Agent Sandboxing
Agent Sandboxing is how Agent Manager isolates a running agent's code from the underlying host. A spectrum of increasingly strict runtime tiers, chosen per environment, that only applies to Platform-Hosted agents (the platform doesn't control the runtime of an Externally-Hosted agent).
Three Tiers​
| Tier | Isolation mechanism | Trade-off |
|---|---|---|
| runc (default) | Standard container runtime; shares the host kernel | No special hardware needed; every agent gets this by default (hardened security context, network policy, warm pool) |
| gVisor | A userspace kernel (runsc) intercepts syscalls before they reach the host kernel | Stronger isolation than runc, no special hardware, but adds syscall interception overhead |
| Kata Containers | Each agent boots in its own lightweight VM with a separate guest kernel | Strongest isolation — no shared kernel at all — but requires nested virtualization (/dev/kvm) on the node |
Isolation Tier Is an Environment-Level Setting​
You don't choose a tier per agent — you choose it once when creating an environment, and every agent deployed or promoted into that environment runs under that tier. Adding a stronger-tier node to your cluster doesn't affect existing runc environments; only new environments (or environments explicitly configured for that tier) schedule pods onto it.
Under the hood, the tier is implemented as a Kubernetes RuntimeClass: deploying or promoting an agent into a gVisor or Kata environment sets runtimeClassName on its pod spec, and that RuntimeClass's own scheduling rules place the pod on a node dedicated to that tier.
Agents run sandboxed under the standard runc runtime by default. Agent Manager also supports stronger per-environment isolation tiers — gVisor (userspace kernel) and Kata Containers (per-agent VM) — but they have hardware/OS requirements and need a dedicated node. For more information, see the gVisor and Kata Containers setup guides.
For the setup steps and hardware requirements for each tier, see gVisor and Kata Containers in Guides.