Ingest live 3proxy traffic from access logs

README.md

@@ -9,6 +9,7 @@ The project now includes both the UI and the first backend/runtime slice:
 - Express-based control plane API
 - generated `3proxy.cfg` from persisted panel state
 - runtime manager for start/restart/reload
+- access-log-backed traffic ingestion from a real 3proxy process
 - Docker image that builds the panel and compiles 3proxy in-container
 - panel views for dashboard, users, and system
 - edge-case-focused frontend and backend tests
@@ -35,6 +36,7 @@ For Docker runs these values come from `compose.yaml`:
 - `PANEL_SESSION_TTL_HOURS` with a default of `24`
 
 The panel stores the issued session token in `sessionStorage`, so a browser refresh keeps the operator signed in until the token expires.
+Once the API is available, dashboard/user traffic values are refreshed from live 3proxy access logs instead of the seeded fallback snapshot.
 
 ## Docker run
 

docs/PLAN.md

@@ -4,7 +4,7 @@ Updated: 2026-04-02
 
 ## Active
 
-1. Harden the backend/runtime layer, keep replacing fallback UI behavior with runtime-backed signals, and prepare the next slice of real traffic/counter ingestion.
+1. Keep replacing remaining seeded fallback signals with runtime-backed 3proxy data and extend the Docker-verified ingestion path beyond access-log-derived usage.
 
 ## Next
 
@@ -36,3 +36,5 @@ Updated: 2026-04-02
 20. Made `npm run dev` start both the Vite client and Express backend, added a Vite API proxy for local development, and restored `system` as the default panel theme so the login screen follows OS appearance.
 21. Re-separated the Settings tab into distinct panel-settings and services cards so panel preferences no longer appear inside the Services section.
 22. Restored editable proxy endpoint in panel settings so copied proxy URLs and displayed user endpoints can be corrected from the UI.
+23. Replaced seeded dashboard/user usage with live 3proxy access-log ingestion, derived user traffic/status from runtime logs, and added frontend polling so the panel refreshes runtime state automatically.
+24. Verified the new runtime-backed snapshot flow in Docker by sending real traffic through the bundled 3proxy services and observing live byte counters in `/api/state`.

docs/PROJECT_INDEX.md

@@ -23,7 +23,7 @@ Updated: 2026-04-02
 ## Frontend
 
 - `src/main.tsx`: application bootstrap
-- `src/App.tsx`: authenticated panel shell with API-backed login, `sessionStorage` token persistence, localized labels, early theme application, and protected panel mutations
+- `src/App.tsx`: authenticated panel shell with API-backed login, `sessionStorage` token persistence, localized labels, early theme application, protected panel mutations, and periodic runtime snapshot refresh
 - `src/SystemTab.tsx`: Settings tab with separate panel-settings and services cards, editable proxy endpoint, unified service type editing, remove confirmation, and generated config preview
 - `src/App.test.tsx`: login-gate, preferences persistence, modal interaction, pause/resume, delete-confirm, and settings-save UI tests
 - `src/app.css`: full panel styling
@@ -44,6 +44,9 @@ Updated: 2026-04-02
 - `server/lib/auth.ts`: expiring token issuance and bearer-token verification for the panel
 - `server/lib/config.ts`: 3proxy config renderer, validation, and dashboard derivation for SOCKS/HTTP managed services
 - `server/lib/config.test.ts`: config-generation regression tests
+- `server/lib/snapshot.ts`: runtime-backed dashboard snapshot assembly that combines stored panel state with parsed 3proxy traffic observations
+- `server/lib/traffic.ts`: 3proxy access-log reader that derives current user usage, recent activity, daily totals, and lightweight live-connection estimates
+- `server/lib/traffic.test.ts`: parser and empty-runtime regression tests for log-derived traffic metrics
 - `server/lib/runtime.ts`: managed 3proxy process controller
 - `server/lib/store.ts`: JSON-backed persistent state store with legacy admin-service migration
 

server/app.ts

@@ -11,10 +11,10 @@ import { validateCreateUserInput, validateSystemInput } from '../src/shared/vali
 import {
   buildRuntimePaths,
   createUserRecord,
-  deriveDashboardSnapshot,
   render3proxyConfig,
   type RuntimePaths,
 } from './lib/config';
+import { getDashboardSnapshot } from './lib/snapshot';
 import { AuthService } from './lib/auth';
 import type { RuntimeController } from './lib/runtime';
 import { StateStore } from './lib/store';
@@ -81,7 +81,7 @@ export function createApp({ store, runtime, runtimeRootDir, auth }: AppServices)
 
