From 9fd016cc9885b2ac729485199be7a18e71b073b6 Mon Sep 17 00:00:00 2001
From: Vjeran Grozdanic <vjeran.grozdanic@sentry.io>
Date: Mon, 3 Aug 2026 13:26:50 +0200
Subject: [PATCH 1/4] ref(ai-monitoring): Align list titles with detail
 selection

Pick one title per conversation by earliest title_source_timestamp
(project_id on ties), and keep the list endpoint up if metadata lookup fails.
---
 src/sentry/ai_monitoring/utils.py             | 40 ++++++-----
 .../organization_ai_conversations.py          | 46 ++++++-------
 tests/sentry/ai_monitoring/test_utils.py      | 68 ++++++++++++++++---
 .../test_organization_ai_conversations.py     | 66 +++++++++++++++++-
 4 files changed, 168 insertions(+), 52 deletions(-)

diff --git a/src/sentry/ai_monitoring/utils.py b/src/sentry/ai_monitoring/utils.py
index 272b9b8ded14..c8e2c5c17095 100644
--- a/src/sentry/ai_monitoring/utils.py
+++ b/src/sentry/ai_monitoring/utils.py
@@ -84,6 +84,10 @@ def clamp_conversation_id_for_storage(conversation_id: str) -> str:
     return conversation_id[:CONVERSATION_ID_TRUNCATE_TO] + "..."
 
 
+# Earliest title source wins (closest to the first user message); project_id breaks ties.
+TITLE_ORDER_BY = (F("title_source_timestamp").asc(nulls_last=True), "project_id")
+
+
 def fetch_conversation_title(
     conversation_id: str,
     project_ids: Collection[int],
@@ -105,18 +109,18 @@ def fetch_conversation_title(
             title__isnull=False,
         )
         .exclude(title="")
-        .order_by(F("title_source_timestamp").asc(nulls_last=True), "project_id")
+        .order_by(*TITLE_ORDER_BY)
         .first()
     )
 
 
 def fetch_conversation_titles(
     conversation_project_pairs: Collection[tuple[str, int]],
-) -> dict[tuple[str, int], str]:
-    """Look up stored titles for the given (conversation_id, project_id) pairs.
+) -> dict[str, str]:
+    """One winning title per conversation_id among the given pairs.
 
-    A conversation id is only unique within a project, so callers must key on the
-    pair. Pairs without a titled row are simply absent from the result.
+    Same selection as ``fetch_conversation_title``. Only requested pairs participate;
+    untitled conversations are absent from the result.
     """
     if not conversation_project_pairs:
         return {}
@@ -127,19 +131,23 @@ def fetch_conversation_titles(
         for conversation_id, _ in requested_pairs
     }
 
-    rows = AIConversationMetadata.objects.filter(
-        project_id__in={project_id for _, project_id in requested_pairs},
-        conversation_id_hash__in=conversation_id_by_hash,
-        title__isnull=False,
-    ).values_list("conversation_id_hash", "project_id", "title")
+    rows = (
+        AIConversationMetadata.objects.filter(
+            project_id__in={project_id for _, project_id in requested_pairs},
+            conversation_id_hash__in=conversation_id_by_hash,
+            title__isnull=False,
+        )
+        .exclude(title="")
+        .order_by(*TITLE_ORDER_BY)
+        .values_list("conversation_id_hash", "project_id", "title")
+    )
 
-    # The filter matches the cross product of the hashes and the projects, so drop
-    # any (conversation, project) combination the caller did not ask about.
-    titles: dict[tuple[str, int], str] = {}
+    # Filter is hashes × projects; drop unrequested pairs. Order makes setdefault win.
+    titles: dict[str, str] = {}
     for row_hash, project_id, title in rows:
-        pair = (conversation_id_by_hash[row_hash], project_id)
-        if title and pair in requested_pairs:
-            titles[pair] = title
+        conversation_id = conversation_id_by_hash[row_hash]
+        if (conversation_id, project_id) in requested_pairs:
+            titles.setdefault(conversation_id, title)
 
     return titles
 
diff --git a/src/sentry/api/endpoints/organization_ai_conversations.py b/src/sentry/api/endpoints/organization_ai_conversations.py
index b716ff7b41e4..2d170ca039e0 100644
--- a/src/sentry/api/endpoints/organization_ai_conversations.py
+++ b/src/sentry/api/endpoints/organization_ai_conversations.py
@@ -1,7 +1,7 @@
 import logging
 import re
 from collections import defaultdict
-from collections.abc import Mapping, Sequence
+from collections.abc import Mapping
 from datetime import datetime
 from typing import Any, TypedDict
 
@@ -80,17 +80,6 @@ def _compute_timestamp_ms(finish_ts: float) -> int:
     return int(finish_ts * 1000) if finish_ts else 0
 
 
-def _first_title(
-    titles: Mapping[tuple[str, int], str], conv_id: str, project_ids: Sequence[int]
-) -> str | None:
-    """Lowest project id with a stored title wins, so results are stable across requests."""
-    for project_id in project_ids:
-        title = titles.get((conv_id, project_id))
-        if title is not None:
-            return title
-    return None
-
-
 def _extract_first_user_message(messages: Any) -> str | None:
     """Extract first user message, handling both old (content) and new (parts) formats."""
     if isinstance(messages, str) and messages == FILTERED:
@@ -592,17 +581,24 @@ def _apply_titles(
         conversations_map: dict[str, dict[str, Any]],
         project_ids_by_conversation: Mapping[str, set[int]],
     ) -> None:
-        """Attach stored conversation titles, leaving `title` as None when we have none."""
-        sorted_project_ids = {
-            conv_id: sorted(project_ids_by_conversation.get(conv_id, ()))
+        """Set each conversation's `title` from storage when present.
+
+        On lookup failure, log and leave titles unset so the list response still succeeds.
+        """
+        pairs = [
+            (conv_id, project_id)
             for conv_id in conversations_map
-        }
-        titles = fetch_conversation_titles(
-            [
-                (conv_id, project_id)
-                for conv_id, project_ids in sorted_project_ids.items()
-                for project_id in project_ids
-            ]
-        )
-        for conv_id, conversation in conversations_map.items():
-            conversation["title"] = _first_title(titles, conv_id, sorted_project_ids[conv_id])
+            for project_id in project_ids_by_conversation.get(conv_id, ())
+        ]
+        try:
+            titles = fetch_conversation_titles(pairs)
+        except Exception:
+            logger.exception(
+                "Failed to resolve titles for AI conversations",
+                extra={"project_ids": sorted({project_id for _, project_id in pairs})},
+            )
+            return
+
+        for conv_id, title in titles.items():
+            if conv_id in conversations_map:
+                conversations_map[conv_id]["title"] = title
diff --git a/tests/sentry/ai_monitoring/test_utils.py b/tests/sentry/ai_monitoring/test_utils.py
index 0d75ecff4b39..11d61da4899a 100644
--- a/tests/sentry/ai_monitoring/test_utils.py
+++ b/tests/sentry/ai_monitoring/test_utils.py
@@ -17,7 +17,7 @@ def test_returns_title_for_requested_pair(self) -> None:
 
         titles = fetch_conversation_titles([("conv-1", self.project.id)])
 
