] = []
+        for i in targets:
+            try:
+                pynvml.nvmlDeviceSetFanSpeed_v2(handle, i, pct)
+            except pynvml.NVMLError as exc:
+                if strict:
+                    log.warning(
+                        "set_fan_speed(%d, fan %d, %d): %s", gpu_index, i, pct, exc
+                    )
+                    return False, str(exc)
+                # All-fans mode: secondary fans may be driver-controlled and
+                # reject manual writes; skip them and report in the message.
+                log.debug("set_fan_speed: fan %d not settable: %s", i, exc)
+                skipped.append(f"fan {i + 1}")
+        if skipped:
+            return (
+                True,
+                f"OK ({len(skipped)} fan(s) not manually controllable: {', '.join(skipped)})",
+            )
         return True, "OK"
     except pynvml.NVMLError as exc:
         log.warning("set_fan_speed(%d, %d): %s", gpu_index, pct, exc)
@@ -96,10 +185,11 @@ def set_fan_speed(gpu_index: int, pct: int) -> tuple[bool, str]:
 
 
 def reset_fan(gpu_index: int = 0) -> tuple[bool, str]:
-    """Restore automatic fan control.
+    """Restore automatic fan control for all fans.
 
-    Tries nvidia-smi --fan=default first (most reliable), then falls back to
-    NVML nvmlDeviceSetDefaultFanSpeed_v2.
+    Tries nvidia-smi --fan=default first (most reliable, resets all fans on
+    the device), then falls back to NVML nvmlDeviceSetDefaultFanSpeed_v2
+    per fan index.
     """
     if not _NVML_AVAILABLE:
         return False, "NVML not available"
@@ -124,10 +214,14 @@ def reset_fan(gpu_index: int = 0) -> tuple[bool, str]:
     except Exception as exc:
         log.debug("nvidia-smi -fan default error: %s", exc)
 
-    # Fallback: use NVML to reset to default fan speed
+    # Fallback: use NVML to reset every fan to default speed
     try:
         handle = _get_handle(gpu_index)
-        pynvml.nvmlDeviceSetDefaultFanSpeed_v2(handle, _FAN_INDEX)
+        for i in range(_num_fans(handle)):
+            try:
+                pynvml.nvmlDeviceSetDefaultFanSpeed_v2(handle, i)
+            except pynvml.NVMLError as exc:
+                log.debug("reset_fan: fan %d: %s", i, exc)
         return True, "OK"
     except pynvml.NVMLError as exc:
         return False, f"Failed to reset fan: {exc}"

nvcurve/hal/limits.py

@@ -59,20 +59,37 @@ def _get_handle(gpu_index: int):
 # ── Power limit ───────────────────────────────────────────────────────────────
 
 
-def get_power_limit(gpu_index: int = 0) -> dict:
-    """Return dict with power_limit_w, default_power_limit_w, min_power_limit_w, max_power_limit_w."""
-    out: dict[str, int | None] = {
+def get_power_limit(gpu_index: int = 0, mode: str = "nvml") -> dict:
+    """Return dict with power limit info.
+
+    Keys: power_limit_w, default_power_limit_w, min_power_limit_w,
+    min_power_limit_w_native, max_power_limit_w, rm_power_supported,
+    power_cap_mode.
+
+    mode: "nvml" (default) or "ioctl" (experimental RM power control).
+    min_power_limit_w is the effective minimum: in ioctl mode it is
+    extended to the experimental floor (30 W) when the RM interface is
+    present and validated; min_power_limit_w_native is always the VBIOS
+    minimum. The RM probe is GET-only (no writes) and safe to run on
+    every call.
+    """
+    out: dict[str, int | bool | str | None] = {
         "power_limit_w": None,
         "default_power_limit_w": None,
         "min_power_limit_w": None,
+        "min_power_limit_w_native": None,
         "max_power_limit_w": None,
+        "rm_power_supported": False,
+        "power_cap_mode": mode,
     }
     try:
         handle = _get_handle(gpu_index)
         limit = pynvml.nvmlDeviceGetPowerManagementLimit(handle)
         constrs = pynvml.nvmlDeviceGetPowerManagementLimitConstraints(handle)
         out["power_limit_w"] = limit // 1000
-        out["min_power_limit_w"] = constrs[0] // 1000
+        native_min = constrs[0] // 1000
+        out["min_power_limit_w"] = native_min
+        out["min_power_limit_w_native"] = native_min
         out["max_power_limit_w"] = constrs[1] // 1000
         try:
             default = pynvml.nvmlDeviceGetPowerManagementDefaultLimit(handle)
@@ -81,11 +98,39 @@ def get_power_limit(gpu_index: int = 0) -> dict:
             log.debug("nvmlDeviceGetPowerManagementDefaultLimit: %s", exc)
     except Exception as exc:
         log.warning("get_power_limit: %s", exc)
+        return out
+
+    # GET-only RM discovery — reported so the UI can offer the experimental
+    # mode; the effective minimum only changes in ioctl mode.
+    try:
+        from . import rm_power
+
+        bounds = rm_power.probe_gpu(gpu_index)
+        out["rm_power_supported"] = bounds is not None
+        if bounds is not None and mode == "ioctl":
+            out["min_power_limit_w"] = bounds.lower_min_mw() // 1000
+    except Exception as exc:
+        log.debug("RM power probe failed: %s", exc)
     return out
 
 
-def set_power_limit(limit_w: int, gpu_index: int = 0) -> tuple[bool, str]:
-    """Set the board power limit (Watts)."""
+def set_power_limit(
+    limit_w: int, gpu_index: int = 0, mode: str = "nvml"
+) -> tuple[bool, str]:
+    """Set the board power limit (Watts).
+
+    mode "ioctl" (experimental) applies the limit through the undocumented
+    RM interface, which permits values below the VBIOS minimum. It has no
+    fallback: failures are reported, never silently switched to NVML.
+    """
+    if mode == "ioctl":
+        from . import rm_power
+
+        try:
+            rm_power.set_power_limit_w(gpu_index, limit_w)
+            return True, "OK"
+        except rm_power.RmPowerError as exc:
+            return False, str(exc)
     try:
         handle = _get_handle(gpu_index)
         pynvml.nvmlDeviceSetPowerManagementLimit(handle, limit_w * 1000)

nvcurve/hal/monitoring.py

@@ -162,6 +162,20 @@ def _nvml_read(gpu_index: int) -> dict:
         with contextlib.suppress(_pynvml.NVMLError):
             out["fan_pct"] = float(_pynvml.nvmlDeviceGetFanSpeed(handle))
 
+        # Per-fan speeds via the v2 API (fan_pct above stays fan 0 for legacy clients).
+        try:
+            num_fans = int(_pynvml.nvmlDeviceGetNumFans(handle))
+            fan_list: list[float | None] = []
+            for i in range(num_fans):
+                try:
+                    fan_list.append(float(_pynvml.nvmlDeviceGetFanSpeed_v2(handle, i)))
+                except _pynvml.NVMLError:
+                    fan_list.append(None)
+            if fan_list:
+                out["fans"] = fan_list
+        except _pynvml.NVMLError:
+            pass
+
         with contextlib.suppress(_pynvml.NVMLError):
             out["throttle_reasons"] = int(
                 _pynvml.nvmlDeviceGetCurrentClocksThrottleReasons(handle)

