Runway shipped a model router this week. If you missed it, the idea is simple: instead of you picking which generative model to use for a given clip or image, Runway looks at the task and picks the model it thinks will do best. Video here, stylized frame there, something fast for a rough cut.

I found this more interesting than the usual product launch, and not because I make a lot of AI video. Because of what it admits.

What a router actually concedes

A model router is a company saying, out loud, that they don’t have one model that wins. If they did, they’d route everything to it and skip the whole apparatus. Runway operates in a space that got crowded fast, with new generative media models landing every few weeks, and their answer wasn’t “use ours for everything.” It was “let us switch for you.”

That’s a real shift in posture. For two years the pitch was pick our thing and stay. Now the smart players are building the switching in as a feature, because the alternative is watching users leave the second a better model drops somewhere else.

So routing is becoming the norm. Fine. But there’s a version of this that matters way more for the work most of us actually do, and it isn’t happening inside a video tool.

The same logic, aimed at your browser

Think about the tasks a browser agent handles in a normal day. Drafting a reply to a client email. Pulling line items out of a vendor invoice that’s open in another tab. Filling a 40-field insurance form. Reading a dense pricing page and telling you what changed.

Those are not the same task, and no single language model is best at all of them. GPT-5.2 is sharp on tight reasoning and following finicky instructions. Claude tends to be steadier on long, structured extraction where you can’t afford a hallucinated field. Gemini 3.1 Pro is fast and cheap enough that you’d happily throw it at bulk work you’d never pay premium rates for. And that ranking shuffles every time somebody ships.

Runway’s move says routing beats loyalty in generative media. The same thing is true for browser work, except almost nobody lets you do it. Most AI browsers hardwire you to one backend. You get whatever model the vendor cut a deal with, running on the vendor’s servers, and when a better model comes out you wait for them to integrate it. Or they never do.

BYOK is just the router you control

This is the part where dassi’s whole design starts to make sense.

Dassi is a Chrome extension that runs an AI agent in your browser side panel, and it doesn’t ship with a house model you’re stuck with. You bring your own key. Claude, GPT, Gemini, DeepSeek, whatever you’ve got a key for. You log in with your existing ChatGPT subscription if you don’t want to touch an API key at all. Then you pick which model drives which task.

So the router isn’t a black box some company runs on your behalf. It’s you. Extracting a table of transactions? Point it at Claude. Need a quick summary of the page and you’re watching cost? Gemini. Something gnarly that needs real reasoning? GPT-5.2. Same agent, same tab, different engine, and you flip it whenever you want. We wrote more about why locking yourself to one provider is a bad bet in AI Data Mining Makes BYOK Essential.

And here’s the piece a video tool doesn’t have to think about: the browser context. When dassi runs a task, it runs in your already-logged-in tab. Your Gmail, already authenticated. Your CRM, already open. No server round-trip, no cloud browser spinning up a fresh session that has no idea who you are, no re-login. The model changes; your session state doesn’t move an inch.

Loyalty is the expensive option now

Runway wouldn’t have built a router if betting on one model were safe. It isn’t, and it’s less safe every month the field gets more crowded. A model that’s clearly ahead today gets matched or beaten by something else before your annual contract is up, and if your tool welded you to the loser, that’s your problem, not the vendor’s.

BYOK on a browser agent is the same insurance, aimed at the work that pays your bills instead of the work that makes pretty clips. You keep the option to move. When GPT-5.3 or Claude Opus 5 or Gemini 4 lands, you switch that afternoon and don’t ask permission. If you’ve been putting off trying this, dassi is on the Chrome Web Store and it’s free.

Routing won generative media faster than I expected. The tab you’re reading this in is next.