objectbox · greenrobot-team · Oct 1, 2025 · Jul 28, 2025 · Sep 30, 2025 · Sep 30, 2025
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
@@ -82,7 +82,8 @@ jobs:
           ../tool/pub.sh run test
       - name: Install ObjectBox C library
         working-directory: objectbox_test
-        run: ../install.sh
+        # Use Sync-enabled library to at least partially run sync_test.dart
+        run: ../install.sh --sync
       - name: Library Test
         working-directory: objectbox_test
         # Set concurrency=1 to run only one test suite (== test file) at a time to make it easier to

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
@@ -90,7 +90,8 @@ generator-integ-tests:
     - dart test --concurrency=1 --reporter expanded
     # ObjectBox tests
     - cd ../objectbox_test
-    - ../install.sh
+    # Use Sync-enabled library to at least partially run sync_test.dart
+    - ../install.sh --sync
     - dart pub get
     - dart run build_runner build
     # Set concurrency=1 to run only one test suite (== test file) at a time.

diff --git a/dev-doc/updating-c-library.md b/dev-doc/updating-c-library.md
@@ -19,37 +19,37 @@ for the binding update script (see below) and
 for Flutter (`flutter_libs` and `sync_flutter_libs` plugins) on Linux and Windows:
 
 ```bash
-./tool/set-c-version.sh 4.3.1
+./tool/set-c-version.sh 5.0.0-rc
 ```
 
 ```text
-* Update ObjectBox database for Flutter Linux/Windows, Dart Native apps to [4.3.1](https://github.com/objectbox/objectbox-c/releases/tag/v4.3.1).
+* Update ObjectBox database for Flutter Linux/Windows, Dart Native apps to [5.0.0-rc](https://github.com/objectbox/objectbox-c/releases/tag/v5.0.0-rc).
 ```
 
 ```text
-Update C library [4.3.0 -> 4.3.1]
+Update C library [4.3.1 -> 5.0.0-rc]
 
-Includes database 4.3.1-2025-07-28
+Includes database 5.0.0-2025-09-27
 ```
 
 ### Android
 
 For the Flutter plugins on Android ([view releases](https://github.com/objectbox/objectbox-java/releases)):
 
 ```bash
-./tool/set-android-version.sh 4.3.1
+./tool/set-android-version.sh 5.0.1
 ```
 
 ```text
-* Update ObjectBox database for Flutter Android apps to 4.3.1.
+* Update ObjectBox database for Flutter Android apps to 5.0.1.
   If your project is [using Admin](https://docs.objectbox.io/data-browser#admin-for-android), make 
-  sure to update to `io.objectbox:objectbox-android-objectbrowser:4.3.1` in `android/app/build.gradle`.
+  sure to update to `io.objectbox:objectbox-android-objectbrowser:5.0.1` in `android/app/build.gradle`.
 ```
 
 ```text
-Update Android library [4.3.0 -> 4.3.1]
+Update Android library [4.3.1 -> 5.0.1]
 
-Includes C API 4.3.1 and database 4.3.1-2025-08-02
+Includes C API 5.0.0 and database 5.0.0-2025-09-27
 ```
 
 Note: the embedded C API and ObjectBox version can be looked up
@@ -60,18 +60,18 @@ from the relevant objectbox repository release tag (like `java-4.1.0`).
 For the Flutter plugins on iOS/macOS ([view releases](https://github.com/objectbox/objectbox-swift/releases))
 
 ```bash
-./tool/set-swift-version.sh 4.4.1
+./tool/set-swift-version.sh 5.0.0
 ```
 
 ```text
-* Update ObjectBox database for Flutter iOS/macOS apps to 4.3.1.
+* Update ObjectBox database for Flutter iOS/macOS apps to 5.0.0.
   For existing projects, run `pod repo update` and `pod update ObjectBox` in the `ios` or `macos` directories.
 ```
 
 ```text
-Update macOS/iOS library [4.3.0 -> 4.4.1]
+Update macOS/iOS library [4.4.1 -> 5.0.0]
 
-Includes C API 4.3.1 and database 4.3.1-2025-08-02
+Includes C API 5.0.0 and database 5.0.0-2025-09-27
 ```
 
