operations / agent

Jev Ultrafast

A browser agent with an indexed action space: Jev picks an operation and a page element, and a small language model writes text when needed.

Repository owner browser-use

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Published 11 Oct 2026Listing updated 12 Oct 2026

At a glance

Purpose: A browser agent with an indexed action space: Jev picks an operation and a page element, and a small language model writes text when needed.
Runs in: Local agent with shell, Web service
Operating systems: Not stated
Needs: Runtime: uv and Chrome; Needs internet: Yes; Needs accounts or API keys beyond your agent: Not stated
Files and data: Reads files: Yes; Writes files: Yes; Sends data to other services: Not stated
Tool type: Agent
Delivery: From GitHub
Version: Latest on the main branch
Access: Code on GitHub
Compatibility: According to the README, it connects to Chrome through Browser Harness, which uv sync installs, and uses TypeSafe's Jev for its decisions. The README says the text helper uses an OpenRouter key in the example configuration and that Gemini, GLM and DeepSeek can also use the OpenAI-compatible text helper. The README does not name operating systems.
External costs: According to the README, setup needs a TypeSafe API key and a text-model API key. It says the text-model key is an OpenRouter key in the example configuration, that the demo uses the model inception/mercury-2.5 with reasoning disabled, and that Gemini, GLM and DeepSeek can also use the OpenAI-compatible text helper. It says live examples and recording scripts make paid API calls. It gives no prices. The repository is MIT-licensed. Your coding agent or model provider may charge for usage.
Permissions: The README's setup installs dependencies with uv sync, including Browser Harness, and requires a TypeSafe API key and a text-model API key. The README says to allow Chrome remote debugging when prompted. The README describes browser actions for clicking, typing, selecting and scrolling, and says owned tabs share the existing Chrome profile. The README says the flights example saves a trace and does not select or book a flight. The README says live examples and recording scripts make paid API calls. The top-level entries include scripts/; the README names guard-checking and recording/rendering scripts.
Usage terms: MIT License, as stated in the repository. See its LICENSE file for the exact terms.

Code on GitHub

browser-use/jev-ultrafast

MIT

Python22,748 stars1,675 forksLast pushed 30 Sept 2026 UTC

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Public GitHub data fetched 13 Oct 2026 UTC · 0 days old

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What it does

The README describes Jev Ultrafast as a browser agent with a dynamic, indexed action space. The README says TypeSafe's Jev selects an operation and element from observed page controls, while a small language model generates text for TYPE_TEXT.

The README lists CLICK, TYPE_TEXT, SELECT, SCROLL_UP, SCROLL_DOWN, WAIT, DONE and BLOCKED. The README says the default agent loop uses structured state rather than screenshots and describes page-freshness and target checks before execution.

The README shows a Python Agent class, a local inspector and example scripts for Google Flights and Wikipedia tasks. The README calls the implementation an MVP and lists excluded browser features.

Who it is for

Developers who want to run or study a browser agent that works from a numbered table of page controls.

Example tasks

Start the local inspector with uv run jev and run the demo automatically.
Use Choose next in the inspector to pause before each action executes.
Create an Agent with a start page and a goal, and read the status of each state it yields.
Run examples/run.py with a start page and a goal to try a different task.
Run examples/flights.py with --keep-open to search for flights without booking one.

Getting started

The README says to clone the repository and change into its folder, then run uv sync, copy the example environment file with cp .env.example .env, add TYPESAFE_API_KEY and TEXT_MODEL_API_KEY, and run uv run jev. Then open the local address on port 8766 and start the demo. The README says Chrome connects through Browser Harness, which uv sync installs. The README says to run uv run browser-harness --doctor if it needs connecting. The README has the exact commands.

Limitations

According to the README, setup needs a TypeSafe API key and a text-model API key, and you allow remote debugging in Chrome when prompted. The README calls the project an MVP. It says the DOM reader handles common HTML and ARIA controls, not the full accessible-name specification, and that shadow roots, frames, canvas, uploads, pop-up tabs, nested scrolling and arbitrary keyboard widgets remain outside it. It says owned tabs share the existing Chrome profile, that after a DONE choice an independent check of the outcome is still required, and that its timing results are three repeats of one task on one browser profile, not a general reliability benchmark. It says live examples and recording scripts make paid API calls. The repository can change at any time; check its README before you install.

Data practices

According to the README, each decision cycle makes one TypeSafe request that uses the observed element table, and a small language model writes the text for TYPE_TEXT. The README says the default agent loop consumes structured state without screenshots and that the inspector opts into screenshots. The README says it sends visible text, and that offscreen article bodies and footers do not fill the model context. It says credentials and raw traces stay ignored. The README does not mention telemetry.