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I've been running coding agents in VMs, and the worst part was always credentials. Either I pasted a token into the VM and hoped, or I did everything myself. So I built foca. It's basically ssh-agent for secrets: the VM asks, I tap Touch ID, it gets the token. github.com/bpinto/foca

Bruno Pinto

@bpinto.com

When something in the VM wants a secret, I get a Touch ID prompt on my Mac saying which secret, which VM and which program. On Linux it's the normal polkit password dialog. If I say no, it gets nothing.

Bruno Pinto

@bpinto.com

The prompt tells you who's asking. If the kernel can confirm the process, it shows it plainly. If it only has the VM's word for it, it says so: "gh via claude (unverified)". A caller can't sneak its own text into the prompt either.

Bruno Pinto

@bpinto.com

Each VM or container gets its own socket and its own vault. If a secret isn't exposed to that VM, asking for it looks exactly like asking for one that doesn't exist.

Bruno Pinto

@bpinto.com

My favourite bit: actions. Some things shouldn't be a token sitting in the VM, like AWS creds. So the host runs granted for it, with a fixed command and a checked profile name, and the VM only gets the short-lived output. credential_process = foca exec aws-creds --param profile=dev-admin

12/10/26, 3:19 pm0 reposts0 likes

Bruno Pinto

@bpinto.com

Other things it does: - approvals can last a while if you want, up to 8h - locking the screen or closing the lid drops every grant - every request goes into an audit log, denied ones included (never the values) - if it can't prompt or write the log, it says no