diff --git a/python-uv/README.md b/python-uv/README.md
index a4f7d38d9a..e674ad5ff3 100644
--- a/python-uv/README.md
+++ b/python-uv/README.md
@@ -1,3 +1,10 @@
 # Managing Python Projects With `uv`: An All-in-One Solution
 
 This folder provides the code examples for the Real Python tutorial [Managing Python Projects With `uv`: An All-in-One Solution](https://realpython.com/python-uv/).
+
+The sample app uses the [Cat API](https://thecatapi.com/), which requires an API key. Get one from the Cat API website and store it in an environment variable called `CAT_API_KEY` before running the app:
+
+```sh
+$ export CAT_API_KEY=<your-api-key>
+$ uv run main.py Persian
+```
diff --git a/python-uv/main.py b/python-uv/main.py
index 542fe1750b..edfe93abd6 100644
--- a/python-uv/main.py
+++ b/python-uv/main.py
@@ -1,11 +1,15 @@
 import argparse
+import os
 import sys
 
 import requests
 
 
 def get_breeds_info():
-    response = requests.get("https://api.thecatapi.com/v1/breeds")
+    response = requests.get(
+        "https://api.thecatapi.com/v1/breeds",
+        headers={"x-api-key": os.environ.get("CAT_API_KEY", "")},
+    )
     response.raise_for_status()
     return response.json()