Project HydraFusion: Frontier quality via multi-model orchestration

> One model drafts a result, an independent read-only critic from a different model family reviews it

Multiple model vendors is key here, the cascade pattern doesn't need it, but the critique pattern does.

Last Nov, my team wrote a paper ("Team of Rivals") on the difference between using an OpenAI model to Critique an Anthropic model's output vs running a self-review agent loop on the same vendor.

The ablations [1] proved that neither company alone was better than using both.

The paper was a general response to "What does your company do that Anthropic can't?" but more so a demonstration of how to make something 90%+ good with models which eval at 60% or so (& Gas Town post unblocked our "this is a trade secret" argument about the paper).

[1] - https://github.com/t3rmin4t0r/critique-evals

I'm questioning their results. It doesn't take much to beat the frontier in single benchmarks if one puts extra software between the model and the harness.

This is also a reason why comparing "naked models" for which weights are available and frontier where providers can do whatever they want behind the scenes is unfair.

Specifically, all it took to boost Qwen3.8-27B to get 10% more points on SWEbench Pro and Terminal Bench 2.0 with a proxy that has just these basics: - tweaks few decode settings like slightly higher temperature - detects when model gets stuck and tells it to "go on" - detects responses cut in the middle, empty responses that contain only reasoning, formats not passing verification etc and tells the model to "try better"

And that is it. 10% more. I admit on a subset of tasks, but results are results, even on a subset.

i've been using adversarial critique and reviews for many planning, solution design and implementation steps inside workflows.

It's so effective and helps catching so many design flaws, implementations misses etc ... that i'm wondering how people manage to build complex/large projects with agents without this kind of process. Well, i actually built this thing because i couldn't get good results so i had to find a way.

I'm gonna open source the whole thing but it needs some cleanup, there's a basic landing page here https://kodfactory.com if anyone wants to be notified when it's released on github. Yeah i know, the world really needs another software factory :-)

This has got to be the worst project name I've seen all year.

This looks very similar to what I've seen with a different harness - https://github.com/AMAP-ML/LongHorizon-Harness. It's critique pattern looks like another version of lh-harness without looping toward an overarching goal

They should probably focus on “project hydrastable infrastructure” instead

I have a custom agent that I call my "G.S.D." (Get Stuff Done) agent.

It is explicitly not a foreman, task routing, or an orchestrator agent. It has a bias toward direct action and is instructed to only delegate when necessary.

I've found that this approach yields significantly faster results, without much of a quality trade-off, than an agent whose primary impulse is to delegate.

In contrast, HydraFusion starts with a task routing step, then sequential planning, execution, and review stages. My guess is that this workflow is best for people who are prioritizing cost over speed for the same level of quality.

that's crazy

From the article:

> In controlled offline evaluations, HydraFusion’s selective coding workflows matched or exceeded the evaluated Opus 5 baseline

Opus 5 (in practice) is not a good baseline to compare against.

I'm shocked that they chose to primarily compare against Opus 5 in all the article's charts. It's pretty disingenuous that they're claiming "frontier" quality, but didn't compare against Fable or Sol.

Maybe I'm just 2026's Dropbox guy, but... yes, and?

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