nvcurve/hal/rm_power.py

@@ -0,0 +1,627 @@
+"""Undocumented NVIDIA RM power-limit interface (EXPERIMENTAL).
+
+Port of the approach from LACT PR #1205 (ilya-zlobintsev/LACT): applies board
+power limits through the private NV2080 power-limit "ordinary client"
+interface on /dev/nvidiactl, which permits caps below the VBIOS minimum
+(down to 30 W). The native maximum still applies.
+
+EXPERIMENTAL — uses an undocumented driver interface. It may break after
+driver updates. Discovery is GET-only and validates the RM payload against
+NVML before any write is issued; a failed write restores the previous
+request (even if it was below the VBIOS minimum).
+"""
+
+from __future__ import annotations
+
+import contextlib
+import ctypes
+import fcntl
+import logging
+import os
+import struct
+import sys
+from collections.abc import Callable
+from dataclasses import dataclass
+
+log = logging.getLogger("nvcurve.hal.rm_power")
+
+# ── ioctl constants (nv-ioctl.h / nv-ioctl-numbers.h) ─────────────────────────
+
+NV_IOCTL_MAGIC = ord("N")  # 0x4E — user-space RM interface
+NV_ESC_RM_ALLOC = 0x2B
+NV_ESC_RM_CONTROL = 0x2A
+
+# 'F' magic interface (kernel-open/common/inc/nv-ioctl-numbers.h) —
+# NV_ESC_REGISTER_FD lives here, not in the 'N' RM interface.
+NV_IOCTL_MAGIC_F = ord("F")  # 0x46
+NV_IOCTL_BASE_F = 200
+NV_ESC_REGISTER_FD = NV_IOCTL_BASE_F + 1  # 201
+
+# RM class IDs (nv0080.h / nv2080.h)
+NV01_DEVICE_0 = 0x0080
+NV20_SUBDEVICE_0 = 0x2080
+
+# NV01_ROOT GPU queries (ctrl0000gpu.h) — resolve PCI identity to the RM
+# device/subdevice instance numbers used by NV0080 and NV2080 allocations;
+# neither number is a Linux device minor.
+_CTRL_GPU_GET_ATTACHED_IDS = 0x201
+_CTRL_GPU_GET_ID_INFO_V2 = 0x205
+_CTRL_GPU_GET_PCI_INFO = 0x21B
+_MAX_GPUS = 32
+_INVALID_GPU_ID = 0xFFFFFFFF
+
+# Private NV2080 power-limit client commands. Payloads compared against
+# NvAPI and GSP from R595, R610 and R615 (native RM payloads, without
+# NvAPI's 0x10-byte transport prefix).
+_PWR_GET_INFO = 0x2080_A630
+_PWR_GET_CONTROL = 0x2080_A632
+_PWR_SET_CONTROL = 0x2080_E633
+_ORDINARY_CLIENT = 0xFE
+_LOWER_LIMIT_MW = 30_000  # experimental floor: 30 W
+
+
+def _ioctl_rw(size: int, nr: int, magic: int = NV_IOCTL_MAGIC) -> int:
+    """Linux ioctl request code: dir=RW, given size/type/nr."""
+    return (2 << 30) | (size << 16) | (magic << 8) | nr
+
+
+def _ioctl_call(fd: int, code: int, arg) -> None:
+    """Issue an ioctl, converting errno failures to RmPowerError.
+
+    The driver normally reports failures as an RM status in the parameter
+    struct, but an experimental interface can also fail at the kernel level
+    (ENOTTY/EBADF/EPERM across driver versions). Converting to RmPowerError
+    keeps the module's error contract uniform and lets callers clean up fds.
+    """
+    try:
+        fcntl.ioctl(fd, code, arg)
+    except OSError as exc:
+        raise RmPowerError(f"ioctl 0x{code:x} failed: {exc}") from exc
+
+
+# ── NVOS parameter structs (nvos.h) ──────────────────────────────────────────
+
+
+class _NVOS21(ctypes.Structure):
+    _fields_ = [
+        ("hRoot", ctypes.c_uint32),
+        ("hObjectParent", ctypes.c_uint32),
+        ("hObjectNew", ctypes.c_uint32),
+        ("hClass", ctypes.c_uint32),
+        ("pAllocParms", ctypes.c_uint64),
+        ("paramsSize", ctypes.c_uint32),
+        ("status", ctypes.c_uint32),
+    ]
+
+
+class _NVOS64(ctypes.Structure):
+    _fields_ = [
+        ("hRoot", ctypes.c_uint32),
+        ("hObjectParent", ctypes.c_uint32),
+        ("hObjectNew", ctypes.c_uint32),
+        ("hClass", ctypes.c_uint32),
+        ("pAllocParms", ctypes.c_uint64),
+        ("pRightsRequested", ctypes.c_uint64),
+        ("paramsSize", ctypes.c_uint32),
+        ("flags", ctypes.c_uint32),
+        ("status", ctypes.c_uint32),
+    ]
+
+
+class _NVOS54(ctypes.Structure):
+    _fields_ = [
+        ("hClient", ctypes.c_uint32),
+        ("hObject", ctypes.c_uint32),
+        ("cmd", ctypes.c_uint32),
+        ("flags", ctypes.c_uint32),
+        ("params", ctypes.c_uint64),
+        ("paramsSize", ctypes.c_uint32),
+        ("status", ctypes.c_uint32),
+    ]
+
+
+class _NV0080_ALLOC(ctypes.Structure):
+    _fields_ = [
+        ("deviceId", ctypes.c_uint32),
+        ("deviceFlags", ctypes.c_uint32),
+        ("vgpuInstance", ctypes.c_uint32),
+        ("pad", ctypes.c_uint32),
+    ]
+
+
+class _NV2080_ALLOC(ctypes.Structure):
+    _fields_ = [
+        ("subDeviceId", ctypes.c_uint32),
+        ("clientShare", ctypes.c_uint32),
+        ("flags", ctypes.c_uint32),
+        ("pad", ctypes.c_uint32),
+    ]
+
+
+# ── Errors ───────────────────────────────────────────────────────────────────
+
+
+class RmPowerError(RuntimeError):
+    """Raised when the RM power-limit interface is unavailable or fails."""
+
+
+# ── Power-limit layouts and bounds ───────────────────────────────────────────
+
+
+@dataclass(frozen=True)
+class PowerLimitLayout:
+    """Byte offsets of the private power-limit payloads for one wire format."""
+
+    name: str
+    info_size: int
+    control_size: int
+    info_min_at: int
+    request_at: int
+    client_at: int
+    mask_end: int
+
+
+EXTENDED_LAYOUT = PowerLimitLayout(
+    name="extended",
+    info_size=0x924,
+    control_size=0x328,
+    info_min_at=0x28,
+    request_at=0x2C,
+    client_at=0x30,
+    mask_end=0x24,
+)
+LEGACY_LAYOUT = PowerLimitLayout(
+    name="legacy",
+    info_size=0x488,
+    control_size=0x188,
+    info_min_at=0xC,
+    request_at=0xC,
+    client_at=0x10,
+    mask_end=0x8,
+)
+
+
+@dataclass(frozen=True)
+class PowerLimitBounds:
+    """Power limit bounds in milliwatts (NVML/RM units)."""
+
+    min_mw: int
+    default_mw: int
+    max_mw: int
+
+    def lower_min_mw(self) -> int:
+        """Effective minimum when the experimental route is active."""
+        return min(self.min_mw, _LOWER_LIMIT_MW)
+
+
+@dataclass(frozen=True)
+class LowerPowerLimit:
+    """A validated RM power-limit layout that can be written."""
+
+    bounds: PowerLimitBounds
+    layout: PowerLimitLayout
+
+    def lower_min_mw(self) -> int:
+        return self.bounds.lower_min_mw()
+
+
+# ── PCI identity → RM instance resolution ────────────────────────────────────
+
+
+@dataclass(frozen=True)
+class PciLocation:
+    domain: int
+    bus: int
+    dev: int
+    func: int = 0
+
+
+def resolve_gpu_instance(
+    pci: PciLocation,
+    query: Callable[[int, bytearray], None],
+) -> tuple[int, int]:
+    """Resolve (device_instance, subdevice_instance) by PCI identity.
+
+    /dev/nvidiaN minors and RM device instances can have different orders;
+    the RM object must be matched by PCI domain/bus/slot, not by index.
+    The RM query exposes domain/bus/slot but no PCI function, so only
+    function-zero devices can be matched (never another function of a
+    multifunction device).
+    """
+    if pci.func != 0:
+        raise RmPowerError("RM GPU lookup requires PCI function zero")
+
+    attached = bytearray(_MAX_GPUS * 4)
+    query(_CTRL_GPU_GET_ATTACHED_IDS, attached)
+
+    for i in range(_MAX_GPUS):
+        gpu_id = struct.unpack_from("<I", attached, i * 4)[0]
+        if gpu_id == _INVALID_GPU_ID:
+            continue
+
+        # NV0000_CTRL_GPU_GET_PCI_INFO_PARAMS: u32 gpuId, u32 domain,
+        # u16 bus, u16 slot.
+        location = bytearray(12)
+        location[0:4] = struct.pack("<I", gpu_id)
+        query(_CTRL_GPU_GET_PCI_INFO, location)
+        domain, bus, slot = struct.unpack_from("<IHH", location, 4)
+        if (domain, bus, slot) != (pci.domain, pci.bus, pci.dev):
+            continue
+
+        # NV0000_CTRL_GPU_GET_ID_INFO_V2_PARAMS: eight u32 fields, with
+        # deviceInstance/subDeviceInstance at +8/+12.
+        info = bytearray(32)
+        info[0:4] = struct.pack("<I", gpu_id)
+        query(_CTRL_GPU_GET_ID_INFO_V2, info)
+        device, subdevice = struct.unpack_from("<II", info, 8)
+        return device, subdevice
+
+    raise RmPowerError(f"no RM GPU matches PCI location {pci}")
+
+
+# ── RM handle ────────────────────────────────────────────────────────────────
+
+
+def _rm_control(fd: int, client: int, obj: int, cmd: int, buf: bytearray) -> None:
+    """Issue an NVOS54 RM control whose parameter block is a byte buffer."""
+    arr = (ctypes.c_uint8 * len(buf)).from_buffer(buf)
+    req = _NVOS54(
+        hClient=client,
+        hObject=obj,
+        cmd=cmd,
+        flags=0,
+        params=ctypes.addressof(arr),
+        paramsSize=len(buf),
+        status=0,
+    )
+    _ioctl_call(fd, _ioctl_rw(ctypes.sizeof(_NVOS54), NV_ESC_RM_CONTROL), req)
+    if req.status != 0:
+        raise RmPowerError(
+            f"RM control 0x{cmd:08x} failed with status 0x{req.status:x}"
+        )
+
+
+def _alloc_client(fd: int) -> int:
+    """Allocate an RM client (NVOS21, all-zero parameters)."""
+    req = _NVOS21()
+    _ioctl_call(fd, _ioctl_rw(ctypes.sizeof(_NVOS21), NV_ESC_RM_ALLOC), req)
+    if req.status != 0:
+        raise RmPowerError(f"could not allocate RM client (status 0x{req.status:x})")
+    return req.hObjectNew
+
+
+def _alloc_object(
+    fd: int, client: int, parent: int, class_id: int, alloc_params: ctypes.Structure
+) -> int:
+    """Allocate an RM object (NVOS64) and return its handle."""
+    req = _NVOS64(
+        hRoot=client,
+        hObjectParent=parent,
+        hObjectNew=0,
+        hClass=class_id,
+        pAllocParms=ctypes.addressof(alloc_params),
+        pRightsRequested=0,
+        paramsSize=ctypes.sizeof(alloc_params),
+        flags=0,
+        status=0,
+    )
+    _ioctl_call(fd, _ioctl_rw(ctypes.sizeof(_NVOS64), NV_ESC_RM_ALLOC), req)
+    if req.status != 0:
+        raise RmPowerError(
+            f"RM class 0x{class_id:x} allocation failed (status 0x{req.status:x})"
+        )
+    return req.hObjectNew
+
+
+def _register_fd(device_fd: int, nvidiactl_fd: int) -> None:
+    """Register the nvidiactl client with the device fd (NV_ESC_REGISTER_FD).
+
+    The ioctl is issued on the /dev/nvidiaN fd; the argument is the
+    nvidiactl fd to associate with it.
+    """
+    _ioctl_call(
+        device_fd,
+        _ioctl_rw(4, NV_ESC_REGISTER_FD, NV_IOCTL_MAGIC_F),
+        struct.pack("i", nvidiactl_fd),
+    )
+
+
+class RmHandle:
+    """An NVIDIA RM client with device + subdevice objects for one GPU."""
+
+    def __init__(
+        self,
+        nvidiactl_fd: int,
+        device_fd: int,
+        client_handle: int,
+        device_handle: int,
+        subdevice_handle: int,
+    ) -> None:
+        self._nvidiactl_fd = nvidiactl_fd
+        self._device_fd = device_fd
+        self.client_handle = client_handle
+        self.device_handle = device_handle
+        self.subdevice_handle = subdevice_handle
+
+    @classmethod
+    def open(cls, gpu_index: int) -> RmHandle:
+        """Open an RM handle for the GPU at the given NVML index.
+
+        The RM device/subdevice instances are resolved by PCI identity
+        (minors and RM instances can have different orders).
+        """
+        pynvml = _ensure_nvml()
+
+        try:
+            handle = pynvml.nvmlDeviceGetHandleByIndex(gpu_index)
+            minor = int(pynvml.nvmlDeviceGetMinorNumber(handle))
+            pci_info = pynvml.nvmlDeviceGetPciInfo(handle)
+            pci = PciLocation(
+                domain=int(pci_info.domain),
+                bus=int(pci_info.bus),
+                dev=int(pci_info.device),
+            )
+        except Exception as exc:
+            raise RmPowerError(f"NVML query for GPU {gpu_index} failed: {exc}") from exc
+
+        try:
+            nvidiactl_fd = os.open("/dev/nvidiactl", os.O_RDWR)
+        except OSError as exc:
+            raise RmPowerError(f"could not open /dev/nvidiactl: {exc}") from exc
+
+        try:
+            client_handle = _alloc_client(nvidiactl_fd)
+            device_instance, subdevice_instance = resolve_gpu_instance(
+                pci,
+                lambda cmd, buf: _rm_control(
+                    nvidiactl_fd, client_handle, client_handle, cmd, buf
+                ),
+            )
+        except RmPowerError:
+            os.close(nvidiactl_fd)
+            raise
+
+        try:
+            device_fd = os.open(f"/dev/nvidia{minor}", os.O_RDWR)
+        except OSError as exc:
+            os.close(nvidiactl_fd)
+            raise RmPowerError(f"could not open /dev/nvidia{minor}: {exc}") from exc
+
+        try:
+            _register_fd(device_fd, nvidiactl_fd)
+            device_handle = _alloc_object(
+                nvidiactl_fd,
+                client_handle,
+                client_handle,
+                NV01_DEVICE_0,
+                _NV0080_ALLOC(deviceId=device_instance),
+            )
+            subdevice_handle = _alloc_object(
+                nvidiactl_fd,
+                client_handle,
+                device_handle,
+                NV20_SUBDEVICE_0,
+                _NV2080_ALLOC(subDeviceId=subdevice_instance),
+            )
+        except RmPowerError:
+            os.close(device_fd)
+            os.close(nvidiactl_fd)
+            raise
+
+        return cls(
+            nvidiactl_fd, device_fd, client_handle, device_handle, subdevice_handle
+        )
+
+    def control(self, cmd: int, buf: bytearray) -> None:
+        """Issue an NVOS54 RM control on the subdevice with a byte buffer."""
+        _rm_control(
+            self._nvidiactl_fd, self.client_handle, self.subdevice_handle, cmd, buf
+        )
+
+    def close(self) -> None:
+        """Close the fds; the driver reclaims the RM client objects."""
+        with contextlib.suppress(OSError):
+            os.close(self._device_fd)
+        with contextlib.suppress(OSError):
+            os.close(self._nvidiactl_fd)
+
+
+# ── Power-limit probe / set (pure logic, testable with a fake query) ─────────
+
+
+def _u32(data: bytearray | bytes, offset: int) -> int:
+    return struct.unpack_from("<I", data, offset)[0]
+
+
+def _validate_header(layout: PowerLimitLayout, data: bytearray) -> None:
+    if _u32(data, 0) != 0xFF or _u32(data, 4) != 1:
+        raise RmPowerError("unrecognized RM power client layout")
+    # The extended layout has additional mask words; accepting only its low
+    # word would allow an unexpected client to be included in a later SET.
+    if any(byte != 0 for byte in data[8 : layout.mask_end]):
+        raise RmPowerError("unrecognized RM power client layout")
+
+
+def _read_bounds(
+    layout: PowerLimitLayout, query: Callable[[int, bytearray], None]
+) -> PowerLimitBounds:
+    info = bytearray(layout.info_size)
+    query(_PWR_GET_INFO, info)
+    _validate_header(layout, info)
+    bounds = PowerLimitBounds(
+        min_mw=_u32(info, layout.info_min_at),
+        default_mw=_u32(info, layout.info_min_at + 4),
+        max_mw=_u32(info, layout.info_min_at + 8),
+    )
+    if not (
+        bounds.min_mw > 0
+        and bounds.min_mw <= bounds.default_mw
+        and bounds.default_mw <= bounds.max_mw
+    ):
+        raise RmPowerError("invalid RM power limit bounds")
+    return bounds
+
+
+def _read_control(
+    layout: PowerLimitLayout, query: Callable[[int, bytearray], None]
+) -> bytearray:
+    control = bytearray(layout.control_size)
+    control[4:8] = struct.pack("<I", 1)
+    control[layout.client_at] = _ORDINARY_CLIENT
+    query(_PWR_GET_CONTROL, control)
+    _validate_header(layout, control)
+    if control[layout.client_at] != _ORDINARY_CLIENT:
+        raise RmPowerError("unexpected power client")
+    if _u32(control, layout.request_at) in (0, 0xFFFFFFFF):
+        raise RmPowerError("no ordinary power request available")
+    return control
+
+
+def probe(
+    nvml_bounds: PowerLimitBounds,
+    nvml_current_mw: int,
+    query: Callable[[int, bytearray], None],
+) -> LowerPowerLimit:
+    """GET-only discovery of the RM power-limit layout.
+
+    Probes the two known wire formats using GETs only. A driver version
+    number is not evidence that the payload still has the same layout or
+    units, so the bounds and the current request are validated against
+    NVML. Discovery never issues a SET.
+    """
+    if sys.byteorder != "little":
+        raise RmPowerError("little-endian host required")
+    errors: list[str] = []
+    for layout in (EXTENDED_LAYOUT, LEGACY_LAYOUT):
+        try:
+            bounds = _read_bounds(layout, query)
+            if bounds != nvml_bounds:
+                raise RmPowerError("RM power bounds differ from NVML")
+            control = _read_control(layout, query)
+            if _u32(control, layout.request_at) != nvml_current_mw:
+                raise RmPowerError("RM ordinary power request differs from NVML")
+            return LowerPowerLimit(bounds=bounds, layout=layout)
+        except RmPowerError as exc:
+            errors.append(f"{layout.name}: {exc}")
+    raise RmPowerError("no compatible RM power layout: " + "; ".join(errors))
+
+
+def set_limit(
+    limit_mw: int,
+    support: LowerPowerLimit,
+    query: Callable[[int, bytearray], None],
+) -> None:
+    """Set the ordinary-client power request with readback verification.
+
+    Keeps the entire current payload, changing only entry 0's request.
+    Mask 1 and selector 0xFE prevent modifying any other entry or the
+    additional F8 client. A failed SET can have side effects, so the
+    previous request is restored even on transport failure — and the
+    restore uses 0xFE so a previous limit below the VBIOS minimum can
+    also be restored.
+    """
+    layout = support.layout
+    bounds = _read_bounds(layout, query)
+    if bounds != support.bounds:
+        raise RmPowerError("RM power bounds changed since discovery")
+    lower = bounds.lower_min_mw()
+    if not (lower <= limit_mw <= bounds.max_mw):
+        raise RmPowerError(
+            f"power limit {limit_mw} mW outside supported range "
+            f"{lower}..{bounds.max_mw} mW"
+        )
+
+    before = _read_control(layout, query)
+    if _u32(before, layout.request_at) == limit_mw:
+        return
+
+    expected = bytearray(before)
+    expected[layout.request_at : layout.request_at + 4] = struct.pack("<I", limit_mw)
+
+    try:
+        request = bytearray(expected)
+        query(_PWR_SET_CONTROL, request)
+        if _read_control(layout, query) != expected:
+            raise RmPowerError("power request readback differs")
+    except RmPowerError as apply_error:
+        try:
+            restore = bytearray(before)
+            query(_PWR_SET_CONTROL, restore)
+            if _read_control(layout, query) != before:
+                raise RmPowerError("restored power request differs")
+        except RmPowerError as restore_error:
+            raise RmPowerError(
+                f"power request failed: {apply_error}; "
+                f"restoration also failed: {restore_error}"
+            ) from None
+        raise RmPowerError(f"{apply_error} (previous power request restored)") from None
+
+
+# ── High-level API (wires NVML state + RmHandle to the pure logic) ───────────
+
+
+def _ensure_nvml():
+    """Return pynvml with NVML initialized (nvmlInit is refcounted)."""
+    import pynvml
+
+    pynvml.nvmlInit()
+    return pynvml
+
+
+def _nvml_power_state(gpu_index: int) -> tuple[PowerLimitBounds, int]:
+    """Return (bounds, current_mw) from NVML for the given GPU."""
+    pynvml = _ensure_nvml()
+
+    try:
+        handle = pynvml.nvmlDeviceGetHandleByIndex(gpu_index)
+        min_mw, max_mw = pynvml.nvmlDeviceGetPowerManagementLimitConstraints(handle)
+        default_mw = pynvml.nvmlDeviceGetPowerManagementDefaultLimit(handle)
+        current_mw = pynvml.nvmlDeviceGetPowerManagementLimit(handle)
+        bounds = PowerLimitBounds(int(min_mw), int(default_mw), int(max_mw))
+        current = int(current_mw)
+    except Exception as exc:
+        raise RmPowerError(
+            f"NVML power state for GPU {gpu_index} unavailable: {exc}"
+        ) from exc
+    return bounds, current
+
+
+def probe_gpu(gpu_index: int = 0) -> PowerLimitBounds | None:
+    """GET-only discovery of the RM power-limit interface for a GPU.
+
+    Returns the validated power bounds (milliwatts) when a compatible RM
+    layout is present, else None. Never issues a write.
+    """
+    try:
+        bounds, current = _nvml_power_state(gpu_index)
+    except Exception as exc:
+        log.debug("RM probe: NVML state unavailable: %s", exc)
+        return None
+    try:
+        handle = RmHandle.open(gpu_index)
+    except RmPowerError as exc:
+        log.debug("RM probe: handle open failed: %s", exc)
+        return None
+    try:
+        probe(bounds, current, handle.control)
+        return bounds
+    except RmPowerError as exc:
+        log.debug("RM probe: %s", exc)
+        return None
+    finally:
+        handle.close()
+
+
+def set_power_limit_w(gpu_index: int, limit_w: int) -> None:
+    """Set the board power limit (watts) via the RM interface.
+
+    Raises RmPowerError on any failure (probe, range, write, readback).
+    A failed write restores the previous request.
+    """
+    bounds, current = _nvml_power_state(gpu_index)
+    handle = RmHandle.open(gpu_index)
+    try:
+        support = probe(bounds, current, handle.control)
+        set_limit(int(limit_w) * 1000, support, handle.control)
+    finally:
+        handle.close()

nvcurve/hal/snapshot.py

@@ -121,6 +121,15 @@ def restore(gpu, snapshot_dir: str, filepath: str | None = None) -> bool:
         print(f"Snapshot file not found: {filepath}")
         return False
 
+    # Contain the path inside the snapshot directory — callers (in
+    # particular the HTTP API) must not be able to point the restore at
+    # arbitrary files on the filesystem.
+    snap_dir = os.path.realpath(snapshot_dir)
+    resolved = os.path.realpath(filepath)
+    if not resolved.startswith(snap_dir + os.sep):
+        print(f"Snapshot path outside snapshot directory: {filepath}")
+        return False
+
     try:
         with open(filepath, "rb") as f:
             raw = f.read()

nvcurve/nvapi/bootstrap.py

@@ -9,7 +9,7 @@ from .errors import NVAPI_ERRORS
 
 def load_nvapi() -> ctypes.CDLL:
     """Load libnvidia-api.so from the NVIDIA driver."""
-    for name in ("libnvidia-api.so", "libnvidia-api.so.1"):
+    for name in ("libnvidia-api.so", "libnvidia-api.so.1"):  # gitleaks:allow
         try:
             return ctypes.CDLL(name)
         except OSError:

nvcurve/nvapi/types.py

@@ -61,6 +61,7 @@ class MonitoringSample:
     pcie_link_width: int | None = None  # Current PCIe link width (x1..x16)
     pcie_link_generation: int | None = None  # Current PCIe link generation (1..5)
     mem_temp_c: float | None = None  # VRAM temperature (if the GPU exposes it)
+    fans: list[float | None] | None = None  # Per-fan speed % (index-aligned)
 
 
 @dataclass

nvcurve/profiles/apply.py

@@ -43,7 +43,8 @@ def apply_profile(gpu_index: int, name: str, cfg) -> list[str]:
             errs.append(f"Mem offset: {msg}")
 
     if profile.power_limit_w is not None:
-        ok, msg = set_power_limit(profile.power_limit_w, gpu_index)
+        mode = profile.power_cap_mode or "nvml"
+        ok, msg = set_power_limit(profile.power_limit_w, gpu_index, mode)
         if not ok:
             errs.append(f"Power limit: {msg}")
 

nvcurve/profiles/native.py

@@ -16,7 +16,12 @@ class ProfileData:
     curve_deltas: dict[str, int]  # { "index": delta_khz }
     mem_offset_mhz: int | None = None
     power_limit_w: int | None = None
+    # How power_limit_w is applied: "nvml" (default) or "ioctl" (experimental
+    # RM power control, permits values below the VBIOS minimum).
+    power_cap_mode: str | None = None
     fan_curve: list[dict[str, int]] | None = None
+    # Fan indices controlled by fan_curve (0-based); None = all fans.
+    fan_targets: list[int] | None = None
 
 
 def save_profile(profile_dir: str, data: ProfileData) -> str:
@@ -53,6 +58,9 @@ def load_profile(filepath: str) -> ProfileData:
     # Drop removed fields so old profiles don't cause TypeError.
     for obsolete in ("gpu_locked_min_mhz", "gpu_locked_max_mhz", "vram_p0_offset_mhz"):
         data.pop(obsolete, None)
+    # Normalize the experimental power-cap mode; unknown values fall back to NVML.
+    if data.get("power_cap_mode") not in (None, "nvml", "ioctl"):
+        data["power_cap_mode"] = None
     return ProfileData(**data)
 
