diff --git a/README.md b/README.md
index 5c7a8f2..3ab78ca 100644
--- a/README.md
+++ b/README.md
@@ -466,22 +466,10 @@ import pyalex
 pyalex.config.api_key = "<MY_KEY>"
 ```
 
-To check out whether your API key is indeed working, you can use the following code:
-
-```python
-import requests
-pyalex.config.retry_http_codes = None
-try:
-    pyalex.Works().filter(from_updated_date="2023-01-12").get()
-except requests.exceptions.HTTPError as e:
-    if e.response.status_code == 403:
-        logging.info("API key is NOT working 🔴")
-    else:
-        logging.error(f"Unexpected HTTP error: {e}")
-        raise
-else:
-    logging.info("API key is working 👍")
-```
+pyalex will automatically check whether your API key is valid and throw a `ValueError` if it isn't.
+
+If you want to manually check whether the API key is valid, call `pyalex._check_api_key()`
+which will return True if it is valid and False if it isn't.
 
 ## Alternatives
 
diff --git a/pyalex/__init__.py b/pyalex/__init__.py
index dfe7262..277126d 100644
--- a/pyalex/__init__.py
+++ b/pyalex/__init__.py
@@ -30,6 +30,7 @@
 from pyalex.api import Topics
 from pyalex.api import Work
 from pyalex.api import Works
+from pyalex.api import _check_api_key
 from pyalex.api import autocomplete
 from pyalex.api import config
 from pyalex.api import invert_abstract
@@ -63,4 +64,5 @@
     "config",
     "invert_abstract",
     "OpenAlexResponseList",
+    "_check_api_key",
 ]
diff --git a/pyalex/api.py b/pyalex/api.py
index 007a1db..7c6e04e 100644
--- a/pyalex/api.py
+++ b/pyalex/api.py
@@ -1,5 +1,8 @@
+import datetime
 import logging
 import warnings
+from dataclasses import dataclass
+from dataclasses import field
 from urllib.parse import quote_plus
 from urllib.parse import urlunparse
 
@@ -13,7 +16,12 @@
     __version__ = "0.0.0"
 
 
-class AlexConfig(dict):
+def _check_api_key():
+    raise NotImplementedError()
+
+
+@dataclass
+class AlexConfig:
     """Configuration class for OpenAlex API.
 
     Attributes
@@ -34,22 +42,21 @@ class AlexConfig(dict):
         List of HTTP status codes to retry on.
     """
 
-    def __getattr__(self, key):
-        return super().__getitem__(key)
+    email: str | None = None
+    user_agent: str = f"pyalex/{__version__}"
+    openalex_url: str = "https://api.openalex.org"
+    max_retries: int = 0
+    retry_backoff_factor: float = 0.1
+    retry_http_codes: list[int] = field(default_factory=lambda: [429, 500, 503])
+    api_key: str | None = None
 
-    def __setattr__(self, key, value):
-        return super().__setitem__(key, value)
+    def __setattr__(self, prop, val):
+        super().__setattr__(prop, val)
+        if prop == "api_key" and val and not _check_api_key():
+            raise ValueError("Invalid API key. Please check your OpenAlex API key.")
 
 
-config = AlexConfig(
-    email=None,
-    api_key=None,
-    user_agent=f"pyalex/{__version__}",
-    openalex_url="https://api.openalex.org",
-    max_retries=0,
-    retry_backoff_factor=0.1,
-    retry_http_codes=[429, 500, 503],
-)
+config = AlexConfig()
 
 
 class or_(dict):
@@ -1094,3 +1101,24 @@ def autocomplete(s):
 # aliases
 People = Authors
 Journals = Sources
+
+
+def _check_api_key():
+    """Check if the API key is valid."""
+    bk_cods = config.retry_http_codes
+    config.retry_http_codes = None
+    dt = f"{datetime.datetime.now().year}-01-01"
+    res = None
+    try:
+        Works().filter(from_updated_date=dt).get()
+    except requests.exceptions.HTTPError as e:
+        if e.response.status_code == 403:
+            res = False
+        else:
+            logging.error(f"Unexpected HTTP error: {e}")
+            raise
+    else:
+        res = True
+    finally:
+        config.retry_http_codes = bk_cods
+        return res