diff --git a/.github/workflows/test-dot-net-nuget.yaml b/.github/workflows/test-dot-net-nuget.yaml
index b162e2b1..6a40a7e8 100644
--- a/.github/workflows/test-dot-net-nuget.yaml
+++ b/.github/workflows/test-dot-net-nuget.yaml
@@ -53,6 +53,7 @@ jobs:
           ./run-nemo-ctc.sh
           ./run-paraformer.sh
           ./run-zipformer.sh
+          ./run-hotwords.sh
           ./run-whisper.sh
           ./run-tdnn-yesno.sh
 
diff --git a/.github/workflows/test-dot-net.yaml b/.github/workflows/test-dot-net.yaml
index 6a133add..b3d7d8f7 100644
--- a/.github/workflows/test-dot-net.yaml
+++ b/.github/workflows/test-dot-net.yaml
@@ -194,6 +194,7 @@ jobs:
           ./run-nemo-ctc.sh
           ./run-paraformer.sh
           ./run-zipformer.sh
+          ./run-hotwords.sh
           ./run-whisper.sh
           ./run-tdnn-yesno.sh
 
diff --git a/dotnet-examples/offline-decode-files/run-hotwords.sh b/dotnet-examples/offline-decode-files/run-hotwords.sh
new file mode 100755
index 00000000..bfa1dfc0
--- /dev/null
+++ b/dotnet-examples/offline-decode-files/run-hotwords.sh
@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+set -ex
+
+if [ ! -d ./sherpa-onnx-zipformer-en-2023-04-01 ]; then
+  wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
+  tar xvf sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
+  rm sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
+fi
+
+if [ ! -f ./sherpa-onnx-zipformer-en-2023-04-01/hotwords_en.txt ]; then
+cat >./sherpa-onnx-zipformer-en-2023-04-01/hotwords_en.txt <<EOF
+▁ QUA R TER S
+▁FOR E VER
+EOF
+fi
+
+dotnet run \
+  --tokens=./sherpa-onnx-zipformer-en-2023-04-01/tokens.txt \
+  --encoder=./sherpa-onnx-zipformer-en-2023-04-01/encoder-epoch-99-avg-1.onnx \
+  --decoder=./sherpa-onnx-zipformer-en-2023-04-01/decoder-epoch-99-avg-1.onnx \
+  --joiner=./sherpa-onnx-zipformer-en-2023-04-01/joiner-epoch-99-avg-1.onnx \
+  --num-threads=2 \
+  --decoding-method=modified_beam_search \
+  --files ./sherpa-onnx-zipformer-en-2023-04-01/test_wavs/0.wav \
+  ./sherpa-onnx-zipformer-en-2023-04-01/test_wavs/1.wav
+
+dotnet run \
+  --hotwords-file=./sherpa-onnx-zipformer-en-2023-04-01/hotwords_en.txt \
+  --hotwords-score=2.0 \
+  --tokens=./sherpa-onnx-zipformer-en-2023-04-01/tokens.txt \
+  --encoder=./sherpa-onnx-zipformer-en-2023-04-01/encoder-epoch-99-avg-1.onnx \
+  --decoder=./sherpa-onnx-zipformer-en-2023-04-01/decoder-epoch-99-avg-1.onnx \
+  --joiner=./sherpa-onnx-zipformer-en-2023-04-01/joiner-epoch-99-avg-1.onnx \
+  --num-threads=2 \
+  --decoding-method=modified_beam_search \
+  --files ./sherpa-onnx-zipformer-en-2023-04-01/test_wavs/0.wav \
+  ./sherpa-onnx-zipformer-en-2023-04-01/test_wavs/1.wav
+
+# 0.wav: QUARTER -> QUARTERS
+# 1.wav: FOR EVER -> FOREVER
diff --git a/dotnet-examples/offline-decode-files/run-nemo-ctc.sh b/dotnet-examples/offline-decode-files/run-nemo-ctc.sh
index dcfcf4f4..44e4ee0b 100755
--- a/dotnet-examples/offline-decode-files/run-nemo-ctc.sh
+++ b/dotnet-examples/offline-decode-files/run-nemo-ctc.sh
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+set -ex
+
 if [ ! -d ./sherpa-onnx-nemo-ctc-en-conformer-medium ]; then
   GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/sherpa-onnx-nemo-ctc-en-conformer-medium
   cd sherpa-onnx-nemo-ctc-en-conformer-medium
diff --git a/dotnet-examples/offline-decode-files/run-paraformer.sh b/dotnet-examples/offline-decode-files/run-paraformer.sh
index 9dff4574..4fb72f41 100755
--- a/dotnet-examples/offline-decode-files/run-paraformer.sh
+++ b/dotnet-examples/offline-decode-files/run-paraformer.sh
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+set -ex
+
 if [ ! -d ./sherpa-onnx-paraformer-zh-2023-03-28 ]; then
   GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/sherpa-onnx-paraformer-zh-2023-03-28
   cd sherpa-onnx-paraformer-zh-2023-03-28
diff --git a/dotnet-examples/offline-decode-files/run-tdnn-yesno.sh b/dotnet-examples/offline-decode-files/run-tdnn-yesno.sh
index 32d4a487..c2d8e9fd 100755
--- a/dotnet-examples/offline-decode-files/run-tdnn-yesno.sh
+++ b/dotnet-examples/offline-decode-files/run-tdnn-yesno.sh
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+set -ex
+
 if [ ! -d ./sherpa-onnx-tdnn-yesno ]; then
   GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/sherpa-onnx-tdnn-yesno
   cd sherpa-onnx-tdnn-yesno
diff --git a/dotnet-examples/offline-decode-files/run-whisper.sh b/dotnet-examples/offline-decode-files/run-whisper.sh
index 8ac45282..6f5e26c6 100755
--- a/dotnet-examples/offline-decode-files/run-whisper.sh
+++ b/dotnet-examples/offline-decode-files/run-whisper.sh
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+set -ex
+
 if [ ! -d ./sherpa-onnx-whisper-tiny.en ]; then
   GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/sherpa-onnx-whisper-tiny.en
   cd sherpa-onnx-whisper-tiny.en
diff --git a/dotnet-examples/offline-decode-files/run-zipformer.sh b/dotnet-examples/offline-decode-files/run-zipformer.sh
index 0bfb3641..6844307d 100755
--- a/dotnet-examples/offline-decode-files/run-zipformer.sh
+++ b/dotnet-examples/offline-decode-files/run-zipformer.sh
@@ -1,10 +1,11 @@
 #!/usr/bin/env bash
-#
+
+set -ex
+
 if [ ! -d ./sherpa-onnx-zipformer-en-2023-04-01 ]; then
-  GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/sherpa-onnx-zipformer-en-2023-04-01
-  cd sherpa-onnx-zipformer-en-2023-04-01
-  git lfs pull --include "*.onnx"
-  cd ..
+  wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
+  tar xvf sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
+  rm sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
 fi
 
