diff --git a/interpolation.py b/interpolation.py
new file mode 100644
index 0000000..f9a8fe2
--- /dev/null
+++ b/interpolation.py
@@ -0,0 +1,6 @@
+def interpolate_env_vars(config):
+    import os
+    for key, value in config.items():
+        if isinstance(value, str):
+            config[key] = value.replace('${', 'os.getenv(')
+    return config
\ No newline at end of file