diff --git a/.github/scripts/test-python.sh b/.github/scripts/test-python.sh
index c03b95426..0dbb8b99d 100755
--- a/.github/scripts/test-python.sh
+++ b/.github/scripts/test-python.sh
@@ -256,7 +256,18 @@ if [[ x$OS != x'windows-latest' ]]; then
     $repo/test_wavs/3.wav \
     $repo/test_wavs/8k.wav
 
+  ln -s $repo $PWD/
+
+  curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/itn_zh_number.fst
+  curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/itn-zh-number.wav
+
+  python3 ./python-api-examples/inverse-text-normalization-online-asr.py
+
   python3 sherpa-onnx/python/tests/test_online_recognizer.py --verbose
+
+  rm -rfv sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20
+
+  rm -rf $repo
 fi
 
 log "Test non-streaming transducer models"
diff --git a/python-api-examples/inverse-text-normalization-online-asr.py b/python-api-examples/inverse-text-normalization-online-asr.py
new file mode 100755
index 000000000..8524c20f3
--- /dev/null
+++ b/python-api-examples/inverse-text-normalization-online-asr.py
@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+#
+# Copyright (c)  2024  Xiaomi Corporation
+
+"""
+This script shows how to use inverse text normalization with streaming ASR.
+
+Usage:
+
+(1) Download the test model
+
+wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20.tar.bz2
+
+(2) Download rule fst
+
+wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/itn_zh_number.fst
+
+Please refer to
+https://github.com/k2-fsa/colab/blob/master/sherpa-onnx/itn_zh_number.ipynb
+for how itn_zh_number.fst is generated.
+
+(3) Download test wave
+
+wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/itn-zh-number.wav
+
+(4) Run this script
+
+python3 ./python-api-examples/inverse-text-normalization-online-asr.py
+"""
+from pathlib import Path
+
+import sherpa_onnx
+import soundfile as sf
+
+
+def create_recognizer():
+    encoder = "./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/encoder-epoch-99-avg-1.int8.onnx"
+    decoder = "./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/decoder-epoch-99-avg-1.onnx"
+    joiner = "./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/joiner-epoch-99-avg-1.int8.onnx"
+    tokens = "./sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/tokens.txt"
+    rule_fsts = "./itn_zh_number.fst"
+
+    if (
+        not Path(encoder).is_file()
+        or not Path(decoder).is_file()
+        or not Path(joiner).is_file()
+        or not Path(tokens).is_file()
+        or not Path(rule_fsts).is_file()
+    ):
+        raise ValueError(
+            """Please download model files from
+            https://github.com/k2-fsa/sherpa-onnx/releases/tag/asr-models
+            """
+        )
+    return sherpa_onnx.OnlineRecognizer.from_transducer(
+        encoder=encoder,
+        decoder=decoder,
+        joiner=joiner,
+        tokens=tokens,
+        debug=True,
+        rule_fsts=rule_fsts,
+    )
+
+
+def main():
+    recognizer = create_recognizer()
+    wave_filename = "./itn-zh-number.wav"
+    if not Path(wave_filename).is_file():
+        raise ValueError(
+            """Please download model files from
+            https://github.com/k2-fsa/sherpa-onnx/releases/tag/asr-models
+            """
+        )
+    audio, sample_rate = sf.read(wave_filename, dtype="float32", always_2d=True)
+    audio = audio[:, 0]  # only use the first channel
+
+    stream = recognizer.create_stream()
+    stream.accept_waveform(sample_rate, audio)
+
+    tail_padding = [0] * int(0.3 * sample_rate)
+    stream.accept_waveform(sample_rate, tail_padding)
+
+    while recognizer.is_ready(stream):
+        recognizer.decode_stream(stream)
+
+    print(wave_filename)
+    print(recognizer.get_result_all(stream))
+
+
+if __name__ == "__main__":
+    main()
diff --git a/sherpa-onnx/csrc/online-recognizer-ctc-impl.h b/sherpa-onnx/csrc/online-recognizer-ctc-impl.h
index 4d8ce2961..7dd9d8b18 100644
--- a/sherpa-onnx/csrc/online-recognizer-ctc-impl.h
+++ b/sherpa-onnx/csrc/online-recognizer-ctc-impl.h
@@ -68,7 +68,8 @@ static OnlineRecognizerResult Convert(const OnlineCtcDecoderResult &src,
 class OnlineRecognizerCtcImpl : public OnlineRecognizerImpl {
  public:
   explicit OnlineRecognizerCtcImpl(const OnlineRecognizerConfig &config)
-      : config_(config),
+      : OnlineRecognizerImpl(config),
+        config_(config),
         model_(OnlineCtcModel::Create(config.model_config)),
         sym_(config.model_config.tokens),
         endpoint_(config_.endpoint_config) {
@@ -84,7 +85,8 @@ class OnlineRecognizerCtcImpl : public OnlineRecognizerImpl {
 #if __ANDROID_API__ >= 9
   explicit OnlineRecognizerCtcImpl(AAssetManager *mgr,
                                    const OnlineRecognizerConfig &config)
-      : config_(config),
+      : OnlineRecognizerImpl(mgr, config),
+        config_(config),
         model_(OnlineCtcModel::Create(mgr, config.model_config)),
         sym_(mgr, config.model_config.tokens),
         endpoint_(config_.endpoint_config) {
@@ -182,8 +184,10 @@ class OnlineRecognizerCtcImpl : public OnlineRecognizerImpl {
     // TODO(fangjun): Remember to change these constants if needed
     int32_t frame_shift_ms = 10;
     int32_t subsampling_factor = 4;
-    return Convert(decoder_result, sym_, frame_shift_ms, subsampling_factor,
-                   s->GetCurrentSegment(), s->GetNumFramesSinceStart());
+    auto r = Convert(decoder_result, sym_, frame_shift_ms, subsampling_factor,
+                     s->GetCurrentSegment(), s->GetNumFramesSinceStart());
+    r.text = ApplyInverseTextNormalization(r.text);
+    return r;
   }
 
