An agent checks listings, feeds, prices, or repos and pings you when something changes.
“Monitor apartment listings under my filters. Ping me within the hour, good ones go fast.”
Cast agents wake on programmatic triggers: cron schedules, new mail, inbound messages. The model is only called to judge what turned up. A monitor runs exactly when its trigger fires and costs nothing in between. You create a watch by asking for it, and revoke it the same way.
An agent reads your inbox and hands you the few that matter, with drafts for the rest.
“Read my inbox at 7. Flag what needs me, draft the routine replies.”
Cast fetches the mail on the host. The agent only holds the messages: it never sees the login and never touches the mailbox.
An agent keeps notes across every conversation and answers from them later.
“Keep track of the people and plans I mention. When I ask where we left off, tell me.”
Cast agents can rewrite their memory but not their instructions. Memory grows with every conversation. The instructions stay exactly what you wrote.
An agent runs errands: booking, replying, sending. Anything that reaches other people waits for your approval.
“Schedule my meetings. Find times that work, book only after I confirm.”
Cast agents act only through the tools you granted. Cast runs those tools on the host and keeps the credentials there. Anything with consequences, like sending or booking, asks you first.
The agent lives in a container, and everything in or out crosses Cast. Most stacks sandbox an agent’s risky tools. Cast sandboxes the agent itself.
Allowed and possible are the same list.
One agent works with several people, each in their own private thread.
“Plan the Portugal trip with the three of us. Keep our research separate and the itinerary shared.”
Cast supports many people and many agents. Every message arrives with a verified identity. Each person is assigned to a channel with its own permissions: what they can ask, what they can see, whether they reach the agent at all.
Cast doesn’t define what an agent can do. It gives you the primitives to build whatever you need done.
Both produce the same folder under ~/.cast/agents/. Start in one, finish in the other.
Design is a chat in the dashboard. Describe the agent you want and it writes the folder. The build consoles run contained: the one that designs never sees your secrets, the one that holds secrets never reaches the internet. When one stalls, the files are right there to edit.
Three skills load Cast’s file formats and workflows into a session: /cast-build to author, /cast-refine to grow a running agent, /cast-debug when something is off. Full access to your machine, every change through your review.
The program, the source, and the folder your agents live in all sit on your disk. If this project vanished tomorrow, you would keep all three.
Clone it, boot it, describe one job in plain English. Let it run for a week, then decide what else to give it.