trenchcoat
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Website report · 4 h ago

just-four.fun

“justfor.fun — trade predictions on anything”

Template-written 25 evidence items Code reader analysed 12 scripts
What this means for you

just-four.fun talked to 2 outside services on a first visit.E5E4

  • An AI agent used the site and saw 1 of 3 claimed features working.E21E22E25E21E22E24
  • Staking / yield: “…ETH ETF staking approved? 55% chance Buy Yes Buy No $540.0K Vol. …”: The quoted text is a prediction-market card titled 'ETH ETF staking approved?', not a staking or yield feature. Nowhere on the site did I find a way to stake or earn yield. The card is there, and a search for 'staking' brings it up, but clicking 'Buy Yes' was blocked because it is a trade.E21E22E25
  • Extra observation: market data loads from a backend: Reloading the homepage made calls to a Supabase backend for markets, leaderboard and callouts. The percentages and volumes on the cards changed a little between loads (ETH ETF staking showed 56%, then 57%, then 55%). The leaderboard and callouts sections said 'No traders yet' and 'No callouts yet', even though the scrolling ticker shows usernames with profit figures.E21E22E24
  • Extra observation: Docs page: Going to /docs gave a 404 'Page not found' page.E23
  • Tech check: the site mentions staking / yield, but we found nothing behind it in what its public page loads.E19
  • We saw no known analytics or advertising services load on the first visit.E1
  • 2 cookies were set in your browser, all by the site itself.E6E7

Tech check

What the site says about itself, next to what its public page actually loads. Facts only, no verdict: you decide.

Nothing found on the public page

Staking / yield

“…Buy Yes Buy No $214.4K Vol. · ends Mar 31 3.1% ETH ETF staking approved? 55% chance Buy Yes Buy No $540.0K Vol. · end…”E19

No matching code, calls or services in what loaded for us.

Calls its own backend /__l5e/trackeventsE14
Wallet code PhantomE10E18E17
Contract calls in its code none seen
Talks to AI services none seen
Live connections none seen

What the AI agent tried

An AI agent (claude-opus-5-5) used the site in our sandbox for 5 steps and saw 1 of 3 claimed features working. It can't connect a wallet, pay, sign or log in, so those features count as "couldn't test". What it reports is what it observed, not a verdict.

Couldn't test

Staking / yield: “…ETH ETF staking approved? 55% chance Buy Yes Buy No $540.0K Vol. …”

The quoted text is a prediction-market card titled 'ETH ETF staking approved?', not a staking or yield feature. Nowhere on the site did I find a way to stake or earn yield. The card is there, and a search for 'staking' brings it up, but clicking 'Buy Yes' was blocked because it is a trade.E21E22E25

Seen working

Extra observation: market data loads from a backend

Reloading the homepage made calls to a Supabase backend for markets, leaderboard and callouts. The percentages and volumes on the cards changed a little between loads (ETH ETF staking showed 56%, then 57%, then 55%). The leaderboard and callouts sections said 'No traders yet' and 'No callouts yet', even though the scrolling ticker shows usernames with profit figures.E21E22E24

Not seen working

Extra observation: Docs page

Going to /docs gave a 404 'Page not found' page.E23

What it is

  • The Internet Archive has never saved this site, so it is probably new.E20
  • The site describes itself as: “Bet YES or NO on crypto, sports, politics and memes. Live trending markets, callouts and trader leaderboard.”E2
  • It's built with React (common tools for building web apps).E8
  • Notable building blocks in its code: Supabase client.E9
  • In your browser it can copy text to your clipboard and saves small bits of data in your browser.E11E12
  • While loading, it called 1 endpoint on its own servers, such as /__l5e/trackevents.E14

Where your data goes

Backend & data servicesDatabases, search and APIs the app runs on. 1
jtpiotwlzpruehtmxnno.supabase.coSupabase: app database and API 5×E5
FontsDownload typefaces. 1
fonts.googleapis.comGoogle Fonts: fonts 1×E4

Crypto and wallets

  • Wallet tools in the code: Phantom.E10
  • personal_sign: asks you to sign a text message (often to log in; moves no funds by itself).E18
  • eth_requestAccounts: asks to connect your wallet, which shows the site your address.E17

How key features work

Connecting your wallet

It connects to crypto wallets using Phantom, personal_sign and eth_requestAccounts. Connecting shows the site your wallet address; it doesn't move funds by itself.E10E17

Phantompersonal_signeth_requestAccounts

Live updates

It keeps live connections open (jtpiotwlzpruehtmxnno.supabase.co) so content updates without reloading.E5

jtpiotwlzpruehtmxnno.supabase.co

Loading its content

Its content loads from its own API while you browse (/__l5e/trackevents).E14

/__l5e/trackevents

Saving data on your device

It saves data in your browser (localStorage), so some things persist between visits.E12

local_storage

Cookies and storage

Names only. We never store the values.

CookieSet forKeptWhose
__dplE6just-four.fun about 1 daysthe site
__cf_bmE7just-four.fun about 0 daysthe site

Pages and API calls

Pages it links to

/

Endpoints

Called while loading (seen) or named in the code (code).

just-four.fun/__l5e/trackeventsseenE14
/api/broadcastcodeE15

Evidence

Every sentence above points to one of these. Code references show the file, line:column and the short identifier that matched, never the site's code itself.

