diff --git a/docs/configuration.md b/docs/configuration.md
new file mode 100644
index 00000000..a529e045
--- /dev/null
+++ b/docs/configuration.md
@@ -0,0 +1,21 @@
+# Configuration
+
+The Kalshi client can be configured using environment variables.
+
+## Supported variables
+
+- `KALSHI_API_KEY`
+- `KALSHI_API_SECRET`
+- `KALSHI_ENV` (e.g. `demo` or `prod`)
+
+## Example
+
+```python
+import os
+from kalshi_client import KalshiClient
+
+client = KalshiClient(
+    api_key=os.getenv("KALSHI_API_KEY"),
+    api_secret=os.getenv("KALSHI_API_SECRET"),
+    environment=os.getenv("KALSHI_ENV", "demo")
+)