Fair point, and you're right that those three steps alone aren't a security boundary. They're defense-in-depth, not the primary isolation.

The actual security model is the architecture itself: the sandbox runs in its own VM inside a private VPC. It has no AWS keys, no database credentials, no LLM API tokens. The only thing it can do is talk to the control plane, which validates every request and scopes every operation to that one session.

So even if you bypass all three hardening steps, you get a session token that only works inside that VPC, talking to a control plane that only lets you do things scoped to your own session. There's nothing to escalate to.

The bytecode removal, privilege drop, and env stripping are just there to make the agent's life harder if it tries to inspect its own runtime. Not the security boundary.