diff --git a/README.txt b/README.txt
index 5e349dc..cce264e 100644
--- a/README.txt
+++ b/README.txt
@@ -85,9 +85,45 @@ Files:
    main/api.php - Message API
 
 API usage:
+
+GET /api.php - Get messages
+   Parameters:
+   - limit: number of messages (1-100, default: 50)
+   
+   Example:
+   curl http://localhost/api.php?limit=10
+   
+   Response:
+   {
+       "messages": [
+           {
+               "username": "user",
+               "message": "text",
+               "created_at": "2024-03-21 12:34:56",
+               "signature": "[Signed]",
+               "is_encrypted": true
+           }
+       ]
+   }
+
+POST /api.php - Send message
+   Headers:
+   - Content-Type: application/json
+   
+   Body:
+   {
+       "username": "name",
+       "message": "text",
+       "signature": "pgp_signature",
+       "encrypted": true
+   }
+   
+   Example:
    curl -X POST http://localhost/api.php -H "Content-Type: application/json" -d '{
        "username": "name",
        "message": "text",
        "signature": "pgp_signature",
        "encrypted": true
-   }' 
\ No newline at end of file
+   }'
+   
+   Note: Messages can only be sent by unregistered usernames 
\ No newline at end of file