diff --git a/polyapi/cli.py b/polyapi/cli.py
index 66dd234..af5ab46 100644
--- a/polyapi/cli.py
+++ b/polyapi/cli.py
@@ -2,7 +2,7 @@
 
 from polyapi.utils import print_green
 
-from .config import clear_config, set_api_key_and_url
+from .config import initialize_config, set_api_key_and_url
 from .generate import generate, clear
 from .function_cli import function_add_or_update, function_execute
 from .rendered_spec import get_and_update_rendered_spec
@@ -43,7 +43,7 @@ def execute_from_cli() -> None:
     elif command == "setup" and len(args.subcommands) == 2:
         set_api_key_and_url(args.subcommands[1], args.subcommands[0])
     elif command == "setup":
-        clear_config()
+        initialize_config(force=True)
         generate()
     elif command == "update_rendered_spec":
         assert len(args.subcommands) == 1
diff --git a/polyapi/config.py b/polyapi/config.py
index 5e0e143..19016f5 100644
--- a/polyapi/config.py
+++ b/polyapi/config.py
@@ -3,6 +3,8 @@
 import configparser
 from typing import Tuple
 
+from polyapi.utils import is_valid_polyapi_url, is_valid_uuid, print_green, print_yellow
+
 # cached values
 API_KEY = None
 API_URL = None
@@ -55,18 +57,34 @@ def set_api_key_and_url(key: str, url: str):
         config.write(f)
 
 
-def initialize_config():
+def initialize_config(force=False):
     key, url = get_api_key_and_url()
-    if not key or not url:
+    if force or (not key or not url):
+        url = url or "https://na1.polyapi.io"
         print("Please setup your connection to PolyAPI.")
-        url = input("? Poly API Base URL (https://na1.polyapi.io): ") or "https://na1.polyapi.io"
-        key = input("? Poly App Key or User Key: ")
+        url = input(f"? Poly API Base URL ({url}): ").strip() or url
+
+        if not key:
+            key = input("? Poly App Key or User Key: ").strip()
+        else:
+            key_input = input(f"? Poly App Key or User Key ({key}): ").strip()
+            key = key_input if key_input else key
 
         if url and key:
+            errors = []
+            if not is_valid_polyapi_url(url):
+                errors.append(f"{url} is not a valid Poly API Base URL")
+            if not is_valid_uuid(key):
+                errors.append(f"{key} is not a valid Poly App Key or User Key")
+            if errors:
+                print_yellow("\n".join(errors))
+                sys.exit(1)
+
             set_api_key_and_url(key, url)
+            print_green(f"Poly setup complete.")
 
     if not key or not url:
-        print("Poly API Key and Poly API Base URL are required.")
+        print_yellow("Poly API Key and Poly API Base URL are required.")
         sys.exit(1)
 
     return key, url
diff --git a/polyapi/utils.py b/polyapi/utils.py
index 259e727..a5141a6 100644
--- a/polyapi/utils.py
+++ b/polyapi/utils.py
@@ -1,6 +1,7 @@
 import keyword
 import re
 import os
+import uuid
 from typing import Tuple, List
 from colorama import Fore, Style
 from polyapi.constants import BASIC_PYTHON_TYPES
@@ -208,4 +209,23 @@ def rewrite_reserved(s: str) -> str:
 
 
 def rewrite_arg_name(s: str):
-    return rewrite_reserved(camelCase(s))
\ No newline at end of file
+    return rewrite_reserved(camelCase(s))
+
+
+valid_subdomains = ["na[1-2]", "eu[1-2]", "dev"]
+
+
+def is_valid_polyapi_url(_url: str):
+    # Join the subdomains into a pattern
+    subdomain_pattern = "|".join(valid_subdomains)
+    pattern = rf"^https://({subdomain_pattern})\.polyapi\.io$"
+    return re.match(pattern, _url) is not None
+
+
+def is_valid_uuid(uuid_string, version=4):
+    try:
+        uuid_obj = uuid.UUID(uuid_string, version=version)
+    except ValueError:
+        return False
+
+    return str(uuid_obj) == uuid_string
diff --git a/pyproject.toml b/pyproject.toml
index 3969c19..3ae5911 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@ requires = ["setuptools>=61.2", "wheel"]
 
 [project]
 name = "polyapi-python"
-version = "0.3.0"
+version = "0.3.1.dev0"
 description = "The Python Client for PolyAPI, the IPaaS by Developers for Developers"
 authors = [{ name = "Dan Fellin", email = "dan@polyapi.io" }]
 dependencies = [