Quick Start Guide

Get deferred deep linking working in a few minutes: one call to initialize, one call to get the deferred link.

Prerequisites

A DeepLinkNow account and an app created in the dashboard. Your app gets the link domain <alias>.deeplinknow.com.
Your app's public API key (dln_pub_…) from the dashboard's API Keys page. Creating an app issues one public key (for the SDKs) and one private key (for your server only). The public key is always shown on the API Keys page. The private key is shown once; if you lose it, regenerate it there.
Your iOS Team ID and Bundle ID, and your Android package name and SHA-256 certificate fingerprints, entered in the app's settings so DeepLinkNow can serve the .well-known files.

Any path on your link domain works as a deep link with no setup: https://<alias>.deeplinknow.com/products/123?ref=newsletter delivers /products/123 with ref=newsletter to your app.

To try an SDK before creating an app, use the demo key test_api_key. It returns mock responses.

Building with a coding agent? Use DeepLinkNow from Claude Code, Cursor or VS Code: install the MCP server in one click or one command (no key needed), then ask the agent to add DeepLinkNow. It reads these docs and checks your link domain.

React Native

npx expo install @deeplinknow/react-native   # Expo (development build)
npm install @deeplinknow/react-native && cd ios && pod install   # bare React Native

With Expo, add the config plugin with your link domains (["@deeplinknow/react-native", { "domains": ["<alias>.deeplinknow.com"] }]), which sets up Associated Domains and the Android intent filter. In bare React Native, add applinks:<alias>.deeplinknow.com and an autoVerify https intent filter by hand (see the React Native docs). Then:

import DeepLinkNow from "@deeplinknow/react-native";

await DeepLinkNow.initialize("dln_pub_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");

const link = await DeepLinkNow.checkDeferredDeepLink();
if (link) {
  // link.source: "clipboard" (iOS), "referrer" (Android) or "fingerprint"
  router.push({ pathname: link.path, params: link.queryParams });
}

Using Expo Router? Resolve the link in app/+native-intent.tsx with @deeplinknow/react-native/expo-router instead, so the app opens straight on the right screen. See Expo Router.

→ Next: Full React Native documentation

iOS (Swift)

pod 'DeepLinkNow', '~> 1.3'

Or add https://github.com/deeplinknow/dln-ios with Swift Package Manager. Add applinks:<alias>.deeplinknow.com under Signing & Capabilities → Associated Domains. Then:

import DeepLinkNow

await DeepLinkNow.initialize(config: DLNConfig(apiKey: "dln_pub_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"))

if let link = await DeepLinkNow.checkDeferredDeepLink() {
    // Pasteboard first (exact), then fingerprint (scored)
    router.open(path: link.path, query: link.queryParams)
}

Handle Universal Links when the app is already installed:

.onOpenURL { url in
    if let link = DeepLinkNow.parseLink(url) {
        router.open(path: link.path, query: link.queryParams)
    }
}

→ Next: Full iOS documentation

Android (Kotlin)

dependencies {
    implementation("com.deeplinknow:dln-android:1.3.0")
}

Add an autoVerify https intent filter for <alias>.deeplinknow.com to your link-handling activity. Then:

// Application.onCreate
DLN.init(context = this, apiKey = "dln_pub_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")

// First activity
lifecycleScope.launch {
    DLN.checkDeferredDeepLink().getOrNull()?.let { link ->
        // Install Referrer first (exact), then fingerprint (scored)
        router.open(link.path, link.queryParams)
    }
}

→ Next: Full Android documentation

Flutter

flutter pub add deeplinknow

The plugin wraps the native iOS and Android SDKs, which Swift Package Manager or CocoaPods and Gradle fetch for you. Add the Associated Domains entitlement and the autoVerify intent filter as for the native SDKs. Then:

import 'package:deeplinknow/deeplinknow.dart';

await DeepLinkNow.initialize('dln_pub_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx');

final link = await DeepLinkNow.checkDeferredDeepLink();
if (link != null) {
  // link.source: clipboard (iOS), referrer (Android) or fingerprint
  router.go(link.fullPath);
}

→ Next: Full Flutter documentation

How the deferred link is found

| | iOS | Android | |---|---|---| | Step 1 (exact) | Pasteboard: the landing page copied the tapped link | Play Install Referrer: the landing page passed a click ID to the Play Store | | Step 2 (best effort) | Fingerprint match | Fingerprint match | | Result | DeferredDeepLink with source, confidenceScore, matchQuality | same |

Every SDK returns the same DeferredDeepLink shape: path, queryParams, fullPath, url, source, confidenceScore (0–100) and matchQuality (HIGH / MEDIUM / LOW). Exact sources report 100 / HIGH.

About fingerprint matching

The server compares the device with clicks on your link pages from the last 1 hour and returns scored candidates. Each has a confidence_score (0–100) and a match_quality: HIGH (75+), MEDIUM (50–74), LOW (30–49).
An IP match is not required, because iCloud Private Relay and carrier NAT often give the app a different IP from the browser.
The time score decays across the 1-hour claim window, and missing data never counts as a match.
You choose the threshold. The optional minConfidence filter is off by default, so you get the server's best candidate and decide what to do with its matchQuality.

Troubleshooting

Links open the browser instead of the app

Check the dashboard settings (Team ID + Bundle ID, package name + SHA-256 fingerprints).
Open https://<alias>.deeplinknow.com/.well-known/apple-app-site-association and /.well-known/assetlinks.json. Changes can take up to 5 minutes to appear.
iOS caches the association file when the app is installed. Reinstall after changing it.
Android: run adb shell pm get-app-links <your.package>.

No deferred link on first launch

Make sure you call checkDeferredDeepLink() after initialize, and that the install happened within 1 hour of the click for fingerprint matching.
It returns a link only once per install. Call resetDeferredDeepLink() (or pass force: true) to test again.
Turn on enableLogs to see each step's outcome.
On iOS, tapping Don't Allow on the paste prompt skips the pasteboard step; fingerprint matching still runs.

Need Help?

Email: support@deeplinknow.com
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