diff --git a/flex/engines/graph_db/app/builtin/TVSP.cc b/flex/engines/graph_db/app/builtin/TVSP.cc
new file mode 100644
index 000000000000..17efb1af639f
--- /dev/null
+++ b/flex/engines/graph_db/app/builtin/TVSP.cc
@@ -0,0 +1,228 @@
+/** Copyright 2020 Alibaba Group Holding Limited.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "flex/engines/graph_db/app/builtin/TVSP.h"
+
+namespace gs {
+
+bool TVSP::DoQuery(GraphDBSession& sess, Decoder& input,Encoder& output) {
+    ReadTransaction txn = sess.GetReadTransaction(); 
+    if (input.empty()) {
+        return false;
+    }
+    Schema schema_ = txn.schema();
+    std::string label_name1{input.get_string()};
+    vid_t vid1=input.get_int();
+    std::string label_name2{input.get_string()};
+    vid_t vid2=input.get_int();
+    std::string label_name3{input.get_string()};
+    vid_t vid3=input.get_int();
+
+    if(!schema_.has_vertex_label(label_name1)||!schema_.has_vertex_label(label_name2)
+                                                ||!schema_.has_vertex_label(label_name3)){
+        output.put_string_view("The requested label doesn't exits.");
+        return false;  // The requested label doesn't exits.
+    }
+    label_t label_v1=schema_.get_vertex_label_id(label_name1);
+    label_t label_v2=schema_.get_vertex_label_id(label_name2);
+    label_t label_v3=schema_.get_vertex_label_id(label_name3);
+    vid_t index_v1{};
+    vid_t index_v2{};
+    vid_t index_v3{};   
+    if(!txn.GetVertexIndex(label_v1, (int64_t)vid1, index_v1)||
+            !txn.GetVertexIndex(label_v2, (int64_t)vid2, index_v2)||
+            !txn.GetVertexIndex(label_v3, (int64_t)vid3, index_v3))
+    {
+        output.put_string_view("get index fail.");
+        return false;
+    }
+    
+    uint vertex_num = 0 ;
+    for(label_t i = 0 ; i<schema_.vertex_label_num();i++){
+        vertex_num+=txn.GetVertexNum(i);
+    }
+    std::vector<int64_t> v1v2result_;
+    std::vector<int64_t> v2v3result_;
+    std::vector<int64_t> v1v3result_;
+
+    bool find_flag = true;
+    if(!ShortestPath(txn,label_v1,index_v1,label_v2,index_v2,v1v2result_,vertex_num)){
+        find_flag=false;
+    }
+    if(find_flag&&!ShortestPath(txn,label_v2,index_v2,label_v3,index_v3,v2v3result_,vertex_num)){
+        find_flag=false;
+    }
+    if(find_flag&&!ShortestPath(txn,label_v1,index_v1,label_v3,index_v3,v1v3result_,vertex_num)){
+        find_flag=false;
+    }
+    std::string result_path = "";
+    if(find_flag){
+        //选择最短的两条路径进行连接
+        std::vector<int64_t> TSP = ConnectPath(v1v2result_,v2v3result_,v1v3result_);
+        for(auto it = TSP.begin(); it != TSP.end(); ++it){
+            if (std::next(it) != TSP.end()) {
+                result_path += std::to_string(*it)+"--";  // 如果当前元素不是最后一个，则添加空格
+            }
+            else{
+                result_path += std::to_string(*it);
+            }
+        }
+    }
+    else{
+        result_path="no path find!";
+    }
+    
+    // 向CollectiveResults中添加多个Results对象
+    results::CollectiveResults results;
+    auto result = results.add_results();
+    result->mutable_record()
+      ->add_columns()
+      ->mutable_entry()
+      ->mutable_element()
+      ->mutable_object()
+      ->set_str(result_path);
+
+    output.put_string_view(results.SerializeAsString());
+    txn.Commit();
+    return true;
+}
+
+bool TVSP::ShortestPath(const gs::ReadTransaction& txn, label_t v1_l,vid_t v1_index,label_t v2_l,vid_t v2_index,std::vector<int64_t> &result_, uint vertex_num){ 
+    Schema schema_ = txn.schema();
+    int vertex_size_ = (int)schema_.vertex_label_num();
+    int edge_size_ = (int)schema_.edge_label_num();
+
+    std::vector<bool> visited(vertex_num+1, false);
+    std::unordered_map<int64_t, int64_t> parent;
+    std::vector<label_t> nei_label_;
