Fix file upload: use Gradio upload endpoint for actual file transfer

Upload files to /gradio_api/upload first to get server paths,
then pass those to the setup endpoint which creates the workspace.
Workspace path persists across questions in the session.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app.py

@@ -316,25 +316,46 @@ CUSTOM_HTML = """
         startBtn.disabled = true;
         startBtn.textContent = 'Uploading...';
 
+        // Step 1: Upload files to Gradio's file endpoint
         var formData = new FormData();
         selectedFiles.forEach(function(f) { formData.append('files', f); });
 
-        fetch(API_BASE + '/gradio_api/call/upload', {
+        fetch(API_BASE + '/gradio_api/upload', {
             method: 'POST',
-            headers: { 'Content-Type': 'application/json' },
-            body: JSON.stringify({ data: [tokenInput.value] })
+            body: formData
+        })
+        .then(function(r) { return r.json(); })
+        .then(function(uploadedPaths) {
+            // Step 2: Call our setup endpoint with the server file paths
+            return fetch(API_BASE + '/gradio_api/call/upload', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ data: [tokenInput.value, uploadedPaths] })
+            });
         })
         .then(function(r) { return r.json(); })
         .then(function(result) {
             return fetch(API_BASE + '/gradio_api/call/upload/' + result.event_id);
         })
         .then(function(r) { return r.text(); })
-        .then(function() {
+        .then(function(text) {
+            var lines = text.split('\\n');
+            var dataLine = lines.find(function(l) { return l.startsWith('data:'); });
+            var parsed = JSON.parse(dataLine.substring(5).trim());
+            var data = JSON.parse(Array.isArray(parsed) ? parsed[0] : parsed);
+            if (data.error) {
+                startBtn.disabled = false;
+                startBtn.textContent = 'Start exploring';
+                alert(data.error);
+                return;
+            }
+            workspacePath = data.workspace_path;
             setupPanel.style.display = 'none';
             chatPanel.style.display = 'block';
             chatInput.focus();
         })
-        .catch(function() {
+        .catch(function(err) {
+            console.error(err);
             startBtn.disabled = false;
             startBtn.textContent = 'Start exploring';
         });
@@ -465,17 +486,22 @@ def build_app() -> gr.Blocks:
             api_name="ask",
         )
 
-        # Upload endpoint (validates token, returns confirmation)
-        upload_input = gr.Textbox(visible=False)
+        # Upload endpoint — accepts file paths from Gradio's /upload, creates workspace
+        upload_token_input = gr.Textbox(visible=False)
+        upload_files_input = gr.File(visible=False, file_count="multiple")
         upload_output = gr.Textbox(visible=False)
 
-        def api_upload(token):
+        def api_upload(token, files):
             if ACCESS_TOKEN and token != ACCESS_TOKEN:
                 return json.dumps({"error": "Invalid access token."})
-            return json.dumps({"ok": True})
+            if not files:
+                return json.dumps({"error": "No files provided."})
+            file_paths = [f.name if hasattr(f, 'name') else str(f) for f in files]
+            workspace = save_uploaded_files(file_paths)
+            return json.dumps({"workspace_path": str(workspace), "file_count": len(file_paths)})
 
         upload_btn = gr.Button(visible=False)
-        upload_btn.click(api_upload, inputs=upload_input, outputs=upload_output, api_name="upload")
+        upload_btn.click(api_upload, inputs=[upload_token_input, upload_files_input], outputs=upload_output, api_name="upload")
 
         # Document viewer endpoint
         doc_input = gr.Textbox(visible=False)