I found ZeroClaw plus Hetzner to be a good option. I've been using it for a week, and it's stable and robust.

Complex abilities unlocked calling a FastAPI server with one skill for each endpoint

FastAPI server on the same Hetzner box? The endpoints are written by ZeroClaw?

I use another vps for FastAPI. I assume the vps with Zeroclaw will become compromised.

I don't use other people's skills. Just use Claude Code for adding endpoints and the relative skill.

Communication via Telegram bot, calendar via synced CalDAV server. Emails not connected; I don't need it personally.

LLM API is OpenCode Go Minimax. $10/month capped, I have never hit the limits.