From 60588855e7057b663a63a1d2ade36365370a657d Mon Sep 17 00:00:00 2001
From: Vineeth Voruganti <13438633+VVoruganti@users.noreply.github.com>
Date: Fri, 16 Jan 2026 13:32:48 -0500
Subject: [PATCH] chore: Comment for potential debt

---
 src/reconciler/sync_vectors.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/reconciler/sync_vectors.py b/src/reconciler/sync_vectors.py
index 89a3008d..f31d7c38 100644
--- a/src/reconciler/sync_vectors.py
+++ b/src/reconciler/sync_vectors.py
@@ -356,6 +356,15 @@ async def _sync_message_embeddings(
 
     # Step 2: Compute chunk positions for vector IDs
     # Messages can be split into multiple chunks; we need {message_id}_{chunk_position}
+    #
+    # TODO: chunk_position is computed from MessageEmbedding row ordering by ID, which is
+    # fragile. If rows are deleted and re-created (e.g., during re-embedding), IDs change
+    # and positions shift, potentially causing vector ID mismatches with the external store.
+    # This doesn't break search (metadata.message_id is used, not vector ID), but can leave
+    # stale vectors. Consider either:
+    # 1. Persisting chunk_position in the MessageEmbedding table
+    # 2. Removing MessageEmbedding table entirely if it becomes unnecessary
+    # See: https://github.com/plastic-labs/honcho/issues/XXX
     message_ids = list({emb.message_id for emb in embeddings})
     sibling_stmt = (
         select(models.MessageEmbedding.id, models.MessageEmbedding.message_id)