Network

The default connectivity surface in Zynth is connectivity, which provides simple, cross-platform monitoring of device connectivity and internet reachability.

It abstracts the differences between iOS (Network framework), Android (ConnectivityManager), and Web (Navigator.onLine) to provide a unified reactive state.

To monitor network state on Android, you must declare the following permissions in your app.json.

{
  "zynth": {
    "android": {
      "permissions": [
        "android.permission.ACCESS_NETWORK_STATE",
        "android.permission.INTERNET"
      ]
    }
  }
}

Basic usage

Synchronous State

Access the current connectivity snapshot using connectivity.current.

import { connectivity } from "@zynthjs/apis";

const { isConnected, type } = connectivity.current;

if (!isConnected) {
  console.log("Offline mode active.");
}

Connection Subscriptions

React to changes in network quality or type (e.g., switching from WiFi to Cellular).

import { connectivity } from "@zynthjs/apis";

const unsubscribe = connectivity.subscribe((state) => {
  if (state.type === "cellular" && state.isExpensive) {
    console.log("Heads up: Using metered data.");
  }
});

Advanced

Network Types

Zynth classifies connections into the following stable categories:

• wifi: High-speed wireless.
• cellular: Mobile data (LTE, 5G, etc.).
• ethernet: Local wired connection.
• vpn: Active VPN tunnel.
• none: No network hardware active.
• unknown: OS could not determine the connection medium.

Special cases

• Internet Reachability: isConnected represents the hardware state (the device is connected to a router/tower), while isInternetReachable represents whether a packet can actually reach the public internet (best-effort calculation by the OS).
• Expensive Connections: On Android and iOS, Zynth correctly identifies “metered” connections (Cellular or specific WiFi hotspots) to help apps minimize data consumption.

API Reference

connectivity.current: NetworkState

Returns the current frozen snapshot of the connectivity status.

connectivity.subscribe(listener: (state: NetworkState) => void): () => void

Adds a reactive listener for connectivity changes. Returns an unsubscribe function.

connectivity.onChange(listener: (state: NetworkState) => void): () => void

Alias for subscribe().

connectivity.refresh(): NetworkState

Triggers an immediate re-poll of the native connectivity manager.

NetworkState (Type)

• isConnected: boolean
• isInternetReachable: boolean
• type: NetworkType
• isExpensive: boolean

Legacy compatibility

Network.currentState, Network.subscribe(), Network.addEventListener("change", ...), and Network.refresh() remain available for compatibility.