Nexus-FCA v3.1.1 – 🏆 THE BEST, SAFEST, MOST STABLE FCA

Modern, safe, production‑ready Messenger (Facebook Chat) API layer with email/password + appState login, proxy support, random user agent, adaptive session & connection resilience, proactive cookie refresh, MQTT stability enhancements, delivery reliability safeguards, memory protection, and rich runtime metrics. Promise + callback compatible, TypeScript typed, minimal friction.

🎉 NEW in 3.1.1 - Industry Leading Features!

- ✅ Smart MQTT Recovery - Auto-refreshes Sequence ID on errors to prevent loops
- ✅ Proactive Lifecycle Management - Randomized reconnects (26-60m) to mimic human behavior
- ✅ Email/Password Login - Login with Facebook credentials (not just cookies!)
- ✅ Advanced Proxy Support - HTTP/HTTPS/SOCKS5 proxy for all connections
- ✅ Random User Agent - 14+ realistic user agents to avoid detection
- ✅ Enhanced Configuration - autoMarkRead, emitReady, bypassRegion, and more!
- ✅ Environment Variables - Full configuration via env vars
- ✅ Best-in-Class Stability - Proactive cookie refresh + MQTT recovery + session protection!

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✅ Core Value

| Pillar | What You Get |
|--------|--------------|
| Integrated Secure Login | Username / Password / TOTP 2FA → stable appstate generation & reuse |
| Session Resilience | Anchored User‑Agent continuity, adaptive safe refresh, lightweight token poke, periodic recycle |
| Connection Stability | Adaptive MQTT backoff, idle & ghost detection, layered post-refresh health probes, synthetic keepalives |
| Delivery Reliability | Multi-path message send fallback (MQTT → HTTP → direct) + delivery receipt timeout suppression |
| Memory Guard | Bounded queues, edit TTL sweeps, controlled resend limits |
| Observability | Health + memory + delivery metrics (api.getHealthMetrics(), api.getMemoryMetrics()) |
| Edit Safety | Pending edit buffer, ACK watchdog, p95 ACK latency tracking |
| Type Definitions | First-class index.d.ts with modern Promise signatures |

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🔄 What Changed in 3.0.0

Major version signals maturity & consolidation. No breaking public API changes versus late 2.1.x – upgrade is drop‑in. Temporary diagnostic harness removed; internal instrumentation formalized. Delivery receipt timeouts now intelligently retried & optionally auto-suppressed to protect outbound responsiveness.

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🚀 Quick Start

$3

``js
const login = require('nexus-fca');

(async () => {
const api = await login({ appState: require('./appstate.json') }, {
autoReconnect: true,
randomUserAgent: true // NEW!
});
console.log('Logged in as', api.getCurrentUserID());
api.listen((err, evt) => {
if (err) return console.error('Listen error:', err);
if (evt.body) api.sendMessage('Echo: ' + evt.body, evt.threadID);
});
})();
`

$3


`js
const login = require('nexus-fca');

(async () => {
const api = await login({
email: 'your-email@example.com', // NEW!
password: 'your-password' // NEW!
}, {
autoReconnect: true,
randomUserAgent: true, // NEW!
proxy: 'socks5://127.0.0.1:1080' // NEW!
});
console.log('✅ Logged in!');
api.listen((err, msg) => {
if (err) return console.error(err);
if (msg.body === 'ping') api.sendMessage('pong', msg.threadID);
});
})();
`

$3


`js
const login = require('nexus-fca');

(async () => {
const api = await login({ appState: require('./appstate.json') }, {
proxy: 'http://proxy.example.com:8080', // NEW!
randomUserAgent: true, // NEW!
autoMarkRead: true, // NEW!
emitReady: true, // NEW!
bypassRegion: 'PRN' // NEW!
});

api.on('ready', () => console.log('🚀 Bot ready!'));
api.listen((err, msg) => {
if (err) return console.error(err);
if (msg.body) api.sendMessage('Echo: ' + msg.body, msg.threadID);
});
})();
`

---


🧪 Key Runtime APIs


`js
api.setEditOptions({ maxPendingEdits, editTTLms, ackTimeoutMs, maxResendAttempts });
api.setBackoffOptions({ base, factor, max, jitter });
api.enableLazyPreflight(true); // Skip heavy validation if recent success
api.getHealthMetrics(); // uptime, reconnects, ack latency, delivery stats
api.getMemoryMetrics(); // queue sizes & guard counters
`

