Sprites by Fly.io is a stateful sandbox environment platform designed to run arbitrary code in isolated Linux computers. Each Sprite is a hardware-isolated execution environment that can persist across runs, making it useful for AI agents, uploaded binaries, developer tools, and application workloads. The platform is built around checkpoint and restore, allowing workloads to pause, resume, and keep state instead of rebuilding the environment repeatedly. Sprites provide a fast NVMe filesystem that syncs continuously to durable external object storage. This tiered storage approach gives users compatibility with normal Linux filesystem behavior while only charging for the data they actually use. Developers can start with the Sprites CLI by logging in, creating a Sprite, executing commands, and connecting to the console. The platform also supports REST API access and SDKs for JavaScript, Go, Elixir, and Python. Pricing is usage-based across CPU time, memory time, hot storage, and cold storage. By combining sandbox VMs, persistent filesystems, checkpointing, APIs, network policy, and pay-as-you-go pricing, Sprites gives developers a practical runtime for AI agents and untrusted code execution.