Complete setup guide: `lankapay_justpay_flutter`

This document is the full, ordered checklist for integrating the plugin. Follow it top to bottom the first time you integrate. Example XML in the Android and iOS sections matches common MID patterns for MNV cleartext hosts; always confirm values against your official MID.

Related files in this repo

Item	Location
Short overview	README.md
Example app	example/
Method channel name	`justpay_sdk/methods`

Before you write any code
Update your Flutter project
Add the Dart dependency
Android — LPTrusted AAR
Android — Gradle (app module)
Android — Config JSON in res/raw
Android — Permissions (AndroidManifest.xml)
Android — Network security (cleartext / MNV)
Android — ProGuard / R8 (release)
iOS — LPTrusted xcframework layout
iOS — CocoaPods
iOS — Bundle JSON
iOS — App Transport Security (ATS)
iOS — Xcode build settings
iOS — Embed & Sign the framework
Dart — Usage in your app
Config JSON — Required keys (reference)
Verify the integration
Migrating from embedded native JustPay code
Troubleshooting

1. Before you write any code

Obtain from your bank / LankaPay onboarding (not from this open-source repo):

Asset	Android	iOS
`justpay.json`	Place in `res/raw`	Add to Runner bundle
`mnv.json`	Place in `res/raw`	Required on iOS (add to Runner bundle)
Native SDK	`LPTrustedSDK.aar`	`LPTrustedSDK.xcframework`

2. Update your Flutter project

Use a stable Flutter channel and a Dart SDK compatible with the plugin’s pubspec.yaml (environment.sdk).
From your app root:
```
flutter upgrade
flutter doctor -v
```

Fix any Android SDK / Xcode / CocoaPods issues flutter doctor reports before continuing.

3. Add the Dart dependency

In your app’s pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter
  lankapay_justpay_flutter: ^0.2.22   # or path: / git: for your team

Then:

flutter pub get

Import:

import 'package:lankapay_justpay_flutter/lankapay_justpay_flutter.dart';

4. Android — LPTrusted AAR

Create the folder android/app/libs/ if it does not exist.
Copy the bank’s file LPTrustedSDK.aar into:

android/app/libs/LPTrustedSDK.aar

Use exactly this filename unless you change every Gradle reference yourself.
The plugin’s Android module uses compileOnly against:

$rootProjectDir/app/libs/LPTrustedSDK.aar

(same path relative to your Flutter app’s android/ folder). If this file is missing, Android Gradle fails with an explicit error from the plugin — that is expected until the AAR is present.

5. Android — Gradle (app module)

Edit android/app/build.gradle or android/app/build.gradle.kts.

Kotlin DSL (`build.gradle.kts`) — recommended pattern

Add a dependencies { } block (or merge into your existing one):

dependencies {
    // Required: packages LPTrusted into the APK. The plugin only compileOnly-compiles against it.
    implementation(files("libs/LPTrustedSDK.aar"))

    // MID-aligned versions (OkHttp 4.9.3, json-simple non-transitive).
    // The plugin also declares OkHttp + json-simple; duplicating here is optional but explicit.
    implementation("com.squareup.okhttp3:okhttp:4.9.3")
    implementation("com.googlecode.json-simple:json-simple:1.1.1") {
        isTransitive = false
    }
}

Groovy (`build.gradle`)

dependencies {
    implementation files('libs/LPTrustedSDK.aar')
    implementation 'com.squareup.okhttp3:okhttp:4.9.3'
    implementation('com.googlecode.json-simple:json-simple:1.1.1') {
        transitive = false
    }
}

If your build fails with duplicate classes from org.apache.commons.io.* or org.slf4j.*, add this in the app module:

configurations.configureEach {
    exclude(group = "commons-io", module = "commons-io")
    exclude(group = "org.slf4j", module = "slf4j-api")
}

configurations.all {
    exclude group: "commons-io", module: "commons-io"
    exclude group: "org.slf4j", module: "slf4j-api"
}

