The top headline I saw this morning was “AI should earn its keep: Introducing the AI Productivity Guarantee.” Catchy. Every vendor is suddenly racing to promise measurable output instead of vibes, and I get why, because buyers got burned by a year of demos that fell apart the second real work touched them.

But a guarantee is a promise about the worst case, not the demo. And the worst case for most browser agents is depressingly boring: it logs itself out.

The thing that breaks isn’t the model

You watch the agent open Gmail, read three threads, start drafting a reply. Then it navigates to your CRM to pull a name, comes back, and the tab is a login screen. Session gone. The agent now stares at an OAuth wall like it’s the first time it’s ever seen the internet.

This happens because a huge share of agents don’t run in your browser. They run in a fresh, sterile browser somewhere on a server, and that browser carries no history with your accounts. So every navigation is a roll of the dice on whether the cookie survives, and every restart wipes the slate clean.

I saw a Reddit thread last month where someone described their relay agent dropping its authenticated session something like four times in a single workflow. Four. Each time it cheerfully offered to “help you log in again,” which is the digital equivalent of a contractor who rebuilds your front door every time he needs to come inside.

Why does the session keep vanishing?

Because the session was never really there to begin with.

When a cloud or relay agent “controls” a browser, what’s actually persisting your login is a stack of things you don’t own: the cloud browser’s cookie jar, a relay tunnel between their server and some Chrome instance, and a token handoff that has to survive process restarts. Any one of those resetting drops you to square one. The relay reconnects, the cookie jar is empty, and the authenticated state you assumed was sticky turns out to have been rented by the minute.

Re-auth flows are the usual band-aid. Store a refresh token, replay it, re-run the OAuth dance in the background. It works until a provider rotates something, or hits the agent with a device-verification check, or just decides this login pattern looks like a bot. Then the whole “guarantee” quietly depends on a token-refresh job nobody is watching.

Run where you’re already signed in

Here’s the unglamorous fix, and it’s so obvious it almost feels like cheating. Stop spinning up a separate browser. Use the one you’re sitting in front of, the Chrome profile that’s already logged into Gmail and Salesforce and your bank and that one ancient internal tool with a session that’s been alive since March.

That’s the whole pitch behind running an agent as a browser-native extension instead of a remote relay. When the agent operates inside your actual profile, your login state isn’t a thing it has to reconstruct. It’s already loaded, the same cookies the rest of your tabs use, sitting in the same session store, surviving navigation and restarts for exactly the same reason your email stays open when you close and reopen a tab: because it’s a normal part of the browser, not a fragile bridge bolted onto the outside of one. Dassi works this way, living in the side panel of the browser you already use, so when it moves from Gmail to your CRM and back, it’s the same authenticated session the entire time. No token replay, no re-auth job, no silent failure mode hiding behind a productivity SLA.

We dug into the mechanics of this in Your AI Browser Agent Can’t See That You’re Logged In, if you want the longer version. The short version is that “already logged in” is a feature you can only get by being in the right browser.

A guarantee is only as good as its weakest restart

If your agent can’t survive a navigation, every output metric on top of it is built on sand. Damn near every “guaranteed productivity” claim assumes the agent stays authenticated long enough to finish the job, and nobody puts that assumption in the marketing copy.

So before you trust a number, ask what happens on restart. The honest agents won’t flinch, because for them nothing special happens. The session is just there, the way it is in every other tab.

You can try the browser-native version yourself: Dassi on the Chrome Web Store. It’s free, it brings your own key, and it does not forget who you are between two clicks.