Solar Mini 4 Hermes is the setup I use to run Upstage's new Solar Mini 4 model as the brain of Hermes Agent for free, and this page walks you through every route step by step.
Solar Mini 4 is a small, fast model from Upstage AI in South Korea, and right now it's free for two weeks on Nous Portal.
Nous Portal is Nous Research's own model portal, and it plugs straight into Hermes Agent.
So you can give your agent a fresh brain today without paying for a single token.
I'll show you four ways to set it up: Hermes Cloud, Hermes Desktop, the Hermes dashboard and my Agent OS.
Then I'll show you how I tested it, where the rate limits bite and the one setting you must get right or you'll end up on the paid version.
What Solar Mini 4 Hermes Actually Means
Solar Mini 4 Hermes simply means running Upstage's Solar Mini 4 model as the model that powers Hermes Agent.
Hermes Agent is the body, which handles the tools, memory, files and chat.
The model is the brain, which does the thinking behind every reply.
You can swap the brain whenever you like, and that's exactly what I do every time a decent free model lands.
Here's the short version of what Solar Mini 4 brings to the table.
| Fact | Detail |
|---|---|
| Who made it | Upstage AI, a lab based in South Korea. |
| Model type | A mixture-of-experts model with 3 billion active parameters and 35 billion in total. |
| Context window | Roughly 500,000 tokens, which OpenRouter lists as 524,288. |
| Intelligence score | Artificial Analysis gives it 24 on its Intelligence Index. |
| Cost inside Hermes | Free for two weeks on Nous Portal, and the free variant is the one you want. |
| Weights | Artificial Analysis describes it as a proprietary model, so you can't download it and run it offline. |
Artificial Analysis says that score of 24 puts it one point above Nemotron 3 Ultra, which has 55 billion active parameters.
That's the "above models with ten times the active parameters" claim I mentioned in the video.
If you want the deeper background on the model itself, I've covered it in my Solar Mini 4 explainer.
This page is all about getting it running inside Hermes.
Before You Start: What You Need
You need three things before any of the routes below will work.
- You need Hermes Agent installed, or a Nous Portal account if you're going the cloud route.
- You need to be signed in to Nous Portal, because that's where the free Solar Mini 4 lives.
- You need five minutes and a willingness to test it before you trust it with real work.
If you don't have Hermes yet, my guide on how to set up Hermes Agent in one click gets you there quickly.
On the terminal side, hermes portal logs you in to Nous Portal and sets it up as your provider.
That's the same as running the Portal option inside hermes setup, so use whichever you prefer.
Route 1: Solar Mini 4 In Hermes Cloud
Hermes Cloud is the easiest route because nothing runs on your computer at all.
You deploy a Hermes Agent instance in the cloud and point it at a free model.
Here are the exact steps I followed.
- Go to the Nous Portal cloud page at portal.nousresearch.com/cloud and sign in.
- Click to create a new agent.
- Open the model section for that agent.
- Scroll down the list until you see the filter for free models, and click "Free".
- Pick Upstage Solar Mini 4 from the free list.
- Deploy the agent and send it a test message.
That's it, and your cloud agent now runs on Solar Mini 4 without a bill.
While you're in that free list, notice the other models sitting next to it.
When I recorded the video, the free list included NVIDIA Nemotron, Poolside Laguna XS 2.1, inclusionAI Ling 3.1 Flash, StepFun Step 3.7 Flash, Meituan LongCat 2.0 and Upstage Solar Mini 4.
Those are your backups when Solar Mini 4 is busy, and I'll come back to them in the rate-limit section.
Route 2: Solar Mini 4 In Hermes Desktop
Hermes Desktop is the app I use most, so this is the route I'd pick if you're on a Mac or PC.
The trick I use is to create a new profile for every model I test.
A profile is an isolated copy of Hermes with its own settings, model and memory.
That means I can flip between models in seconds without breaking my main setup.
Here's how to do it.
- Create a new profile and name it after the model, such as "solar-mini-4".
- Open the model settings for that profile.
- Refresh the model list so the newest free models appear.
- Choose Nous Portal as the provider.
- Pick Solar Mini 4 from the free models, and make sure it's the free one.
- Start a new chat in that profile and type a quick test message.