-        assert titles == {("conv-1", self.project.id): "Reset my password"}
+        assert titles == {"conv-1": "Reset my password"}
 
     def test_skips_untitled_rows(self) -> None:
         self.create_ai_conversation_metadata(
@@ -63,32 +63,80 @@ def test_does_not_return_pairs_that_were_not_requested(self) -> None:
         )
 
         assert titles == {
-            ("conv-1", self.project.id): "Owned by project one",
-            ("conv-2", other_project.id): "Second conversation",
+            "conv-1": "Owned by project one",
+            "conv-2": "Second conversation",
         }
 
-    def test_returns_both_projects_when_both_requested(self) -> None:
+    def test_earliest_source_timestamp_wins(self) -> None:
         other_project = self.create_project(organization=self.organization)
+        self.create_ai_conversation_metadata(
+            project=self.project,
+            conversation_id="conv-1",
+            title="Later half of the conversation",
+            title_source_timestamp=datetime(2024, 5, 1, 12, 0, tzinfo=UTC),
+        )
+        self.create_ai_conversation_metadata(
+            project=other_project,
+            conversation_id="conv-1",
+            title="Start of the conversation",
+            title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
+        )
 
+        titles = fetch_conversation_titles(
+            [("conv-1", self.project.id), ("conv-1", other_project.id)]
+        )
+
+        assert titles == {"conv-1": "Start of the conversation"}
+
+    def test_null_source_timestamp_loses(self) -> None:
+        other_project = self.create_project(organization=self.organization)
         self.create_ai_conversation_metadata(
             project=self.project,
             conversation_id="conv-1",
-            title="Owned by project one",
+            title="Unknown when this started",
+            title_source_timestamp=None,
         )
         self.create_ai_conversation_metadata(
             project=other_project,
             conversation_id="conv-1",
-            title="Owned by project two",
+            title="Start of the conversation",
+            title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
         )
 
         titles = fetch_conversation_titles(
             [("conv-1", self.project.id), ("conv-1", other_project.id)]
         )
 
-        assert titles == {
-            ("conv-1", self.project.id): "Owned by project one",
-            ("conv-1", other_project.id): "Owned by project two",
-        }
+        assert titles == {"conv-1": "Start of the conversation"}
+
+    def test_ties_break_on_project_id(self) -> None:
+        source_timestamp = datetime(2024, 5, 1, tzinfo=UTC)
+        lower_project, higher_project = sorted(
+            (
+                self.create_project(organization=self.organization),
+                self.create_project(organization=self.organization),
+            ),
+            key=lambda project: project.id,
+        )
+
+        self.create_ai_conversation_metadata(
+            project=lower_project,
+            conversation_id="conv-1",
+            title="Lower project id",
+            title_source_timestamp=source_timestamp,
+        )
+        self.create_ai_conversation_metadata(
+            project=higher_project,
+            conversation_id="conv-1",
+            title="Higher project id",
+            title_source_timestamp=source_timestamp,
+        )
+
+        titles = fetch_conversation_titles(
+            [("conv-1", lower_project.id), ("conv-1", higher_project.id)]
+        )
+
+        assert titles == {"conv-1": "Lower project id"}
 
 
 class FetchConversationTitleTest(TestCase):
diff --git a/tests/sentry/api/endpoints/test_organization_ai_conversations.py b/tests/sentry/api/endpoints/test_organization_ai_conversations.py
index 2362e91af3cc..4f03bd6abe30 100644
--- a/tests/sentry/api/endpoints/test_organization_ai_conversations.py
+++ b/tests/sentry/api/endpoints/test_organization_ai_conversations.py
@@ -1,6 +1,7 @@
 import json  # noqa: S003
 from datetime import timedelta
 from typing import Any
+from unittest.mock import MagicMock, patch
 from uuid import uuid4
 
 from django.urls import reverse
@@ -1527,7 +1528,7 @@ def test_title_not_taken_from_unrelated_project(self) -> None:
         assert response.data[0]["title"] is None
 
     def test_title_for_conversation_spanning_projects(self) -> None:
-        """When a conversation spans projects, the lowest project id with a title wins."""
+        """Equal source timestamps: lowest project id breaks the tie."""
         now = before_now(days=25).replace(microsecond=0)
         conversation_id = uuid4().hex
         lower_project = self.create_project(organization=self.organization)
@@ -1565,6 +1566,45 @@ def test_title_for_conversation_spanning_projects(self) -> None:
         assert len(response.data) == 1
         assert response.data[0]["title"] == "Lower project id title"
 
+    def test_title_earliest_source_timestamp_wins_across_projects(self) -> None:
+        """Across projects, earliest title_source_timestamp wins (not lowest project id)."""
+        now = before_now(days=25).replace(microsecond=0)
+        conversation_id = uuid4().hex
+        lower_project = self.create_project(organization=self.organization)
+        higher_project = self.create_project(organization=self.organization)
+        assert lower_project.id < higher_project.id
+
+        self._store_conversation_span(
+            conversation_id, now - timedelta(seconds=2), project=lower_project
+        )
+        self._store_conversation_span(
+            conversation_id, now - timedelta(seconds=1), project=higher_project
+        )
+
+        self.create_ai_conversation_metadata(
+            project=lower_project,
+            conversation_id=conversation_id,
+            title="Later titled project",
+            title_source_timestamp=now - timedelta(seconds=1),
+        )
+        self.create_ai_conversation_metadata(
+            project=higher_project,
+            conversation_id=conversation_id,
+            title="Earlier titled project",
+            title_source_timestamp=now - timedelta(seconds=2),
+        )
+
+        query = {
+            "project": [lower_project.id, higher_project.id],
+            "start": (now - timedelta(hours=1)).isoformat(),
+            "end": (now + timedelta(hours=1)).isoformat(),
+        }
+
+        response = self.do_request(query)
+        assert response.status_code == 200, response.data
+        assert len(response.data) == 1
+        assert response.data[0]["title"] == "Earlier titled project"
+
     def test_title_found_when_only_higher_project_id_has_one(self) -> None:
         """Every project the conversation spans is searched, not just the lowest."""
         now = before_now(days=25).replace(microsecond=0)
@@ -1597,3 +1637,27 @@ def test_title_found_when_only_higher_project_id_has_one(self) -> None:
         assert response.status_code == 200, response.data
         assert len(response.data) == 1
         assert response.data[0]["title"] == "Higher project id title"
+
+    @patch(
+        "sentry.api.endpoints.organization_ai_conversations.fetch_conversation_titles",
+        side_effect=Exception("metadata unavailable"),
+    )
+    def test_title_lookup_failure_does_not_break_list(
+        self, mock_fetch_conversation_titles: MagicMock
+    ) -> None:
+        now = before_now(days=25).replace(microsecond=0)
+        conversation_id = uuid4().hex
+
+        self._store_conversation_span(conversation_id, now)
+
+        query = {
+            "project": [self.project.id],
+            "start": (now - timedelta(hours=1)).isoformat(),
+            "end": (now + timedelta(hours=1)).isoformat(),
+        }
+
+        response = self.do_request(query)
+        assert response.status_code == 200, response.data
+        assert len(response.data) == 1
+        assert response.data[0]["title"] is None
+        assert mock_fetch_conversation_titles.call_count == 1

