1#!/usr/bin/env python3
2"""
3Telegram Session String Generator
4 
5This script generates a session string that can be used for Telegram authentication
6with the Telegram MCP server. The session string allows for portable authentication
7without storing session files.
8 
9Usage:
10    python session_string_generator.py
11 
12Requirements:
13    - telethon
14    - python-dotenv
15 
16Note on ID Formats:
17When using the MCP server, please be aware that all `chat_id` and `user_id`
18parameters support integer IDs, string representations of IDs (e.g., "123456"),
19and usernames (e.g., "@mychannel").
20"""
21 
22import asyncio
23import io
24import os
25import sys
26 
27from dotenv import load_dotenv
28from telethon import errors
29from telethon.sessions import StringSession
30from telethon.sync import TelegramClient
31 
32load_dotenv()
33 
34 
35def _qr_login(client: TelegramClient) -> None:
36    import qrcode
37 
38    qr = client.qr_login()
39 
40    print("\n----- QR Code Login -----\n")
41 
42    qr_obj = qrcode.QRCode(border=1)
43    qr_obj.add_data(qr.url)
44    qr_obj.make(fit=True)
45    f = io.StringIO()
46    qr_obj.print_ascii(out=f, invert=True)
47    print(f.getvalue())
48 
49    print("Scan the QR code above with your Telegram app:")
50    print("  Open Telegram > Settings > Devices > Link Desktop Device\n")
51    print(f"Or open this link on a device where you're logged in:\n  {qr.url}\n")
52    print(f"Expires at: {qr.expires.strftime('%H:%M:%S')}")
53    print("Waiting for you to scan...")
54 
55    try:
56        client.loop.run_until_complete(qr.wait(timeout=120))
57    except asyncio.TimeoutError:
58        print("\nQR code expired. Please try again.")
59        client.disconnect()
60        sys.exit(1)
61    except errors.SessionPasswordNeededError:
62        pw = input("\nTwo-factor authentication enabled. Please enter your password: ")
63        client.sign_in(password=pw)
64 
65 
66def _phone_login(client: TelegramClient) -> None:
67    phone = input("Please enter your phone (or bot token): ")
68 
69    try:
70        client.send_code_request(phone)
71    except errors.FloodWaitError as e:
72        print(f"\nFlood wait error; you must wait {e.seconds} seconds before trying again.")
73        client.disconnect()
74        sys.exit(1)
75    except errors.PhoneNumberInvalidError:
76        print("\nThe phone number is invalid.")
77        client.disconnect()
78        sys.exit(1)
79    except Exception as e:
80        print(f"\nError sending code: {e}")
81        client.disconnect()
82        sys.exit(1)
83 
84    code = input("\nPlease enter the code you received: ")
85    try:
86        client.sign_in(phone, code)
87    except errors.SessionPasswordNeededError:
88        pw = input("Two-factor authentication enabled. Please enter your password: ")
89        client.sign_in(password=pw)
90 
91 
92def main() -> None:
93    API_ID = os.getenv("TELEGRAM_API_ID")
94    API_HASH = os.getenv("TELEGRAM_API_HASH")
95 
96    if not API_ID or not API_HASH:
97        print("Error: TELEGRAM_API_ID and TELEGRAM_API_HASH must be set in .env file")
98        print("Create an .env file with your credentials from https://my.telegram.org/apps")
99        sys.exit(1)
100 
101    try:
102        API_ID = int(API_ID)
103    except ValueError:
104        print("Error: TELEGRAM_API_ID must be an integer")
105        sys.exit(1)
106 
107    print("\n----- Telegram Session String Generator -----\n")
108    print("This script will generate a session string for your Telegram account.")
109    print("The generated session string can be added to your .env file.")
110    print(
111        "\nYour credentials will NOT be stored on any server and are only used for local authentication.\n"
112    )
113 
114    print("Choose login method:")
115    print("  1) QR code login (recommended -- scan from your Telegram app)")
116    print("  2) Phone number + verification code")
117    method = input("\nEnter 1 or 2 [default: 1]: ").strip() or "1"
118 
119    try:
120        client = TelegramClient(StringSession(), API_ID, API_HASH)
121        client.connect()
122 
123        if not client.is_user_authorized():
124            if method == "1":
125                _qr_login(client)
126            else:
127                _phone_login(client)
128 
129        session_string = StringSession.save(client.session)
130 
131        print("\nAuthentication successful!")
132        print("\n----- Your Session String -----")
133        print(f"\n{session_string}\n")
134        print("Add this to your .env file as:")
135        print(f"TELEGRAM_SESSION_STRING={session_string}")
136        print("\nIMPORTANT: Keep this string private and never share it with anyone!")
137 
138        choice = input(
139            "\nWould you like to automatically update your .env file with this session string? (y/N): "
140        )
141        if choice.lower() == "y":
142            try:
143                with open(".env", "r") as file:
144                    env_contents = file.readlines()
145 
146                session_string_line_found = False
147                for i, line in enumerate(env_contents):
148                    if line.startswith("TELEGRAM_SESSION_STRING="):
149                        env_contents[i] = f"TELEGRAM_SESSION_STRING={session_string}\n"
150                        session_string_line_found = True
151                        break
152 
153                if not session_string_line_found:
154                    env_contents.append(f"TELEGRAM_SESSION_STRING={session_string}\n")
155 
156                with open(".env", "w") as file:
157                    file.writelines(env_contents)
158 
159                print("\n.env file updated successfully!")
160            except Exception as e:
161                print(f"\nError updating .env file: {e}")
162                print("Please manually add the session string to your .env file.")
163 
164        client.disconnect()
165 
166    except Exception as e:
167        print(f"\nError: {e}")
168        print("Failed to generate session string. Please try again.")
169        sys.exit(1)
170 
171 
172if __name__ == "__main__":
173    main()
174