+    std::vector<vid_t> nei_index_;
+    int64_t v1_id = txn.GetVertexId(v1_l, v1_index).AsInt64();
+    int64_t v2_id = txn.GetVertexId(v2_l, v2_index).AsInt64();
+
+    // std::cout<<"v1: "<<v1_id<<std::endl;
+    // std::cout<<"v2: "<<v2_id<<std::endl;
+    parent[v1_id] = -1;
+    nei_label_.push_back(v1_l);
+    nei_index_.push_back(v1_index);
+    visited[v1_id] = true;
+
+    std::vector<label_t> next_nei_labels_;
+    std::vector<vid_t> next_nei_indexs_;
+    bool find = false;
+    while(!nei_label_.empty()&&!find) {
+        for(long unsigned int i = 0 ; i< nei_index_.size();i++){
+            for(int j = 0 ; j<vertex_size_;j++){
+                for(int k = 0 ; k<edge_size_;k++){
+                    std::string vertex_name = schema_.get_vertex_label_name(label_t(nei_label_[i]));
+                    std::string nei_name = schema_.get_vertex_label_name(label_t(j));
+                    std::string edge_name = schema_.get_edge_label_name(label_t(k));
+                    if(schema_.has_edge_label(vertex_name,nei_name,edge_name)){
+                        auto outedges = txn.GetOutEdgeIterator(nei_label_[i],nei_index_[i],j,k);//1.self_label 2.self_index 3.edge_label 4.nei_label
+                        while(outedges.IsValid()){
+                            auto neighbor = outedges.GetNeighbor();
+                            int64_t v_id = txn.GetVertexId(j, neighbor).AsInt64();
+                            std::cout<<v_id<<std::endl;
+                            if(!visited[v_id]) {
+                                next_nei_labels_.push_back(j);
+                                next_nei_indexs_.push_back(neighbor);
+                                visited[v_id] = true;
+                                parent[v_id] = txn.GetVertexId(nei_label_[i], nei_index_[i]).AsInt64();
+                                if(v_id == v2_id) {
+                                    find = true;
+                                    break;
+                                }
+                            }
+                            outedges.Next();
+                        }
+                    }
+                    if(schema_.has_edge_label(nei_name,vertex_name,edge_name)){
+                        auto inedges = txn.GetInEdgeIterator(nei_label_[i],nei_index_[i],j,k);//1.self_label 2.self_index 3.edge_label 4.nei_label
+                        while(inedges.IsValid()){
+                            auto neighbor = inedges.GetNeighbor();
+                            int64_t v_id = txn.GetVertexId(j, neighbor).AsInt64();
+                            if(!visited[v_id]) {
+                                next_nei_labels_.push_back(j);
+                                next_nei_indexs_.push_back(neighbor);
+                                visited[v_id] = true;
+                                parent[v_id] = txn.GetVertexId(nei_label_[i], nei_index_[i]).AsInt64();
+                                if(v_id == v2_id) {
+                                    find = true;
+                                    break;
+                                }
+                            }
+                            inedges.Next();
+                        }
+                    }
+                }
+                if(find) break;
+            }
+            if(find) break;
+        }
+        if(find) break;
+        nei_label_ = next_nei_labels_;
+        nei_index_ = next_nei_indexs_;
+        next_nei_labels_.clear();
+        next_nei_indexs_.clear();
+    }
+    if(find) {
+      int64_t v = v2_id;
+      while(v != -1) {
+        result_.push_back(v);
+        v = parent[v];
+        std::cout<<v<<std::endl;
+      }
+      std::reverse(result_.begin(), result_.end());
+      return true;
+    }
+    else {
+      return false;
+    }
+}
+
