diff --git a/sherpa-onnx/c-api/c-api.cc b/sherpa-onnx/c-api/c-api.cc
index eb9ec8752..cda5832e2 100644
--- a/sherpa-onnx/c-api/c-api.cc
+++ b/sherpa-onnx/c-api/c-api.cc
@@ -308,8 +308,27 @@ struct SherpaOnnxOfflineStream {
       : impl(std::move(p)) {}
 };
 
+static sherpa_onnx::OfflineRecognizerConfig convertConfig(
+    const SherpaOnnxOfflineRecognizerConfig *config);
 SherpaOnnxOfflineRecognizer *CreateOfflineRecognizer(
     const SherpaOnnxOfflineRecognizerConfig *config) {
+  sherpa_onnx::OfflineRecognizerConfig recognizer_config =
+      convertConfig(config);
+
+  if (!recognizer_config.Validate()) {
+    SHERPA_ONNX_LOGE("Errors in config");
+    return nullptr;
+  }
+
+  SherpaOnnxOfflineRecognizer *recognizer = new SherpaOnnxOfflineRecognizer;
+
+  recognizer->impl =
+      std::make_unique<sherpa_onnx::OfflineRecognizer>(recognizer_config);
+
+  return recognizer;
+}
+sherpa_onnx::OfflineRecognizerConfig convertConfig(
+    const SherpaOnnxOfflineRecognizerConfig *config) {
   sherpa_onnx::OfflineRecognizerConfig recognizer_config;
 
   recognizer_config.feat_config.sampling_rate =
@@ -398,17 +417,15 @@ SherpaOnnxOfflineRecognizer *CreateOfflineRecognizer(
     SHERPA_ONNX_LOGE("%s", recognizer_config.ToString().c_str());
   }
 
-  if (!recognizer_config.Validate()) {
-    SHERPA_ONNX_LOGE("Errors in config");
-    return nullptr;
-  }
-
-  SherpaOnnxOfflineRecognizer *recognizer = new SherpaOnnxOfflineRecognizer;
-
-  recognizer->impl =
-      std::make_unique<sherpa_onnx::OfflineRecognizer>(recognizer_config);
+  return recognizer_config;
+}
 
-  return recognizer;
+void SherpaOnnxOfflineRecognizerSetConfig(
+    const SherpaOnnxOfflineRecognizer *recognizer,
+    const SherpaOnnxOfflineRecognizerConfig *config){
+  sherpa_onnx::OfflineRecognizerConfig recognizer_config =
+      convertConfig(config);
+    recognizer->impl->SetConfig(recognizer_config);
 }
 
 void DestroyOfflineRecognizer(SherpaOnnxOfflineRecognizer *recognizer) {
@@ -461,6 +478,13 @@ const SherpaOnnxOfflineRecognizerResult *GetOfflineStreamResult(
   pText[text.size()] = 0;
   r->text = pText;
 
+  //lang
+  const auto &lang = result.lang;
+  char *c_lang = new char[lang.size() + 1];
+  std::copy(lang.begin(), lang.end(), c_lang);
+  c_lang[lang.size()] = '\0';
+  r->lang = c_lang;
+
   // copy json
   std::string json = result.AsJsonString();
   char *pJson = new char[json.size() + 1];
@@ -517,6 +541,7 @@ void DestroyOfflineRecognizerResult(
     delete[] r->tokens;
     delete[] r->tokens_arr;
     delete[] r->json;
+    delete[] r->lang;
     delete r;
   }
 }
diff --git a/sherpa-onnx/c-api/c-api.h b/sherpa-onnx/c-api/c-api.h
index 4beba2a73..e6d8ae272 100644
--- a/sherpa-onnx/c-api/c-api.h
+++ b/sherpa-onnx/c-api/c-api.h
@@ -428,6 +428,11 @@ SHERPA_ONNX_API typedef struct SherpaOnnxOfflineStream SherpaOnnxOfflineStream;
 SHERPA_ONNX_API SherpaOnnxOfflineRecognizer *CreateOfflineRecognizer(
     const SherpaOnnxOfflineRecognizerConfig *config);
 
