diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4030c91b..6044ef4b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 6.2.1 - 2025-06-21
+
+- feat: make `posthog_client` an optional argument in PostHog AI providers wrappers (`posthog.ai.*`), intuitively using the default client as the default
+
 # 6.1.1 - 2025-07-16
 
 - fix: correctly capture exceptions processed by Django from views or middleware
diff --git a/posthog/__init__.py b/posthog/__init__.py
index c15aea37..0c81a4e0 100644
--- a/posthog/__init__.py
+++ b/posthog/__init__.py
@@ -676,7 +676,7 @@ def shutdown():
     _proxy("join")
 
 
-def setup():
+def setup() -> Client:
     global default_client
     if not default_client:
         if not api_key:
@@ -706,6 +706,8 @@ def setup():
     default_client.disabled = disabled
     default_client.debug = debug
 
+    return default_client
+
 
 def _proxy(method, *args, **kwargs):
     """Create an analytics client if one doesn't exist and send to it."""
diff --git a/posthog/ai/anthropic/anthropic.py b/posthog/ai/anthropic/anthropic.py
index d80e1b70..6f2461ae 100644
--- a/posthog/ai/anthropic/anthropic.py
+++ b/posthog/ai/anthropic/anthropic.py
@@ -8,7 +8,7 @@
 
 import time
 import uuid
-from typing import Any, Dict, Optional
+from typing import Any, Dict, Optional, cast
 
 from posthog.ai.utils import (
     call_llm_and_track_usage,
@@ -17,6 +17,7 @@
     with_privacy_mode,
 )
 from posthog.client import Client as PostHogClient
+from posthog import setup
 
 
 class Anthropic(anthropic.Anthropic):
@@ -26,14 +27,14 @@ class Anthropic(anthropic.Anthropic):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         """
         Args:
             posthog_client: PostHog client for tracking usage
             **kwargs: Additional arguments passed to the Anthropic client
         """
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
         self.messages = WrappedMessages(self)
 
 
diff --git a/posthog/ai/anthropic/anthropic_async.py b/posthog/ai/anthropic/anthropic_async.py
index e8c123c7..68f0c7c3 100644
--- a/posthog/ai/anthropic/anthropic_async.py
+++ b/posthog/ai/anthropic/anthropic_async.py
@@ -10,6 +10,7 @@
 import uuid
 from typing import Any, Dict, Optional
 
+from posthog import setup
 from posthog.ai.utils import (
     call_llm_and_track_usage_async,
     get_model_params,
@@ -26,14 +27,14 @@ class AsyncAnthropic(anthropic.AsyncAnthropic):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         """
         Args:
             posthog_client: PostHog client for tracking usage
             **kwargs: Additional arguments passed to the Anthropic client
         """
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
         self.messages = AsyncWrappedMessages(self)
 
 
diff --git a/posthog/ai/anthropic/anthropic_providers.py b/posthog/ai/anthropic/anthropic_providers.py
index 44509820..97bc7656 100644
--- a/posthog/ai/anthropic/anthropic_providers.py
+++ b/posthog/ai/anthropic/anthropic_providers.py
@@ -5,9 +5,12 @@
         "Please install the Anthropic SDK to use this feature: 'pip install anthropic'"
     )
 
+from typing import Optional
+
 from posthog.ai.anthropic.anthropic import WrappedMessages
 from posthog.ai.anthropic.anthropic_async import AsyncWrappedMessages
 from posthog.client import Client as PostHogClient
+from posthog import setup
 
 
 class AnthropicBedrock(anthropic.AnthropicBedrock):
@@ -17,9 +20,9 @@ class AnthropicBedrock(anthropic.AnthropicBedrock):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
         self.messages = WrappedMessages(self)
 
 
@@ -30,9 +33,9 @@ class AsyncAnthropicBedrock(anthropic.AsyncAnthropicBedrock):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
         self.messages = AsyncWrappedMessages(self)
 
 
@@ -43,9 +46,9 @@ class AnthropicVertex(anthropic.AnthropicVertex):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
         self.messages = WrappedMessages(self)
 
 
@@ -56,7 +59,7 @@ class AsyncAnthropicVertex(anthropic.AsyncAnthropicVertex):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
         self.messages = AsyncWrappedMessages(self)
diff --git a/posthog/ai/gemini/gemini.py b/posthog/ai/gemini/gemini.py
index 52e80ff5..74ba20db 100644
--- a/posthog/ai/gemini/gemini.py
+++ b/posthog/ai/gemini/gemini.py
@@ -10,6 +10,7 @@
         "Please install the Google Gemini SDK to use this feature: 'pip install google-genai'"
     )
 
+from posthog import setup
 from posthog.ai.utils import (
     call_llm_and_track_usage,
     get_model_params,
@@ -36,6 +37,8 @@ class Client:
         )
     """
 
