DuckCMP

Open-source Consent Management Platform SDK for Android & iOS

https://duckcmp.com

Quick Start · Configuration · API · WebView Bridge · Docs

---

• Two native SDKs — Kotlin + Compose (Android), Swift + SwiftUI (iOS)
• 4 layout options — Banner, Popup, Fullscreen, Bottom Sheet
• Fully customizable — theme, categories, labels, button order
• WebView bridge — __duckcmp JS interface for hybrid apps
• Zero dependencies — no third-party libraries beyond platform frameworks

Quick Start

Android

// 1. Add GitHub Packages repo (settings.gradle.kts)
dependencyResolutionManagement {
repositories {
maven {
url = uri("https://maven.pkg.github.com/analytics-debugger/duckcmp")
credentials {
username = providers.gradleProperty("gpr.user").orNull
?:System.getenv("GITHUB_ACTOR")
password = providers.gradleProperty("gpr.key").orNull
?:System.getenv("GITHUB_TOKEN")
}
}
}
}
// app/build.gradle.kts
dependencies {
implementation("com.analytics.debugger:duck-cmp:0.0.1-alpha")
}

// 2. InitializeDuckCMP.initialize(context)
// 3. Show dialogif (DuckCMP.shouldShowDialog()) {
DuckCMP.showConsentDialog(activity)
}
// 4. Check consentval hasAnalytics =DuckCMP.hasConsent(2) // category ID 2 = Analyticsval status =DuckCMP.getConsentStatus() // UNKNOWN, ACCEPTED, REJECTED, PARTIAL

iOS

// 1. Add via Swift Package Manager
// Xcode: File > Add Package Dependencies
// 2. Initialize
import DuckCMP
DuckCMP.initialize()
// 3. Show dialog (SwiftUI)
.fullScreenCover(isPresented: $showConsent){ConsentDialogView{
showConsent =false}}
// 4. Check consent
lethasAnalytics=DuckCMP.hasConsent(categoryId:2)letstatus=DuckCMP.getConsentStatus()

Default Categories

ID	Category	Description	Required
1	Necessary	Essential for the app to function	Yes (always on)
2	Analytics	Help us understand how you use the app	No
3	Marketing	Used to deliver personalized ads	No
4	Preferences	Remember your settings and choices	No

Configuration

All configuration is done through ConsentConfig. Every property has a sensible default.

Full Example

DuckCMP.initialize(context, ConsentConfig(
// Labels
dialogTitle ="Your Privacy Matters",
dialogMessage ="Choose which data categories you allow.",
acceptAllLabel ="Allow All",
rejectAllLabel ="Deny All",
saveChoicesLabel ="Confirm My Choices",
manageLabel ="Manage Preferences",
// Behavior
requireConsent =true, // must choose before dismissing
showCategoryToggles =true,
// Layout: BANNER, POPUP, FULLSCREEN, BOTTOM_SHEET
layout =ConsentLayout.POPUP,
// Button order (omit to hide)
buttons =listOf(
ConsentButton.SAVE_CHOICES,
ConsentButton.ACCEPT_ALL,
ConsentButton.REJECT_ALL
),
// Theme
theme =ConsentTheme(
primaryColor =0xFF6200EE,
backgroundColor =0xFFFFFFFF,
textColor =0xFF333333,
titleColor =0xFF111111,
buttonTextColor =0xFFFFFFFF,
secondaryButtonTextColor =0xFF6200EE,
cornerRadius =16f,
overlayColor =0x99000000
),
// Custom categories
categories =listOf(
ConsentCategory(id =1, name ="Essential", description ="...", isRequired =true),
ConsentCategory(id =2, name ="Performance", description ="..."),
ConsentCategory(id =3, name ="Targeting", description ="..."),
ConsentCategory(id =4, name ="Social", description ="...")
)
))

ConsentConfig

Property	Type	Default	Description
categories	List<ConsentCategory>	4 defaults	Consent categories shown to the user
dialogTitle	String	"Privacy Settings"	Heading text
dialogMessage	String	"We use cookies..."	Body text
acceptAllLabel	String	"Accept All"	Accept button text
rejectAllLabel	String	"Reject All"	Reject button text
saveChoicesLabel	String	"Save Choices"	Save toggles button text
manageLabel	String	"Manage Preferences"	Expand toggles link text
showCategoryToggles	Boolean	true	Show per-category toggles
requireConsent	Boolean	false	Block dismiss without choosing
buttons	List<ConsentButton>	All 4	Which buttons, in what order
layout	ConsentLayout	POPUP	Dialog presentation style
theme	ConsentTheme	Default	Visual customization

ConsentCategory

Property	Type	Description
id	Int	Unique identifier for hasConsent(id)
name	String	Display name in the dialog
description	String	Explanation shown to the user
isRequired	Boolean	If true, toggle is always on and disabled

ConsentTheme

Property	Default	Description
primaryColor	0xFF1976D2	Buttons, toggles, active elements
backgroundColor	0xFFFFFFFF	Dialog background
textColor	0xFF212121	Body text
titleColor	0xFF212121	Heading text
buttonTextColor	0xFFFFFFFF	Primary button label
secondaryButtonTextColor	0xFF1976D2	Outlined button text
cornerRadius	12f	Corner radius (dp)
overlayColor	0x80000000	Background dim overlay

ConsentButton

Value	Style	Description
ACCEPT_ALL	Primary filled	Accept all categories
REJECT_ALL	Outlined	Reject all optional categories
SAVE_CHOICES	Primary filled	Save individual toggle selections
MANAGE	Text link	Expand to show category toggles

Order in the list = order on screen. Omit a button to hide it.