+std::vector<int64_t> TVSP::ConnectPath(std::vector<int64_t> &path1,std::vector<int64_t> &path2,
+                                 std::vector<int64_t> &path3){
+    std::vector<int64_t> TSP;
+    int v1v2size = (int)path1.size();
+    int v2v3size = (int)path2.size();
+    int v1v3size = (int)path3.size();
+    if(v1v2size<=v2v3size&&v1v3size<=v2v3size){
+        for(int i =v1v2size-1;i>=0;i--){
+            TSP.push_back(path1[i]);
+        }
+        for(int i = 1;i<v1v3size;i++){
+            TSP.push_back(path3[i]);
+        }
+    }
+    else if(v1v2size<=v1v3size&&v2v3size<=v1v3size){
+        for(int i= 0;i<v1v2size;i++){
+            TSP.push_back(path1[i]);
+        }
+        for(int i = 1;i<v2v3size;i++){
+            TSP.push_back(path2[i]);
+        }
+    }
+    else if(v2v3size<=v1v2size&&v1v3size<=v1v2size){
+        for(int i = 0;i<v2v3size;i++){
+            TSP.push_back(path2[i]);
+        }
+        for(int i = v1v3size-2;i>=0;i--){
+            TSP.push_back(path3[i]);
+        }
+    }
+    return TSP;
+}
+AppWrapper TVSPFactory::CreateApp(const GraphDB& db) {
+  return AppWrapper(new TVSP(), NULL);
+}
+}  // namespace gs
diff --git a/flex/engines/graph_db/app/builtin/TVSP.h b/flex/engines/graph_db/app/builtin/TVSP.h
new file mode 100644
index 000000000000..0c43c2c378d9
--- /dev/null
+++ b/flex/engines/graph_db/app/builtin/TVSP.h
@@ -0,0 +1,50 @@
+/** Copyright 2020 Alibaba Group Holding Limited.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ENGINES_GRAPH_DB_APP_BUILDIN_TVSP_H_
+#define ENGINES_GRAPH_DB_APP_BUILDIN_TVSP_H_
+#include "flex/engines/graph_db/database/graph_db_session.h"
+#include "flex/engines/hqps_db/app/interactive_app_base.h"
+
+namespace gs {
+// A simple app to count the number of vertices of a given label.
+class TVSP : public CypherInternalPbWriteAppBase {
+ private:
+//  std::string label_name1;
+//  int32_t vid1;
+//  std::string label_name2;
+//  int32_t vid2;
+//  std::string label_name3;
+//  int32_t vid3;
+
+ public:
+  TVSP() {}
+  bool DoQuery(GraphDBSession& sess, Decoder& input, Encoder& output) override;
+  bool ShortestPath(const gs::ReadTransaction& txn, label_t v1_l,vid_t v1_index,label_t v2_l,vid_t v2_index,std::vector<int64_t> &result_, uint vertex_num); 
+  std::vector<int64_t> ConnectPath(std::vector<int64_t> &path1,std::vector<int64_t> &path2,std::vector<int64_t> &path3);
+
+};
+
+class TVSPFactory : public AppFactoryBase {
+ public:
+  TVSPFactory() = default;
+  ~TVSPFactory() = default;
+
+  AppWrapper CreateApp(const GraphDB& db) override;
+};
+
+}  // namespace gs
+
+#endif  // ENGINES_GRAPH_DB_APP_BUILDIN_TVSP_H_
\ No newline at end of file
diff --git a/flex/engines/graph_db/app/builtin/k_degree_neighbors.cc b/flex/engines/graph_db/app/builtin/k_degree_neighbors.cc
new file mode 100644
index 000000000000..f5fa5deaeeb5
--- /dev/null
+++ b/flex/engines/graph_db/app/builtin/k_degree_neighbors.cc
@@ -0,0 +1,116 @@
+/** Copyright 2020 Alibaba Group Holding Limited.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "flex/engines/graph_db/app/builtin/k_degree_neighbors.h"
+
+namespace gs {
+
+bool KNeighbors::DoQuery(GraphDBSession& sess, Decoder& input,
+                            Encoder& output) {
+  // 创建一个CollectiveResults对象
+    auto txn = sess.GetReadTransaction(); 
+    Schema schema_ = txn.schema();
+    if (input.empty()) {
+        return false;
+    }
+    this->vertex_id_=input.get_int();
+    std::string label_name { input.get_string()};
+    this->k=input.get_int();
+    
+    if(k<=0) {
+        output.put_string_view("k must be greater than 0.");
+        return false;
+    }
+    if(!schema_.has_vertex_label(label_name)){
+        output.put_string_view("The requested label doesn't exits.");
+        return false;  // The requested label doesn't exits.