 

nvcurve/server.py

@@ -11,7 +11,7 @@ import logging
 import os
 from contextlib import asynccontextmanager, suppress
 from pathlib import Path
-from typing import Any
+from typing import Any, Protocol
 
 from fastapi import FastAPI, HTTPException, Request, WebSocket, WebSocketDisconnect
 from fastapi.middleware.cors import CORSMiddleware
@@ -20,10 +20,11 @@ from fastapi.staticfiles import StaticFiles
 from pydantic import BaseModel
 
 from . import auth
-from .config import Config, default_config
+from .config import Config, default_config, tls_enabled
 from .hal.dashboard import get_dashboard_info
 from .hal.fans import (
     get_fan_info,
+    get_num_fans,
     get_temp,
     interpolate_fan_speed,
     reset_fan,
@@ -149,6 +150,7 @@ def _sample_dict(s) -> dict:
         "temp_c": s.temp_c,
         "power_w": s.power_w,
         "fan_pct": s.fan_pct,
+        "fans": s.fans,
         "pstate": s.pstate,
         "pstate_label": f"P{s.pstate}" if s.pstate is not None else None,
         "mem_used_bytes": s.mem_used_bytes,
@@ -219,7 +221,8 @@ async def _monitor_poller(gpu_index: int) -> None:
 
 
 async def _fan_poller(gpu_index: int) -> None:
-    """Continuously read GPU temp, interpolate fan speed from active curve, and apply."""
+    """Continuously read GPU temp, interpolate fan speed from active curve, and apply it to the target fans."""
+    last_write_error: str | None = None
     while True:
         try:
             g_state = _state["gpus"].get(gpu_index)
@@ -229,7 +232,25 @@ async def _fan_poller(gpu_index: int) -> None:
                     curve = g_state["fan_curve"]
                     target = interpolate_fan_speed(curve, temp)
                     if target is not None:
-                        await _run(set_fan_speed, gpu_index, target)
+                        ok, msg = await _run(
+                            set_fan_speed,
+                            gpu_index,
+                            target,
+                            g_state.get("fan_targets"),
+                        )
+                        if not ok:
+                            # Log once per distinct failure so a stuck target
+                            # list doesn't spam a warning every 2 s tick.
+                            if msg != last_write_error:
+                                log.warning(
+                                    "Fan write failed for GPU %d (targets=%s): %s",
+                                    gpu_index,
+                                    g_state.get("fan_targets"),
+                                    msg,
+                                )
+                            last_write_error = msg
+                        else:
+                            last_write_error = None
         except asyncio.CancelledError:
             return
         except Exception as exc:
@@ -237,15 +258,34 @@ async def _fan_poller(gpu_index: int) -> None:
         await asyncio.sleep(2.0)
 
 
-async def _activate_fan_curve(gpu_index: int, curve: list) -> None:
+async def _activate_fan_curve(
+    gpu_index: int, curve: list, fans: list[int] | None = None
+) -> None:
     """Set the active fan curve, (re)start the poller, and persist it.
 
-    Persistence (config.json) is what makes the curve survive server restarts:
-    fan control is volatile, so the driver reverts to automatic mode on reboot
-    and the saved curve is re-applied at the next server start.
+    fans=None targets all fans on the device; a list targets the given
+    fan indices. Persistence (config.json) is what makes the curve survive
+    server restarts: fan control is volatile, so the driver reverts to
+    automatic mode on reboot and the saved curve is re-applied at the next
+    server start.
     """
     g_state = _get_gpu_state(gpu_index)
 
+    # Validate explicit fan targets against the hardware. Stale indices
+    # (e.g. a profile saved on a 2-fan GPU applied to a 1-fan GPU, or a
+    # persisted entry restored after a hardware change) would otherwise
+    # make the poller fail silently on every tick.
+    if fans is not None:
+        num_fans = await _run(get_num_fans, gpu_index)
+        if not fans or (num_fans > 0 and any(f < 0 or f >= num_fans for f in fans)):
+            log.warning(
+                "Fan targets %s invalid for GPU %d (%d fan(s)); falling back to all fans",
+                fans,
+                gpu_index,
+                num_fans,
+            )
+            fans = None
+
     # Stop existing poller if running
     if g_state.get("fan_poller_task"):
         g_state["fan_poller_task"].cancel()
@@ -254,10 +294,11 @@ async def _activate_fan_curve(gpu_index: int, curve: list) -> None:
 
     g_state["fan_curve"] = curve
     g_state["fan_curve_active"] = True
+    g_state["fan_targets"] = fans
     g_state["fan_poller_task"] = asyncio.create_task(_fan_poller(gpu_index))
 
     cfg: Config = _state["config"]
-    cfg.fan_curves[_gpu_stable_key(gpu_index)] = curve
+    cfg.fan_curves[_gpu_stable_key(gpu_index)] = {"curve": curve, "fans": fans}
     _persist_fan_curves(cfg.fan_curves)
 
 
@@ -276,6 +317,7 @@ async def _deactivate_fan_curve(gpu_index: int, reset_hardware: bool = True) ->
 
     g_state["fan_curve"] = None
     g_state["fan_curve_active"] = False
+    g_state["fan_targets"] = None
 
     if reset_hardware:
         ok, msg = await _run(reset_fan, gpu_index)
@@ -389,7 +431,15 @@ async def lifespan(app: FastAPI):
         if g_state.get("fan_curve_active"):
             continue  # already activated by the auto-load profile path
         key = _gpu_stable_key(gpu_index)
-        curve = cfg.fan_curves.get(key)
+        entry = cfg.fan_curves.get(key)
+        if not entry:
+            continue
+        # Migrate the legacy format (bare curve list) to the current
+        # {"curve": ..., "fans": ...} shape; legacy entries targeted all fans.
+        if isinstance(entry, list):
+            entry = {"curve": entry, "fans": None}
+        curve = entry.get("curve") if isinstance(entry, dict) else None
+        fans = entry.get("fans") if isinstance(entry, dict) else None
         if not curve:
             continue
         ok, msg = validate_curve(curve)
@@ -398,7 +448,7 @@ async def lifespan(app: FastAPI):
             continue
         log.info("Restoring persisted fan curve on GPU %d (%s)", gpu_index, key)
         try:
-            await _activate_fan_curve(gpu_index, curve)
+            await _activate_fan_curve(gpu_index, curve, fans)
         except Exception as exc:
             log.warning(
                 "Failed to restore persisted fan curve on GPU %d: %s",
@@ -502,12 +552,10 @@ app.add_middleware(AuthMiddleware)
 
 class WriteRequest(BaseModel):
     deltas: dict[int, int]  # {point_index: delta_kHz}
-    max_delta_khz: int | None = None  # per-request safety limit override
 
 
 class GlobalOffsetRequest(BaseModel):
     delta_khz: int
-    max_delta_khz: int | None = None  # per-request safety limit override
 
 
 class VerifyRequest(BaseModel):
@@ -521,6 +569,8 @@ class SnapshotRestoreRequest(BaseModel):
 class LimitsRequest(BaseModel):
     power_limit_w: int | None = None
     mem_offset_mhz: int | None = None
+    # "nvml" (default) or "ioctl" (experimental RM power control).
+    power_cap_mode: str | None = None
 
 
 class ProfileSaveRequest(BaseModel):
@@ -543,10 +593,14 @@ class FanCurvePoint(BaseModel):
 
 class FanCurveRequest(BaseModel):
     curve: list[FanCurvePoint]
+    # Fan indices to control (0-based); None = all fans on the device.
+    fans: list[int] | None = None
 
 
 class FanSpeedRequest(BaseModel):
     fan_pct: int
+    # Specific fan index to set (0-based); None = all fans on the device.
+    fan: int | None = None
 
 
 class LoginRequest(BaseModel):
@@ -600,7 +654,7 @@ async def api_auth_login(req: LoginRequest, request: Request):
     if not users:
         raise HTTPException(status_code=404, detail="Authentication is not enabled")
 
-    client_ip = request.client.host if request.client else "unknown"
+    client_ip = _client_ip(request, cfg.trusted_proxies)
     if auth.is_locked_out(client_ip):
         raise HTTPException(
             status_code=429, detail="Too many failed attempts. Try again later."
@@ -623,6 +677,7 @@ async def api_auth_login(req: LoginRequest, request: Request):
             max_age=auth.SESSION_TTL_S,
             httponly=True,
             samesite="lax",
+            secure=tls_enabled(cfg),
             path="/",
         )
         return response
@@ -656,6 +711,36 @@ def _require_gpu(gpu_index: int = 0):
     return gpu, g_state
 
 
+class _ClientIpSource(Protocol):
+    """Structural type for the request objects _client_ip accepts.
+
+    Both Starlette's Request and WebSocket expose these; tests may pass
+    lightweight duck types.
+    """
+
+    client: Any
+    headers: Any
+
+
+def _client_ip(request: _ClientIpSource, trusted_proxies: list[str]) -> str:
+    """Best-effort client IP for the login lockout.
+
+    When the direct peer is a configured trusted proxy (e.g. a TLS
+    reverse proxy), use the rightmost X-Forwarded-For entry that is not
+    itself a trusted proxy. Otherwise use the direct peer address —
+    X-Forwarded-For is spoofable, so it is only honoured for peers the
+    operator explicitly listed in ``trusted_proxies``.
+    """
+    peer = request.client.host if request.client else "unknown"
+    if not trusted_proxies or peer not in trusted_proxies:
+        return peer
+    hops = [h.strip() for h in request.headers.get("x-forwarded-for", "").split(",")]
+    for hop in reversed(hops):
+        if hop and hop not in trusted_proxies:
+            return hop
+    return peer
+
+
 # ── REST endpoints ────────────────────────────────────────────────────────────
 
 
@@ -831,6 +916,17 @@ def _persist_fan_curves(fan_curves: dict) -> None:
     _persist_config_field("fan_curves", fan_curves if fan_curves else None)
 
 
+def _persist_power_cap_modes(modes: dict[str, str]) -> None:
+    """Persist the per-GPU experimental power-cap mode dict to config.json."""
+    _persist_config_field("power_cap_modes", modes if modes else None)
+
+
+def _power_cap_mode(cfg: Config, gpu_index: int) -> str:
+    """Return the effective power-cap mode for a GPU ("nvml" or "ioctl")."""
+    mode = cfg.power_cap_modes.get(_gpu_stable_key(gpu_index), "nvml")
+    return mode if mode in ("nvml", "ioctl") else "nvml"
+
+
 @app.get("/api/profiles")
 async def api_profiles(gpu_index: int = 0):
     """List saved native profiles, the active profile name, and the auto-load profile name."""
@@ -858,13 +954,15 @@ async def api_profile_save(req: ProfileSaveRequest, gpu_index: int = 0):
     curve_deltas = {str(p.index): p.delta_khz for p in state.points if p.delta_khz != 0}
 
     try:
-        power_info = await _run(get_power_limit, gpu_index)
+        mode = _power_cap_mode(cfg, gpu_index)
+        power_info = await _run(get_power_limit, gpu_index, mode)
         offsets = await _run(get_clock_offsets, gpu_index)
         power_limit_w = power_info.get("power_limit_w")
         mem_offset_mhz = offsets.get("mem_offset_mhz")
     except Exception:
         power_limit_w = None
         mem_offset_mhz = None
+        mode = "nvml"
 
     data = ProfileData(
         name=req.name,
@@ -872,7 +970,11 @@ async def api_profile_save(req: ProfileSaveRequest, gpu_index: int = 0):
         curve_deltas=curve_deltas,
         mem_offset_mhz=mem_offset_mhz,
         power_limit_w=power_limit_w,
+        power_cap_mode=mode,
         fan_curve=g_state.get("fan_curve") if g_state.get("fan_curve_active") else None,
+        fan_targets=g_state.get("fan_targets")
+        if g_state.get("fan_curve_active")
+        else None,
     )
     filepath = await _run(save_profile, cfg.profile_dir, data)
     g_state["active_profile"] = req.name
@@ -989,7 +1091,8 @@ async def _apply_profile(name: str, gpu_index: int = 0) -> list[str]:
             errs.append(f"Mem offset: {msg}")
 
     if profile.power_limit_w is not None:
-        ok, msg = await _run(set_power_limit, profile.power_limit_w, gpu_index)
+        mode = profile.power_cap_mode or "nvml"
+        ok, msg = await _run(set_power_limit, profile.power_limit_w, gpu_index, mode)
         if not ok:
             errs.append(f"Power limit: {msg}")
 
@@ -1024,7 +1127,7 @@ async def _apply_profile(name: str, gpu_index: int = 0) -> list[str]:
         if not ok:
             errs.append(f"Fan curve: {msg}")
         else:
-            await _activate_fan_curve(gpu_index, profile.fan_curve)
+            await _activate_fan_curve(gpu_index, profile.fan_curve, profile.fan_targets)
     elif g_state.get("fan_curve_active"):
         await _deactivate_fan_curve(gpu_index, reset_hardware=True)
 
@@ -1118,7 +1221,9 @@ async def api_config_update(req: ConfigUpdateRequest):
 @app.get("/api/limits")
 async def api_limits(gpu_index: int = 0):
     """Current performance limits: power and clock offsets."""
-    power = await _run(get_power_limit, gpu_index)
+    cfg: Config = _state["config"]
+    mode = _power_cap_mode(cfg, gpu_index)
+    power = await _run(get_power_limit, gpu_index, mode)
     offsets = await _run(get_clock_offsets, gpu_index)
     mem_off_range = await _run(get_mem_offset_range, gpu_index)
     return {
@@ -1132,10 +1237,36 @@ async def api_limits(gpu_index: int = 0):
 async def api_limits_update(req: LimitsRequest, gpu_index: int = 0):
     """Update performance limits."""
     g_state = _get_gpu_state(gpu_index)
+    cfg: Config = _state["config"]
     errs = []
 
+    if req.power_cap_mode is not None:
+        if req.power_cap_mode not in ("nvml", "ioctl"):
+            raise HTTPException(
+                status_code=400, detail="power_cap_mode must be 'nvml' or 'ioctl'"
+            )
+        if req.power_cap_mode == "ioctl":
+            # Verify the GPU actually exposes the RM interface before enabling,
+            # so a client can't lock a GPU into a mode where every power
+            # operation fails (ioctl mode has no NVML fallback by design).
+            info = await _run(get_power_limit, gpu_index, "ioctl")
+            if not info.get("rm_power_supported"):
+                raise HTTPException(
+                    status_code=409,
+                    detail="Experimental RM power control is not supported "
+                    "on this GPU/driver",
+                )
+        key = _gpu_stable_key(gpu_index)
+        if req.power_cap_mode == "nvml":
+            cfg.power_cap_modes.pop(key, None)
+        else:
+            cfg.power_cap_modes[key] = "ioctl"
+        _persist_power_cap_modes(cfg.power_cap_modes)
+
+    mode = _power_cap_mode(cfg, gpu_index)
+
     if req.power_limit_w is not None:
-        ok, msg = await _run(set_power_limit, req.power_limit_w, gpu_index)
+        ok, msg = await _run(set_power_limit, req.power_limit_w, gpu_index, mode)
         if not ok:
             errs.append(f"Power Limit: {msg}")
 
@@ -1198,12 +1329,17 @@ async def _update_offsets_and_broadcast(gpu_index: int) -> None:
 async def api_limits_reset(gpu_index: int = 0):
     """Reset power limit to hardware default and memory clock offset to 0."""
     g_state = _get_gpu_state(gpu_index)
+    cfg: Config = _state["config"]
     errs = []
 
-    power = await _run(get_power_limit, gpu_index)
+    # Reset uses the GPU's current mode: in ioctl mode the default is
+    # restored through the RM route (which can also restore a previous
+    # below-VBIOS-minimum cap).
+    mode = _power_cap_mode(cfg, gpu_index)
+    power = await _run(get_power_limit, gpu_index, mode)
     default_w = power.get("default_power_limit_w")
     if default_w is not None:
-        ok, msg = await _run(set_power_limit, default_w, gpu_index)
+        ok, msg = await _run(set_power_limit, default_w, gpu_index, mode)
         if not ok:
             errs.append(f"Power Limit: {msg}")
 