Trade-off (read this if you use file_picker 11+ or other Apache Tika stacks): Excluding external commons-io avoids duplicate class errors with a fat LPTrustedSDK.aar that already embeds org.apache.commons.io.*. Some dependencies (for example file_picker ≥ 11 on Android, which pulls tika-core) expect a **full Maven commons-io 2.x** on the classpath. With the exclude, **release R8** can fail with **missing** org.apache.commons.io.*classes. In that case you cannot satisfy both AAR and Tika from Gradle alone: **ask the bank / LankaPay for anLPTrustedSDKbuild that does not bundlecommons-io** (or uses a **relocated** / shaded package), **or** avoid the conflicting stack (for example pin **file_picker** to a version **without** tika-core`, if acceptable for your app). There is no Dart-only fix inside this plugin.

applicationId / flavors: The value of package inside justpay.json must match the built app’s applicationId (including flavor suffixes such as .dev). If they differ, identity and signing will fail.

Classpath mirror for LPTrusted (`ClassLoader#getResourceAsStream`)

Some LPTrustedSDK Android builds load justpay.json / mnv.json via the application class loader, for example context.getClassLoader().getResourceAsStream("res/raw/justpay.json") (and the same pattern for mnv.json). That is classpath (Java resources), not Resources.openRawResource. Putting files only under res/raw can satisfy openRawResource while getResourceAsStream("res/raw/…") still returns null unless those paths also exist as Java resources in the APK.

Fix: Copy the two JSON files from android/app/src/main/res/raw into a generated res/raw tree under build/ during preBuild, and add that folder to android.sourceSets.main.resources. Gradle then packages them so the classpath layout matches what the AAR expects; ConfigManager.getStatus can complete, Constants.DEVICE_ID can populate, and getDeviceID() can return a non-empty id in release as well as debug.

Kotlin DSL (android/app/build.gradle.kts) — register the task outside android { }, merge sourceSets inside your existing android { } block:

// LPTrusted may use ClassLoader.getResourceAsStream("res/raw/justpay.json").
// Mirrors host res/raw JSON into Java resources so that path resolves in the APK.

val prepareLpTrustedClasspathResources =
    tasks.register<Copy>("prepareLpTrustedClasspathResources") {
        from("$projectDir/src/main/res/raw") {
            include("justpay.json", "mnv.json")
        }
        into(layout.buildDirectory.dir("generated/lptrustedClasspathResources/res/raw"))
    }
tasks.named("preBuild").configure { dependsOn(prepareLpTrustedClasspathResources) }

android {
    // ...
    sourceSets {
        getByName("main") {
            resources.srcDir(layout.buildDirectory.dir("generated/lptrustedClasspathResources"))
        }
    }
}

Groovy (android/app/build.gradle) equivalent:

tasks.register("prepareLpTrustedClasspathResources", Copy) {
    from("$projectDir/src/main/res/raw") {
        include "justpay.json", "mnv.json"
    }
    into("$buildDir/generated/lptrustedClasspathResources/res/raw")
}
tasks.named("preBuild").configure { dependsOn("prepareLpTrustedClasspathResources") }

android {
    sourceSets {
        main {
            resources.srcDir("$buildDir/generated/lptrustedClasspathResources")
        }
    }
}

Rebuild your release variant (flutter build apk … --release, or your flavor) and verify logs (deviceIdLength should be > 0, not -1; getChallenge should see a non-empty deviceId).

Flavor note: The snippets copy from src/main/res/raw only. If flavor-specific trees hold different JSON (src/sit/res/raw/, etc.), extend the Copy task with additional from(…) blocks (or merged inputs) so the generated classpath res/raw matches what that flavor exposes through Resources for openRawResource.

Optional message for LankaPay / the bank: If their Android MID assumes res/raw alone is enough, the integration guide should clarify when config must also be reachable as ClassLoader.getResourceAsStream("res/raw/justpay.json") / …/mnv.json — host apps may need this Gradle wiring in addition to standard res/raw placement.

6. Android — Config JSON in `res/raw`

Copy your bank’s files to:
- android/app/src/main/res/raw/justpay.json
- android/app/src/main/res/raw/mnv.json
Resource names are the filenames without extension: justpay and mnv. Do not rename to justpay_config.json unless you also change native loading logic (this plugin expects those two names).
The plugin validates required keys before calling the SDK (see section 17).