   app.get('/api/state', async (_request, response, next) => {
     try {
-      const payload = await getSnapshot(store, runtime, runtimePaths);
+      const payload = await getDashboardSnapshot(store, runtime, runtimePaths);
       response.json(payload);
     } catch (error) {
       next(error);
@@ -106,7 +106,7 @@ export function createApp({ store, runtime, runtimeRootDir, auth }: AppServices)
       }
 
       await writeConfigAndState(store, state, runtimePaths);
-      response.json(await getSnapshot(store, runtime, runtimePaths));
+      response.json(await getDashboardSnapshot(store, runtime, runtimePaths));
     } catch (error) {
       next(error);
     }
@@ -120,7 +120,7 @@ export function createApp({ store, runtime, runtimeRootDir, auth }: AppServices)
       state.userRecords.push(record);
       state.service.lastEvent = `User ${record.username} created from panel`;
       await persistRuntimeMutation(store, runtime, state, runtimePaths);
-      response.status(201).json(await getSnapshot(store, runtime, runtimePaths));
+      response.status(201).json(await getDashboardSnapshot(store, runtime, runtimePaths));
     } catch (error) {
       next(error);
     }
@@ -147,7 +147,7 @@ export function createApp({ store, runtime, runtimeRootDir, auth }: AppServices)
           ? `System configuration updated from panel and removed ${removedUsers.length} linked users`
           : 'System configuration updated from panel';
       await persistRuntimeMutation(store, runtime, state, runtimePaths);
-      response.json(await getSnapshot(store, runtime, runtimePaths));
+      response.json(await getDashboardSnapshot(store, runtime, runtimePaths));
     } catch (error) {
       next(error);
     }
@@ -169,7 +169,7 @@ export function createApp({ store, runtime, runtimeRootDir, auth }: AppServices)
         : `User ${user.username} resumed from panel`;
 
       await persistRuntimeMutation(store, runtime, state, runtimePaths);
-      response.json(await getSnapshot(store, runtime, runtimePaths));
+      response.json(await getDashboardSnapshot(store, runtime, runtimePaths));
     } catch (error) {
       next(error);
     }
@@ -188,7 +188,7 @@ export function createApp({ store, runtime, runtimeRootDir, auth }: AppServices)
       const [removed] = state.userRecords.splice(index, 1);
       state.service.lastEvent = `User ${removed.username} deleted from panel`;
       await persistRuntimeMutation(store, runtime, state, runtimePaths);
-      response.json(await getSnapshot(store, runtime, runtimePaths));
+      response.json(await getDashboardSnapshot(store, runtime, runtimePaths));
     } catch (error) {
       next(error);
     }
@@ -214,15 +214,6 @@ export function createApp({ store, runtime, runtimeRootDir, auth }: AppServices)
   return app;
 }
 
-async function getSnapshot(
-  store: StateStore,
-  runtime: RuntimeController,
-  runtimePaths: RuntimePaths,
-) {
-  const state = await store.read();
-  const previewConfig = render3proxyConfig(state, runtimePaths);
-  return deriveDashboardSnapshot(state, runtime.getSnapshot(), previewConfig);
-}
 async function persistRuntimeMutation(
   store: StateStore,
   runtime: RuntimeController,

server/lib/config.test.ts

@@ -35,5 +35,6 @@ describe('render3proxyConfig', () => {
     expect(config).not.toContain('night-shift:CL:kettle!23');
     expect(config).not.toContain('allow night-shift,ops-east');
     expect(config).toContain('allow ops-east');
+    expect(config).toContain('countall 1 D 1024 night-shift');
   });
 });

server/lib/config.ts

@@ -4,6 +4,7 @@ import type {
   ControlPlaneState,
   CreateUserInput,
   DashboardSnapshot,
+  DailyTrafficBucket,
   ProxyServiceRecord,
   ProxyUserRecord,
 } from '../../src/shared/contracts';
@@ -19,6 +20,14 @@ export interface RuntimeSnapshot {
   lastError: string | null;
 }
 