@@ -1226,7 +1362,7 @@ async def api_limits_reset(gpu_index: int = 0):
 
 @app.get("/api/fans")
 async def api_fans(gpu_index: int = 0):
-    """Current fan state: fan %, curve, and whether curve control is active."""
+    """Current fan state: per-fan %, curve, and whether curve control is active."""
     _get_gpu_state(gpu_index)
     g_state = _state["gpus"][gpu_index]
     info = await _run(get_fan_info, gpu_index)
@@ -1236,12 +1372,16 @@ async def api_fans(gpu_index: int = 0):
         "fan_mode": "curve" if curve_active else "auto",
         "curve": g_state.get("fan_curve"),
         "curve_active": curve_active,
+        "fan_targets": g_state.get("fan_targets"),
     }
 
 
 @app.post("/api/fans")
 async def api_fans_update(req: FanCurveRequest, gpu_index: int = 0):
-    """Set or update the fan curve. Starts the fan control poller."""
+    """Set or update the fan curve. Starts the fan control poller.
+
+    req.fans selects which fans the curve drives (None = all fans).
+    """
     g_state = _get_gpu_state(gpu_index)
 
     curve_data = [{"temp_c": p.temp_c, "fan_pct": p.fan_pct} for p in req.curve]
@@ -1249,6 +1389,8 @@ async def api_fans_update(req: FanCurveRequest, gpu_index: int = 0):
     if not ok:
         raise HTTPException(status_code=400, detail=msg)
 
+    fans = sorted(set(req.fans)) if req.fans is not None else None
+
     # Test that fan control is available on this GPU, probing with the
     # target for the *current* temperature so the fan is never briefly
     # set to an inappropriate speed.
@@ -1261,14 +1403,14 @@ async def api_fans_update(req: FanCurveRequest, gpu_index: int = 0):
         )
         target = interpolate_fan_speed(curve_data, test_temp)
         if target is not None:
-            fan_ok, fan_msg = await _run(set_fan_speed, gpu_index, target)
+            fan_ok, fan_msg = await _run(set_fan_speed, gpu_index, target, fans)
             if not fan_ok:
                 raise HTTPException(
                     status_code=500, detail=f"Fan control not available: {fan_msg}"
                 )
 
     # Activate the curve (starts the poller) and persist it so it survives restarts.
-    await _activate_fan_curve(gpu_index, curve_data)
+    await _activate_fan_curve(gpu_index, curve_data, fans)
 
     return {"ok": True}
 
@@ -1287,10 +1429,14 @@ async def api_fans_reset(gpu_index: int = 0):
 
 @app.post("/api/fans/speed")
 async def api_fans_speed(req: FanSpeedRequest, gpu_index: int = 0):
-    """One-shot set fan to an exact percentage (bypasses curve)."""
+    """One-shot set fan(s) to an exact percentage (bypasses curve).
+
+    req.fan selects a single fan index; None sets all fans.
+    """
     _get_gpu_state(gpu_index)
     pct = max(0, min(100, req.fan_pct))
-    ok, msg = await _run(set_fan_speed, gpu_index, pct)
+    fans = [req.fan] if req.fan is not None else None
+    ok, msg = await _run(set_fan_speed, gpu_index, pct, fans)
     if not ok:
         raise HTTPException(status_code=500, detail=msg)
     return {"ok": True}
@@ -1340,10 +1486,10 @@ async def api_curve_write(req: WriteRequest, gpu_index: int = 0):
 
     vfp_state, _ = await _run(read_curve, gpu, g_state["gpu_name"])
 
-    effective_limit = (
-        req.max_delta_khz if req.max_delta_khz is not None else cfg.max_delta_khz
-    )
-    errors = validate_write(req.deltas, effective_limit)
+    # The safety cap is always the server-side config value — clients cannot
+    # raise it per request (shared systems must not let one user override the
+    # hardware safety limit). Raise it in /etc/nvcurve/config.json if needed.
+    errors = validate_write(req.deltas, cfg.max_delta_khz)
     if errors:
         raise HTTPException(status_code=400, detail={"errors": errors})
 
@@ -1394,10 +1540,8 @@ async def api_curve_write_global(req: GlobalOffsetRequest, gpu_index: int = 0):
         raise HTTPException(status_code=500, detail="Failed to read curve")
 
     all_deltas = {p.index: req.delta_khz for p in vfp_state.points if p.domain == "gpu"}
-    effective_limit = (
-        req.max_delta_khz if req.max_delta_khz is not None else cfg.max_delta_khz
-    )
-    errors = validate_write(all_deltas, effective_limit)
+    # Safety cap is the server-side config value only (see api_curve_write).
+    errors = validate_write(all_deltas, cfg.max_delta_khz)
     if errors:
         raise HTTPException(status_code=400, detail={"errors": errors})
 
@@ -1538,10 +1682,21 @@ async def api_curve_verify(req: VerifyRequest, gpu_index: int = 0):
 
 @app.post("/api/shutdown")
 async def api_shutdown():
-    """Gracefully shut down the server process."""
+    """Gracefully shut down the server process.
+
+    Disabled when ``allow_api_shutdown`` is false in the config — on shared
+    systems stop the service via systemd instead.
+    """
     import os
     import signal
 
+    cfg: Config = _state["config"]
+    if not cfg.allow_api_shutdown:
+        raise HTTPException(
+            status_code=403,
+            detail="API shutdown is disabled (allow_api_shutdown: false)",
+        )
+
     loop = asyncio.get_running_loop()
     loop.call_later(0.1, lambda: os.kill(os.getpid(), signal.SIGTERM))
     return {"ok": True}
@@ -1728,7 +1883,15 @@ async def serve_spa(catchall: str):
     if not os.path.isdir(_dist_dir):
         return {"error": "Frontend not built. Run pnpm build in frontend/."}
 
-    path = os.path.join(_dist_dir, catchall)
+    # Contain the resolved path inside the dist directory. The raw URL path
+    # can carry encoded ".." segments (e.g. /%2e%2e/etc/passwd) that would
+    # otherwise escape the dist dir via os.path.join — an unauthenticated
+    # arbitrary-file-read since the server runs as root.
+    base = os.path.realpath(_dist_dir)
+    path = os.path.realpath(os.path.join(_dist_dir, catchall))
+    if path != base and not path.startswith(base + os.sep):
+        raise HTTPException(status_code=404, detail="Not Found")
+
     if os.path.isfile(path) and catchall:
         return FileResponse(path)
 
@@ -1754,8 +1917,14 @@ def run(
     gpu_index: int = 0,
     config: Config = default_config,
     open_browser: bool = False,
+    ssl_certfile: str | None = None,
+    ssl_keyfile: str | None = None,
 ) -> None:
-    """Start the uvicorn server. Blocking."""
+    """Start the uvicorn server. Blocking.
+
+    When both ssl_certfile and ssl_keyfile are given (either here or in the
+    config), the server serves HTTPS and the session cookie is Secure.
+    """
     import socket
     import threading
 
@@ -1763,6 +1932,34 @@ def run(
 
     _state["config"] = config
 
+    # CLI flags take precedence over config values.
+    certfile = ssl_certfile or config.ssl_certfile
+    keyfile = ssl_keyfile or config.ssl_keyfile
+    if certfile:
+        config.ssl_certfile = certfile
+    if keyfile:
+        config.ssl_keyfile = keyfile
+    tls = bool(certfile and keyfile)
+
+    # Fail fast on a bad TLS configuration — otherwise uvicorn dies at
+    # startup and (in daemon mode) the error is only visible in the server
+    # log while `serve status` reports "not running".
+    tls = False
+    if certfile and keyfile:
+        missing = [
+            f"{label} ({path})"
+            for label, path in (("certificate", certfile), ("key", keyfile))
+            if not os.path.isfile(path)
+        ]
+        if missing:
+            print(f"Error: TLS file(s) not found: {', '.join(missing)}")
+            print(
+                "Fix the path (nvcurve service configure --ssl-certfile/--ssl-keyfile) "
+                "or disable TLS (--no-ssl)."
+            )
+            return
+        tls = True
+
     # Suppress noisy websockets keepalive ping-timeout tracebacks — these are
     # normal disconnection events (browser tab closed, network hiccup) and
     # logging them at ERROR level creates false alarm noise.
@@ -1780,7 +1977,7 @@ def run(
             )
             return
 
-    url = f"http://{host}:{port}"
+    url = f"{'https' if tls else 'http'}://{host}:{port}"
 
     # Print banner *before* uvicorn starts so it appears above uvicorn's own output.
     # GPU name is populated by the lifespan; we omit it here since the server
@@ -1795,4 +1992,12 @@ def run(
     if open_browser and not _DEV_PORT:
         threading.Timer(1.2, lambda: _open_browser_as_user(url)).start()
 
-    uvicorn.run(app, host=host, port=port, log_level="warning", access_log=False)
+    uvicorn.run(
+        app,
+        host=host,
+        port=port,
+        log_level="warning",
+        access_log=False,
+        ssl_certfile=certfile if tls else None,
+        ssl_keyfile=keyfile if tls else None,
+    )

pyproject.toml

@@ -19,9 +19,20 @@ dependencies = [
 [project.scripts]
 nvcurve = "nvcurve.cli:main"
 
+[dependency-groups]
+dev = [
+    "hatchling",  # enables local `hatch build` and resolves hatch_build.py imports
+]
+
+[tool.hatch.build.hooks.custom]
+
 [tool.hatch.build.targets.wheel]
 packages = ["nvcurve"]
 
+# The custom build hook (hatch_build.py) compiles the React frontend when
+# frontend/dist is missing or stale, so `uv tool install git+<repo-url>` works
+# as a single command. It runs for both wheel and sdist builds.
+
 [tool.hatch.build.targets.wheel.force-include]
 "frontend/dist" = "nvcurve/frontend/dist"
 

scripts/nv_vfcurve_rw.py

@@ -55,20 +55,20 @@ Key findings:
 See NvAPI_VF_Curve_Documentation.md for full technical details.
 """
 
+import argparse
 import ctypes
-import struct
-import sys
 import json
 import os
+import struct
+import sys
 import time
-import argparse
 from datetime import datetime
-from typing import Optional, List, Tuple, Set, Dict
 
 # ═══════════════════════════════════════════════════════════════════════════
 # NvAPI bootstrap
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def load_nvapi():
     """Load libnvidia-api.so from the NVIDIA driver."""
     for name in ("libnvidia-api.so", "libnvidia-api.so.1"):
@@ -145,23 +145,20 @@ def nvcall_raw(fid: int, gpu, buf: ctypes.Array):
 
 FUNC = {
     # Bootstrap
-    "Initialize":          0x0150E828,
-    "EnumPhysicalGPUs":    0xE5AC921F,
-    "GetFullName":         0xCEEE8E9F,
-
+    "Initialize": 0x0150E828,
+    "EnumPhysicalGPUs": 0xE5AC921F,
+    "GetFullName": 0xCEEE8E9F,
     # V/F curve (read)
-    "GetVFPCurve":         0x21537AD4,  # ClkVfPointsGetStatus
-    "GetClockBoostMask":   0x507B4B59,  # ClkVfPointsGetInfo
-    "GetClockBoostTable":  0x23F1B133,  # ClkVfPointsGetControl
-    "GetCurrentVoltage":   0x465F9BCF,  # ClientVoltRailsGetStatus
+    "GetVFPCurve": 0x21537AD4,  # ClkVfPointsGetStatus
+    "GetClockBoostMask": 0x507B4B59,  # ClkVfPointsGetInfo
+    "GetClockBoostTable": 0x23F1B133,  # ClkVfPointsGetControl
+    "GetCurrentVoltage": 0x465F9BCF,  # ClientVoltRailsGetStatus
     "GetClockBoostRanges": 0x64B43A6A,  # ClkDomainsGetInfo
-
     # Additional read
-    "GetPerfLimits":       0xE440B867,  # PerfClientLimitsGetStatus
+    "GetPerfLimits": 0xE440B867,  # PerfClientLimitsGetStatus
     "GetVoltBoostPercent": 0x9DF23CA1,  # ClientVoltRailsGetControl
-
     # Write
-    "SetClockBoostTable":  0x0733E009,  # ClkVfPointsSetControl
+    "SetClockBoostTable": 0x0733E009,  # ClkVfPointsSetControl
 }
 
 # ═══════════════════════════════════════════════════════════════════════════
@@ -170,33 +167,33 @@ FUNC = {
 # ═══════════════════════════════════════════════════════════════════════════
 
 # GetVFPCurve (0x21537AD4)
-VFP_SIZE     = 0x1C28
-VFP_BASE     = 0x48
-VFP_STRIDE   = 0x1C  # 28 bytes
+VFP_SIZE = 0x1C28
+VFP_BASE = 0x48
+VFP_STRIDE = 0x1C  # 28 bytes
 VFP_MAX_ENTRIES = (VFP_SIZE - VFP_BASE) // VFP_STRIDE  # 255
 
 # Get/SetClockBoostTable (0x23F1B133 / 0x0733E009)
-CT_SIZE      = 0x2420
-CT_BASE      = 0x44
-CT_STRIDE    = 0x24  # 36 bytes
+CT_SIZE = 0x2420
+CT_BASE = 0x44
+CT_STRIDE = 0x24  # 36 bytes
 CT_DELTA_OFF = 0x14  # freqDelta offset within entry
 CT_MAX_ENTRIES = (CT_SIZE - CT_BASE) // CT_STRIDE  # 255
 
 # GetClockBoostMask (0x507B4B59)
-MASK_SIZE    = 0x182C
+MASK_SIZE = 0x182C
 
 # Other structs
-VOLT_SIZE    = 0x004C
-RANGES_SIZE  = 0x0928
-PERF_SIZE    = 0x030C
-VBOOST_SIZE  = 0x0028
+VOLT_SIZE = 0x004C
+RANGES_SIZE = 0x0928
+PERF_SIZE = 0x030C
+VBOOST_SIZE = 0x0028
 
 # Mask location within VFP/CT structs
-MASK_OFFSET  = 0x04
-MASK_BYTES   = 32    # 256 bits — covers up to 256 points
+MASK_OFFSET = 0x04
+MASK_BYTES = 32  # 256 bits — covers up to 256 points
 
 # Safety constants
-MAX_DELTA_KHZ = 300_000     # ±300 MHz hard cap for safety
+MAX_DELTA_KHZ = 300_000  # ±300 MHz hard cap for safety
 
 SNAPSHOT_DIR = os.path.expanduser("~/.cache/nv_vfcurve")
 
@@ -205,6 +202,7 @@ SNAPSHOT_DIR = os.path.expanduser("~/.cache/nv_vfcurve")
 # GPU initialization
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def init_gpu() -> tuple:
     """Initialize NvAPI, enumerate GPUs, return (handle, name)."""
     init_fn = nvfunc(FUNC["Initialize"], 0)
@@ -236,18 +234,20 @@ def init_gpu() -> tuple:
 # also distinguishes GPU core vs memory clock domains.
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 class BoostMask:
     """Parsed GetClockBoostMask data.
 
     Provides the raw mask bytes for copying into other calls, plus
     parsed per-entry enabled info for filtering.
     """
+
     def __init__(self, raw: bytes):
         self.raw = raw
         self.size = len(raw)
 
         # The mask field at offset 0x04, 16 bytes — same position as in VFP/CT structs
-        self.mask_bytes = raw[MASK_OFFSET:MASK_OFFSET + MASK_BYTES]
+        self.mask_bytes = raw[MASK_OFFSET : MASK_OFFSET + MASK_BYTES]
 
         self.entries = []
         self._parse_entries()
@@ -260,7 +260,7 @@ class BoostMask:
             enabled = bool(self.mask_bytes[byte_idx] & (1 << bit_idx))
             self.entries.append({"index": i, "enabled": enabled})
 
-    def get_enabled_indices(self) -> List[int]:
+    def get_enabled_indices(self) -> list[int]:
         """Return list of point indices that are enabled in the mask."""
         return [e["index"] for e in self.entries if e["enabled"]]
 
@@ -273,12 +273,13 @@ class BoostMask:
             buf[offset + i] = self.mask_bytes[i]
 
 
-def read_boost_mask(gpu) -> Tuple[Optional[BoostMask], str]:
+def read_boost_mask(gpu) -> tuple[BoostMask | None, str]:
     """Read the clock boost mask — the canonical source of active point info.
 
     Per nvapioc, this mask must be copied into VFP and ClockBoostTable calls.
     Using all-0xFF works on some GPUs (Blackwell) but fails on others (Pascal).
     """
+
     def fill(buf):
         for i in range(MASK_OFFSET, MASK_OFFSET + MASK_BYTES):
             buf[i] = 0xFF
@@ -294,20 +295,22 @@ def read_boost_mask(gpu) -> Tuple[Optional[BoostMask], str]:
 # Point classification — GPU core vs memory
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 class CurveInfo:
     """Holds classified point information for the GPU's V/F curve.
 