 Note: the embedded C API and ObjectBox version can be looked up 
@@ -98,5 +98,5 @@ Then manually:
 - Commit as
 
 ```text
-Update C-API [4.3.0 -> 4.3.1]
+Update C-API [4.3.1 -> 5.0.0]
 ```
diff --git a/flutter_libs/android/build.gradle b/flutter_libs/android/build.gradle
@@ -50,6 +50,6 @@ android {
         // ObjectBox Android library that includes an ObjectBox C library version compatible with
         // the C API binding of the ObjectBox Dart package.
         // https://central.sonatype.com/search?q=g:io.objectbox%20objectbox-android
-        implementation "io.objectbox:objectbox-android:4.3.1"
+        implementation "io.objectbox:objectbox-android:5.0.1"
     }
 }
diff --git a/flutter_libs/ios/objectbox_flutter_libs.podspec b/flutter_libs/ios/objectbox_flutter_libs.podspec
@@ -18,7 +18,7 @@ Pod::Spec.new do |s|
   s.source_files     = 'Classes/**/*'
 
   s.dependency 'Flutter'
-  s.dependency 'ObjectBox', '4.4.1'
+  s.dependency 'ObjectBox', '5.0.0'
 
   # Flutter.framework does not contain a i386 slice.
   s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'EXCLUDED_ARCHS[sdk=iphonesimulator*]' => 'i386' }

diff --git a/flutter_libs/linux/CMakeLists.txt b/flutter_libs/linux/CMakeLists.txt
@@ -47,7 +47,7 @@ target_link_libraries(${PLUGIN_NAME} PRIVATE PkgConfig::GTK)
 # ----------------------------------------------------------------------
 # Download and add objectbox-c prebuilt library.
 
-set(OBJECTBOX_VERSION 4.3.1)
+set(OBJECTBOX_VERSION 5.0.0-rc)
 
 set(OBJECTBOX_ARCH ${CMAKE_SYSTEM_PROCESSOR})
 if (${OBJECTBOX_ARCH} MATCHES "x86_64")

diff --git a/flutter_libs/macos/objectbox_flutter_libs.podspec b/flutter_libs/macos/objectbox_flutter_libs.podspec
@@ -18,7 +18,7 @@ Pod::Spec.new do |s|
   s.source_files     = 'Classes/**/*'
 
   s.dependency 'FlutterMacOS'
-  s.dependency 'ObjectBox', '4.4.1'
+  s.dependency 'ObjectBox', '5.0.0'
 
   s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES' }
   s.swift_version = '5.3'

diff --git a/flutter_libs/windows/CMakeLists.txt b/flutter_libs/windows/CMakeLists.txt
@@ -56,7 +56,7 @@ set(objectbox_flutter_libs_bundled_libraries
 # ----------------------------------------------------------------------
 # Download and add objectbox-c prebuilt library.
 
-set(OBJECTBOX_VERSION 4.3.1)
+set(OBJECTBOX_VERSION 5.0.0-rc)
 
 set(OBJECTBOX_ARCH ${CMAKE_SYSTEM_PROCESSOR})
 if (${OBJECTBOX_ARCH} MATCHES "AMD64")

diff --git a/install.sh b/install.sh
@@ -5,7 +5,7 @@ set -eu
 # It's important that the generated dart bindings and the c-api library version match. Dart won't error on C function
 # signature mismatch, leading to obscure memory bugs.
 # For how to upgrade the version see dev-doc/updating-c-library.md
-cLibVersion=4.3.1
+cLibVersion=5.0.0-rc
 os=$(uname)
 cLibArgs="$*"
 

diff --git a/objectbox/CHANGELOG.md b/objectbox/CHANGELOG.md
@@ -1,8 +1,26 @@
 ## latest
 
