Add more ssh key to git repository?

[whtank]

I have two agents can fulfill requirement of my plan, but the referenced repository of this plan used ssh as authentication. Currently only one ssh can be added or set to this repository that result in only one agent can execute this plan. I hope repository can add more ssh key then plan can execute on multiple agents. 

[Przemek Bruski]

Change authentication type to none and provide keys on each of the agents. You can have as many keys as you want.

[whtank]

Two agents represents two PCs. We don't hope share the ssh key between two agents. Because it's not recommended to share a private key from a PC to any other PCs

[Mike Friedrich]

Can you explain why you need two ssh keys for authentication and why two agents cannot use the same key?