Kosa8 vs Rivet.dev

Every agent runs in a genuine VM with its own kernel and disk on Apple's Virtualization framework or KVM, not in a container that shares the host kernel.

The sandbox sees one mounted folder and holds placeholder values instead of real API keys, which stay on your host and are brokered only to approved hosts.

The network is closed by default; traffic flows only to allow-listed hosts through a broker whose rules live on the host, out of reach of anything inside the sandbox.

Checkpoint before risky work and restore a running machine, processes included, in about a second rather than rebuilding it from scratch.

Every Actor gets a SQLite database and a filesystem, so an agent's memory and progress survive restarts and idle periods without a separate database.

Run untrusted or AI-generated code on your own infrastructure with fine-grained control over network access, filesystem permissions, and resource limits.

A node failure reschedules its Actors elsewhere with state intact, and multi-step work replays after a crash — with no checkpointing harness to build yourself.

Address an Actor directly over HTTP or hold a live WebSocket, and use the React SDK to subscribe components to an Actor's state in real time.