diff --git a/apps/cli/pisa_cli.py b/apps/cli/pisa_cli.py
index c793b96..0f2eb92 100644
--- a/apps/cli/pisa_cli.py
+++ b/apps/cli/pisa_cli.py
@@ -21,6 +21,7 @@ from apps.cli import (
 )
 
 from common.logger import Logger
+from common.appointment import Appointment
 from common.constants import LOCATOR_LEN_HEX
 from common.cryptographer import Cryptographer
 from common.tools import check_sha256_hex_format
@@ -128,13 +129,7 @@ def add_appointment(args):
         return False
 
     add_appointment_endpoint = "http://{}:{}".format(pisa_api_server, pisa_api_port)
-    appointment = build_appointment(
-        appointment_data.get("tx"),
-        appointment_data.get("tx_id"),
-        appointment_data.get("start_time"),
-        appointment_data.get("end_time"),
-        appointment_data.get("to_self_delay"),
-    )
+    appointment = Appointment.from_dict(appointment_data)
 
     try:
         sk_der = load_key_file_data(CLI_PRIVATE_KEY)
@@ -152,7 +147,7 @@ def add_appointment(args):
         logger.error("I/O error", errno=e.errno, error=e.strerror)
         return False
 
-    signature = Cryptographer.sign(Cryptographer.signature_format(appointment), cli_sk)
+    signature = Cryptographer.sign(appointment.serialize(), cli_sk)
 
     try:
         cli_pk_der = load_key_file_data(CLI_PUBLIC_KEY)
@@ -217,7 +212,7 @@ def add_appointment(args):
             logger.error("Failed to deserialize the public key. It might be in an unsupported format")
             return False
 
-        is_sig_valid = Cryptographer.verify(Cryptographer.signature_format(appointment), signature, pisa_pk)
+        is_sig_valid = Cryptographer.verify(appointment.serialize(), signature, pisa_pk)
 
     except FileNotFoundError:
         logger.error("Pisa's public key file not found. Please check your settings")
@@ -278,24 +273,6 @@ def get_appointment(args):
     return True
 
 
-def build_appointment(tx, tx_id, start_time, end_time, to_self_delay):
-    locator = compute_locator(tx_id)
-
-    # FIXME: The blob data should contain more things that just the transaction. Leaving like this for now.
-    blob = Blob(tx)
-    encrypted_blob = Cryptographer.encrypt(blob, tx_id)
-
-    appointment = {
-        "locator": locator,
-        "start_time": start_time,
-        "end_time": end_time,
-        "to_self_delay": to_self_delay,
-        "encrypted_blob": encrypted_blob,
-    }
-
-    return appointment
-
-
 def show_usage():
     return (
         "USAGE: "
diff --git a/pisa/api.py b/pisa/api.py
index 2659e94..f0ec6ae 100644
--- a/pisa/api.py
+++ b/pisa/api.py
@@ -5,7 +5,7 @@ from flask import Flask, request, abort, jsonify
 from pisa import HOST, PORT, logging
 from common.logger import Logger
 from pisa.inspector import Inspector
-from pisa.appointment import Appointment
+from common.appointment import Appointment
 from pisa.block_processor import BlockProcessor
 
 from common.constants import HTTP_OK, HTTP_BAD_REQUEST, HTTP_SERVICE_UNAVAILABLE, LOCATOR_LEN_HEX
diff --git a/pisa/builder.py b/pisa/builder.py
index 063cb98..6f0f2bf 100644
--- a/pisa/builder.py
+++ b/pisa/builder.py
@@ -1,7 +1,7 @@
 from queue import Queue
 
 from pisa.responder import TransactionTracker
-from pisa.appointment import Appointment
+from common.appointment import Appointment
 
 
 class Builder:
diff --git a/pisa/inspector.py b/pisa/inspector.py
index 54174cb..00a7fc2 100644
--- a/pisa/inspector.py
+++ b/pisa/inspector.py
@@ -7,7 +7,7 @@ from common.cryptographer import Cryptographer
 from pisa import errors
 import pisa.conf as conf
 from common.logger import Logger
-from pisa.appointment import Appointment
+from common.appointment import Appointment
 from pisa.block_processor import BlockProcessor
 
 logger = Logger("Inspector")
@@ -309,12 +309,12 @@ class Inspector:
 
     @staticmethod
     # Verifies that the appointment signature is a valid signature with public key
-    def check_appointment_signature(appointment, signature, pk_der):
+    def check_appointment_signature(appointment_data, signature, pk_der):
         """
         Checks if the provided user signature is correct.
 
         Args:
-            appointment (:obj:`dict`): the appointment that was signed by the user.
+            appointment_data (:obj:`dict`): the appointment that was signed by the user.
             signature (:obj:`str`): the user's signature (hex encoded).
             pk_der (:obj:`str`): the user's public key (hex encoded, DER format).
 
@@ -336,7 +336,7 @@ class Inspector:
             message = "empty signature received"
 
         pk = Cryptographer.load_public_key_der(unhexlify(pk_der))
-        valid_sig = Cryptographer.verify(Cryptographer.signature_format(appointment), signature, pk)
+        valid_sig = Cryptographer.verify(Appointment.from_dict(appointment_data).serialize(), signature, pk)
 
         if not valid_sig:
             rcode = errors.APPOINTMENT_INVALID_SIGNATURE
diff --git a/pisa/watcher.py b/pisa/watcher.py
index 5079050..9d659db 100644
--- a/pisa/watcher.py
+++ b/pisa/watcher.py
@@ -141,7 +141,7 @@ class Watcher:
 
             logger.info("New appointment accepted", locator=appointment.locator)
 
-            signature = Cryptographer.sign(Cryptographer.signature_format(appointment.to_dict()), self.signing_key)
+            signature = Cryptographer.sign(appointment.serialize(), self.signing_key)
 
         else:
             appointment_added = False