diff --git a/frontend/src/agents/NewAgent.tsx b/frontend/src/agents/NewAgent.tsx
index 3f588a9e..72238d7e 100644
--- a/frontend/src/agents/NewAgent.tsx
+++ b/frontend/src/agents/NewAgent.tsx
@@ -235,32 +235,45 @@ export default function NewAgent({ mode }: { mode: 'new' | 'edit' | 'draft' }) {
   // source list; fall back to the owner-resolved name embedded in the agent
   // payload (source_details) so a team member viewing a shared agent sees the
   // source name instead of "External KB"; only then show the generic label.
-  const resolveSourceLabel = (id: string): string => {
-    const matchedDoc = sourceDocs?.find(
-      (source) => sourceItemId(source) === id,
-    );
-    if (matchedDoc?.name) return matchedDoc.name;
-    const detail = agent.source_details?.find((d) => d.id === id);
-    if (detail?.name) return detail.name;
-    return t('agents.form.externalKb');
-  };
-
-  const sourceItems = useMemo(
-    () =>
-      toSourcePickerItems(
-        sourceDocs,
-        {
-          own: t('agents.form.sourcePopup.groupOwn'),
-          team: t('agents.form.sourcePopup.groupTeam'),
-        },
-        SourceIcon,
-      ),
-    [sourceDocs, t],
+  const resolveSourceLabel = useCallback(
+    (id: string): string => {
+      const matchedDoc = sourceDocs?.find(
+        (source) => sourceItemId(source) === id,
+      );
+      if (matchedDoc?.name) return matchedDoc.name;
+      const detail = agent.source_details?.find((d) => d.id === id);
+      if (detail?.name) return detail.name;
+      return t('agents.form.externalKb');
+    },
+    [agent.source_details, sourceDocs, t],
   );
 
-  const selectedSourceNames = Array.from(selectedSourceIds)
-    .map((id) => resolveSourceLabel(id))
-    .filter(Boolean);
+  const sourceItems = useMemo(() => {
+    const items = toSourcePickerItems(
+      sourceDocs,
+      {
+        own: t('agents.form.sourcePopup.groupOwn'),
+        team: t('agents.form.sourcePopup.groupTeam'),
+      },
+      SourceIcon,
+    );
+    // An attached source the caller can't list — an owner's private source on
+    // a team-shared agent — still needs a row of its own, or it reads as
+    // selected with nothing to switch it off.
+    const listed = new Set(items.map((item) => item.id));
+    const unlisted = Array.from(selectedSourceIds)
+      .filter((id) => !listed.has(id))
+      .map((id) => ({ id, label: resolveSourceLabel(id), icon: SourceIcon }));
+    return [...items, ...unlisted];
+  }, [resolveSourceLabel, selectedSourceIds, sourceDocs, t]);
+
+  const selectedSourceNames = useMemo(
+    () =>
+      Array.from(selectedSourceIds)
+        .map((id) => resolveSourceLabel(id))
+        .filter(Boolean),
+    [resolveSourceLabel, selectedSourceIds],
+  );
   const sourceTriggerLabel =
     selectedSourceIds.size === 0
       ? t('agents.form.placeholders.selectSources')
@@ -667,7 +680,8 @@ export default function NewAgent({ mode }: { mode: 'new' | 'edit' | 'draft' }) {
         }
         const data = await response.json();
 
-        setSelectedSourceIds(new Set(selectedSourceIdsFromAgent(data)));
+        const agentSourceIds = selectedSourceIdsFromAgent(data);
+        setSelectedSourceIds(new Set(agentSourceIds));
 
         if (data.tool_details) setSelectedTools(data.tool_details);
         if (data.status === 'draft') setEffectiveMode('draft');
@@ -679,16 +693,22 @@ export default function NewAgent({ mode }: { mode: 'new' | 'edit' | 'draft' }) {
         // Backfill required fields so older agents (created before
         // agent_type / prompt_id / models existed) don't fail
         // ``isPublishable()`` and leave Save permanently disabled.
+        // Normalise exactly as the source and model effects below will, or the
+        // form compares unequal to this snapshot and reports unsaved changes
+        // before the user has touched anything.
+        const agentModels: string[] = data.models || [];
         const normalized = {
           ...data,
           agent_type: data.agent_type || 'classic',
           prompt_id: data.prompt_id || 'default',
-          retriever: data.retriever || 'classic',
+          retriever: agentSourceIds.length === 0 ? 'classic' : '',
           chunks: data.chunks || '2',
           tools: data.tools || [],
-          sources: data.sources || [],
-          models: data.models || [],
-          default_model_id: data.default_model_id || '',
+          ...serializeAgentSources(agentSourceIds, sourceDocs),
+          models: agentModels,
+          default_model_id: agentModels.includes(data.default_model_id || '')
+            ? data.default_model_id
+            : agentModels[0] || '',
           config: data.config || {},
         };
         setAgent(normalized);
@@ -1468,6 +1488,7 @@ export default function NewAgent({ mode }: { mode: 'new' | 'edit' | 'draft' }) {
           renderTab={null}
           close={() => setUploadModalState('INACTIVE')}
           onSuccessfulUpload={handleUploadedSource}
+          selectUploadedDoc={false}
         />
       )}
       <AddPromptModal
diff --git a/frontend/src/components/MessageInput.tsx b/frontend/src/components/MessageInput.tsx
index 3a3c9a58..ddff0c3f 100644
--- a/frontend/src/components/MessageInput.tsx
+++ b/frontend/src/components/MessageInput.tsx
@@ -3,6 +3,7 @@ import {
   useCallback,
   useEffect,
   useLayoutEffect,
+  useMemo,
   useRef,
   useState,
 } from 'react';
@@ -55,7 +56,7 @@ import {
   partitionAttachmentFiles,
 } from '../constants/fileUpload';
 import { UserToolType } from '../settings/types';
-import { sourceItemId } from '../utils/sourceUtils';
+import { sourceItemId, toSourcePickerItems } from '../utils/sourceUtils';
 import { isChatToolVisible } from '../utils/toolUtils';
 
