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How to filter Amazon products fast with Jev

An AI agent went through 20 Amazon listings and decided which ones fit. With Jev making the decisions it finished in under 4 seconds. A frontier model took almost a minute, and the answers were the same. Here’s the browser it ran in, how to install it, and a prompt that builds the filter for whatever you’re shopping for.

Written September 28, 2026 · By Ben Broch
product decisions
20
with Jev
3.71s
with GPT-5.6 Sol
54.45s

From @ego_agent’s public demo

Get the browser on GitHub ↗Let Claude Code / Codex build it ↘

The code: the browser is open source, the race isn’t

The demo is by ego, the team behind ego lite, a free Mac browser that your AI agent drives while you keep using yours. The browser is on GitHub. The script that ran the race isn’t published, and ego says it doesn’t have a Jev-specific integration yet. Jev works through the normal setup.

16.6k ★stars on GitHub, September 28
MITlicence: use it for anything
MacWindows in beta, Linux on the roadmap
NoJev code in the repo: you add it (prompt below)
Install ego lite
# From the ego lite README (I haven't run these myself)
# 1. Install the Mac app from https://lite.ego.app  (free)
#    It adds the ego-browser skill to every agent on your Mac.
# 2. Or install only the skill:
npx skills add citrolabs/ego-lite

Repo: github.com/citrolabs/ego-lite · Site: lite.ego.app

01

What the demo did

A split-screen race titled “JEV Speed Race: Filtering Amazon Products”. Both sides get the same job: go through earbud listings and decide which ones meet the brief. The Jev side locks in all of its answers at 3.71 seconds. The GPT-5.6 Sol side is still going at 54.45 seconds. Both score 10 out of 10.

One caveat: on screen the GPT side is labelled as playing at 2x, so the two halves aren’t recorded at the same speed. The timers are what they are, but it isn’t a clean side-by-side video.

02

Why it’s faster: the agent stops thinking out loud

A reasoning model writes an essay before every yes or no. Jev doesn’t write anything. It returns the probability of each answer. When the task is a pile of small judgments, like “does this listing fit?”, most of an agent’s time goes on that essay, and Jev skips it.

The same pattern with Jev

One call per listing:

Keep a listing only when every answer clears the bar. That’s how a person shops too: one dealbreaker is enough. It’s the same shape as the prospecting guide, with a listing in place of a post.

New to Jev? Start with the setup guide: key, first call, working response. Then come back.

Let an agent build it

Paste this at Claude Code or Codex once ego lite is installed. It shortlists and never buys. The 0.60 bar is a starting point I haven’t run yet.

Paste at Claude Code / Codex
Build me a product-filtering job using Jev through the Vercel AI Gateway, driving my browser with the ego-browser skill.

1. Ask me what I'm shopping for, in one plain sentence, plus my hard rules (for example: "wireless earbuds under $80, noise cancelling, at least 4 stars, not a no-name brand").
2. Open the Amazon search results in the browser and collect the first 20 listings: title, price, rating, number of reviews, whether it's sponsored, and the bullet points.
3. For every listing make ONE call: experimental_evaluate from the ai package, model typesafe-ai/jev. The state is the listing as plain text. Ask one boolean question per rule, all together in that one call, each written as a plain statement, for example:
   - fits: "This product is <what I'm shopping for>."
   - price: "The price is under $<my limit>."
   - trusted: "This is an established brand, not an unbranded or relabelled product."
   - reviews: "The rating and review count suggest real buyers are happy with it."
4. Keep a listing only if every answer is at least 0.60. Rank the keepers by the lowest of their scores, so one weak answer can't hide.
5. Run 3 calls at a time; bursts get rate-limited. Time the whole run and tell me how long Jev took.

Show me the shortlist with links and scores. Never add anything to the cart or buy anything. I choose and check out myself.

The honest part

I haven’t run this one. The numbers are from @ego_agent’s post, and ego calls its Jev demos “toy experiments”. The install steps are copied from the ego lite README. There’s no code here because I only publish code I’ve run.

Your agent will be using your logged-in browser. Keep it on the shortlist job, and check out yourself.

Don’t have Jev running yet?

The setup guide is one key and a few lines of code, and you’ll have a working response in a few minutes.

Get started with Jev →

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