Fly.io

license

Proprietary

service

proprietary(Fly.io managed)

source

closed

clients

CLI/REST/JS/Go SDKs (client libs only, no open runtime)

isolation

Firecracker(Firecracker itself is OSS/AWS, but the Sprites product/orchestration is proprietary)

Proprietary managed sandbox SaaS; no open source runtime published (only client SDKs). Underlying Firecracker is OSS but the product is not. The product page (now fly.io/sprites) ships only client surfaces - a CLI installer, a REST API, and JavaScript, Go, Elixir and Python SDKs - against a hosted Fly.io control plane, with metered CPU, memory and storage pricing and no self-hostable runtime or source release.

• https://sprites.dev/ recorded 2026-08-13

  Sprites = hardware-isolated Firecracker execution env for arbitrary code; managed service, CLI/REST/JS/Go clients; no self-hostable open runtime