116 points adam_rida 2 hours ago 52 comments

I’ve been building Echo (https://echo.tracerml.ai/), an experiment in making one AI system out of a pool of open-weight models rather than choosing a single model and using it for every task.

It started with a simple experiment. I took a group of models, including GLM-5.2, Kimi K2.7 and others, and ran them on the same evaluations. Then I measured what would happen if, for each problem, you somehow knew in advance which models would be useful and how their outputs should be combined.

That hypothetical system performed substantially better than any individual model in the pool. Of course, it is not something you can actually deploy because it relies on knowing which decisions were good after seeing the result. Echo is my attempt to recover some of that advantage without having that information in advance.

For each request, Echo decides how much computation to allocate, which models should participate, and how their work should be combined. Some prompts may only need a relatively small amount of inference, while others benefit from multiple models working on different parts of the problem.

One thing that surprised me while building it was how complementary the models are. A model that is clearly weaker overall can still be extremely useful on particular problems or as part of a combination.

On my first evaluation mix, Echo consistently performed better than the best individual model in its pool. It also reached roughly the same aggregate result as Fable, which I used as one of the stronger comparison systems, at around one third of the inference cost.

There are still some cases where Echo makes the wrong allocation or combination decision. I’m currently spending a lot of time understanding those failures, as well as testing whether the same approach holds up on coding and agentic tasks where measuring the quality of each decision becomes much harder.

I built a chat interface (echo.tracerml.ai) and an OpenAI-compatible API (https://echo.tracerml.ai/docs/api) so the system can be tested outside the evaluation setup.

Here is a short/high level video on how it works: https://www.youtube.com/watch?v=lJFJSvOdXhg

I wrote up the evaluation methodology, individual model results, costs and current limitations here: https://echo.tracerml.ai/eval

I would love for you to try it! Especially if you hit any weird failure cases or places where the allocation looks unintuitive.

kamranjon 1 hour ago | parent

No benchmarks, no info on which models are used, ai generated video, just a signup page with nothing else.

Anyhow, this kinda reminds me of that quote about architecture: "We replaced our monolith with micro services so that every outage could be more like a murder mystery."

guessmyname 1 hour ago | parent

> No benchmarks, no info on which models are used, […]

The benchmarks are here → https://echo.tracerml.ai/eval/

They are not good benchmarks but at least they exist.

seizethecheese 52 minutes ago | parent

I've been working on a similar project and I found that it's easy to replicate Fable results if you use saturated benchmarks.

In my project, I wasted a huge amount of time trying to improve GPQA Diamond results above ~93% range. I realized my mistake when Fable dropped and made no improvement on this benchmark vs. Opus.

j45 1 hour ago | parent

It's easy enough to copy and paste in a prompt, no?

Eval tests while giving general indicators might not be similar for each use case.

adam_rida 1 hour ago | parent

The evaluator is public here: https://echo.tracerml.ai/eval/

It currently exposes 907 stored rows across seven benchmark families, with prompts, outputs, grades, and cost records. More benchmarks are coming soon.

Echo does not disclose its per-request routing decision because that policy is the product. We can, however, publish some of the eligible open-weight model pool, version dates, aggregate allocation mix, and evaluation settings without exposing the request-level recipe.

New video is also being made.

codekansas 1 hour ago | parent

It's basically trying to replicate OpenRouter, which works pretty well and has a lot of nice features to abstract away any single provider, such as failover, metering, autoswitching, etc. It's actually a really smart infrastructure abstraction.

I just wish this were solving an actual problem rather than being a fairly transparent attempt to say something approximating, "Hey VCs, OpenRouter just became a unicorn but I can basically vibe code it"

Calling it "Fable-level" feels intellectually lazy / dishonest, but then again, what do you expect when there's so much money on the table.

seizethecheese 29 minutes ago | parent

OpenRouter's model router for coding isn't really sophisticated. This is very different.

dimitrios1 20 minutes ago | parent

Unrelated - but reminds me of my favorite quote by tenderlove:

"microservices turn function calls into distributed computing problems"

WD-42 3 minutes ago | parent

grug wonder why big brain take hardest problem, factoring system correctly, and introduce network call too

seem very confusing to grug

tj800x 1 hour ago | parent

No single signin. Privacy policy allows training. No try it first without credit card. It's a good idea, but this looks premature.

adam_rida 1 hour ago | parent

You are right that the privacy wording was too broad. We are fixing it now so it states explicitly that Echo does not use customer prompts, files, chats, or outputs to train or fine-tune models. We are updating the matching Terms language at the same time.