Why bridge checks can pass while `getDeviceId` stays empty

Root cause (in the LankaPay Android AAR, not SHA / portal allowlists alone):

LPTrustedSDKManager.getDeviceID() does not read res/raw on every invocation. Typical builds expose a static Constants.DEVICE_ID populated only after ConfigManager.getStatus(context) runs successfully — and readJPJson(context) (and readMNVJson) must parse your JSON along that path. In some releases of the SDK, readJPJson uses context.getClassLoader().getResourceAsStream("res/raw/justpay.json") rather than openRawResource.

This Flutter plugin validates JSON using Resources.openRawResource (same logical files as res/raw). You can therefore see bridgeConfigValidation OK or a valid rawJustpayResId, while justpay.json / mnv.json are still missing from the classpath LPTrusted probes with getResourceAsStream("res/raw/…"). readJPJson then fails or DEVICE_ID is never set, getDeviceID() is null, and logs may show deviceIdLength: -1.

Put differently: LankaPay telling you provisioning or SHA has “nothing to configure” reflects their server side — this classpath vs Resources mismatch is how the client loads config on Android.

Remediation: Implement the classpath mirror described in section 5 (Classpath mirror for LPTrusted), then rebuild and re-check getDeviceID end-to-end.

7. Android — Permissions (`AndroidManifest.xml`)

JustPay / LPTrusted needs network access. Declaring network state is optional but useful for connectivity-aware behavior.

Minimum recommended for JustPay networking

Inside <manifest> (not inside <application>):

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

Other permissions

Typical banking apps also declare permissions for notifications, camera, biometric, and so on. Those are not required by this plugin unless your app uses those features. For JustPay-only networking, INTERNET (+ optionally ACCESS_NETWORK_STATE) is the core set.

Optional (only if your MID or bank doc says so): Some integrations mention telephony. Follow your MID if it requires READ_PHONE_STATE or similar.

Application attribute for network security

On <application>, point to your XML config (see next section). Example:

<application
    android:name="${applicationName}"
    android:label="your_app_name"
    android:icon="@mipmap/ic_launcher"
    android:networkSecurityConfig="@xml/network_security_config">
    <!-- activities, meta-data, etc. -->
</application>

8. Android — Network security (cleartext / MNV)

Mobile network validation (MNV) often uses HTTP to specific operator endpoints. Android 9+ blocks cleartext unless you allow it per domain. Without the right hosts, you may see UnknownServiceException: CLEARTEXT communication … not permitted.

UAT/sandbox MNV configs often hit 3lauth.ideabiz.lk and gsmacnvep.mobitel.lk in addition to production-style mobileauth.ideabiz.lk and gsmacnv.mobitel.lk. Include every host your mnv.json / MID uses.

Create android/app/src/main/res/xml/network_security_config.xml.
Example content (merge with your MID; add or remove domains per environment):

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">3lauth.ideabiz.lk</domain>
        <domain includeSubdomains="true">mobileauth.ideabiz.lk</domain>
        <domain includeSubdomains="true">gsmacnvep.mobitel.lk</domain>
        <domain includeSubdomains="true">gsmacnv.mobitel.lk</domain>
        <domain includeSubdomains="true">apihub.hutch.lk</domain>
        <domain includeSubdomains="true">heapihub.hutch.lk</domain>
    </domain-config>
</network-security-config>

Ensure AndroidManifest.xml references it (see section 7).

Important: If your bank’s MID lists different hosts for sandbox/production, adjust this list. The block above is a working reference for common LankaPay MNV hosts, not a substitute for verifying your MID.

9. Android — ProGuard / R8 (release)

This plugin publishes android/consumer-rules.pro, which Gradle merges into your app when minifyEnabled is true. 0.2.22 restores the narrow keeps from 0.2.18:
```
-keep class com.lankapay.justpay.** { *; }
```
Fat LPTrustedSDK AARs often bundle SpongyCastle, Apache Commons, OkHttp, and similar. If getDeviceId or signing works in debug but fails in release, add -keep rules your MID / bank documents to your app module’s proguard-rules.pro (for example org.spongycastle.**, **lk.lankapay.justpay_flutter.**, org.json.simple.**) — they are not all declared in this plugin’s consumer rules for 0.2.22.
ClassLoader vs Android resources: Some LPTrusted AAR builds require ClassLoader#getResourceAsStream("res/raw/justpay.json") (same for mnv.json). If openRawResource / plugin validation succeeds but getDeviceId stays empty (deviceIdLength: -1, getChallenge sees no deviceId), wire the classpath mirror from section 5 (Classpath mirror for LPTrusted) before blaming R8 or shrinking alone.
Resource shrinking (shrinkResources) — not fixed by consumer-rules.pro:

If your app sets isShrinkResources = true (common with release minify), the build may remove res/raw/justpay.json and res/raw/mnv.json because they are opened via Context#getIdentifier("justpay", "raw", …) — the shrinker often does not treat that as a reference. LPTrusted then cannot read config → getDeviceId() returns "" in release only (debug does not shrink). iOS is unaffected.

Add app/src/main/res/xml/keep_justpay_raw_resources.xml (name optional):
```
<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:tools="http://schemas.android.com/tools"
    tools:keep="@raw/justpay,@raw/mnv" />
```
Or temporarily set isShrinkResources = false to confirm.
If getDeviceId is non-empty in debug but empty in Android release while iOS release is fine, check (2) (classpath) and (3) (shrinkResources), then app-level ProGuard/R8 -keep rules as in (1).
If LankaPay or your bank supplies additional ProGuard rules, merge them into your app’s proguard-rules.pro (or the rules file your release build uses).
Always run a release build on a real device and exercise JustPay onboarding before store submission.

10. iOS — LPTrustedSDK and JSON (MID manual Xcode; Flutter disk path)

Follow your MID Section 7 (LankaPay): copy LPTrustedSDK.xcframework into the project folder, in Xcode use Add Files to “…” on the project, select the xcframework, Create groups, enable the Runner target, then Runner → General → Frameworks, Libraries, and Embedded Content and set LPTrustedSDK.xcframework to Embed & Sign. Add justpay.json the same way (Add Files…), with Runner target membership. mnv.json is required on iOS; add it to Runner as well so the plugin can validate dialog / hutch / mobitel before calling the SDK.

Flutter caveat: lankapay_justpay_flutter is a separate CocoaPods target. The plugin pod links LPTrustedSDK with FRAMEWORK_SEARCH_PATHS that include ios/, ios/Runner/, and common xcframework slice folders (ios-arm64, ios-arm64_x86_64-simulator, ios-arm64-simulator) under both LPTrustedSDK.xcframework locations — the linker needs -F on the slice that contains LPTrustedSDK.framework, not only the .xcframework root. From 0.2.14 this is built into the podspec; upgrade before adding a custom Podfile post_install. After you wire the framework in Xcode, keep the on-disk xcframework at ios/LPTrustedSDK.xcframework or ios/Runner/LPTrustedSDK.xcframework, then cd ios && pod install. If your bank’s xcframework uses other slice directory names, you can still append those paths in post_install for the lankapay_justpay_flutter target (same pattern as slice-specific FRAMEWORK_SEARCH_PATHS).

11. iOS — CocoaPods

Open a terminal at your_app/ios/.
Run:
```
pod install
```
If you change the plugin version or iOS native deps, run again:
```
pod install --repo-update
```
Open Runner.xcworkspace in Xcode (not Runner.xcodeproj alone).

Podfile platform: Use at least iOS 13.0 (MID). Your team may standardize on a higher minimum; that is fine as long as it meets MID requirements.

12. iOS — Bundle JSON

In Xcode, add justpay.json (Add Files…), enable Runner target membership, and confirm it under Build Phases → Copy Bundle Resources.
mnv.json is required on iOS. Add it using the same steps and confirm it is in Copy Bundle Resources; the plugin validates dialog, hutch, and mobitel.

Use the literal filenames justpay.json and mnv.json so Bundle.main.url(forResource:withExtension:) finds them.

13. iOS — App Transport Security (ATS)

iOS blocks insecure HTTP unless you declare exceptions. Add NSAppTransportSecurity for the same operator hosts you allow in Android cleartext (section 8). Use the same domain set as your network_security_config.xml (UAT often needs 3lauth.ideabiz.lk and gsmacnvep.mobitel.lk).

