Google makes Agent Substrate 1.0 generally available on GKE

Google released Agent Substrate 1.0 and made it generally available on Google Kubernetes Engine on November 5, giving eligible Google Cloud customers a managed deployment path for the open-source agent runtime. The project has also been accepted into the Cloud Native Computing Foundation’s Sandbox, with onboarding still in progress.

Agent Substrate separates an agent’s durable state from the compute that runs it. An Actor holds the agent’s memory, files and identity; a Worker is a sandbox that can be started in advance and reused rather than remaining permanently assigned to one Actor.

When an application suspends an idle Actor, the runtime snapshots its memory and local files to storage, then releases the Worker. A later request restores that snapshot onto an available warm Worker. In this way, idle sessions can give up compute without discarding their state.

Google says Agent Substrate can resume suspended Actors in under 500 milliseconds, reach 10 times the density of standard container runtimes and handle more than 500 suspend-and-resume activations per second. The opened evidence did not independently verify those performance figures.

Google’s GKE documentation says Agent Substrate supports gVisor and Cloud Hypervisor for sandbox isolation. Gateways can enforce inbound and outbound policy and inject credentials according to Actor identity, keeping secrets outside the agent sandbox.

The GKE deployment requires a Standard cluster running version 1.37 or later and Workload Identity Federation for GKE. Autopilot clusters are not supported. Open network connections do not survive suspension, and GPU device passthrough into Actor containers is not supported.

Google says the core project can run on Kubernetes clusters outside Google Cloud, while the GKE deployment tooling is limited to eligible Google Cloud customers. The documentation does not define eligibility or provide pricing.

The CNCF Sandbox application record shows that the Technical Oversight Committee vote passed, Google and CNCF completed a contribution agreement, and an onboarding issue was created on October 20. Google described the donation as a move toward vendor-neutral ownership. The available record, however, does not establish that every onboarding task was complete by the November 5 announcement.