diff --git a/.gitignore b/.gitignore
index 4c2041a..4084e06 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,4 +18,4 @@ data/
 # Frontend
 frontend/node_modules/
 frontend/dist/
-frontend/.vite/
\ No newline at end of file
+frontend/.vite/.railway/
diff --git a/backend/capture.py b/backend/capture.py
new file mode 100644
index 0000000..466c7fe
--- /dev/null
+++ b/backend/capture.py
@@ -0,0 +1,72 @@
+"""JSON capture utilities for iOS development."""
+
+import json
+import os
+from datetime import datetime
+from typing import List, Dict, Any
+
+# Output directory for captured JSON
+CAPTURE_DIR = os.path.join(os.path.dirname(__file__), "..", "ios_json_samples")
+
+
+def _ensure_capture_dir():
+    """Ensure the capture directory exists."""
+    os.makedirs(CAPTURE_DIR, exist_ok=True)
+
+
+def _save_json(filename: str, data: Any):
+    """Save data as JSON file."""
+    _ensure_capture_dir()
+    filepath = os.path.join(CAPTURE_DIR, filename)
+    with open(filepath, "w") as f:
+        json.dump(data, f, indent=2, default=str)
+    print(f"[Capture] Saved: {filepath}")
+
+
+def capture_conversation_list(conversations: List[Dict[str, Any]]):
+    """Capture conversation list response."""
+    _save_json("conversation_list.json", conversations)
+
+
+def capture_conversation(conversation: Dict[str, Any]):
+    """Capture single conversation response."""
+    _save_json(f"conversation_{conversation.get('id', 'unknown')[:8]}.json", conversation)
+
+
+def capture_full_response(stage1: List[Dict], stage2: List[Dict], stage3: Dict, metadata: Dict):
+    """Capture full council response."""
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+    _save_json(f"full_response_{timestamp}.json", {
+        "stage1": stage1,
+        "stage2": stage2,
+        "stage3": stage3,
+        "metadata": metadata
+    })
+
+
+def capture_sse_events(events: List[Dict[str, Any]]):
+    """Capture SSE stream events."""
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+    _save_json(f"sse_events_{timestamp}.json", events)
+
+
+def capture_stage1(results: List[Dict[str, Any]]):
+    """Capture Stage 1 results."""
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+    _save_json(f"stage1_{timestamp}.json", results)
+
+
+def capture_stage2(rankings: List[Dict], label_to_model: Dict, aggregate_rankings: List[Dict]):
+    """Capture Stage 2 results."""
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+    _save_json(f"stage2_{timestamp}.json", {
+        "rankings": rankings,
+        "label_to_model": label_to_model,
+        "aggregate_rankings": aggregate_rankings
+    })
+
+
+def capture_stage3(result: Dict[str, Any]):
+    """Capture Stage 3 result."""
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+    _save_json(f"stage3_{timestamp}.json", result)