Exactly, my understanding is also that they host agents as a service. The actual use case is mentioned in the end of the article, which makes it hard to reason about.

Anyway. General advice: treat harnesses as any other (third-party) software that you run on your server. Modern harnesses (the ones from big companies, you need to subscribe to) are black boxes. Would you run a random binary you fetched from the internet on your server? Claude code, codex etc. are exactly this.