Multiple git account associated to folders and SSH Confiog

I'm working with multiple GitHub account (let's say userA and userB ...). My folder architecture is

Projects/
 |- userA/
     |- projectA1/
     |- projectA2/
     |- ... All the repository accessible by userA
 |- userB/
     |- projectB1/
     |- projectB2/
     |- ... All the repository accessible by userB
 |- ...

Some users may need an SSH config, some others may not.

Is it possible to have a set up so when I'm working anywhere under the folder userA, then the git user is userA, and similarly, when working under a folder userX, the git user is userX?

With the help of @phd's comment and those other answers

• Use different .gitconfig per folder
• Use different ssh keys for git accounts

here is how I did it.

I didn't manage to do the set up with some accounts not using ssh key. So I made all of them use one. In this example I gave userA and userB.

1. Update the ~/.giconfig to use different .gitconfig files depending on the folder:

~/.gitconfig:

[includeIf "gitdir:~/userA/"]
    path = ~/userA/.gitconfig-user-a

[includeIf "gitdir:~/userB/"]
    path = ~/userB/.gitconfig-user-b

~/userA/.gitconfig-user-a:

[user]
    name = userA
    email = user.a@email.com

~/userB/.gitconfig-user-b:

[user]
    name = userB
    email = user.b@email.com

2. Follow the steps of Generating a new SSH key and adding it to the ssh-agent. One for each user:

ssh-keygen -t ed25519 -C "user.a@email.com" -f "User/valentin/.ssh/id_ed25519_user_a"
ssh-keygen -t ed25519 -C "user.b@email.com" -f "User/valentin/.ssh/id_ed25519_user_b"

3. Update your ~/.ssh/config:

Host github_user_a
  HostName github.com
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_ed25519_user_a

Host github_user_b
  HostName github.com
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_ed25519_user_b

4. Add the ssh keys to the related github accounts. You can follow Adding a new SSH key to your GitHub account.

For user_x, copy the key with

pbcopy < ~/.ssh/id_ed25519_user_x.pub

And paste it in github.com > Settings > Access > SSH and GPG keys > SSH keys > New SSH key > Key:

5. When cloning a repo (userA/repo_a in the folder userA for example), use SSH instead of https, and replace github.com with github_user_a:

git clone git@github_user_a:userA/repo_a.git