@ose-foundry-core/types

TypeScript types for the Old-School Essentials (OSE) Foundry VTT system.

This package is intentionally minimal in its initial release. It re-exports only the types that are already explicitly declared in OSE's TypeScript source — config unions, the character helper-class interfaces, and the character class definitions. The shipped surface grows automatically as the system's remaining .js data models are converted to .ts.

The package ships a single declaration-only entrypoint (index.d.ts). It contains no runtime code.

Install

npm i -D @ose-foundry-core/types
# or pnpm add -D @ose-foundry-core/types

Required peer

This package needs @league-of-foundry-developers/foundry-vtt-types (Foundry's
type definitions) to be present. On npm 7+ and pnpm 8+ it installs
automatically — you don't need to do anything extra.

What's exported

As of 6-12-2026:

| Group | Types | | --------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ | | Config unions (from src/module/config.ts) | OseConfig, Save, Armor, Attribute, ExplorationSkill, RollType, Color, InventoryItemTag, EncumbranceOption, ApplyDamageOption | | Character helper interfaces (from src/module/actor/data-model-classes/*.ts) | CharacterScores, CharacterAC, CharacterMove, CharacterEncumbrance, CharacterSpells | | Classes (from src/types/classes.ts) | ClassicClassName, OseClass |

Usage

import type { Save, CharacterScores, ClassicClassName } from "@ose-foundry-core/types";

function rollSave(scoreType: Save) { /* … */ }

const klass: ClassicClassName = "Magic-User";   // ✓
// const bad: ClassicClassName = "Sorcerer";    // ✗ type error

Roadmap

As the system migrates its .js data models to .ts, the explicit type definitions in those files become eligible for re-export here. Likely future additions, in roughly the order they'd land:

• WeaponSystemData, ItemSystemData, ArmorSystemData, SpellSystemData, AbilitySystemData, ContainerSystemData — when src/module/item/data-model-*.js move to TypeScript
• CharacterSystemData / MonsterSystemData (and their *Source variants) — when the actor data models migrate
• Document-level convenience types (e.g. OseCharacter = Actor & { type: "character"; … }) — once the system data shapes are available to compose with

Maintenance

index.d.ts is generated — do not edit it. It is produced from
src/types/ in the system repo via npm run build:types (a declaration-only
tsc pass bundled with rollup-plugin-dts).

Releasing

Bump version in packages/types/package.json, then from the repo root run npm run release:types — it rebuilds index.d.ts and publishes the package to npm.

Publishing needs an npm account with publish rights to the @ose-foundry-core scope (the scope/org must already exist on npm). Run npm login first, then the release script.

The package sets publishConfig.access: public, so the first publish creates the scoped package as public — no extra flags needed.