01What Is OpenCode Cat Jam and How It Works
OpenCode Cat Jam is a new stealth model inside OpenCode. It is designed to be very fast, built for agentic coding, and offers zero data retention for privacy. Julian Goldie explains that this model is free for a limited time but with unlimited use.
It was released just yesterday, so there is not much information about it yet. The exact creator and underlying model remain unconfirmed, but some people suggest it might be a Quen or Gemini variant.
Cat Jam is a stealth model, meaning its details are hidden. However, unlike many stealth models, this one does not use your data for model training. The provider retains data for up to 30 days for safety reasons only.
This makes it a good choice if you care about privacy while building quickly. It is not available in some countries, but for most regions it is accessible.
02Key Features of OpenCode Cat Jam
Cat Jam has several important features. First, it is built specifically for agentic coding, which means it can help AI agents write code quickly. Second, it has fast generation speeds—it can build a to-do list app in just 10 seconds.
Third, it offers data privacy with zero data retention from the provider. This is unusual for a free stealth model.
- Free for a limited time with unlimited usage.
- Performance optimized for agentic coding tasks.
- Zero data retention: your data is not used for model training.
- Fast response times: much faster than other free models like Big Pickle.
- Can be used inside Hermes Agent or an agentic operating system.
- You can switch to other free models if you get rate-limited.
03How to Set Up OpenCode Cat Jam
Getting started with OpenCode Cat Jam is simple. Follow these steps to use it for free.
- Go to OpenCode on your browser or inside your agentic operating system.
- Look for the list of free models on the OpenCode interface.
- Select Cat Jam from the available free models. It may appear as a new stealth model.
- If you are inside an agentic OS, you can plug Cat Jam into your workflow directly.
- Start a conversation or give it a task, like building a to-do list app.
- If you get rate-limited, switch to another free model like Long Cat 2.5 or Step Five Preview.
Cat Jam works immediately once selected. Julian shows that you can simply type "Are you working?" and the model responds right away.
04How to Use OpenCode Cat Jam for Agentic Coding
To use OpenCode Cat Jam, you can give it coding tasks and see results in seconds. In the episode, Julian tests it by asking it to build a beautiful to-do list app. The model builds the app in about 10 seconds, which is very fast.
He compares this to older local models that used to take 30 minutes for similar tasks.
Cat Jam works well inside an agentic operating system. You can have it run as a sub-agent to handle quick coding jobs. For example, you can use it inside Hermes Agent for custom workflows like a pop-up voice agent or content idea generator.
The results appear in your workspace, where you can preview everything you have built. This makes it easy to track projects over time, unlike using OpenCode directly where it can be hard to find past work.
05Results and Comparisons Shown in the Episode
Julian shows a side-by-side test of Cat Jam and Big Pickle. Adam Roman gave both models the same prompt. Cat Jam finished the task in half the time, but Big Pickle was preferred on the UI.
However, Cat Jam is more than twice as fast for building code. Julian says Cat Jam is nowhere near Opus 5.5 level, but it is a good choice for fast, agentic coding.
He also compares Cat Jam to other free models like Long Cat 2.5 and Step Five Preview. He tested Step Five Preview personally and found it very fast but not as good as Opus 5.5. Cat Jam is faster than these models for simple tasks.
The speed improvement is significant: building a to-do list app in 10 seconds is something Julian had never seen before. The agentic OS also helps keep track of all projects visually, which is a big advantage over using OpenCode alone.
06Tips, Limits and Mistakes to Avoid with Cat Jam
When using OpenCode Cat Jam, keep these tips in mind. First, it is not as powerful as top models like Opus 5.5, so do not expect the same quality for complex tasks. Second, it is a new stealth model with limited information, so you may not know its exact capabilities or creator.
Third, it is not available in all countries—check the list before relying on it.
If you get rate-limited, switch to another free model like MIMO V216 or Muse Spark. Do not depend on Cat Jam for critical work if you are in a restricted region. Also, remember that while data is not used for training, it is retained for 30 days for safety.
If you need absolute privacy, consider other tools. Julian advises using Cat Jam mainly for fast sub-agents or quick builds, not for final production apps.
07Who Should Use OpenCode Cat Jam and Why
OpenCode Cat Jam is for anyone who needs a fast, free model for agentic coding. If you build AI agents that need to write code quickly, this model can help. It is great for sub-agents that perform small, rapid tasks.
Julian mentions that inside his agentic OS, Cat Jam works well for quick builds like a to-do list app.
This model matters because it offers speed and privacy without cost. It is free for a limited time, so you can try it without risk. It also does not use your data for training, which is rare for a free model.
If you are a developer or AI agent creator who values fast iteration, Cat Jam is a good tool to add to your workflow. It is not a replacement for powerful models, but it fills a niche for speed.
