Persist one browser user agent for Axios and WebSockets

app/api/debug/route.ts

@@ -3,7 +3,7 @@ import { getClients, resetClients } from '@/lib/clients';
 import { getTradableFirms } from '@/lib/firm-catalog';
 import { getAccountConfig } from '@/lib/account-type-resolver';
 import { combineCmeSessions, computeDayPlan, resolveEffectiveConfig, currentTradeDateCT } from '@/lib/trading-logic';
-import axios from 'axios';
+import axios from '@/lib/http-client';
 
 /**
  * Per-account snapshot of everything computeDayPlan sees, plus the book-balance

app/api/firms/[id]/debug-contracts/route.ts

@@ -1,6 +1,6 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { getClients } from '@/lib/clients';
-import axios from 'axios';
+import axios from '@/lib/http-client';
 
 export async function GET(
     req: NextRequest,

app/api/settings/route.ts

@@ -1,6 +1,7 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { getSetting, setSetting } from '@/lib/db';
 import { scheduleBackupPush } from '@/lib/backup-sync';
+import { getRequestUserAgent } from '@/lib/request-user-agent';
 
 const VALID_KEYS = ['max_concurrent_accounts', 'tick_interval_seconds', 'master_dashboard_url', 'instance_name', 'trading_hours', 'twocaptcha_api_key', 'twocaptcha_proxy', 'master_backup_token', 'proxy_url'] as const;
 type SettingKey = typeof VALID_KEYS[number];
@@ -13,6 +14,8 @@ export async function GET() {
     // Read-only on purpose (not in VALID_KEYS): the master issues this uuid,
     // and editing it by hand would detach the instance from its person.
     result.instance_id = getSetting('instance_id');
+    // Generated once per instance. Callers cannot rotate an active identity.
+    result.user_agent = getRequestUserAgent();
     result.backup_last_push_at = getSetting('backup_last_push_at');
     result.backup_last_error = getSetting('backup_last_error');
     return NextResponse.json(result);

app/settings/page.tsx

@@ -47,6 +47,7 @@ interface AppSettings {
     trading_hours: string | null;
     master_backup_token: string | null;
     proxy_url: string | null;
+    user_agent: string | null;
     backup_last_push_at: string | null;
     backup_last_error: string | null;
 }
@@ -77,6 +78,7 @@ export default function SettingsPage() {
     const [saved, setSaved] = useState(false);
     const [backupToken, setBackupToken] = useState<string>('');
     const [proxyUrl, setProxyUrl] = useState<string>('');
+    const [userAgent, setUserAgent] = useState<string>('');
     const [backupStatus, setBackupStatus] = useState<{ at: string | null; error: string | null }>({ at: null, error: null });
     const [restoreList, setRestoreList] = useState<BackupMeta[] | null>(null);
     const [restoreBusy, setRestoreBusy] = useState(false);
@@ -130,6 +132,7 @@ export default function SettingsPage() {
                 if (s.proxy_url != null) {
                     setProxyUrl(s.proxy_url);
                 }
+                setUserAgent(s.user_agent ?? '');
                 setBackupStatus({ at: s.backup_last_push_at, error: s.backup_last_error || null });
             });
 
@@ -440,6 +443,16 @@ export default function SettingsPage() {
                             className="w-72 rounded-lg border border-slate-200 bg-slate-50 px-3 py-1.5 text-sm font-mono text-slate-800 focus:outline-none focus:ring-2 focus:ring-blue-500"
                         />
                     </div>
+                    <div className="border-t border-slate-100 px-4 py-3">
+                        <p className="text-sm font-medium text-slate-800">User agent</p>
+                        <p className="text-xs text-slate-400 mt-0.5">
+                            Chrome, Firefox, or Edge is randomly selected on first load and saved.
+                            All server Axios requests and WebSocket connections reuse it, including after restarts.
+                        </p>
+                        <p className="mt-2 break-all rounded-lg bg-slate-50 px-3 py-2 text-xs font-mono text-slate-700">
+                            {userAgent || 'Loading…'}
+                        </p>
+                    </div>
                 </div>
 
                 {/* ── Instruments ── */}