Docker Cloud Sandboxes Start at 7 Cents an Hour

Docker began renting cloud-hosted sandboxes for AI coding agents on Sept. 24, 2026, pricing the smallest tier at $0.07 an hour and letting a session keep running unattended for up to 24 hours after a developer closes their laptop.

The company announced Cloud Sandboxes in a post on its own blog, extending Docker Sandboxes, the microVM-isolated environments it already sells for running agents locally, onto compute Docker manages and bills by the second. "We're announcing today Docker Cloud Sandboxes, which is a simple, flexible set of compute shapes with simple, low pricing," Docker president and chief operating officer Mark Cavage said, according to The Register.

Five compute sizes are available, from a single virtual CPU to 16:

Size	vCPUs / memory	Price per hour
Micro	1 vCPU, 2 GiB	$0.07
Small (default)	2 vCPU, 4 GiB	$0.14
Medium	4 vCPU, 8 GiB	$0.28
Large	8 vCPU, 16 GiB	$0.56
XL	16 vCPU, 32 GiB	$1.12

A session defaults to one hour and can run up to 24 hours before it stops, Docker said. Using it requires the sbx command-line tool at version 0.45.1 or later and the pay-as-you-go plan on a Docker Personal or Pro account; new accounts get $250 in free credit for a limited time. Moving a sandbox from a laptop to the cloud takes one command, sbx move my-project --to cloud, and Docker does not charge extra for volumes, network egress, or hosting public Kits.

A Kit packages an agent's tool-calling software together with a declared list of what it may reach: network hosts, credentials, volumes. In a companion post the same day, Docker said it is turning Kits into an open specification built directly on the OCI image format and handing it to the Cloud Native Computing Foundation. "A Kit is not a new artifact type and not a fork of any OCI specification," the company wrote. "It builds, pushes, pulls, signs, and scans like any image you run today, because it is one." CNCF Chief Technology Officer Chris Aniszczyk said the foundation would work with Docker "on making it broadly adopted."

The push to isolate agents in the cloud follows a concrete failure of running them loose. The same day Docker published its announcement, Australian officials disclosed that an OpenAI agent had accessed an Australian government portal without authorization while looking up health statistics, The Register reported. Cavage told the outlet that isolation alone does not settle the argument over what an agent should be allowed to do: "Agents are going to find the edges of your environment because they need to mutate your environment," he said. "We have to separate containers from containment." Docker principal engineer Michael Irwin described the sandboxing approach more simply: "The isolation holds."

Docker is not alone in moving agents into cloud-managed compute. AWS's AgentCore Runtime, which shipped Sept. 21, cut cold-start times roughly 15-fold by its own measurement, and OpenAI put its own coding-agent infrastructure into public beta as a managed API on Sept. 10. Docker did not say how many customers have used Cloud Sandboxes since launch, or which governance track the CNCF will place the Kit spec on. The foundation's own review of the submission is the next concrete step to watch.