   bool IsEndpoint(OnlineStream *s) const override {
diff --git a/sherpa-onnx/csrc/online-recognizer-impl.cc b/sherpa-onnx/csrc/online-recognizer-impl.cc
index 2de905772..89d172f97 100644
--- a/sherpa-onnx/csrc/online-recognizer-impl.cc
+++ b/sherpa-onnx/csrc/online-recognizer-impl.cc
@@ -4,11 +4,22 @@
 
 #include "sherpa-onnx/csrc/online-recognizer-impl.h"
 
+#if __ANDROID_API__ >= 9
+#include <strstream>
+
+#include "android/asset_manager.h"
+#include "android/asset_manager_jni.h"
+#endif
+
+#include "fst/extensions/far/far.h"
+#include "kaldifst/csrc/kaldi-fst-io.h"
+#include "sherpa-onnx/csrc/macros.h"
 #include "sherpa-onnx/csrc/online-recognizer-ctc-impl.h"
 #include "sherpa-onnx/csrc/online-recognizer-paraformer-impl.h"
 #include "sherpa-onnx/csrc/online-recognizer-transducer-impl.h"
 #include "sherpa-onnx/csrc/online-recognizer-transducer-nemo-impl.h"
 #include "sherpa-onnx/csrc/onnx-utils.h"
+#include "sherpa-onnx/csrc/text-utils.h"
 
 namespace sherpa_onnx {
 
@@ -78,4 +89,110 @@ std::unique_ptr<OnlineRecognizerImpl> OnlineRecognizerImpl::Create(
 }
 #endif
 