+### Sync
+
+- Support Sync server version 5.0.
+  - **User-Specific Data Sync**: support configuring [Sync filter](https://sync.objectbox.io/sync-server/sync-filters)
+    variables on `SyncClient`.
+
+### Other Changes
+
 * Flutter packages are compiled with Android SDK 35 to support Android Gradle Plugin 8.13 
   [#755](https://github.com/objectbox/objectbox-dart/issues/755). They are also built using a
   language level of Java 11.
+* Update ObjectBox database for Flutter Linux/Windows, Dart Native apps to [5.0.0-rc](https://github.com/objectbox/objectbox-c/releases/tag/v5.0.0-rc).
+  * ToOne relations: when deleting an object with an ID larger than the maximum 32-bit unsigned
+    integer (`4_294_967_295`) that is used as the target object of a ToOne, correctly re-set the
+    target ID of the ToOne to `0`. [#740](https://github.com/objectbox/objectbox-dart/issues/740)
+* Update ObjectBox database for Flutter Android apps to 5.0.1.
+  If your project is [using Admin](https://docs.objectbox.io/data-browser#admin-for-android), make
+  sure to update to `io.objectbox:objectbox-android-objectbrowser:5.0.1` in `android/app/build.gradle`.
+* Update ObjectBox database for Flutter iOS/macOS apps to 5.0.0.
+  For existing projects, run `pod repo update` and `pod update ObjectBox` in the `ios` or `macos` directories.
+* Remove deprecated `contains` condition for `List<String>` properties, use `containsElement` instead.
 
 ## 4.3.1 (2025-09-02)
 

diff --git a/objectbox/example/flutter/objectbox_demo_relations/android/app/build.gradle b/objectbox/example/flutter/objectbox_demo_relations/android/app/build.gradle
@@ -83,5 +83,5 @@ dependencies {
     // Add the Android library with ObjectBox Admin only for debug builds.
     // Note: when the objectbox package updates, check if the Android
     // library below needs to be updated as well.
-    debugImplementation("io.objectbox:objectbox-android-objectbrowser:4.3.1")
+    debugImplementation("io.objectbox:objectbox-android-objectbrowser:5.0.1")
 }
diff --git a/objectbox/lib/src/native/bindings/bindings.dart b/objectbox/lib/src/native/bindings/bindings.dart
@@ -96,14 +96,14 @@ ObjectBoxC? _tryObjectBoxLibFile() {
 // libraries.
 // Library                 | C API | Database
 // ------------------------|-------|-----------------
-// C library 4.3.1         | 4.3.1 | 4.3.1-2025-07-28
-// Android library 4.3.1   | 4.3.1 | 4.3.1-2025-08-02
-// macOS/iOS library 4.4.1 | 4.3.1 | 4.3.1-2025-08-02
-var _obxCminMajor = 4;
-var _obxCminMinor = 3;
-var _obxCminPatch = 1;
+// C library 5.0.0-rc      | 5.0.0 | 5.0.0-2025-09-27
+// Android library 5.0.1   | 5.0.0 | 5.0.0-2025-09-27
+// macOS/iOS library 5.0.0 | 5.0.0 | 5.0.0-2025-09-27
+var _obxCminMajor = 5;
+var _obxCminMinor = 0;
+var _obxCminPatch = 0;
 // Require minimum database version guaranteeing actual C API availability.
-var _obxDatabaseMinVersion = "4.3.1-2025-07-28";
+var _obxDatabaseMinVersion = "5.0.0-2025-09-27";
 
 bool _isSupportedVersion(ObjectBoxC obxc) {
   // Require a minimum C API version

diff --git a/objectbox/lib/src/native/bindings/objectbox-sync.h b/objectbox/lib/src/native/bindings/objectbox-sync.h
@@ -34,7 +34,7 @@
 #include "objectbox.h"
 
 #if defined(static_assert) || defined(__cplusplus)
-static_assert(OBX_VERSION_MAJOR == 4 && OBX_VERSION_MINOR == 3 && OBX_VERSION_PATCH == 1,  // NOLINT
+static_assert(OBX_VERSION_MAJOR == 5 && OBX_VERSION_MINOR == 0 && OBX_VERSION_PATCH == 0,  // NOLINT
               "Versions of objectbox.h and objectbox-sync.h files do not match, please update");
 #endif
 
@@ -201,6 +201,20 @@ OBX_C_API OBX_sync* obx_sync_urls(OBX_store* store, const char* server_urls[], s
 /// Stops and closes (deletes) the sync client, freeing its resources.
 OBX_C_API obx_err obx_sync_close(OBX_sync* sync);
 