From 87c8f813d2b48fc74e6f31be2adfcbc52bc7f14a Mon Sep 17 00:00:00 2001
From: Vjeran Grozdanic <vjeran.grozdanic@sentry.io>
Date: Mon, 3 Aug 2026 14:53:41 +0200
Subject: [PATCH 2/4] ref(ai-monitoring): Keep conversation titles keyed by
 project

Conversation ids are only unique within a project, so bulk title lookup
returns per (conversation_id, project_id) again. List still picks a
stable display title and survives metadata lookup failures.
---
 src/sentry/ai_monitoring/utils.py             | 20 +++---
 .../organization_ai_conversations.py          | 26 +++++--
 tests/sentry/ai_monitoring/test_utils.py      | 68 +++----------------
 .../test_organization_ai_conversations.py     | 41 +----------
 4 files changed, 41 insertions(+), 114 deletions(-)

diff --git a/src/sentry/ai_monitoring/utils.py b/src/sentry/ai_monitoring/utils.py
index c8e2c5c17095..d51083db5079 100644
--- a/src/sentry/ai_monitoring/utils.py
+++ b/src/sentry/ai_monitoring/utils.py
@@ -116,11 +116,11 @@ def fetch_conversation_title(
 
 def fetch_conversation_titles(
     conversation_project_pairs: Collection[tuple[str, int]],
-) -> dict[str, str]:
-    """One winning title per conversation_id among the given pairs.
+) -> dict[tuple[str, int], str]:
+    """Look up stored titles for the given (conversation_id, project_id) pairs.
 
-    Same selection as ``fetch_conversation_title``. Only requested pairs participate;
-    untitled conversations are absent from the result.
+    A conversation id is only unique within a project, so callers must key on the
+    pair. Pairs without a titled row are simply absent from the result.
     """
     if not conversation_project_pairs:
         return {}
@@ -138,16 +138,16 @@ def fetch_conversation_titles(
             title__isnull=False,
         )
         .exclude(title="")
-        .order_by(*TITLE_ORDER_BY)
         .values_list("conversation_id_hash", "project_id", "title")
     )
 
-    # Filter is hashes × projects; drop unrequested pairs. Order makes setdefault win.
-    titles: dict[str, str] = {}
+    # The filter matches the cross product of the hashes and the projects, so drop
+    # any (conversation, project) combination the caller did not ask about.
+    titles: dict[tuple[str, int], str] = {}
     for row_hash, project_id, title in rows:
-        conversation_id = conversation_id_by_hash[row_hash]
-        if (conversation_id, project_id) in requested_pairs:
-            titles.setdefault(conversation_id, title)
+        pair = (conversation_id_by_hash[row_hash], project_id)
+        if pair in requested_pairs:
+            titles[pair] = title
 
     return titles
 
diff --git a/src/sentry/api/endpoints/organization_ai_conversations.py b/src/sentry/api/endpoints/organization_ai_conversations.py
index 2d170ca039e0..9e7920651eb9 100644
--- a/src/sentry/api/endpoints/organization_ai_conversations.py
+++ b/src/sentry/api/endpoints/organization_ai_conversations.py
@@ -1,7 +1,7 @@
 import logging
 import re
 from collections import defaultdict
-from collections.abc import Mapping
+from collections.abc import Mapping, Sequence
 from datetime import datetime
 from typing import Any, TypedDict
 
@@ -80,6 +80,17 @@ def _compute_timestamp_ms(finish_ts: float) -> int:
     return int(finish_ts * 1000) if finish_ts else 0
 
 
+def _first_title(
+    titles: Mapping[tuple[str, int], str], conv_id: str, project_ids: Sequence[int]
+) -> str | None:
+    """Lowest project id with a stored title wins, so results are stable across requests."""
+    for project_id in project_ids:
+        title = titles.get((conv_id, project_id))
+        if title is not None:
+            return title
+    return None
+
+
 def _extract_first_user_message(messages: Any) -> str | None:
     """Extract first user message, handling both old (content) and new (parts) formats."""
     if isinstance(messages, str) and messages == FILTERED:
@@ -585,10 +596,14 @@ def _apply_titles(
 
         On lookup failure, log and leave titles unset so the list response still succeeds.
         """
+        sorted_project_ids = {
+            conv_id: sorted(project_ids_by_conversation.get(conv_id, ()))
+            for conv_id in conversations_map
+        }
         pairs = [
             (conv_id, project_id)
-            for conv_id in conversations_map
-            for project_id in project_ids_by_conversation.get(conv_id, ())
+            for conv_id, project_ids in sorted_project_ids.items()
+            for project_id in project_ids
         ]
         try:
             titles = fetch_conversation_titles(pairs)
@@ -599,6 +614,5 @@ def _apply_titles(
             )
             return
 
-        for conv_id, title in titles.items():
-            if conv_id in conversations_map:
-                conversations_map[conv_id]["title"] = title
+        for conv_id, conversation in conversations_map.items():
+            conversation["title"] = _first_title(titles, conv_id, sorted_project_ids[conv_id])
diff --git a/tests/sentry/ai_monitoring/test_utils.py b/tests/sentry/ai_monitoring/test_utils.py
index 11d61da4899a..0d75ecff4b39 100644
--- a/tests/sentry/ai_monitoring/test_utils.py
+++ b/tests/sentry/ai_monitoring/test_utils.py
@@ -17,7 +17,7 @@ def test_returns_title_for_requested_pair(self) -> None:
 
         titles = fetch_conversation_titles([("conv-1", self.project.id)])
 
-        assert titles == {"conv-1": "Reset my password"}
+        assert titles == {("conv-1", self.project.id): "Reset my password"}
 
     def test_skips_untitled_rows(self) -> None:
         self.create_ai_conversation_metadata(
@@ -63,80 +63,32 @@ def test_does_not_return_pairs_that_were_not_requested(self) -> None:
         )
 
         assert titles == {
-            "conv-1": "Owned by project one",
-            "conv-2": "Second conversation",
+            ("conv-1", self.project.id): "Owned by project one",
+            ("conv-2", other_project.id): "Second conversation",
         }
 
-    def test_earliest_source_timestamp_wins(self) -> None:
+    def test_returns_both_projects_when_both_requested(self) -> None:
         other_project = self.create_project(organization=self.organization)
-        self.create_ai_conversation_metadata(
-            project=self.project,
-            conversation_id="conv-1",
-            title="Later half of the conversation",
-            title_source_timestamp=datetime(2024, 5, 1, 12, 0, tzinfo=UTC),
-        )
-        self.create_ai_conversation_metadata(
-            project=other_project,
-            conversation_id="conv-1",
-            title="Start of the conversation",
-            title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
-        )
 