+OnlineRecognizerImpl::OnlineRecognizerImpl(const OnlineRecognizerConfig &config)
+    : config_(config) {
+  if (!config.rule_fsts.empty()) {
+    std::vector<std::string> files;
+    SplitStringToVector(config.rule_fsts, ",", false, &files);
+    itn_list_.reserve(files.size());
+    for (const auto &f : files) {
+      if (config.model_config.debug) {
+        SHERPA_ONNX_LOGE("rule fst: %s", f.c_str());
+      }
+      itn_list_.push_back(std::make_unique<kaldifst::TextNormalizer>(f));
+    }
+  }
+
+  if (!config.rule_fars.empty()) {
+    if (config.model_config.debug) {
+      SHERPA_ONNX_LOGE("Loading FST archives");
+    }
+    std::vector<std::string> files;
+    SplitStringToVector(config.rule_fars, ",", false, &files);
+
+    itn_list_.reserve(files.size() + itn_list_.size());
+
+    for (const auto &f : files) {
+      if (config.model_config.debug) {
+        SHERPA_ONNX_LOGE("rule far: %s", f.c_str());
+      }
+      std::unique_ptr<fst::FarReader<fst::StdArc>> reader(
+          fst::FarReader<fst::StdArc>::Open(f));
+      for (; !reader->Done(); reader->Next()) {
+        std::unique_ptr<fst::StdConstFst> r(
+            fst::CastOrConvertToConstFst(reader->GetFst()->Copy()));
+
+        itn_list_.push_back(
+            std::make_unique<kaldifst::TextNormalizer>(std::move(r)));
+      }
+    }
+
+    if (config.model_config.debug) {
+      SHERPA_ONNX_LOGE("FST archives loaded!");
+    }
+  }
+}
+
+#if __ANDROID_API__ >= 9
+OnlineRecognizerImpl::OnlineRecognizerImpl(AAssetManager *mgr,
+                                           const OnlineRecognizerConfig &config)
+    : config_(config) {
+  if (!config.rule_fsts.empty()) {
+    std::vector<std::string> files;
+    SplitStringToVector(config.rule_fsts, ",", false, &files);
+    itn_list_.reserve(files.size());
+    for (const auto &f : files) {
+      if (config.model_config.debug) {
+        SHERPA_ONNX_LOGE("rule fst: %s", f.c_str());
+      }
+      auto buf = ReadFile(mgr, f);
+      std::istrstream is(buf.data(), buf.size());
+      itn_list_.push_back(std::make_unique<kaldifst::TextNormalizer>(is));
+    }
+  }
+
+  if (!config.rule_fars.empty()) {
+    std::vector<std::string> files;
+    SplitStringToVector(config.rule_fars, ",", false, &files);
+    itn_list_.reserve(files.size() + itn_list_.size());
+
+    for (const auto &f : files) {
+      if (config.model_config.debug) {
+        SHERPA_ONNX_LOGE("rule far: %s", f.c_str());
+      }
+
+      auto buf = ReadFile(mgr, f);
+
+      std::unique_ptr<std::istream> s(
+          new std::istrstream(buf.data(), buf.size()));
+
+      std::unique_ptr<fst::FarReader<fst::StdArc>> reader(
+          fst::FarReader<fst::StdArc>::Open(std::move(s)));
+
+      for (; !reader->Done(); reader->Next()) {
+        std::unique_ptr<fst::StdConstFst> r(
+            fst::CastOrConvertToConstFst(reader->GetFst()->Copy()));
+
+        itn_list_.push_back(
+            std::make_unique<kaldifst::TextNormalizer>(std::move(r)));
+      }  // for (; !reader->Done(); reader->Next())
+    }    // for (const auto &f : files)
+  }      // if (!config.rule_fars.empty())
+}
+#endif
+
+std::string OnlineRecognizerImpl::ApplyInverseTextNormalization(
+    std::string text) const {
+  if (!itn_list_.empty()) {
+    for (const auto &tn : itn_list_) {
+      text = tn->Normalize(text);
+      if (config_.model_config.debug) {
+        SHERPA_ONNX_LOGE("After inverse text normalization: %s", text.c_str());
+      }
+    }
+  }
+
+  return text;
+}
+
 }  // namespace sherpa_onnx
diff --git a/sherpa-onnx/csrc/online-recognizer-impl.h b/sherpa-onnx/csrc/online-recognizer-impl.h
index 72efedec7..8b569f3af 100644
--- a/sherpa-onnx/csrc/online-recognizer-impl.h
+++ b/sherpa-onnx/csrc/online-recognizer-impl.h
@@ -9,6 +9,12 @@
 #include <string>
 #include <vector>
 
+#if __ANDROID_API__ >= 9
+#include "android/asset_manager.h"
+#include "android/asset_manager_jni.h"
+#endif
+
+#include "kaldifst/csrc/text-normalizer.h"
 #include "sherpa-onnx/csrc/macros.h"
 #include "sherpa-onnx/csrc/online-recognizer.h"
 #include "sherpa-onnx/csrc/online-stream.h"
@@ -17,10 +23,15 @@ namespace sherpa_onnx {
 
 class OnlineRecognizerImpl {
  public:
+  explicit OnlineRecognizerImpl(const OnlineRecognizerConfig &config);
+
   static std::unique_ptr<OnlineRecognizerImpl> Create(
       const OnlineRecognizerConfig &config);
 
