AndroidSip

A small, understandable SIP softphone for Android — Kotlin + Jetpack Compose on top of the baresip SIP engine via a native JNI bridge.

AndroidSip lets you use a normal SIP account on a phone without depending on Android's deprecated SipManager API. Most of the SIP heavy lifting is done by baresip; the Android side handles permissions, notifications, audio routing, account storage, and making the call screen feel like a phone.

It is deliberately not a huge phone-system app — it registers one account and makes or receives calls, with a clean Material 3 UI.

Screenshots

Dial (dark)	Recents (dark)	Dial (light)	Recents (light)

Features

• 📞 Make outgoing calls from the dial screen
• 📲 Receive incoming calls while the foreground service is running
• 🔗 Opens sip:, sips:, and tel: links straight into the dialer
• 🕐 Recent-calls history
• 🎛️ Answer, reject, hang up, mute, hold, speaker, DTMF, and call transfer
• 🔌 UDP, TCP, or TLS transport
• 🔐 SIP password stored encrypted with the Android Keystore
• 🌐 Re-registers automatically when the network changes (Wi-Fi ↔ mobile)

Architecture

The app is written in Kotlin with Jetpack Compose. The native SIP engine is baresip, built as Android static libraries and linked into the app with CMake.

┌─────────────────────────────────────────────┐
│  Compose UI (dial / call / recents / setup) │
├─────────────────────────────────────────────┤
│  SipRuntime + SipForegroundService          │
├─────────────────────────────────────────────┤
│  SipEngine / NativeSipEngine (Kotlin)       │
├─────────────────────────────────────────────┤
│  JNI bridge (app/src/main/cpp)              │
├─────────────────────────────────────────────┤
│  baresip · libre · librem · OpenSSL         │
└─────────────────────────────────────────────┘

The Android package is dev.local.androidsip. Important parts of the project:

Path	What it is
app/src/main/java/dev/local/androidsip/	Android app, UI, service, runtime
app/src/main/java/dev/local/androidsip/sip/	SIP engine wrapper and baresip config
app/src/main/cpp/	JNI bridge for baresip
scripts/build_baresip_distribution.sh	downloads and builds the native libraries
THIRD_PARTY_NOTICES.md	notes about baresip and the vendored bridge code

Building

1. Build the native libraries

Before the Android app can build, the distribution/ folder must exist. It is created from juha-h/libbaresip-android by running:

scripts/build_baresip_distribution.sh

You need these tools installed:

• JDK
• Android SDK 36
• Android NDK 29.0.14206865
• CMake
• make, git, wget, pkg-config, automake, autoconf, libtool, unzip

If the NDK is not found automatically, set ANDROID_NDK_HOME to the NDK path.

2. Build the app

./gradlew testDebugUnitTest
./gradlew assembleDebug

If the Gradle wrapper JAR is missing, create it once from a machine that already has Gradle installed:

gradle wrapper --gradle-version 9.4.1

Known limitations

• Incoming calls only work while the foreground service is running.
• No Android Telecom integration yet.
• The app does not start itself after reboot.
• WebSocket SIP transports are not exposed — the pinned native build does not include the baresip websocket transport modules.
• netroam.so is not used; AndroidSip listens to Android network callbacks and asks baresip to re-register when the network changes.

Status

This is still an early personal project. The main call flow works, but it is not finished or polished yet. It should be a good base if you want to experiment with baresip on Android or need a small SIP client that is easy to understand.

License

AndroidSip is released under the MIT License. The bundled baresip, libre, librem, and OpenSSL libraries keep their own licenses — see THIRD_PARTY_NOTICES.md.