feat(sessions): carry changed session_id in session-list-changed events (#4221) (#4233)

* fix(sessions): include target session in session events

* chore(release): stamp v0.51.430 (Release OQ) for #4221

---------

Co-authored-by: Dennis Soong <dso2ng@gmail.com>
Co-authored-by: nesquena-hermes <agent@nesquena-hermes>

CHANGELOG.md

@@ -3,6 +3,12 @@
 
 ## [Unreleased]
 
+## [v0.51.430] — 2026-06-15 — Release OQ (session-list-changed events carry the changed session id)
+
+### Changed
+
+- **Session-list invalidation events can now carry the specific `session_id` that changed.** `publish_session_list_changed(...)` and the `/api/sessions/events` SSE payload gained an optional `session_id` (defaulting to none, so the broad-refresh behavior is unchanged and backward-compatible). The frontend uses it to tell whether an event targets the currently-open session, refining the refresh signal instead of always doing a broad sidebar refresh. Profile scoping and the legacy one-argument publish shape are preserved. (#4221)
+
 ## [v0.51.429] — 2026-06-15 — Release OP (preserve multiple messageful imported/CLI sessions in the sidebar)
 
 ### Fixed

api/routes.py

@@ -43,17 +43,28 @@ from api.session_events import (
 logger = logging.getLogger(__name__)
 
 
-def _publish_session_list_changed(reason: str, *, profile: str | None = None) -> None:
-    """Publish profile-scoped session changes while tolerating legacy test doubles."""
-    if not profile:
+def _publish_session_list_changed(
+    reason: str,
+    *,
+    profile: str | None = None,
+    session_id: str | None = None,
+) -> None:
+    """Publish scoped session changes while tolerating legacy test doubles."""
+    if not profile and not session_id:
         publish_session_list_changed(reason)
         return
     try:
-        publish_session_list_changed(reason, profile=profile)
+        publish_session_list_changed(reason, profile=profile, session_id=session_id)
     except TypeError:
         # Some focused tests monkeypatch the route-level publisher with the
-        # historical one-argument shape. Preserve the old signal instead of
+        # historical one-argument or profile-only shape. Preserve the old signal instead of
         # turning unrelated session mutations into 500s.
+        if profile:
+            try:
+                publish_session_list_changed(reason, profile=profile)
+                return
+            except TypeError:
+                pass
         publish_session_list_changed(reason)
 
 
@@ -126,7 +137,11 @@ def _persist_generated_session_title(
             while len(SESSIONS) > SESSIONS_MAX:
                 SESSIONS.popitem(last=False)
     _sync_session_title_to_insights(session)
-    _publish_session_list_changed(event_reason, profile=getattr(session, "profile", None))
+    _publish_session_list_changed(
+        event_reason,
+        profile=getattr(session, "profile", None),
+        session_id=sid,
+    )
     if original_session is not session:
         original_session.title = session.title
         original_session.llm_title_generated = session.llm_title_generated
@@ -8005,7 +8020,11 @@ def handle_post(handler, parsed) -> bool:
             worktree_info=worktree_info,
         )
         if worktree_info:
-            publish_session_list_changed("session_new", profile=getattr(s, "profile", None))
+            publish_session_list_changed(
+                "session_new",
+                profile=getattr(s, "profile", None),
+                session_id=getattr(s, "session_id", None),
+            )
         return j(handler, {"session": s.compact() | {"messages": s.messages}})
 
     if parsed.path == "/api/session/duplicate":
@@ -8087,7 +8106,11 @@ def handle_post(handler, parsed) -> bool:
             # Without this explicit save, the duplicate is in-memory only — if the user
             # refreshes before sending a turn, the duplicate vanishes.
             copied_session.save()
-            publish_session_list_changed("session_duplicate", profile=getattr(copied_session, "profile", None))
+            publish_session_list_changed(
+                "session_duplicate",
+                profile=getattr(copied_session, "profile", None),
+                session_id=getattr(copied_session, "session_id", None),
+            )
 