+/// @param config  Config for the recognizer.
+SHERPA_ONNX_API void SherpaOnnxOfflineRecognizerSetConfig(
+    const SherpaOnnxOfflineRecognizer *recognizer,
+    const SherpaOnnxOfflineRecognizerConfig *config);
+
 /// Free a pointer returned by CreateOfflineRecognizer()
 ///
 /// @param p A pointer returned by CreateOfflineRecognizer()
@@ -491,7 +496,7 @@ SHERPA_ONNX_API void DecodeMultipleOfflineStreams(
 SHERPA_ONNX_API typedef struct SherpaOnnxOfflineRecognizerResult {
   const char *text;
 
-  // Pointer to continuous memory which holds timestamps
+    // Pointer to continuous memory which holds timestamps
   //
   // It is NULL if the model does not support timestamps
   float *timestamps;
@@ -519,6 +524,10 @@ SHERPA_ONNX_API typedef struct SherpaOnnxOfflineRecognizerResult {
    *   }
    */
   const char *json;
+
+  //return recognized language
+  const char *lang;
+
 } SherpaOnnxOfflineRecognizerResult;
 
 /// Get the result of the offline stream.
diff --git a/sherpa-onnx/csrc/offline-recognizer-ctc-impl.h b/sherpa-onnx/csrc/offline-recognizer-ctc-impl.h
index cbe9a9e88..9c7252a06 100644
--- a/sherpa-onnx/csrc/offline-recognizer-ctc-impl.h
+++ b/sherpa-onnx/csrc/offline-recognizer-ctc-impl.h
@@ -212,6 +212,11 @@ class OfflineRecognizerCtcImpl : public OfflineRecognizerImpl {
     }
   }
 
+  OfflineRecognizerConfig GetConfig() const override {
+    return config_;
+  }
+
+
  private:
   // Decode a single stream.
   // Some models do not support batch size > 1, e.g., WeNet CTC models.
diff --git a/sherpa-onnx/csrc/offline-recognizer-impl.cc b/sherpa-onnx/csrc/offline-recognizer-impl.cc
index 80a6766ce..dd96f2b8a 100644
--- a/sherpa-onnx/csrc/offline-recognizer-impl.cc
+++ b/sherpa-onnx/csrc/offline-recognizer-impl.cc
@@ -431,4 +431,8 @@ std::string OfflineRecognizerImpl::ApplyInverseTextNormalization(
   return text;
 }
 
+void OfflineRecognizerImpl::SetConfig(const OfflineRecognizerConfig &config) {
+  config_ = config;
+}
+
 }  // namespace sherpa_onnx
diff --git a/sherpa-onnx/csrc/offline-recognizer-impl.h b/sherpa-onnx/csrc/offline-recognizer-impl.h
index 1ba268c11..32010bf70 100644
--- a/sherpa-onnx/csrc/offline-recognizer-impl.h
+++ b/sherpa-onnx/csrc/offline-recognizer-impl.h
@@ -48,6 +48,10 @@ class OfflineRecognizerImpl {
 
   virtual void DecodeStreams(OfflineStream **ss, int32_t n) const = 0;
 
+  virtual void SetConfig(const OfflineRecognizerConfig &config);
+
+  virtual OfflineRecognizerConfig GetConfig() const = 0;
+
   std::string ApplyInverseTextNormalization(std::string text) const;
 
  private:
diff --git a/sherpa-onnx/csrc/offline-recognizer-paraformer-impl.h b/sherpa-onnx/csrc/offline-recognizer-paraformer-impl.h
index a0d4af3b6..13240cc01 100644
--- a/sherpa-onnx/csrc/offline-recognizer-paraformer-impl.h
+++ b/sherpa-onnx/csrc/offline-recognizer-paraformer-impl.h
@@ -211,6 +211,10 @@ class OfflineRecognizerParaformerImpl : public OfflineRecognizerImpl {
     }
   }
 
+  OfflineRecognizerConfig GetConfig() const override {
+    return config_;
+  }
+
  private:
   std::vector<float> ApplyLFR(const std::vector<float> &in) const {
     int32_t lfr_window_size = model_->LfrWindowSize();
diff --git a/sherpa-onnx/csrc/offline-recognizer-transducer-impl.h b/sherpa-onnx/csrc/offline-recognizer-transducer-impl.h
index c439319eb..05759ac5b 100644
--- a/sherpa-onnx/csrc/offline-recognizer-transducer-impl.h
+++ b/sherpa-onnx/csrc/offline-recognizer-transducer-impl.h
@@ -246,6 +246,11 @@ class OfflineRecognizerTransducerImpl : public OfflineRecognizerImpl {
     }
   }
 
