How to get the last commit ID of a remote repo using curl-like command?

try this command

git log --format="%H" -n 1

I think what you want is this:

git ls-remote $URL HEAD

If HEAD doesn't exist in the remote repository, then you likely want:

git ls-remote $URL refs/heads/master

Note that in the first instance, HEAD is going to point to the default branch to checkout in the repository. You need to be sure that's the branch you want, or just use the second form and specify the one you want (replace refs/heads/master with the name of the branch you want: refs/heads/BRANCH_NAME.

Another way, without using git log:

git rev-parse HEAD

You can use git ls-remote for this. Because I get a 'Unauthorized access for repository apiapp.git' I use as example torvalds linux-repo.

$ git ls-remote --heads git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
6d15ee492809d38bd62237b6d0f6a81d4dd12d15        refs/heads/master

The short hash of the last commit id is much more human readable (read: user friendly). For posterity, two ways to get the short hash of the last commit id:

git rev-parse --short HEAD

OR

git log -n1 --format="%h"