How to write a bash builtin compatible with version 3+

[Bren Eser]

Hello,

I am in the process of writing a bash builtin which is compiled against
Bash 3. I am wondering if a builtin compiled against Bash 3 would work with
later versions of Bash.

Would I need to compile the code against the version of bash that is
currently installed on a machine? Would it be safe to assume a builtin
compiled against Bash 3 would work with Bash 5?  ( Ignoring different
machine architectures). What is the backward compatibility of Bash C
headers?

The code is not relying heavily on bash API, only the interface for
builtin's that receives the word list. Some functions including exit_shell
and finding/binding variables in shell is used with the builtin program.

Thanks for your response in advance.

Regards,

Bren Eser