Back
browseragentsdeveloper-toolsOpen source

Cua Driver jev-use

A public-preview Cua Driver recipe for bounded Jev browser actions with independent verification.

What Jev decides

Which supplied action candidate to take next, or whether to reobserve or abstain.

Equivalent Python and TypeScript loops observe through Cua Driver, construct immutable snapshot-bound candidates, let Jev select one ID, validate it, execute through Driver, and verify the fixture state separately.

CHOICE
Jev role
Choose one immutable browser action candidate while Cua Driver owns observation, execution, permissions, and verification.
Input
The task goal, compact current observation, capture identity when applicable, bounded history, and at most 32 candidate IDs with descriptions.
Output
One allowlisted candidate ID, confidence, and the probability distribution over candidates.
Decision frequency
Once per step in the bounded browser decision loop.
Fallback
Reobserve or abstain, reject stale and malformed candidates, and never retry an uncertain action blindly; verify success through independent fixture state.
Author reported · Source reviewed

How it works

Input
The task goal, compact current observation, capture identity when applicable, bounded history, and at most 32 candidate IDs with descriptions.
Jev
CHOICE
Output
One allowlisted candidate ID, confidence, and the probability distribution over candidates.

Overview

Cua Driver jev-use is a public-preview example inside the Cua repository rather than a standalone product. It keeps TypeSafe-specific provider code above the driver and demonstrates a narrow decide-act-verify boundary in both Python and TypeScript.

Candidates are built from fresh browser semantics or validated visual regions and always include reobserve and abstain. Jev sees compact observations and allowlisted IDs, not screenshot bytes or executable tool arguments. The credential-free mock proves the Driver lifecycle, action loop, stale-reference handling, and postcondition checker; live Jev verification is optional and must be recorded separately.

Language
Python / TypeScript
License
MIT
Author
Cua contributors
Sources checked Sep 21, 2026

Sources

Related projects