+/// Adds or replaces a sync filter variable value for the given name to the sync client.
+/// Eventually existing values for the same name are replaced.
+/// Client filter variables can be used in server-side sync filters to filter out objects that do not match the filter.
+/// Filter variables must be added before login, e.g. before obx_sync_start() or setting credentials.
+/// @param name non-NULL name of the filter variable
+/// @param value non-NULL value of the filter variable
+OBX_C_API obx_err obx_sync_filter_variables_put(OBX_sync* sync, const char* name, const char* value);
+
+/// Removes a previously added sync filter variable value.
+OBX_C_API obx_err obx_sync_filter_variables_remove(OBX_sync* sync, const char* name);
+
+/// Removes all previously added sync filter variable values.
+OBX_C_API obx_err obx_sync_filter_variables_remove_all(OBX_sync* sync);
+
 /// Sets credentials to authenticate the client with the server.
 /// Any credentials that were set before are replaced;
 /// if you want to pass multiple credentials, use obx_sync_credentials_add() instead.

diff --git a/objectbox/lib/src/native/bindings/objectbox.h b/objectbox/lib/src/native/bindings/objectbox.h
@@ -51,9 +51,9 @@ extern "C" {
 
 /// When using ObjectBox as a dynamic library, you should verify that a compatible version was linked using
 /// obx_version() or obx_version_is_at_least().
-#define OBX_VERSION_MAJOR 4
-#define OBX_VERSION_MINOR 3
-#define OBX_VERSION_PATCH 1  // values >= 100 are reserved for dev releases leading to the next minor/major increase
+#define OBX_VERSION_MAJOR 5
+#define OBX_VERSION_MINOR 0
+#define OBX_VERSION_PATCH 0  // values >= 100 are reserved for dev releases leading to the next minor/major increase
 
 //----------------------------------------------
 // Common types
@@ -179,6 +179,8 @@ typedef enum {
     /// This is a free trial version; only applies to server builds (no trial builds for database and Sync clients).
     OBXFeature_Trial = 18,
 
+    /// Server-side filters to return individual data for each sync user (user-specific data).
+    OBXFeature_SyncFilters = 19,
 
 } OBXFeature;
 
@@ -2121,7 +2123,7 @@ OBX_C_API obx_qb_cond obx_qb_less_or_equal_string(OBX_query_builder* builder, ob
 OBX_C_API obx_qb_cond obx_qb_in_strings(OBX_query_builder* builder, obx_schema_id property_id,
                                         const char* const values[], size_t count, bool case_sensitive);
 
-/// For OBXPropertyType_StringVector - matches if at least one vector item equals the given value.
+/// @deprecated Please use obx_qb_contains_element_string() instead.
 OBX_C_API obx_qb_cond obx_qb_any_equals_string(OBX_query_builder* builder, obx_schema_id property_id, const char* value,
                                                bool case_sensitive);
 

diff --git a/objectbox/lib/src/native/bindings/objectbox_c.dart b/objectbox/lib/src/native/bindings/objectbox_c.dart
@@ -4935,7 +4935,7 @@ class ObjectBoxC {
       int Function(ffi.Pointer<OBX_query_builder>, int,
           ffi.Pointer<ffi.Pointer<ffi.Char>>, int, bool)>();
 
-  /// For OBXPropertyType_StringVector - matches if at least one vector item equals the given value.
+  /// @deprecated Please use obx_qb_contains_element_string() instead.
   int qb_any_equals_string(
     ffi.Pointer<OBX_query_builder> builder,
     int property_id,
@@ -8399,6 +8399,67 @@ class ObjectBoxC {
   late final _sync_close =
       _sync_closePtr.asFunction<int Function(ffi.Pointer<OBX_sync>)>();
 
