diff --git a/sherpa-onnx/c-api/c-api.cc b/sherpa-onnx/c-api/c-api.cc
index 4a11cae29..099401d2a 100644
--- a/sherpa-onnx/c-api/c-api.cc
+++ b/sherpa-onnx/c-api/c-api.cc
@@ -24,6 +24,7 @@
 #include "sherpa-onnx/csrc/macros.h"
 #include "sherpa-onnx/csrc/offline-punctuation.h"
 #include "sherpa-onnx/csrc/offline-recognizer.h"
+#include "sherpa-onnx/csrc/online-punctuation.h"
 #include "sherpa-onnx/csrc/online-recognizer.h"
 #include "sherpa-onnx/csrc/resample.h"
 #include "sherpa-onnx/csrc/speaker-embedding-extractor.h"
@@ -1717,6 +1718,53 @@ const char *SherpaOfflinePunctuationAddPunct(
 
 void SherpaOfflinePunctuationFreeText(const char *text) { delete[] text; }
 
+struct SherpaOnnxOnlinePunctuation {
+  std::unique_ptr<sherpa_onnx::OnlinePunctuation> impl;
+};
+
+const SherpaOnnxOnlinePunctuation *SherpaOnnxCreateOnlinePunctuation(
+    const SherpaOnnxOnlinePunctuationConfig *config) {
+  auto p = new SherpaOnnxOnlinePunctuation;
+  try {
+    sherpa_onnx::OnlinePunctuationConfig punctuation_config;
+    punctuation_config.model.cnn_bilstm = config->model.cnn_bilstm;
+    punctuation_config.model.bpe_vocab = config->model.bpe_vocab;
+    punctuation_config.model.num_threads = config->model.num_threads;
+    punctuation_config.model.debug = config->model.debug;
+    punctuation_config.model.provider = config->model.provider;
+
+    p->impl =
+        std::make_unique<sherpa_onnx::OnlinePunctuation>(punctuation_config);
+  } catch (const std::exception &e) {
+    SHERPA_ONNX_LOGE("Failed to create online punctuation: %s", e.what());
+    delete p;
+    return nullptr;
+  }
+  return p;
+}
+
+void SherpaOnnxDestroyOnlinePunctuation(const SherpaOnnxOnlinePunctuation *p) {
+  delete p;
+}
+
+const char *SherpaOnnxOnlinePunctuationAddPunct(
+    const SherpaOnnxOnlinePunctuation *punctuation, const char *text) {
+  if (!punctuation || !text) return nullptr;
+
+  try {
+    std::string s = punctuation->impl->AddPunctuationWithCase(text);
+    char *p = new char[s.size() + 1];
+    std::copy(s.begin(), s.end(), p);
+    p[s.size()] = '\0';
+    return p;
+  } catch (const std::exception &e) {
+    SHERPA_ONNX_LOGE("Failed to add punctuation: %s", e.what());
+    return nullptr;
+  }
+}
+
+void SherpaOnnxOnlinePunctuationFreeText(const char *text) { delete[] text; }
+
 struct SherpaOnnxLinearResampler {
   std::unique_ptr<sherpa_onnx::LinearResample> impl;
 };
diff --git a/sherpa-onnx/c-api/c-api.h b/sherpa-onnx/c-api/c-api.h
index 4d4a2c4fc..990c94cb3 100644
--- a/sherpa-onnx/c-api/c-api.h
+++ b/sherpa-onnx/c-api/c-api.h
@@ -1369,6 +1369,39 @@ SHERPA_ONNX_API const char *SherpaOfflinePunctuationAddPunct(
 
 SHERPA_ONNX_API void SherpaOfflinePunctuationFreeText(const char *text);
 
+SHERPA_ONNX_API typedef struct SherpaOnnxOnlinePunctuationModelConfig {
+  const char *cnn_bilstm;
+  const char *bpe_vocab;
+  int32_t num_threads;
+  int32_t debug;
+  const char *provider;
+} SherpaOnnxOnlinePunctuationModelConfig;
+
+SHERPA_ONNX_API typedef struct SherpaOnnxOnlinePunctuationConfig {
+  SherpaOnnxOnlinePunctuationModelConfig model;
+} SherpaOnnxOnlinePunctuationConfig;
+
+SHERPA_ONNX_API typedef struct SherpaOnnxOnlinePunctuation SherpaOnnxOnlinePunctuation;
+
+// Create an online punctuation processor. The user has to invoke
+// SherpaOnnxDestroyOnlinePunctuation() to free the returned pointer
+// to avoid memory leak
+SHERPA_ONNX_API const SherpaOnnxOnlinePunctuation *SherpaOnnxCreateOnlinePunctuation(
+    const SherpaOnnxOnlinePunctuationConfig *config);
+
+// Free a pointer returned by SherpaOnnxCreateOnlinePunctuation()
+SHERPA_ONNX_API void SherpaOnnxDestroyOnlinePunctuation(
+    const SherpaOnnxOnlinePunctuation *punctuation);
+
+// Add punctuations to the input text. The user has to invoke
+// SherpaOnnxOnlinePunctuationFreeText() to free the returned pointer
+// to avoid memory leak
+SHERPA_ONNX_API const char *SherpaOnnxOnlinePunctuationAddPunct(
+    const SherpaOnnxOnlinePunctuation *punctuation, const char *text);
+
+// Free a pointer returned by SherpaOnnxOnlinePunctuationAddPunct()
+SHERPA_ONNX_API void SherpaOnnxOnlinePunctuationFreeText(const char *text);
+
 // for resampling
 SHERPA_ONNX_API typedef struct SherpaOnnxLinearResampler
     SherpaOnnxLinearResampler;
diff --git a/swift-api-examples/SherpaOnnx.swift b/swift-api-examples/SherpaOnnx.swift
index 661ebba28..b100ef408 100644
--- a/swift-api-examples/SherpaOnnx.swift
+++ b/swift-api-examples/SherpaOnnx.swift
@@ -1095,6 +1095,52 @@ class SherpaOnnxOfflinePunctuationWrapper {
   }
 }
 
