From 294ecf571fd15221a25225e341d819e6184f3416 Mon Sep 17 00:00:00 2001
From: tiennm99 <tiennm99@outlook.com>
Date: Mon, 11 May 2026 21:45:51 +0700
Subject: [PATCH] docs(readme): add output format, CSV columns, rate-limit and
 visibility notes

---
 README.md | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index a82e382..6a60165 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # export-telegram-group-members
 
-Export Telegram group members
+Export Telegram group members to CSV using Telethon — admin auth required for full member visibility.
 
 ## How to use
 
@@ -23,3 +23,25 @@ pip install -r requirements.txt
 ```bash
 python main.py
 ```
+
+## Output format
+
+Results are saved to a timestamped folder (e.g. `2025-01-15 10-30-00/`). Each group produces one CSV file named after the group title:
+
+```
+id,username,first_name,last_name
+123456789,johndoe,John,Doe
+987654321,,Jane,Smith
+```
+
+Columns: `id`, `username`, `first_name`, `last_name`. Members without a username have an empty `username` field.
+
+## Rate limits and visibility notes
+
+- Telegram limits how fast you can fetch participants; large groups may take longer.
+- For **supergroups**, only admins can retrieve the full member list — regular members see a partial list or get an error.
+- For private groups where you are not a member, access will be denied.
+
+## License
+
+Apache-2.0 — see [LICENSE](LICENSE).