Upload Adapter

image, file, and video share one upload contract. It's a single method:

interface UploadContext {
  signal: AbortSignal;
}
interface UploadResult {
  url: string;
}

Wiring it inCopy Anchor Link

The adapter is always a prop passed to your own NodeView — never hardcoded into the registry component. See Media & AI Node Views for the full ReactNodeViewRenderer wiring; the node view itself calls the core's runUpload/retryUpload helpers, which track in-flight/failed uploads in a PendingUploadRegistry keyed by block id (not position) so retry resends the original File without the user picking again.

RetryCopy Anchor Link

retryUpload (re)starts from the last File passed to runUpload for that block id, or from an explicit override — the same path covers "attach a file to an empty placeholder" when nothing has been attempted yet. A completed upload dispatches with addToHistory: false, so it never becomes a separate undo step.

Mapping the result onto the nodeCopy Anchor Link

By default a successful upload stores result.url as the node's src. Pass toAttrs to the image/file/video options to persist more of what your server returns — it runs on the first success and on every retry, and its attrs are merged over the node's existing ones (so file's name/size/mime, read from the picked File at insert, survive unless you override them):

interface StoredUpload extends UploadResult {
  name: string;
  size: number;
  mime: string;
}

createBlockKit({
  file: {
    toAttrs: (result) => {
      const { url, name, size, mime } = result as StoredUpload;
      return { src: url, name, size, mime };
    },
  },
});

Signed URLs and files behind authCopy Anchor Link

resolveSrc (on image, file, video, and embed) rewrites a stored URL for display only:

Image.configure({
  resolveSrc: (src, node) => signUrl(src), // string or Promise<string>
});

The document — getHTML(), markdown, JSON, Yjs — keeps the canonical stored src (url for embed); persisting a short-lived signed URL would break every later reader. Only node views apply it: the registry node views do, through useResolvedSrc from @slash-editor/react, which you can call from your own node view too. An async result renders nothing until it settles (the raw URL is never requested meanwhile), a result for a since-changed src is discarded, and a thrown error or rejection falls back to the stored URL.