BLE noob question here

[Jihosong]

Hello,

I am trying to implement a Bluetooth functionality to pass on wifi information for my IoT device to connect to the internet
(Rpi 4B+, Pi OS Bullseye, and program written in C/C++)

I started to research the Rpi Bluetooth examples written in C/C++ this week.
Surprisingly there are not many I found.

So far I know Bullseye comes with Bluez and I need to figure out how to GAP -> GATT to transfer wifi info two-way between the central and peripheral. This is how much I know about Bluetooth at the moment. First of all, please let me know if this makes sense to you.

Then, I am curious about what gattlib does with bluez?
Can you implement gatt without gattlib and just with just bluez?
Or is gattlib providing more dev-friendly and high-level interface to implement GATT than just using Bluez?

Please let me know. Thanks!