Agent projects expose limits of sandboxing for agent fleets

CNCF Ambassador Lin Sun of Solo.io wrote on July 7, 2026 that sandboxing alone is insufficient for running large-scale AI agent fleets, contrasting the Kubernetes SIG Apps project agent-sandbox with the newer agent-substrate project. Agent-substrate dynamically wakes agents on invocation using lightweight sandboxes like gVisor or Kata Containers, enabling shared worker pools instead of always-on pods. Sun's team is exploring integration with kagent and agentgateway, highlighting that secure isolation and fleet-level operational efficiency are separate problems that both need solving.

CNCF Ambassador Lin Sun of Solo.io wrote on July 7, 2026 that sandboxing alone is not enough to run large-scale AI agent fleets, contrasting the Kubernetes SIG Apps project agent-sandbox with a newer, still-standalone project called agent-substrate . Agent-sandbox provides identity, persistent storage, and lifecycle management for sandboxed agent pods; agent-substrate goes further by dynamically waking agents on invocation using lightweight sandboxes such as gVisor or Kata Containers, letting many agents share one worker pool instead of running as always-on pods. Sun's team is exploring integrating agent-substrate with kagent and agentgateway . For practitioners, the takeaway is that secure isolation and fleet-level operational efficiency are separate problems, and both need solving to run agents at scale.