Confirmed upload

Send sequential chunks with Fetch. This same-site example uses the default envelope and a generated 1 MiB Blob, not a personal file.

import { Http, ContentType, uploadConfirmed, type HttpUploadChunkReceipt } from "fetchzen";
const api = Http.create(`${location.origin}/api/examples/`, {
  cache: false, secure: false,
});
const body = new Blob([new Uint8Array(1024 * 1024)]);
const result = await uploadConfirmed(body, {
  sendChunk: async (chunk, { signal }) =>
    (await api.post<Blob, HttpUploadChunkReceipt>("upload-chunk/", chunk, {
      type: ContentType.APPLICATION_OCTET_STREAM, signal, retry: 0,
    })).payload,
  onUploadProgress: (progress) => console.log(progress),
});
console.log(result);

Try this requestServer-confirmed upload

Request parameters

Only Run sends a request to this site's demo API. Use synthetic data only; do not send secrets or personal files. Uploads are counted, not stored.

Run Cancel

Ready. No request sent.

Result

Choose Run to see the response.

Event log

No events yet.

What to notice

Each POST /api/examples/upload-chunk/ reads at most 256 KiB of actual raw body before returning { data: { receivedBytes, stored: false } }. The demo counts and discards bytes; it does not assemble or store files. Progress starts at 0% and advances only on exact receipts, not when bytes are handed to Fetch. done: true means byte receipts, not storage or processing.

The demo limits generated files to 1 MiB. It has no persistence or resume. Use synthetic data: requests pass through Cloudflare. Smaller chunks mean more HTTP round trips. An ordinary whole-file endpoint cannot use this convention without server changes.

Next: production requirements and cancellation or ordinary file upload.