             return j(handler, {"session": copied_session.compact() | {"messages": copied_session.messages}})
         except Exception as e:
@@ -8222,7 +8245,11 @@ def handle_post(handler, parsed) -> bool:
             apply_session_title_rename(s, body["title"])
             s.save()
         _sync_session_title_to_insights(s)
-        publish_session_list_changed("session_rename", profile=getattr(s, "profile", None))
+        publish_session_list_changed(
+            "session_rename",
+            profile=getattr(s, "profile", None),
+            session_id=getattr(s, "session_id", body["session_id"]),
+        )
         return j(handler, {"session": s.compact()})
 
 
@@ -8718,7 +8745,11 @@ def handle_post(handler, parsed) -> bool:
         # Persist only if there are messages (matches new_session pattern)
         if forked_messages:
             branch.save()
-            publish_session_list_changed("session_branch", profile=getattr(branch, "profile", None))
+            publish_session_list_changed(
+                "session_branch",
+                profile=getattr(branch, "profile", None),
+                session_id=getattr(branch, "session_id", None),
+            )
 
         return j(handler, {
             "session_id": branch.session_id,
@@ -9310,7 +9341,11 @@ def handle_post(handler, parsed) -> bool:
             with _get_session_agent_lock(body["session_id"]):
                 s.pinned = pin_requested
                 s.save()
-        publish_session_list_changed("session_pin", profile=getattr(s, "profile", None))
+        publish_session_list_changed(
+            "session_pin",
+            profile=getattr(s, "profile", None),
+            session_id=getattr(s, "session_id", body["session_id"]),
+        )
         return j(handler, {"ok": True, "session": s.compact()})
 
     # ── Session archive (POST) ──
@@ -9387,7 +9422,11 @@ def handle_post(handler, parsed) -> bool:
         with _get_session_agent_lock(sid):
             s.archived = bool(body.get("archived", True))
             s.save(touch_updated_at=False)
-        publish_session_list_changed("session_archive", profile=getattr(s, "profile", None))
+        publish_session_list_changed(
+            "session_archive",
+            profile=getattr(s, "profile", None),
+            session_id=getattr(s, "session_id", sid),
+        )
         return j(handler, {"ok": True, "session": s.compact(), **_worktree_retained_payload(s)})
 
     # ── Session move to project (POST) ──
@@ -9441,7 +9480,11 @@ def handle_post(handler, parsed) -> bool:
             s.save()
         finally:
             _move_lock.release()
-        publish_session_list_changed("session_move", profile=getattr(s, "profile", None))
+        publish_session_list_changed(
+            "session_move",
+            profile=getattr(s, "profile", None),
+            session_id=getattr(s, "session_id", body["session_id"]),
+        )
         return j(handler, {"ok": True, "session": s.compact()})
 
     # ── Project CRUD (POST) ──
@@ -13263,7 +13306,11 @@ def _start_chat_stream_for_session(
                     "_status": 409,
                 }
     if was_hidden_empty_session:
-        publish_session_list_changed("session_new", profile=getattr(s, "profile", None))
+        publish_session_list_changed(
+            "session_new",
+            profile=getattr(s, "profile", None),
+            session_id=getattr(s, "session_id", None),
+        )
     diag.stage("turn_journal_submitted") if diag else None
     journal_event = {}
     try:

api/session_events.py

@@ -31,6 +31,7 @@ def _sessions_changed_payload(
     reason: str,
     version: int,
     profile: str | None = None,
+    session_id: str | None = None,
 ) -> dict:
     payload = {
         "type": "sessions_changed",
@@ -42,6 +43,9 @@ def _sessions_changed_payload(
     # renamed-root alias, and an unscoped refresh preserves the old fail-safe.
     if normalized_profile and not _profile_is_root_alias(normalized_profile):
         payload["profile"] = normalized_profile
+    normalized_session_id = str(session_id or "").strip()
+    if normalized_session_id:
+        payload["session_id"] = normalized_session_id
     return payload
 