+    }
+    this->vertex_label_=schema_.get_vertex_label_id(label_name);
+
+
+    std::set<int64_t> k_neighbors;
+
+    int vertex_size_ = (int)schema_.vertex_label_num();
+    int edge_size_ = (int)schema_.edge_label_num();
+    
+    std::vector<vid_t> nei_index_;
+    std::vector<label_t> nei_label_;
+    std::vector<vid_t> next_nei_indexs_;
+    std::vector<label_t> next_nei_label_;
+
+    nei_label_.push_back(vertex_label_);
+    vid_t vertex_index{};
+    if(!txn.GetVertexIndex(vertex_label_, (int64_t)vertex_id_, vertex_index)){
+        output.put_string_view("get index fail.");
+        return false;
+    }
+    nei_index_.push_back(vertex_index);
+    //层次遍历得到k跳邻居
+    while(!nei_index_.empty() && k > 0) {
+        for(long unsigned int i = 0 ; i<nei_index_.size();i++){
+            for(int j = 0 ; j<vertex_size_;j++){
+                for(int k = 0 ; k<edge_size_;k++){
+                    std::string vertex_name = schema_.get_vertex_label_name(label_t(nei_label_[i]));
+                    std::string nei_name = schema_.get_vertex_label_name(label_t(j));
+                    std::string edge_name = schema_.get_edge_label_name(label_t(k));
+                    if(schema_.has_edge_label(vertex_name,nei_name,edge_name)){
+                        auto outedges = txn.GetOutEdgeIterator(nei_label_[i],nei_index_[i],j,k);//1.self_label 2.self_index 3.edge_label 4.nei_label
+                        while(outedges.IsValid()){
+                            auto neighbor = outedges.GetNeighbor();
+                            next_nei_label_.push_back(j);
+                            next_nei_indexs_.push_back(neighbor);
+                            k_neighbors.insert(txn.GetVertexId(j, neighbor).AsInt64());
+                            outedges.Next();
+                        }
+                    }
+                    if(schema_.has_edge_label(nei_name,vertex_name,edge_name)){
+                        auto inedges = txn.GetInEdgeIterator(nei_label_[i],nei_index_[i],j,k);//1.self_label 2.self_index 3.edge_label 4.nei_label
+                        while(inedges.IsValid()){
+                            auto neighbor = inedges.GetNeighbor();
+                            next_nei_label_.push_back(j);
+                            next_nei_indexs_.push_back(neighbor);
+                            k_neighbors.insert(txn.GetVertexId(j, neighbor).AsInt64());
+                            inedges.Next();
+                        }
+                    }
+              }
+          }
+        }
+        nei_index_ = next_nei_indexs_;
+        nei_label_ = next_nei_label_;
+        next_nei_label_.clear();
+        next_nei_indexs_.clear();
+        k--;
+    }
+    std::string res = "";
+    for(auto it:k_neighbors){
+        res+=(std::to_string(it)+" ");
+    }
+    results::CollectiveResults results;
+    auto result = results.add_results();
+        result->mutable_record()
+        ->add_columns()
+        ->mutable_entry()
+        ->mutable_element()
+        ->mutable_object()
+        ->set_str(res);
+    output.put_string_view(results.SerializeAsString());
+    txn.Commit();
+    return true;
+}
+
+AppWrapper KNeighborsFactory::CreateApp(const GraphDB& db) {
+  return AppWrapper(new KNeighbors(), NULL);
+}
+}  // namespace gs
diff --git a/flex/engines/graph_db/app/builtin/k_degree_neighbors.h b/flex/engines/graph_db/app/builtin/k_degree_neighbors.h
new file mode 100644
index 000000000000..543c4212ddb8
--- /dev/null
+++ b/flex/engines/graph_db/app/builtin/k_degree_neighbors.h
@@ -0,0 +1,43 @@
+/** Copyright 2020 Alibaba Group Holding Limited.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ENGINES_GRAPH_DB_APP_BUILDIN_K_DEGREE_NEI_
+#define ENGINES_GRAPH_DB_APP_BUILDIN_K_DEGREE_NEI_
+#include "flex/engines/graph_db/database/graph_db_session.h"
+#include "flex/engines/hqps_db/app/interactive_app_base.h"
+
+namespace gs {
+// A simple app to count the number of vertices of a given label.