+  /// Adds or replaces a sync filter variable value for the given name to the sync client.
+  /// Eventually existing values for the same name are replaced.
+  /// Client filter variables can be used in server-side sync filters to filter out objects that do not match the filter.
+  /// Filter variables must be added before login, e.g. before obx_sync_start() or setting credentials.
+  /// @param name non-NULL name of the filter variable
+  /// @param value non-NULL value of the filter variable
+  int sync_filter_variables_put(
+    ffi.Pointer<OBX_sync> sync1,
+    ffi.Pointer<ffi.Char> name,
+    ffi.Pointer<ffi.Char> value,
+  ) {
+    return _sync_filter_variables_put(
+      sync1,
+      name,
+      value,
+    );
+  }
+
+  late final _sync_filter_variables_putPtr = _lookup<
+      ffi.NativeFunction<
+          obx_err Function(ffi.Pointer<OBX_sync>, ffi.Pointer<ffi.Char>,
+              ffi.Pointer<ffi.Char>)>>('obx_sync_filter_variables_put');
+  late final _sync_filter_variables_put =
+      _sync_filter_variables_putPtr.asFunction<
+          int Function(ffi.Pointer<OBX_sync>, ffi.Pointer<ffi.Char>,
+              ffi.Pointer<ffi.Char>)>();
+
+  /// Removes a previously added sync filter variable value.
+  int sync_filter_variables_remove(
+    ffi.Pointer<OBX_sync> sync1,
+    ffi.Pointer<ffi.Char> name,
+  ) {
+    return _sync_filter_variables_remove(
+      sync1,
+      name,
+    );
+  }
+
+  late final _sync_filter_variables_removePtr = _lookup<
+      ffi.NativeFunction<
+          obx_err Function(ffi.Pointer<OBX_sync>,
+              ffi.Pointer<ffi.Char>)>>('obx_sync_filter_variables_remove');
+  late final _sync_filter_variables_remove = _sync_filter_variables_removePtr
+      .asFunction<int Function(ffi.Pointer<OBX_sync>, ffi.Pointer<ffi.Char>)>();
+
+  /// Removes all previously added sync filter variable values.
+  int sync_filter_variables_remove_all(
+    ffi.Pointer<OBX_sync> sync1,
+  ) {
+    return _sync_filter_variables_remove_all(
+      sync1,
+    );
+  }
+
+  late final _sync_filter_variables_remove_allPtr =
+      _lookup<ffi.NativeFunction<obx_err Function(ffi.Pointer<OBX_sync>)>>(
+          'obx_sync_filter_variables_remove_all');
+  late final _sync_filter_variables_remove_all =
+      _sync_filter_variables_remove_allPtr
+          .asFunction<int Function(ffi.Pointer<OBX_sync>)>();
+
   /// Sets credentials to authenticate the client with the server.
   /// Any credentials that were set before are replaced;
   /// if you want to pass multiple credentials, use obx_sync_credentials_add() instead.
@@ -10400,6 +10461,9 @@ abstract class OBXFeature {
 
   /// This is a free trial version; only applies to server builds (no trial builds for database and Sync clients).
   static const int Trial = 18;
+
+  /// Server-side filters to return individual data for each sync user (user-specific data).
+  static const int SyncFilters = 19;
 }
 
 /// Log level as passed to obx_log_callback.
@@ -11677,11 +11741,11 @@ class OBX_dart_finalizer extends ffi.Opaque {}
 typedef obx_dart_closer
     = ffi.NativeFunction<obx_err Function(ffi.Pointer<ffi.Void> native_object)>;
 
-const int OBX_VERSION_MAJOR = 4;
+const int OBX_VERSION_MAJOR = 5;
 
-const int OBX_VERSION_MINOR = 3;
+const int OBX_VERSION_MINOR = 0;
 
-const int OBX_VERSION_PATCH = 1;
+const int OBX_VERSION_PATCH = 0;
 
 const int OBX_ID_NEW = -1;
 

diff --git a/objectbox/lib/src/native/query/query.dart b/objectbox/lib/src/native/query/query.dart
@@ -433,11 +433,6 @@ class QueryStringVectorProperty<EntityT>
     extends QueryProperty<EntityT, List<String>> {
   QueryStringVectorProperty(super.model);
 
-  @Deprecated(
-      'Use `containsElement` instead. Will be removed in a future release.')
-  Condition<EntityT> contains(String p, {bool? caseSensitive, String? alias}) =>
-      containsElement(p, caseSensitive: caseSensitive, alias: alias);
-
   /// Matches if at least one element of the list equals the given value.
   Condition<EntityT> containsElement(String value,
           {bool? caseSensitive, String? alias}) =>