diff --git a/audio/aidl/default/EffectFactory.cpp b/audio/aidl/default/EffectFactory.cpp
index 4877956..8e107a2 100644
--- a/audio/aidl/default/EffectFactory.cpp
+++ b/audio/aidl/default/EffectFactory.cpp
@@ -73,6 +73,17 @@
     return ndk::ScopedAStatus::ok();
 }
 
+ndk::ScopedAStatus Factory::queryProcessing(const std::optional<Processing::Type>& in_type,
+                                            std::vector<Processing>* _aidl_return) {
+    // TODO: implement this with audio_effect.xml.
+    if (in_type.has_value()) {
+        // return all matching process filter
+        LOG(DEBUG) << __func__ << " process type: " << in_type.value().toString();
+    }
+    LOG(DEBUG) << __func__ << " return " << _aidl_return->size();
+    return ndk::ScopedAStatus::ok();
+}
+
 #define RETURN_IF_BINDER_EXCEPTION(functor)                                 \
     {                                                                       \
         binder_exception_t exception = functor;                             \
diff --git a/audio/aidl/default/include/effectFactory-impl/EffectFactory.h b/audio/aidl/default/include/effectFactory-impl/EffectFactory.h
index d373048..6195d8a 100644
--- a/audio/aidl/default/include/effectFactory-impl/EffectFactory.h
+++ b/audio/aidl/default/include/effectFactory-impl/EffectFactory.h
@@ -43,6 +43,16 @@
             std::vector<Descriptor::Identity>* out_descriptor) override;
 
     /**
+     * @brief Query list of defined processing, with the optional filter by AudioStreamType
+     *
+     * @param in_type Type of processing, could be AudioStreamType or AudioSource. Optional.
+     * @param _aidl_return List of processing filtered by in_type.
+     * @return ndk::ScopedAStatus
+     */
+    ndk::ScopedAStatus queryProcessing(const std::optional<Processing::Type>& in_type,
+                                       std::vector<Processing>* _aidl_return) override;
+
+    /**
      * @brief Create an effect instance for a certain implementation (identified by UUID).
      *
      * @param in_impl_uuid Effect implementation UUID.