diff --git a/src/main/java/eu/openaire/urls_controller/controllers/UrlController.java b/src/main/java/eu/openaire/urls_controller/controllers/UrlController.java
index 14a6c94..15d0d1c 100644
--- a/src/main/java/eu/openaire/urls_controller/controllers/UrlController.java
+++ b/src/main/java/eu/openaire/urls_controller/controllers/UrlController.java
@@ -35,8 +35,9 @@ public class UrlController {
         List<Task> tasks = new ArrayList<>();
 
         // TODO - Create the Assignment from the id-urls stored in the database up to the tasks-limit.
+        int assignmentId = 0;
 
-        Assignment assignment = new Assignment(tasks, workerId, new Date());
+        Assignment assignment = new Assignment(assignmentId, tasks, workerId, new Date());
 
         // TODO - Write the Assignment details to the database and then send it to the worker.
 
@@ -44,6 +45,8 @@ public class UrlController {
     }
 
 
+    private static int assignmentId = -1;    // Just for the "getTestUrls"-endpoint.
+
     @GetMapping("test")
     public ResponseEntity<?> getTestUrls(@RequestParam String workerId, @RequestParam int tasksLimit) {
 
@@ -84,7 +87,7 @@ public class UrlController {
 
         }// end loading-while-loop
 
-        Assignment assignment = new Assignment(tasks, workerId, new Date());
+        Assignment assignment = new Assignment((++assignmentId), tasks, workerId, new Date());
 
         return ResponseEntity.status(200).header("Content-Type", "application/json").body(new AssignmentResponse(assignment));
     }
diff --git a/src/main/java/eu/openaire/urls_controller/models/Assignment.java b/src/main/java/eu/openaire/urls_controller/models/Assignment.java
index bd5b216..006779f 100644
--- a/src/main/java/eu/openaire/urls_controller/models/Assignment.java
+++ b/src/main/java/eu/openaire/urls_controller/models/Assignment.java
@@ -10,12 +10,16 @@ import java.util.List;
 
 @JsonInclude(JsonInclude.Include.NON_NULL)
 @JsonPropertyOrder({
+        "assignmentId",
         "tasks",
         "workerId",
         "date"
 })
 public class Assignment {
 
+    @JsonProperty("assignmentId")
+    private int assignmentId;
+
     @JsonProperty("tasks")
     private List<Task> tasks;
 
@@ -25,12 +29,21 @@ public class Assignment {
     @JsonProperty("date")
     private Date date;
 
-    public Assignment(List<Task> tasks, String workerId, Date date) {
+    public Assignment(int assignmentId, List<Task> tasks, String workerId, Date date) {
+        this.assignmentId = assignmentId;
         this.tasks = tasks;
         this.workerId = workerId;
         this.date = date;
     }
 
+    public int getAssignmentId() {
+        return assignmentId;
+    }
+
+    public void setAssignmentId(int assignmentId) {
+        this.assignmentId = assignmentId;
+    }
+
     public List<Task> getTasks() {
         return tasks;
     }
@@ -58,7 +71,8 @@ public class Assignment {
     @Override
     public String toString() {
         return "Assignment{" +
-                "tasks=" + tasks +
+                "assignmentId=" + assignmentId +
+                ", tasks=" + tasks +
                 ", workerId='" + workerId + '\'' +
                 ", date=" + date +
                 '}';