If you'd rather create the profile from the terminal, hermes profile create solar-mini-4 does the same job.
Profile names are lowercase, so a name like solar-mini-4 is a safe choice.
Then you can chat in that profile with hermes -p solar-mini-4.
I keep one profile per model because testing a new brain should never put my daily driver at risk.
Route 3: The Hermes Dashboard (And The One Thing You Must Do)
This is the route where most people make the mistake that costs them money.
The dashboard lets you set the main model for a profile from a simple web page.
- Open your terminal and run
hermes dashboard. - The dashboard opens in your browser on your own machine.
- Click on "Models" in the menu.
- Click "Set main model".
- Type "solar" into the search box.
- Choose Nous Portal as the provider.
- Pick the variant labelled as the free Solar Mini 4, not the paid one.
That last step is the one thing you must do.
There are two Solar Mini 4 entries in that list, and one of them is paid.
If you grab the paid one by accident, Hermes will happily run up a bill on a model you thought was free.
So read the label carefully before you click.
If you use my Agent OS, you can reach the same dashboard from the manage section instead of the terminal.
Route 4: Solar Mini 4 In The Agent OS Hermes Tab
My Agent OS has a Hermes tab built into it, and it reads the same profiles you just created.
So once your Solar Mini 4 profile exists, using it here is a two-click job.
- Open the Agent OS and go to the Hermes tab.
- Pick the solar-mini-4 profile from the profile list.
- Chat with Hermes directly, exactly as you would in the desktop app.
This is how I compare models side by side, because I can jump between profiles without leaving one screen.
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How To Test Your Solar Mini 4 Hermes Setup
Never trust a new brain until you've tested it on two things: a ping and a real job.
Test 1: The ping
I typed the single word "test" into a fresh chat.
It came back fast and told me the session was live.
It also mentioned that memory was switched off, which is normal for a fresh profile.
If you get an error here instead, the problem is almost always the provider or the model variant, so go back to the dashboard and check both.
Test 2: A real research job
Then I gave it a real task that I'd normally hand to an agent.
I asked it for the latest AI automation news from the last seven days.
It came back quickly with a clean breakdown, a list of sources and a "what stands out" section.
It even flagged an Oracle launch I hadn't heard about yet, which is exactly the kind of thing I want a research agent to catch.
That's a decent result for a free model doing a basic agentic task.
A test plan you can copy
| Test | What to type | What a pass looks like |
|---|---|---|
| Ping | "test" | It replies quickly and confirms the session is live. |
| Research | "Find the latest AI automation news from the last 7 days with sources." | You get a structured summary with sources you can click and check. |
| Tool use | "Read this folder and summarise the three newest files." | It calls the file tool and summarises the right files. |
| Follow-up | "Turn that summary into five social posts." | It keeps the context and writes usable drafts. |
Run all four, and you'll know in ten minutes whether it's good enough for your workflow.
Rate Limits And Switching To Other Free Models
Free models are popular, and popular free models get rate limited.
When that happens, you'll see slow replies or errors in the middle of a task.
Here's what I do when it happens.
- First, I refresh the model list, because a missing model is usually a stale list rather than a removed model.
- Second, I switch the profile to another free model from the same Nous Portal list.
- Third, I switch back to Solar Mini 4 later, when the queue has calmed down.
hermes model --refresh wipes the model picker's cache and re-fetches every provider's live list, which fixes the "where has it gone?" problem.
This is another reason I like one profile per model.
If Solar Mini 4 is busy, I just open my Step 3.7 Flash or Ling 3.1 Flash profile and keep working.
| Free model on Nous Portal | Made by | Use it when |
|---|---|---|
| Solar Mini 4 | Upstage | You want a fast, free brain for research and basic agent tasks. |
| Step 3.7 Flash | StepFun | Solar Mini 4 is rate limited and you want another quick model. |
| Ling 3.1 Flash | inclusionAI | You want a second free flash model to compare answers. |
| Nemotron | NVIDIA | You want a free option from a big lab as a backup. |
| Laguna XS 2.1 | Poolside | You want a small free coding-flavoured model to test. |
| LongCat 2.0 | Meituan | You want to try a larger free model while it's on the list. |
The free list changes over time, so treat this table as a snapshot from when I recorded.