     Combines data from GetClockBoostMask, GetVFPCurve, and GetClockBoostTable
     to determine which points are GPU core and which are memory.
     """
+
     def __init__(self):
-        self.gpu_points: List[int] = []       # GPU core V/F point indices
-        self.mem_points: List[int] = []       # Memory V/F point indices
-        self.total_points: int = 0            # Total populated entries
-        self.mask: Optional[BoostMask] = None
+        self.gpu_points: list[int] = []  # GPU core V/F point indices
+        self.mem_points: list[int] = []  # Memory V/F point indices
+        self.total_points: int = 0  # Total populated entries
+        self.mask: BoostMask | None = None
 
     @staticmethod
-    def build(gpu, mask: Optional[BoostMask] = None) -> 'CurveInfo':
+    def build(gpu, mask: BoostMask | None = None) -> "CurveInfo":
         """Classify all points by reading CT field_00 and VFP data.
 
         field_00 == 0: GPU core data point
@@ -340,7 +343,7 @@ class CurveInfo:
             has_vfp_data = False
             if vfp_points and i < len(vfp_points):
                 f, v = vfp_points[i]
-                has_vfp_data = (f > 0 or v > 0)
+                has_vfp_data = f > 0 or v > 0
 
             has_ct_data = False
             for j in range(9):
@@ -378,13 +381,15 @@ class CurveInfo:
 # Data readers (mask-aware)
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def _fill_mask_from_boost(buf, mask: BoostMask):
     """Copy boost mask into buffer."""
     mask.copy_mask_into(buf)
 
 
-def _read_vfp_with_mask(gpu, mask: Optional[BoostMask]) -> Optional[List[Tuple[int, int]]]:
+def _read_vfp_with_mask(gpu, mask: BoostMask | None) -> list[tuple[int, int]] | None:
     """Read VFP curve using the canonical boost mask."""
+
     def fill(buf):
         _fill_mask_from_boost(buf, mask)
 
@@ -403,8 +408,9 @@ def _read_vfp_with_mask(gpu, mask: Optional[BoostMask]) -> Optional[List[Tuple[i
     return points
 
 
-def _read_clock_table_raw_with_mask(gpu, mask: Optional[BoostMask]) -> Optional[bytes]:
+def _read_clock_table_raw_with_mask(gpu, mask: BoostMask | None) -> bytes | None:
     """Read raw ClockBoostTable using the canonical boost mask."""
+
     def fill(buf):
         _fill_mask_from_boost(buf, mask)
 
@@ -412,13 +418,14 @@ def _read_clock_table_raw_with_mask(gpu, mask: Optional[BoostMask]) -> Optional[
     return d if d else None
 
 
-def read_vfp_curve(gpu, mask: Optional[BoostMask] = None,
-                   curve_info: Optional[CurveInfo] = None
-                   ) -> Tuple[Optional[List[Tuple[int, int]]], str]:
+def read_vfp_curve(
+    gpu, mask: BoostMask | None = None, curve_info: CurveInfo | None = None
+) -> tuple[list[tuple[int, int]] | None, str]:
     """Read V/F curve (frequency + voltage pairs).
 
     Returns up to 255 entries. Use curve_info to determine which are GPU/mem.
     """
+
     def fill(buf):
         _fill_mask_from_boost(buf, mask)
 
@@ -442,18 +449,20 @@ def read_vfp_curve(gpu, mask: Optional[BoostMask] = None,
     return points, "OK"
 
 
-def read_clock_table_raw(gpu, mask: Optional[BoostMask] = None
-                         ) -> Tuple[Optional[bytes], str]:
+def read_clock_table_raw(
+    gpu, mask: BoostMask | None = None
+) -> tuple[bytes | None, str]:
     """Read the raw ClockBoostTable buffer."""
+
     def fill(buf):
         _fill_mask_from_boost(buf, mask)
 
     return nvcall(FUNC["GetClockBoostTable"], gpu, CT_SIZE, ver=1, pre_fill=fill)
 
 
-def read_clock_offsets(gpu, mask: Optional[BoostMask] = None,
-                       curve_info: Optional[CurveInfo] = None
-                       ) -> Tuple[Optional[List[int]], str]:
+def read_clock_offsets(
+    gpu, mask: BoostMask | None = None, curve_info: CurveInfo | None = None
+) -> tuple[list[int] | None, str]:
     """Read per-point frequency offsets from the ClockBoostTable."""
     d, err = read_clock_table_raw(gpu, mask)
     if not d:
@@ -482,14 +491,18 @@ def read_clock_entry_full(data: bytes, point: int) -> dict:
     for j in range(9):
         off = base + j * 4
         if j == 5:
-            fields[f"field_{j:02d}_0x{j*4:02X}"] = struct.unpack_from("<i", data, off)[0]
+            fields[f"field_{j:02d}_0x{j * 4:02X}"] = struct.unpack_from(
+                "<i", data, off
+            )[0]
         else:
-            fields[f"field_{j:02d}_0x{j*4:02X}"] = struct.unpack_from("<I", data, off)[0]
+            fields[f"field_{j:02d}_0x{j * 4:02X}"] = struct.unpack_from(
+                "<I", data, off
+            )[0]
     fields["freqDelta_kHz"] = fields["field_05_0x14"]
     return fields
 
 
-def read_voltage(gpu) -> Tuple[Optional[int], str]:
+def read_voltage(gpu) -> tuple[int | None, str]:
     """Read current GPU core voltage in µV."""
     d, err = nvcall(FUNC["GetCurrentVoltage"], gpu, VOLT_SIZE, ver=1)
     if not d:
@@ -497,7 +510,7 @@ def read_voltage(gpu) -> Tuple[Optional[int], str]:
     return struct.unpack_from("<I", d, 0x28)[0], "OK"
 
 
-def read_clock_ranges(gpu) -> Tuple[Optional[dict], str]:
+def read_clock_ranges(gpu) -> tuple[dict | None, str]:
     """Read clock domain min/max offset ranges."""
     d, err = nvcall(FUNC["GetClockBoostRanges"], gpu, RANGES_SIZE, ver=1)
     if not d:
@@ -508,8 +521,7 @@ def read_clock_ranges(gpu) -> Tuple[Optional[dict], str]:
         base = 0x08 + i * 0x48
         if base + 0x48 > len(d):
             break
-        words = [struct.unpack_from("<i", d, base + j)[0]
-                 for j in range(0, 0x48, 4)]
+        words = [struct.unpack_from("<i", d, base + j)[0] for j in range(0, 0x48, 4)]
         domains.append(words)
     return {"num_domains": num, "domains": domains}, "OK"
 
@@ -518,14 +530,17 @@ def read_clock_ranges(gpu) -> Tuple[Optional[dict], str]:
 # Mask bit helpers
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def set_mask_bit(buf, point: int, offset=MASK_OFFSET):
     """Set a single bit in the mask field."""
     byte_idx = offset + (point // 8)
     bit_idx = point % 8
-    buf[byte_idx] = int.from_bytes(buf[byte_idx:byte_idx+1], 'little') | (1 << bit_idx)
+    buf[byte_idx] = int.from_bytes(buf[byte_idx : byte_idx + 1], "little") | (
+        1 << bit_idx
+    )
 
 
-def set_mask_bits(buf, points: Set[int], offset=MASK_OFFSET):
+def set_mask_bits(buf, points: set[int], offset=MASK_OFFSET):
     """Set mask bits for a set of points."""
     for p in points:
         set_mask_bit(buf, p, offset)
@@ -535,11 +550,12 @@ def set_mask_bits(buf, points: Set[int], offset=MASK_OFFSET):
 # Write operations
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def build_write_buffer(
     gpu,
     point_deltas: dict,
-    mask: Optional[BoostMask] = None,
-) -> Tuple[Optional[ctypes.Array], str]:
+    mask: BoostMask | None = None,
+) -> tuple[ctypes.Array | None, str]:
     """Build a SetClockBoostTable buffer with specified per-point deltas.
 
     Strategy: read the current ClockBoostTable (using canonical mask),
@@ -576,9 +592,9 @@ def build_write_buffer(
 def write_clock_offsets(
     gpu,
     point_deltas: dict,
-    mask: Optional[BoostMask] = None,
+    mask: BoostMask | None = None,
     dry_run: bool = False,
-) -> Tuple[int, str]:
+) -> tuple[int, str]:
     """Write per-point frequency offsets via SetClockBoostTable."""
     buf, err = build_write_buffer(gpu, point_deltas, mask)
     if buf is None:
@@ -595,9 +611,10 @@ def write_clock_offsets(
 # Safety checks
 # ═══════════════════════════════════════════════════════════════════════════
 
-def validate_write_request(point_deltas: dict,
-                           curve_info: Optional[CurveInfo] = None
-                           ) -> Optional[str]:
+
+def validate_write_request(
+    point_deltas: dict, curve_info: CurveInfo | None = None
+) -> str | None:
     """Return an error message if the write request is unsafe, else None."""
     mem_points = set()
     if curve_info:
@@ -608,14 +625,18 @@ def validate_write_request(point_deltas: dict,
             return f"Point {point} out of range (0–{CT_MAX_ENTRIES - 1})"
 
         if point in mem_points:
-            return (f"Point {point} is a memory clock entry. "
-                    "Memory offsets use a different mechanism (NVML). "
-                    "Use --force if you really mean it.")
+            return (
+                f"Point {point} is a memory clock entry. "
+                "Memory offsets use a different mechanism (NVML). "
+                "Use --force if you really mean it."
+            )
 
         if abs(delta_khz) > MAX_DELTA_KHZ:
-            return (f"Delta {delta_khz/1000:+.0f} MHz for point {point} exceeds "
-                    f"safety limit of ±{MAX_DELTA_KHZ/1000:.0f} MHz. "
-                    "Use --max-delta to raise the limit if needed.")
+            return (
+                f"Delta {delta_khz / 1000:+.0f} MHz for point {point} exceeds "
+                f"safety limit of ±{MAX_DELTA_KHZ / 1000:.0f} MHz. "
+                "Use --max-delta to raise the limit if needed."
+            )
 
     return None
 
@@ -624,11 +645,12 @@ def validate_write_request(point_deltas: dict,
 # Hex dump utility
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def hexdump(data: bytes, start: int, length: int, cols: int = 16) -> str:
     lines = []
     end = min(start + length, len(data))
     for off in range(start, end, cols):
-        chunk = data[off:off + cols]
+        chunk = data[off : off + cols]
         hx = " ".join(f"{b:02x}" for b in chunk)
         asc = "".join(chr(b) if 32 <= b < 127 else "." for b in chunk)
         lines.append(f"  {off:04x}: {hx:<{cols * 3}}  {asc}")
@@ -639,7 +661,8 @@ def hexdump(data: bytes, start: int, length: int, cols: int = 16) -> str:
 # Snapshot save/restore
 # ═══════════════════════════════════════════════════════════════════════════
 
-def snapshot_save(gpu, gpu_name: str, mask: Optional[BoostMask] = None):
+
+def snapshot_save(gpu, gpu_name: str, mask: BoostMask | None = None):
     """Save the current ClockBoostTable to disk."""
     raw, err = read_clock_table_raw(gpu, mask)
     if not raw:
@@ -674,7 +697,7 @@ def snapshot_save(gpu, gpu_name: str, mask: Optional[BoostMask] = None):
     with open(meta_fname, "w") as f:
         json.dump(meta, f, indent=2)
 
-    print(f"Snapshot saved:")
+    print("Snapshot saved:")
     print(f"  Binary:   {fname}")
     print(f"  Metadata: {meta_fname}")
     print(f"  Size:     {len(raw)} bytes")
@@ -682,7 +705,7 @@ def snapshot_save(gpu, gpu_name: str, mask: Optional[BoostMask] = None):
     return True
 
 
-def snapshot_restore(gpu, mask: Optional[BoostMask] = None, filepath: str = None):
+def snapshot_restore(gpu, mask: BoostMask | None = None, filepath: str = None):
     """Restore a ClockBoostTable snapshot from disk."""
     if filepath is None:
         if not os.path.isdir(SNAPSHOT_DIR):
@@ -730,7 +753,8 @@ def snapshot_restore(gpu, mask: Optional[BoostMask] = None, filepath: str = None
 # Diagnostics
 # ═══════════════════════════════════════════════════════════════════════════
 
-def run_diagnostics(gpu, gpu_name, mask: Optional[BoostMask] = None):
+
+def run_diagnostics(gpu, gpu_name, mask: BoostMask | None = None):
     """Probe all known functions and report results."""
     print(f"GPU: {gpu_name}")
     print()
@@ -739,14 +763,14 @@ def run_diagnostics(gpu, gpu_name, mask: Optional[BoostMask] = None):
     print("=== Function probe ===")
     print()
     probes = [
-        ("GetVFPCurve",         FUNC["GetVFPCurve"],         VFP_SIZE,    1),
-        ("GetClockBoostMask",   FUNC["GetClockBoostMask"],   MASK_SIZE,   1),
-        ("GetClockBoostTable",  FUNC["GetClockBoostTable"],  CT_SIZE,     1),
-        ("GetCurrentVoltage",   FUNC["GetCurrentVoltage"],   VOLT_SIZE,   1),
+        ("GetVFPCurve", FUNC["GetVFPCurve"], VFP_SIZE, 1),
+        ("GetClockBoostMask", FUNC["GetClockBoostMask"], MASK_SIZE, 1),
+        ("GetClockBoostTable", FUNC["GetClockBoostTable"], CT_SIZE, 1),
+        ("GetCurrentVoltage", FUNC["GetCurrentVoltage"], VOLT_SIZE, 1),
         ("GetClockBoostRanges", FUNC["GetClockBoostRanges"], RANGES_SIZE, 1),
-        ("GetPerfLimits",       FUNC["GetPerfLimits"],       PERF_SIZE,   2),
-        ("GetVoltBoostPercent", FUNC["GetVoltBoostPercent"],  VBOOST_SIZE, 1),
-        ("SetClockBoostTable",  FUNC["SetClockBoostTable"],  CT_SIZE,     1),
+        ("GetPerfLimits", FUNC["GetPerfLimits"], PERF_SIZE, 2),
+        ("GetVoltBoostPercent", FUNC["GetVoltBoostPercent"], VBOOST_SIZE, 1),
+        ("SetClockBoostTable", FUNC["SetClockBoostTable"], CT_SIZE, 1),
     ]
     for name, fid, size, ver in probes:
         ptr = QI(fid)
@@ -768,7 +792,9 @@ def run_diagnostics(gpu, gpu_name, mask: Optional[BoostMask] = None):
 
     # Step 3: test reads with the proper mask
     needs_mask_fns = {
-        FUNC["GetVFPCurve"], FUNC["GetClockBoostMask"], FUNC["GetClockBoostTable"]
+        FUNC["GetVFPCurve"],
+        FUNC["GetClockBoostMask"],
+        FUNC["GetClockBoostTable"],
     }
 
     print()
@@ -817,8 +843,10 @@ def run_diagnostics(gpu, gpu_name, mask: Optional[BoostMask] = None):
 # Output formatting
 # ═══════════════════════════════════════════════════════════════════════════
 
-def print_curve(points, offsets, voltage, curve_info: Optional[CurveInfo] = None,
-                full=False):
+
+def print_curve(
+    points, offsets, voltage, curve_info: CurveInfo | None = None, full=False
+):
     """Print formatted V/F curve table."""
     if voltage:
         print(f"Current voltage: {voltage / 1000:.1f} mV")
@@ -845,9 +873,7 @@ def print_curve(points, offsets, voltage, curve_info: Optional[CurveInfo] = None
         for i, (f, v) in enumerate(points):
             if f == 0 and v == 0:
                 continue
-            if i in mem_set:
-                show.append(i)
-            elif f != prev_freq or i == len(points) - 1:
+            if i in mem_set or f != prev_freq or i == len(points) - 1:
                 show.append(i)
             prev_freq = f
 
@@ -882,52 +908,78 @@ def print_curve(points, offsets, voltage, curve_info: Optional[CurveInfo] = None
 