+func sherpaOnnxOnlinePunctuationModelConfig(
+  cnnBiLstm: String,
+  bpeVocab: String,
+  numThreads: Int = 1,
+  debug: Int = 0,
+  provider: String = "cpu"
+) -> SherpaOnnxOnlinePunctuationModelConfig {
+  return SherpaOnnxOnlinePunctuationModelConfig(
+    cnn_bilstm: toCPointer(cnnBiLstm),
+    bpe_vocab: toCPointer(bpeVocab),
+    num_threads: Int32(numThreads),
+    debug: Int32(debug),
+    provider: toCPointer(provider))
+}
+
+func sherpaOnnxOnlinePunctuationConfig(
+  model: SherpaOnnxOnlinePunctuationModelConfig
+) -> SherpaOnnxOnlinePunctuationConfig {
+  return SherpaOnnxOnlinePunctuationConfig(model: model)
+}
+
+class SherpaOnnxOnlinePunctuationWrapper {
+  /// A pointer to the underlying counterpart in C
+  let ptr: OpaquePointer!
+
+  /// Constructor taking a model config
+  init(
+    config: UnsafePointer<SherpaOnnxOnlinePunctuationConfig>!
+  ) {
+    ptr = SherpaOnnxCreateOnlinePunctuation(config)
+  }
+
+  deinit {
+    if let ptr {
+      SherpaOnnxDestroyOnlinePunctuation(ptr)
+    }
+  }
+
+  func addPunct(text: String) -> String {
+    let cText = SherpaOnnxOnlinePunctuationAddPunct(ptr, toCPointer(text))
+    let ans = String(cString: cText!)
+    SherpaOnnxOnlinePunctuationFreeText(cText)
+    return ans
+  }
+}
+
 func sherpaOnnxOfflineSpeakerSegmentationPyannoteModelConfig(model: String)
   -> SherpaOnnxOfflineSpeakerSegmentationPyannoteModelConfig
 {
diff --git a/swift-api-examples/add-punctuation-online.swift b/swift-api-examples/add-punctuation-online.swift
new file mode 100644
index 000000000..79af921eb
--- /dev/null
+++ b/swift-api-examples/add-punctuation-online.swift
@@ -0,0 +1,35 @@
+func run() {
+    let model = "./sherpa-onnx-online-punct-en-2024-08-06/model.onnx"
+    let bpe = "./sherpa-onnx-online-punct-en-2024-08-06/bpe.vocab"
+    
+    // Create model config
+    let modelConfig = sherpaOnnxOnlinePunctuationModelConfig(
+        cnnBiLstm: model,
+        bpeVocab: bpe
+    )
+    
+    // Create punctuation config
+    var config = sherpaOnnxOnlinePunctuationConfig(model: modelConfig)
+    
+    // Create punctuation instance
+    let punct = SherpaOnnxOnlinePunctuationWrapper(config: &config)
+    
+    // Test texts
+    let textList = [
+        "how are you i am fine thank you",
+        "The African blogosphere is rapidly expanding bringing more voices online in the form of commentaries opinions analyses rants and poetry"
+    ]
+    
+    // Process each text
+  for i in 0..<textList.count {
+    let t = punct.addPunct(text: textList[i])
+    print("\nresult is:\n\(t)")
+  }
+}
+
+@main
+struct App {
+  static func main() {
+    run()
+  }
+}
diff --git a/swift-api-examples/run-add-punctuations-online.sh b/swift-api-examples/run-add-punctuations-online.sh
new file mode 100644
index 000000000..fe77c1aad
--- /dev/null
+++ b/swift-api-examples/run-add-punctuations-online.sh
@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+set -ex
+
+if [ ! -d ../build-swift-macos ]; then
+  echo "Please run ../build-swift-macos.sh first!"
+  exit 1
+fi
+
+# Download and extract the online punctuation model if not exists
+if [ ! -d ./sherpa-onnx-online-punct-en-2024-08-06 ]; then
+  curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/punctuation-models/sherpa-onnx-online-punct-en-2024-08-06.tar.bz2
+  tar xvf sherpa-onnx-online-punct-en-2024-08-06.tar.bz2
+  rm sherpa-onnx-online-punct-en-2024-08-06.tar.bz2
+fi
+
+if [ ! -e ./add-punctuation-online ]; then
+  # Note: We use -lc++ to link against libc++ instead of libstdc++
+  swiftc \
+    -lc++ \
+    -I ../build-swift-macos/install/include \
+    -import-objc-header ./SherpaOnnx-Bridging-Header.h \
+    ./add-punctuation-online.swift  ./SherpaOnnx.swift \
+    -L ../build-swift-macos/install/lib/ \
+    -l sherpa-onnx \
+    -l onnxruntime \
+    -o ./add-punctuation-online
+
+  strip ./add-punctuation-online
+else
+  echo "./add-punctuation-online exists - skip building"
+fi
+
+# Set library path and run the executable
+export DYLD_LIBRARY_PATH=$PWD/../build-swift-macos/install/lib:$DYLD_LIBRARY_PATH
+./add-punctuation-online 
\ No newline at end of file