Jev in production › Agent tool and action selection

System One Browser Agent

Browser agent combines sub-150ms Jev reflex decisions with Stagehand automation and an LLM fallback for harder steps; architecture described, no benchmark reported yet (author).

Open on GitHub ↗

The source publishes no measured number.
Use
Agent tool and action selection
Industry
Developer tools
Form
Open-source tool
Stage
Announced
Plugs into
Stagehand
Listed
2026-09-25
Found via
github
Repository
adnanahmaddev/system-one-browser-agent
Stars
4
Forks
0
Last push
2026-09-24
Language
TypeScript
License
none stated

The README opens with

A high-speed, dual-process autonomous browser agent harness combining sub-150ms Jev reflex decisions with Stagehand stealth automation and Gemini/Claude System 2 reasoning.

Traditional browser agents query an autoregressive LLM for every single DOM interaction—burning 3–8 seconds and thousands of tokens per step just to decide simple clicks or verify whether a page is done loading.

Inspired by Daniel Kahneman’s Thinking, Fast and Slow, System One splits browser navigation into two complementary tiers:

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For the project's own README, linking back here:

Listed in Jev in production

Also used for agent tool and action selection