     # Summary
     if curve_info and curve_info.gpu_points:
-        gpu_data = [(points[i][0], points[i][1]) for i in curve_info.gpu_points
-                     if i < len(points) and points[i][0] > 0]
+        gpu_data = [
+            (points[i][0], points[i][1])
+            for i in curve_info.gpu_points
+            if i < len(points) and points[i][0] > 0
+        ]
         if gpu_data:
             freqs = [f for f, v in gpu_data]
             volts = [v for f, v in gpu_data]
             print()
-            print(f"GPU core: {min(freqs)/1000:.0f} – {max(freqs)/1000:.0f} MHz, "
-                  f"{min(volts)/1000:.0f} – {max(volts)/1000:.0f} mV "
-                  f"({len(gpu_data)} points)")
+            print(
+                f"GPU core: {min(freqs) / 1000:.0f} – {max(freqs) / 1000:.0f} MHz, "
+                f"{min(volts) / 1000:.0f} – {max(volts) / 1000:.0f} mV "
+                f"({len(gpu_data)} points)"
+            )
 
     if curve_info and curve_info.mem_points:
-        mem_data = [(points[i][0], points[i][1]) for i in curve_info.mem_points
-                     if i < len(points) and points[i][0] > 0]
+        mem_data = [
+            (points[i][0], points[i][1])
+            for i in curve_info.mem_points
+            if i < len(points) and points[i][0] > 0
+        ]
         if mem_data:
             freqs = [f for f, v in mem_data]
             volts = [v for f, v in mem_data]
-            print(f"Memory:   {min(freqs)/1000:.0f} – {max(freqs)/1000:.0f} MHz, "
-                  f"{min(volts)/1000:.0f} – {max(volts)/1000:.0f} mV "
-                  f"({len(mem_data)} points)")
+            print(
+                f"Memory:   {min(freqs) / 1000:.0f} – {max(freqs) / 1000:.0f} MHz, "
+                f"{min(volts) / 1000:.0f} – {max(volts) / 1000:.0f} mV "
+                f"({len(mem_data)} points)"
+            )
 
     if offsets:
-        gpu_indices = set(curve_info.gpu_points) if curve_info else set(range(len(offsets)))
-        gpu_offsets = [offsets[i] for i in gpu_indices
-                       if i < len(offsets) and offsets[i] != 0]
+        gpu_indices = (
+            set(curve_info.gpu_points) if curve_info else set(range(len(offsets)))
+        )
+        gpu_offsets = [
+            offsets[i] for i in gpu_indices if i < len(offsets) and offsets[i] != 0
+        ]
         if gpu_offsets:
             vals = set(gpu_offsets)
             if len(vals) == 1:
-                print(f"GPU offset: {next(iter(vals))/1000:+.0f} MHz "
-                      f"(uniform across {len(gpu_offsets)} points)")
+                print(
+                    f"GPU offset: {next(iter(vals)) / 1000:+.0f} MHz "
+                    f"(uniform across {len(gpu_offsets)} points)"
+                )
             else:
-                print(f"GPU offsets: {len(gpu_offsets)} points active "
-                      f"(range: {min(vals)/1000:+.0f} to {max(vals)/1000:+.0f} MHz)")
+                print(
+                    f"GPU offsets: {len(gpu_offsets)} points active "
+                    f"(range: {min(vals) / 1000:+.0f} to {max(vals) / 1000:+.0f} MHz)"
+                )
 
 
-def output_json(gpu_name, points, offsets, voltage,
-                curve_info: Optional[CurveInfo] = None):
+def output_json(
+    gpu_name, points, offsets, voltage, curve_info: CurveInfo | None = None
+):
     """Output JSON format."""
     data = {
         "gpu": gpu_name,
         "current_voltage_uV": voltage,
         "layout": {
-            "vfp_curve": {"size": VFP_SIZE, "base": VFP_BASE,
-                          "stride": VFP_STRIDE, "max_entries": VFP_MAX_ENTRIES},
-            "clock_table": {"size": CT_SIZE, "base": CT_BASE,
-                            "stride": CT_STRIDE, "delta_offset": CT_DELTA_OFF,
-                            "max_entries": CT_MAX_ENTRIES},
+            "vfp_curve": {
+                "size": VFP_SIZE,
+                "base": VFP_BASE,
+                "stride": VFP_STRIDE,
+                "max_entries": VFP_MAX_ENTRIES,
+            },
+            "clock_table": {
+                "size": CT_SIZE,
+                "base": CT_BASE,
+                "stride": CT_STRIDE,
+                "delta_offset": CT_DELTA_OFF,
+                "max_entries": CT_MAX_ENTRIES,
+            },
         },
         "curve_info": {
             "gpu_points": curve_info.gpu_points if curve_info else [],
@@ -958,6 +1010,7 @@ def output_json(gpu_name, points, offsets, voltage,
 # Write command handler
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def cmd_write(gpu, gpu_name, args, mask, curve_info):
     """Handle write subcommand."""
     delta_khz = int(args.delta * 1000)
@@ -977,21 +1030,27 @@ def cmd_write(gpu, gpu_name, args, mask, curve_info):
 
     elif args.point is not None:
         point_deltas[args.point] = delta_khz
-        print(f"Target: point {args.point}, delta {args.delta:+.0f} MHz "
-              f"({delta_khz:+d} kHz)")
+        print(
+            f"Target: point {args.point}, delta {args.delta:+.0f} MHz "
+            f"({delta_khz:+d} kHz)"
+        )
 
     elif args.range:
         start, end = args.range
         for i in range(start, end + 1):
             point_deltas[i] = delta_khz
-        print(f"Target: points {start}–{end} ({len(point_deltas)} points), "
-              f"delta {args.delta:+.0f} MHz")
+        print(
+            f"Target: points {start}–{end} ({len(point_deltas)} points), "
+            f"delta {args.delta:+.0f} MHz"
+        )
 
     elif args.glob:
         for i in gpu_points:
             point_deltas[i] = delta_khz
-        print(f"Target: all {len(point_deltas)} GPU core points, "
-              f"delta {args.delta:+.0f} MHz")
+        print(
+            f"Target: all {len(point_deltas)} GPU core points, "
+            f"delta {args.delta:+.0f} MHz"
+        )
 
     else:
         print("Error: specify --point N, --range A-B, --global, or --reset")
@@ -1013,11 +1072,17 @@ def cmd_write(gpu, gpu_name, args, mask, curve_info):
     changed = 0
     for point in sorted(point_deltas.keys()):
         new = point_deltas[point]
-        old = current_offsets[point] if current_offsets and point < len(current_offsets) else 0
+        old = (
+            current_offsets[point]
+            if current_offsets and point < len(current_offsets)
+            else 0
+        )
         if old != new:
             changed += 1
             if changed <= 20:
-                print(f"  Point {point:3d}: {old/1000:+8.0f} MHz → {new/1000:+8.0f} MHz")
+                print(
+                    f"  Point {point:3d}: {old / 1000:+8.0f} MHz → {new / 1000:+8.0f} MHz"
+                )
     if changed > 20:
         print(f"  ... and {changed - 20} more points")
     if changed == 0:
@@ -1036,8 +1101,10 @@ def cmd_write(gpu, gpu_name, args, mask, curve_info):
 
             first_pt = min(point_deltas.keys())
             entry_off = CT_BASE + first_pt * CT_STRIDE
-            print(f"\nEntry for point {first_pt} (offset 0x{entry_off:04X}, "
-                  f"stride 0x{CT_STRIDE:02X}):")
+            print(
+                f"\nEntry for point {first_pt} (offset 0x{entry_off:04X}, "
+                f"stride 0x{CT_STRIDE:02X}):"
+            )
             print(hexdump(bytes(buf), entry_off, CT_STRIDE))
         return
 
@@ -1070,8 +1137,10 @@ def cmd_write(gpu, gpu_name, args, mask, curve_info):
         actual = new_offsets[point] if point < len(new_offsets) else 0
         if actual != expected:
             mismatches += 1
-            print(f"  MISMATCH point {point}: expected {expected/1000:+.0f} MHz, "
-                  f"got {actual/1000:+.0f} MHz")
+            print(
+                f"  MISMATCH point {point}: expected {expected / 1000:+.0f} MHz, "
+                f"got {actual / 1000:+.0f} MHz"
+            )
 
     if mismatches == 0:
         print(f"Verified: all {len(point_deltas)} points match expected values.")
@@ -1083,6 +1152,7 @@ def cmd_write(gpu, gpu_name, args, mask, curve_info):
 # Verify command handler
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def cmd_verify(gpu, gpu_name, args, mask, curve_info):
     """Write-verify-read cycle for a single point or range."""
     delta_khz = int(args.delta * 1000)
@@ -1095,14 +1165,14 @@ def cmd_verify(gpu, gpu_name, args, mask, curve_info):
         print("Error: --point or --range required for verify mode")
         return
 
-    point_deltas = {p: delta_khz for p in points}
+    point_deltas = dict.fromkeys(points, delta_khz)
 
     err = validate_write_request(point_deltas, curve_info)
     if err:
         print(f"Safety check FAILED: {err}")
         return
 
-    print(f"=== Write-Verify Cycle ===")
+    print("=== Write-Verify Cycle ===")
     print(f"GPU: {gpu_name}")
     if curve_info:
         print(f"Curve: {curve_info.describe()}")
@@ -1121,7 +1191,7 @@ def cmd_verify(gpu, gpu_name, args, mask, curve_info):
     for p in points[:5]:
         entry = read_clock_entry_full(before_raw, p) if before_raw else {}
         off_val = before_offsets[p] if p < len(before_offsets) else 0
-        print(f"  Point {p:3d}: freqDelta = {off_val/1000:+8.0f} MHz")
+        print(f"  Point {p:3d}: freqDelta = {off_val / 1000:+8.0f} MHz")
         if entry:
             print(f"    All fields: {entry}")
 
@@ -1156,8 +1226,10 @@ def cmd_verify(gpu, gpu_name, args, mask, curve_info):
         match = "OK" if actual == expected else "MISMATCH"
         if actual != expected:
             all_ok = False
-        print(f"  Point {p:3d}: expected {expected/1000:+8.0f} MHz, "
-              f"got {actual/1000:+8.0f} MHz  [{match}]")
+        print(
+            f"  Point {p:3d}: expected {expected / 1000:+8.0f} MHz, "
+            f"got {actual / 1000:+8.0f} MHz  [{match}]"
+        )
 
     # Step 5: Check for collateral damage
     print()
@@ -1169,8 +1241,10 @@ def cmd_verify(gpu, gpu_name, args, mask, curve_info):
             continue
         if before_offsets[i] != after_offsets[i]:
             collateral += 1
-            print(f"  WARNING: Point {i} changed unexpectedly: "
-                  f"{before_offsets[i]/1000:+.0f} → {after_offsets[i]/1000:+.0f} MHz")
+            print(
+                f"  WARNING: Point {i} changed unexpectedly: "
+                f"{before_offsets[i] / 1000:+.0f} → {after_offsets[i] / 1000:+.0f} MHz"
+            )
     if collateral == 0:
         print("  No unintended changes detected.")
 
@@ -1187,14 +1261,16 @@ def cmd_verify(gpu, gpu_name, args, mask, curve_info):
                     continue
                 if before_entry[key] != after_entry[key]:
                     field_changes += 1
-                    print(f"  Point {p}, {key}: {before_entry[key]} → {after_entry[key]}")
+                    print(
+                        f"  Point {p}, {key}: {before_entry[key]} → {after_entry[key]}"
+                    )
         if field_changes == 0:
             print("  No unknown fields changed.")
 
     # Step 7: Read voltage
     voltage, _ = read_voltage(gpu)
     if voltage:
-        print(f"\nCurrent voltage after write: {voltage/1000:.1f} mV")
+        print(f"\nCurrent voltage after write: {voltage / 1000:.1f} mV")
 
     # Summary
     print()
@@ -1215,6 +1291,7 @@ def cmd_verify(gpu, gpu_name, args, mask, curve_info):
 # Inspect command
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def cmd_inspect(gpu, gpu_name, args, mask, curve_info):
     """Show detailed field-level data for specific points."""
     raw, err = read_clock_table_raw(gpu, mask)
@@ -1246,8 +1323,9 @@ def cmd_inspect(gpu, gpu_name, args, mask, curve_info):
     print(f"GPU: {gpu_name}")
     if curve_info:
         print(f"Curve: {curve_info.describe()}")
-    print(f"ClockBoostTable entry detail (stride=0x{CT_STRIDE:02X}, "
-          f"9 fields × 4 bytes)")
+    print(
+        f"ClockBoostTable entry detail (stride=0x{CT_STRIDE:02X}, 9 fields × 4 bytes)"
+    )
     print()
 
     for p in indices:
@@ -1267,7 +1345,7 @@ def cmd_inspect(gpu, gpu_name, args, mask, curve_info):
         freq_str = ""
         if vfp_points and p < len(vfp_points):
             f, v = vfp_points[p]
-            freq_str = f"  (VFP: {f/1000:.0f} MHz @ {v/1000:.0f} mV)"
+            freq_str = f"  (VFP: {f / 1000:.0f} MHz @ {v / 1000:.0f} mV)"
 
         print(f"Point {p:3d} — buffer offset 0x{off:04X}{domain}{freq_str}")
         for key, val in entry.items():
@@ -1275,8 +1353,10 @@ def cmd_inspect(gpu, gpu_name, args, mask, curve_info):
                 continue
             marker = " ← freqDelta" if "0x14" in key else ""
             if "0x14" in key:
-                print(f"  {key}: {val:12d}  (0x{val & 0xFFFFFFFF:08X})"
-                      f"  = {val/1000:+.0f} MHz{marker}")
+                print(
+                    f"  {key}: {val:12d}  (0x{val & 0xFFFFFFFF:08X})"
+                    f"  = {val / 1000:+.0f} MHz{marker}"
+                )
             else:
                 print(f"  {key}: {val:12d}  (0x{val:08X})")
         print()
@@ -1286,6 +1366,7 @@ def cmd_inspect(gpu, gpu_name, args, mask, curve_info):
 # Read command handler
 # ═══════════════════════════════════════════════════════════════════════════
 
+
 def cmd_read(gpu, gpu_name, args, mask, curve_info):
     """Handle read subcommand."""
     if args.diag:
@@ -1309,10 +1390,13 @@ def cmd_read(gpu, gpu_name, args, mask, curve_info):
     print(f"GPU: {gpu_name}")
 
     if args.raw:
+
         def fill_vfp(buf):
             _fill_mask_from_boost(buf, mask)
-        vfp_raw, _ = nvcall(FUNC["GetVFPCurve"], gpu, VFP_SIZE,
-                             ver=1, pre_fill=fill_vfp)
+
+        vfp_raw, _ = nvcall(
+            FUNC["GetVFPCurve"], gpu, VFP_SIZE, ver=1, pre_fill=fill_vfp
+        )
         ct_raw, _ = read_clock_table_raw(gpu, mask)
 
         if vfp_raw:
@@ -1348,7 +1432,8 @@ def cmd_read(gpu, gpu_name, args, mask, curve_info):
 # Argument parsing
 # ═══════════════════════════════════════════════════════════════════════════
 
-def parse_range(s: str) -> Tuple[int, int]:
+
+def parse_range(s: str) -> tuple[int, int]:
     """Parse 'A-B' into (A, B) tuple."""
     parts = s.split("-")
     if len(parts) != 2:
@@ -1360,7 +1445,9 @@ def parse_range(s: str) -> Tuple[int, int]:
     if a > b:
         raise argparse.ArgumentTypeError(f"Start > end in range: {a}-{b}")
     if a < 0 or b >= CT_MAX_ENTRIES:
-        raise argparse.ArgumentTypeError(f"Range {a}-{b} outside 0–{CT_MAX_ENTRIES - 1}")
+        raise argparse.ArgumentTypeError(
+            f"Range {a}-{b} outside 0–{CT_MAX_ENTRIES - 1}"
+        )
     return (a, b)
 
 
@@ -1390,14 +1477,16 @@ Examples:
 
     # --- read ---
     p_read = sub.add_parser("read", help="Read V/F curve (default)")
-    p_read.add_argument("--full", action="store_true",
-                        help="Show all points including empty slots")
-    p_read.add_argument("--json", action="store_true",
-                        help="JSON output with domain classification")
-    p_read.add_argument("--raw", action="store_true",
-                        help="Include hex dumps")
-    p_read.add_argument("--diag", action="store_true",
-                        help="Probe all functions with mask comparison")
+    p_read.add_argument(
+        "--full", action="store_true", help="Show all points including empty slots"
+    )
+    p_read.add_argument(
+        "--json", action="store_true", help="JSON output with domain classification"
+    )
+    p_read.add_argument("--raw", action="store_true", help="Include hex dumps")
+    p_read.add_argument(
+        "--diag", action="store_true", help="Probe all functions with mask comparison"
+    )
 