$3

`js
setInterval(() => {
const h = api.getHealthMetrics();
const m = api.getMemoryMetrics();
console.log('[HEALTH]', h?.status, 'acks', h?.ackCount, 'p95Ack', h?.p95AckLatencyMs);
console.log('[DELIVERY]', {
attempts: h?.deliveryAttempts,
success: h?.deliverySuccess,
failed: h?.deliveryFailed,
timeouts: h?.deliveryTimeouts,
disabledSince: h?.deliveryDisabledSince
});
console.log('[MEM]', m);
}, 60000);
`

---

🛡️ Safety & Stability Architecture

| Layer | Mechanism | Purpose |
|-------|-----------|---------|
| UA Continuity | Single anchored fingerprint | Avoid heuristic expiry & drift |
| Adaptive Refresh | Risk-aware timing bands | Token longevity without bursts |
| Lightweight Poke | Subtle fb_dtsg renewal | Keeps session warm quietly |
| Collision Guard | 45m spacing window | Prevent clustered maintenance events |
| Idle / Ghost Probe | Timed silent detection | Force reconnect on stale sockets |
| Periodic Recycle | Randomized (~6h ±30m) | Pre-empt silent degradation |
| Backoff Strategy | Exponential + jitter | Graceful network recovery |
| Delivery Suppression | Disable after repeated timeouts | Preserve send latency |

Disable heavy preflight if embedding inside a framework already doing checks:
`js
await login({ appState }, { disablePreflight: true });
`

---


🛰️ MQTT Enhancements (Since 3.1.x)

- Smart Recovery: Fetches fresh Sequence ID before reconnecting on errors (prevents stale token loops)
- Lifecycle Management: Proactive randomized reconnects (26-60m) to avoid long-session forced disconnects
- Adaptive reconnect curve (caps 5m)
- Layered post-refresh probes (1s / 10s / 30s)
- Synthetic randomized keepalives (55–75s)
- Structured error classification feeding metrics

---

✉️ Delivery Reliability

- Multi-path send fallback (MQTT publish → HTTP send → direct fallback)
- Per-attempt timeout & retry for message delivery receipts
- Automatic classification of transient timeouts (ETIMEDOUT / ECONNRESET / EAI_AGAIN)
- Adaptive suppression of delivery receipt calls when environment unstable (protects primary send throughput)

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🧠 Long Session Best Practices

1. Prefer appstate reuse (minimal credential logins).
2. Preserve persistent-device.json (only delete if forced challenge).
3. Don’t manually rotate User-Agent – built-in continuity handles it.
4. Inspect metrics before forcing reconnect; let backoff work.
5. Keep dependencies updated; review CHANGELOG for operational notes.

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🐐 Using with GoatBot V2 (Summary)

| Goal | Steps |
|------|-------|
| Generate appstate | Run credential login script → save appstate.json → configure GoatBot |
| Full replacement | Install nexus-fca → shim fb-chat-api/index.js exporting module |
| Direct require swap | Replace require('fb-chat-api') with require('nexus-fca') |

Minimal example:
`js
const login = require('nexus-fca');
(async () => {
const api = await login({ appState: require('./appstate.json') });
api.listen((err, event) => {
if (err) return console.error(err);
if (event.body === '!ping') api.sendMessage('pong', event.threadID);
});
})();
`

---


📚 Documentation Map


| Resource | Location |
|----------|----------|
| Full API Reference | DOCS.md |
| Feature Guides | docs/*.md |
| Configuration Reference | docs/configuration-reference.md |
| Safety Details | docs/account-safety.md |
| Examples | examples/ |

---

� Migrating 2.1.x → 3.0.0

| Area | Action Needed |
|------|---------------|
| Public API | None (fully compatible) |
| Diagnostics Harness | Removed (no action) |
| Delivery Metrics | Optionally surface in dashboards |
| Safety Manager (legacy) | Keep removed / unused |

---

🗂 Previous 2.1.x Highlights (Condensed)

| Version | Focus | Key Additions |
|---------|-------|---------------|
| 2.1.10 | Stabilization | Final 2.1.x meta adjustments |
| 2.1.8 | Safety Consolidation | Unified orchestrator, collision spacing, recycle suppression |
| 2.1.7 | Session Longevity | UA continuity, lightweight poke |
| 2.1.6 | Memory Guard | Queue pruning, edit TTL sweeps |
| 2.1.5 | Edit Reliability | PendingEdits buffer, ACK watchdog |

Full details remain in CHANGELOG.md`.

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⚠️ Disclaimer

Not affiliated with Facebook. Use responsibly and comply with platform terms & local laws.

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🤝 Contributing

Focused PRs improving stability, safety heuristics, protocol coverage, or typings are welcome.

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📜 License

Team Nexus

MIT © 2025 Nexus (Team Nexus)