diff --git a/src/main/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchive.java b/src/main/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchive.java
index e69de29..c09cec6 100644
--- a/src/main/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchive.java
+++ b/src/main/java/edu/ntnu/idi/idatt2003/g40/mappe/TransactionArchive.java
@@ -0,0 +1,101 @@
+package edu.ntnu.idi.idatt2003.g40.mappe;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Stores completed transactions.
+ */
+public class TransactionArchive {
+
+    private final List<Transaction> transactions = new ArrayList<>();
+
+    /**
+     * Creates an empty transaction archive.
+     */
+    public TransactionArchive() {
+    }
+
+    /**
+     * Adds a transaction to the archive.
+     *
+     * @param transaction the transaction to add
+     * @return true if the transaction was added
+     */
+    public boolean add(Transaction transaction) {
+        return transactions.add(transaction);
+    }
+
+    /**
+     * Checks whether the archive is empty.
+     *
+     * @return true if no transactions exist
+     */
+    public boolean isEmpty() {
+        return transactions.isEmpty();
+    }
+
+    /**
+     * Returns all transactions from a given week.
+     *
+     * @param week the week number
+     * @return list of transactions from the given week
+     */
+    public List<Transaction> getTransactions(int week) {
+        List<Transaction> result = new ArrayList<>();
+        for (Transaction transaction : transactions) {
+            if (transaction.getWeek() == week) {
+                result.add(transaction);
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Returns all purchase transactions from a given week.
+     *
+     * @param week the week number
+     * @return list of purchases from the given week
+     */
+    public List<Purchase> getPurchases(int week) {
+        List<Purchase> result = new ArrayList<>();
+        for (Transaction transaction : transactions) {
+            if (transaction instanceof Purchase purchase && transaction.getWeek() == week) {
+                result.add(purchase);
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Returns all sale transactions from a given week.
+     *
+     * @param week the week number
+     * @return list of sales from the given week
+     */
+    public List<Sale> getSales(int week) {
+        List<Sale> result = new ArrayList<>();
+        for (Transaction transaction : transactions) {
+            if (transaction instanceof Sale sale && transaction.getWeek() == week) {
+                result.add(sale);
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Counts the number of distinct weeks with transactions.
+     *
+     * @return number of distinct weeks
+     */
+    public int countDistinctWeeks() {
+        List<Integer> weeks = new ArrayList<>();
+        for (Transaction transaction : transactions) {
+            int week = transaction.getWeek();
+            if (!weeks.contains(week)) {
+                weeks.add(week);
+            }
+        }
+        return weeks.size();
+    }
+}
\ No newline at end of file