diff --git a/src/main/java/eu/openaire/urls_controller/models/Payload.java b/src/main/java/eu/openaire/urls_controller/models/Payload.java
index f857cb8..55377ec 100644
--- a/src/main/java/eu/openaire/urls_controller/models/Payload.java
+++ b/src/main/java/eu/openaire/urls_controller/models/Payload.java
@@ -4,6 +4,8 @@ import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
+import java.util.Date;
+
 
 @JsonInclude(JsonInclude.Include.NON_NULL)
 @JsonPropertyOrder({
@@ -14,7 +16,7 @@ import com.fasterxml.jackson.annotation.JsonPropertyOrder;
         "mime_type",
         "size",
         "more_info",
-        "hash",
+        "md5",
         "location",
         "provenance"
 })
@@ -27,22 +29,22 @@ public class Payload {
     private String original_url;
 
     @JsonProperty("actual_url")
-    private String actual_url;  // The url of the full-text itself.
+    private String actual_url;
 
     @JsonProperty("date_acquired")
-    private String date_acquired;
+    private Date date_acquired;
 
     @JsonProperty("mime_type")
     private String mime_type;
 
     @JsonProperty("size")
-    private String size;
+    private Long size;  // In bytes.
 
     @JsonProperty("more_info")
     private  String more_info;
 
-    @JsonProperty("hash")
-    private String hash;
+    @JsonProperty("md5")
+    private String md5;
 
     @JsonProperty("location")
     private String location;
@@ -51,6 +53,19 @@ public class Payload {
     private String provenance;
 
 
+    public Payload(String id, String original_url, String actual_url, Date date_acquired, String mime_type, Long size, String more_info, String md5, String location, String provenance) {
+        this.id = id;
+        this.original_url = original_url;
+        this.actual_url = actual_url;
+        this.date_acquired = date_acquired;
+        this.mime_type = mime_type;
+        this.size = size;
+        this.more_info = more_info;
+        this.md5 = md5;
+        this.location = location;
+        this.provenance = provenance;
+    }
+
     public String getId() {
         return id;
     }
@@ -75,11 +90,11 @@ public class Payload {
         this.actual_url = actual_url;
     }
 
-    public String getDate_acquired() {
+    public Date getDate_acquired() {
         return date_acquired;
     }
 
-    public void setDate_acquired(String date_acquired) {
+    public void setDate_acquired(Date date_acquired) {
         this.date_acquired = date_acquired;
     }
 
@@ -91,11 +106,11 @@ public class Payload {
         this.mime_type = mime_type;
     }
 
-    public String getSize() {
+    public Long getSize() {
         return size;
     }
 
-    public void setSize(String size) {
+    public void setSize(Long size) {
         this.size = size;
     }
 
@@ -107,12 +122,12 @@ public class Payload {
         this.more_info = more_info;
     }
 
-    public String getHash() {
-        return hash;
+    public String getMd5() {
+        return md5;
     }
 
-    public void setHash(String hash) {
-        this.hash = hash;
+    public void setMd5(String md5) {
+        this.md5 = md5;
     }
 
     public String getLocation() {
@@ -141,7 +156,7 @@ public class Payload {
                 ", mime_type='" + mime_type + '\'' +
                 ", size='" + size + '\'' +
                 ", more_info='" + more_info + '\'' +
-                ", hash='" + hash + '\'' +
+                ", md5='" + md5 + '\'' +
                 ", location='" + location + '\'' +
                 ", provenance='" + provenance + '\'' +
                 '}';
diff --git a/src/main/java/eu/openaire/urls_controller/models/UrlReport.java b/src/main/java/eu/openaire/urls_controller/models/UrlReport.java
index 4645938..da95163 100644
--- a/src/main/java/eu/openaire/urls_controller/models/UrlReport.java
+++ b/src/main/java/eu/openaire/urls_controller/models/UrlReport.java
@@ -7,42 +7,30 @@ import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 @JsonInclude(JsonInclude.Include.NON_NULL)
 @JsonPropertyOrder({
-        "task",
         "status",
         "payload"
 })
 public class UrlReport {
 
-    @JsonProperty("task")
-    private Task task;
-
     @JsonProperty("status")
-    private String Status;
+    private String status;
 
     @JsonProperty("payload")
     private Payload payload;
 
 
-    public UrlReport(Task task, String status, Payload payload) {
-        this.task = task;
-        Status = status;
+    public UrlReport(String status, Payload payload) {
+        this.status = status;
         this.payload = payload;
     }
 
-    public Task getTask() {
-        return task;
-    }
-
-    public void setTask(Task task) {
-        this.task = task;
-    }
 
     public String getStatus() {
-        return Status;
+        return this.status;
     }
 
     public void setStatus(String status) {
-        Status = status;
+        this.status = status;
     }
 
     public Payload getPayload() {
@@ -52,4 +40,12 @@ public class UrlReport {
     public void setPayload(Payload payload) {
         this.payload = payload;
     }
+
+    @Override
+    public String toString() {
+        return "UrlReport{" +
+                "status='" + status + '\'' +
+                ", payload=" + payload +
+                '}';
+    }
 }
diff --git a/src/main/java/eu/openaire/urls_controller/payloads/requests/WorkerReport.java b/src/main/java/eu/openaire/urls_controller/payloads/requests/WorkerReport.java
index df32abf..23f9a5f 100644
--- a/src/main/java/eu/openaire/urls_controller/payloads/requests/WorkerReport.java
+++ b/src/main/java/eu/openaire/urls_controller/payloads/requests/WorkerReport.java
@@ -11,6 +11,7 @@ import java.util.List;
 @JsonInclude(JsonInclude.Include.NON_NULL)
 @JsonPropertyOrder({
         "workerId",
+        "assignmentId",
         "urlReports"
 })
 public class WorkerReport {
@@ -18,11 +19,15 @@ public class WorkerReport {
     @JsonProperty("workerId")
     private String workerId;
 
+    @JsonProperty("assignmentId")
+    private int assignmentId;
+
     @JsonProperty("urlReports")
     private List<UrlReport> urlReports;
 
-    public WorkerReport(String workerId, List<UrlReport> urlReports) {
+    public WorkerReport(String workerId, int assignmentId, List<UrlReport> urlReports) {
         this.workerId = workerId;
+        this.assignmentId = assignmentId;
         this.urlReports = urlReports;
     }
 
@@ -34,6 +39,14 @@ public class WorkerReport {
         this.workerId = workerId;
     }
 
+    public int getAssignmentId() {
+        return this.assignmentId;
+    }
+
+    public void setAssignmentId(int assignmentId) {
+        this.assignmentId = assignmentId;
+    }
+
     public List<UrlReport> getUrlReports() {
         return this.urlReports;
     }
@@ -41,4 +54,13 @@ public class WorkerReport {
     public void setUrlReports(List<UrlReport> urlReports) {
         this.urlReports = urlReports;
     }
+
+    @Override
+    public String toString() {
+        return "WorkerReport{" +
+                "workerId='" + workerId + '\'' +
+                ", assignmentId=" + assignmentId +
+                ", urlReports=" + urlReports +
+                '}';
+    }
 }