LinkRouter (net.chaosengine.linkrouter)

A privacy-focused, rule-based URL router for Android: it intercepts http/https links (as the system default browser) and, per your user-defined rules, strips tracking/query params, rewrites URLs, and forwards them to a user-chosen browser — including private-window launchers for Chrome/Firefox. It is a router/dispatcher, not a browser: it never renders pages itself.

Features

• Rule engine: ordered rules matching exact host, *.subdomain, path prefix, or full regex; list order is priority, with specificity scoring as tie-breaking.
• Redirect formats: pattern-based extraction from redirect-style URLs via pure-JVM string processing (no network).
• Shortener-host handling: opt-in per-host resolution of t.co / bit.ly / is.gd-style redirects (pure-JVM redirect following with a WebView interstitial fallback), re-running the rule engine on the final URL. Off by default → zero network.
• URL query-param / tracker cleanup: global and domain-scoped stripping of tracking params (utm_*, gclid, fbclid, fbid, etc.) from the final launched URL only; never affects rule matching.
• Browser chooser with private-window support: dispatches to installed browsers with per-browser private capability (Firefox real-private verified; Chrome opens normally + honest warning when private is requested but unsupported); built-in in-app WebView target (real private, no cross-app leak); system/OS-default/chooser/ask-and-remember fallback modes.
• JSON import/export of rules, settings, shortener hosts, redirect formats, and param filters (local backup/restore, no sync).

Privacy

• Local-only rule and settings storage (Room, app-private storage). No URL history is ever persisted.
• No ads, no analytics, no telemetry, no third-party SDKs.
• Only the INTERNET permission is declared (a normal, install-granted permission), and it is exercised only if you enable the opt-in "shortener web resolution" feature for one or more hosts — all built-in shortener hosts ship disabled, so a default install makes zero network calls.
• See PRIVACY.md for the full privacy policy.

Requirements

• Android minSdk 26 (Android 8.0)
• Gradle: AGP 8.10.1, Kotlin 2.0.21

Build

./gradlew :app:assembleDebug      # debug APK (signed with the automatic debug key)
./gradlew :app:testDebugUnitTest  # JVM + Robolectric unit tests
./gradlew :app:bundleRelease      # Play AAB (unsigned unless you configure release signing, below)

Release signing

Release signing is entirely external-secret-driven (no keystore path or password ever lives in this repo). Provide all four via environment variables or gradle.properties keys (see gradle.properties.example):

Variable	Meaning
RELEASE_KEYSTORE	Path to the release keystore (.jks/.keystore)
RELEASE_KEY_ALIAS	Key alias inside the keystore
RELEASE_KEY_PASSWORD	Key password
RELEASE_STORE_PASSWORD	Keystore password

If any of the four is missing, the release build type is simply left unsigned and ./gradlew :app:bundleRelease still succeeds (producing an unsigned AAB) — useful for CI/dev. When all four are present, the AAB is signed with your keystore. Never commit a keystore or real passwords (both are git-ignored; gradle.properties.example keeps the keys blank).

Release builds also run R8 minification (isMinifyEnabled = true); debug builds stay unminified.

Project layout

app/src/main/java/net/chaosengine/linkrouter/:

Package / file	Purpose
DispatcherActivity.kt, LauncherActivity.kt	Transparent ACTION_VIEW interceptor + app-icon launcher
WebViewActivity.kt, ResolutionWebViewActivity.kt, SettleDetector.kt, ShortenerResolver.kt	In-app WebView target, ephemeral shortener-resolution WebView, pure-JVM redirect resolution
rules/	Rule model, Room repository, rule engine, validator, shortener hosts
browsers/	Browser discovery, per-browser private-launch strategies
fallback/	Chooser / OS-default / block / ask-and-remember fallbacks
settings/	App settings, param filters, redirect formats
ui/	Compose screens (rules list/editor, fallback config)
importexport/	JSON backup/restore

License

GNU GPL v3 — see LICENSE. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License.

Status

Current version: versionName = 0.1.0 (versionCode = 1), as defined in app/build.gradle.kts.