Mark Gurman’s column last week about Apple turning iOS 27 into a “Choose Your Own Adventure of AI models” landed in my feed and my first reaction was relief. Apple is finally going to let users pick Gemini or Claude or ChatGPT instead of dragging Siri into every interaction. And fifteen years of “our stack is the stack” cracked open by a dropdown.

So the marketing team gets BYOK. Sort of.

Half of what BYOK meant

When developers started saying BYOK a couple of years ago they meant something fairly specific, and a model picker is not it. They meant the keys are mine, the model runs against my real context, and the data flows through pipes I can audit if I feel like checking. Three things stacked. But Apple’s iOS 27 angle hands you the first, throws in a half-credit on the second by maybe letting you plug in your own subscription, and ignores the third entirely.

Because the chosen model still lives inside Apple’s sandbox. It summarizes your messages, rewrites email drafts, and pokes through whatever surfaces App Intents decides to expose at WWDC, a list that has historically been small, politically negotiated, and shaped by whichever partner agreements the App Store team is willing to sign that quarter. So it does not see your browser. And it does not know you are logged into Salesforce, that a Linear ticket sits open in another tab, or that a half-finished expense form has been waiting since Tuesday afternoon for somebody to dig up the project code. The picker is real BYOK at the model layer and pure theatre everywhere else.

What r/apple was actually asking

A thread on r/apple had somebody ask, paraphrased: if I can pick Claude on my iPhone, why am I still paying twenty bucks a month for Claude.ai? Nobody named the answer cleanly but the replies kept circling it. Claude.ai sees your uploaded files and the rolling conversation history. iOS Claude sees a thumbnail.

Same brain, different eyes

Three model brains, all functionally equivalent. Different eyes. The picker swaps the brain. But nothing in iOS swaps what the brain can look at.

Context is the part that won’t move

Switching between GPT-5.2 and Opus 4.7 and Gemini 3.1 Pro on a clean prompt is a benchmark exercise dressed up as a productivity story. So I run this comparison most weekends and it tells you damn near nothing about what the model will do once it can see your actual logged-in work. The hard problem, the one no consumer platform is shipping, is getting any of those models close enough to your real session to do something useful with it.

Model choice is cheap and getting cheaper. But context refuses to budge, because moving it means handing a third-party agent your authenticated browser, and Safari is the last permission Apple has any interest in giving away. We wrote about this from a different angle a few weeks back, back when WWDC rumours were still pretending Apple Intelligence was about to grow eyes. It hasn’t. It won’t this year either.

So where dassi fits in this picture

Dassi is a Chrome extension. You log in with your existing ChatGPT subscription, or bring your own key for Claude, Gemini, DeepSeek, whichever. And the model you pick reads the page you are already on. Gmail you are authenticated into. The Notion doc you have open. The dashboard you spent ten minutes filtering down to the view that actually matters.

Both halves at once. The model picker Apple is finally normalizing, and the context layer Apple has no story for. Install dassi from the Chrome Web Store and point it at whatever tab is open right now.

Why model choice photographs better than context

Because Tim Cook holding up a slide that reads Claude, Gemini, ChatGPT in matching sans-serifs is a keynote moment. Context, the boring useful version of it, refuses to fit on a slide. You would have to show real screens with real logged-in state and most of those are either under NDA or quietly humiliating.

Cloud-side agents have the inverse problem, where a vendor’s model runs in a vendor’s container against a vendor’s generic context and never sees yours, which is the point we keep returning to about session location being the actual lever. So a model that lives elsewhere fixes nothing if your work lives behind your login.

What iOS 27 actually changes

It normalizes the vocabulary. People are about to learn “model picker” the way they learned “incognito mode” back around 2010. And once users accept they can swap models, the obvious next question shows up. Against what.

Apple will not answer that one well. Their picker sees only what App Intents permits, and the browser stays politely off-limits.

iOS 27 is the setup line. Browser agents have been telling the punchline for a year already.