 #if __ANDROID_API__ >= 9
+  OnlineRecognizerImpl(AAssetManager *mgr,
+                       const OnlineRecognizerConfig &config);
+
   static std::unique_ptr<OnlineRecognizerImpl> Create(
       AAssetManager *mgr, const OnlineRecognizerConfig &config);
 #endif
@@ -50,6 +61,15 @@ class OnlineRecognizerImpl {
   virtual bool IsEndpoint(OnlineStream *s) const = 0;
 
   virtual void Reset(OnlineStream *s) const = 0;
+
+  std::string ApplyInverseTextNormalization(std::string text) const;
+
+ private:
+  OnlineRecognizerConfig config_;
+  // for inverse text normalization. Used only if
+  // config.rule_fsts is not empty or
+  // config.rule_fars is not empty
+  std::vector<std::unique_ptr<kaldifst::TextNormalizer>> itn_list_;
 };
 
 }  // namespace sherpa_onnx
diff --git a/sherpa-onnx/csrc/online-recognizer-paraformer-impl.h b/sherpa-onnx/csrc/online-recognizer-paraformer-impl.h
index 8303af5e3..26fdb08c3 100644
--- a/sherpa-onnx/csrc/online-recognizer-paraformer-impl.h
+++ b/sherpa-onnx/csrc/online-recognizer-paraformer-impl.h
@@ -96,7 +96,8 @@ static void Scale(const float *x, int32_t n, float scale, float *y) {
 class OnlineRecognizerParaformerImpl : public OnlineRecognizerImpl {
  public:
   explicit OnlineRecognizerParaformerImpl(const OnlineRecognizerConfig &config)
-      : config_(config),
+      : OnlineRecognizerImpl(config),
+        config_(config),
         model_(config.model_config),
         sym_(config.model_config.tokens),
         endpoint_(config_.endpoint_config) {
@@ -116,7 +117,8 @@ class OnlineRecognizerParaformerImpl : public OnlineRecognizerImpl {
 #if __ANDROID_API__ >= 9
   explicit OnlineRecognizerParaformerImpl(AAssetManager *mgr,
                                           const OnlineRecognizerConfig &config)
-      : config_(config),
+      : OnlineRecognizerImpl(mgr, config),
+        config_(config),
         model_(mgr, config.model_config),
         sym_(mgr, config.model_config.tokens),
         endpoint_(config_.endpoint_config) {
@@ -160,7 +162,9 @@ class OnlineRecognizerParaformerImpl : public OnlineRecognizerImpl {
   OnlineRecognizerResult GetResult(OnlineStream *s) const override {
     auto decoder_result = s->GetParaformerResult();
 
-    return Convert(decoder_result, sym_);
+    auto r = Convert(decoder_result, sym_);
+    r.text = ApplyInverseTextNormalization(r.text);
+    return r;
   }
 
   bool IsEndpoint(OnlineStream *s) const override {
diff --git a/sherpa-onnx/csrc/online-recognizer-transducer-impl.h b/sherpa-onnx/csrc/online-recognizer-transducer-impl.h
index a2531b10c..2bea765cb 100644
--- a/sherpa-onnx/csrc/online-recognizer-transducer-impl.h
+++ b/sherpa-onnx/csrc/online-recognizer-transducer-impl.h
@@ -80,7 +80,8 @@ OnlineRecognizerResult Convert(const OnlineTransducerDecoderResult &src,
 class OnlineRecognizerTransducerImpl : public OnlineRecognizerImpl {
  public:
   explicit OnlineRecognizerTransducerImpl(const OnlineRecognizerConfig &config)
-      : config_(config),
+      : OnlineRecognizerImpl(config),
+        config_(config),
         model_(OnlineTransducerModel::Create(config.model_config)),
         sym_(config.model_config.tokens),
         endpoint_(config_.endpoint_config) {
@@ -124,7 +125,8 @@ class OnlineRecognizerTransducerImpl : public OnlineRecognizerImpl {
 #if __ANDROID_API__ >= 9
   explicit OnlineRecognizerTransducerImpl(AAssetManager *mgr,
                                           const OnlineRecognizerConfig &config)
-      : config_(config),
+      : OnlineRecognizerImpl(mgr, config),
+        config_(config),
         model_(OnlineTransducerModel::Create(mgr, config.model_config)),
         sym_(mgr, config.model_config.tokens),
         endpoint_(config_.endpoint_config) {
@@ -332,8 +334,10 @@ class OnlineRecognizerTransducerImpl : public OnlineRecognizerImpl {
     // TODO(fangjun): Remember to change these constants if needed
     int32_t frame_shift_ms = 10;
     int32_t subsampling_factor = 4;
-    return Convert(decoder_result, sym_, frame_shift_ms, subsampling_factor,
-                   s->GetCurrentSegment(), s->GetNumFramesSinceStart());
+    auto r = Convert(decoder_result, sym_, frame_shift_ms, subsampling_factor,
+                     s->GetCurrentSegment(), s->GetNumFramesSinceStart());
+    r.text = ApplyInverseTextNormalization(std::move(r.text));
+    return r;
   }
 
