diff --git a/internal/handlers/groups_handlers.go b/internal/handlers/groups_handlers.go
new file mode 100644
index 0000000..f8185cf
--- /dev/null
+++ b/internal/handlers/groups_handlers.go
@@ -0,0 +1,107 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"prak-03-todo/internal/db"
+	"strconv"
+
+	"github.com/gorilla/mux"
+)
+
+// CreateGroupHandler handles POST /groups
+func CreateGroupHandler(w http.ResponseWriter, r *http.Request) {
+	var groupRequest struct {
+		GroupName string `json:"group_name"`
+	}
+
+	err := json.NewDecoder(r.Body).Decode(&groupRequest)
+	if err != nil {
+		http.Error(w, "Invalid request body", http.StatusBadRequest)
+		return
+	}
+
+	// Validate input
+	if groupRequest.GroupName == "" {
+		http.Error(w, "Group name is required", http.StatusBadRequest)
+		return
+	}
+
+	// Create group using query function
+	group, err := db.CreateGroup(groupRequest.GroupName)
+	if err != nil {
+		http.Error(w, "Failed to create group", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusCreated)
+	json.NewEncoder(w).Encode(group)
+}
+
+// RemoveGroupHandler handles DELETE /groups/{groupId}
+func RemoveGroupHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	groupID, err := strconv.Atoi(vars["groupId"])
+	if err != nil {
+		http.Error(w, "Invalid group ID", http.StatusBadRequest)
+		return
+	}
+
+	// Delete group using query function
+	err = db.DeleteGroup(groupID)
+	if err != nil {
+		if err.Error() == "group not found" {
+			http.Error(w, "Group not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to delete group", http.StatusInternalServerError)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte("Group ID " + vars["groupId"] + " Removed"))
+}
+
+// GetGroupHandler handles GET /groups/{groupId}
+func GetGroupHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	groupID, err := strconv.Atoi(vars["groupId"])
+	if err != nil {
+		http.Error(w, "Invalid group ID", http.StatusBadRequest)
+		return
+	}
+
+	// Get group using query function
+	group, err := db.GetGroupByID(groupID)
+	if err != nil {
+		if err.Error() == "group not found" {
+			http.Error(w, "Group not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to fetch group", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(group)
+}
+
+// GetAllGroupsHandler handles GET /groups
+func GetAllGroupsHandler(w http.ResponseWriter, r *http.Request) {
+	groups, err := db.GetAllGroups()
+	if err != nil {
+		http.Error(w, "Failed to fetch groups", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(groups)
+}
+
+// Home handles GET /
+func Home(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Hello from Task Management API"))
+}
diff --git a/internal/handlers/tasks_handlers.go b/internal/handlers/tasks_handlers.go
new file mode 100644
index 0000000..cbf48a9
--- /dev/null
+++ b/internal/handlers/tasks_handlers.go
@@ -0,0 +1,223 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"prak-03-todo/internal/db"
+	"strconv"
+
+	"github.com/gorilla/mux"
+)
+
+// CreateTaskHandler handles POST /groups/{groupId}/tasks
+func CreateTaskHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	groupID, err := strconv.Atoi(vars["groupId"])
+	if err != nil {
+		http.Error(w, "Invalid group ID", http.StatusBadRequest)
+		return
+	}
+
+	var taskRequest struct {
+		TaskName        string  `json:"task_name"`
+		TaskDescription *string `json:"task_description,omitempty"`
+	}
+
+	err = json.NewDecoder(r.Body).Decode(&taskRequest)
+	if err != nil {
+		http.Error(w, "Invalid request body", http.StatusBadRequest)
+		return
+	}
+
+	// Validate input
+	if taskRequest.TaskName == "" {
+		http.Error(w, "Task name is required", http.StatusBadRequest)
+		return
+	}
+
+	// Verify group exists
+	_, err = db.GetGroupByID(groupID)
+	if err != nil {
+		if err.Error() == "group not found" {
+			http.Error(w, "Group not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to verify group", http.StatusInternalServerError)
+		return
+	}
+
+	// Create task using query function
+	task, err := db.CreateTask(taskRequest.TaskName, taskRequest.TaskDescription, groupID)