 
@@ -51,6 +55,12 @@ def _payload_profile(payload: dict | None) -> str | None:
     return value or None
 
 
+def _payload_session_id(payload: dict | None) -> str | None:
+    value = payload.get("session_id") if isinstance(payload, dict) else None
+    value = str(value or "").strip()
+    return value or None
+
+
 def _coalesced_sessions_changed_payload(pending: dict | None, incoming: dict) -> dict:
     """Merge bounded-queue refresh events without dropping profile-relevant work.
 
@@ -64,15 +74,23 @@ def _coalesced_sessions_changed_payload(pending: dict | None, incoming: dict) ->
     pending_profile = _payload_profile(pending)
     incoming_profile = _payload_profile(incoming)
     if pending_profile == incoming_profile:
-        return incoming
+        pending_session_id = _payload_session_id(pending)
+        incoming_session_id = _payload_session_id(incoming)
+        if pending_session_id == incoming_session_id:
+            return incoming
+        merged = dict(incoming)
+        merged.pop("session_id", None)
+        return merged
     merged = dict(incoming)
     merged.pop("profile", None)
+    merged.pop("session_id", None)
     return merged
 
 
 def publish_session_list_changed(
     reason: str = "session_changed",
     profile: str | None = None,
+    session_id: str | None = None,
 ) -> None:
     """Notify connected browsers that the session sidebar may be stale."""
     global _SESSION_EVENTS_VERSION
@@ -82,6 +100,7 @@ def publish_session_list_changed(
             reason=reason,
             version=_SESSION_EVENTS_VERSION,
             profile=profile,
+            session_id=session_id,
         )
         subscribers = list(_SESSION_EVENTS_SUBSCRIBERS)
         listeners = list(_SESSION_LIST_CHANGED_LISTENERS)

static/sessions.js

@@ -3741,6 +3741,12 @@ function _scheduleSessionEventsRefresh(reason){
   }, 300);
 }
 
+function _sessionEventTargetsActiveSession(payload){
+  const eventSessionId = payload && typeof payload.session_id === 'string' ? payload.session_id : '';
+  if(!eventSessionId) return false;
+  return !!(S.session && S.session.session_id && S.session.session_id === eventSessionId);
+}
+
 // ── #4151: focus-aware close for the two GLOBAL sidebar SSE streams ──────────
 // Each WebUI window holds up to three persistent SSE connections (session-events
 // + gateway + the per-session stream). #3992/#3996 close them on the Page
@@ -3838,17 +3844,19 @@ function ensureSessionEventsSSE(){
     };
     _sessionEventsSSE.addEventListener('sessions_changed', (ev) => {
       const activeProfile = S.activeProfile || 'default';
+      let eventTargetsActiveSession = false;
       try {
         const payload = typeof ev?.data === 'string' ? JSON.parse(ev.data) : {};
         const eventProfile = payload && typeof payload.profile === 'string' ? payload.profile : '';
         if (!_sessionEventProfilesMatch(eventProfile, activeProfile)) {
           return;
         }
+        eventTargetsActiveSession = _sessionEventTargetsActiveSession(payload);
       } catch (_err) {
         // Non-JSON payload (or transient malformed event). Keep legacy behavior:
         // refresh once event was seen.
       }
-      _scheduleSessionEventsRefresh('event');
+      _scheduleSessionEventsRefresh(eventTargetsActiveSession?'event-active-session':'event');
     });
     _sessionEventsSSE.onerror = () => {
       _sessionEventsNeedsRefreshOnOpen = true;