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSExceptionDomains</key>
    <dict>
        <key>3lauth.ideabiz.lk</key>
        <dict>
            <key>NSExceptionAllowsInsecureHTTPLoads</key>
            <true/>
        </dict>
        <key>mobileauth.ideabiz.lk</key>
        <dict>
            <key>NSExceptionAllowsInsecureHTTPLoads</key>
            <true/>
        </dict>
        <key>gsmacnvep.mobitel.lk</key>
        <dict>
            <key>NSExceptionAllowsInsecureHTTPLoads</key>
            <true/>
        </dict>
        <key>gsmacnv.mobitel.lk</key>
        <dict>
            <key>NSExceptionAllowsInsecureHTTPLoads</key>
            <true/>
        </dict>
        <key>apihub.hutch.lk</key>
        <dict>
            <key>NSExceptionAllowsInsecureHTTPLoads</key>
            <true/>
        </dict>
        <key>heapihub.hutch.lk</key>
        <dict>
            <key>NSExceptionAllowsInsecureHTTPLoads</key>
            <true/>
        </dict>
    </dict>
</dict>

How to add in Xcode: Open Runner → Info.plist as source code, or use Information Property List editor: add App Transport Security Settings → Exception Domains and mirror the keys above.

Again: confirm hosts with your MID for non-production environments.

14. iOS — Xcode build settings

Per MID:

Setting	Value
iOS Deployment Target	≥ 13.0 (MID minimum; your app may use a higher floor)
Enable Bitcode	No (MID)

In Xcode: Runner target → Build Settings → search “Bitcode” → Enable Bitcode → No.

15. iOS — Verify framework, JSON, and Pods

Run pod install --repo-update and open Runner.xcworkspace.
On disk: ios/LPTrustedSDK.xcframework or ios/Runner/LPTrustedSDK.xcframework exists.
In Xcode (Runner): General → Frameworks, Libraries, and Embedded Content shows LPTrustedSDK.xcframework with Embed & Sign; both justpay.json and mnv.json have Runner target membership and are in Copy Bundle Resources.

If Framework 'LPTrustedSDK' not found remains, reconfirm the xcframework on-disk path and rerun pod install --repo-update.

16. Dart — Usage in your app

final justPay = LankapayJustpayFlutter();

// 1) Optional: device id for your backend
final deviceId = await justPay.getDeviceId();

// 2) challenge from your bank API; contentToSign = e.g. terms text user agreed to
final result = await justPay.createIdentityAndSign(
  challenge: challengeFromApi,
  contentToSign: termsPlainText,
);

if (result.success) {
  final signature = result.signature;
  final mobileReference = result.mobileReference;
  // Send signature + mobileReference to your bank API per integration guide.
} else {
  // Show result.message to the user or log for support.
}

If your flow needs signature only (without MNV/mobile validation), use:

final signOnly = await justPay.createIdentityAndSignOnly(
  challenge: challengeFromApi,
  contentToSign: termsPlainText,
);

if (signOnly.success) {
  final signature = signOnly.signature;
  // mobileReference is empty in sign-only mode.
}

Threading: Native callbacks complete on the platform main thread; the plugin returns a Future to Dart as usual.

17. Config JSON — Required keys (reference)

These are validated before the SDK runs (mirroring typical native LPTrusted integration checks).

`justpay.json` (string values, non-empty after trim)

Key
`url`
`package`
`justpay_code`
`key_encipher`
`key_signer`
`justpay_cert`
`issuer`

`mnv.json`

Android: required in res/raw; keys below must be present and non-empty.

iOS: required in the app bundle; keys below must be present and non-empty.

Key
`dialog`
`hutch`
`mobitel`

If required keys are missing (or mnv.json is missing on Android/iOS), you get a structured error message in the Dart result.

