Shadcn Attachments

useCourier is headless, so it can provide upload behavior for a Shadcn attachment interface without taking a dependency on Shadcn or dictating how attachments look.

This integration separates responsibilities:

• useCourier manages uploads, progress, status, retries, and cancellation.
• Your attachment component manages previews, layout, buttons, and styling.

Connect the upload state

The core wiring uses the values returned by useCourier:

const { files, addFile, retryUpload, removeFile } = useCourier({
  url: "/api/uploads",
});

Connect the attachment component's file-selection event to addFile:

function handleFilesSelected(selectedFiles: File[]) {
  selectedFiles.forEach((file) => {
    void addFile(file);
  });
}

Render each attachment from the corresponding UploadItem:

Attachment UI	useCourier value
File name and preview	item.file
Progress indicator	item.uploadProgress
Upload state	item.status
Retry action	retryUpload(item.id)
Remove or cancel action	removeFile(item.id)

Display upload states

Use item.status to choose the appropriate attachment state:

function getAttachmentState(status: UploadItem["status"]) {
  switch (status) {
    case "uploading":
      return "Uploading";
    case "processing":
      return "Processing";
    case "done":
      return "Uploaded";
    case "error":
      return "Upload failed";
    default:
      return "Ready";
  }
}

For an error state, show a retry action using the file's tracked ID. For an active upload, removeFile aborts the request before removing the attachment from the tracked list.

Complete example

The following component connects useCourier to Shadcn's attachment components. The attachment components and formatFileSize helper belong to the consuming application.

import React from "react";
import {
  Attachment,
  AttachmentAction,
  AttachmentActions,
  AttachmentContent,
  AttachmentDescription,
  AttachmentGroup,
  AttachmentMedia,
  AttachmentTitle,
} from "@/components/ui/attachment";
import { Spinner } from "@/components/ui/spinner";
import { FileIcon, RefreshCwIcon, XIcon } from "lucide-react";
import { useCourier } from "use-courier";
import { formatFileSize } from "@/lib/utils";

export function FileUpload() {
  const fileInputRef = React.useRef<HTMLInputElement>(null);
  const { addFile, files, removeFile, retryUpload } = useCourier({
    url: "http://localhost:3000/upload",
    fileChunking: {
      route: "http://localhost:3000/upload/chunk",
      threshold: 100 * 1024 * 1024,
      chunkSize: 10 * 1024 * 1024,
    },
    onUploadError({ error }) {
      console.error(error.message);
    },
  });

  function handleFileChange(event: React.ChangeEvent<HTMLInputElement>) {
    const selectedFiles = Array.from(event.target.files ?? []);
    selectedFiles.forEach((file) => void addFile(file));
  }

  function handleRemove(id: string) {
    removeFile(id);
    if (fileInputRef.current) fileInputRef.current.value = "";
  }

  return (
    <main>
      <p>File Upload</p>
      <input
        ref={fileInputRef}
        type="file"
        multiple
        onChange={handleFileChange}
      />

      <AttachmentGroup className="flex flex-col gap-4">
        {files.map((item) => (
          <Attachment
            key={item.id}
            state={item.status}
            className="w-full max-w-xs"
          >
            <AttachmentMedia>
              {item.status === "uploading" || item.status === "processing" ? (
                <Spinner />
              ) : (
                <FileIcon />
              )}
            </AttachmentMedia>
            <AttachmentContent>
              <AttachmentTitle>{item.file.name}</AttachmentTitle>
              <AttachmentDescription>
                {item.status === "uploading"
                  ? `Uploading - ${item.uploadProgress}%`
                  : `${item.file.type} - ${formatFileSize(item.file.size)}`}
              </AttachmentDescription>
            </AttachmentContent>
            <AttachmentActions>
              {item.status === "error" && (
                <AttachmentAction
                  aria-label="Retry upload"
                  onClick={() => void retryUpload(item.id)}
                >
                  <RefreshCwIcon />
                </AttachmentAction>
              )}
              <AttachmentAction
                aria-label={`Remove ${item.file.name}`}
                onClick={() => handleRemove(item.id)}
              >
                <XIcon />
              </AttachmentAction>
            </AttachmentActions>
          </Attachment>
        ))}
      </AttachmentGroup>
    </main>
  );
}

Keep the integration optional

This recipe does not require Shadcn at the package level. You can use the same mapping with another attachment component or a custom upload interface. The important boundary is that the UI reads from files and sends user actions back through addFile, retryUpload, and removeFile.