+class KNeighbors : public CypherInternalPbWriteAppBase {
+ private:
+  vid_t vertex_id_;
+  label_t vertex_label_;
+  int32_t k;
+ public:
+  KNeighbors() {}
+  bool DoQuery(GraphDBSession& sess, Decoder& input, Encoder& output) override;
+};
+
+class KNeighborsFactory : public AppFactoryBase {
+ public:
+  KNeighborsFactory() = default;
+  ~KNeighborsFactory() = default;
+
+  AppWrapper CreateApp(const GraphDB& db) override;
+};
+
+}  // namespace gs
+
+#endif  // ENGINES_GRAPH_DB_APP_BUILDIN_COUNT_VERTICES_H_
\ No newline at end of file
diff --git a/flex/engines/graph_db/app/builtin/pagerank.cc b/flex/engines/graph_db/app/builtin/pagerank.cc
new file mode 100644
index 000000000000..d32e6cdbff9a
--- /dev/null
+++ b/flex/engines/graph_db/app/builtin/pagerank.cc
@@ -0,0 +1,134 @@
+/** Copyright 2020 Alibaba Group Holding Limited.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "flex/engines/graph_db/app/builtin/pagerank.h"
+
+namespace gs {
+
+
+bool PageRank::DoQuery(GraphDBSession& sess, Decoder& input,
+                            Encoder& output) {
+  // First get the read transaction.
+  auto txn = sess.GetReadTransaction();
+  // We expect one param of type string from decoder.
+  if (input.empty()) {
+    return false;
+  }
+  std::string vertex_label{input.get_string()};
+  std::string edge_label{input.get_string()};
+
+  if(!input.empty()) {
+    damping_factor_ = input.get_double();
+    max_iterations_ = input.get_int();
+    epsilon_ = input.get_double();
+  }
+
+  vertex_label_id_ = sess.schema().get_vertex_label_id(vertex_label);
+  edge_label_id_ = sess.schema().get_edge_label_id(edge_label);
+
+  // 统计顶点数量
+  auto num_vertices = txn.GetVertexNum(vertex_label_id_);
+
+  // 初始化每个顶点的PageRank值为 1.0 / num_vertices
+  std::unordered_map<vid_t, double> pagerank;
+  std::unordered_map<vid_t, double> new_pagerank;
+
+  auto vertex_iter = txn.GetVertexIterator(vertex_label_id_);
+
+  while (vertex_iter.IsValid()) {
+      vid_t vid = vertex_iter.GetIndex();
+      pagerank[vid] = 1.0 / num_vertices;
+      new_pagerank[vid] = 0.0;
+      vertex_iter.Next();
+  }
+
+  // 获取点的出度
+  std::unordered_map<vid_t, double> outdegree;
+
+  // 开始迭代计算PageRank值
+  for (int iter = 0; iter < max_iterations_; ++iter) {
+      // 初始化新的PageRank值
+      for (auto& kv : new_pagerank) {
+          kv.second = 0.0;
+      }
+
+      // 遍历所有顶点
+      auto vertex_iter = txn.GetVertexIterator(vertex_label_id_);
+      while (vertex_iter.IsValid()) {
+      vid_t v = vertex_iter.GetIndex();
+      
+      // 遍历所有出边并累加其PageRank贡献值
+      double sum = 0.0;
+      auto edges = txn.GetInEdgeIterator(vertex_label_id_, v, vertex_label_id_, edge_label_id_);
+      while(edges.IsValid()){
+          auto neighbor = edges.GetNeighbor();
+          if(outdegree[neighbor] == 0){
+              auto out_edges = txn.GetOutEdgeIterator(vertex_label_id_, neighbor, vertex_label_id_, edge_label_id_);
+              while(out_edges.IsValid()){
+                  outdegree[neighbor]++;
+                  out_edges.Next();
+              }
+          }
+          sum += pagerank[neighbor] / outdegree[neighbor];
+          edges.Next();
+      }
+
+      // 计算新的PageRank值
+      new_pagerank[v] = damping_factor_ * sum + (1.0 - damping_factor_) / num_vertices;
+      vertex_iter.Next();
+      }
+
+      // 检查收敛
+      double diff = 0.0;
+      for (const auto& kv : pagerank) {
+          diff += std::abs(new_pagerank[kv.first] - kv.second);
+      }
+
+      // 如果收敛，则停止迭代
+      if (diff < epsilon_) {
+          break;