+export interface ObservedRuntimeState {
+  totalBytes: number;
+  liveConnections: number;
+  activeUsers: number;
+  daily: DailyTrafficBucket[];
+  userRecords: ProxyUserRecord[];
+}
+
 export interface RuntimePaths {
   rootDir: string;
   configPath: string;
@@ -73,7 +82,7 @@ export function render3proxyConfig(state: ControlPlaneState, paths: RuntimePaths
     lines.push(`users ${activeUsers.map(renderUserCredential).join(' ')}`);
   }
 
-  const quotaUsers = activeUsers.filter((user) => user.quotaBytes !== null);
+  const quotaUsers = state.userRecords.filter((user) => user.quotaBytes !== null);
   if (quotaUsers.length > 0) {
     lines.push(
       `counter ${normalizePath(paths.counterPath)} D ${normalizePath(
@@ -112,13 +121,14 @@ export function render3proxyConfig(state: ControlPlaneState, paths: RuntimePaths
 export function deriveDashboardSnapshot(
   state: ControlPlaneState,
   runtime: RuntimeSnapshot,
+  observed: ObservedRuntimeState,
   previewConfig: string,
 ): DashboardSnapshot {
-  const liveUsers = state.userRecords.filter((user) => !user.paused && user.status === 'live').length;
-  const exceededUsers = state.userRecords.filter(
+  const liveUsers = observed.userRecords.filter((user) => !user.paused && user.status === 'live').length;
+  const exceededUsers = observed.userRecords.filter(
     (user) => user.quotaBytes !== null && user.usedBytes >= user.quotaBytes,
   ).length;
-  const nearQuotaUsers = state.userRecords.filter((user) => {
+  const nearQuotaUsers = observed.userRecords.filter((user) => {
     if (user.paused || user.quotaBytes === null || user.usedBytes >= user.quotaBytes) {
       return false;
     }
@@ -175,17 +185,19 @@ export function deriveDashboardSnapshot(
       lastEvent: state.service.lastEvent,
     },
     traffic: {
-      ...state.traffic,
-      activeUsers: state.userRecords.filter((user) => !user.paused).length,
+      totalBytes: observed.totalBytes,
+      liveConnections: observed.liveConnections,
+      activeUsers: observed.activeUsers,
+      daily: observed.daily,
     },
     users: {
-      total: state.userRecords.length,
+      total: observed.userRecords.length,
       live: liveUsers,
       nearQuota: nearQuotaUsers,
       exceeded: exceededUsers,
     },
     attention,
-    userRecords: state.userRecords,
+    userRecords: observed.userRecords,
     system: {
       ...state.system,
       previewConfig,

server/lib/snapshot.ts

@@ -0,0 +1,64 @@
+import type { ProxyUserRecord } from '../../src/shared/contracts';
+import { deriveDashboardSnapshot, render3proxyConfig, type ObservedRuntimeState, type RuntimePaths, type RuntimeSnapshot } from './config';
+import type { StateStore } from './store';
+import { readObservedTraffic } from './traffic';
+
+export async function getDashboardSnapshot(
+  store: StateStore,
+  runtime: { getSnapshot(): RuntimeSnapshot },
+  runtimePaths: RuntimePaths,
+) {
+  const state = await store.read();
+  const previewConfig = render3proxyConfig(state, runtimePaths);
+  const traffic = await readObservedTraffic(runtimePaths, state.userRecords);
+  const observedUsers = deriveObservedUsers(state.userRecords, traffic.userBytesByName, traffic.recentUsers);
+  const observed: ObservedRuntimeState = {
+    totalBytes: traffic.totalBytes,
+    liveConnections: traffic.liveConnections,
+    activeUsers: traffic.activeUsers,
+    daily: traffic.daily,
+    userRecords: observedUsers,
+  };
+
+  return deriveDashboardSnapshot(state, runtime.getSnapshot(), observed, previewConfig);
+}
+
+function deriveObservedUsers(
+  users: ProxyUserRecord[],
+  userBytesByName: Map<string, number>,
+  recentUsers: Set<string>,
+): ProxyUserRecord[] {
+  return users.map((user) => {
+    const usedBytes = userBytesByName.get(user.username) ?? 0;
+
+    if (user.paused) {
+      return {
+        ...user,
+        usedBytes,
+        status: 'idle',
+      };
+    }
+
+    if (user.quotaBytes !== null && usedBytes >= user.quotaBytes) {
+      return {
+        ...user,
+        usedBytes,
+        status: 'fail',
+      };
+    }
+
+    if (user.quotaBytes !== null && user.quotaBytes > 0 && usedBytes / user.quotaBytes >= 0.8) {
+      return {
+        ...user,
+        usedBytes,
+        status: recentUsers.has(user.username) ? 'live' : 'warn',
+      };
+    }
+
+    return {
+      ...user,
+      usedBytes,
+      status: recentUsers.has(user.username) ? 'live' : 'idle',
+    };
+  });
+}

