# OpenSandbox Sandbox Protocol
The Sandbox Protocol is [[OpenSandbox]]'s OpenAPI-defined contract covering sandbox lifecycle, diagnostics, execution, and egress. It is the abstraction that makes the platform pluggable: any third party can implement a custom runtime backend (beyond the built-in Docker and Kubernetes ones) as long as it speaks the protocol. Without it, OpenSandbox would just be a wrapper around one runtime.
## Related
- [[OpenSandbox]]
- [[execd daemon]]
- [[Docker Sandboxes]]
- [[AI Agents]]