A strong free agent, at the lowest cost that still works
This guide shows you how to run a strong, free, open-source agent that can use a computer for you. It is written for someone on Windows 11 or a Mac.
If a word is unfamiliar, look it up in the glossary, which defines each term once. On the website, you can also hover over an underlined term to see its definition.
The pick
This guide picks Agent Zero, which came first on a scorecard (a scored comparison) with 70. Atomic Agent scored 68.5 and Hermes Agent scored 68, so the lead is small.
Agent Zero works inside a Linux container on your computer. That container starts with its own files, so the agent does not start out on your real ones.
What a normal month can cost
The agent is free, but the model it uses can cost money. These rows are the common choices, from free to paid, and the full table, with the catches, is in Pick your model and budget.
| Option | What you pay in a normal month |
|---|---|
| Google Gemini, free | $0, within a daily limit Google sets for you |
| Z.AI GLM-4.7-Flash | $0, with a limit Z.AI does not publish |
| Groq free plan (Qwen3.8-27B) | $0, but only about 3 jobs a day fit in the free cap |
| OpenRouter's free models | $0, up to 50 requests a day, or 1,000 a day for good after a one-time $10 credit purchase |
| Local, on a computer you already own | $0 plus the computer you already own |
| DeepSeek's cheap model on its own | about $4, or about $9 in its pricier hours |
| Light hybrid (a cheap model for ordinary steps, and a stronger model for the hard parts) | about $17 |
| Ollama's cloud plan (Pro) | $20, which includes $60 of cloud use |
| A ChatGPT plan you already pay for, signed in under OpenAI's rules | Your plan's price ($8 for Go or $20 for Plus), up to its limit |
| A mid-size model from OpenAI, Google, or Claude, pay as you go | about $34 to $67 |
| The strongest model from Claude or OpenAI for every step | about $134 to $336 |
Each $0 cloud row has a catch, such as a daily limit that can stop a long job halfway, or a company that may use your prompts. Free options and their limits lists each limit. The paid amounts assume a light month of about 160 agent steps a day.
Start here
Read these in order, because each page picks up where the last one left off.
- Pick your model and budget
- Your first 10 minutes
- Files, the browser, and memory
- Your phone and scheduled jobs
- Ten jobs to try
- Fixes and other agents
- Safety versus capability
- Advanced Agent Zero
- Persona and rules
If Agent Zero does not fit, other agents has a full eight-page guide for each of the nine others this guide looked at.
Seven pages apply to every agent. They start with how to choose a model for your job and how to reach strong models for less, then cover running a free local model with Ollama, prompting strong and weak models, and adding skills and MCP tools safely. They also cover setting a persona and rules and cleaning up after it does something wrong.
Once the basics work, the Advanced section covers setups that apply to any agent. Topics include local models, mixing models, host access, an always-on machine, subscription sign-ins, relays, and uncensored models. Each page states its risks plainly.
Everything here was checked on 15 November 2026, and prices and limits change.