server/lib/traffic.test.ts

@@ -0,0 +1,104 @@
+import fs from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+import { afterEach, describe, expect, it } from 'vitest';
+import type { ProxyUserRecord } from '../../src/shared/contracts';
+import { readObservedTraffic } from './traffic';
+
+const cleanupDirs: string[] = [];
+
+afterEach(async () => {
+  await Promise.all(cleanupDirs.splice(0).map((dir) => fs.rm(dir, { recursive: true, force: true })));
+});
+
+describe('readObservedTraffic', () => {
+  it('derives current user usage, recent activity, and daily totals from 3proxy access logs', async () => {
+    const dir = await fs.mkdtemp(path.join(os.tmpdir(), '3proxy-traffic-'));
+    cleanupDirs.push(dir);
+
+    const logDir = path.join(dir, 'logs');
+    await fs.mkdir(logDir, { recursive: true });
+    await fs.writeFile(
+      path.join(logDir, '3proxy.log.2026.04.02'),
+      [
+        '260402111500.000 1080 00000 night-shift 172.19.0.1:54402 104.18.27.120:80 100 900 0 GET http://example.com/ HTTP/1.1',
+        '260402115900.000 2080 00000 lab-unlimited 172.19.0.1:53490 8.6.112.0:80 75 842 0 CONNECT example.com:80',
+        '260402115930.000 1080 00000 - 0.0.0.0:1080 0.0.0.0:0 0 0 0 Accepting connections [18/1]',
+      ].join('\n'),
+      'utf8',
+    );
+    await fs.writeFile(
+      path.join(logDir, '3proxy.log.2026.04.01'),
+      '260401230000.000 1080 00000 night-shift 172.19.0.1:50000 104.18.27.120:80 50 150 0 GET http://example.com/ HTTP/1.1\n',
+      'utf8',
+    );
+
+    const users: ProxyUserRecord[] = [
+      {
+        id: 'u-1',
+        username: 'night-shift',
+        password: 'secret',
+        serviceId: 'socks-main',
+        status: 'idle',
+        usedBytes: 0,
+        quotaBytes: 1024,
+      },
+      {
+        id: 'u-2',
+        username: 'lab-unlimited',
+        password: 'secret',
+        serviceId: 'socks-lab',
+        status: 'idle',
+        usedBytes: 0,
+        quotaBytes: null,
+      },
+    ];
+
+    const observed = await readObservedTraffic(
+      {
+        rootDir: dir,
+        configPath: path.join(dir, 'generated', '3proxy.cfg'),
+        counterPath: path.join(dir, 'state', 'counters.3cf'),
+        reportDir: path.join(dir, 'state', 'reports'),
+        logPath: path.join(logDir, '3proxy.log'),
+        pidPath: path.join(dir, '3proxy.pid'),
+      },
+      users,
+      new Date(2026, 3, 2, 12, 0, 0, 0),
+    );
+
+    expect(observed.totalBytes).toBe(1917);
+    expect(observed.liveConnections).toBe(1);
+    expect(observed.activeUsers).toBe(2);
+    expect(observed.userBytesByName.get('night-shift')).toBe(1000);
+    expect(observed.userBytesByName.get('lab-unlimited')).toBe(917);
+    expect(observed.recentUsers.has('night-shift')).toBe(false);
+    expect(observed.recentUsers.has('lab-unlimited')).toBe(true);
+    expect(observed.daily[observed.daily.length - 2].bytes).toBe(200);
+    expect(observed.daily[observed.daily.length - 1].bytes).toBe(1917);
+  });
+
+  it('returns zeroed metrics when no runtime logs exist yet', async () => {
+    const dir = await fs.mkdtemp(path.join(os.tmpdir(), '3proxy-traffic-empty-'));
+    cleanupDirs.push(dir);
+
+    const observed = await readObservedTraffic(
+      {
+        rootDir: dir,
+        configPath: path.join(dir, 'generated', '3proxy.cfg'),
+        counterPath: path.join(dir, 'state', 'counters.3cf'),
+        reportDir: path.join(dir, 'state', 'reports'),
+        logPath: path.join(dir, 'logs', '3proxy.log'),
+        pidPath: path.join(dir, '3proxy.pid'),
+      },
+      [],
+      new Date(2026, 3, 2, 12, 0, 0, 0),
+    );
+
+    expect(observed.totalBytes).toBe(0);
+    expect(observed.liveConnections).toBe(0);
+    expect(observed.activeUsers).toBe(0);
+    expect(observed.daily).toHaveLength(5);
+    expect(observed.daily.every((entry) => entry.bytes === 0 && entry.share === 0)).toBe(true);
+  });
+});

