diff --git a/GUIDE_API_KEY.md b/GUIDE_API_KEY.md
index 688b6c1..4af8308 100644
--- a/GUIDE_API_KEY.md
+++ b/GUIDE_API_KEY.md
@@ -21,17 +21,9 @@ This guide explains how to create and configure API keys for use with the Google
   - API restrictions: select **Google Sheets API** only.
 - Do not leave keys unrestricted in production.
 
-## Example `config.json` snippet
+## Configure the project
 
-To configure one key:
-
-```json
-{
-  "apiKeys": [
-    "YOUR_API_KEY_1"
-  ]
-}
-```
+In `config.json`, add the keys under the `apiKeys` array. Here's an example using apiKeys:
 
 To configure multiple keys with per-key rate limits:
 
diff --git a/readme.md b/readme.md
index e186540..984cde8 100644
--- a/readme.md
+++ b/readme.md
@@ -36,20 +36,24 @@ Here is an example `config.json` matching the repository's `config.example.json`
     { "key": "YOUR_API_KEY_2", "rateLimitPerMinute": 50 }
   ],
   "serviceAccounts": [
-    { "path": "credentials.json", "rateLimitPerMinute": 50 }
+    { "path": "credentials.json", "rateLimitPerMinute": 50 },
+    { "path": "credentials_2.json", "rateLimitPerMinute": 50 }
   ],
   "documents": [
     {
       "documentId": "YOUR_SPREADSHEET_ID",
       "outputDir": "output/your-document",
       "sheets": [
-        { "name": "Sheet1", "outputFilename": "sheet1.csv" }
+        { "name": "Sheet1", "outputFilename": "sheet1.csv" },
+        { "name": "Sheet2", "outputFilename": "sheet2.csv" }
       ]
     }
   ]
 }
 ```
 
+Your `config.json` should ONLY contain `apiKeys` OR `serviceAccounts`.
+
 ## Rate limiting
 
 The app enforces a maximum of `rateLimitPerMinute` requests per minute to avoid exceeding API limits.