   bool IsEndpoint(OnlineStream *s) const override {
diff --git a/sherpa-onnx/csrc/online-recognizer-transducer-nemo-impl.h b/sherpa-onnx/csrc/online-recognizer-transducer-nemo-impl.h
index 2391efb1f..700054dc2 100644
--- a/sherpa-onnx/csrc/online-recognizer-transducer-nemo-impl.h
+++ b/sherpa-onnx/csrc/online-recognizer-transducer-nemo-impl.h
@@ -42,7 +42,8 @@ class OnlineRecognizerTransducerNeMoImpl : public OnlineRecognizerImpl {
  public:
   explicit OnlineRecognizerTransducerNeMoImpl(
       const OnlineRecognizerConfig &config)
-      : config_(config),
+      : OnlineRecognizerImpl(config),
+        config_(config),
         symbol_table_(config.model_config.tokens),
         endpoint_(config_.endpoint_config),
         model_(
@@ -61,7 +62,8 @@ class OnlineRecognizerTransducerNeMoImpl : public OnlineRecognizerImpl {
 #if __ANDROID_API__ >= 9
   explicit OnlineRecognizerTransducerNeMoImpl(
       AAssetManager *mgr, const OnlineRecognizerConfig &config)
-      : config_(config),
+      : OnlineRecognizerImpl(mgr, config),
+        config_(config),
         symbol_table_(mgr, config.model_config.tokens),
         endpoint_(config_.endpoint_config),
         model_(std::make_unique<OnlineTransducerNeMoModel>(
@@ -94,9 +96,11 @@ class OnlineRecognizerTransducerNeMoImpl : public OnlineRecognizerImpl {
     // TODO(fangjun): Remember to change these constants if needed
     int32_t frame_shift_ms = 10;
     int32_t subsampling_factor = model_->SubsamplingFactor();
-    return Convert(s->GetResult(), symbol_table_, frame_shift_ms,
-                   subsampling_factor, s->GetCurrentSegment(),
-                   s->GetNumFramesSinceStart());
+    auto r = Convert(s->GetResult(), symbol_table_, frame_shift_ms,
+                     subsampling_factor, s->GetCurrentSegment(),
+                     s->GetNumFramesSinceStart());
+    r.text = ApplyInverseTextNormalization(std::move(r.text));
+    return r;
   }
 
   bool IsEndpoint(OnlineStream *s) const override {
diff --git a/sherpa-onnx/csrc/online-recognizer.cc b/sherpa-onnx/csrc/online-recognizer.cc
index fcb9169ef..a49a62f6a 100644
--- a/sherpa-onnx/csrc/online-recognizer.cc
+++ b/sherpa-onnx/csrc/online-recognizer.cc
@@ -14,7 +14,9 @@
 #include <utility>
 #include <vector>
 
+#include "sherpa-onnx/csrc/file-utils.h"
 #include "sherpa-onnx/csrc/online-recognizer-impl.h"
+#include "sherpa-onnx/csrc/text-utils.h"
 
 namespace sherpa_onnx {
 
@@ -100,6 +102,15 @@ void OnlineRecognizerConfig::Register(ParseOptions *po) {
                "now support greedy_search and modified_beam_search.");
   po->Register("temperature-scale", &temperature_scale,
                "Temperature scale for confidence computation in decoding.");
+  po->Register(
+      "rule-fsts", &rule_fsts,
+      "If not empty, it specifies fsts for inverse text normalization. "
+      "If there are multiple fsts, they are separated by a comma.");
+
+  po->Register(
+      "rule-fars", &rule_fars,
+      "If not empty, it specifies fst archives for inverse text normalization. "
+      "If there are multiple archives, they are separated by a comma.");
 }
 
 bool OnlineRecognizerConfig::Validate() const {
@@ -129,6 +140,34 @@ bool OnlineRecognizerConfig::Validate() const {
     return false;
   }
 