+  OfflineRecognizerConfig GetConfig() const override {
+    return config_;
+  }
+
+
   void InitHotwords() {
     // each line in hotwords_file contains space-separated words
 
diff --git a/sherpa-onnx/csrc/offline-recognizer-transducer-nemo-impl.h b/sherpa-onnx/csrc/offline-recognizer-transducer-nemo-impl.h
index d5902b05b..2f5b9e2a2 100644
--- a/sherpa-onnx/csrc/offline-recognizer-transducer-nemo-impl.h
+++ b/sherpa-onnx/csrc/offline-recognizer-transducer-nemo-impl.h
@@ -139,6 +139,10 @@ class OfflineRecognizerTransducerNeMoImpl : public OfflineRecognizerImpl {
     }
   }
 
+  OfflineRecognizerConfig GetConfig() const override {
+    return config_;
+  }
+
  private:
   void PostInit() {
     config_.feat_config.nemo_normalize_type =
diff --git a/sherpa-onnx/csrc/offline-recognizer-whisper-impl.h b/sherpa-onnx/csrc/offline-recognizer-whisper-impl.h
index e56f07550..023700e77 100644
--- a/sherpa-onnx/csrc/offline-recognizer-whisper-impl.h
+++ b/sherpa-onnx/csrc/offline-recognizer-whisper-impl.h
@@ -45,6 +45,7 @@ static OfflineRecognitionResult Convert(const OfflineWhisperDecoderResult &src,
   }
 
   r.text = text;
+  r.lang = src.lang;
 
   return r;
 }
@@ -100,8 +101,18 @@ class OfflineRecognizerWhisperImpl : public OfflineRecognizerImpl {
     }
   }
 
+  void SetConfig(const OfflineRecognizerConfig &config) override {
+    config_.model_config.whisper = config.model_config.whisper;
+  }
+
+  OfflineRecognizerConfig GetConfig() const override {
+    return config_;
+  }
+
  private:
   void DecodeStream(OfflineStream *s) const {
+    decoder_->SetConfig(config_.model_config.whisper);
+
     int32_t max_num_frames = 3000;
     auto memory_info =
         Ort::MemoryInfo::CreateCpu(OrtDeviceAllocator, OrtMemTypeDefault);
diff --git a/sherpa-onnx/csrc/offline-recognizer.cc b/sherpa-onnx/csrc/offline-recognizer.cc
index 1285a5cd3..f73e35ad6 100644
--- a/sherpa-onnx/csrc/offline-recognizer.cc
+++ b/sherpa-onnx/csrc/offline-recognizer.cc
@@ -156,4 +156,12 @@ void OfflineRecognizer::DecodeStreams(OfflineStream **ss, int32_t n) const {
   impl_->DecodeStreams(ss, n);
 }
 
+void OfflineRecognizer::SetConfig(const OfflineRecognizerConfig &config) {
+    impl_->SetConfig(config);
+}
+
+OfflineRecognizerConfig OfflineRecognizer::GetConfig() const {
+  return impl_->GetConfig();
+}
+
 }  // namespace sherpa_onnx
diff --git a/sherpa-onnx/csrc/offline-recognizer.h b/sherpa-onnx/csrc/offline-recognizer.h
index 9290a53b5..8f0b47a08 100644
--- a/sherpa-onnx/csrc/offline-recognizer.h
+++ b/sherpa-onnx/csrc/offline-recognizer.h
@@ -119,6 +119,15 @@ class OfflineRecognizer {
    */
   void DecodeStreams(OfflineStream **ss, int32_t n) const;
 
+  /** Onnxruntime Session objects are not affected by this method.
+  * The exact behavior can be defined by a specific recognizer impl.
+  * For instance, for the whisper recognizer, you can retrieve the language and task from
+  * the config and ignore any remaining fields in `config`.
+  */
+  void SetConfig(const OfflineRecognizerConfig &config);
+
+  OfflineRecognizerConfig GetConfig() const;
+
  private:
   std::unique_ptr<OfflineRecognizerImpl> impl_;
 };
diff --git a/sherpa-onnx/csrc/offline-stream.h b/sherpa-onnx/csrc/offline-stream.h
index e3c346fc4..0bc7b4a9b 100644
--- a/sherpa-onnx/csrc/offline-stream.h
+++ b/sherpa-onnx/csrc/offline-stream.h
@@ -26,7 +26,9 @@ struct OfflineRecognitionResult {
   // For instance, for BPE-based models it consists of a list of BPE tokens.
   std::vector<std::string> tokens;
 