-        titles = fetch_conversation_titles(
-            [("conv-1", self.project.id), ("conv-1", other_project.id)]
-        )
-
-        assert titles == {"conv-1": "Start of the conversation"}
-
-    def test_null_source_timestamp_loses(self) -> None:
-        other_project = self.create_project(organization=self.organization)
         self.create_ai_conversation_metadata(
             project=self.project,
             conversation_id="conv-1",
-            title="Unknown when this started",
-            title_source_timestamp=None,
+            title="Owned by project one",
         )
         self.create_ai_conversation_metadata(
             project=other_project,
             conversation_id="conv-1",
-            title="Start of the conversation",
-            title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
+            title="Owned by project two",
         )
 
         titles = fetch_conversation_titles(
             [("conv-1", self.project.id), ("conv-1", other_project.id)]
         )
 
-        assert titles == {"conv-1": "Start of the conversation"}
-
-    def test_ties_break_on_project_id(self) -> None:
-        source_timestamp = datetime(2024, 5, 1, tzinfo=UTC)
-        lower_project, higher_project = sorted(
-            (
-                self.create_project(organization=self.organization),
-                self.create_project(organization=self.organization),
-            ),
-            key=lambda project: project.id,
-        )
-
-        self.create_ai_conversation_metadata(
-            project=lower_project,
-            conversation_id="conv-1",
-            title="Lower project id",
-            title_source_timestamp=source_timestamp,
-        )
-        self.create_ai_conversation_metadata(
-            project=higher_project,
-            conversation_id="conv-1",
-            title="Higher project id",
-            title_source_timestamp=source_timestamp,
-        )
-
-        titles = fetch_conversation_titles(
-            [("conv-1", lower_project.id), ("conv-1", higher_project.id)]
-        )
-
-        assert titles == {"conv-1": "Lower project id"}
+        assert titles == {
+            ("conv-1", self.project.id): "Owned by project one",
+            ("conv-1", other_project.id): "Owned by project two",
+        }
 
 
 class FetchConversationTitleTest(TestCase):
diff --git a/tests/sentry/api/endpoints/test_organization_ai_conversations.py b/tests/sentry/api/endpoints/test_organization_ai_conversations.py
index 4f03bd6abe30..0d83d7bdf4c9 100644
--- a/tests/sentry/api/endpoints/test_organization_ai_conversations.py
+++ b/tests/sentry/api/endpoints/test_organization_ai_conversations.py
@@ -1528,7 +1528,7 @@ def test_title_not_taken_from_unrelated_project(self) -> None:
         assert response.data[0]["title"] is None
 
     def test_title_for_conversation_spanning_projects(self) -> None:
-        """Equal source timestamps: lowest project id breaks the tie."""
+        """When a conversation spans projects, the lowest project id with a title wins."""
         now = before_now(days=25).replace(microsecond=0)
         conversation_id = uuid4().hex
         lower_project = self.create_project(organization=self.organization)
@@ -1566,45 +1566,6 @@ def test_title_for_conversation_spanning_projects(self) -> None:
         assert len(response.data) == 1
         assert response.data[0]["title"] == "Lower project id title"
 
-    def test_title_earliest_source_timestamp_wins_across_projects(self) -> None:
-        """Across projects, earliest title_source_timestamp wins (not lowest project id)."""
-        now = before_now(days=25).replace(microsecond=0)
-        conversation_id = uuid4().hex
-        lower_project = self.create_project(organization=self.organization)
-        higher_project = self.create_project(organization=self.organization)
-        assert lower_project.id < higher_project.id
-
-        self._store_conversation_span(
-            conversation_id, now - timedelta(seconds=2), project=lower_project
-        )
-        self._store_conversation_span(
-            conversation_id, now - timedelta(seconds=1), project=higher_project
-        )
-
-        self.create_ai_conversation_metadata(
-            project=lower_project,
-            conversation_id=conversation_id,
-            title="Later titled project",
-            title_source_timestamp=now - timedelta(seconds=1),
-        )
-        self.create_ai_conversation_metadata(
-            project=higher_project,
-            conversation_id=conversation_id,
-            title="Earlier titled project",
-            title_source_timestamp=now - timedelta(seconds=2),
-        )
-
-        query = {
-            "project": [lower_project.id, higher_project.id],
-            "start": (now - timedelta(hours=1)).isoformat(),
-            "end": (now + timedelta(hours=1)).isoformat(),
-        }
-
-        response = self.do_request(query)
-        assert response.status_code == 200, response.data
-        assert len(response.data) == 1
-        assert response.data[0]["title"] == "Earlier titled project"
-
     def test_title_found_when_only_higher_project_id_has_one(self) -> None:
         """Every project the conversation spans is searched, not just the lowest."""
         now = before_now(days=25).replace(microsecond=0)

From 394a20677289011198a20e967c202fa2204e20b6 Mon Sep 17 00:00:00 2001
From: Vjeran Grozdanic <vjeran.grozdanic@sentry.io>
Date: Mon, 3 Aug 2026 22:28:56 +0200
Subject: [PATCH 3/4] ref(ai-monitoring): Simplify list conversation title
 lookup

Bulk titles are keyed by conversation_id over the request project scope,
using the same earliest-source selection as detail. Drop pair maps and
endpoint-side title picking; list lookup failures stay non-fatal.
---
 src/sentry/ai_monitoring/utils.py             |  71 ++++++------
 .../organization_ai_conversations.py          |  51 +++------
 tests/sentry/ai_monitoring/test_utils.py      | 102 ++++++++++++------
 .../test_organization_ai_conversations.py     |  41 ++++++-
 4 files changed, 157 insertions(+), 108 deletions(-)

diff --git a/src/sentry/ai_monitoring/utils.py b/src/sentry/ai_monitoring/utils.py
index d51083db5079..e94d0307c153 100644
--- a/src/sentry/ai_monitoring/utils.py
+++ b/src/sentry/ai_monitoring/utils.py
@@ -88,6 +88,39 @@ def clamp_conversation_id_for_storage(conversation_id: str) -> str:
 TITLE_ORDER_BY = (F("title_source_timestamp").asc(nulls_last=True), "project_id")
 
 
+def fetch_conversation_titles(
+    conversation_ids: Collection[str],
+    project_ids: Collection[int],
+) -> dict[str, str]:
+    """One title per conversation_id among the given projects.
+
+    Earliest ``title_source_timestamp`` wins; ``project_id`` breaks ties.
+    """
+    if not conversation_ids or not project_ids:
+        return {}
+
+    conversation_id_by_hash = {
+        conversation_id_hash(conversation_id): conversation_id
+        for conversation_id in conversation_ids
+    }
+
+    rows = (
+        AIConversationMetadata.objects.filter(
+            project_id__in=set(project_ids),
+            conversation_id_hash__in=conversation_id_by_hash,
+            title__isnull=False,
+        )
+        .exclude(title="")
+        .order_by(*TITLE_ORDER_BY)
+        .values_list("conversation_id_hash", "title")
+    )
+
+    titles: dict[str, str] = {}
+    for row_hash, title in rows:
+        titles.setdefault(conversation_id_by_hash[row_hash], title)
+    return titles
+
+
 def fetch_conversation_title(
     conversation_id: str,
     project_ids: Collection[int],
@@ -114,44 +147,6 @@ def fetch_conversation_title(
     )
 
