# Design

# The ideas behind it

Destructive and reproducible. Uploads remove the destination and copy from scratch, every time; venvs are recreated, not reused. After each deploy, the server has exactly what your script says it should have — no leftovers from previous versions. (The one safety net: paths like /, /home or /etc are rejected before anything is removed.) See Reproducibility for how far that guarantee reaches.

Fail early, fail clearly. Models validate on construction: a relative path or a service name that would corrupt the INI file blows up on your laptop with a useful message, before touching the server. Functions that need sudo check for it upfront — an immediate error with instructions, instead of the classic hang waiting for a password that will never come.

Trust the user. The library validates form (types, absolute paths, dangerous characters), not your facts: if you hand-build a PythonInstance pointing at an exotic interpreter, it's accepted. You know what's on your server.

# What it is not

• Not Ansible/Terraform. No inventories, no state, no declarative idempotency. Imperative on purpose.
• Not provisioning. It installs supervisor because services are its job, and that's where it stops: nginx, databases and the rest of your server are up to you.
• No secret management. The passwords you pass in are your environment's responsibility.
• No fleet orchestration. One connection, one server. For several, write a loop.
• Linux targets only. The machine you deploy from can be Windows, macOS or Linux.