Bug 1682 – Support OpenSSH ssh-agent

2019-09-27 10:43

https://winscp.net/forum/viewtopic.php?t=28304

2019-09-27 10:46

Though it's more likely to get implemented, if you ask PuTTY team to implement it, rather than here.
https://www.chiark.greenend.org.uk/~sgtatham/putty/feedback.html

2020-07-30 09:49

Here is a proxy agent that allows WinSCP talking to OpenSSH agent:
https://github.com/ndbeals/winssh-pageant
Use with caution.

2020-08-20 11:13

https://winscp.net/forum/viewtopic.php?t=22252#101292

2021-12-09 10:00

https://winscp.net/forum/viewtopic.php?t=31752

2023-04-27 17:19

The version of Pageant included since WinSCP 5.20.4 can talk to OpenSSH.
So while you still cannot use WinSCP/PuTTY with OpenSSH agent, you can use Pageant instead for OpenSSH, PuTTY and WinSCP.
https://winscp.net/eng/docs/ui_pageant#openssh
https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/win-pageant-openssh-interop.html