 
-def fetch_conversation_titles(
-    conversation_project_pairs: Collection[tuple[str, int]],
-) -> dict[tuple[str, int], str]:
-    """Look up stored titles for the given (conversation_id, project_id) pairs.
-
-    A conversation id is only unique within a project, so callers must key on the
-    pair. Pairs without a titled row are simply absent from the result.
-    """
-    if not conversation_project_pairs:
-        return {}
-
-    requested_pairs = set(conversation_project_pairs)
-    conversation_id_by_hash = {
-        conversation_id_hash(conversation_id): conversation_id
-        for conversation_id, _ in requested_pairs
-    }
-
-    rows = (
-        AIConversationMetadata.objects.filter(
-            project_id__in={project_id for _, project_id in requested_pairs},
-            conversation_id_hash__in=conversation_id_by_hash,
-            title__isnull=False,
-        )
-        .exclude(title="")
-        .values_list("conversation_id_hash", "project_id", "title")
-    )
-
-    # The filter matches the cross product of the hashes and the projects, so drop
-    # any (conversation, project) combination the caller did not ask about.
-    titles: dict[tuple[str, int], str] = {}
-    for row_hash, project_id, title in rows:
-        pair = (conversation_id_by_hash[row_hash], project_id)
-        if pair in requested_pairs:
-            titles[pair] = title
-
-    return titles
-
-
 def _extract_first_user_message(messages: Any) -> str | None:
     if isinstance(messages, str) and messages == FILTERED:
         return None
diff --git a/src/sentry/api/endpoints/organization_ai_conversations.py b/src/sentry/api/endpoints/organization_ai_conversations.py
index 9e7920651eb9..0a17ecad28b7 100644
--- a/src/sentry/api/endpoints/organization_ai_conversations.py
+++ b/src/sentry/api/endpoints/organization_ai_conversations.py
@@ -1,7 +1,7 @@
 import logging
 import re
 from collections import defaultdict
-from collections.abc import Mapping, Sequence
+from collections.abc import Collection
 from datetime import datetime
 from typing import Any, TypedDict
 
@@ -80,17 +80,6 @@ def _compute_timestamp_ms(finish_ts: float) -> int:
     return int(finish_ts * 1000) if finish_ts else 0
 
 
-def _first_title(
-    titles: Mapping[tuple[str, int], str], conv_id: str, project_ids: Sequence[int]
-) -> str | None:
-    """Lowest project id with a stored title wins, so results are stable across requests."""
-    for project_id in project_ids:
-        title = titles.get((conv_id, project_id))
-        if title is not None:
-            return title
-    return None
-
-
 def _extract_first_user_message(messages: Any) -> str | None:
     """Extract first user message, handling both old (content) and new (parts) formats."""
     if isinstance(messages, str) and messages == FILTERED:
@@ -332,11 +321,9 @@ def _get_conversations_data(self, snuba_params, conversation_ids: list[str]) ->
         # Process results
         with start_span(op="ai_conversations.process", name="Process query results"):
             conversations_map = self._build_conversations_from_aggregations(results["aggregations"])
-            project_ids_by_conversation = self._apply_enrichment(
-                conversations_map, results["enrichment"]
-            )
+            self._apply_enrichment(conversations_map, results["enrichment"])
             self._apply_first_last_io(conversations_map, results["first_last_io"])
-            self._apply_titles(conversations_map, project_ids_by_conversation)
+            self._apply_titles(conversations_map, snuba_params.project_ids)
 
         return [
             conversations_map[conv_id]
@@ -479,8 +466,8 @@ def _build_conversations_from_aggregations(
 
     def _apply_enrichment(
         self, conversations_map: dict[str, dict[str, Any]], enrichment_data: EAPResponse
-    ) -> dict[str, set[int]]:
-        """Apply enrichment data, returning the project ids each conversation spans."""
+    ) -> None:
+        """Apply enrichment data from span rows onto each conversation."""
         with start_span(
             op="ai_conversations.apply_enrichment",
             name="Apply enrichment data",
@@ -492,7 +479,6 @@ def _apply_enrichment(
             traces_by_conversation: dict[str, set[str]] = defaultdict(set)
             tool_names_by_conversation: dict[str, set[str]] = defaultdict(set)
             tool_errors_by_conversation: dict[str, int] = defaultdict(int)
-            project_ids_by_conversation: dict[str, set[int]] = defaultdict(set)
             # Rows are sorted by timestamp, so the first occurrence per conversation
             # is the earliest span. Track the first span's user and project.
             user_by_conversation: dict[str, UserResponse] = {}
@@ -504,10 +490,8 @@ def _apply_enrichment(
                     continue
 
                 project_id = row.get("project.id")
-                if isinstance(project_id, int):
-                    project_ids_by_conversation[conv_id].add(project_id)
-                    if conv_id not in first_project_by_conversation:
-                        first_project_by_conversation[conv_id] = project_id
+                if isinstance(project_id, int) and conv_id not in first_project_by_conversation:
+                    first_project_by_conversation[conv_id] = project_id
 
                 trace_id = row.get("trace", "")
                 if trace_id:
@@ -547,8 +531,6 @@ def _apply_enrichment(
                 conversation["toolErrors"] = tool_errors_by_conversation.get(conv_id, 0)
                 conversation["projectId"] = first_project_by_conversation.get(conv_id)
 
-            return project_ids_by_conversation
-
     def _apply_first_last_io(
         self, conversations_map: dict[str, dict[str, Any]], first_last_io_data: EAPResponse
     ) -> None:
@@ -590,29 +572,20 @@ def _apply_first_last_io(
     def _apply_titles(
         self,
         conversations_map: dict[str, dict[str, Any]],
-        project_ids_by_conversation: Mapping[str, set[int]],
+        project_ids: Collection[int],
     ) -> None:
         """Set each conversation's `title` from storage when present.
 
         On lookup failure, log and leave titles unset so the list response still succeeds.
         """
-        sorted_project_ids = {
-            conv_id: sorted(project_ids_by_conversation.get(conv_id, ()))
-            for conv_id in conversations_map
-        }
-        pairs = [
-            (conv_id, project_id)
-            for conv_id, project_ids in sorted_project_ids.items()
-            for project_id in project_ids
-        ]
         try:
-            titles = fetch_conversation_titles(pairs)
+            titles = fetch_conversation_titles(conversations_map.keys(), project_ids)
         except Exception:
             logger.exception(
                 "Failed to resolve titles for AI conversations",
-                extra={"project_ids": sorted({project_id for _, project_id in pairs})},
+                extra={"project_ids": sorted(project_ids)},
             )
             return
 
-        for conv_id, conversation in conversations_map.items():
-            conversation["title"] = _first_title(titles, conv_id, sorted_project_ids[conv_id])
+        for conv_id, title in titles.items():
+            conversations_map[conv_id]["title"] = title
diff --git a/tests/sentry/ai_monitoring/test_utils.py b/tests/sentry/ai_monitoring/test_utils.py
index 0d75ecff4b39..5e3ad61b9cd5 100644
--- a/tests/sentry/ai_monitoring/test_utils.py
+++ b/tests/sentry/ai_monitoring/test_utils.py
@@ -5,19 +5,20 @@
 
 
 class FetchConversationTitlesTest(TestCase):
-    def test_returns_empty_for_no_pairs(self) -> None:
-        assert fetch_conversation_titles([]) == {}
+    def test_returns_empty_without_ids_or_projects(self) -> None:
+        assert fetch_conversation_titles([], [self.project.id]) == {}
+        assert fetch_conversation_titles(["conv-1"], []) == {}
 