Honest Notes On Solar Mini 4 Quality
I'll be straight with you about where this model sits.
Solar Mini 4 is not frontier level.
It's not Claude Opus 5.5, and it won't plan a complex build or write a polished long-form piece like a top model will.
What it does well is speed, and the price is zero while the free window lasts.
For basic agentic jobs like research, summaries, sorting and quick drafts, it's genuinely useful.
One viewer left a comment saying it ran badly for them, so quality clearly varies by task and by setup.
That's why I tell everyone to test it on their own jobs before they rely on it.
If it fails your test plan, switch the profile back to your main model and you've lost nothing.
If you want to plug Hermes into other tools after this, my Hermes MCP server setup with Codex is a good next step.
Common Solar Mini 4 Hermes Mistakes
The first mistake is picking the paid variant in the dashboard because it appears first.
Always look for the free label before you click.
The second mistake is changing the model on your main profile.
Make a separate profile, so your everyday agent keeps working while you test.
The third mistake is assuming a missing model has been removed.
Refresh the model list first, because that fixes it most of the time.
The fourth mistake is forgetting the free window is temporary.
Solar Mini 4 is free for two weeks on Nous Portal, so plan for what you'll switch to afterwards.
The fifth mistake is giving a small model a frontier-sized job.
Keep it on fast, simple tasks, and send the heavy lifting to a stronger model.
🔥 Want help picking the right brain for each Hermes job? The AI Profit Boardroom has Hermes Agent training, courses on DeepSeek Harness, Claude Opus 5.5 and Jev AI, and four weekly coaching calls where you can ask me which model to use for what. → Join the AI Profit Boardroom
Related Reading
- My Solar Mini 4 explainer covers the model itself, the specs and every way to access it.
- How to set up Hermes Agent in one click is the fastest way to get Hermes running before you add Solar Mini 4.
- Hermes MCP server setup with Codex shows you how to connect Hermes to your other tools.
Also On Our Network
- 🌐 How businesses and creators actually use Solar Mini 4 inside Hermes
- 🌐 My feature-by-feature verdict on Solar Mini 4 in Hermes
- 🌐 The Solar Mini 4 Hermes quick start for your Agent OS
- 🌐 Where Solar Mini 4 fits against the benched Hermes brains
FAQ: Solar Mini 4 Hermes
Is Solar Mini 4 free in Hermes Agent?
Yes, it's free for now.
Solar Mini 4 is free for two weeks on Nous Portal, which Hermes Agent connects to directly.
You must pick the free variant, because a paid variant sits in the same list.
How do I set Solar Mini 4 as the main model in Hermes?
Run hermes dashboard in your terminal and open Models.
Click "Set main model", type "solar", choose Nous Portal as the provider and pick the free Solar Mini 4 variant.
Why can't I see Solar Mini 4 in my Hermes model list?
Your model list is probably cached.
Refresh the model list in Hermes Desktop, or run hermes model --refresh to re-fetch every provider's live list.
What should I do if Solar Mini 4 gets rate limited?
Switch your profile to another free Nous Portal model such as Step 3.7 Flash, Ling 3.1 Flash or Nemotron.
Then switch back to Solar Mini 4 later when it's less busy.
Is Solar Mini 4 as good as Claude Opus 5.5 inside Hermes?
No, it isn't.
Solar Mini 4 is fast, free and fine for basic agentic tasks, but it's not frontier level and Claude Opus 5.5 is far stronger on hard work.
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About Julian
I'm Julian Goldie, an SEO entrepreneur, author and founder of the AI Profit Boardroom, which has 3,400+ members.
I help business owners scale with AI agents, automation and SEO.
- I've built a 7-figure agency, Goldie Agency, with a team of around 50 people.
- I've grown a YouTube channel to 400,000+ subscribers.
- I wrote the Amazon best-sellers "SEO Link Building Mastery" and "Agency Marketing Mastery".
- My Udemy courses have taught over 50,000 students.
→ Get my best AI training inside the AI Profit Boardroom
Make a fresh profile, pick the free variant and run the four tests, and you'll have your own free Solar Mini 4 Hermes setup running today.
