# Agent S review

> Agent S is an open-source computer use agent framework from Simular that completes plain-English tasks by clicking, typing, and scrolling in desktop apps.

Devtoolwatch Board, the week of Oct 25–31, 2026. Canonical page: https://index.devtoolwatch.com/tools/agent-s/

## TL;DR

Agent S is an open-source Python framework from Simular for building computer use agents. An agent takes a task in plain English, looks at the screen, and operates ordinary desktop and web apps on macOS, Windows, and Linux. It ships as the gui-agents library, and its versions are backed by published research papers.

## Agent S at a glance

- **Category:** [Browser and computer use](https://index.devtoolwatch.com/categories/browser-and-computer-use/)
- **Maintained by:** Simular (organization, [@simular-ai](https://github.com/simular-ai) on GitHub)
- **License:** Apache 2.0
- **Language:** Python, Shell, JavaScript
- **Repository:** [github.com/simular-ai/Agent-S](https://github.com/simular-ai/Agent-S)
- **Website:** [www.simular.ai](https://www.simular.ai)
- **PyPI package:** [gui-agents](https://pypi.org/project/gui-agents/) 0.3.2
- **Latest release:** [v0.3.2](https://github.com/simular-ai/Agent-S/releases/tag/v0.3.2) on GitHub, Dec 16, 2025
- **First published:** Oct 9, 2024

## What Agent S does

- Agent S takes a task in plain English and completes it by clicking, typing, and scrolling in desktop and web apps.
- Agent S looks at the screen to decide its actions, operating a real GUI the way a person would.
- Agent S runs on macOS, Windows, and Linux.
- Agent S provides the gui-agents library for creating general purpose GUI agents using multimodal LLMs.
- Agent S4 evolves the tool interfaces a computer use agent works through, based on its own task experience.
- Agent S includes a Ctrl+C signal handler that pauses the agent for debugging.
- Agent S has added support for model providers such as Gemini and OpenRouter.

## How to install Agent S

**From PyPI**

```
pip install gui-agents
```

### Requirements

- Python 3.9 to 3.12 for the gui-agents package.
- macOS, Windows, or Linux.
- A Simular API key if you use the cloud option.

### First steps

1. Follow the Agent S3 README in the repository to run Agent S on your own computer.
2. To avoid local setup, run Sai on a cloud computer through the Simular API, which requires an API key.

## Who Agent S is for

- Developers building agents that operate desktop and web apps through the GUI.
- Researchers studying computer use agents and benchmarks like OSWorld.
- Python developers building GUI agents on multimodal LLMs.

### Limitations

- Agent S's gui-agents package supports Python only up to version 3.12.
- Agent S requires local setup to run on your own machine; the no-setup path uses Simular's hosted API instead.
- Agent S's OSWorld V2 score is a strict pass/fail measure, so many hard tasks still fail.

## Usage data (the week of Oct 25–31, 2026)

- Board rank: #209 overall, #8 in Browser and computer use, momentum score 43
- Downloads that week: 349 (−18% vs 4-week average)
- New GitHub stars per week (last 12 weeks): Aug 9: 31; Aug 16: 28; Aug 23: 25; Aug 30: 33; Sep 6: 53; Sep 13: 53; Sep 20: 63; Sep 27: 148; Oct 4: 59; Oct 11: 71; Oct 18: 89; Oct 25: 122

## Agent S alternatives

| Rank | Tool | Stars | Downloads/wk |
|---|---|---|---|
| #1 | [ego lite](https://index.devtoolwatch.com/tools/citrolabs-ego-lite/) | 21k | – |
| #2 | [Moli](https://index.devtoolwatch.com/tools/lexmount-moli/) | 21.9k | – |
| #3 | [Cua](https://index.devtoolwatch.com/tools/cua/) | 31.4k | – |
| #4 | [Browser Harness](https://index.devtoolwatch.com/tools/browser-use-browser-harness/) | 18.8k | 3.3M |
| #5 | [Jev Ultrafast](https://index.devtoolwatch.com/tools/browser-use-jev-ultrafast/) | 24k | – |
| #6 | [Stagehand](https://index.devtoolwatch.com/tools/stagehand/) | 25.9k | 3M |

## Agent S FAQ

### Is Agent S free and open source?

Yes. Agent S's source code is on GitHub (simular-ai/Agent-S) under the Apache 2.0 license, so you can use it for free.

### How do I install Agent S?

Run `pip install gui-agents`. The gui-agents package needs Python 3.9 or newer.

### Is Agent S still maintained?

Yes. The simular-ai/Agent-S repository was last updated on Oct 24, 2026, and the latest release, v0.3.2 on GitHub, came out on Dec 16, 2025.

### How popular is Agent S?

Agent S has 12.8k GitHub stars as of Nov 1, 2026. It gained 122 new stars in the week of Oct 25–31, 2026, against a 12-week average of 65 a week. Its main package had 349 downloads that week, −18% against its own 4-week average. That made it #8 among browser and computer-use agents on the Devtoolwatch Board.

### What are the best alternatives to Agent S?

Other browser and computer-use agents on the Devtoolwatch Board in the week of Oct 25–31, 2026, by momentum: ego lite (#1), Moli (#2), Cua (#3), Browser Harness (#4), Jev Ultrafast (#5). The alternatives table above has their numbers.

### What does Agent S do?

Agent S is a computer use agent framework. You give it a task in plain English. It looks at the screen and completes the task by clicking, typing, and scrolling in ordinary desktop and web apps.

### Which operating systems does Agent S support?

Agent S runs on macOS, Windows, and Linux. Linux and Windows support was added in gui-agents v0.1.2.

### What is the difference between Agent S3 and Agent S4?

Agent S3 is the agent shipped in gui-agents today. Agent S4 is a newer version that evolves the tool interfaces its agents work through, based on task experience. Each version has its own README in the repository.

### Can I use Agent S without installing anything?

Agent S itself runs locally. For a no-setup option, Simular's production agent Sai runs on a cloud computer through the Simular API.

### How do I pause Agent S while it is running?

Agent S includes a Ctrl+C signal handler that pauses the agent for debugging. It was added in v0.3.0.

## Sources

1. [simular-ai/Agent-S on GitHub](https://github.com/simular-ai/Agent-S)
2. [Agent S README](https://github.com/simular-ai/Agent-S/blob/main/README.md)
3. [gui-agents on PyPI](https://pypi.org/project/gui-agents/)
4. [Agent S website](https://www.simular.ai)
5. [Release v0.3.2 (Dec 16, 2025)](https://github.com/simular-ai/Agent-S/releases/tag/v0.3.2)
6. [Release v0.3.1 (Oct 4, 2025)](https://github.com/simular-ai/Agent-S/releases/tag/v0.3.1)
7. [Release v0.3.0 (Oct 3, 2025)](https://github.com/simular-ai/Agent-S/releases/tag/v0.3.0)
8. [Devtoolwatch Board, the week of Oct 25–31, 2026](https://index.devtoolwatch.com/)