server/lib/traffic.ts

@@ -0,0 +1,184 @@
+import fs from 'node:fs/promises';
+import path from 'node:path';
+import type { DailyTrafficBucket, ProxyUserRecord } from '../../src/shared/contracts';
+import type { RuntimePaths } from './config';
+
+const LOG_FILE_PREFIX = '3proxy.log';
+const RECENT_WINDOW_MS = 15 * 60 * 1000;
+const CONNECTION_WINDOW_MS = 5 * 60 * 1000;
+const HISTORY_DAYS = 5;
+
+export interface ObservedTraffic {
+  totalBytes: number;
+  liveConnections: number;
+  activeUsers: number;
+  daily: DailyTrafficBucket[];
+  userBytesByName: Map<string, number>;
+  recentUsers: Set<string>;
+}
+
+interface ParsedLogRecord {
+  timestamp: Date;
+  username: string;
+  bytes: number;
+}
+
+export async function readObservedTraffic(
+  runtimePaths: RuntimePaths,
+  users: ProxyUserRecord[],
+  now = new Date(),
+): Promise<ObservedTraffic> {
+  const records = await readParsedRecords(runtimePaths.logPath);
+  const currentDayKey = toDayKey(now);
+  const historyStart = startOfDay(now);
+  const history = buildHistoryDays(historyStart, HISTORY_DAYS);
+  const dailyTotals = new Map(history.map((entry) => [entry.key, 0]));
+  const userBytesByName = new Map(users.map((user) => [user.username, 0]));
+  const recentUsers = new Set<string>();
+  let liveConnections = 0;
+
+  records.forEach((record) => {
+    const dayKey = toDayKey(record.timestamp);
+    if (dailyTotals.has(dayKey)) {
+      dailyTotals.set(dayKey, (dailyTotals.get(dayKey) ?? 0) + record.bytes);
+    }
+
+    if (dayKey === currentDayKey && userBytesByName.has(record.username)) {
+      userBytesByName.set(record.username, (userBytesByName.get(record.username) ?? 0) + record.bytes);
+    }
+
+    const ageMs = now.getTime() - record.timestamp.getTime();
+    if (ageMs >= 0 && ageMs <= RECENT_WINDOW_MS) {
+      recentUsers.add(record.username);
+    }
+
+    if (ageMs >= 0 && ageMs <= CONNECTION_WINDOW_MS) {
+      liveConnections += 1;
+    }
+  });
+
+  const activeUsers = Array.from(userBytesByName.values()).filter((value) => value > 0).length;
+  const totalBytes = Array.from(userBytesByName.values()).reduce((sum, value) => sum + value, 0);
+  const daily = history.map((entry) => ({
+    day: entry.label,
+    bytes: dailyTotals.get(entry.key) ?? 0,
+    share: 0,
+  }));
+  const peak = Math.max(...daily.map((entry) => entry.bytes), 0);
+
+  daily.forEach((entry) => {
+    entry.share = peak > 0 ? entry.bytes / peak : 0;
+  });
+
+  return {
+    totalBytes,
+    liveConnections,
+    activeUsers,
+    daily,
+    userBytesByName,
+    recentUsers,
+  };
+}
+
+async function readParsedRecords(logPath: string): Promise<ParsedLogRecord[]> {
+  const logDir = path.dirname(logPath);
+
+  try {
+    const files = await fs.readdir(logDir);
+    const logFiles = files
+      .filter((file) => file === LOG_FILE_PREFIX || file.startsWith(`${LOG_FILE_PREFIX}.`))
+      .sort()
+      .slice(-HISTORY_DAYS - 2);
+
+    const parsed = await Promise.all(logFiles.map(async (file) => parseLogFile(path.join(logDir, file))));
+    return parsed.flat();
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code === 'ENOENT') {
+      return [];
+    }
+
+    throw error;
+  }
+}
+
+async function parseLogFile(filePath: string): Promise<ParsedLogRecord[]> {
+  try {
+    const content = await fs.readFile(filePath, 'utf8');