     # --- inspect ---
     p_insp = sub.add_parser("inspect", help="Show detailed entry fields")
@@ -1409,30 +1498,42 @@ Examples:
     tgt = p_write.add_mutually_exclusive_group()
     tgt.add_argument("--point", type=int, help="Single point index")
     tgt.add_argument("--range", type=parse_range, help="Point range A-B")
-    tgt.add_argument("--global", dest="glob", action="store_true",
-                     help="All GPU core points")
-    tgt.add_argument("--reset", action="store_true",
-                     help="Reset all GPU core offsets to 0")
-    p_write.add_argument("--delta", type=float, default=0.0,
-                         help="Frequency offset in MHz (e.g. 15, -30)")
-    p_write.add_argument("--dry-run", action="store_true",
-                         help="Preview changes without applying")
-    p_write.add_argument("--force", action="store_true",
-                         help="Allow modifying memory points")
-    p_write.add_argument("--max-delta", type=float, default=300.0,
-                         help="Override safety limit (MHz, default 300)")
+    tgt.add_argument(
+        "--global", dest="glob", action="store_true", help="All GPU core points"
+    )
+    tgt.add_argument(
+        "--reset", action="store_true", help="Reset all GPU core offsets to 0"
+    )
+    p_write.add_argument(
+        "--delta",
+        type=float,
+        default=0.0,
+        help="Frequency offset in MHz (e.g. 15, -30)",
+    )
+    p_write.add_argument(
+        "--dry-run", action="store_true", help="Preview changes without applying"
+    )
+    p_write.add_argument(
+        "--force", action="store_true", help="Allow modifying memory points"
+    )
+    p_write.add_argument(
+        "--max-delta",
+        type=float,
+        default=300.0,
+        help="Override safety limit (MHz, default 300)",
+    )
 
     # --- verify ---
     p_ver = sub.add_parser("verify", help="Write-verify-read cycle")
     p_ver.add_argument("--point", type=int, help="Single point index")
     p_ver.add_argument("--range", type=parse_range, help="Point range A-B")
-    p_ver.add_argument("--delta", type=float, required=True,
-                       help="Frequency offset in MHz")
+    p_ver.add_argument(
+        "--delta", type=float, required=True, help="Frequency offset in MHz"
+    )
 
     # --- snapshot ---
     p_snap = sub.add_parser("snapshot", help="Save/restore ClockBoostTable")
-    p_snap.add_argument("action", choices=["save", "restore"],
-                        help="save or restore")
+    p_snap.add_argument("action", choices=["save", "restore"], help="save or restore")
     p_snap.add_argument("--file", help="Snapshot file path (for restore)")
 
     args = parser.parse_args()

tests/test_rm_power.py

@@ -0,0 +1,355 @@
+"""Unit tests for the RM power-limit interface (fake RM, no hardware).
+
+Standalone (no pytest required):
+
+    python tests/test_rm_power.py
+
+Also works under pytest if available. Ports the test battery from LACT PR
+#1205 (ilya-zlobintsev/LACT): layout discovery, NVML cross-validation,
+write minimality, readback verification, and failure restoration.
+"""
+
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
+
+from nvcurve.hal.rm_power import (  # noqa: E402
+    _CTRL_GPU_GET_ATTACHED_IDS,
+    _CTRL_GPU_GET_ID_INFO_V2,
+    _CTRL_GPU_GET_PCI_INFO,
+    _PWR_GET_CONTROL,
+    _PWR_GET_INFO,
+    _PWR_SET_CONTROL,
+    EXTENDED_LAYOUT,
+    LEGACY_LAYOUT,
+    PciLocation,
+    PowerLimitBounds,
+    RmPowerError,
+    _u32,
+    probe,
+    resolve_gpu_instance,
+    set_limit,
+)
+
+PASS = 0
+FAIL = 0
+
+
+def check(name: str, cond: bool) -> None:
+    global PASS, FAIL
+    if cond:
+        PASS += 1
+        print(f"  PASS  {name}")
+    else:
+        FAIL += 1
+        print(f"  FAIL  {name}")
+
+
+BOUNDS = PowerLimitBounds(min_mw=250_000, default_mw=300_000, max_mw=325_000)
+
+
+class FakeRm:
+    """In-memory fake of the RM power-limit client (both wire layouts)."""
+
+    def __init__(self, layout, current: int) -> None:
+        self.layout = layout
+        self.control = bytearray(layout.control_size)
+        self.control[0:8] = bytes([0xFF, 0, 0, 0, 1, 0, 0, 0])
+        self.control[layout.request_at - 4 : layout.request_at] = bytes(
+            [0x67, 0x67, 0, 0]
+        )
+        self.control[layout.request_at : layout.request_at + 4] = current.to_bytes(
+            4, "little"
+        )
+        self.control[layout.client_at] = 0xFE
+        self.reads: list[tuple[int, int]] = []
+        self.writes: list[bytes] = []
+        self.fail_first_write = False
+        self.fail_readback = False
+        self.fail_restore = False
+
+    def query(self, cmd: int, data: bytearray) -> None:
+        if cmd == _PWR_GET_INFO:
+            self.reads.append((cmd, len(data)))
+            if len(data) != self.layout.info_size:
+                raise RmPowerError("Unsupported INFO size")
+            data[0:8] = bytes([0xFF, 0, 0, 0, 1, 0, 0, 0])
+            for index, value in enumerate([250_000, 300_000, 325_000]):
+                offset = self.layout.info_min_at + 4 * index
+                data[offset : offset + 4] = value.to_bytes(4, "little")
+        elif cmd == _PWR_GET_CONTROL:
+            self.reads.append((cmd, len(data)))
+            if len(data) != self.layout.control_size:
+                raise RmPowerError("Unsupported CONTROL size")
+            if data[self.layout.client_at] != 0xFE:
+                raise AssertionError("unexpected client selector on GET")
+            if self.fail_readback and len(self.writes) == 1:
+                raise RmPowerError("readback unavailable")
+            data[:] = self.control
+        elif cmd == _PWR_SET_CONTROL:
+            if len(data) != self.layout.control_size:
+                raise AssertionError("bad SET size")
+            if data[4:8] != (1).to_bytes(4, "little"):
+                raise AssertionError("bad SET mask")
+            if data[self.layout.client_at] != 0xFE:
+                raise AssertionError("bad SET client selector")
+            # Only the request field may differ from the current state.
+            for i, (a, b) in enumerate(zip(data, self.control, strict=True)):
+                if self.layout.request_at <= i < self.layout.request_at + 4:
+                    continue
+                if a != b:
+                    raise AssertionError(f"SET modified byte {i:#x}")
+            self.writes.append(bytes(data))
+            if self.fail_restore and len(self.writes) > 1:
+                raise RmPowerError("restore unavailable")
+            self.control[:] = data
+            if self.fail_first_write and len(self.writes) == 1:
+                raise RmPowerError("SET failed after modifying hardware")
+        else:
+            raise AssertionError(f"unexpected command {cmd:#x}")
+
+
+def test_detects_both_layouts_with_gets_without_a_driver_version() -> None:
+    for layout in (EXTENDED_LAYOUT, LEGACY_LAYOUT):
+        rm = FakeRm(layout, 250_000)
+        support = probe(BOUNDS, 250_000, rm.query)
+        check(
+            f"{layout.name}: detected",
+            support.bounds == BOUNDS and support.layout == layout,
+        )
+        expected = (
+            [(_PWR_GET_INFO, 0x924), (_PWR_GET_CONTROL, 0x328)]
+            if layout == EXTENDED_LAYOUT
+            else [
+                (_PWR_GET_INFO, 0x924),
+                (_PWR_GET_INFO, 0x488),
+                (_PWR_GET_CONTROL, 0x188),
+            ]
+        )
+        check(f"{layout.name}: GETs only, expected sequence", rm.reads == expected)
+        check(f"{layout.name}: no writes during discovery", rm.writes == [])
+
+
+def test_unknown_layout_and_nvml_mismatches_never_write() -> None:
+    calls: list[tuple[int, int]] = []
+
+    def failing(cmd: int, data: bytearray) -> None:
+        calls.append((cmd, len(data)))
+        raise RmPowerError("Unsupported payload")
+
+    try:
+        probe(BOUNDS, 250_000, failing)
+        check("unknown layout rejected", False)
+    except RmPowerError:
+        check("unknown layout rejected", True)
+    check(
+        "unknown layout: only GETs attempted",
+        calls == [(_PWR_GET_INFO, 0x924), (_PWR_GET_INFO, 0x488)],
+    )
+
+    for layout in (EXTENDED_LAYOUT, LEGACY_LAYOUT):
+        rm = FakeRm(layout, 250_000)
+        try:
+            probe(BOUNDS, 300_000, rm.query)
+            check(f"{layout.name}: current mismatch rejected", False)
+        except RmPowerError:
+            check(f"{layout.name}: current mismatch rejected", True)
+        other_bounds = PowerLimitBounds(
+            min_mw=BOUNDS.min_mw, default_mw=BOUNDS.default_mw, max_mw=350_000
+        )
+        try:
+            probe(other_bounds, 250_000, rm.query)
+            check(f"{layout.name}: bounds mismatch rejected", False)
+        except RmPowerError:
+            check(f"{layout.name}: bounds mismatch rejected", True)
+        check(f"{layout.name}: no writes on mismatch", rm.writes == [])
+
+
+def test_rejects_unrecognized_headers_masks_and_client_values() -> None:
+    for layout in (EXTENDED_LAYOUT, LEGACY_LAYOUT):
+        for at, value in [(0, 0), (4, 3), (layout.client_at, 0xF8)]:
+            rm = FakeRm(layout, 250_000)
+            rm.control[at] = value
+            try:
+                probe(BOUNDS, 250_000, rm.query)
+                check(f"{layout.name}: bad header/client rejected", False)
+            except RmPowerError:
+                check(f"{layout.name}: bad header/client rejected", True)
+            check(f"{layout.name}: no writes on bad header", rm.writes == [])
+        for current in (0, 0xFFFFFFFF):
+            rm = FakeRm(layout, current)
+            try:
+                probe(BOUNDS, current, rm.query)
+                check(f"{layout.name}: empty request rejected", False)
+            except RmPowerError:
+                check(f"{layout.name}: empty request rejected", True)
+    # The extended layout has additional mask words. Accepting only its low
+    # word would allow an unexpected client to be included in a later SET.
+    rm = FakeRm(EXTENDED_LAYOUT, 250_000)
+    rm.control[8] = 1
+    try:
+        probe(BOUNDS, 250_000, rm.query)
+        check("extended: nonzero mask word rejected", False)
+    except RmPowerError:
+        check("extended: nonzero mask word rejected", True)
+    check("extended: no writes on mask violation", rm.writes == [])
+
+
+def test_changes_only_fe_request_and_keeps_vbios_maximum() -> None:
+    for layout in (EXTENDED_LAYOUT, LEGACY_LAYOUT):
+        rm = FakeRm(layout, 250_000)
+        support = probe(BOUNDS, 250_000, rm.query)
+        for cap in (150_000, 30_000, 250_000):
+            set_limit(cap, support, rm.query)
+            check(
+                f"{layout.name}: set {cap} mW",
+                _u32(rm.control, layout.request_at) == cap,
+            )
+        writes = len(rm.writes)
+        for cap in (0, 29_999, 325_001, 350_000, 0xFFFFFFFF):
+            try:
+                set_limit(cap, support, rm.query)
+                check(f"{layout.name}: out-of-range {cap} rejected", False)
+            except RmPowerError:
+                check(f"{layout.name}: out-of-range {cap} rejected", True)
+        check(
+            f"{layout.name}: no writes for out-of-range caps",
+            len(rm.writes) == writes,
+        )
+
+
+def test_restores_previous_below_minimum_request_after_set_or_readback_failure() -> (
+    None
+):
+    for layout in (EXTENDED_LAYOUT, LEGACY_LAYOUT):
+        for fail_set in (False, True):
+            rm = FakeRm(layout, 100_000)
+            original = bytes(rm.control)
+            rm.fail_first_write = fail_set
+            rm.fail_readback = not fail_set
+            support = probe(BOUNDS, 100_000, rm.query)
+            try:
+                set_limit(150_000, support, rm.query)
+                check(f"{layout.name}: failure reported", False)
+            except RmPowerError:
+                check(f"{layout.name}: failure reported", True)
+            check(f"{layout.name}: restore issued", len(rm.writes) == 2)
+            check(
+                f"{layout.name}: previous request restored",
+                bytes(rm.control) == original,
+            )
+
+
+def test_reports_restore_failure_and_rejects_wrong_client_before_writing() -> None:
+    for layout in (EXTENDED_LAYOUT, LEGACY_LAYOUT):
+        rm = FakeRm(layout, 100_000)
+        rm.fail_first_write = True
+        rm.fail_restore = True
+        support = probe(BOUNDS, 100_000, rm.query)
+        try:
+            set_limit(150_000, support, rm.query)
+            check(f"{layout.name}: restore failure reported", False)
+        except RmPowerError as exc:
+            check(
+                f"{layout.name}: restore failure reported",
+                "restoration also failed" in str(exc),
+            )
+        rm = FakeRm(layout, 250_000)
+        rm.control[layout.client_at] = 0xF8
+        try:
+            set_limit(150_000, support, rm.query)
+            check(f"{layout.name}: wrong client rejected", False)
+        except RmPowerError:
+            check(f"{layout.name}: wrong client rejected", True)
+        check(f"{layout.name}: no writes for wrong client", rm.writes == [])
+
+
+# ── PCI identity → RM instance resolution ────────────────────────────────────
+
+
+def test_resolves_pci_identity_when_minor_and_rm_orders_differ() -> None:
+    # This host has Ada at minor 5/RM 4 and the 5090 at minor 4/RM 5.
+    # IDs are opaque and enumeration order must not select the device.
+    pci = PciLocation(domain=0, bus=0x0D, dev=0, func=0)
+    instances = resolve_gpu_instance(pci, lambda cmd, data: _fake_root(cmd, data))
+    check("resolves by PCI identity", instances == (5, 2))
+
+
+def _fake_root(cmd: int, data: bytearray) -> None:
+    if cmd == _CTRL_GPU_GET_ATTACHED_IDS:
+        data[0:4] = (0x2E00).to_bytes(4, "little")
+        data[4:8] = (0x0D00).to_bytes(4, "little")
+    elif cmd == _CTRL_GPU_GET_PCI_INFO:
+        gpu_id = _u32(data, 0)
+        bus = 0x2E if gpu_id == 0x2E00 else 0x0D
+        data[8:10] = bus.to_bytes(2, "little")
+    elif cmd == _CTRL_GPU_GET_ID_INFO_V2:
+        if _u32(data, 0) != 0x0D00:
+            raise AssertionError("unexpected gpu id in ID_INFO_V2")
+        data[8:12] = (5).to_bytes(4, "little")
+        data[12:16] = (2).to_bytes(4, "little")
+    else:
+        raise AssertionError(f"unexpected command {cmd:#x}")
+
+
+def test_does_not_fall_back_to_another_gpu_when_pci_is_missing() -> None:
+    pci = PciLocation(domain=1, bus=0x0D, dev=0, func=0)
+
+    def query(cmd: int, data: bytearray) -> None:
+        if cmd == _CTRL_GPU_GET_ATTACHED_IDS:
+            data[0:4] = (0x0D00).to_bytes(4, "little")
+        elif cmd == _CTRL_GPU_GET_PCI_INFO:
+            data[8:10] = (0x0D).to_bytes(2, "little")
+        else:
+            raise AssertionError("must not allocate a GPU from another PCI domain")
+
+    try:
+        resolve_gpu_instance(pci, query)
+        check("foreign PCI domain rejected", False)
+    except RmPowerError:
+        check("foreign PCI domain rejected", True)
+
+
+def test_rejects_nonzero_pci_function() -> None:
+    pci = PciLocation(domain=0, bus=0x0D, dev=0, func=1)
+    try:
+        resolve_gpu_instance(pci, lambda cmd, data: None)
+        check("nonzero function rejected", False)
+    except RmPowerError:
+        check("nonzero function rejected", True)
+
+
+def test_propagates_rm_query_failure() -> None:
+    pci = PciLocation(domain=0, bus=0x0D, dev=0, func=0)
+    try:
+        resolve_gpu_instance(
+            pci, lambda cmd, data: (_ for _ in ()).throw(RmPowerError("RM unavailable"))
+        )
+        check("RM query failure propagated", False)
+    except RmPowerError as exc:
+        check("RM query failure propagated", "RM unavailable" in str(exc))
+
+
+def main() -> int:
+    tests = [
+        test_detects_both_layouts_with_gets_without_a_driver_version,
+        test_unknown_layout_and_nvml_mismatches_never_write,
+        test_rejects_unrecognized_headers_masks_and_client_values,
+        test_changes_only_fe_request_and_keeps_vbios_maximum,
+        test_restores_previous_below_minimum_request_after_set_or_readback_failure,
+        test_reports_restore_failure_and_rejects_wrong_client_before_writing,
+        test_resolves_pci_identity_when_minor_and_rm_orders_differ,
+        test_does_not_fall_back_to_another_gpu_when_pci_is_missing,
+        test_rejects_nonzero_pci_function,
+        test_propagates_rm_query_failure,
+    ]
+    for t in tests:
+        print(f"== {t.__name__} ==")
+        t()
+    print(f"\n{PASS} passed, {FAIL} failed")
+    return 1 if FAIL else 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