18. Verify the integration

Use this checklist on a physical device when possible (MNV often depends on real carrier data).

flutter pub get succeeds.
cd ios && pod install succeeds.
Android: LPTrustedSDK.aar exists at android/app/libs/LPTrustedSDK.aar.
Android: justpay.json / mnv.json exist under res/raw/ with correct names.
Android: If getDeviceId / diagnostics suggest empty device id despite valid res/raw, the classpath mirror from section 5 (Classpath mirror for LPTrusted) is applied (prepareLpTrustedClasspathResources + sourceSets.main.resources).
Android: network_security_config.xml present and referenced in the manifest.
iOS: LPTrustedSDK.xcframework on disk under ios/ or ios/Runner/; Runner → Embed & Sign; both justpay.json and mnv.json in bundle; pod install succeeds.
iOS: justpay.json and mnv.json are in Copy Bundle Resources.
iOS: ATS NSExceptionDomains for every MNV HTTP host you use (mirror Android §8; confirm with MID).
justpay.json package matches Android applicationId.
getDeviceId returns a non-empty string when the SDK is correctly linked (empty often means iOS framework not linked or stub path).
createIdentityAndSign completes with success: true in a full test onboarding (uses bank sandbox as directed).

19. Migrating from embedded native JustPay code

If you previously registered a custom MethodChannel in MainActivity / FlutterActivity or AppDelegate that called LPTrusted directly:

Add lankapay_justpay_flutter to pubspec.yaml.
Remove your custom JustPay MethodChannel setup and any duplicate LPTrusted handler classes from the host app (the plugin registers justpay_sdk/methods on its own).
Replace your Dart bridge class with LankapayJustpayFlutter from this package.
Keep Firebase, notifications, other channels, and unrelated manifest keys as they are.
Run full JustPay regression on Android and iOS.

20. Troubleshooting

Symptom	What to check
Gradle: AAR not found	Path `android/app/libs/LPTrustedSDK.aar` and spelling of filename.
Gradle: duplicate classes (`org.apache.commons.io.` / `org.slf4j.`)	LPTrustedSDK AAR may already include `commons-io` and `slf4j-api`. Exclude external duplicates in app Gradle using `configurations.configureEach { exclude(...) }` (Kotlin DSL) or `configurations.all { exclude ... }` (Groovy), then run `flutter clean`.
Release R8: missing `org.apache.commons.io.*` after excluding `commons-io`	Same trade-off as above: Tika / full `commons-io` vs fat AAR. Prefer an updated LPTrustedSDK from the vendor, or remove/downgrade the dependency that pulls Tika (often `file_picker` ≥ 11).
Gradle: duplicate classes return when you remove the `commons-io` exclude	Expected: Maven `commons-io` and the AAR’s embedded copy both define `org.apache.commons.io.`. You need a non-fat* AAR or avoid pulling a second `commons-io`.
Android: “Missing res/raw/…”	Files named `justpay.json` / `mnv.json` under `app/src/main/res/raw/`.
Android: cleartext / SSL errors	`network_security_config.xml` domains vs MID; manifest `networkSecurityConfig`.
Android: `package` mismatch	`justpay.json` `package` vs `applicationId` (flavors).
Android: `getDeviceId` empty (`deviceIdLength: -1`) despite `bridgeConfigValidation` OK	LPTrusted may load JSON via `ClassLoader.getResourceAsStream("res/raw/…")`, not only `openRawResource`. Add the classpath mirror in section 5.
Android: `getDeviceId` empty only in release	Classpath mirror (section 5) when `res/raw` looks valid. `shrinkResources`: `tools:keep="@raw/justpay,@raw/mnv"` (§9) or `isShrinkResources = false`. `R8` stripping embedded AAR deps (SpongyCastle, bridge, etc.) — add `-keep` rules in the app `proguard-rules.pro` per MID; `0.2.22` plugin `consumer-rules` only keep `com.lankapay.justpay.` (see §9). Versions 0.2.19–0.2.21 published wider plugin consumer rules if you prefer that over app rules.
iOS: `Framework 'LPTrustedSDK' not found`	`ios/LPTrustedSDK.xcframework` or `ios/Runner/` on disk; `pod install --repo-update`; open `Runner.xcworkspace`. Use plugin ≥ 0.2.14 (slice `FRAMEWORK_SEARCH_PATHS`).
iOS: `import LPTrustedSDK` / link errors	Same + `pod install --repo-update`; `Runner.xcworkspace`. If your xcframework uses unusual slice folder names, append them in `post_install` for `lankapay_justpay_flutter`. Optional vendored pod.
iOS: HTTP load fails	ATS entries in Info.plist for operator hosts.
iOS: empty `getDeviceId`	Often stub (framework not linked: `#if canImport(LPTrustedSDK)` false) — fix xcframework disk path + `pod install`. On a linked device build, empty can mean SDK not initialized per MID.
Dart: `success: false` with config message	JSON keys missing/wrong; read `message` string.
Debug logs (recommended)	Android: view logcat and filter by tag `LankapayJustpay`. iOS: view the Xcode console for lines starting with `[LankapayJustpay]`. Dart: debug console output (only in debug mode).
Debug mocks (optional)	In debug builds you can enable failure simulation as success. This can help you continue UI/backend registration flow without native success. Enable with `LankapayJustpayFlutter(enableDebugMocks: true)`. Backend may still reject dummy `signature` or `mobileReference` if it validates strictly.
Release-only crashes	R8/ProGuard rules; test release on device.

