This is the internal MTProxy in Telegram’s infrastructure, distributed through DNS TXT record of apv3.stel.com.
The MTProxy is in FakeTLS mode, the fronting domain is www.google.com.
I once wrote a Python script to extract the current proxy config
tg_txt_decrypt.py (12.9 KB)
The current production config is,
Domain : apv3.stel.com
Date : 2026-04-27 14:02:54 UTC
Expires : 2027-04-27 14:02:54 UTC [valid]
DC 4 phone_prefix=(all)
address : 194.221.61.2:443
secret : FakeTLS host=www.google.com key=f7f7da556b4bd989fd44c9bc7b7b2a75
tg link : tg://proxy?server=194.221.61.2&port=443&secret=eef7f7da556b4bd989fd44c9bc7b7b2a757777772e676f6f676c652e636f6d
Distribution and decryption code is at,
- tdesktop/Telegram/SourceFiles/mtproto/special_config_request.cpp at 2cfdf1b32ee4160da4d0816f6b9ff26bdf41cd81 · telegramdesktop/tdesktop · GitHub
- tdesktop/Telegram/SourceFiles/mtproto/mtproto_config.cpp at 2cfdf1b32ee4160da4d0816f6b9ff26bdf41cd81 · telegramdesktop/tdesktop · GitHub
BTW the config is quite useless in China because the fake domain www.google.com would trigger TCP RST censorship. They can do it better, like distributing fake domain as www.bing.com for China’s +86 phone prefix.