+	if err != nil {
+		http.Error(w, "Failed to create task", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusCreated)
+	json.NewEncoder(w).Encode(task)
+}
+
+// DisplayTasksHandler handles GET /tasks
+func DisplayTasksHandler(w http.ResponseWriter, r *http.Request) {
+	tasks, err := db.GetAllTasks()
+	if err != nil {
+		http.Error(w, "Failed to fetch tasks", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(tasks)
+}
+
+// DisplayTasksByGroupHandler handles GET /groups/{groupId}/tasks
+func DisplayTasksByGroupHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	groupID, err := strconv.Atoi(vars["groupId"])
+	if err != nil {
+		http.Error(w, "Invalid group ID", http.StatusBadRequest)
+		return
+	}
+
+	// Verify group exists
+	_, err = db.GetGroupByID(groupID)
+	if err != nil {
+		if err.Error() == "group not found" {
+			http.Error(w, "Group not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to verify group", http.StatusInternalServerError)
+		return
+	}
+
+	// Get tasks for the group
+	tasks, err := db.GetTasksByGroupID(groupID)
+	if err != nil {
+		http.Error(w, "Failed to fetch tasks", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(tasks)
+}
+
+// GetTaskHandler handles GET /tasks/{taskId}
+func GetTaskHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	taskID, err := strconv.Atoi(vars["taskId"])
+	if err != nil {
+		http.Error(w, "Invalid task ID", http.StatusBadRequest)
+		return
+	}
+
+	task, err := db.GetTaskByID(taskID)
+	if err != nil {
+		if err.Error() == "task not found" {
+			http.Error(w, "Task not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to fetch task", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(task)
+}
+
+// UpdateTaskHandler handles PUT /tasks/{taskId}
+func UpdateTaskHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	taskID, err := strconv.Atoi(vars["taskId"])
+	if err != nil {
+		http.Error(w, "Invalid task ID", http.StatusBadRequest)
+		return
+	}
+
+	var taskRequest struct {
+		TaskName        string  `json:"task_name"`
+		TaskDescription *string `json:"task_description,omitempty"`
+	}
+
+	err = json.NewDecoder(r.Body).Decode(&taskRequest)
+	if err != nil {
+		http.Error(w, "Invalid request body", http.StatusBadRequest)
+		return
+	}
+
+	// Validate input
+	if taskRequest.TaskName == "" {
+		http.Error(w, "Task name is required", http.StatusBadRequest)
+		return
+	}
+
+	// Update task using query function
+	err = db.UpdateTask(taskID, taskRequest.TaskName, taskRequest.TaskDescription)
+	if err != nil {
+		if err.Error() == "task not found" {
+			http.Error(w, "Task not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to update task", http.StatusInternalServerError)
+		return
+	}
+
+	// Get updated task
+	task, err := db.GetTaskByID(taskID)
+	if err != nil {
+		http.Error(w, "Failed to fetch updated task", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(task)
+}
+
+// MarkTaskDoneHandler handles PUT /tasks/{taskId}/done
+func MarkTaskDoneHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	taskID, err := strconv.Atoi(vars["taskId"])
+	if err != nil {
+		http.Error(w, "Invalid task ID", http.StatusBadRequest)
+		return
+	}
+
+	err = db.MarkTaskDone(taskID)
+	if err != nil {
+		if err.Error() == "task not found" {
+			http.Error(w, "Task not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to mark task as done", http.StatusInternalServerError)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte("Task ID " + vars["taskId"] + " Marked as Done"))
+}
+
+// RemoveTaskHandler handles DELETE /tasks/{taskId}
+func RemoveTaskHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	taskID, err := strconv.Atoi(vars["taskId"])
+	if err != nil {
+		http.Error(w, "Invalid task ID", http.StatusBadRequest)
+		return
+	}
+
+	err = db.DeleteTask(taskID)
+	if err != nil {
+		if err.Error() == "task not found" {
+			http.Error(w, "Task not found", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "Failed to delete task", http.StatusInternalServerError)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte("Task ID " + vars["taskId"] + " Removed"))
+}