Quick command recap

# From app root
flutter pub get
cd ios && pod install && cd ..

# Android
cd android && ./gradlew :app:assembleDebug && cd ..

# iOS (from app root)
flutter build ios --no-codesign

If anything in this guide conflicts with your bank’s MID, the MID wins.

Complete setup guide: `lankapay_justpay_flutter`

Table of contents

1. Before you write any code

2. Update your Flutter project

3. Add the Dart dependency

4. Android — LPTrusted AAR

5. Android — Gradle (app module)

Kotlin DSL (`build.gradle.kts`) — recommended pattern

Groovy (`build.gradle`)

Classpath mirror for LPTrusted (`ClassLoader#getResourceAsStream`)

6. Android — Config JSON in `res/raw`

Why bridge checks can pass while `getDeviceId` stays empty

7. Android — Permissions (`AndroidManifest.xml`)

Minimum recommended for JustPay networking

Other permissions

Application attribute for network security

8. Android — Network security (cleartext / MNV)

9. Android — ProGuard / R8 (release)

10. iOS — LPTrustedSDK and JSON (MID manual Xcode; Flutter disk path)

11. iOS — CocoaPods

12. iOS — Bundle JSON

13. iOS — App Transport Security (ATS)

14. iOS — Xcode build settings

15. iOS — Verify framework, JSON, and Pods

16. Dart — Usage in your app

17. Config JSON — Required keys (reference)

`justpay.json` (string values, non-empty after trim)

`mnv.json`

18. Verify the integration

19. Migrating from embedded native JustPay code

20. Troubleshooting

Quick command recap

Libraries

lankapay_justpay_flutter package

Complete setup guide: lankapay_justpay_flutter

Table of contents

1. Before you write any code

2. Update your Flutter project

3. Add the Dart dependency

4. Android — LPTrusted AAR

5. Android — Gradle (app module)

Kotlin DSL (build.gradle.kts) — recommended pattern

Groovy (build.gradle)

Classpath mirror for LPTrusted (ClassLoader#getResourceAsStream)

6. Android — Config JSON in res/raw

Why bridge checks can pass while getDeviceId stays empty

7. Android — Permissions (AndroidManifest.xml)

Minimum recommended for JustPay networking

Other permissions

Application attribute for network security

8. Android — Network security (cleartext / MNV)

9. Android — ProGuard / R8 (release)

10. iOS — LPTrustedSDK and JSON (MID manual Xcode; Flutter disk path)

11. iOS — CocoaPods

12. iOS — Bundle JSON

13. iOS — App Transport Security (ATS)

14. iOS — Xcode build settings

15. iOS — Verify framework, JSON, and Pods

16. Dart — Usage in your app

17. Config JSON — Required keys (reference)

justpay.json (string values, non-empty after trim)

mnv.json

18. Verify the integration

19. Migrating from embedded native JustPay code

20. Troubleshooting

Quick command recap

Libraries

lankapay_justpay_flutter package

Complete setup guide: `lankapay_justpay_flutter`

Kotlin DSL (`build.gradle.kts`) — recommended pattern

Groovy (`build.gradle`)

Classpath mirror for LPTrusted (`ClassLoader#getResourceAsStream`)

6. Android — Config JSON in `res/raw`

Why bridge checks can pass while `getDeviceId` stays empty

7. Android — Permissions (`AndroidManifest.xml`)

`justpay.json` (string values, non-empty after trim)

`mnv.json`