Echo also starts users with free credit and does not require a credit card to try it. The current signup flow did not make that clear enough, so we are fixing that presentation too.

Thanks for calling both out.

cynicalsecurity 46 minutes ago | parent

I assume trying without a credit card will bankrupt him immediately.

seizethecheese 27 minutes ago | parent

If you want to try a similar idea that you can chat with immediately (free tier uses open weight models), I'm working on this: http://pellmell.ai

fneddy 1 hour ago | parent

That’s basically the same idea IBM advertises with Bob?

jmaw 1 hour ago | parent

I think approaches like this have potential. Only time will tell. This reminds me of the mixture of experts taken by deepseek r2 (I think it was r2, at least), but less specific models I guess.

I have often wondered how tools like GHCP choose the best model for the job when set to "auto".

Alifatisk 1 hour ago | parent

This reminds me on OpenRouters report that combining multiple different models gave comparable performance to Fable 5. I think this approach has lots of potential. Maybe OpenAi was ahead of its time with GPT-5 (it being a router to different models rather than just being one new model)

seizethecheese 55 minutes ago | parent

You might be interested in a project that I'm working on, which is kind of like OpenRouter Fusion, but instead of waiting for all models to synthesize, we stream the best model immediately and background the rest. The background models then reconcile with an emoji reaction and optional reply. It gets similar results to Fusion and is a lot faster! There's a free version that leverages open weight models here: http://pellmell.ai.

hmokiguess 19 minutes ago | parent

This is really cool, super fun!

j45 1 hour ago | parent

If you copy Perplexity, they let you have the first few rounds of chat for free to get you going before asking to sign up.

codekansas 1 hour ago | parent

Fable-level, yea, but can it run gstack?

jambalaya8 1 hour ago | parent

Might want to rethink the name to avoid an Amazon issue.

wizche 1 hour ago | parent

how does this differs from OpenRouter fusion?

cawingcrow 1 hour ago | parent

how does this differs from Sakana Fugu?

adam_rida 50 minutes ago | parent

Fugu includes closed source models in its pool

bnjemian 1 hour ago | parent

I don’t find the recent spate of blog posts and systems delegating and combining LLMs to get better performance particularly interesting. Especially given that anyone who’s taken an ML 101 course has learned about ensemble methods.

While an LLM isn’t what you’d traditionally consider a weak learner, the theorems on learning systems clearly point to them being so in this context. The feigned surprise at combining them to yield better results seems disingenuous.

Even so, the work to predict which models are best suited for which task, how to delegate, and how to combine their outputs is interesting, especially if you’re placing a cost minimization objective on it. That said, this isn’t too far off from what many AI labs are already doing.

abernard1 57 minutes ago | parent

The entirety of "agents" and tool calls is a process of combining LLMs to get better results. Is it the same LLM in many cases? Yes. But it doesn't have to be.

It's the natural move that happened after people realized you couldn't throw away half a century of AI research.

Most of these focus on costs. But it is simply the case that the one-shot output did not scale for harder problems on workflows.

ototot 1 hour ago | parent

Is this yet another Sakana Fugu / OpenRouter Fusion?

kachnuv_ocasek 34 minutes ago | parent

Looks like it but with open-weights only.

yonatan8070 1 hour ago | parent

I'm not an expert on this, but this sounds a lot like a larger-scale MoE (Mixture of Experts) type of architecture.

As I understand it, in an MoE model, you essentially have hundreds of smaller sub-models ("experts") that are good at different tasks, and for every generated token, a single "master" model chooses which ones are most relevant to participate, and you only activate them.

janalsncm 58 minutes ago | parent

In MoE systems the routing decision is made per-token, not per prompt or task. It’s one of ML’s many confusing naming conventions.

Even more confusingly, there are older pre-LLM MoE systems which ensemble and pool the predictions from multiple sub-components. For example in a random forest you could take the majority vote of the decision trees or the average of their numerical predictions.

