diff --git a/buisnesslogic/src/main/java/com/plannaplan/entities/Assignment.java b/buisnesslogic/src/main/java/com/plannaplan/entities/Assignment.java
index 2f0722b..429d482 100755
--- a/buisnesslogic/src/main/java/com/plannaplan/entities/Assignment.java
+++ b/buisnesslogic/src/main/java/com/plannaplan/entities/Assignment.java
@@ -47,6 +47,14 @@ public class Assignment {
         return this.group.getRegisteredStudents().contains(this.commision.getCommisionOwner());
     }
 
+    /** 
+     * Getter of commision
+     * @return Commision Commision of given assignments
+     */
+    public Commision getCommision(){
+        return this.commision;
+    }
+
     /**
      * Assignment
      * 
diff --git a/buisnesslogic/src/main/java/com/plannaplan/entities/Exchange.java b/buisnesslogic/src/main/java/com/plannaplan/entities/Exchange.java
index 37b7111..785c681 100644
--- a/buisnesslogic/src/main/java/com/plannaplan/entities/Exchange.java
+++ b/buisnesslogic/src/main/java/com/plannaplan/entities/Exchange.java
@@ -7,6 +7,9 @@ import javax.persistence.Id;
 import javax.persistence.JoinColumn;
 import javax.persistence.OneToOne;
 
+/**
+ *  Entity that keeps user exchange offer. 
+ */
 @Entity
 public class Exchange {
 
@@ -14,10 +17,6 @@ public class Exchange {
     @GeneratedValue(strategy = GenerationType.AUTO)
     private Long id;
 
-    @OneToOne
-    @JoinColumn(name = "trader_id")
-    private User trader;
-
     @OneToOne
     @JoinColumn(name = "owned_id")
     private Assignment ownedAssignment;
@@ -30,38 +29,48 @@ public class Exchange {
 
     }
 
-    public Exchange(User trader, Assignment ownedAssignment, Groups desiredAssignment){
-        this.trader = trader;
+    public Exchange(Assignment ownedAssignment, Groups desiredAssignment){
         this.ownedAssignment = ownedAssignment;
         this.desiredAssignment = desiredAssignment;
     }
 
+    
+    /** 
+     * @return Long ID in database
+     */
     public Long getId(){
         return this.id;
     }
 
+    
+    /** 
+     * @return Groups Target group
+     */
     public Groups getDesiredAssignment() {
         return desiredAssignment;
     }
 
+    
+    /** 
+     * @param desiredAssignment Target group
+     */
     public void setDesiredAssignment(Groups desiredAssignment) {
         this.desiredAssignment = desiredAssignment;
     }
 
+    
+    /** 
+     * @return Assignment Owned assignment
+     */
     public Assignment getOwnedAssignment() {
         return ownedAssignment;
     }
 
+    
+    /** 
+     * @param ownedAssignment Owned assignment
+     */
     public void setOwnedAssignment(Assignment ownedAssignment) {
         this.ownedAssignment = ownedAssignment;
     }
-
-    public User getTrader() {
-        return trader;
-    }
-
-    public void setTrader(User trader) {
-        this.trader = trader;
-    }
-
-}
+}
\ No newline at end of file
diff --git a/buisnesslogic/src/main/java/com/plannaplan/services/ExchangeService.java b/buisnesslogic/src/main/java/com/plannaplan/services/ExchangeService.java
index 59d8002..8cd7bb0 100644
--- a/buisnesslogic/src/main/java/com/plannaplan/services/ExchangeService.java
+++ b/buisnesslogic/src/main/java/com/plannaplan/services/ExchangeService.java
@@ -12,6 +12,10 @@ public class ExchangeService {
     @Autowired
     private ExchangeRepository repo;
 
+    /** 
+     * @param exchange Instance to save in database
+     * @return Exchange Instance contains database id
+     */
     public Exchange save(Exchange exchange){
         return this.repo.save(exchange);
     }
diff --git a/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java b/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
index 5c775cc..719f33c 100644
--- a/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
+++ b/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
@@ -8,11 +8,10 @@ import com.plannaplan.entities.Assignment;
 import com.plannaplan.entities.Exchange;
 import com.plannaplan.entities.Groups;
 import com.plannaplan.entities.User;
-import com.plannaplan.repositories.ExchangeRepository;
+import com.plannaplan.exceptions.UserNotFoundException;
 import com.plannaplan.services.AssignmentService;
 import com.plannaplan.services.ExchangeService;
 import com.plannaplan.services.GroupService;
-import com.plannaplan.services.UserService;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
@@ -30,10 +29,13 @@ import io.swagger.annotations.ApiOperation;
 @CrossOrigin
 @RequestMapping("/api/" + App.API_VERSION + "/exchanges")
 @Api(tags = { "Exchange" }, value = "Exchange", description = "Endpoint to exchange with accepted assignments.")
-public class ExchangeController {
+public class ExchangeController extends TokenBasedController{
   
-    @Autowired
-    private UserService userService;
+
+    /*
+        * Endpoint do wylistowania exchangow użytkownika
+        * Endpoint do usuwania exchanga 
+    */
 
     @Autowired
     private GroupService groupService;
@@ -46,28 +48,33 @@ public class ExchangeController {
 
     @PostMapping("/exchange")
     @ApiOperation(value = "Return all courses")
-    public ResponseEntity<String> createExchange(@RequestBody Map<String, Long> exchangeRequest){
+    public ResponseEntity<String> createExchange(@RequestBody Map<String, Long> exchangeRequest)
+            throws UserNotFoundException {
 
-        final Long userId = exchangeRequest.get("user");
+        final User asker = this.getCurrentUser()
+                                        .orElseThrow(() -> new UserNotFoundException("Invalid token"));
         final Long assignmentId = exchangeRequest.get("assignment");
         final Long groupId = exchangeRequest.get("group");
 
-        if(userId == null || assignmentId == null|| groupId == null ){
+        if(assignmentId == null || groupId == null ){
             return new ResponseEntity<>("Some of values are missing", HttpStatus.BAD_REQUEST);
         }
 
-        final Optional<User> user = this.userService.getById(userId);
         final Optional<Assignment> assignment = this.assignmentService.getById(assignmentId);
         final Optional<Groups> group = this.groupService.getGroupById(groupId);
         
-        if(user.isEmpty() || assignment.isEmpty() || group.isEmpty()){
+        if(assignment.isEmpty() || group.isEmpty()){
             return new ResponseEntity<>("Some of provided value does not exist.", HttpStatus.BAD_REQUEST);
         }
 
-        this.exchangeService.save(new Exchange(user.get(), assignment.get(), group.get()));
+        final Assignment assignmentInstance = assignment.get();
 
-        //System.out.println("KUPA");
+        if(!(assignmentInstance.getCommision().getCommisionOwner().getId() == asker.getId() && assignmentInstance.isAccepted())){
+            return new ResponseEntity<>("Some of problems appeared. Check if you have access to given assignment and if it is accepted", HttpStatus.BAD_REQUEST);
+        }
 
-        return null;
+        this.exchangeService.save(new Exchange(assignment.get(), group.get()));
+
+        return new ResponseEntity<>("Success", HttpStatus.OK);
     }
 }