diff --git a/flutter/sherpa_onnx/lib/src/audio_tagging.dart b/flutter/sherpa_onnx/lib/src/audio_tagging.dart
index 6c650b30c..3e3dbed2f 100644
--- a/flutter/sherpa_onnx/lib/src/audio_tagging.dart
+++ b/flutter/sherpa_onnx/lib/src/audio_tagging.dart
@@ -62,6 +62,8 @@ class AudioEvent {
 }
 
 class AudioTagging {
+  AudioTagging.fromPtr({required this.ptr, required this.config});
+
   AudioTagging._({required this.ptr, required this.config});
 
   // The user has to invoke AudioTagging.free() to avoid memory leak.
diff --git a/flutter/sherpa_onnx/lib/src/keyword_spotter.dart b/flutter/sherpa_onnx/lib/src/keyword_spotter.dart
index c09867995..6e2c669ae 100644
--- a/flutter/sherpa_onnx/lib/src/keyword_spotter.dart
+++ b/flutter/sherpa_onnx/lib/src/keyword_spotter.dart
@@ -53,6 +53,8 @@ class KeywordResult {
 }
 
 class KeywordSpotter {
+  KeywordSpotter.fromPtr({required this.ptr, required this.config});
+
   KeywordSpotter._({required this.ptr, required this.config});
 
   /// The user is responsible to call the OnlineRecognizer.free()
diff --git a/flutter/sherpa_onnx/lib/src/offline_recognizer.dart b/flutter/sherpa_onnx/lib/src/offline_recognizer.dart
index 2f6f167d4..01bceccce 100644
--- a/flutter/sherpa_onnx/lib/src/offline_recognizer.dart
+++ b/flutter/sherpa_onnx/lib/src/offline_recognizer.dart
@@ -227,6 +227,8 @@ class OfflineRecognizerResult {
 }
 
 class OfflineRecognizer {
+  OfflineRecognizer.fromPtr({required this.ptr, required this.config});
+
   OfflineRecognizer._({required this.ptr, required this.config});
 
   void free() {
diff --git a/flutter/sherpa_onnx/lib/src/offline_speaker_diarization.dart b/flutter/sherpa_onnx/lib/src/offline_speaker_diarization.dart
index 5981e3c04..fe046a166 100644
--- a/flutter/sherpa_onnx/lib/src/offline_speaker_diarization.dart
+++ b/flutter/sherpa_onnx/lib/src/offline_speaker_diarization.dart
@@ -94,6 +94,9 @@ class OfflineSpeakerDiarizationConfig {
 }
 
 class OfflineSpeakerDiarization {
+  OfflineSpeakerDiarization.fromPtr(
+      {required this.ptr, required this.config, required this.sampleRate});
+
   OfflineSpeakerDiarization._(
       {required this.ptr, required this.config, required this.sampleRate});
 
diff --git a/flutter/sherpa_onnx/lib/src/online_recognizer.dart b/flutter/sherpa_onnx/lib/src/online_recognizer.dart
index 18d5a6000..69ed93894 100644
--- a/flutter/sherpa_onnx/lib/src/online_recognizer.dart
+++ b/flutter/sherpa_onnx/lib/src/online_recognizer.dart
@@ -162,6 +162,8 @@ class OnlineRecognizerResult {
 }
 
 class OnlineRecognizer {
+  OnlineRecognizer.fromPtr({required this.ptr, required this.config});
+
   OnlineRecognizer._({required this.ptr, required this.config});
 
   /// The user is responsible to call the OnlineRecognizer.free()
diff --git a/flutter/sherpa_onnx/lib/src/punctuation.dart b/flutter/sherpa_onnx/lib/src/punctuation.dart
index b4197fa46..dd38a2445 100644
--- a/flutter/sherpa_onnx/lib/src/punctuation.dart
+++ b/flutter/sherpa_onnx/lib/src/punctuation.dart
@@ -36,6 +36,8 @@ class OfflinePunctuationConfig {
 }
 
 class OfflinePunctuation {
+  OfflinePunctuation.fromPtr({required this.ptr, required this.config});
+
   OfflinePunctuation._({required this.ptr, required this.config});
 
   // The user has to invoke OfflinePunctuation.free() to avoid memory leak.
diff --git a/flutter/sherpa_onnx/lib/src/speaker_identification.dart b/flutter/sherpa_onnx/lib/src/speaker_identification.dart
index 5c2e10744..8b27dbc69 100644
--- a/flutter/sherpa_onnx/lib/src/speaker_identification.dart
+++ b/flutter/sherpa_onnx/lib/src/speaker_identification.dart
@@ -25,6 +25,8 @@ class SpeakerEmbeddingExtractorConfig {
 }
 
 class SpeakerEmbeddingExtractor {
+  SpeakerEmbeddingExtractor.fromPtr({required this.ptr, required this.dim});
+
   SpeakerEmbeddingExtractor._({required this.ptr, required this.dim});
 
   /// The user is responsible to call the SpeakerEmbeddingExtractor.free()
@@ -101,6 +103,8 @@ class SpeakerEmbeddingExtractor {
 }
 
 class SpeakerEmbeddingManager {
+  SpeakerEmbeddingManager.fromPtr({required this.ptr, required this.dim});
+
   SpeakerEmbeddingManager._({required this.ptr, required this.dim});
 
   // The user has to use SpeakerEmbeddingManager.free() to avoid memory leak
diff --git a/flutter/sherpa_onnx/lib/src/tts.dart b/flutter/sherpa_onnx/lib/src/tts.dart
index f779188b7..2f550e273 100644
--- a/flutter/sherpa_onnx/lib/src/tts.dart
+++ b/flutter/sherpa_onnx/lib/src/tts.dart
@@ -82,6 +82,8 @@ class GeneratedAudio {
 }
 
 class OfflineTts {
+  OfflineTts.fromPtr({required this.ptr, required this.config});
+
   OfflineTts._({required this.ptr, required this.config});
 
   /// The user is responsible to call the OfflineTts.free()
diff --git a/flutter/sherpa_onnx/lib/src/vad.dart b/flutter/sherpa_onnx/lib/src/vad.dart
index 10fac5a45..7db0e55e0 100644
--- a/flutter/sherpa_onnx/lib/src/vad.dart
+++ b/flutter/sherpa_onnx/lib/src/vad.dart
@@ -54,6 +54,8 @@ class SpeechSegment {
 }
 
 class CircularBuffer {
+  CircularBuffer.fromPtr({required this.ptr});
+
   CircularBuffer._({required this.ptr});
 
   /// The user has to invoke CircularBuffer.free() on the returned instance
@@ -115,6 +117,8 @@ class CircularBuffer {
 }
 
 class VoiceActivityDetector {
+  VoiceActivityDetector.fromPtr({required this.ptr, required this.config});
+
   VoiceActivityDetector._({required this.ptr, required this.config});
 
   // The user has to invoke VoiceActivityDetector.free() to avoid memory leak.