add cli flags to spoof user agent

src/main/cli.ts

@@ -0,0 +1,100 @@
+/*
+ * Vesktop, a desktop app aiming to give you a snappier Discord Experience
+ * Copyright (c) 2025 Vendicated and Vesktop contributors
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+import { app } from "electron";
+import { stripIndent } from "shared/utils/text";
+import { parseArgs, ParseArgsOptionDescriptor } from "util";
+
+const options = {
+    "start-minimized": {
+        default: false,
+        type: "boolean",
+        short: "m",
+        description: "Start the application minimized to the system tray"
+    },
+    version: {
+        type: "boolean",
+        short: "v",
+        description: "Print the application version and exit"
+    },
+    help: {
+        type: "boolean",
+        short: "h",
+        description: "Print help information and exit"
+    },
+    "user-agent": {
+        type: "string",
+        argumentName: "ua",
+        description: "Set a custom User-Agent. May trigger anti-spam or break voice chat"
+    },
+    "user-agent-os": {
+        type: "string",
+        description: "Set User-Agent to a specific operating system. May trigger anti-spam or break voice chat",
+        options: ["windows", "linux", "darwin"]
+    }
+} satisfies Record<
+    string,
+    ParseArgsOptionDescriptor & { description: string; options?: string[]; argumentName?: string }
+>;
+
+export const CommandLine = parseArgs({
+    options,
+    strict: true,
+    allowPositionals: true
+});
+
+export function checkCommandLineForHelpOrVersion() {
+    const { help, version } = CommandLine.values;
+
+    if (version) {
+        console.error(`Vesktop v${app.getVersion()}`);
+        app.exit(0);
+    }
+
+    if (help) {
+        const base = stripIndent`
+            Vesktop v${app.getVersion()}
+
+            Usage: ${process.execPath} [options] [url]
+
+            Options:
+        `;
+
+        const optionLines = Object.entries(options)
+            .sort(([a], [b]) => a.localeCompare(b))
+            .map(([name, opt]) => {
+                const flags = [
+                    "short" in opt && `-${opt.short}`,
+                    `--${name}`,
+                    opt.type !== "boolean" &&
+                        ("options" in opt ? `<${opt.options.join(" | ")}>` : `<${opt.argumentName ?? opt.type}>`)
+                ]
+                    .filter(Boolean)
+                    .join(" ");
+
+                return [flags, opt.description];
+            });
+
+        const padding = optionLines.reduce((max, [flags]) => Math.max(max, flags.length), 0) + 4;
+
+        const optionsHelp = optionLines
+            .map(([flags, description]) => `  ${flags.padEnd(padding, " ")}${description}`)
+            .join("\n");
+
+        console.error(base + "\n" + optionsHelp);
+        app.exit(0);
+    }
+
+    for (const [name, def] of Object.entries(options)) {
+        const value = CommandLine.values[name];
+        if (!value) continue;
+
+        if ("options" in def && !def.options?.includes(value)) {
+            console.error(`Invalid value for --${name}: ${value}\nExpected one of: ${def.options.join(", ")}`);
+            app.exit(1);
+        }
+    }
+}

src/main/constants.ts

@@ -8,6 +8,8 @@ import { app } from "electron";
 import { existsSync, mkdirSync } from "fs";
 import { dirname, join } from "path";
 
+import { CommandLine } from "./cli";
+
 const vesktopDir = dirname(process.execPath);
 
 export const PORTABLE =
@@ -45,7 +47,10 @@ const BrowserUserAgents = {
     windows: `Mozilla/5.0 (Windows NT 10.0; Win64; x64) ${VersionString}`
 };
 
-export const BrowserUserAgent = BrowserUserAgents[process.platform] || BrowserUserAgents.windows;
+export const BrowserUserAgent =
+    CommandLine.values["user-agent"] ||
+    BrowserUserAgents[CommandLine.values["user-agent-os"] || process.platform] ||
+    BrowserUserAgents.windows;
 
 export const enum MessageBoxChoice {
     Default,

src/main/index.ts

@@ -10,6 +10,7 @@ import "./userAssets";
 import { app, BrowserWindow, nativeTheme } from "electron";
 import { autoUpdater } from "electron-updater";
 
+import { checkCommandLineForHelpOrVersion } from "./cli";
 import { DATA_DIR } from "./constants";
 import { createFirstLaunchTour } from "./firstLaunch";
 import { createWindows, mainWin } from "./mainWindow";
@@ -19,6 +20,8 @@ import { Settings, State } from "./settings";
 import { setAsDefaultProtocolClient } from "./utils/setAsDefaultProtocolClient";
 import { isDeckGameMode } from "./utils/steamOS";
 
+checkCommandLineForHelpOrVersion();
+
 if (!IS_DEV) {
     autoUpdater.checkForUpdatesAndNotify();
 }

src/main/mainWindow.ts

@@ -22,6 +22,7 @@ import type { SettingsStore } from "shared/utils/SettingsStore";
 
 import { createAboutWindow } from "./about";
 import { initArRPC } from "./arrpc";
+import { CommandLine } from "./cli";
 import { BrowserUserAgent, DEFAULT_HEIGHT, DEFAULT_WIDTH, MIN_HEIGHT, MIN_WIDTH } from "./constants";
 import { AppEvents } from "./events";
 import { darwinURL } from "./index";
@@ -428,7 +429,7 @@ function retryUrl(url: string, description: string) {
 }
 
 export async function createWindows() {
-    const startMinimized = process.argv.includes("--start-minimized");
+    const startMinimized = CommandLine.values["start-minimized"];
 
     let splash: BrowserWindow | undefined;
     if (Settings.store.enableSplashScreen !== false) {