Getting Started

Requirements

• Node.js >= 24 (see engines in package.json)

Installation

npm install uesp-eso-build-wrapper

Game data

Game data (UespInitData) is not bundled in the npm package — the library ships only the engine scripts. You supply the data when initializing.

The canonical source is vendor/uesp-data/uesp-game-data.json, committed to the repository and regenerated from UESP SQL dumps after each ESO patch. Its _meta field records which patch it was generated from — pin or update your copy deliberately so your numbers always match a known game version.

Ways to obtain it:

1. Copy from the repo — download uesp-game-data.json from the repository above and load it with fs.readFileSync.

2. Generate it yourself — the wrapper ships a self-contained pipeline that parses the UESP MariaDB dumps directly (no external project required), using the same Node >= 24 runtime as the library:

   npm run db:seed -- --dir /path/to/dumps --version <patch>

   (Or seed a SQLite DB and use the older npm run generate-data -- --db /path/to/local.db --version <patch>.)

Initialize the engine

Call initEsoEngineFromData() once per process, before any calculation. Subsequent calls are no-ops.

import fs from 'fs';
import { initEsoEngineFromData } from 'uesp-eso-build-wrapper';
import type { UespInitData } from 'uesp-eso-build-wrapper';

const initData = JSON.parse(
  fs.readFileSync('uesp-game-data.json', 'utf-8'),
) as UespInitData;

initEsoEngineFromData({ initData });

Your first calculation

import { calculateBuild } from 'uesp-eso-build-wrapper';

const stats = calculateBuild({
  character: {
    race: 'High Elf',
    class: 'Sorcerer',
    level: 50,
    attributes: { health: 0, magicka: 64, stamina: 0 },
  },
});

console.log(stats.Health);       // 16000
console.log(stats.Magicka);      // 19104
console.log(stats.MagickaRegen); // 514
console.log(stats.SpellDamage);  // 1000

The result object also carries stats.raw — all 204 stats as a plain record. See Reading the Output.

Next steps

• Character — every character-sheet field
• Items & Equipment — gear from the UESP item API
• Champion Points — CP nodes
• Buffs & Toggle Skills — named buffs and toggles
• Skills & Passives — skill bars, morphs, passives