+    _ph_client: PostHogClient
+
     def __init__(
         self,
         api_key: Optional[str] = None,
@@ -56,12 +59,14 @@ def __init__(
             posthog_groups: Default groups for all calls (can be overridden per call)
             **kwargs: Additional arguments (for future compatibility)
         """
-        if posthog_client is None:
+        self._ph_client = posthog_client or setup()
+
+        if self._ph_client is None:
             raise ValueError("posthog_client is required for PostHog tracking")
 
         self.models = Models(
             api_key=api_key,
-            posthog_client=posthog_client,
+            posthog_client=self._ph_client,
             posthog_distinct_id=posthog_distinct_id,
             posthog_properties=posthog_properties,
             posthog_privacy_mode=posthog_privacy_mode,
@@ -97,10 +102,10 @@ def __init__(
             posthog_groups: Default groups for all calls
             **kwargs: Additional arguments (for future compatibility)
         """
-        if posthog_client is None:
-            raise ValueError("posthog_client is required for PostHog tracking")
+        self._ph_client = posthog_client or setup()
 
-        self._ph_client = posthog_client
+        if self._ph_client is None:
+            raise ValueError("posthog_client is required for PostHog tracking")
 
         # Store default PostHog settings
         self._default_distinct_id = posthog_distinct_id
diff --git a/posthog/ai/openai/openai.py b/posthog/ai/openai/openai.py
index d86fecfc..3730050f 100644
--- a/posthog/ai/openai/openai.py
+++ b/posthog/ai/openai/openai.py
@@ -15,6 +15,7 @@
     with_privacy_mode,
 )
 from posthog.client import Client as PostHogClient
+from posthog import setup
 
 
 class OpenAI(openai.OpenAI):
@@ -24,16 +25,15 @@ class OpenAI(openai.OpenAI):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         """
         Args:
             api_key: OpenAI API key.
-            posthog_client: If provided, events will be captured via this client instead
-                            of the global posthog.
+            posthog_client: If provided, events will be captured via this client instead of the global `posthog`.
             **openai_config: Any additional keyword args to set on openai (e.g. organization="xxx").
         """
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
 
         # Store original objects after parent initialization (only if they exist)
         self._original_chat = getattr(self, "chat", None)
diff --git a/posthog/ai/openai/openai_async.py b/posthog/ai/openai/openai_async.py
index 76c32a74..25f9b5ab 100644
--- a/posthog/ai/openai/openai_async.py
+++ b/posthog/ai/openai/openai_async.py
@@ -1,6 +1,6 @@
 import time
 import uuid
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, cast
 
 try:
     import openai
@@ -9,6 +9,7 @@
         "Please install the OpenAI SDK to use this feature: 'pip install openai'"
     )
 
+from posthog import setup
 from posthog.ai.utils import (
     call_llm_and_track_usage_async,
     get_model_params,
@@ -24,7 +25,7 @@ class AsyncOpenAI(openai.AsyncOpenAI):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         """
         Args:
             api_key: OpenAI API key.
@@ -33,7 +34,7 @@ def __init__(self, posthog_client: PostHogClient, **kwargs):
             **openai_config: Any additional keyword args to set on openai (e.g. organization="xxx").
         """
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
 
         # Store original objects after parent initialization (only if they exist)
         self._original_chat = getattr(self, "chat", None)
diff --git a/posthog/ai/openai/openai_providers.py b/posthog/ai/openai/openai_providers.py
index 428022e8..9d1d1a6d 100644
--- a/posthog/ai/openai/openai_providers.py
+++ b/posthog/ai/openai/openai_providers.py
@@ -15,7 +15,10 @@
 from posthog.ai.openai.openai_async import WrappedChat as AsyncWrappedChat
 from posthog.ai.openai.openai_async import WrappedEmbeddings as AsyncWrappedEmbeddings
 from posthog.ai.openai.openai_async import WrappedResponses as AsyncWrappedResponses
+from typing import Optional
+
 from posthog.client import Client as PostHogClient
+from posthog import setup
 
 
 class AzureOpenAI(openai.AzureOpenAI):
@@ -25,7 +28,7 @@ class AzureOpenAI(openai.AzureOpenAI):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         """
         Args:
             api_key: Azure OpenAI API key.
@@ -34,7 +37,7 @@ def __init__(self, posthog_client: PostHogClient, **kwargs):
             **openai_config: Any additional keyword args to set on Azure OpenAI (e.g. azure_endpoint="xxx").
         """
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
 
         # Store original objects after parent initialization (only if they exist)
         self._original_chat = getattr(self, "chat", None)
@@ -63,7 +66,7 @@ class AsyncAzureOpenAI(openai.AsyncAzureOpenAI):
 
     _ph_client: PostHogClient
 
-    def __init__(self, posthog_client: PostHogClient, **kwargs):
+    def __init__(self, posthog_client: Optional[PostHogClient] = None, **kwargs):
         """
         Args:
             api_key: Azure OpenAI API key.
@@ -72,7 +75,7 @@ def __init__(self, posthog_client: PostHogClient, **kwargs):
             **openai_config: Any additional keyword args to set on Azure OpenAI (e.g. azure_endpoint="xxx").
         """
         super().__init__(**kwargs)
-        self._ph_client = posthog_client
+        self._ph_client = posthog_client or setup()
 
         # Store original objects after parent initialization (only if they exist)
         self._original_chat = getattr(self, "chat", None)
diff --git a/posthog/version.py b/posthog/version.py
index db8806db..3bad59a9 100644
--- a/posthog/version.py
+++ b/posthog/version.py
@@ -1,4 +1,4 @@
-VERSION = "6.1.1"
+VERSION = "6.2.1"
 
 if __name__ == "__main__":
     print(VERSION, end="")  # noqa: T201