tests/test_issue3225_rename_sync.py

@@ -21,11 +21,11 @@ def test_rename_endpoint_syncs_title_to_state_db():
         "rename handler must call _sync_session_title_to_insights(s) so the "
         "new title reaches state.db, matching the regenerate handler"
     )
-    assert 'publish_session_list_changed("session_rename", profile=getattr(s, "profile", None))' in block
+    assert 'publish_session_list_changed(\n            "session_rename",' in block
     # Sync must run BEFORE the list-changed publish, matching the regenerate
     # handler, so SSE subscribers refresh after state.db holds the new title.
     sync_idx = block.index("_sync_session_title_to_insights(s)")
-    publish_idx = block.index('publish_session_list_changed("session_rename", profile=getattr(s, "profile", None))')
+    publish_idx = block.index('publish_session_list_changed(\n            "session_rename",')
     assert sync_idx < publish_idx, (
         "rename must sync to state.db before publishing the list-changed event"
     )

tests/test_session_events.py

@@ -36,23 +36,23 @@ def test_session_events_publish_for_minimal_sidebar_mutations():
         elif reason == "session_import":
             assert f'publish_session_list_changed("{reason}")' in ROUTES, reason
         else:
-            assert f'publish_session_list_changed("{reason}",' in ROUTES, reason
+            assert f'"{reason}",' in ROUTES, reason
 
-    assert 'if worktree_info:\n            publish_session_list_changed("session_new", profile=getattr(s, "profile", None))' in ROUTES
+    assert 'if worktree_info:\n            publish_session_list_changed(\n                "session_new",' in ROUTES
     assert "was_hidden_empty_session = _is_hidden_empty_session(s)" in ROUTES
-    assert 'if was_hidden_empty_session:\n        publish_session_list_changed("session_new", profile=getattr(s, "profile", None))' in ROUTES
-    assert 'publish_session_list_changed("session_duplicate", profile=getattr(copied_session, "profile", None))' in ROUTES
-    assert 'publish_session_list_changed("session_rename", profile=getattr(s, "profile", None))' in ROUTES
+    assert 'if was_hidden_empty_session:\n        publish_session_list_changed(\n            "session_new",' in ROUTES
+    assert 'publish_session_list_changed(\n                "session_duplicate",' in ROUTES
+    assert 'publish_session_list_changed(\n            "session_rename",' in ROUTES
     assert '_persist_generated_session_title(s, next_title, event_reason="session_title_regenerate")' in ROUTES
-    assert '_publish_session_list_changed(event_reason, profile=getattr(session, "profile", None))' in ROUTES
+    assert "session_id=sid" in ROUTES
     assert 'event_profile = getattr(get_session(sid, metadata_only=True), "profile", None)' in ROUTES
     assert "Failed to resolve profile for deleted session" in ROUTES
     assert '_publish_session_list_changed("session_delete", profile=event_profile)' in ROUTES
-    assert 'publish_session_list_changed("session_branch", profile=getattr(branch, "profile", None))' in ROUTES
-    assert 'publish_session_list_changed("session_pin", profile=getattr(s, "profile", None))' in ROUTES
-    assert 'publish_session_list_changed("session_archive", profile=getattr(s, "profile", None))' in ROUTES
-    assert 'publish_session_list_changed("session_move", profile=getattr(s, "profile", None))' in ROUTES
-    assert 'profile=getattr(s, "profile", None)' in ROUTES
+    assert 'publish_session_list_changed(\n                "session_branch",' in ROUTES
+    assert 'publish_session_list_changed(\n            "session_pin",' in ROUTES
+    assert 'publish_session_list_changed(\n            "session_archive",' in ROUTES
+    assert 'publish_session_list_changed(\n            "session_move",' in ROUTES
+    assert 'session_id=getattr(' in ROUTES
     assert 'publish_session_list_changed("chat_start")' not in ROUTES
     assert '_publish_session_list_changed("cron_complete",' in ROUTES
     assert 'publish_session_list_changed("cron_complete",' in PROFILES
@@ -74,17 +74,70 @@ def test_session_event_queue_same_profile_is_bounded_and_latest_wins():
         session_events.unsubscribe_session_events(q)
 