+    return content
+      .split(/\r?\n/)
+      .map(parseLogLine)
+      .filter((record): record is ParsedLogRecord => record !== null);
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code === 'ENOENT') {
+      return [];
+    }
+
+    throw error;
+  }
+}
+
+function parseLogLine(line: string): ParsedLogRecord | null {
+  const trimmed = line.trim();
+
+  if (!trimmed || trimmed.includes('Accepting connections') || trimmed.includes('Exiting thread')) {
+    return null;
+  }
+
+  const match = trimmed.match(
+    /^(\d{12}\.\d{3})\s+\d+\s+\d+\s+(\S+)\s+\S+\s+\S+\s+(\d+)\s+(\d+)\s+\d+\s+/,
+  );
+
+  if (!match) {
+    return null;
+  }
+
+  const [, rawTimestamp, username, bytesIn, bytesOut] = match;
+  if (username === '-') {
+    return null;
+  }
+
+  const timestamp = parse3proxyTimestamp(rawTimestamp);
+  if (!timestamp) {
+    return null;
+  }
+
+  return {
+    timestamp,
+    username,
+    bytes: Number(bytesIn) + Number(bytesOut),
+  };
+}
+
+function parse3proxyTimestamp(value: string): Date | null {
+  const match = value.match(/^(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})\.(\d{3})$/);
+  if (!match) {
+    return null;
+  }
+
+  const [, yy, mm, dd, hh, min, ss, ms] = match;
+  const year = 2000 + Number(yy);
+  const date = new Date(year, Number(mm) - 1, Number(dd), Number(hh), Number(min), Number(ss), Number(ms));
+
+  return Number.isNaN(date.getTime()) ? null : date;
+}
+
+function buildHistoryDays(today: Date, count: number) {
+  return Array.from({ length: count }, (_value, index) => {
+    const date = new Date(today);
+    date.setDate(today.getDate() - (count - index - 1));
+    return {
+      key: toDayKey(date),
+      label: date.toLocaleDateString('en-US', { weekday: 'short' }),
+    };
+  });
+}
+
+function startOfDay(date: Date): Date {
+  return new Date(date.getFullYear(), date.getMonth(), date.getDate());
+}
+
+function toDayKey(date: Date): string {
+  const month = String(date.getMonth() + 1).padStart(2, '0');
+  const day = String(date.getDate()).padStart(2, '0');
+  return `${date.getFullYear()}-${month}-${day}`;
+}

src/App.tsx

@@ -640,30 +640,38 @@ export default function App() {
     }
 
     let cancelled = false;
+    let intervalId: number | null = null;
+
+    const refreshSnapshot = async () => {
+      try {
+        const payload = await requestSnapshot(() =>
+          fetch('/api/state', {
+            headers: buildAuthHeaders(session.token),
+          }),
+        );
 
-    void requestSnapshot(() =>
-      fetch('/api/state', {
-        headers: buildAuthHeaders(session.token),
-      }),
-    )
-      .then((payload) => {
         if (!cancelled && payload) {
           setSnapshot(payload);
         }
-      })
-      .catch((error) => {
+      } catch (error) {
         if (error instanceof SessionExpiredError) {
           if (!cancelled) {
             resetSession();
           }
-          return;
         }
+      }
+    };
 
-        // Keep fallback snapshot for local UI and tests when backend is not running.
-      });
+    void refreshSnapshot();
+    intervalId = window.setInterval(() => {
+      void refreshSnapshot();
+    }, 5000);
 
     return () => {
       cancelled = true;
+      if (intervalId !== null) {
+        window.clearInterval(intervalId);
+      }
     };
   }, [session]);