gVisor vs semantic
gVisor is an Apache-2.0 application kernel written in Go. Its runsc runtime intercepts system calls and plugs into Docker and Kubernetes as an OCI runtime. [1][2]
gVisor isolates; it does not decide what the agent may do. It has no egress allowlist, credential broker or file, Git and SSH policy. [1][3] Semantic gives each agent a microVM and enforces that policy on the host.
| gVisoropen source runtime | Semantic (smx)microVM + policy on your machines | |
|---|---|---|
| Isolation | User-space application kernel (Sentry, Gofer) [1] | One microVM per agent, own kernel |
| Where it runs | Self-hosted via Docker or Kubernetes [1] | Managed private beta; on-prem for enterprise (contact us) |
| Egress rules | not documented (netstack, host or none modes; rate limiting) [3] | Security profiles enforced by host firewall; metadata and link-local always closed |
| Credentials kept out | not documented | Git tokens, SSH keys and model sign-ins stay on the host |
| File, Git, SSH permissions | not documented | Per path, repo, branch and SSH host; deny beats allow; enforced on the host |
| Tamper-evident agent log | not documented | Hash-chained log of runs, events and refusals; read with smx agent logs |
| Snapshots, pause/resume | runsc checkpoint and restore [4] | Snapshot, pause and resume with memory, disk and running processes |
| Local hosts (Linux / WSL2 / macOS) | Linux 5.6+ only [5] | Linux (KVM) and Windows via WSL2; macOS planned |
| License | Apache-2.0 [2] | Proprietary (private beta) |
Which one fits
When gVisor fits better
- You want container-like startup and resource use with a stronger boundary than a shared kernel. [1]
- You want a drop-in OCI runtime for existing Docker or Kubernetes. [1]
When Semantic fits better
- You want hardware virtualization: one microVM and kernel per agent.
- Agents work on your repos and you need branch-level Git and per-path file permissions enforced outside the agent.
- You need a tamper-evident log of what the agent did inside the sandbox, including refusals.
Checkpoint and restore
gVisor can checkpoint a container and restore it, loading memory in the background and skipping zero pages; open TCP connections are lost in host network mode. [4] Semantic snapshots, pauses and resumes sandboxes with memory, disk and running processes.
Questions
Is gVisor a VM?
No. It is an application kernel that intercepts system calls without hardware virtualization. [1]
Does gVisor run on macOS?
No, it needs Linux 5.6 or newer. [5]
Sources
- gVisor docs · last verified 2026-10-27
- gVisor repository · last verified 2026-10-27
- gVisor networking · last verified 2026-10-27
- gVisor checkpoint and restore · last verified 2026-10-27
- gVisor install · last verified 2026-10-27