Modal launches VM Sandboxes, giving agents full Linux VMs with Docker support

Modal has made VM Sandboxes generally available, giving agents a full Linux VM through the same APIs, modal.Images, sub-second cold starts and CPU/memory bursting as its existing gVisor-based Sandboxes. Users enable it with runtime="vm" when they need Docker, FUSE filesystems or niche Linux kernel features, while gVisor remains the default runtime. Modal says early customers have already launched over 20 million VMs, with Linear running every Coding Session on a VM Sandbox and Legora and Snorkel using them for legal agent evals and agent simulations.