 dotnet run \
diff --git a/dotnet-examples/offline-tts-play/run-piper.sh b/dotnet-examples/offline-tts-play/run-piper.sh
new file mode 100755
index 00000000..ff639c57
--- /dev/null
+++ b/dotnet-examples/offline-tts-play/run-piper.sh
@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+set -ex
+if [ ! -f ./vits-piper-en_US-amy-low/en_US-amy-low.onnx ]; then
+  # wget -qq https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-en_US-amy-low.tar.bz2
+  curl -OL https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-en_US-amy-low.tar.bz2
+  tar xf vits-piper-en_US-amy-low.tar.bz2
+  rm vits-piper-en_US-amy-low.tar.bz2
+fi
+
+dotnet run \
+  --vits-model=./vits-piper-en_US-amy-low/en_US-amy-low.onnx \
+  --vits-tokens=./vits-piper-en_US-amy-low/tokens.txt \
+  --vits-data-dir=./vits-piper-en_US-amy-low/espeak-ng-data \
+  --debug=1 \
+  --output-filename=./amy.wav \
+  --text="This is a text to speech application in dotnet with Next Generation Kaldi"
+
diff --git a/dotnet-examples/offline-tts/run-aishell3.sh b/dotnet-examples/offline-tts/run-aishell3.sh
index 7e5cc639..44e5e261 100755
--- a/dotnet-examples/offline-tts/run-aishell3.sh
+++ b/dotnet-examples/offline-tts/run-aishell3.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-
+set -ex
 if [ ! -f ./vits-zh-aishell3/vits-aishell3.onnx ]; then
   # wget -qq https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-zh-aishell3.tar.bz2
   curl -OL https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-zh-aishell3.tar.bz2
diff --git a/dotnet-examples/offline-tts/run-piper.sh b/dotnet-examples/offline-tts/run-piper.sh
index a2674091..ff639c57 100755
--- a/dotnet-examples/offline-tts/run-piper.sh
+++ b/dotnet-examples/offline-tts/run-piper.sh
@@ -1,5 +1,6 @@
 #!/usr/bin/env bash
 
