diff --git a/chatmastermind/ais/openai.py b/chatmastermind/ais/openai.py
new file mode 100644
index 0000000..67c520e
--- /dev/null
+++ b/chatmastermind/ais/openai.py
@@ -0,0 +1,43 @@
+"""
+Implements the OpenAI client classes and functions.
+"""
+import openai
+from ..message import Message
+from ..chat import Chat
+from ..ai import AI, AIResponse
+
+
+class OpenAI(AI):
+    """
+    The OpenAI AI client.
+    """
+
+    def request(self,
+                question: Message,
+                context: Chat,
+                num_answers: int = 1) -> AIResponse:
+        """
+        Make an AI request, asking the given question with the given
+        context (i. e. chat history). The nr. of requested answers
+        corresponds to the nr. of messages in the 'AIResponse'.
+        """
+        raise NotImplementedError
+
+    def models(self) -> list[str]:
+        """
+        Return all models supported by this AI.
+        """
+        raise NotImplementedError
+
+    def print_models(self) -> None:
+        """
+        Print all models supported by the current AI.
+        """
+        not_ready = []
+        for engine in sorted(openai.Engine.list()['data'], key=lambda x: x['id']):
+            if engine['ready']:
+                print(engine['id'])
+            else:
+                not_ready.append(engine['id'])
+        if len(not_ready) > 0:
+            print('\nNot ready: ' + ', '.join(not_ready))