finish api basic setup

api/exceptions.py

@@ -0,0 +1,22 @@
+from flask import jsonify
+
+class ApiException(Exception):
+    status_code = 500
+
+    def __init__(self, status_code: int, message) -> None:
+        super().__init__()
+        self.status_code = status_code
+        self.message = message
+
+    def to_response(self):
+        rv = jsonify(self.message)
+        rv.status_code = self.status_code
+        return rv
+
+class NotFoundException(ApiException):
+    def __init__(self, message) -> None:
+        super().__init__(404, message)
+
+class BadRequestException(ApiException):
+    def __init__(self, message) -> None:
+        super().__init__(400, message)