-    def test_returns_title_for_requested_pair(self) -> None:
+    def test_returns_title_for_requested_conversation(self) -> None:
         self.create_ai_conversation_metadata(
             project=self.project,
             conversation_id="conv-1",
             title="Reset my password",
         )
 
-        titles = fetch_conversation_titles([("conv-1", self.project.id)])
+        titles = fetch_conversation_titles(["conv-1"], [self.project.id])
 
-        assert titles == {("conv-1", self.project.id): "Reset my password"}
+        assert titles == {"conv-1": "Reset my password"}
 
     def test_skips_untitled_rows(self) -> None:
         self.create_ai_conversation_metadata(
@@ -26,7 +27,7 @@ def test_skips_untitled_rows(self) -> None:
             title=None,
         )
 
-        assert fetch_conversation_titles([("conv-1", self.project.id)]) == {}
+        assert fetch_conversation_titles(["conv-1"], [self.project.id]) == {}
 
     def test_skips_unknown_conversations(self) -> None:
         self.create_ai_conversation_metadata(
@@ -35,60 +36,101 @@ def test_skips_unknown_conversations(self) -> None:
             title="Reset my password",
         )
 
-        assert fetch_conversation_titles([("conv-2", self.project.id)]) == {}
+        assert fetch_conversation_titles(["conv-2"], [self.project.id]) == {}
 
-    def test_does_not_return_pairs_that_were_not_requested(self) -> None:
-        """A row matching the queried hashes and projects, but not as a requested pair."""
+    def test_ignores_projects_outside_scope(self) -> None:
         other_project = self.create_project(organization=self.organization)
+        self.create_ai_conversation_metadata(
+            project=other_project,
+            conversation_id="conv-1",
+            title="Owned by project two",
+        )
+
+        assert fetch_conversation_titles(["conv-1"], [self.project.id]) == {}
 
+    def test_earliest_source_timestamp_wins(self) -> None:
+        other_project = self.create_project(organization=self.organization)
         self.create_ai_conversation_metadata(
             project=self.project,
             conversation_id="conv-1",
-            title="Owned by project one",
+            title="Later half of the conversation",
+            title_source_timestamp=datetime(2024, 5, 1, 12, 0, tzinfo=UTC),
         )
         self.create_ai_conversation_metadata(
             project=other_project,
             conversation_id="conv-1",
-            title="Owned by project two",
+            title="Start of the conversation",
+            title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
+        )
+
+        titles = fetch_conversation_titles(["conv-1"], [self.project.id, other_project.id])
+
+        assert titles == {"conv-1": "Start of the conversation"}
+
+    def test_null_source_timestamp_loses(self) -> None:
+        other_project = self.create_project(organization=self.organization)
+        self.create_ai_conversation_metadata(
+            project=self.project,
+            conversation_id="conv-1",
+            title="Unknown when this started",
+            title_source_timestamp=None,
         )
         self.create_ai_conversation_metadata(
             project=other_project,
-            conversation_id="conv-2",
-            title="Second conversation",
+            conversation_id="conv-1",
+            title="Start of the conversation",
+            title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
         )
 
-        # conv-1 is only asked about for self.project, conv-2 only for other_project.
-        titles = fetch_conversation_titles(
-            [("conv-1", self.project.id), ("conv-2", other_project.id)]
+        titles = fetch_conversation_titles(["conv-1"], [self.project.id, other_project.id])
+
+        assert titles == {"conv-1": "Start of the conversation"}
+
+    def test_ties_break_on_project_id(self) -> None:
+        source_timestamp = datetime(2024, 5, 1, tzinfo=UTC)
+        lower_project, higher_project = sorted(
+            (
+                self.create_project(organization=self.organization),
+                self.create_project(organization=self.organization),
+            ),
+            key=lambda project: project.id,
+        )
+
+        self.create_ai_conversation_metadata(
+            project=lower_project,
+            conversation_id="conv-1",
+            title="Lower project id",
+            title_source_timestamp=source_timestamp,
+        )
+        self.create_ai_conversation_metadata(
+            project=higher_project,
+            conversation_id="conv-1",
+            title="Higher project id",
+            title_source_timestamp=source_timestamp,
         )
 
-        assert titles == {
-            ("conv-1", self.project.id): "Owned by project one",
-            ("conv-2", other_project.id): "Second conversation",
-        }
+        titles = fetch_conversation_titles(["conv-1"], [lower_project.id, higher_project.id])
 
-    def test_returns_both_projects_when_both_requested(self) -> None:
-        other_project = self.create_project(organization=self.organization)
+        assert titles == {"conv-1": "Lower project id"}
 
+    def test_multiple_conversations(self) -> None:
+        other_project = self.create_project(organization=self.organization)
         self.create_ai_conversation_metadata(
             project=self.project,
             conversation_id="conv-1",
-            title="Owned by project one",
+            title="First",
         )
         self.create_ai_conversation_metadata(
             project=other_project,
-            conversation_id="conv-1",
-            title="Owned by project two",
+            conversation_id="conv-2",
+            title="Second",
         )
 
         titles = fetch_conversation_titles(
-            [("conv-1", self.project.id), ("conv-1", other_project.id)]
+            ["conv-1", "conv-2"], [self.project.id, other_project.id]
         )
 
-        assert titles == {
-            ("conv-1", self.project.id): "Owned by project one",
-            ("conv-1", other_project.id): "Owned by project two",
-        }
+        assert titles == {"conv-1": "First", "conv-2": "Second"}
 
 
 class FetchConversationTitleTest(TestCase):
diff --git a/tests/sentry/api/endpoints/test_organization_ai_conversations.py b/tests/sentry/api/endpoints/test_organization_ai_conversations.py
index 0d83d7bdf4c9..4f03bd6abe30 100644
--- a/tests/sentry/api/endpoints/test_organization_ai_conversations.py
+++ b/tests/sentry/api/endpoints/test_organization_ai_conversations.py
@@ -1528,7 +1528,7 @@ def test_title_not_taken_from_unrelated_project(self) -> None:
         assert response.data[0]["title"] is None
 
     def test_title_for_conversation_spanning_projects(self) -> None:
-        """When a conversation spans projects, the lowest project id with a title wins."""
+        """Equal source timestamps: lowest project id breaks the tie."""
         now = before_now(days=25).replace(microsecond=0)
         conversation_id = uuid4().hex
         lower_project = self.create_project(organization=self.organization)
@@ -1566,6 +1566,45 @@ def test_title_for_conversation_spanning_projects(self) -> None:
         assert len(response.data) == 1
         assert response.data[0]["title"] == "Lower project id title"
 