tests/test_security.py

@@ -0,0 +1,263 @@
+"""Security regression tests for nvcurve.
+
+Standalone (no pytest required):
+
+    python tests/test_security.py
+
+Also works under pytest if available. Covers the security-critical logic:
+SPA path containment, snapshot restore containment, login lockout client-IP
+derivation, TLS scheme detection, daemon socket hardening, and the
+server-enforced safety cap.
+"""
+
+import asyncio
+import builtins
+import io
+import os
+import sys
+import tempfile
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
+
+from nvcurve import (
+    daemon,  # noqa: E402
+    server,  # noqa: E402
+)
+from nvcurve.cli import _discover_server_url  # noqa: E402
+from nvcurve.config import (  # noqa: E402
+    Config,
+    normalize_trusted_proxies,
+    tls_enabled,
+)
+from nvcurve.hal.snapshot import restore as snapshot_restore  # noqa: E402
+
+PASS = 0
+FAIL = 0
+
+
+def check(name: str, cond: bool) -> None:
+    global PASS, FAIL
+    if cond:
+        PASS += 1
+        print(f"  PASS  {name}")
+    else:
+        FAIL += 1
+        print(f"  FAIL  {name}")
+
+
+def _encoded_traversal(target: str = "/etc/hostname") -> str:
+    """Build an encoded '..'-based traversal path deep enough to escape any dist dir."""
+    dist = os.path.abspath(server._dist_dir)
+    depth = len(dist.rstrip("/").split("/"))
+    enc = lambda s: s.replace("/", "%2f")  # noqa: E731
+    return "/" + enc("../*" + str(depth + 2) + target)
+
+
+def test_spa_path_containment() -> None:
+    """The SPA catch-all must not serve files outside the dist directory."""
+    from fastapi.testclient import TestClient
+
+    client = TestClient(server.app)
+    r = client.get(_encoded_traversal())
+    check("SPA traversal -> 404", r.status_code == 404)
+    r = client.get(_encoded_traversal("/etc/passwd"))
+    check("SPA traversal /etc/passwd -> 404", r.status_code == 404)
+    # Normal static files must still be served.
+    r = client.get("/index.html")
+    check("SPA /index.html -> 200", r.status_code == 200)
+    r = client.get("/api/nonexistent")
+    check("unknown /api/ path -> 404", r.status_code == 404)
+
+
+def test_snapshot_restore_containment() -> None:
+    """Snapshot restore must only read files inside the snapshot dir."""
+    tmp = tempfile.mkdtemp()
+    snap_dir = os.path.join(tmp, "snaps")
+    os.makedirs(snap_dir)
+    outside = os.path.join(tmp, "evil.bin")
+    with open(outside, "wb") as f:
+        f.write(b"\x00" * 9248)
+
+    check(
+        "restore(outside file) rejected",
+        snapshot_restore(None, snap_dir, outside) is False,
+    )
+    check(
+        "restore(nonexistent) rejected",
+        snapshot_restore(None, snap_dir, "/etc/hostname") is False,
+    )
+    link = os.path.join(snap_dir, "link.bin")
+    os.symlink(outside, link)
+    check(
+        "restore(symlink escape) rejected",
+        snapshot_restore(None, snap_dir, link) is False,
+    )
+
+
+def test_safety_cap_not_client_overridable() -> None:
+    """The API must not accept a per-request safety cap override."""
+    check(
+        "WriteRequest has no max_delta_khz field",
+        "max_delta_khz" not in server.WriteRequest.model_fields,
+    )
+    check(
+        "GlobalOffsetRequest has no max_delta_khz field",
+        "max_delta_khz" not in server.GlobalOffsetRequest.model_fields,
+    )
+
+
+def test_client_ip_derivation() -> None:
+    """X-Forwarded-For is only honoured for configured trusted proxies."""
+
+    class FakeReq:
+        def __init__(self, peer: str, headers: dict):
+            self.client = type("C", (), {"host": peer})()
+            self.headers = headers
+
+    check(
+        "trusted proxy -> XFF used",
+        server._client_ip(
+            FakeReq("127.0.0.1", {"x-forwarded-for": "9.9.9.9"}), ["127.0.0.1"]
+        )
+        == "9.9.9.9",
+    )
+    check(
+        "untrusted peer -> XFF ignored",
+        server._client_ip(
+            FakeReq("8.8.8.8", {"x-forwarded-for": "9.9.9.9"}), ["127.0.0.1"]
+        )
+        == "8.8.8.8",
+    )
+    check(
+        "rightmost untrusted hop",
+        server._client_ip(
+            FakeReq("127.0.0.1", {"x-forwarded-for": "127.0.0.1, 9.9.9.9"}),
+            ["127.0.0.1"],
+        )
+        == "9.9.9.9",
+    )
+    check(
+        "no XFF -> peer",
+        server._client_ip(FakeReq("127.0.0.1", {}), ["127.0.0.1"]) == "127.0.0.1",
+    )
+    check(
+        "all-trusted chain -> peer",
+        server._client_ip(
+            FakeReq("127.0.0.1", {"x-forwarded-for": "10.0.0.1, 10.0.0.2"}),
+            ["127.0.0.1", "10.0.0.1", "10.0.0.2"],
+        )
+        == "127.0.0.1",
+    )
+
+
+def test_trusted_proxies_normalization() -> None:
+    """String values must be normalized to lists (no substring matching)."""
+    check("list passthrough", normalize_trusted_proxies(["1.2.3.4"]) == ["1.2.3.4"])
+    check(
+        "comma string split",
+        normalize_trusted_proxies("1.2.3.4, 5.6.7.8") == ["1.2.3.4", "5.6.7.8"],
+    )
+    check("None -> []", normalize_trusted_proxies(None) == [])
+    check("junk -> []", normalize_trusted_proxies(42) == [])
+    # The original bug: substring membership. After normalization, "127.0.0.1"
+    # must NOT be trusted when only "127.0.0.10" is listed.
+    trusted = normalize_trusted_proxies(["127.0.0.10"])
+    check("no substring trust", "127.0.0.1" not in trusted)
+
+
+def test_tls_scheme_detection() -> None:
+    """_discover_server_url must pick https when TLS is configured."""
+    from nvcurve import cli as cli_mod
+
+    # Hermetic: hide any live server's runtime info file and any existing
+    # persistent config so the defaults level of the priority chain is
+    # exercised.
+    real_info_file = cli_mod._SERVER_INFO_FILE
+    real_persistent_cfg = cli_mod._PERSISTENT_CONFIG_FILE
+    hidden = tempfile.mkdtemp()
+    cli_mod._SERVER_INFO_FILE = os.path.join(hidden, "nvcurve.json")
+    cli_mod._PERSISTENT_CONFIG_FILE = os.path.join(hidden, "config.json")
+    try:
+        cfg = Config(
+            host="10.0.0.5", port=9000, ssl_certfile="/x/c.pem", ssl_keyfile="/x/k.pem"
+        )
+        check("tls_enabled true", tls_enabled(cfg) is True)
+        check("https url", _discover_server_url(cfg) == "https://10.0.0.5:9000")
+        cfg2 = Config(host="10.0.0.5", port=9000)
+        check("http url", _discover_server_url(cfg2) == "http://10.0.0.5:9000")
+    finally:
+        cli_mod._SERVER_INFO_FILE = real_info_file
+        cli_mod._PERSISTENT_CONFIG_FILE = real_persistent_cfg
+
+
+def test_daemon_ignores_caller_host_port() -> None:
+    """serve_start must bind the configured host/port, never the caller's."""
+    daemon._cfg = Config(host="10.1.1.1", port=9999)
+    captured: dict = {}
+
+    class FakePopen:
+        def __init__(self, cmd, **kw):
+            captured["cmd"] = cmd
+            self.pid = 4242
+
+        def poll(self):
+            return 0
+
+        def terminate(self):
+            pass
+
+        def wait(self, *a):
+            return 0
+
+    real_open = builtins.open
+
+    def fake_open(path, *a, **kw):
+        if str(path).endswith("nvcurve-server.log"):
+            return io.StringIO()
+        return real_open(path, *a, **kw)
+
+    orig_popen = daemon.subprocess.Popen
+    daemon.subprocess.Popen = FakePopen
+    builtins.open = fake_open
+    try:
+        loop = asyncio.new_event_loop()
+        resp = loop.run_until_complete(
+            # "0.0.0.0" is a test payload proving the daemon ignores caller
+            # host/port — no socket is bound here.
+            daemon._dispatch({"cmd": "serve_start", "host": "0.0.0.0", "port": 12345})  # noqa: S104
+        )
+    finally:
+        builtins.open = real_open
+        daemon.subprocess.Popen = orig_popen
+
+    cmd = " ".join(captured.get("cmd", []))
+    check("config host/port used", "10.1.1.1" in cmd and "9999" in cmd)
+    check("caller host/port ignored", "0.0.0.0" not in cmd and "12345" not in cmd)  # noqa: S104
+    check(
+        "response reports configured values",
+        resp.get("ok") is True
+        and resp.get("host") == "10.1.1.1"
+        and resp.get("port") == 9999,
+    )
+    check("response includes tls flag", "tls" in resp)
+
+
+def main() -> int:
+    tests = [
+        test_spa_path_containment,
+        test_snapshot_restore_containment,
+        test_safety_cap_not_client_overridable,
+        test_client_ip_derivation,
+        test_trusted_proxies_normalization,
+        test_tls_scheme_detection,
+        test_daemon_ignores_caller_host_port,
+    ]
+    for t in tests:
+        print(f"== {t.__name__} ==")
+        t()
+    print(f"\n{PASS} passed, {FAIL} failed")
+    return 1 if FAIL else 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

uv.lock

@@ -154,6 +154,22 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/04/4b/29cac41a4d98d144bf5f6d33995617b185d14b22401f75ca86f384e87ff1/h11-0.16.0-py3-none-any.whl", hash = "sha256:63cf8bbe7522de3bf65932fda1d9c2772064ffb3dae62d55932da54b31cb6c86", size = 37515, upload-time = "2025-04-24T03:35:24.344Z" },
 ]
 
+[[package]]
+name = "hatchling"
+version = "1.32.0"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "packaging" },
+    { name = "pathspec" },
+    { name = "pluggy" },
+    { name = "tomlkit" },
+    { name = "trove-classifiers" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/69/08/33331757185504aae48b8d9bd78cec03a76e3aecfb52e549d05a2347c0dd/hatchling-1.32.0.tar.gz", hash = "sha256:0bdbde4a52b06c37e3eca395f85a762bf0ef06fe374fd8ae429dc6be10230f5f", size = 57783, upload-time = "2026-08-11T05:03:44.114Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/a9/84/1798b6d85ecde0e31546004efd25c5de1b1f49250644a60cce460e12593a/hatchling-1.32.0-py3-none-any.whl", hash = "sha256:0e17c9c3b9aa7c625acc8d0f5b622f107d5049af9ecf5ada4de1aada5be7cdbc", size = 78435, upload-time = "2026-08-11T05:03:42.644Z" },
+]
+
 [[package]]
 name = "httpcore"
 version = "1.0.9"
@@ -233,6 +249,11 @@ dependencies = [
     { name = "uvicorn", extra = ["standard"] },
 ]
 
+[package.dev-dependencies]
+dev = [
+    { name = "hatchling" },
+]
+
 [package.metadata]
 requires-dist = [
     { name = "bcrypt", specifier = ">=4.0" },
@@ -243,6 +264,9 @@ requires-dist = [
     { name = "uvicorn", extras = ["standard"], specifier = ">=0.30" },
 ]
 
+[package.metadata.requires-dev]
+dev = [{ name = "hatchling" }]
+
 [[package]]
 name = "nvidia-ml-py"
 version = "13.590.48"
@@ -252,6 +276,33 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/fd/72/fb2af0d259a651affdce65fd6a495f0e07a685a0136baf585c5065204ee7/nvidia_ml_py-13.590.48-py3-none-any.whl", hash = "sha256:fd43d30ee9cd0b7940f5f9f9220b68d42722975e3992b6c21d14144c48760e43", size = 50680, upload-time = "2026-01-22T01:14:55.281Z" },
 ]
 
+[[package]]
+name = "packaging"
+version = "26.3"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/7d/fa/3944b40b07da9ce895c0e6303a5ab7d53da063554f534556b134a54d6093/packaging-26.3.tar.gz", hash = "sha256:94edc256424af38762eb31306eed28beb9f0efc50a8837492c9d6fd6004aed79", size = 313412, upload-time = "2026-08-04T18:15:28.737Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/63/34/ba1c580383c9eada3711951fef0795c80b829a078d72188184bcab9dd527/packaging-26.3-py3-none-any.whl", hash = "sha256:d7193f7c8e4e93f444fde0262bf90af30e16fa0ad0ad44cb553c87339b23cd1c", size = 129956, upload-time = "2026-08-04T18:15:27.159Z" },
+]
+
+[[package]]
+name = "pathspec"
+version = "1.1.1"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/5a/82/42f767fc1c1143d6fd36efb827202a2d997a375e160a71eb2888a925aac1/pathspec-1.1.1.tar.gz", hash = "sha256:17db5ecd524104a120e173814c90367a96a98d07c45b2e10c2f3919fff91bf5a", size = 135180, upload-time = "2026-04-27T01:46:08.907Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/f1/d9/7fb5aa316bc299258e68c73ba3bddbc499654a07f151cba08f6153988714/pathspec-1.1.1-py3-none-any.whl", hash = "sha256:a00ce642f577bf7f473932318056212bc4f8bfdf53128c78bbd5af0b9b20b189", size = 57328, upload-time = "2026-04-27T01:46:07.06Z" },
+]
+
+[[package]]
+name = "pluggy"
+version = "1.6.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/f9/e2/3e91f31a7d2b083fe6ef3fa267035b518369d9511ffab804f839851d2779/pluggy-1.6.0.tar.gz", hash = "sha256:7dcc130b76258d33b90f61b658791dede3486c3e6bfb003ee5c9bfb396dd22f3", size = 69412, upload-time = "2025-05-15T12:30:07.975Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/54/20/4d324d65cc6d9205fabedc306948156824eb9f0ee1633355a8f7ec5c66bf/pluggy-1.6.0-py3-none-any.whl", hash = "sha256:e920276dd6813095e9377c0bc5566d94c932c33b27a3e3945d8389c374dd4746", size = 20538, upload-time = "2025-05-15T12:30:06.134Z" },
+]
+
 [[package]]
 name = "pydantic"
 version = "2.12.5"
@@ -406,6 +457,24 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/81/0d/13d1d239a25cbfb19e740db83143e95c772a1fe10202dda4b76792b114dd/starlette-0.52.1-py3-none-any.whl", hash = "sha256:0029d43eb3d273bc4f83a08720b4912ea4b071087a3b48db01b7c839f7954d74", size = 74272, upload-time = "2026-01-18T13:34:09.188Z" },
 ]
 
+[[package]]
+name = "tomlkit"
+version = "0.15.1"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/94/96/e07752635b98536177fa1f37671c8f3cdde2e724c6bcf6034b2cfb571565/tomlkit-0.15.1.tar.gz", hash = "sha256:e25bbf38843005246210a12982776f27f99cb9be67160e14434d0c0d21ee1e97", size = 180129, upload-time = "2026-07-17T01:48:04.562Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/13/bc/8c13eb66537dce1d2bd3a57132902f38d0e7f5bb46fa9f4daed9fe9d76ee/tomlkit-0.15.1-py3-none-any.whl", hash = "sha256:177a05aece5a8ca5266fd3c448abb47b8d352f09d477d3ca8332db4d89b24304", size = 49449, upload-time = "2026-07-17T01:48:05.728Z" },
+]
+
+[[package]]
+name = "trove-classifiers"
+version = "2026.6.1.19"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/c2/e3/7ca82ee24c82d344584abd5b8637b3bd056f2900226e8d82fc22f1184b92/trove_classifiers-2026.6.1.19.tar.gz", hash = "sha256:c5132b4b61a829d11cfbd2d72e97f20a45ed6edb95e45c5efdeb5e00836b2745", size = 17059, upload-time = "2026-06-01T19:41:34.649Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/7c/a4/81502f486f01db95bc8320646a8a12511f5e556cb63d5e224d91816605c4/trove_classifiers-2026.6.1.19-py3-none-any.whl", hash = "sha256:ab4c4ec93cc4a4e7815fa759906e05e6bb3f2fbd92ea0f897288c6a43efd15b3", size = 14211, upload-time = "2026-06-01T19:41:33.434Z" },
+]
+
 [[package]]
 name = "typing-extensions"
 version = "4.15.0"