diff --git a/packages/ui-common/src/components/SmartFileInput/index.tsx b/packages/ui-common/src/components/SmartFileInput/index.tsx
index d39e431c7..0da3e2f37 100644
--- a/packages/ui-common/src/components/SmartFileInput/index.tsx
+++ b/packages/ui-common/src/components/SmartFileInput/index.tsx
@@ -11,6 +11,7 @@ import {
 } from "lucide-react";
 import { cn } from "../../lib/utils";
 import { Button } from "../button";
+import type { ViewableFile } from "../FileViewer";
 
 export interface SmartFileInputProps {
   /** The settings object containing features and their upload fields config. */
@@ -35,8 +36,18 @@ export interface SmartFileInputProps {
    */
   existingFiles?: Record<
     string,
-    { name: string; url: string; size?: number }[]
+    { name: string; url: string; size?: number; mimeType?: string | null }[]
   >;
+  /**
+   * When provided, already-uploaded files render as buttons that call this with
+   * the file instead of opening a new browser tab. Wire it to `useFileViewer`'s
+   * `view` to preview documents inline:
+   *
+   *   const { view, viewer } = useFileViewer();
+   *   <SmartFileInput ... onViewFile={view} />
+   *   {viewer}
+   */
+  onViewFile?: (file: ViewableFile) => void;
   /** Disabled state for the entire file input group. */
   disabled?: boolean;
   /** Display variant style. Default is "default" (large dropzone). Minimal renders a compact upload button. */
@@ -80,6 +91,68 @@ function FileIcon({ name, className }: { name: string; className?: string }) {
   return <File className={cn("text-slate-400", className)} />;
 }
 
+type ExistingFile = {
+  name: string;
+  url: string;
+  size?: number;
+  mimeType?: string | null;
+};
+
+/**
+ * A single already-uploaded file. Renders a click-to-view button when
+ * `onViewFile` is set (inline preview via the FileViewer), otherwise a plain
+ * new-tab anchor.
+ */
+function ExistingFileLink({
+  file: f,
+  onViewFile,
+  className,
+  showSize = false,
+}: {
+  file: ExistingFile;
+  onViewFile?: (file: ViewableFile) => void;
+  className?: string;
+  showSize?: boolean;
+}) {
+  const label =
+    showSize && typeof f.size === "number"
+      ? `${f.name} (${formatBytes(f.size)})`
+      : f.name;
+
+  if (onViewFile) {
+    return (
+      <button
+        type="button"
+        onClick={(e) => {
+          e.stopPropagation();
+          onViewFile({ name: f.name, url: f.url, mimeType: f.mimeType });
+        }}
+        className={cn(
+          "relative z-10 text-left text-xs text-primary hover:underline truncate max-w-xs",
+          className,
+        )}
+      >
+        {label}
+      </button>
+    );
+  }
+
+  return (
+    <a
+      href={f.url}
+      target="_blank"
+      rel="noopener noreferrer"
+      onClick={(e) => e.stopPropagation()}
+      className={cn(
+        "relative z-10 text-xs text-primary hover:underline truncate max-w-xs",
+        className,
+      )}
+    >
+      {label}
+    </a>
+  );
+}
+
 export function SmartFileInput({
   file,
   value,
@@ -87,6 +160,7 @@ export function SmartFileInput({
   errors,
   uploadedKeys,
   existingFiles,
+  onViewFile,
   disabled = false,
   variant = "default",
   className,
@@ -433,15 +507,11 @@ export function SmartFileInput({
                     {existingForField.length > 0 && (
                       <div className="flex flex-col gap-1 basis-full">
                         {existingForField.map((f, idx) => (
-                          <a
+                          <ExistingFileLink
                             key={`${f.url}-${idx}`}
-                            href={f.url}
-                            target="_blank"
-                            rel="noopener noreferrer"
-                            className="text-xs text-primary hover:underline truncate max-w-xs"
-                          >
-                            {f.name}
-                          </a>
+                            file={f}
+                            onViewFile={onViewFile}
+                          />
                         ))}
                       </div>
                     )}
@@ -488,19 +558,12 @@ export function SmartFileInput({
                       {existingForField.length > 0 ? (
                         <div className="mt-0.5 flex flex-col gap-0.5">
                           {existingForField.map((f, idx) => (
-                            <a
+                            <ExistingFileLink
                               key={`${f.url}-${idx}`}
-                              href={f.url}
-                              target="_blank"
-                              rel="noopener noreferrer"
-                              onClick={(e) => e.stopPropagation()}
-                              className="relative z-10 text-xs text-primary hover:underline truncate max-w-xs"
-                            >
-                              {f.name}
-                              {typeof f.size === "number"
-                                ? ` (${formatBytes(f.size)})`
-                                : ""}
-                            </a>
+                              file={f}
+                              onViewFile={onViewFile}
+                              showSize
+                            />
                           ))}
                         </div>
                       ) : (
diff --git a/packages/ui-common/src/hooks/useFileViewer.tsx b/packages/ui-common/src/hooks/useFileViewer.tsx
new file mode 100644
index 000000000..68269f7cf
--- /dev/null
+++ b/packages/ui-common/src/hooks/useFileViewer.tsx
@@ -0,0 +1,27 @@
+import { useCallback, useState } from "react";
+import { FileViewerModal, type ViewableFile } from "../components/FileViewer";
+
+/**
+ * Drives a single shared {@link FileViewerModal} for a page. Call `view(file)`
+ * from any file row to open the document inline (pdf / image / video / office /
+ * text); render `viewer` once near the page root.
+ *
+ *   const { view, viewer } = useFileViewer();
+ *   <Button onClick={() => view({ name, url, mimeType })}>View</Button>
+ *   {viewer}
+ *
+ * Pass `view` straight into `SmartFileInput`'s `onViewFile` prop to make its
+ * already-uploaded files open in the viewer instead of a new tab.
+ */
+export function useFileViewer() {
+  const [file, setFile] = useState<ViewableFile | null>(null);
+
+  const view = useCallback((f: ViewableFile) => setFile(f), []);
+  const close = useCallback(() => setFile(null), []);
+
+  const viewer = (
+    <FileViewerModal open={file !== null} file={file} onClose={close} />
+  );
+
+  return { view, close, viewer };
+}
diff --git a/packages/ui-common/src/index.ts b/packages/ui-common/src/index.ts
index 2e8779076..43c39d962 100644
--- a/packages/ui-common/src/index.ts
+++ b/packages/ui-common/src/index.ts
@@ -20,6 +20,8 @@ export type {
   ViewableFile,
 } from "./components/FileViewer";
 
+export { useFileViewer } from "./hooks/useFileViewer";
+
 export { OperationDatePicker } from "./components/OperationDatePicker";
 export type { OperationDatePickerProps } from "./components/OperationDatePicker";