+    def test_title_earliest_source_timestamp_wins_across_projects(self) -> None:
+        """Across projects, earliest title_source_timestamp wins (not lowest project id)."""
+        now = before_now(days=25).replace(microsecond=0)
+        conversation_id = uuid4().hex
+        lower_project = self.create_project(organization=self.organization)
+        higher_project = self.create_project(organization=self.organization)
+        assert lower_project.id < higher_project.id
+
+        self._store_conversation_span(
+            conversation_id, now - timedelta(seconds=2), project=lower_project
+        )
+        self._store_conversation_span(
+            conversation_id, now - timedelta(seconds=1), project=higher_project
+        )
+
+        self.create_ai_conversation_metadata(
+            project=lower_project,
+            conversation_id=conversation_id,
+            title="Later titled project",
+            title_source_timestamp=now - timedelta(seconds=1),
+        )
+        self.create_ai_conversation_metadata(
+            project=higher_project,
+            conversation_id=conversation_id,
+            title="Earlier titled project",
+            title_source_timestamp=now - timedelta(seconds=2),
+        )
+
+        query = {
+            "project": [lower_project.id, higher_project.id],
+            "start": (now - timedelta(hours=1)).isoformat(),
+            "end": (now + timedelta(hours=1)).isoformat(),
+        }
+
+        response = self.do_request(query)
+        assert response.status_code == 200, response.data
+        assert len(response.data) == 1
+        assert response.data[0]["title"] == "Earlier titled project"
+
     def test_title_found_when_only_higher_project_id_has_one(self) -> None:
         """Every project the conversation spans is searched, not just the lowest."""
         now = before_now(days=25).replace(microsecond=0)

From 62e19853bffbd37348d4ef228844f0397fbff7d0 Mon Sep 17 00:00:00 2001
From: Vjeran Grozdanic <vjeran.grozdanic@sentry.io>
Date: Mon, 3 Aug 2026 22:38:25 +0200
Subject: [PATCH 4/4] fix(ai-monitoring): Scope list titles to conversation
 projects

Bulk title lookup only considers (conversation_id, project_id) pairs from
span enrichment, so a same id in another request project cannot supply the
title. Also fix setdefault typing for nullable title columns.
---
 src/sentry/ai_monitoring/utils.py             | 25 ++++---
 .../organization_ai_conversations.py          | 32 ++++++---
 tests/sentry/ai_monitoring/test_utils.py      | 65 +++++++++++++------
 3 files changed, 82 insertions(+), 40 deletions(-)

diff --git a/src/sentry/ai_monitoring/utils.py b/src/sentry/ai_monitoring/utils.py
index e94d0307c153..db207035ee35 100644
--- a/src/sentry/ai_monitoring/utils.py
+++ b/src/sentry/ai_monitoring/utils.py
@@ -89,35 +89,40 @@ def clamp_conversation_id_for_storage(conversation_id: str) -> str:
 
 
 def fetch_conversation_titles(
-    conversation_ids: Collection[str],
-    project_ids: Collection[int],
+    conversation_project_pairs: Collection[tuple[str, int]],
 ) -> dict[str, str]:
-    """One title per conversation_id among the given projects.
+    """One title per conversation_id among the given (conversation_id, project_id) pairs.
 
-    Earliest ``title_source_timestamp`` wins; ``project_id`` breaks ties.
+    Only requested pairs are considered (ids are unique per project). Among those,
+    earliest ``title_source_timestamp`` wins; ``project_id`` breaks ties.
     """
-    if not conversation_ids or not project_ids:
+    if not conversation_project_pairs:
         return {}
 
+    requested_pairs = set(conversation_project_pairs)
     conversation_id_by_hash = {
         conversation_id_hash(conversation_id): conversation_id
-        for conversation_id in conversation_ids
+        for conversation_id, _ in requested_pairs
     }
 
     rows = (
         AIConversationMetadata.objects.filter(
-            project_id__in=set(project_ids),
+            project_id__in={project_id for _, project_id in requested_pairs},
             conversation_id_hash__in=conversation_id_by_hash,
             title__isnull=False,
         )
         .exclude(title="")
         .order_by(*TITLE_ORDER_BY)
-        .values_list("conversation_id_hash", "title")
+        .values_list("conversation_id_hash", "project_id", "title")
     )
 
     titles: dict[str, str] = {}
-    for row_hash, title in rows:
-        titles.setdefault(conversation_id_by_hash[row_hash], title)
+    for row_hash, project_id, title in rows:
+        if title is None:
+            continue
+        conversation_id = conversation_id_by_hash[row_hash]
+        if (conversation_id, project_id) in requested_pairs:
+            titles.setdefault(conversation_id, title)
     return titles
 
 
diff --git a/src/sentry/api/endpoints/organization_ai_conversations.py b/src/sentry/api/endpoints/organization_ai_conversations.py
index 0a17ecad28b7..5ade3bd71f82 100644
--- a/src/sentry/api/endpoints/organization_ai_conversations.py
+++ b/src/sentry/api/endpoints/organization_ai_conversations.py
@@ -1,7 +1,7 @@
 import logging
 import re
 from collections import defaultdict
-from collections.abc import Collection
+from collections.abc import Mapping
 from datetime import datetime
 from typing import Any, TypedDict
 
@@ -321,9 +321,11 @@ def _get_conversations_data(self, snuba_params, conversation_ids: list[str]) ->
         # Process results
         with start_span(op="ai_conversations.process", name="Process query results"):
             conversations_map = self._build_conversations_from_aggregations(results["aggregations"])
-            self._apply_enrichment(conversations_map, results["enrichment"])
+            project_ids_by_conversation = self._apply_enrichment(
+                conversations_map, results["enrichment"]
+            )
             self._apply_first_last_io(conversations_map, results["first_last_io"])
-            self._apply_titles(conversations_map, snuba_params.project_ids)
+            self._apply_titles(conversations_map, project_ids_by_conversation)
 
         return [
             conversations_map[conv_id]
@@ -466,8 +468,8 @@ def _build_conversations_from_aggregations(
 
     def _apply_enrichment(
         self, conversations_map: dict[str, dict[str, Any]], enrichment_data: EAPResponse
-    ) -> None:
-        """Apply enrichment data from span rows onto each conversation."""
+    ) -> dict[str, set[int]]:
+        """Apply enrichment data, returning the project ids each conversation spans."""
         with start_span(
             op="ai_conversations.apply_enrichment",
             name="Apply enrichment data",
@@ -479,6 +481,7 @@ def _apply_enrichment(
             traces_by_conversation: dict[str, set[str]] = defaultdict(set)
             tool_names_by_conversation: dict[str, set[str]] = defaultdict(set)
             tool_errors_by_conversation: dict[str, int] = defaultdict(int)
+            project_ids_by_conversation: dict[str, set[int]] = defaultdict(set)
             # Rows are sorted by timestamp, so the first occurrence per conversation
             # is the earliest span. Track the first span's user and project.
             user_by_conversation: dict[str, UserResponse] = {}
@@ -490,8 +493,10 @@ def _apply_enrichment(
                     continue
 
                 project_id = row.get("project.id")
-                if isinstance(project_id, int) and conv_id not in first_project_by_conversation:
-                    first_project_by_conversation[conv_id] = project_id
+                if isinstance(project_id, int):
+                    project_ids_by_conversation[conv_id].add(project_id)
+                    if conv_id not in first_project_by_conversation:
+                        first_project_by_conversation[conv_id] = project_id
 
                 trace_id = row.get("trace", "")
                 if trace_id:
@@ -531,6 +536,8 @@ def _apply_enrichment(
                 conversation["toolErrors"] = tool_errors_by_conversation.get(conv_id, 0)
                 conversation["projectId"] = first_project_by_conversation.get(conv_id)
 
+            return project_ids_by_conversation
+
     def _apply_first_last_io(
         self, conversations_map: dict[str, dict[str, Any]], first_last_io_data: EAPResponse
     ) -> None:
@@ -572,18 +579,23 @@ def _apply_first_last_io(
     def _apply_titles(
         self,
         conversations_map: dict[str, dict[str, Any]],
-        project_ids: Collection[int],
+        project_ids_by_conversation: Mapping[str, set[int]],
     ) -> None:
         """Set each conversation's `title` from storage when present.
 