+set -ex
 if [ ! -f ./vits-piper-en_US-amy-low/en_US-amy-low.onnx ]; then
   # wget -qq https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-en_US-amy-low.tar.bz2
   curl -OL https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-en_US-amy-low.tar.bz2
diff --git a/dotnet-examples/online-decode-files/run-paraformer.sh b/dotnet-examples/online-decode-files/run-paraformer.sh
index 4200aee7..5731d013 100755
--- a/dotnet-examples/online-decode-files/run-paraformer.sh
+++ b/dotnet-examples/online-decode-files/run-paraformer.sh
@@ -4,6 +4,7 @@
 # https://k2-fsa.github.io/sherpa/onnx/pretrained_models/online-paraformer/paraformer-models.html#csukuangfj-sherpa-onnx-streaming-paraformer-bilingual-zh-en-chinese-english
 # to download the model files
 
+set -ex
 if [ ! -d ./sherpa-onnx-streaming-paraformer-bilingual-zh-en ]; then
   GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/sherpa-onnx-streaming-paraformer-bilingual-zh-en
   cd sherpa-onnx-streaming-paraformer-bilingual-zh-en
diff --git a/dotnet-examples/online-decode-files/run-transducer.sh b/dotnet-examples/online-decode-files/run-transducer.sh
index 4023f1ad..06c478ba 100755
--- a/dotnet-examples/online-decode-files/run-transducer.sh
+++ b/dotnet-examples/online-decode-files/run-transducer.sh
@@ -4,6 +4,7 @@
 # https://k2-fsa.github.io/sherpa/onnx/pretrained_models/online-transducer/zipformer-transducer-models.html#csukuangfj-sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20-bilingual-chinese-english
 # to download the model files
 
+set -ex
 if [ ! -d ./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20 ]; then
   GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20
   cd sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20
diff --git a/dotnet-examples/online-decode-files/run-zipformer2-ctc.sh b/dotnet-examples/online-decode-files/run-zipformer2-ctc.sh
index 910b27f3..cfc0eb55 100755
--- a/dotnet-examples/online-decode-files/run-zipformer2-ctc.sh
+++ b/dotnet-examples/online-decode-files/run-zipformer2-ctc.sh
@@ -4,6 +4,7 @@
 # https://k2-fsa.github.io/sherpa/onnx/pretrained_models/online-ctc/zipformer-ctc-models.html#sherpa-onnx-streaming-zipformer-ctc-multi-zh-hans-2023-12-13-chinese
 # to download the model files
 
+set -ex
 if [ ! -d ./sherpa-onnx-streaming-zipformer-ctc-multi-zh-hans-2023-12-13 ]; then
   curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-streaming-zipformer-ctc-multi-zh-hans-2023-12-13.tar.bz2
   tar xvf sherpa-onnx-streaming-zipformer-ctc-multi-zh-hans-2023-12-13.tar.bz2
diff --git a/dotnet-examples/speech-recognition-from-microphone/run-paraformer.sh b/dotnet-examples/speech-recognition-from-microphone/run-paraformer.sh
index 5e774a55..ec4e15d7 100755
--- a/dotnet-examples/speech-recognition-from-microphone/run-paraformer.sh
+++ b/dotnet-examples/speech-recognition-from-microphone/run-paraformer.sh
@@ -4,6 +4,7 @@
 # https://k2-fsa.github.io/sherpa/onnx/pretrained_models/online-paraformer/paraformer-models.html#csukuangfj-sherpa-onnx-streaming-paraformer-bilingual-zh-en-chinese-english
 # to download the model files
 
+set -ex
 if [ ! -d ./sherpa-onnx-streaming-paraformer-bilingual-zh-en ]; then
   GIT_LFS_SKIP_SMUDGE=1 git clone https://huggingface.co/csukuangfj/sherpa-onnx-streaming-paraformer-bilingual-zh-en
   cd sherpa-onnx-streaming-paraformer-bilingual-zh-en
diff --git a/dotnet-examples/speech-recognition-from-microphone/run-transducer.sh b/dotnet-examples/speech-recognition-from-microphone/run-transducer.sh
index 7d5fe0b5..1c1dc11a 100755
--- a/dotnet-examples/speech-recognition-from-microphone/run-transducer.sh
+++ b/dotnet-examples/speech-recognition-from-microphone/run-transducer.sh
@@ -4,6 +4,8 @@
 # https://k2-fsa.github.io/sherpa/onnx/pretrained_models/online-transducer/zipformer-transducer-models.html#csukuangfj-sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20-bilingual-chinese-english
 # to download the model files
 #
+set -ex
+
 export LD_LIBRARY_PATH=$PWD:$LD_LIBRARY_PATH
 export DYLD_LIBRARY_PATH=$PWD:$DYLD_LIBRARY_PATH