After that, we developed neural net architectures for predicting a single thing like whether the user will click on your ad. An MMoE is in the same family.

And so now we are at massive MoE networks for LLMs which have similarities with MMoE in that the “decision” is about the very next token to predict.

lukan 4 minutes ago | parent

"In MoE systems the routing decision is made per-token, not per prompt or task."

Have there been experiments with doing it per task? Like, "oh this is python project, use this model" "oh this is about writing fantasy, use this"?

bbstats 50 minutes ago | parent

M-o-MoE

maxdo 47 minutes ago | parent

such a scam, there is only one fable-like model, that somewhat behind, it cost half, not 3x. so from here you can stop reading.

janalsncm 47 minutes ago | parent

Intuitively, your savings depend heavily on how hard the tasks are in the first place. If you have a base rate where 99% of your tasks can be routed to a cheap model, yeah, you can save a ton by not using Fable for that.

So “1/3 the cost” really depends.

ninjahawk1 44 minutes ago | parent

I’m very confused on what this is, my initial thought was “oh nice, open source router.”

I go to the website…and it’s a sign up. I expected a repo. Otherwise how do I use it? As a SaaS? Yeah right.

Oh well I guess at least the benchmarks are good…I find the benchmarks and many are either not present or are not what the title claims.

My main question is how this has so many updoots from HN, probably the passerby not looking closer for sure.

I mean no offense and I really do wish you best on this, but it seems like what we used to call back in the day, vaporware.

jacobgold 42 minutes ago | parent

> Fable-level results at 1/3 the cost using open-weight models

But we get ~$2500/mo worth of Fable credits for $200/mo on Anthropic pan? I'm still confused why people (who don't have to use API billing) are chasing open weight models based on cost.

teruakohatu 39 minutes ago | parent

Because that is a short term solution, it won’t be offered forever. Large organisations have to purchase credits at $/tokens. Eventually everyone else will too.

sscaryterry 31 minutes ago | parent

This is what OpenAI and Anthropic are trying to make everyone believe. Most accountants will flinch at this (they already are).

The $200 odd plans are already out of reach of many, many people.

The attrition of customers if they were to get rid of these subscriptions plans would be untenable.

recursivegirth 18 minutes ago | parent

I think you are looking at it incorrectly. No business is buying individual accounts, because if they do, they open themselves up to considerable risk.

The $200 plans are priced so that the power-users use them and then advocate about how great the product is. If you're buying a $200 plan, you're not doing it because of the price point but rather because of the amount of work it is doing for you.

dberg 36 minutes ago | parent

doesnt exist for enterprise plans

combyn8tor 30 minutes ago | parent

You may want to consider the incomes of developers outside the US, students, unemployed. $200/month is a lot to a lot of people.

dbbk 28 minutes ago | parent

They can still write code.

gruez 28 minutes ago | parent

The point still stands. The chinese labs don't have super discounted plans, so if the price per task benchmarks[1] are correct, and we apply the discount, you'll actually be paying more by using cheaper chinese models and this technique.

https://artificialanalysis.ai/agents/coding-agents#artificia...

recursivegirth 30 minutes ago | parent

Enterprise plans pay API costs, they're only subsidizing individual accounts and that's only because they have to compete with open-source models.

When they are successful at making those illegal/inaccessible, both Anthropic and ChatGPT are going to rip the band-aid off and inference will only be sold to those that can afford it.

The good ole American way.

drnick1 24 minutes ago | parent

> When they are successful at making those illegal/inaccessible

This would be like trying to outlaw Linux or peer-to-peer file sharing. It's technically possible to write and pass a law, but it's basically impossible to enforce it.

switchbak 20 minutes ago | parent

Enough to make it a non-started at the organizations that pay their bills. Everyone else isn't big enough to matter.

dluan 30 minutes ago | parent

So this is the dogpile.com of the askjeeves, alta vista, and lycos approach? Time is a flat circle?

hmokiguess 25 minutes ago | parent

"Backed by YCombinator"

https://www.ycombinator.com/companies?query=tracerml

I don't see it?

adam_rida 20 minutes ago | parent

haven't done yet the public yc launch, currently in s26