01In plain English
A kill switch is a control that stops an AI agent or automation at once, even in the middle of a task. It can be a button, a setting that revokes its access, or a rule that halts it when something looks wrong.
02How it works
A kill switch is a control placed outside the agent, so the agent cannot ignore it. In practice it takes one of three forms. The first is a stop button in the tool's dashboard that halts every running task. The second is revoking the agent's access, for example by disconnecting its email account, which cuts off its hands without needing the agent's cooperation. The third is a rule that stops the agent by itself when something trips a limit, such as too many emails sent in an hour or spending above a set amount. Picture a delivery driver who has made a wrong turn: the dispatcher can radio them to pull over, or cancel the company card they are using.
03Why it matters when you are choosing
An agent acting on your behalf can repeat a mistake many times before anyone notices. A kill switch limits the damage to what happened before you pressed it.
04What to check
Ask how you stop the agent, who can do it, whether it stops actions already in progress, and whether you get a record of what it did.
05Where you will meet it
06Common questions
Does a kill switch undo what the agent already did?
No. It stops further actions, but anything already sent, posted or deleted stays that way. That is why logs and approval steps matter as well. A good setup lets you see what was done before the stop, so you can fix or reverse the damage by hand.
Who should be able to press the kill switch?
More than one person, and not only the person who set the agent up. If the owner is asleep or on leave, someone else on the team needs the access to halt a task that is going wrong. Many tools tie this to admin roles, so check who holds them.
Is pausing an agent the same as a kill switch?
Not always. A pause may let the current task finish, while a true kill switch ends actions in progress. Ask a vendor which one the button does, how long it takes to take effect, and whether it also blocks scheduled runs that have not started yet.