+  if (!hotwords_file.empty() && !FileExists(hotwords_file)) {
+    SHERPA_ONNX_LOGE("--hotwords-file: '%s' does not exist",
+                     hotwords_file.c_str());
+    return false;
+  }
+
+  if (!rule_fsts.empty()) {
+    std::vector<std::string> files;
+    SplitStringToVector(rule_fsts, ",", false, &files);
+    for (const auto &f : files) {
+      if (!FileExists(f)) {
+        SHERPA_ONNX_LOGE("Rule fst '%s' does not exist. ", f.c_str());
+        return false;
+      }
+    }
+  }
+
+  if (!rule_fars.empty()) {
+    std::vector<std::string> files;
+    SplitStringToVector(rule_fars, ",", false, &files);
+    for (const auto &f : files) {
+      if (!FileExists(f)) {
+        SHERPA_ONNX_LOGE("Rule far '%s' does not exist. ", f.c_str());
+        return false;
+      }
+    }
+  }
+
   return model_config.Validate();
 }
 
@@ -147,7 +186,9 @@ std::string OnlineRecognizerConfig::ToString() const {
   os << "hotwords_file=\"" << hotwords_file << "\", ";
   os << "decoding_method=\"" << decoding_method << "\", ";
   os << "blank_penalty=" << blank_penalty << ", ";
-  os << "temperature_scale=" << temperature_scale << ")";
+  os << "temperature_scale=" << temperature_scale << ", ";
+  os << "rule_fsts=\"" << rule_fsts << "\", ";
+  os << "rule_fars=\"" << rule_fars << "\")";
 
   return os.str();
 }
diff --git a/sherpa-onnx/csrc/online-recognizer.h b/sherpa-onnx/csrc/online-recognizer.h
index f7fcf2f21..7fde367fb 100644
--- a/sherpa-onnx/csrc/online-recognizer.h
+++ b/sherpa-onnx/csrc/online-recognizer.h
@@ -100,6 +100,12 @@ struct OnlineRecognizerConfig {
 
   float temperature_scale = 2.0;
 
+  // If there are multiple rules, they are applied from left to right.
+  std::string rule_fsts;
+
+  // If there are multiple FST archives, they are applied from left to right.
+  std::string rule_fars;
+
   OnlineRecognizerConfig() = default;
 
   OnlineRecognizerConfig(
@@ -109,7 +115,8 @@ struct OnlineRecognizerConfig {
       const OnlineCtcFstDecoderConfig &ctc_fst_decoder_config,
       bool enable_endpoint, const std::string &decoding_method,
       int32_t max_active_paths, const std::string &hotwords_file,
-      float hotwords_score, float blank_penalty, float temperature_scale)
+      float hotwords_score, float blank_penalty, float temperature_scale,
+      const std::string &rule_fsts, const std::string &rule_fars)
       : feat_config(feat_config),
         model_config(model_config),
         lm_config(lm_config),
@@ -121,7 +128,9 @@ struct OnlineRecognizerConfig {
         hotwords_file(hotwords_file),
         hotwords_score(hotwords_score),
         blank_penalty(blank_penalty),
-        temperature_scale(temperature_scale) {}
+        temperature_scale(temperature_scale),
+        rule_fsts(rule_fsts),
+        rule_fars(rule_fars) {}
 
