@devioarts/capacitor-mdns

mDNS plugin for Capacitor that supports Bonjour/mDNS advertisements and discovery.

Supported platforms: ✓ iOS ✓ Android ✓ Electron

Demo (sources): application or directly file

Install

npm install @devioarts/capacitor-mdns
npx cap sync

Android

/android/app/src/main/AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />

iOS

/ios/App/App/Info.plist

<key>NSLocalNetworkUsageDescription</key>
<string>It is needed for the correct functioning of the application</string>
<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsLocalNetworking</key>
    <true/>
</dict>
<key>NSBonjourServices</key>
<array>
    <string>_http._tcp</string>
</array>

ElectronJS

npm i [email protected]

Implementation example was developed on capacitor-electron base, if you run electron differently, you may need to adjust the code.

/electron/main.ts

// ...
import { mDNS } from '@devioarts/capacitor-mdns/electron/mdns'
// ...
const mdns = new mDNS();
// ...
app.whenReady().then(() => {
	//...
	mdns.init();
	//...
});
/* Or you can use app.on:ready (whenReady is recomended)
app.on('ready', () => {
	// ...
	mdns.init();
	// ...
});
*/

app.on('before-quit', async () => {
	// ...
	mdns.destroy();
	// ...
})
//...

electron/preload.cjs

//...
// THIS IS IMPORTANT FOR PLUGIN!
const {createMDNSAPI} = require("@devioarts/capacitor-mdns/electron/mdns-bridge.cjs");
//...
// THIS IS IMPORTANT FOR PLUGIN!
contextBridge.exposeInMainWorld('mDNS', createMDNSAPI({ ipcRenderer }));
contextBridge.exposeInMainWorld('mdns', createMDNSAPI({ ipcRenderer })) // alias

API

• startBroadcast(...)
• stopBroadcast()
• discover(...)
• Interfaces
• Type Aliases

Public API surface of the Capacitor mDNS plugin.

startBroadcast(...)

startBroadcast(options: MdnsBroadcastOptions) => Promise<MdnsBroadcastResult>

Start advertising a Bonjour/mDNS service.

| Param | Type | Description | | ------------- | --------------------------------------------------------------------- | ------------------------------------------------------------------ | | options | MdnsBroadcastOptions | - {@link MdnsBroadcastOptions} |

Returns: Promise<MdnsBroadcastResult>

stopBroadcast()

stopBroadcast() => Promise<MdnsStopResult>

Stop advertising the currently registered service (no-op if none).

Returns: Promise<MdnsStopResult>

discover(...)

discover(options?: MdnsDiscoverOptions | undefined) => Promise<MdnsDiscoverResult>

Discover services of a given type and optionally filter by instance name.

| Param | Type | Description | | ------------- | ------------------------------------------------------------------- | ---------------------------------------------------------------- | | options | MdnsDiscoverOptions | - {@link MdnsDiscoverOptions} |

Returns: Promise<MdnsDiscoverResult>

Interfaces

MdnsBroadcastResult

Result of startBroadcast(). Indicates whether advertising is active and the final service name. On failure, error is true and errorMessage describes the issue.

| Prop | Type | Description | | ------------------ | --------------------------- | -------------------------------------------------------------------- | | error | boolean | True if the operation failed. | | errorMessage | string | null | Error description or null on success. | | name | string | Final (possibly uniquified) service instance name. Empty on failure. | | publishing | boolean | Whether the advertiser is currently active. |

MdnsBroadcastOptions

Options for starting a Bonjour/mDNS advertisement.

| Prop | Type | Description | | ---------- | ------------------------------------------- | --------------------------------------------- | | type | string | Service type (including the trailing dot). | | name | string | Service instance name. | | port | number | TCP port to advertise. | | txt | MdnsTxt | Optional TXT key–value pairs (UTF-8 strings). |

MdnsStopResult

Result of stopBroadcast(). Indicates whether the advertiser is active after the call (normally false) and includes error information.

| Prop | Type | Description | | ------------------ | --------------------------- | ------------------------------------------------------------------- | | error | boolean | True if an error occurred while stopping. | | errorMessage | string | null | Error description or null on success. | | publishing | boolean | Whether the advertiser remains active (should be false on success). |

MdnsDiscoverResult

Result of discover(). Contains normalized services and error information.

| Prop | Type | Description | | ------------------- | --------------------------- | ------------------------------------------------------------------------------ | | error | boolean | True if discovery encountered an error (partial results may still be present). | | errorMessage | string | null | Error description or null when no error occurred. | | servicesFound | number | Convenience count equal to services.length. | | services | MdnsService[] | Normalized list of discovered services. |

MdnsService

Normalized description of a discovered Bonjour/mDNS service. Returned from {@link mDNSPlugin.discover}.

| Prop | Type | Description | | ------------ | ------------------------------------------- | ----------------------------------------------------------------------------------------- | | name | string | Instance name of the service (may be uniqued by the OS, e.g. "My App (2)"). | | type | string | Full service type including the trailing dot, e.g. "_http._tcp.". | | domain | string | Service domain; typically "local.". | | port | number | TCP port the service advertises. | | hosts | string[] | Resolved numeric IP addresses (IPv4/IPv6). | | txt | MdnsTxt | TXT dictionary (key → value). Usually present on iOS; Android NSD does not populate this. |

MdnsDiscoverOptions

Options for Bonjour/mDNS discovery.

| Prop | Type | Description | | ------------- | -------------------- | ---------------------------------------------------------------- | | type | string | Service type (including the trailing dot). | | name | string | Optional instance name filter (prefix-safe). | | timeout | number | Discovery timeout in milliseconds. | | useNW | boolean | iOS-only hint to use NWBrowser instead of NetServiceBrowser. |

Type Aliases

MdnsTxt

Key–value map for TXT records of a Bonjour/mDNS service. Values are UTF-8 strings; binary payloads are not supported by this API.

Record<string, string>

Record

Construct a type with a set of properties K of type T

{ [P in K]: T; }