diff --git a/README.md b/README.md
index e450cc1..e295bbe 100644
--- a/README.md
+++ b/README.md
@@ -311,3 +311,16 @@ This directory contains classes related to managing products. It includes `Produ
 #### reasoning_engines ####
 
 This directory contains logic and interfaces for reasoning engines, including `GPTModels.py`.
+
+## Environment Variables ##
+
+The application expects several API keys to be available through environment
+variables:
+
+- `SERP_API_KEY`
+- `BROWSERLESS_API_KEY`
+- `OPENROUTER_API_KEY`
+
+Copy `example.env` and populate these values, then place the resulting file in a
+`vars/` directory at the project root. Keep the `vars/` directory unversioned so
+your credentials remain private.
diff --git a/example.env b/example.env
index 906ba98..8af12b8 100644
--- a/example.env
+++ b/example.env
@@ -1,8 +1,7 @@
-OPEN_API_KEY = "xxx"
 SERP_API_KEY = "xxx"
 BROWSERLESS_API_KEY = "xxx"
 OPENROUTER_API_KEY = "xxx"
 
 Example file for illustrative purposes, populate with real values and place into a vars/ directory at root of project.
 
-Keep the vars/ directory unversioned and in gitignore!
\ No newline at end of file
+Keep the vars/ directory unversioned and in gitignore!