+      }
+
+      // 交换pagerank与new_pagerank的内容
+      std::swap(pagerank, new_pagerank);
+  }
+
+  std::ostringstream output_stream;
+  for(auto kv : pagerank) {
+      auto id =txn.GetVertexId(vertex_label_id_, kv.first).AsInt64();
+      // output.put_int(static_cast<int>(id));
+      // output.put_double(kv.second);
+      output_stream << "vertex: " << id << ", pagerank: " << kv.second << "\n";
+  }
+  std::string res_string = output_stream.str();
+  results::CollectiveResults results;
+    auto result = results.add_results();
+  
+    result->mutable_record()
+    ->add_columns()
+    ->mutable_entry()
+    ->mutable_element()
+    ->mutable_object()
+    ->set_str(res_string);
+    
+    output.put_string_view(results.SerializeAsString());
+
+  txn.Commit();
+  return true;
+}
+
+AppWrapper PageRankFactory::CreateApp(const GraphDB& db) {
+  return AppWrapper(new PageRank(), NULL);
+}
+}  // namespace gs
diff --git a/flex/engines/graph_db/app/builtin/pagerank.h b/flex/engines/graph_db/app/builtin/pagerank.h
new file mode 100644
index 000000000000..46d31bce78e6
--- /dev/null
+++ b/flex/engines/graph_db/app/builtin/pagerank.h
@@ -0,0 +1,52 @@
+/** Copyright 2020 Alibaba Group Holding Limited.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ENGINES_GRAPH_DB_APP_BUILDIN_PAGERANK_H_
+#define ENGINES_GRAPH_DB_APP_BUILDIN_PAGERANK_H_
+#include "flex/engines/graph_db/database/graph_db_session.h"
+#include "flex/engines/hqps_db/app/interactive_app_base.h"
+
+namespace gs {
+// A simple app to count the number of vertices of a given label.
+class PageRank : public CypherInternalPbWriteAppBase {
+ public:
+  PageRank() 
+      : damping_factor_(0.85), 
+        max_iterations_(100), 
+        epsilon_(1e-6), 
+        vertex_label_id_(0),
+        edge_label_id_(0) {}
+  bool DoQuery(GraphDBSession& sess, Decoder& input, Encoder& output) override;
+
+ private:
+  double damping_factor_;
+  int max_iterations_;
+  double epsilon_;
+
+  label_t vertex_label_id_;
+  label_t edge_label_id_;
+};
+
+class PageRankFactory : public AppFactoryBase {
+ public:
+  PageRankFactory() = default;
+  ~PageRankFactory() = default;
+
+  AppWrapper CreateApp(const GraphDB& db) override;
+};
+
+}  // namespace gs
+
+#endif  // ENGINES_GRAPH_DB_APP_BUILDIN_PAGERANK_H_
\ No newline at end of file
diff --git a/flex/engines/graph_db/database/graph_db.cc b/flex/engines/graph_db/database/graph_db.cc
index 0aa50c6b0624..286674abba2a 100644
--- a/flex/engines/graph_db/database/graph_db.cc
+++ b/flex/engines/graph_db/database/graph_db.cc
@@ -16,6 +16,9 @@
 #include "flex/engines/graph_db/database/graph_db.h"
 #include "flex/engines/graph_db/app/adhoc_app.h"
 #include "flex/engines/graph_db/app/builtin/count_vertices.h"
+#include "flex/engines/graph_db/app/builtin/pagerank.h"
+#include "flex/engines/graph_db/app/builtin/k_degree_neighbors.h"
+#include "flex/engines/graph_db/app/builtin/TVSP.h"
 #include "flex/engines/graph_db/app/hqps_app.h"
 #include "flex/engines/graph_db/app/server_app.h"
 #include "flex/engines/graph_db/database/graph_db_session.h"
@@ -408,6 +411,13 @@ void GraphDB::initApps(
   app_factories_[0] = std::make_shared<ServerAppFactory>();
   app_factories_[Schema::BUILTIN_COUNT_VERTICES_PLUGIN_ID] =
       std::make_shared<CountVerticesFactory>();
+  app_factories_[Schema::BUILTIN_PAGERANK_PLUGIN_ID] =
+      std::make_shared<PageRankFactory>();
+  app_factories_[Schema::BUILTIN_K_DEGREE_NEIGHBORS_PLUGIN_ID] =
+      std::make_shared<KNeighborsFactory>();
+  app_factories_[Schema::BUILTIN_TVSP_PLUGIN_ID] =
