fix(proxy): merge UI-added callbacks with config.yaml callbacks

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/proxy/proxy_server.py

@@ -3518,6 +3518,41 @@ _DB_OVERLAY_REMOTE_MODULE_LIST_FIELDS: Dict[str, Tuple[str, ...]] = {
     ),
 }
 
+_ADDITIVE_LITELLM_SETTINGS_LIST_FIELDS: tuple[str, ...] = (
+    "callbacks",
+    "success_callback",
+    "failure_callback",
+    "service_callback",
+    "audit_log_callbacks",
+)
+
+
+def _callback_dedup_key(callback: Any) -> Any:
+    return callback.lower() if isinstance(callback, str) else id(callback)
+
+
+def _union_callback_lists(config_value: Any, db_value: Any) -> Any:
+    """Union a config.yaml callback list with the DB-overlay one, config entries
+    first, deduped case-insensitively for plain string callback names."""
+    if not isinstance(config_value, list) or not isinstance(db_value, list):
+        return db_value
+    seen = frozenset(_callback_dedup_key(callback) for callback in config_value)
+    # mutable-ok: config consumers isinstance-check these callback entries for `list`
+    return [*config_value, *(cb for cb in db_value if _callback_dedup_key(cb) not in seen)]
+
+
+def _merge_additive_litellm_settings(current_config: dict[str, Any], db_param_value: dict[str, Any]) -> None:
+    """Fold the config.yaml callback lists into the DB-overlay ones, in place.
+
+    The DB row only holds the callbacks added from the Admin UI, so letting it
+    replace the config.yaml lists drops every YAML-declared logger."""
+    config_litellm_settings = current_config.get("litellm_settings")
+    if not isinstance(config_litellm_settings, dict):
+        return
+    for field in _ADDITIVE_LITELLM_SETTINGS_LIST_FIELDS:
+        if field in db_param_value:
+            db_param_value[field] = _union_callback_lists(config_litellm_settings.get(field), db_param_value[field])
+
 
 def _is_remote_module_url(value: Any) -> bool:
     return isinstance(value, str) and (value.startswith("s3://") or value.startswith("gcs://"))
@@ -6048,6 +6083,8 @@ class ProxyConfig:
                 if key in LITELLM_SETTINGS_SAFE_DB_OVERRIDES:  # params that are safe to override with db values
                     setattr(litellm, key, value)
 
+            _merge_additive_litellm_settings(current_config, db_param_value)
+
         # If param doesn't exist in config, add it
         if param_name not in current_config:
             current_config[param_name] = db_param_value

tests/test_litellm/proxy/test_proxy_server.py

@@ -5813,6 +5813,38 @@ def test_get_config_normalizes_string_callbacks(monkeypatch):
     assert "datadog" in success_and_failure_callbacks
 
 
+def test_update_config_fields_unions_callbacks_from_config_and_db():
+    """Issue #12118: callbacks added from the Admin UI land in the DB litellm_settings
+    row, which previously replaced the config.yaml callback lists on config load, so
+    only the UI-added loggers ran."""
+    from litellm.proxy.proxy_server import ProxyConfig
+
+    proxy_config = ProxyConfig()
+
+    updated = proxy_config._update_config_fields(
+        current_config={
+            "litellm_settings": {
+                "success_callback": ["langfuse"],
+                "failure_callback": ["sentry"],
+                "callbacks": ["otel"],
+                "drop_params": True,
+            }
+        },
+        param_name="litellm_settings",
+        db_param_value={
+            "success_callback": ["datadog", "Langfuse"],
+            "failure_callback": ["datadog"],
+            "callbacks": ["prometheus"],
+        },
+    )
+
+    ls = updated["litellm_settings"]
+    assert ls["success_callback"] == ["langfuse", "datadog"]
+    assert ls["failure_callback"] == ["sentry", "datadog"]
+    assert ls["callbacks"] == ["otel", "prometheus"]
+    assert ls["drop_params"] is True
+
+
 def test_deep_merge_dicts_skips_none_and_empty_lists(monkeypatch):
     """
     Test that _update_config_fields deep merge skips None values and empty lists.