How a WoW run ends up on a website

The addon keeps the diary

WoW announces almost everything that happens through events: you gained XP, a quest was turned in, something died. NickHub Tracker is about 430 lines of Lua, the language WoW addons are written in. It subscribes to 17 of those events and writes down the ones that matter for a leveling run:

Logged	Details
Level-ups	Time, /played, zone and gold
Kills	Mob, type, level, XP and zone, including pet kills
Quests	Title, XP, money and how long the quest was held
Deaths	Who or what did it, where, and at what level
Travel	Each zone change, plus pet deaths and session times

Working out which kills are yours

The combat log says when something dies, but not who gets credit. So the addon tags any NPC that you or your pet hurts. If a tagged mob dies later, that's a kill.

-- anything I (or my pet) do to an NPC marks it as "mine"
if isMine(srcFlags) and npcKey(dstGUID) and (DAMAGE[sub] or sub:find("^SPELL_AURA_APPLIED")) then
  if not tagged[dstGUID] then tagged[dstGUID] = { name = dstName, t = GetTime() } end
end

From the addon. Every creature has a unique ID, so two wolves with the same name never get mixed up.

Matching XP to the right kill

The game doesn't include XP in the death event. It arrives separately as a chat message, the same "dies, you gain 50 experience" line you see in game, and it can land just before or just after the death. The addon reads that message and pairs it with the matching mob name within a three-second window, whichever arrives first. The message pattern comes from the game's own text, so it isn't tied to English.

Everything else the game doesn't hand over

• Mob levels and types aren't in the combat log either. The addon learns them whenever a mob is targeted, moused over or shows a nameplate.
• /played normally prints to chat. The addon requests it silently after each level-up, so the time is exact and chat stays clean.
• Cause of death is the last thing that hit you, and that includes the environment, such as falling or lava.
• XP sources are split by adding up mob XP and quest XP separately, while the total comes from the XP bar itself.

The workaround at the center of it all

Addons run in a locked-down sandbox with no internet access and no general file access. Their only way to keep anything is a saved variables file, and WoW only writes that to disk on logout or a UI reload.

That one rule shapes the whole design. Typing /nh sync forces a UI reload, about three seconds, which makes WoW save the file. If you're in combat, the addon waits until the fight ends, then asks. With /nh auto on, it offers a one-click Sync button after every level-up.

So the addon never touches the internet. It leaves a note in a file, and something outside the game picks it up.

The uploader is the courier

A small Python script, under 300 lines with no extra packages, runs on the PC while you play. Being outside the game, it isn't bound by WoW's rules. Every few seconds it does the following:

• Fingerprints the saved file with a SHA-256 hash, which is a cheap way to tell if anything changed.
• If it did, waits a second so WoW can finish writing.
• Reads the file with its own small Lua parser, since the file is really Lua code rather than a normal data format, and converts it to JSON.
• Sends it to the site with a secret password attached.

The Worker is the doorman

Most websites need a computer running all day waiting for visitors. A Cloudflare Worker flips that. It's a small piece of code, about 70 lines of JavaScript here, that Cloudflare runs on its global network only when a request arrives. There's no server to maintain, and it starts in about a millisecond.

if (url.pathname === "/api/ingest") {
  if (request.method !== "POST") return json({ error: "POST only" }, 405);
  return ingest(request, env);
}
if (url.pathname === "/api/data") return data(env);
return env.ASSETS.fetch(request);

The Worker's whole routing logic: an upload, a request for stats, or the website itself.

• Uploads need the password. The check takes the same time wherever a guess goes wrong, so nobody can work it out one character at a time.
• Storage is Cloudflare KV, a simple key-value database. The whole run lives under one key, data.
• Merging is per character, keeping whichever copy is newest, so uploading from a second WoW install can't wipe another character.

The dashboard does the math

The Worker hands over raw data, and your browser does the rest. Records like fastest level and nemesis, the zone journey and the charts are all worked out on the page when it loads, with Chart.js drawing the graphs. The colors follow the character too: hunters get WoW's hunter green.

Testing a game that wasn't out yet

How do you test a tracker for a run that hasn't happened? A simulator. A test harness fakes WoW's API and runs the real addon through a full 1–60 run, firing kills, quests, deaths and level-ups along the way, then feeds the result through the real uploader's parser. The demo data on the site comes from that run: thousands of kills, all simulated, until the first real sync replaces them.

Good to know

The stack

Part	Built with
Addon	Lua, WoW's addon API
Uploader	Python standard library
Backend	Cloudflare Workers and KV
Dashboard	Plain HTML, CSS and JavaScript, Chart.js

All of it is open to read: view the code on GitHub.