+      std::make_shared<TVSPFactory>();
+
   app_factories_[Schema::HQPS_ADHOC_READ_PLUGIN_ID] =
       std::make_shared<HQPSAdhocReadAppFactory>();
   app_factories_[Schema::HQPS_ADHOC_WRITE_PLUGIN_ID] =
diff --git a/flex/storages/metadata/graph_meta_store.cc b/flex/storages/metadata/graph_meta_store.cc
index 8a9041c272b2..ef7eff176fb3 100644
--- a/flex/storages/metadata/graph_meta_store.cc
+++ b/flex/storages/metadata/graph_meta_store.cc
@@ -56,6 +56,8 @@ const std::vector<PluginMeta>& get_builtin_plugin_metas() {
   static std::vector<PluginMeta> builtin_plugins;
   static bool initialized = false;
   if (!initialized) {
+
+    // count_vertices
     PluginMeta count_vertices;
     count_vertices.id = "count_vertices";
     count_vertices.name = "count_vertices";
@@ -69,6 +71,64 @@ const std::vector<PluginMeta>& get_builtin_plugin_metas() {
     count_vertices.returns.push_back({"count", PropertyType::kInt32});
     initialized = true;
     builtin_plugins.push_back(count_vertices);
+
+    // pagerank
+    PluginMeta pagerank;
+    pagerank.id = "pagerank";
+    pagerank.name = "pagerank";
+    pagerank.description = "A builtin plugin to calculate pagerank";
+    pagerank.enable = true;
+    pagerank.runnable = true;
+    pagerank.type = "cypher";
+    pagerank.creation_time = GetCurrentTimeStamp();
+    pagerank.update_time = GetCurrentTimeStamp();
+    pagerank.params.push_back({"vertex_label", PropertyType::kString});
+    pagerank.params.push_back({"edge_label", PropertyType::kString});
+    pagerank.params.push_back({"damping_factor_", PropertyType::kDouble});
+    pagerank.params.push_back({"max_iterations_", PropertyType::kInt32});
+    pagerank.params.push_back({"epsilon_", PropertyType::kDouble});
+    pagerank.returns.push_back({"pagerank", PropertyType::kString});
+    initialized = true;
+    builtin_plugins.push_back(pagerank);
+
+    // k_neighbors
+    PluginMeta k_neighbors;
+    k_neighbors.id = "k_neighbors";
+    k_neighbors.name = "k_neighbors";
+    k_neighbors.description = "A builtin plugin to calculate k_neighbors";
+    k_neighbors.enable = true;
+    k_neighbors.runnable = true;
+    k_neighbors.type = "cypher";
+    k_neighbors.creation_time = GetCurrentTimeStamp();
+    k_neighbors.update_time = GetCurrentTimeStamp();
+    k_neighbors.params.push_back({"vid", PropertyType::kInt32});
+    k_neighbors.params.push_back({"label_name", PropertyType::kString});
+    k_neighbors.params.push_back({"k", PropertyType::kInt32});
+    k_neighbors.returns.push_back({"k_neighbors", PropertyType::kString});
+    initialized = true;
+    builtin_plugins.push_back(k_neighbors);
+
+    // TVSP
+    PluginMeta TVSP;
+    TVSP.id = "TVSP";
+    TVSP.name = "TVSP";
+    TVSP.description = "A builtin plugin to calculate TVSP";
+    TVSP.enable = true;
+    TVSP.runnable = true;
+    TVSP.type = "cypher";
+    TVSP.creation_time = GetCurrentTimeStamp();
+    TVSP.update_time = GetCurrentTimeStamp();
+    TVSP.params.push_back({"label_name1", PropertyType::kString});
+    TVSP.params.push_back({"vid1", PropertyType::kInt32});
+    TVSP.params.push_back({"label_name2", PropertyType::kString});
+    TVSP.params.push_back({"vid2", PropertyType::kInt32});
+    TVSP.params.push_back({"label_name3", PropertyType::kString});
+    TVSP.params.push_back({"vid3", PropertyType::kInt32});
+    TVSP.returns.push_back({"TVSP", PropertyType::kString});
+    initialized = true;
+    builtin_plugins.push_back(TVSP);
+
+    initialized = true;
   }
   return builtin_plugins;
 }