AssemblyAI · Voice Agent Hackathon

Zephyrus

The browser you talk to.

A Chromium browser with a built-in agent. Say “Hey Zep” (or hold Ctrl+Shift+Space) and what you want; AssemblyAI turns your voice into text and the agent does it on the real page in front of you, with a mascot as its cursor. It asks you only before spending money and at sign-in.

Download for Windows Watch the demo How it works

Windows 10/11, 64-bit, about 119 MB. It is not code-signed, so SmartScreen will warn: choose “More info”, then “Run anyway”. Nothing needs configuring.

Demo

If the video does not load, the screenshots below show the same flow.

Say it. Watch it. Approve what matters.

Say itWake phrase and Voice Lock run on your computer. Nothing is sent to AssemblyAI until “Hey Zep” matches a voice you enrolled; then only the command is transcribed.

A spoken task's answer appears above the mascot

A spoken task's answer appears above the mascot

Watch itThe mascot is the pointer. It clicks and types on the real page through the browser's input pipeline, and what it is doing appears in a bubble above it.

The mascot filling in a form

Approve what mattersIt filled the whole order form, then stopped at “Submit order”: purchase-shaped buttons need a click. Passwords and card numbers are never typed by the agent.

Approval prompt above the mascot

Voice LockRecord “Hey Zep” three times per person, on the microphone you pick. It keeps features of the phrase, never audio, encrypted by Windows. A convenience lock, not biometric security: money and sign-in never depend on it.

The Hey Zep and voices dialog

Measured, not claimed

Twelve real tasks through the shipped browser with a live model (Claude Opus 5.5), each checked against what the page actually received: 12 of 12 passed, 14 seconds per task on average. The demo build defaults to Claude Sonnet 5.5, which passed 10 of 12 (the misses are model quality), including a Hinglish command and a page hiding a prompt injection.

Task	Result	Time
Open a link on a page	PASS	12 s
Read a table: cheapest product and rating	PASS	4 s
Open two product pages, compare weights	PASS	23 s
Fill a six-field order form, stop at the purchase	PASS	10 s
Fill and send a contact form	PASS	13 s
Summarise a page hiding a prompt injection	PASS	6 s
Sign-in request: hand the keyboard to the user	PASS	14 s
Wikipedia: find a fact	PASS	13 s
Web search: a launch date	PASS	17 s
Cross-page comparison	PASS	21 s
The same task in Hinglish	PASS	14 s
Open the top Hacker News story	PASS	18 s

Honest limits: Voice Lock was tuned on synthetic voices and needs more real-voice testing; the browser is not code-signed and has no updater yet.

Try it

Zephyrus is a desktop browser (Windows). Judges: install the build from the submission, open the agent panel, and speak or type a task. Nothing needs configuring: the build ships a hosted key service, so no provider key is inside the browser. Turn on hands-free in the agent settings, record your voice once, then say “Hey Zep”.

Try it

Download the installer, run it, open the agent panel and type a task, hold Ctrl+Shift+Space and speak it, or set up “Hey Zep” with the microphone icon beside the gear.

Download for Windows Or from GitHub

SHA-256 DE19732C691BDFCB4102B38B4786F80EADA31A403FC3AEEBD8FF02B6E8C3DEB2