Jev Ultrafast

Overview

Jev Ultrafast is a browser agent with a dynamic, indexed action space from Browser Use and TypeSafe. It takes one natural-language goal, reads an element table from the page, selects an operation and target, and calls a small LLM for text only when the operation is TYPE_TEXT.

Key Features

• Dynamic indexed action space with the operations CLICK, TYPE_TEXT, SELECT, SCROLL_UP, SCROLL_DOWN, WAIT, DONE, and BLOCKED.
• One TypeSafe request per decision cycle for operation and target selection.
• No screenshots in the default agent loop; the agent consumes structured page state.
• Atomic DOM snapshot with indexed controls, freshness guards, and target validation.
• A small LLM generates text only when the operation is TYPE_TEXT.
• Local inspector shows numbered elements, operation probabilities, target probabilities, and executed actions.

Use Cases

• Search Google Flights for one-way Zurich to London flights on September 20, 2026 for one adult in economy.
• Find and open the Wikipedia article about Gödel’s incompleteness theorems.
• Run a local hotel search and filter task.
• Inspect operation probabilities, target probabilities, and executed actions in a local inspector.

Getting Started

• Clone the repository and run uv sync.
• Copy .env.example to .env and add TYPESAFE_API_KEY and TEXT_MODEL_API_KEY.
• Run uv run jev.
• Open the local inspector on port 8766, then click Start demo and Run automatically.
• Use Choose next to pause before execution.

Deployment & Requirements

• Python environment managed with uv.
• TYPESAFE_API_KEY and TEXT_MODEL_API_KEY.
• Chrome connected through Browser Harness, which uv sync installs.
• Allow remote debugging in Chrome when prompted.
• The example configuration uses an OpenRouter key for TEXT_MODEL_API_KEY.

Before You Adopt

• License: MIT. Review its terms before using, modifying, or distributing the project.
• The current release is an MVP with several browser features outside its scope.
• The DOM reader covers common controls but not the full accessible-name specification.
• Some examples and recording workflows incur paid API usage.
• Browser tabs used by the agent share the existing Chrome profile.
• Reported timing results come from a narrow repeated test rather than a general reliability benchmark.