 
+def test_session_events_payload_tracks_session_id_when_available():
+    from api import session_events
+
+    q = session_events.subscribe_session_events()
+    try:
+        session_events.publish_session_list_changed(
+            "session_rename",
+            profile="profile-a",
+            session_id="session-123",
+        )
+        payload = q.get_nowait()
+        assert payload["type"] == "sessions_changed"
+        assert payload["reason"] == "session_rename"
+        assert payload["profile"] == "profile-a"
+        assert payload["session_id"] == "session-123"
+    finally:
+        session_events.unsubscribe_session_events(q)
+
+
+def test_session_event_queue_same_profile_different_sessions_coalesces_to_profile_refresh():
+    from api import session_events
+
+    q = session_events.subscribe_session_events()
+    try:
+        session_events.publish_session_list_changed(
+            "session_rename",
+            profile="profile-a",
+            session_id="session-a",
+        )
+        session_events.publish_session_list_changed(
+            "session_pin",
+            profile="profile-a",
+            session_id="session-b",
+        )
+        payload = q.get_nowait()
+        assert payload["type"] == "sessions_changed"
+        assert payload["reason"] == "session_pin"
+        assert payload["profile"] == "profile-a"
+        assert "session_id" not in payload
+        assert q.empty()
+    finally:
+        session_events.unsubscribe_session_events(q)
+
+
 def test_session_event_queue_profile_mismatch_coalesces_to_unscoped_refresh_all():
     from api import session_events
 
     q = session_events.subscribe_session_events()
     try:
-        session_events.publish_session_list_changed("profile_a", profile="profile-a")
-        session_events.publish_session_list_changed("profile_b", profile="profile-b")
+        session_events.publish_session_list_changed(
+            "profile_a",
+            profile="profile-a",
+            session_id="session-a",
+        )
+        session_events.publish_session_list_changed(
+            "profile_b",
+            profile="profile-b",
+            session_id="session-b",
+        )
         payload = q.get_nowait()
         assert payload["type"] == "sessions_changed"
         assert payload["reason"] == "profile_b"
         assert "profile" not in payload
+        assert "session_id" not in payload
         assert q.empty()
     finally:
         session_events.unsubscribe_session_events(q)

tests/test_session_title_regenerate_controls.py

@@ -65,7 +65,8 @@ def test_regenerate_helper_persists_generated_title_and_publishes_sidebar_refres
     assert "mark_session_title_generated(session)" in helper_block
     assert "session.save(touch_updated_at=False)" in helper_block
     assert "_sync_session_title_to_insights(session)" in helper_block
-    assert '_publish_session_list_changed(event_reason, profile=getattr(session, "profile", None))' in helper_block
+    assert "_publish_session_list_changed(" in helper_block
+    assert "session_id=sid" in helper_block
 
 
 def test_regenerate_endpoint_syncs_title_to_state_db_when_enabled():

tests/test_webui_external_refresh_frontend.py

@@ -57,6 +57,9 @@ def test_session_list_external_refresh_uses_sse_invalidation_not_polling():
     assert "const payload = typeof ev?.data === 'string' ? JSON.parse(ev.data) : {};" in ensure_fn
     assert "const eventProfile = payload && typeof payload.profile === 'string' ? payload.profile : '';" in ensure_fn
     assert "if (!_sessionEventProfilesMatch(eventProfile, activeProfile)) {" in ensure_fn
+    assert "function _sessionEventTargetsActiveSession(payload)" in SESSIONS_JS
+    assert "typeof payload.session_id === 'string'" in SESSIONS_JS
+    assert "eventTargetsActiveSession?'event-active-session':'event'" in ensure_fn
 
 
 def test_session_event_profile_filter_tolerates_default_root_aliases():