rohaga

hey everyone, I’m the author of this blog post, happy to answer any questions in this thread!

Since we fan out in parallel, by definition the latency is only at worst the latency of the slowest model. The model in between is fairly light, so it seems to not materially affect things. Deciding mid-turn also lets us resolve earlier, often saving on the latency question. We hope to publish a detailed study about this soon.

We are exposing the routing decision information already, scroll over the response in the Dashboard and it'll tell you what models it considered and what it chose.

Yeah this is a great observation--we have to collect some more data to understand new models as they come out. However, by having this composable architecture that separates "confidence prediction" and the actual "routing layer," this makes it a lot easier to add new models/restrict the models rather than re-training from scratch.

I agree that adjusting the reasoning effort to retain cache is a huge thing! But even doing that automatically is currently a challenge for people to figure out and do well, and costs mental energy when perhaps it doesn't need to. For example, there is GPT-5.6-Sol low, med, high, xhigh, max, and lots of "rules of thumb" that people develop on which one to use when.

It automatically works with multi-turn routing. You can try it yourself in Claude Code or Codex

Thanks for the praise!

We think the results are a work in progress. Routing is convincing for quality for the following reason. Take your favorite benchmark, and on each task, run both the top GPT and top Claude model, and call the task a success if at least one of them succeeds. You'll find the accuracy is SIGNIFICANTLY than just max{GPT, Claude}. And the more models you add the better the effect.

Hence, if we can make the router approach this "oracle," the quality could be really good (but also, with turn-by-turn routing, there's no reason we couldn't exceed the oracle)

We will likely do some ablations. Our approach was SOTA back when we first applied to YC with it, we just neglected to post it (we had only done stuff with tiny Qwen models at that point).

Well, you can estimate the confidence BEFORE you start the task, too. That way you can restrict your trajectory to just a few models.

We also think there are tons of people working on "context management"--e.g. retrieval systems, prompt compression, log compression, etc. We want to work harder on the "decode" side as we think there are lots of savings to be made

If we cut off an unconfident/expensive model early in thinking, then we don't have to pay for additional thinking cost at all. For many tasks, this is quite a large saving.

That being said, whatever models we select to race at any point will ALL have their cache updated, so if they're chosen on the next race they'll be a lot cheaper.

> So this only switches models if the cache is cold

Not exactly. It can also make sense if the cache is hot to switch models. For example, we might currently be on Deepseek and the next task is SO HARD that it doesn't make sense to not use frontier (1 turn to crack versus 100 turns for Deepseek to crack). Likewise, the router may judge that it's likely that the next few set of tool-calls will be ridiculously easy, and so switching to Deepseek will save over time.

Remember that Deepseek can be something like 30x cheaper even cold.

There is a more fine-grained view of caching here, because each model can have a different amount of the prefix already cached as well (since we were switching a bunch) so even if the cache is somewhat warm it may make sense to switch.