diff --git a/app/src/main/java/be/ugent/sel/studeez/data/local/models/Friendship.kt b/app/src/main/java/be/ugent/sel/studeez/data/local/models/Friendship.kt
new file mode 100644
index 0000000..98aa9a5
--- /dev/null
+++ b/app/src/main/java/be/ugent/sel/studeez/data/local/models/Friendship.kt
@@ -0,0 +1,11 @@
+package be.ugent.sel.studeez.data.local.models
+
+import com.google.firebase.Timestamp
+import com.google.firebase.firestore.DocumentId
+
+data class Friendship(
+    @DocumentId val id: String = "",
+    val friendId: String = "",
+    val friendsSince: Timestamp = Timestamp.now(),
+    val accepted: Boolean = false
+)
\ No newline at end of file
diff --git a/app/src/main/java/be/ugent/sel/studeez/domain/FriendshipDAO.kt b/app/src/main/java/be/ugent/sel/studeez/domain/FriendshipDAO.kt
new file mode 100644
index 0000000..eda933d
--- /dev/null
+++ b/app/src/main/java/be/ugent/sel/studeez/domain/FriendshipDAO.kt
@@ -0,0 +1,48 @@
+package be.ugent.sel.studeez.domain
+
+import be.ugent.sel.studeez.data.local.models.Friendship
+import kotlinx.coroutines.flow.Flow
+
+/**
+ * Should be used for interactions between friends.
+ */
+interface FriendshipDAO {
+
+    /**
+     * @return all friendships of the user that is currently logged in.
+     */
+    fun getAllFriendships(): Flow<List<Friendship>>
+
+    /**
+     * @return the amount of friends of the currently logged in user.
+     * This method should be faster than just counting the length of getAllFriends()
+     */
+    fun getFriendshipCount(): Flow<Int>
+
+    /**
+     * @param id the id of the friendship that you want details of
+     * @return the details of a Friendship
+     */
+    fun getFriendshipDetails(id: String): Friendship
+
+    /**
+     * Send a friend request to a user.
+     * @param id of the user that you want to add as a friend
+     * @return Success/faillure of transaction
+     */
+    fun sendFriendshipRequest(id: String): Boolean
+
+    /**
+     * Accept a friend request that has already been sent.
+     * @param id of the friendship that you want to update
+     * @return: Success/faillure of transaction
+     */
+    fun acceptFriendship(id: String): Boolean
+
+    /**
+     * Remove a friend or decline a friendrequest.
+     * @param id of the friendship that you want to update
+     * @return: Success/faillure of transaction
+     */
+    fun removeFriendship(id: String): Boolean
+}
\ No newline at end of file
diff --git a/app/src/main/java/be/ugent/sel/studeez/domain/UserDAO.kt b/app/src/main/java/be/ugent/sel/studeez/domain/UserDAO.kt
index 619c77b..6017342 100644
--- a/app/src/main/java/be/ugent/sel/studeez/domain/UserDAO.kt
+++ b/app/src/main/java/be/ugent/sel/studeez/domain/UserDAO.kt
@@ -1,19 +1,44 @@
 package be.ugent.sel.studeez.domain
 
 import be.ugent.sel.studeez.data.local.models.User
+import kotlinx.coroutines.flow.Flow
 
 interface UserDAO {
 
-    suspend fun getUser(): User
+    /**
+     * @return all users
+     */
+    fun getAllUsers(): Flow<List<User>>
 
-    suspend fun saveUser(
+    /**
+     * @return all users based on a query, a trimmed down version of getAllUsers()
+     */
+    fun getUsersWithQuery(): Flow<List<User>>
+    // TODO Add query parameter
+
+    /**
+     * Request information about a user
+     */
+    fun getUserDetails(
+        userId: String
+    ): Flow<User>
+
+    /**
+     * @return information on the currently logged in user.
+     */
+    suspend fun getLoggedInUser(): User
+    // TODO Should be refactored to fun getLoggedInUser(): Flow<User>, without suspend.
+
+    suspend fun saveLoggedInUser(
         newUsername: String,
         newBiography: String = ""
     )
+    // TODO Should be refactored to fun saveLoggedInUser(...): Boolean, without suspend.
 
     /**
-     * Delete all references to this user in the database. Similar to the deleteCascade in
+     * Delete all references to the logged in user in the database. Similar to the deleteCascade in
      * relational databases.
      */
-    suspend fun deleteUserReferences()
+    suspend fun deleteLoggedInUserReferences()
+    // TODO Should be refactored to fun deleteLoggedInUserReferences(): Boolean, without suspend.
 }
\ No newline at end of file