diff --git a/requirements.txt b/requirements.txt
index 5ff2a6a..bda4997 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,3 +6,15 @@ cryptography>=41.0.0
 
 # Optional: HTTP/2 multiplexing (faster apps_script relay)
 h2>=4.1.0
+
+# CA bundle for TLS verification — skipped on Windows (uses system cert store).
+certifi>=2024.1.0; sys_platform != "win32"
+
+# Optional: Brotli decompression (modern websites send `br` encoding)
+brotli>=1.1.0
+
+# Optional: Zstandard decompression (some CDNs now serve `zstd`)
+zstandard>=0.22.0
+
+# LAN interface detection now uses only the Python standard library
+# (works on Windows, Linux, macOS, Android/Termux without a C compiler).
\ No newline at end of file