diff --git a/backend/apis/nodejs/src/app.js b/backend/apis/nodejs/src/app.js
index bf803b9..3654f64 100644
--- a/backend/apis/nodejs/src/app.js
+++ b/backend/apis/nodejs/src/app.js
@@ -53,7 +53,8 @@ protectedRoutes.delete('/organization/post/:id', apiController.deleteOrganizatio
 app.use('/api', publicRoutes); // Routes not requiring token
 app.use('/api', protectedRoutes); // Routes requiring token
 
-// Start the server
-app.listen(process.env.API_SERVER_PORT, () => {
-  console.log(`Blink API server is running on port ${process.env.API_SERVER_PORT}`);
+// Start the server. Default port is 3000
+const port = process.env.API_SERVER_PORT || 3000;
+app.listen(port, () => {
+  console.log(`Blink API server is running on port ${port}`);
 });
\ No newline at end of file
diff --git a/backend/apis/nodejs/src/controllers/api_controller.js b/backend/apis/nodejs/src/controllers/api_controller.js
index b861190..e702a27 100644
--- a/backend/apis/nodejs/src/controllers/api_controller.js
+++ b/backend/apis/nodejs/src/controllers/api_controller.js
@@ -10,7 +10,7 @@
     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
     IN THE SOFTWARE.
 */
-
+// todo this file shall be deleted
 require('dotenv').config();
 const bcrypt = require('bcrypt');
 const crypto = require('crypto');
diff --git a/backend/apis/nodejs/src/routes/person_routes.js b/backend/apis/nodejs/src/routes/person_routes.js
index ab5c671..ee39e5f 100644
--- a/backend/apis/nodejs/src/routes/person_routes.js
+++ b/backend/apis/nodejs/src/routes/person_routes.js
@@ -1,8 +1,19 @@
-// Blink-specific modules
+/*
+    This code is part of Blink
+    licensed under GPLv3
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+    IMPLIED,  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+    IN THE SOFTWARE.
+*/
+
 const validator = require('../utils/validation');
 const knex = require('../utils/knex_config');
 const jwt_utils = require('../utils/jwt_utils');
-// Other modules
 const bcrypt = require('bcrypt');
 const crypto = require('crypto');
 
diff --git a/backend/apis/nodejs/src/utils/jwt_utils.js b/backend/apis/nodejs/src/utils/jwt_utils.js
index 73e48da..4d138fa 100644
--- a/backend/apis/nodejs/src/utils/jwt_utils.js
+++ b/backend/apis/nodejs/src/utils/jwt_utils.js
@@ -1,3 +1,16 @@
+/*
+    This code is part of Blink
+    licensed under GPLv3
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+    IMPLIED,  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+    IN THE SOFTWARE.
+*/
+
 const jwt = require('jsonwebtoken');
 
 function generateToken(person_id) {
diff --git a/backend/apis/nodejs/src/utils/knex_config.js b/backend/apis/nodejs/src/utils/knex_config.js
index 1b24831..25ac3cf 100644
--- a/backend/apis/nodejs/src/utils/knex_config.js
+++ b/backend/apis/nodejs/src/utils/knex_config.js
@@ -1,3 +1,16 @@
+/*
+    This code is part of Blink
+    licensed under GPLv3
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+    IMPLIED,  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+    IN THE SOFTWARE.
+*/
+
 const knexInstance = require('knex')({
     client: 'pg',
     connection: {
diff --git a/backend/apis/nodejs/src/utils/validation.js b/backend/apis/nodejs/src/utils/validation.js
index 071f325..4b6fc34 100644
--- a/backend/apis/nodejs/src/utils/validation.js
+++ b/backend/apis/nodejs/src/utils/validation.js
@@ -1,3 +1,16 @@
+/*
+    This code is part of Blink
+    licensed under GPLv3
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+    IMPLIED,  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+    IN THE SOFTWARE.
+*/
+
 /**
  * Checks whether an e-mail is in a valid format
  * @param {*} email email to validate