diff --git a/bincio/serve/server.py b/bincio/serve/server.py
index 2c19563..551021d 100644
--- a/bincio/serve/server.py
+++ b/bincio/serve/server.py
@@ -648,13 +648,43 @@ async def admin_reextract_originals(
 
     def event_stream():
         from bincio.extract.strava_api import strava_to_parsed
-        from bincio.extract.ingest import ingest_parsed
+        from bincio.extract.metrics import compute as compute_metrics
+        from bincio.extract.writer import (
+            build_summary, make_activity_id, write_activity,
+            write_index, write_athlete_json,
+        )
         from bincio.render.merge import merge_all
 
+        # Immediate heartbeat so the client knows the connection is alive
+        yield f"data: {json.dumps({'type': 'status', 'message': f'Found {total} originals, starting extraction…'})}\n\n"
+
         imported = 0
         skipped = 0
         errors = 0
-        any_imported = False
+
+        # Load existing index once upfront (to preserve any non-Strava activities)
+        index_path = user_dir / "index.json"
+        if index_path.exists():
+            try:
+                existing_index = json.loads(index_path.read_text(encoding="utf-8"))
+            except Exception:
+                existing_index = {}
+        else:
+            existing_index = {}
+
+        owner = existing_index.get("owner", {"handle": handle})
+        # Seed summaries from whatever already exists in activities/
+        summaries: dict[str, Any] = {s["id"]: s for s in existing_index.get("activities", [])}
+
+        _COMPUTED = {"bas_version", "generated_at", "power_curve", "records", "best_climbs"}
+        athlete_config: dict[str, Any] = {}
+        athlete_path = user_dir / "athlete.json"
+        if athlete_path.exists():
+            try:
+                existing_athlete = json.loads(athlete_path.read_text(encoding="utf-8"))
+                athlete_config = {k: v for k, v in existing_athlete.items() if k not in _COMPUTED}
+            except Exception:
+                pass
 
         for n, orig_path in enumerate(original_files, 1):
             try:
@@ -664,28 +694,36 @@ async def admin_reextract_originals(
                 name = meta.get("name", orig_path.stem)
 
                 parsed = strava_to_parsed(meta, streams)
-
-                from bincio.extract.writer import make_activity_id
                 activity_id = make_activity_id(parsed)
+
                 if (user_dir / "activities" / f"{activity_id}.json").exists():
                     skipped += 1
                     yield f"data: {json.dumps({'type': 'progress', 'n': n, 'total': total, 'name': name, 'status': 'skipped'})}\n\n"
                     continue
 
-                ingest_parsed(parsed, user_dir, privacy="public", rdp_epsilon=0.0001)
+                metrics = compute_metrics(parsed)
+                effective_privacy = parsed.privacy if parsed.privacy is not None else "public"
+                write_activity(parsed, metrics, user_dir, privacy=effective_privacy, rdp_epsilon=0.0001)
+                summary = build_summary(parsed, metrics, activity_id, effective_privacy)
+                summaries[activity_id] = summary
+
                 imported += 1
-                any_imported = True
                 yield f"data: {json.dumps({'type': 'progress', 'n': n, 'total': total, 'name': name, 'status': 'imported'})}\n\n"
             except Exception as exc:
                 errors += 1
                 log.error("reextract[%s]: failed on %s: %s", handle, orig_path.name, exc, exc_info=True)
                 yield f"data: {json.dumps({'type': 'progress', 'n': n, 'total': total, 'name': orig_path.stem, 'status': 'error', 'detail': str(exc)})}\n\n"
 
-        log.info("reextract[%s]: done — imported=%d skipped=%d errors=%d", handle, imported, skipped, errors)
-        if any_imported:
+        # Write index and athlete.json once at the end (not once per activity)
+        if imported > 0:
+            yield f"data: {json.dumps({'type': 'status', 'message': 'Writing index and athlete data…'})}\n\n"
+            write_index(list(summaries.values()), user_dir, owner)
+            write_athlete_json(list(summaries.values()), user_dir, athlete_config)
+            yield f"data: {json.dumps({'type': 'status', 'message': 'Running merge and rebuild…'})}\n\n"
             merge_all(user_dir)
             _trigger_rebuild(handle)
 
+        log.info("reextract[%s]: done — imported=%d skipped=%d errors=%d", handle, imported, skipped, errors)
         yield f"data: {json.dumps({'type': 'done', 'imported': imported, 'skipped': skipped, 'errors': errors})}\n\n"
 
     return StreamingResponse(
diff --git a/site/src/pages/admin/index.astro b/site/src/pages/admin/index.astro
index 827c6ac..bfa792d 100644
--- a/site/src/pages/admin/index.astro
+++ b/site/src/pages/admin/index.astro
@@ -190,13 +190,15 @@ import Base from '../../layouts/Base.astro';
 
         let imported = 0, skipped = 0, errors = 0;
         try {
-          const es = new EventSource(`/api/admin/users/${h}/reextract-originals`);
-          // EventSource only does GET; use fetch + ReadableStream instead
-          es.close();
-
           const r = await fetch(`/api/admin/users/${h}/reextract-originals`, {
             method: 'POST', credentials: 'include',
           });
+          if (!r.ok) {
+            const errText = await r.text().catch(() => r.status.toString());
+            reextractSummary.textContent = `Error ${r.status}: ${errText}`;
+            reextractClose.disabled = false;
+            return;
+          }
           const reader = r.body!.getReader();
           const decoder = new TextDecoder();
           let buf = '';
@@ -210,7 +212,9 @@ import Base from '../../layouts/Base.astro';
               const dataLine = chunk.split('\n').find(l => l.startsWith('data: '));
               if (!dataLine) continue;
               const ev = JSON.parse(dataLine.slice(6));
-              if (ev.type === 'progress') {
+              if (ev.type === 'status') {
+                reextractSummary.textContent = ev.message;
+              } else if (ev.type === 'progress') {
                 const color = ev.status === 'imported' ? 'text-green-400'
                             : ev.status === 'error'    ? 'text-red-400'
                             : 'text-zinc-500';