@vttforge/core

The runtime half of VTTForge: what a Foundry VTT v14+ system or module imports. A module reaches for everything below, plus the four rows marked for modules.

bun add @vttforge/core

What is in it

| Export | What it replaces | |---|---| | registerSystem / registerModule | The Hooks.once("init") block: data models, document classes, initiative, status effects, sheets, enrichers, and ready | | BaseTypeDataModel(defineSchema) | A TypeDataModel whose fields are typed from the schema, so this.level is a number inside prepareDerivedData | | fields() | foundry.data.fields, typed, read lazily so the module imports in Node | | InferSchema<T> / Model['$inferData'] | The hand-written interface that drifts from the schema | | BaseActorSheet() / BaseItemSheet() | static TABS, static DRAG_DROP, static MODES (play and edit, with the fields locked in play), typed onDropItem and friends on ActorSheetV2 / ItemSheetV2 with Handlebars | | resourceField() | The { value, max } field a token bar reads, typed as two numbers; registerSystem checks the manifest's bars against it | | postRoll() | Posts a roll as a chat card, tagged as a critical or a fumble by the thresholds you give | | dicePool() / stepDie() / countSuccesses() | The pool formula from a description, a die stepped along a ladder, successes counted on any roll | | promptFields() | A dialog from a list of fields, built with Foundry's input helpers, resolving to a typed object or null | | keywords on either registration | Rules terms as @Keyword[id] with a tooltip, and a journal entry the GM's client creates and keeps current | | BaseDocumentSheet('Actor' \| 'Item') / BaseApplication() | The same plumbing without Handlebars, for a sheet that builds its own element | | PackageConfig | game.settings.register/get/set with the package id filled in and unregistered reads caught | | createMigrationRunner | The schemaVersion setting, the isNewerVersion compare and the sequential await every system grows | | moduleSubType | The <module id>.<type> prefix Foundry files a module's sub-types under | | registerSocket | The game.socket channel, the manifest flag it needs, the sender id the server vouched for, and requests only a Gamemaster's client can answer | | moduleApi / requireModuleApi | Reading another package's api, and saying which of not installed, switched off or publishing nothing it was | | subTypeDocuments / convertSubTypes | Counting what a module's sub-types hold, and converting them back so uninstalling it strands nothing | | inject | Your own UI inside an application you do not own, replaced on each re-render rather than stacked | | VttfError | Runtime errors with a stable VTTF-NNNN code and a docs URL |

Registering a sheet

import { BaseActorSheet, registerSystem } from '@vttforge/core';

class CharacterSheet extends BaseActorSheet() {
  static PARTS = { sheet: { template: 'systems/my-system/templates/character.hbs' } };
}

registerSystem({
  id: 'my-system',
  actorDataModels: { character: CharacterData },
  sheets: [{ id: 'character', document: 'Actor', sheet: CharacterSheet, types: ['character'], makeDefault: true }],
});

Foundry keys a sheet by its class name and saves that key on every document. A bundler renames classes between builds, so registerSystem uses the id for the key instead.

Docs

• Getting started
• Data models
• Sheets
• Modules
• Sockets. registerSocket: one-way messages, and questions only the Gamemaster's client can answer.
• Error codes

Foundry v14+ only. The package runs in the browser inside Foundry; it reads the Foundry globals lazily, so it also imports cleanly in Node for tests.