A Runtime sandbox is infrastructure in this sense. It is a Linux machine with
its own kernel, sudo and a network that you control. You rent it by the
second, and CPU is billed by measured use: $0.025 per active vCPU-hour and
$0.0075 per GiB-hour of memory. There is no plan fee. Every new account
gets 100 free hours of a 1 GB machine in the first 30 days, with no card required
(pricing).
The NIST definition
NIST's definition of cloud computing is SP 800-145, from September 2011. It names three service models. In IaaS, "the consumer is able to deploy and run arbitrary software, which can include operating systems and applications". The consumer "does not manage or control the underlying cloud infrastructure". The same document lists five essential characteristics of any cloud:
| Characteristic | In NIST's words, shortened | On Runtime |
|---|---|---|
| On-demand self-service | Provision "without requiring human interaction" | One API call, CLI command or MCP tool |
| Broad network access | "Available over the network" | HTTPS API, SDKs, CLI and a remote MCP server |
| Resource pooling | Resources "dynamically assigned and reassigned" | Shared CPU with a guaranteed floor |
| Rapid elasticity | Scale "outward and inward commensurate with demand" | 100 concurrent sandboxes; paused ones free up CPU and memory |
| Measured service | Usage "monitored, controlled, and reported" | Per-run usage, CSV export and a daily cost |
IaaS, PaaS and SaaS
| Model | You manage | Example |
|---|---|---|
| IaaS | The operating system and everything above | Virtual machines, sandboxes, disks |
| PaaS | Your application and data | A platform that runs your web app for you |
| SaaS | Nothing but your settings | Email, a CRM |
Agent sandboxes are IaaS by design. An agent needs to install packages, run a shell and open ports. A platform that hides the machine does not allow these actions.
Related
- What is a bare-metal server?
- What is serverless computing?
- What is an agent sandbox?
- What is per-second billing?
Sources
Checked 25 October 2026.