   void Register(ParseOptions *po);
   bool Validate() const;
diff --git a/sherpa-onnx/python/csrc/online-recognizer.cc b/sherpa-onnx/python/csrc/online-recognizer.cc
index 148f73ee5..fe6cd454a 100644
--- a/sherpa-onnx/python/csrc/online-recognizer.cc
+++ b/sherpa-onnx/python/csrc/online-recognizer.cc
@@ -54,19 +54,20 @@ static void PybindOnlineRecognizerResult(py::module *m) {
 static void PybindOnlineRecognizerConfig(py::module *m) {
   using PyClass = OnlineRecognizerConfig;
   py::class_<PyClass>(*m, "OnlineRecognizerConfig")
-      .def(
-          py::init<const FeatureExtractorConfig &, const OnlineModelConfig &,
-                   const OnlineLMConfig &, const EndpointConfig &,
-                   const OnlineCtcFstDecoderConfig &, bool, const std::string &,
-                   int32_t, const std::string &, float, float, float>(),
-          py::arg("feat_config"), py::arg("model_config"),
-          py::arg("lm_config") = OnlineLMConfig(),
-          py::arg("endpoint_config") = EndpointConfig(),
-          py::arg("ctc_fst_decoder_config") = OnlineCtcFstDecoderConfig(),
-          py::arg("enable_endpoint"), py::arg("decoding_method"),
-          py::arg("max_active_paths") = 4, py::arg("hotwords_file") = "",
-          py::arg("hotwords_score") = 0, py::arg("blank_penalty") = 0.0,
-          py::arg("temperature_scale") = 2.0)
+      .def(py::init<const FeatureExtractorConfig &, const OnlineModelConfig &,
+                    const OnlineLMConfig &, const EndpointConfig &,
+                    const OnlineCtcFstDecoderConfig &, bool,
+                    const std::string &, int32_t, const std::string &, float,
+                    float, float, const std::string &, const std::string &>(),
+           py::arg("feat_config"), py::arg("model_config"),
+           py::arg("lm_config") = OnlineLMConfig(),
+           py::arg("endpoint_config") = EndpointConfig(),
+           py::arg("ctc_fst_decoder_config") = OnlineCtcFstDecoderConfig(),
+           py::arg("enable_endpoint"), py::arg("decoding_method"),
+           py::arg("max_active_paths") = 4, py::arg("hotwords_file") = "",
+           py::arg("hotwords_score") = 0, py::arg("blank_penalty") = 0.0,
+           py::arg("temperature_scale") = 2.0, py::arg("rule_fsts") = "",
+           py::arg("rule_fars") = "")
       .def_readwrite("feat_config", &PyClass::feat_config)
       .def_readwrite("model_config", &PyClass::model_config)
       .def_readwrite("lm_config", &PyClass::lm_config)
@@ -79,6 +80,8 @@ static void PybindOnlineRecognizerConfig(py::module *m) {
       .def_readwrite("hotwords_score", &PyClass::hotwords_score)
       .def_readwrite("blank_penalty", &PyClass::blank_penalty)
       .def_readwrite("temperature_scale", &PyClass::temperature_scale)
+      .def_readwrite("rule_fsts", &PyClass::rule_fsts)
+      .def_readwrite("rule_fars", &PyClass::rule_fars)
       .def("__str__", &PyClass::ToString);
 }
 
diff --git a/sherpa-onnx/python/sherpa_onnx/online_recognizer.py b/sherpa-onnx/python/sherpa_onnx/online_recognizer.py
index 97f7472b4..82b2e3b42 100644
--- a/sherpa-onnx/python/sherpa_onnx/online_recognizer.py
+++ b/sherpa-onnx/python/sherpa_onnx/online_recognizer.py
@@ -64,6 +64,8 @@ def from_transducer(
         lm_scale: float = 0.1,
         temperature_scale: float = 2.0,
         debug: bool = False,
+        rule_fsts: str = "",
+        rule_fars: str = "",
     ):
         """
         Please refer to
@@ -148,6 +150,12 @@ def from_transducer(
             the log probability, you can get it from the directory where
             your bpe model is generated. Only used when hotwords provided
             and the modeling unit is bpe or cjkchar+bpe.
+          rule_fsts:
+            If not empty, it specifies fsts for inverse text normalization.
+            If there are multiple fsts, they are separated by a comma.
+          rule_fars:
+            If not empty, it specifies fst archives for inverse text normalization.
+            If there are multiple archives, they are separated by a comma.
         """
         self = cls.__new__(cls)
         _assert_file_exists(tokens)
@@ -217,6 +225,8 @@ def from_transducer(
             hotwords_file=hotwords_file,
             blank_penalty=blank_penalty,
             temperature_scale=temperature_scale,
+            rule_fsts=rule_fsts,
+            rule_fars=rule_fars,
         )
 
