MM2 Trade Calculator

Trade calculator for Murder Mystery 2 values, scraped from Supreme Values.

Artifact	Purpose
scrape_mm2_values.py	Scrapes values into mm2_values.json
build_trade_calculator.py	Rebuilds trade_calculator.html from that JSON
trade_calculator.html	Standalone calculator (open in any browser)
roblox_oauth.js / oauth_callback.html	Browser Sign in with Roblox (App permissions)
roblox_account.js	Account button / modal on the calculator
auth_server.py	Optional local username-link helper
calculator_overlay.py	Optional always-on-top Windows overlay

Repo: https://github.com/lunixical-hash/trade-calculator
Live site: https://lunixical-hash.github.io/trade-calculator/

Values are sourced from Supreme Values.

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Use the calculator (no install)

Option A — open the file

1. Clone or download this repo.
2. Double-click trade_calculator.html, or open it from your browser (File → Open).

Option B — GitHub Pages (one-click)

https://lunixical-hash.github.io/trade-calculator/

That serves index.html, which redirects to the calculator. Direct link:

https://lunixical-hash.github.io/trade-calculator/trade_calculator.html

Option C — Windows overlay

python -m pip install -r requirements.txt
python calculator_overlay.py
# or double-click: Start Calculator Overlay.bat

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Scrape values / rebuild the calculator

Setup (once)

cd path\to\trade-calculator
python -m pip install -r requirements.txt
python -m playwright install chromium

Scrape

python scrape_mm2_values.py

Writes mm2_values.json here, and (on Windows) copies to
%LOCALAPPDATA%\Volt\workspace\mm2_values.json when that folder exists.

Rebuild the calculator HTML

After a scrape (or after changing catalog fixes):

python build_trade_calculator.py

Opens as trade_calculator.html (and is what Pages serves).

Optional hourly scrape (Windows Task Scheduler)

1. Task Scheduler → Create Basic Task → e.g. MM2 Values Scraper
2. Trigger: Daily → then edit to Repeat every 1 hour
3. Action: Start a program
   • Program: python
   • Arguments: scrape_mm2_values.py
   • Start in: your clone path
4. Run the task once to verify

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Connect a Roblox account (App permissions)

Visitors sign in with the normal Roblox Approve / App permissions flow — no commands, no profile codes.

The live site uses browser OAuth (PKCE). After a one-time owner setup, anyone can click Sign in with Roblox.

One-time owner setup

1. Open Roblox Creator → Credentials → create an OAuth 2.0 app
2. Add this Redirect URL exactly:

https://lunixical-hash.github.io/trade-calculator/oauth_callback.html

3. Enable scopes openid and profile
4. Copy the Client ID into auth_public.json:

{
  "clientId": "YOUR_CLIENT_ID_HERE",
  "redirectUri": "https://lunixical-hash.github.io/trade-calculator/oauth_callback.html",
  "scopes": "openid profile"
}

5. Commit + push to main (GitHub Pages updates automatically)

No client secret is needed in the browser. Approved apps show under Roblox Settings → App permissions, same as Bloxlink / Rolimons.

Optional (dev only): username link via auth_server.py

For local testing without OAuth, you can still run python auth_server.py and use username link. End users on the live site do not need this.

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Site updates & version history

GitHub Pages already publishes whatever is on main.

Additionally, .github/workflows/archive-and-publish-site.yml runs whenever live site files change on main and:

• Saves the previous site into versions/<timestamp>/
• Keeps the newest 15 snapshots (older ones are pruned)
• Rebuilds https://lunixical-hash.github.io/trade-calculator/versions/

Rollback: Actions → Archive and publish site → Run workflow → set restore_version to a folder name from /versions/.

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Name mismatches

If a site name doesn't match the in-game inventory name, edit name_map.json:

{
  "Traveler's Gun": "TravelersGun"
}

Left = website name, right = exact MM2 inventory name.

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Publish to GitHub

Create the repo and push (first time)

git init
git add .
git commit -m "Add the MM2 trade calculator"
gh repo create trade-calculator --public --source=. --remote=origin --push

Without gh, create an empty repo on github.com, then:

git remote add origin https://github.com/lunixical-hash/trade-calculator.git
git branch -M main
git push -u origin main

Enable GitHub Pages

UI: Repo → Settings → Pages → Source: Deploy from a branch → Branch: main → Folder: / (root) → Save.

CLI:

gh api repos/lunixical-hash/trade-calculator/pages -X POST -f build_type=legacy -f source[branch]=main -f source[path]=/

Live URL: https://lunixical-hash.github.io/trade-calculator/

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Local JSON (optional)

local HttpService = game:GetService("HttpService")

local function loadValues()
	if not isfile or not isfile("mm2_values.json") then
		return nil
	end
	local ok, data = pcall(function()
		return HttpService:JSONDecode(readfile("mm2_values.json"))
	end)
	if ok then
		return data
	end
	return nil
end

local values = loadValues()
if values then
	print("VampireGun value:", values.items.VampireGun)
end

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Requirements

• Python 3.10+ recommended
• Dependencies: see requirements.txt (playwright, pywebview)