diff --git a/apps/cli/__init__.py b/apps/cli/__init__.py
index 59bcde7..db1f620 100644
--- a/apps/cli/__init__.py
+++ b/apps/cli/__init__.py
@@ -2,7 +2,7 @@ import logging
 from .logger import Logger
 
 # PISA-SERVER
-DEFAULT_PISA_API_SERVER = 'btc.pisa.watch'
+DEFAULT_PISA_API_SERVER = 'localhost'
 DEFAULT_PISA_API_PORT = 9814
 
 # PISA-CLI
diff --git a/apps/cli/logger.py b/apps/cli/logger.py
index 08c2547..1b3f4d3 100644
--- a/apps/cli/logger.py
+++ b/apps/cli/logger.py
@@ -30,4 +30,4 @@ class Logger(object):
         logging.error(StructuredMessage(self._add_prefix(msg), actor=self.actor, **kwargs))
 
     def warning(self, msg, **kwargs):
-        logging.warning(StructuredMessage(self._add_prefix(msg), actor=self.actor, **kwargs))
\ No newline at end of file
+        logging.warning(StructuredMessage(self._add_prefix(msg), actor=self.actor, **kwargs))
diff --git a/apps/cli/pisa-cli.py b/apps/cli/pisa-cli.py
index 0a56f1d..4d22ee7 100644
--- a/apps/cli/pisa-cli.py
+++ b/apps/cli/pisa-cli.py
@@ -67,12 +67,13 @@ def is_appointment_signature_valid(appointment, signature):
     return True
 
 
+# Makes sure that the folder APPOINTMENTS_FOLDER_NAME exists, then saves the appointment and signature in it.
 def save_signed_appointment(appointment, signature):
     # Create the appointments directory if it doesn't already exist
     try:
         os.makedirs(APPOINTMENTS_FOLDER_NAME)
     except FileExistsError:
-        # directory already exists
+        # directory already exists, this is fine
         pass
 
     timestamp = int(time.time()*1000)
@@ -127,41 +128,56 @@ def add_appointment(args):
                     r = requests.post(url=add_appointment_endpoint, json=appointment_json, timeout=5)
 
                     response_json = r.json()
-                    print(response_json)
-
-                    if r.status_code == HTTP_OK:
-                        if 'signature' not in response_json:
-                            logger.error("The response does not contain the signature of the appointment.")
-                        else:
-                            signature = response_json['signature']
-                            # verify that the returned signature is valid
-                            if is_appointment_signature_valid(appointment, signature):
-                                logger.info("Appointment accepted and signed by Pisa.")
-                                # TODO: store on disk
-                                save_signed_appointment(appointment, signature)
-                            else:
-                                logger.error("The returned appointment's signature is invalid.")
-                    else:
-                        if 'error' not in response_json:
-                            logger.error("The server returned status code {}, but no error description."
-                                         .format(r.status_code))
-                        else:
-                            error = r.json()['error']
-                            logger.error("The server returned status code {}, and the following error: {}."
-                                         .format(r.status_code, error))
 
                 except json.JSONDecodeError:
                     logger.error("The response was not valid JSON.")
+                    return
 
                 except ConnectTimeout:
                     logger.error("Can't connect to pisa API. Connection timeout.")
+                    return
 
                 except ConnectionError:
                     logger.error("Can't connect to pisa API. Server cannot be reached.")
-                except FileNotFoundError:
-                    logger.error("Pisa's public key file not found. Please check your settings.")
-                except IOError as e:
-                    logger.error("I/O error({}): {}".format(e.errno, e.strerror))
+                    return
+
+                if r.status_code == HTTP_OK:
+                    if 'signature' not in response_json:
+                        logger.error("The response does not contain the signature of the appointment.")
+                    else:
+                        signature = response_json['signature']
+                        # verify that the returned signature is valid
+                        try:
+                            is_sig_valid = is_appointment_signature_valid(appointment, signature)
+                        except ValueError:
+                            logger.error("Failed to deserialize the public key. It might be in an unsupported format.")
+                            return
+                        except FileNotFoundError:
+                            logger.error("Pisa's public key file not found. Please check your settings.")
+                            return
+                        except IOError as e:
+                            logger.error("I/O error({}): {}".format(e.errno, e.strerror))
+                            return
+
+                        if is_sig_valid:
+                            logger.info("Appointment accepted and signed by Pisa.")
+                            # all good, store appointment and signature
+                            try:
+                                save_signed_appointment(appointment, signature)
+                            except OSError as e:
+                                logger.error("There was an error while saving the appointment: {}".format(e))
+                        else:
+                            logger.error("The returned appointment's signature is invalid.")
+
+                else:
+                    if 'error' not in response_json:
+                        logger.error("The server returned status code {}, but no error description."
+                                     .format(r.status_code))
+                    else:
+                        error = r.json()['error']
+                        logger.error("The server returned status code {}, and the following error: {}."
+                                     .format(r.status_code, error))
+
             else:
                 logger.error("The provided locator is not valid.")
     else:
diff --git a/pisa/watcher.py b/pisa/watcher.py
index 0a8da57..ef80865 100644
--- a/pisa/watcher.py
+++ b/pisa/watcher.py
@@ -46,8 +46,6 @@ class Watcher:
         # If the watcher is awake, every new appointment will just be added to the appointment list until
         # max_appointments is reached.
 
-        signature = None
-
         if len(self.appointments) < self.max_appointments:
             # Appointments are identified by the locator: the sha256 of commitment txid (H(tx_id)).
             # Two different nodes may ask for appointments using the same commitment txid, what will result in a
@@ -80,6 +78,7 @@ class Watcher:
             signature = self.sign_appointment(appointment)
         else:
             appointment_added = False
+            signature = None
 
             logger.info("Maximum appointments reached, appointment rejected.", locator=appointment.locator)