-  /// timestamps.size() == tokens.size()
+  std::string lang;
+
+    /// timestamps.size() == tokens.size()
   /// timestamps[i] records the time in seconds when tokens[i] is decoded.
   std::vector<float> timestamps;
 
diff --git a/sherpa-onnx/csrc/offline-whisper-decoder.h b/sherpa-onnx/csrc/offline-whisper-decoder.h
index c9367eafd..3babb3824 100644
--- a/sherpa-onnx/csrc/offline-whisper-decoder.h
+++ b/sherpa-onnx/csrc/offline-whisper-decoder.h
@@ -6,14 +6,17 @@
 #define SHERPA_ONNX_CSRC_OFFLINE_WHISPER_DECODER_H_
 
 #include <vector>
+#include <string>
 
 #include "onnxruntime_cxx_api.h"  // NOLINT
+#include "sherpa-onnx/csrc/offline-whisper-model-config.h"
 
 namespace sherpa_onnx {
 
 struct OfflineWhisperDecoderResult {
   /// The decoded token IDs
   std::vector<int32_t> tokens;
+  std::string lang;
 };
 
 class OfflineWhisperDecoder {
@@ -31,6 +34,9 @@ class OfflineWhisperDecoder {
    */
   virtual std::vector<OfflineWhisperDecoderResult> Decode(
       Ort::Value n_layer_cross_k, Ort::Value n_layer_cross_v) = 0;
+
+  virtual void SetConfig(const OfflineWhisperModelConfig &config) = 0;
+
 };
 
 }  // namespace sherpa_onnx
diff --git a/sherpa-onnx/csrc/offline-whisper-greedy-search-decoder.cc b/sherpa-onnx/csrc/offline-whisper-greedy-search-decoder.cc
index 15eacb62b..96bb9d971 100644
--- a/sherpa-onnx/csrc/offline-whisper-greedy-search-decoder.cc
+++ b/sherpa-onnx/csrc/offline-whisper-greedy-search-decoder.cc
@@ -12,6 +12,10 @@
 
 namespace sherpa_onnx {
 
+void OfflineWhisperGreedySearchDecoder::SetConfig(const OfflineWhisperModelConfig &config) {
+  config_ = config;
+}
+
 std::vector<OfflineWhisperDecoderResult>
 OfflineWhisperGreedySearchDecoder::Decode(Ort::Value cross_k,
                                           Ort::Value cross_v) {
@@ -129,6 +133,13 @@ OfflineWhisperGreedySearchDecoder::Decode(Ort::Value cross_k,
 
   std::vector<OfflineWhisperDecoderResult> ans(1);
 
+  const auto &id2lang = model_->GetID2Lang();
+  if (id2lang.count(initial_tokens[1])) {
+      ans[0].lang = id2lang.at(initial_tokens[1]);
+  } else {
+      ans[0].lang = "";
+  }
+
   ans[0].tokens = std::move(predicted_tokens);
 
   return ans;
diff --git a/sherpa-onnx/csrc/offline-whisper-greedy-search-decoder.h b/sherpa-onnx/csrc/offline-whisper-greedy-search-decoder.h
index 5f2b41680..9692d90d8 100644
--- a/sherpa-onnx/csrc/offline-whisper-greedy-search-decoder.h
+++ b/sherpa-onnx/csrc/offline-whisper-greedy-search-decoder.h
@@ -8,7 +8,6 @@
 #include <vector>
 
 #include "sherpa-onnx/csrc/offline-whisper-decoder.h"
-#include "sherpa-onnx/csrc/offline-whisper-model-config.h"
 #include "sherpa-onnx/csrc/offline-whisper-model.h"
 
 namespace sherpa_onnx {
@@ -22,6 +21,8 @@ class OfflineWhisperGreedySearchDecoder : public OfflineWhisperDecoder {
   std::vector<OfflineWhisperDecoderResult> Decode(Ort::Value cross_k,
                                                   Ort::Value cross_v) override;
 
+  void SetConfig(const OfflineWhisperModelConfig &config) override;
+
  private:
   OfflineWhisperModelConfig config_;
   OfflineWhisperModel *model_;  // not owned