diff --git a/src/index.ts b/src/index.ts
index 904e08fe..69ab0c9a 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -412,16 +412,24 @@ async function main() {
   const needsRebuild = bm25Index.size === 0;
 
   if (needsRebuild) {
-    const indexCount = await rebuildIndex(kv).catch((err) => {
-      console.warn(`[agentmemory] Failed to rebuild search index:`, err);
-      return 0;
-    });
-    if (indexCount > 0) {
-      bootLog(
-        `Search index rebuilt: ${indexCount} entries`,
-      );
-      indexPersistence.scheduleSave();
-    }
+    // Fire-and-forget. rebuildIndex iterates every observation across
+    // every session and AWAITS an embedding-provider call per record.
+    // On a large corpus + rate-limited embedding endpoint that can
+    // take HOURS; awaiting it here blocks every subsequent boot step
+    // (including startViewerServer below, leaving the viewer port
+    // unbound for the duration). The index lazily fills in over time
+    // and search degrades gracefully — partial coverage > no viewer
+    // for hours. Errors still surface via the inner .catch.
+    void rebuildIndex(kv)
+      .then((indexCount) => {
+        if (indexCount > 0) {
+          bootLog(`Search index rebuilt: ${indexCount} entries`);
+          indexPersistence.scheduleSave();
+        }
+      })
+      .catch((err) => {
+        console.warn(`[agentmemory] Failed to rebuild search index:`, err);
+      });
   } else {
     // Backfill memories into BM25 for users upgrading from <0.9.5: prior
     // versions of mem::remember never indexed memories, so the persisted