E1
Page title: justfor.fun — trade predictions on anything
page title · https://just-four.fun/
E2
Page description: Bet YES or NO on crypto, sports, politics and memes. Live trending markets, callouts and trader leaderboard.
page description · https://just-four.fun/
E3
21 request(s) to just-four.fun
types: 9 image, 9 script, 1 document
GET https://just-four.fun/ · image · 21 requests · network recording
E4
1 request(s) to fonts.googleapis.com
types: 1 stylesheet
GET https://fonts.googleapis.com/css2 · stylesheet · network recording
E5
5 request(s) to jtpiotwlzpruehtmxnno.supabase.co
types: 4 fetch, 1 websocket
GET https://jtpiotwlzpruehtmxnno.supabase.co/rest/v1/profiles · fetch · 5 requests · network recording
E6
Cookie '__dpl' set for just-four.fun
kept for about 1 days
cookie __dpl on just-four.fun · value not stored
E7
Cookie '__cf_bm' set for just-four.fun
kept for about 0 days
cookie __cf_bm on just-four.fun · value not stored
E8
React detected by The code reader (react-runtime)
confidence: medium
just-four.fun/assets/index-BLZVUZKL.js · “react-runtime” · The code reader analyze-web-bundle 6.4.0
E9
Supabase client found in the code
just-four.fun/assets/social-DpgphCQc.js @ 3:35597 · “supabase-js” · pattern scan
E10
Phantom found in the code
just-four.fun/assets/coins-CFjZHQnC.js @ 1:20377 · “phantom.app” · pattern scan
E11
Uses the browser ability: clipboard_write
can copy text to your clipboard
just-four.fun/assets/routes-ByhiX2Kd.js @ 1:17270 · “clipboard.writeText(” · pattern scan
E12
Uses the browser ability: local_storage
saves small bits of data in your browser
just-four.fun/assets/coins-CFjZHQnC.js @ 1:22014 · “localStorage.setItem(” · pattern scan
E13
Uses the browser ability: web_worker
runs work in a background thread
just-four.fun/assets/social-DpgphCQc.js @ 9:6124 · “new Worker(” · pattern scan
E14
The page called /__l5e/trackevents on just-four.fun (POST)
POST https://just-four.fun/__l5e/trackevents · fetch · network recording
E15
The code names the endpoint /api/broadcast
just-four.fun/assets/social-DpgphCQc.js @ 3:62972 · “/api/broadcast” · pattern scan
E16
1 links to pages on the same site
page links · https://just-four.fun/ · /
E17
Wallet request in code: eth_requestAccounts
asks to connect your wallet, which shows the site your address
just-four.fun/assets/social-DpgphCQc.js @ 12:23296 · “eth_requestAccounts” · pattern scan
E18
Wallet request in code: personal_sign
asks you to sign a text message (often to log in; moves no funds by itself)
just-four.fun/assets/social-DpgphCQc.js @ 12:24017 · “personal_sign” · pattern scan
E19
The site says: “…Buy Yes Buy No $214.4K Vol. · ends Mar 31 3.1% ETH ETF staking approved? 55% chance Buy Yes Buy No $540.0K Vol. · end…”
page text · https://just-four.fun/ · …Buy Yes Buy No $214.4K Vol. · ends Mar 31 3.1% ETH ETF staking approved? 55% chance Buy Yes Buy No $540.0K Vol. · end…
E20
The Internet Archive has no saved copy of just-four.fun
page web archive · https://web.archive.org/web/*/just-four.fun
E21
Agent step 1: view
AI agent step 1 · view on /
E22
Agent step 2: type Search markets... ← “staking”
AI agent step 2 · type on / · page called POST just-four.fun/__l5e/trackevents
E23
Agent step 3: go /docs
AI agent step 3 · go on /docs · page called POST just-four.fun/__l5e/trackevents, GET jtpiotwlzpruehtmxnno.supabase.co/rest/v1/profiles
E24
Agent step 4: go /
AI agent step 4 · go on / · page called GET jtpiotwlzpruehtmxnno.supabase.co/rest/v1/profiles, GET jtpiotwlzpruehtmxnno.supabase.co/rest/v1/callouts, GET jtpiotwlzpruehtmxnno.supabase.co/rest/v1/leaderboard, GET jtpiotwlzpruehtmxnno.supabase.co/rest/v1/markets, POST just-four.fun/__l5e/trackevents
E25
Agent step 5: click Buy Yes (not done: Blocked: actions that pay, sign, trade or send are not allowed here.)
AI agent step 5 · click on /

Limits

  • We only see what your browser sees: code and requests on a first visit, without logging in or accepting cookie banners. What the servers do with data is invisible from outside.
  • Site code is usually minified (compressed), so names are partly lost and some code may be only partly analysed.
  • Some trackers only load after you accept cookies or log in, so the real list can be longer.
  • We visited from a server in the United States. Sites load different trackers and cookie banners in different countries (visitors in the EU usually get a consent banner first).
  • The tech check compares the site's own words with what its public page loads. Work done on servers, in private code or in separate apps isn't visible here, so 'nothing found' means not visible on the public page, not that it doesn't exist.
  • This text was written from fixed templates because no AI writer was available. It uses exactly the same evidence.
  • The code reader hit its size budget on parts of 7 large bundle file(s); those parts weren't fully analysed.

Facts, not judgements: this page describes what the code and traffic show, not anyone's intent. Not financial advice. Case id jEnzot8C.