Solar Mini 4 Hermes: How To Run It Free, And How It Compares With The Benched Hermes Brains

By Julian Goldie · 2026-10-07 · GoldieBench Blog

Solar Mini 4 Hermes means running Upstage's new Solar Mini 4 model as the brain of Hermes Agent, and right now you can do it for free on Nous Portal.

I run GoldieBench, the leaderboard where 40 models have produced 1,609 one-shot demos across 50 tasks.

So this post does two jobs for you.

First, it shows you exactly how to set up Solar Mini 4 inside Hermes without landing on the paid version.

Second, it uses real numbers from the board to show you which Hermes brains have actually earned their place, and where a model like Solar Mini 4 would fit.

I'll be upfront about one thing straight away.

Solar Mini 4 is not on the GoldieBench leaderboard yet, so I won't give it a score it hasn't earned.

What Solar Mini 4 is, in short

Solar Mini 4 is a compact model from Upstage AI in South Korea.

It's a mixture-of-experts model with 35 billion parameters in total and 3 billion active at a time.

Its context window is roughly 500,000 tokens, and OpenRouter lists it at 524,288.

Artificial Analysis gives it 24 on its Intelligence Index, which it says is one point above Nemotron 3 Ultra with 55 billion active parameters.

Artificial Analysis also describes it as proprietary, so there are no weights to run locally.

It's free for two weeks on Nous Portal, the Nous Research portal that Hermes Agent connects to.

The full model background lives in my Solar Mini 4 explainer, so I'll keep this part short.

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How to set up Solar Mini 4 in Hermes

There are four routes, and all of them end with a Hermes profile running the free model.

The one thing you must do is pick the free variant.

Set main model shows a free Solar Mini 4 and a paid one next to each other, and the paid one bills you.

If the model is missing from your list, refresh it, or run hermes model --refresh to re-fetch every provider's live model list.

I keep one profile per model, and hermes profile create solar-mini-4 is how you make one from the terminal.

How Solar Mini 4 did in my first Hermes tests

I typed "test" into a fresh profile, and it replied fast and confirmed the session was live with memory switched off.

Then I asked for the latest AI automation news from the last seven days.

It came back quickly with a breakdown, sources and a "what stands out" section, including an Oracle launch I hadn't heard about.

That's a good result for a free model on a basic agentic task.

It's still not frontier level, and it isn't in the same league as Claude Opus 5.5 for hard work.

One viewer also told me it ran badly for them, so quality varies by task.

What GoldieBench measures, and what it doesn't

Every model on the board gets the same one-shot prompts to build games, pages, simulations and visuals.

Each build is rendered and scored from 0 to 10, and the scores you see are averages across those tasks.

That's a strong signal of how well a model plans and writes working code in one go.

It is not a direct test of agent loops like web research inside Hermes, so treat it as one input, not the whole answer.

Still, a brain that can't build reliably in one shot usually struggles on long multi-step agent jobs as well.

The best Hermes brains on the board right now

These are the top single models and set-ups on the live board, with the price each one lists.

Hermes MoA is worth a special mention here, because it's Hermes Agent's own Mixture of Agents mode.

It scored 8.17 across 47 tasks, with 3 golds, 10 silvers and 2 bronzes.

That tells you Hermes itself can sit at the top of the board when you give it strong brains to combine.

For value, MiniMax M3 at 7.97 and GLM-5.2 at 7.77 are the ones I'd look at first.

The free Nous Portal models: which ones are benched?

When I recorded the video, the free list in Hermes Cloud showed six models next to Solar Mini 4.

Here's where each of them stands on GoldieBench today.

The two free models I can give you numbers for sit at opposite ends of the board.

LongCat 2.0 averaged 8.12, but only 4 tasks are scored, which is why the board marks it provisional.

Laguna XS 2.1 averaged 3.93 across 42 tasks, which is a much bigger sample and a much weaker result.

Where Solar Mini 4 would fit

I haven't benched Solar Mini 4, so I'm not going to guess a number.

What I can do is tell you how I'd think about it, based on what the board shows for models of a similar shape.

It's a 3-billion-active mixture-of-experts model, and that size class is built for speed and price rather than depth.

On the local side of the board, Agents-A1 is also a 35B mixture-of-experts model with about 3B active, and it averages 4.83 across 45 tasks.

Agents-A1 runs locally and Solar Mini 4 is hosted, so they aren't the same thing, but it shows how hard one-shot builds are for small active-parameter models.

Solar Mini 4's own Intelligence Index score of 24 suggests it's strong for its size, and my research test backed that up.

So my working view is simple: put it in the fast lane for research, summaries and sorting, and keep the heavy builds on a model from the top table.

Free versus paid Hermes brains: what the gap really costs you

The board makes one thing very clear, which is that the top scores still belong to paid models.

Claude Opus 5 lists at $5 per million input tokens and $25 per million output tokens for its 8.27 average.

GPT-5.6 Sol lists at $5 per million input and $30 per million output for its 8.16 average.

MiniMax M3 lists at $0.30 per million input and $1.50 per million output, and it still averages 7.97.

That last row is the one I'd stare at if you're watching costs.

MiniMax M3 gets within about three tenths of a point of Claude Opus 5 at a small fraction of the input price.

A free model like Solar Mini 4 sits below all of that on price, because during the promo it costs nothing at all.

The trade is depth, and the board shows that trade over and over again in the smaller models.

So the smart move isn't picking one brain for everything.

The smart move is giving each Hermes profile the cheapest brain that can actually do its job.

How to test Solar Mini 4 in Hermes yourself

Until Solar Mini 4 has a GoldieBench score, your own test is the one that counts.

Here's the simple plan I use for any new free brain.

The small build row is the closest thing to a mini GoldieBench task you can run at home.

If a model fails it, keep that model away from coding jobs in your Hermes setup.

If it passes all five, it has earned the fast lane.

Rate limits and switching between free brains

Free models are shared by a lot of people, so they get rate limited at busy times.

You'll notice slow replies or errors partway through a job when it happens.

Refresh the model list first, because a missing model is usually a stale cache rather than a removed model.

Then switch the profile to another free model, such as Step 3.7 Flash or Ling 3.1 Flash, and finish the job.

Switch back to Solar Mini 4 later, once the queue has calmed down.

This is why I keep one profile per model, because swapping brains becomes a single click.

The Hermes brain plan I'd use today

Free models get rate limited, so the backups in the first lane matter.

If Solar Mini 4 slows down or vanishes, refresh the list, switch the profile, and come back later.

The free window is two weeks, so build each profile so the model is one setting you can change.

If you want my older, deeper ranking, the best LLMs for Hermes Agent post covers more of the board.

Also On Our Network

🌐 the step-by-step Solar Mini 4 Hermes setup for operators

🌐 how businesses use Solar Mini 4 inside Hermes

🌐 our scored verdict on Solar Mini 4 as a Hermes brain

🌐 the Solar Mini 4 Hermes quick start for your Agent OS

🌐 Julian's guide to running Hermes free forever

Pick the free variant, give it the fast lane, and watch the board for the day Solar Mini 4 Hermes gets a real GoldieBench score.

FAQ

Related reading

→ The Best Local Model For Hermes Agent — Decided By 45 Real Builds

→ The Best LLMs For Hermes Agent, Ranked By Real Work

→ The Best Free AI Model For Hermes Agent (All Three $0 Lanes)

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