This project exists to test whether the DuckDuckGo Android cookies feature can be extracted into a Kotlin Multiplatform (KMP) core and reused by both Android and iOS while keeping native platform integrations.

This is a college study case / proof of concept, not an official DuckDuckGo initiative.

If policy and feature logic are shared once in KMP and only platform adapters stay native, cross-platform effort should decrease without losing native behavior where platform internals differ.

• Shared logic lives in commonMain and is consumed from Android and iOS.
• Android behavior remains functionally equivalent after migration.
• iOS can implement equivalent behavior through platform adapters.
• Future cookies policy changes are implemented once in shared code.

• Cookies feature config parsing and storage orchestration.
• Feature-toggle evaluation.
• Third-party cookie name matching logic.
• Shared utility logic (for example stacktrace redaction/base64 behavior).

• Forcing identical low-level DB/WebView implementation across platforms.
• Replacing native platform cookie APIs.
• Full app-wide migration in one step.

• cookies-kmp-core/src/commonMain: shared cookies domain logic.
• cookies-kmp-core/src/androidMain: Android actuals/adapters.
• cookies-kmp-core/src/appleMain: shared Apple adapters/contracts.
• cookies-kmp-core/src/iosMain: iOS adapters.
• cookies-kmp-core/src/macosMain: macOS adapters.
• cookies-kmp-core/src/commonTest: shared logic tests.

This KMP project is included from the Android repo as a composite build and consumed as:

• io.github.fernandafbmarques:cookies-kmp-core:0.1.1

The DuckDuckGo Android repo consumes this project from source via Gradle composite build.

Add to duckduckgo/Android/settings.gradle:

includeBuild("/Users/mariafernandafreitasbarbosamarques/IdeaProjects/CookiesKMP") {
    dependencySubstitution {
        substitute(module("io.github.fernandafbmarques:cookies-kmp-core"))
            .using(project(":cookies-kmp-core"))
    }
}

Then add in cookies/cookies-impl and cookies/cookies-store:

implementation "io.github.fernandafbmarques:cookies-kmp-core:0.1.1"

High-level steps to publish this library publicly:

1. Register a Sonatype Central account and a namespace for the chosen groupId.
2. Create a GPG signing key for release artifacts.
3. Configure Gradle maven-publish and signing with group, artifactId, and version.
4. Publish with ./gradlew publishAllPublicationsToMavenCentralRepository.
5. Release the staging repository in the Sonatype Central Portal.

• Namespace ownership issue was resolved by moving coordinates from com.duckduckgo.cookies to io.github.fernandafbmarques.
• Publishing is configured for Sonatype Central Portal using com.vanniktech.maven.publish.
• Artifact signing is configured via in-memory PGP keys in GitHub Actions.
• Release io.github.fernandafbmarques:cookies-kmp-core:0.1.1 was successfully deployed to Maven Central.
• Release workflow is release-only (-SNAPSHOT versions are rejected by Central Portal and blocked in CI).

• KMP core created and wired to Android cookies modules.
• Android wrappers now delegate selected business logic to KMP core.
• Android unit tests for cookies-store and cookies-impl pass.
• iOS compilation/tests require a valid local Xcode CLI setup.

1. Bump project version for the next release cycle (for example 0.1.2) and maintain release notes per tag.
2. Add iOS concrete adapters and parity tests against Android expected outputs.
3. Add a small consumer smoke test project that resolves io.github.fernandafbmarques:cookies-kmp-core from Maven Central.
4. Continue replacing duplicated host-app logic with shared KMP calls, removing wrappers only after parity confirmation.

From Android repo root:

./gradlew :cookies-store:testDebugUnitTest :cookies-impl:testDebugUnitTest
./gradlew :cookies-kmp:cookies-kmp-core:testDebugUnitTest

From this KMP repo root (Apple packaging):

./scripts/build_apple_xcframework.sh
./scripts/compute_spm_checksum.sh
# then update the Apple package manifest for a release tag:
./scripts/update_spm_manifest.sh 0.1.2 <checksum>

• iOS adapter parity for platform-specific cookie behavior.
• Continued AGP/Kotlin MPP version compatibility drift.
• Keeping Android behavior exactly stable during incremental migration.

See also:

• BUSINESS_CASE.md
• CODEX_CONTEXT.md
• CODEX_WORKPLAN.md
• KMP_UNIFIED_ROADMAP.md
• apple-spm/CookiesKMP/Package.swift