         On lookup failure, log and leave titles unset so the list response still succeeds.
         """
+        pairs = [
+            (conv_id, project_id)
+            for conv_id in conversations_map
+            for project_id in project_ids_by_conversation.get(conv_id, ())
+        ]
         try:
-            titles = fetch_conversation_titles(conversations_map.keys(), project_ids)
+            titles = fetch_conversation_titles(pairs)
         except Exception:
             logger.exception(
                 "Failed to resolve titles for AI conversations",
-                extra={"project_ids": sorted(project_ids)},
+                extra={"project_ids": sorted({project_id for _, project_id in pairs})},
             )
             return
 
diff --git a/tests/sentry/ai_monitoring/test_utils.py b/tests/sentry/ai_monitoring/test_utils.py
index 5e3ad61b9cd5..92b2ba3acda3 100644
--- a/tests/sentry/ai_monitoring/test_utils.py
+++ b/tests/sentry/ai_monitoring/test_utils.py
@@ -5,18 +5,17 @@
 
 
 class FetchConversationTitlesTest(TestCase):
-    def test_returns_empty_without_ids_or_projects(self) -> None:
-        assert fetch_conversation_titles([], [self.project.id]) == {}
-        assert fetch_conversation_titles(["conv-1"], []) == {}
+    def test_returns_empty_for_no_pairs(self) -> None:
+        assert fetch_conversation_titles([]) == {}
 
-    def test_returns_title_for_requested_conversation(self) -> None:
+    def test_returns_title_for_requested_pair(self) -> None:
         self.create_ai_conversation_metadata(
             project=self.project,
             conversation_id="conv-1",
             title="Reset my password",
         )
 
-        titles = fetch_conversation_titles(["conv-1"], [self.project.id])
+        titles = fetch_conversation_titles([("conv-1", self.project.id)])
 
         assert titles == {"conv-1": "Reset my password"}
 
@@ -27,7 +26,7 @@ def test_skips_untitled_rows(self) -> None:
             title=None,
         )
 
-        assert fetch_conversation_titles(["conv-1"], [self.project.id]) == {}
+        assert fetch_conversation_titles([("conv-1", self.project.id)]) == {}
 
     def test_skips_unknown_conversations(self) -> None:
         self.create_ai_conversation_metadata(
@@ -36,17 +35,37 @@ def test_skips_unknown_conversations(self) -> None:
             title="Reset my password",
         )
 
-        assert fetch_conversation_titles(["conv-2"], [self.project.id]) == {}
+        assert fetch_conversation_titles([("conv-2", self.project.id)]) == {}
 
-    def test_ignores_projects_outside_scope(self) -> None:
+    def test_does_not_return_pairs_that_were_not_requested(self) -> None:
+        """A row matching the queried hashes and projects, but not as a requested pair."""
         other_project = self.create_project(organization=self.organization)
+
+        self.create_ai_conversation_metadata(
+            project=self.project,
+            conversation_id="conv-1",
+            title="Owned by project one",
+        )
         self.create_ai_conversation_metadata(
             project=other_project,
             conversation_id="conv-1",
             title="Owned by project two",
         )
+        self.create_ai_conversation_metadata(
+            project=other_project,
+            conversation_id="conv-2",
+            title="Second conversation",
+        )
+
+        # conv-1 is only asked about for self.project, conv-2 only for other_project.
+        titles = fetch_conversation_titles(
+            [("conv-1", self.project.id), ("conv-2", other_project.id)]
+        )
 
-        assert fetch_conversation_titles(["conv-1"], [self.project.id]) == {}
+        assert titles == {
+            "conv-1": "Owned by project one",
+            "conv-2": "Second conversation",
+        }
 
     def test_earliest_source_timestamp_wins(self) -> None:
         other_project = self.create_project(organization=self.organization)
@@ -63,7 +82,9 @@ def test_earliest_source_timestamp_wins(self) -> None:
             title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
         )
 
-        titles = fetch_conversation_titles(["conv-1"], [self.project.id, other_project.id])
+        titles = fetch_conversation_titles(
+            [("conv-1", self.project.id), ("conv-1", other_project.id)]
+        )
 
         assert titles == {"conv-1": "Start of the conversation"}
 
@@ -82,7 +103,9 @@ def test_null_source_timestamp_loses(self) -> None:
             title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
         )
 
-        titles = fetch_conversation_titles(["conv-1"], [self.project.id, other_project.id])
+        titles = fetch_conversation_titles(
+            [("conv-1", self.project.id), ("conv-1", other_project.id)]
+        )
 
         assert titles == {"conv-1": "Start of the conversation"}
 
@@ -109,28 +132,30 @@ def test_ties_break_on_project_id(self) -> None:
             title_source_timestamp=source_timestamp,
         )
 
-        titles = fetch_conversation_titles(["conv-1"], [lower_project.id, higher_project.id])
+        titles = fetch_conversation_titles(
+            [("conv-1", lower_project.id), ("conv-1", higher_project.id)]
+        )
 
         assert titles == {"conv-1": "Lower project id"}
 
-    def test_multiple_conversations(self) -> None:
+    def test_unrequested_earlier_title_does_not_win(self) -> None:
         other_project = self.create_project(organization=self.organization)
         self.create_ai_conversation_metadata(
             project=self.project,
             conversation_id="conv-1",
-            title="First",
+            title="Requested project title",
+            title_source_timestamp=datetime(2024, 5, 1, 12, 0, tzinfo=UTC),
         )
         self.create_ai_conversation_metadata(
             project=other_project,
-            conversation_id="conv-2",
-            title="Second",
+            conversation_id="conv-1",
+            title="Earlier but unrequested",
+            title_source_timestamp=datetime(2024, 5, 1, 11, 0, tzinfo=UTC),
         )
 
-        titles = fetch_conversation_titles(
-            ["conv-1", "conv-2"], [self.project.id, other_project.id]
-        )
+        titles = fetch_conversation_titles([("conv-1", self.project.id)])
 
-        assert titles == {"conv-1": "First", "conv-2": "Second"}
+        assert titles == {"conv-1": "Requested project title"}
 
 
 class FetchConversationTitleTest(TestCase):