The root and /legacy declarations retain the complete npm 1.0.0 and 1.1.0 type shape, including known mistakes. Existing TypeScript consumers do not need to change imports as part of this migration. Both releases used the same declarations. The generated online-editor global also preserves this historical surface.

For accurate types, explicitly opt into the additive entry:

import jassub from 'artplayer-plugin-jassub/runtime'

const register = jassub({
  workerUrl: '/assets/jassub-worker.js',
  wasmUrl: '/assets/jassub-worker.wasm',
  modernWasmUrl: '/assets/jassub-worker-modern.wasm',
  subUrl: '/subtitles.ass',
})
// Add register to the existing Artplayer plugins option.
// When called with an Artplayer, it synchronously returns { name, instance }.

/runtime uses the same JavaScript file as the root entry. It does not change defaults, wrap instances, download resources differently or introduce a second implementation. URLs are optional because the vendor has defaults; this does not mean its default relative URLs will exist on your site. Continue hosting compatible worker, WASM and font files and supplying the paths your deployment needs.

Area	Historical root types	Accurate `/runtime` types and existing JavaScript
Factory options	Required, with three required URLs	Optional options; optional resource URLs
Instance resize	force, width, height, top, left	width, height, top, left, force
resize/setVideo/destroy	Promise	Synchronous; no-argument calls return void
sendMessage	Unchecked extension	Promise, resolves after posting, not after Worker completion
Events/styles	Unchecked extension	Typed callbacks and partial mutation objects
ASS event Style	Unchecked extension	Numeric libass style index
ASS Start/Duration	Unchecked extension	Milliseconds; setCurrentTime uses seconds
Unknown fields/methods	Existing any indexes	Named supported fields; unknown members rejected

Switching to /runtime intentionally changes type inference. For example, instance.resize(640, 360, 0, 0, true) describes the actual call order. await instance.destroy() remains legal JavaScript, but .then() on that result never worked at runtime. Resource teardown completion is not represented by a Promise. The callback error channel is Error | Event | null; ErrorEvent is included, and real CSP Worker failures can deliver a plain Event. Requests clean their listeners/timer before calling the consumer once. Destroy settles pending callbacks with an Error and undefined data after all request resources are removed, even if another callback throws. Query outputs do not contain the upstream npm declaration's _index. Issue queries after ready; the Worker protocol still identifies responses by target, not a new request ID.

The accurate instance extends EventTarget and preserves its normal listener APIs. destroy(error) returns the original Error, or converts a nonempty string to Error; an empty string is returned unchanged. Direct destruction is idempotent, and queued sendMessage operations settle without posting after destruction. Lifecycle and the limited media-time fallback for zero frame counters are documented in ARCHITECTURE.md.

NodeNext ESM retains the root declaration's historical CommonJS namespace behavior. If existing code uses the root namespace's .default to satisfy that declaration, keep that form or opt into /runtime, whose conditional .d.mts is directly callable. CommonJS accurate types use import jassub = require('artplayer-plugin-jassub/runtime'). Do not invent jassub.default: the current JavaScript factory has no self alias. Older TypeScript resolves /legacy and /runtime through exact typesVersions mappings. Existing direct declaration paths are retained; no wildcard remaps unrelated paths.

Maintain runtime-api.d.ts against the recorded base plus local wrapper patches and actual worker behavior, not a new upstream version. Keep CJS/ESM entry aliases synchronized. Run yarn test:jassub-types, yarn test:jassub-types-package, yarn test:jassub, and yarn typecheck after changes. The package runner installs actual historical archives and the candidate outside the workspace, checks strict positive/negative consumers, and verifies artifact identity. This is type/distribution evidence, not browser playback or final release acceptance.