Field note
Cursor's 19 August changelog gives cloud agents three things that change their shape: subscriptions, custom modes, and subagents on their own machines. An agent can now subscribe to an event source — a pull request, a Slack thread, or a schedule — and wake when something happens there, rather than being invoked. Cloud agents automatically subscribe to the pull requests they open and drive them to completion, fixing CI and answering bot comments.
The mechanism is a standing goal attached to an event stream. In Slack the documented instruction is to ask the agent to check back in an hour and keep going until feedback has landed, which means the agent holds intent across gaps in which nothing is asked of it. Custom modes pin a skill so it stays active for a session, and subagents each get an isolated copy of the project with clean context in their own cloud environment, so parallel fixes do not collide.
Once the trigger is an event rather than a prompt, the reviewable artifact is the subscription, not the conversation. That is the direction described in agent work moving into harnesses, factories and accepted artifacts, and it follows the execution boundary Cursor drew when it moved agent work into customer-managed machines. The agent harness hub tracks both halves.
The changelog states capability and notes subscriptions are cloud-agent only for now; it publishes no completion or intervention rates. The condition to watch is whether a subscription exposes an auditable record of what woke the agent and what it changed, because an always-on agent without that record is indistinguishable from an unattended one.