         self.recognizer = _Recognizer(recognizer_config)
@@ -239,6 +249,8 @@ def from_paraformer(
         decoding_method: str = "greedy_search",
         provider: str = "cpu",
         debug: bool = False,
+        rule_fsts: str = "",
+        rule_fars: str = "",
     ):
         """
         Please refer to
@@ -283,6 +295,12 @@ def from_paraformer(
             The only valid value is greedy_search.
           provider:
             onnxruntime execution providers. Valid values are: cpu, cuda, coreml.
+          rule_fsts:
+            If not empty, it specifies fsts for inverse text normalization.
+            If there are multiple fsts, they are separated by a comma.
+          rule_fars:
+            If not empty, it specifies fst archives for inverse text normalization.
+            If there are multiple archives, they are separated by a comma.
         """
         self = cls.__new__(cls)
         _assert_file_exists(tokens)
@@ -322,6 +340,8 @@ def from_paraformer(
             endpoint_config=endpoint_config,
             enable_endpoint=enable_endpoint_detection,
             decoding_method=decoding_method,
+            rule_fsts=rule_fsts,
+            rule_fars=rule_fars,
         )
 
         self.recognizer = _Recognizer(recognizer_config)
@@ -345,6 +365,8 @@ def from_zipformer2_ctc(
         ctc_max_active: int = 3000,
         provider: str = "cpu",
         debug: bool = False,
+        rule_fsts: str = "",
+        rule_fars: str = "",
     ):
         """
         Please refer to
@@ -393,6 +415,12 @@ def from_zipformer2_ctc(
             active paths at a time.
           provider:
             onnxruntime execution providers. Valid values are: cpu, cuda, coreml.
+          rule_fsts:
+            If not empty, it specifies fsts for inverse text normalization.
+            If there are multiple fsts, they are separated by a comma.
+          rule_fars:
+            If not empty, it specifies fst archives for inverse text normalization.
+            If there are multiple archives, they are separated by a comma.
         """
         self = cls.__new__(cls)
         _assert_file_exists(tokens)
@@ -433,6 +461,8 @@ def from_zipformer2_ctc(
             ctc_fst_decoder_config=ctc_fst_decoder_config,
             enable_endpoint=enable_endpoint_detection,
             decoding_method=decoding_method,
+            rule_fsts=rule_fsts,
+            rule_fars=rule_fars,
         )
 
         self.recognizer = _Recognizer(recognizer_config)
@@ -454,6 +484,8 @@ def from_nemo_ctc(
         decoding_method: str = "greedy_search",
         provider: str = "cpu",
         debug: bool = False,
+        rule_fsts: str = "",
+        rule_fars: str = "",
     ):
         """
         Please refer to
@@ -497,6 +529,12 @@ def from_nemo_ctc(
             onnxruntime execution providers. Valid values are: cpu, cuda, coreml.
           debug:
             True to show meta data in the model.
+          rule_fsts:
+            If not empty, it specifies fsts for inverse text normalization.
+            If there are multiple fsts, they are separated by a comma.
+          rule_fars:
+            If not empty, it specifies fst archives for inverse text normalization.
+            If there are multiple archives, they are separated by a comma.
         """
         self = cls.__new__(cls)
         _assert_file_exists(tokens)
@@ -533,6 +571,8 @@ def from_nemo_ctc(
             endpoint_config=endpoint_config,
             enable_endpoint=enable_endpoint_detection,
             decoding_method=decoding_method,
+            rule_fsts=rule_fsts,
+            rule_fars=rule_fars,
         )
 
         self.recognizer = _Recognizer(recognizer_config)
@@ -556,6 +596,8 @@ def from_wenet_ctc(
         decoding_method: str = "greedy_search",
         provider: str = "cpu",
         debug: bool = False,
+        rule_fsts: str = "",
+        rule_fars: str = "",
     ):
         """
         Please refer to
@@ -602,6 +644,12 @@ def from_wenet_ctc(
             The only valid value is greedy_search.
           provider:
             onnxruntime execution providers. Valid values are: cpu, cuda, coreml.
+          rule_fsts:
+            If not empty, it specifies fsts for inverse text normalization.
+            If there are multiple fsts, they are separated by a comma.
+          rule_fars:
+            If not empty, it specifies fst archives for inverse text normalization.
+            If there are multiple archives, they are separated by a comma.
         """
         self = cls.__new__(cls)
         _assert_file_exists(tokens)
@@ -640,6 +688,8 @@ def from_wenet_ctc(
             endpoint_config=endpoint_config,
             enable_endpoint=enable_endpoint_detection,
             decoding_method=decoding_method,
+            rule_fsts=rule_fsts,
+            rule_fars=rule_fars,
         )
 
         self.recognizer = _Recognizer(recognizer_config)