ConsentLayout

Value	Description
BANNER	Compact bottom bar. Expands on "Manage".
POPUP	Centered modal dialog (default).
FULLSCREEN	Full-screen overlay. Maximum attention.
BOTTOM_SHEET	Draggable sheet (~85% height). Scrollable.

API Reference

All methods are static on DuckCMP.

Method	Returns	Description
initialize(context, config?)	void	Initialize SDK. Call once at app start.
showConsentDialog(activity)	void	Show dialog with configured layout.
getConsentStatus()	ConsentStatus	UNKNOWN, ACCEPTED, REJECTED, or PARTIAL
getConsentResult()	ConsentResult?	Full consent snapshot with per-category details
hasConsent(categoryId)	Boolean	Check if a category is consented
shouldShowDialog()	Boolean	true if no consent stored yet
saveConsent(result)	void	Programmatically save consent
reset()	void	Clear all stored consent
getConfig()	ConsentConfig	Get current configuration
updateConfig(config)	void	Update config at runtime
addCallback(callback)	void	Register for consent events
removeCallback(callback)	void	Unregister a listener
attachToWebView(webView)	void	Inject __duckcmp JS bridge
detachFromWebView(webView)	void	Remove JS bridge

ConsentCallback

interfaceConsentCallback {
funonConsentGiven(result:ConsentResult) // user accepted/rejected/saved
funonConsentRevoked() // reset() called
funonDialogDismissed() // dialog closed
}

ConsentStatus

Value	Meaning
UNKNOWN	No consent stored yet
ACCEPTED	All categories consented
REJECTED	All optional categories rejected
PARTIAL	Some accepted, some rejected

WebView Bridge

For hybrid apps, inject the __duckcmp JavaScript interface:

// AndroidDuckCMP.attachToWebView(webView)

// iOS
DuckCMP.attachToWebView(webView)

Then in your web content:

if(window.__duckcmp){// Readconststatus=window.__duckcmp.getStatus();// "ACCEPTED"consthasAds=window.__duckcmp.hasConsent(3);// true/falseconstfull=JSON.parse(window.__duckcmp.getConsent());// Writewindow.__duckcmp.setConsent(JSON.stringify({categories: [{id: 1,consent: true},{id: 2,consent: true},{id: 3,consent: false},{id: 4,consent: true}]}));// Show native dialog from JSwindow.__duckcmp.showConsentDialog();// Listen for native changeswindow.__duckcmp.onConsentChanged=function(state){console.log("Consent updated:",state);};}

How it works

Platform	Mechanism
Android	@JavascriptInterface via addJavascriptInterface(). Synchronous reads.
iOS	WKScriptMessageHandler + JS polyfill. Reads from pre-populated _state.

Native consent changes are automatically pushed to all attached WebViews. WebView changes persist to native storage and trigger callbacks.

Storage

Consent is persisted using platform-native storage:

Platform	Backend
Android	SharedPreferences (named "duckcmp")
iOS	UserDefaults.standard

Keys

duckcmp_result // Full JSON consent result
duckcmp_timestamp // Unix timestamp of last consent
duckcmp_status // "ACCEPTED" | "REJECTED" | "PARTIAL" | "UNKNOWN"
duckcmp_category_{id} // Per-category boolean (e.g. duckcmp_category_2 = true)

Per-category keys let you check consent from anywhere without initializing the SDK — useful in background services, content providers, or broadcast receivers.

Project Structure

open_source_cmp_sdk/
├── android/
│ ├── duck-cmp/ # Library module (AAR)
│ │ └── src/main/kotlin/com/analyticsdebugger/cmp/
│ │ ├── DuckCMP.kt # Public API singleton
│ │ ├── ConsentCallback.kt
│ │ ├── model/
│ │ │ ├── ConsentConfig.kt
│ │ │ ├── ConsentCategory.kt
│ │ │ ├── ConsentTheme.kt
│ │ │ ├── ConsentLayout.kt
│ │ │ ├── ConsentButton.kt
│ │ │ ├── ConsentResult.kt
│ │ │ └── ConsentStatus.kt
│ │ ├── storage/
│ │ │ ├── ConsentStorage.kt
│ │ │ └── StorageKeys.kt
│ │ ├── ui/
│ │ │ ├── ConsentDialog.kt
│ │ │ └── ConsentDialogActivity.kt
│ │ └── webview/
│ │ └── ConsentWebViewBridge.kt
│ └── sample-app/
├── ios/
│ ├── DuckCMP/ # Swift Package
│ │ └── Sources/DuckCMP/
│ │ ├── DuckCMP.swift
│ │ ├── ConsentConfig.swift
│ │ ├── ConsentCategory.swift
│ │ ├── ConsentTheme.swift
│ │ ├── ConsentLayout.swift
│ │ ├── ConsentResult.swift
│ │ ├── ConsentStatus.swift
│ │ ├── ConsentStorage.swift
│ │ ├── StorageKeys.swift
│ │ ├── UI/
│ │ │ └── ConsentDialogView.swift
│ │ └── WebView/
│ │ └── ConsentWebViewBridge.swift
│ └── SampleApp/
├── public_site/ # Documentation website
├── LICENSE
└── README.md

Requirements

Platform	Minimum
Android	API 24 (Android 7.0)
iOS	iOS 15.0
Kotlin	1.9+
Swift	5.9+
JDK	17

License

MIT License. See LICENSE.