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For a long time, we've been used to interacting with AI as if it were a dialogue. You write a query, the model answers. If you want to do something — like analyze data or write code — you have to break the process down into dozens of small steps and copy-paste everything yourself. With the arrival of Agent Mode from Arena.ai, this model is changing. AI is no longer just a "speaker" — it's becoming a "worker."
What exactly is Agentic AI and how does Agent Mode work?
The term Agentic AI refers to systems that have the ability to autonomously plan. While a typical model like GPT-4 or Claude 3.5 focuses on predicting the next word, an agentic system receives a goal (for example: "Find the best watches under 5,000 CZK, compare them, and create a comparison table in Excel") and plans its own steps to achieve it.
As part of its new announcement on X, Arena stated that Agent Mode uses several key tools:
- Web search: The agent verifies current information in real time on its own.
- Bash in a sandbox: This is the most technically important element. A "sandbox" is an isolated, secured environment where the AI can run commands, install libraries, and test code without threatening your computer or system.
- File handling: The model can not only read but also create and edit documents.
- Image generation: Integration of visual models directly into the workflow.
Comparison of top models in agent mode
Arena is unique in that it doesn't sell you a single proprietary model — it lets you test the world's best "frontier" models within a single agent interface. According to current information, you can switch between these giants in Agent Mode:
| Model | Strengths in agent mode | Competition (e.g., OpenAI Operator) |
|---|---|---|
| GPT-5.5 | Extreme logic and planning of complex tasks. | Leader in logical reasoning, but often locked into the OpenAI ecosystem. |
| Claude Opus 4.7 | Best for writing code and nuance in text. | Anthropic focuses on safety, which is crucial in a sandbox. |
| Gemini 3.1 Pro | Huge context window (suitable for analyzing entire books). | Google has the advantage of integration with Google Workspace. |
Practical impact: What does this mean for you?
For the average user, this means AI is no longer a toy for creative writing — it becomes a productivity tool. Instead of searching for information on Wikipedia or Google, you can say: "Do in-depth research on the electric vehicle market in the Czech Republic over the past year and prepare a presentation for me."
For businesses and developers: The ability to use a bash sandbox means a programmer can delegate debugging or test script writing to an agent. The agent writes the code, runs it, sees the error, fixes it, and only then hands you the finished result. This dramatically shortens the time required for software development.
Availability in the Czech Republic and language support
Although Arena is primarily a global platform, its tools are available to users in the Czech Republic through its web interface. A key question is the Czech language. Most top models (GPT-5.5, Claude) handle Czech at a very high level. However, for agent tasks such as writing code or working in a terminal (bash), English is still the operational language. For a Czech user, this means that instructions can be given in Czech, but the result in the technical part will likely be in English.
From the perspective of EU regulation (AI Act), the aspect of transparency is important here. Because Agent Mode performs autonomous actions, systems like Arena must meet strict requirements to make it clear what the agent did and why. The sandbox environment is, in this respect, an ideal safeguard against unintended data damage.
Pricing and how to get started
Arena is generally not worthwhile as a cheap tool for everyday chatting, but rather as a professional platform. According to available information, it offers:
- Free tier: Limited access to model testing (without full Agent Mode).
- Subscription (Pro/Premium): Estimated at around $20–30 per month (approximately 450–700 CZK). This price gives you access to the most expensive models like Claude Opus or GPT-5.5, which would cost much more with individual providers.
If you're looking for a tool that will "do the work" for you, not just "write text," Arena Agent Mode is currently the best laboratory where you can put these capabilities to the test side by side.
Is it safe to let AI run commands in a terminal (bash)?
Yes, because Arena uses what's called a sandbox. This is an isolated virtual environment that is not connected to your operating system or personal files. If the AI makes a mistake or runs a harmful command, the damage remains confined to this closed "box."
Can Agent Mode work directly with my local files on my computer?
Not directly. For security reasons, you must first upload files to the Arena platform. The agent can then work with these uploaded files, analyze them, and create new versions.
How can I tell whether the agent is working correctly and not hallucinating?
Arena allows you to observe the agent's "thought process" (reasoning trace). You can see the individual steps it planned, the results of its web searches, and the terminal outputs. This gives you the ability to intervene or stop the process at any step.
