DEMO / RECORDING
Overview & Result
Sac created 'Jev Use', combining Codex with TypeSafe's Jev model for desktop computer use on macOS. In a side-by-side benchmark creating Mac Calendar events, Jev handles UI element selection and click targeting in single-digit milliseconds while reserving heavy models only for text input, resulting in an estimated 10x speedup with near-zero pauses and identical token consumption.
How Jev fits in the loop
- Codex reads the macOS screen state and accessibility element hierarchy.
- Jev selects the target calendar field or button in single-digit milliseconds.
- Codex executes the click immediately and invokes generative completion only when entering freeform text.
How to reproduce
- Clone Codex CLI computer use harness on macOS with Accessibility permissions enabled.
- Configure Jev as the decision layer to predict UI element coordinates from the system accessibility tree.
- Run benchmark: Add Calendar event 'Meeting with Alex' at 3pm Friday, comparing native Codex vs Jev Use.
Why this build matters
Demonstrates that desktop computer use latency can be solved by decoupling fast System One UI action choices from slow generative LLM reasoning.
Limitations
- Requires macOS Accessibility API permissions.
- Non-native web canvases without accessibility nodes require visual OCR fallback.