 const generateId = (): string =>
@@ -1460,12 +1461,17 @@ export default function MessageInput({
     void _docs;
   };
 
-  const sourceItems: MultiSelectPopoverItem[] = (sourceDocs || []).map(
-    (doc) => ({
-      id: sourceItemId(doc),
-      label: doc.name,
-      icon: SourceIcon,
-    }),
+  const sourceItems: MultiSelectPopoverItem[] = useMemo(
+    () =>
+      toSourcePickerItems(
+        sourceDocs,
+        {
+          own: t('conversation.sources.groupOwn'),
+          team: t('conversation.sources.groupTeam'),
+        },
+        SourceIcon,
+      ),
+    [sourceDocs, t],
   );
 
   const selectedSourceIds = (
diff --git a/frontend/src/components/SourcesPopoverFooter.tsx b/frontend/src/components/SourcesPopoverFooter.tsx
index e918e718..056d47fc 100644
--- a/frontend/src/components/SourcesPopoverFooter.tsx
+++ b/frontend/src/components/SourcesPopoverFooter.tsx
@@ -1,4 +1,5 @@
 import { useTranslation } from 'react-i18next';
+import { Link } from 'react-router-dom';
 
 import RedirectIcon from '../assets/redirect.svg';
 import { Button } from './ui/button';
@@ -18,14 +19,14 @@ export default function SourcesPopoverFooter({
 
   return (
     <div className="flex flex-col gap-3">
-      <a
-        href="/settings/sources"
+      <Link
+        to="/settings/sources"
         className="text-primary inline-flex items-center gap-2 text-base font-medium"
         onClick={onNavigate}
       >
         {t('settings.sources.goToSources')}
         <img src={RedirectIcon} alt="" aria-hidden="true" className="h-3 w-3" />
-      </a>
+      </Link>
       <Button
         type="button"
         variant="outline"
diff --git a/frontend/src/locale/de.json b/frontend/src/locale/de.json
index 55c8763d..74848817 100644
--- a/frontend/src/locale/de.json
+++ b/frontend/src/locale/de.json
@@ -1089,7 +1089,9 @@
       "link": "Quellen-Link",
       "view_more": "{{count}} weitere Quellen",
       "noSourcesAvailable": "Keine Quellen verfügbar",
-      "selectedCount": "{{count}} Quellen ausgewählt"
+      "selectedCount": "{{count}} Quellen ausgewählt",
+      "groupOwn": "Deine Quellen",
+      "groupTeam": "Mit dem Team geteilt"
     },
     "attachments": {
       "attach": "Anhängen",
diff --git a/frontend/src/locale/en.json b/frontend/src/locale/en.json
index a1c86fdc..af03d4a2 100644
--- a/frontend/src/locale/en.json
+++ b/frontend/src/locale/en.json
@@ -1094,7 +1094,9 @@
       "link": "Source link",
       "view_more": "{{count}} more sources",
       "noSourcesAvailable": "No sources available",
-      "selectedCount": "{{count}} sources selected"
+      "selectedCount": "{{count}} sources selected",
+      "groupOwn": "Your sources",
+      "groupTeam": "Shared with team"
     },
     "attachments": {
       "attach": "Attach",
diff --git a/frontend/src/locale/es.json b/frontend/src/locale/es.json
index 4b5aadac..575e127c 100644
--- a/frontend/src/locale/es.json
+++ b/frontend/src/locale/es.json
@@ -1089,7 +1089,9 @@
       "link": "Enlace fuente",
       "view_more": "Ver {{count}} más fuentes",
       "noSourcesAvailable": "No hay fuentes disponibles",
-      "selectedCount": "{{count}} fuentes seleccionadas"
+      "selectedCount": "{{count}} fuentes seleccionadas",
+      "groupOwn": "Tus fuentes",
+      "groupTeam": "Compartidas con el equipo"
     },
     "attachments": {
       "attach": "Adjuntar",
diff --git a/frontend/src/locale/jp.json b/frontend/src/locale/jp.json
index bb407b25..70dd85d1 100644
--- a/frontend/src/locale/jp.json
+++ b/frontend/src/locale/jp.json
@@ -1089,7 +1089,9 @@
       "link": "ソースリンク",
       "view_more": "さらに{{count}}個のソース",
       "noSourcesAvailable": "利用可能なソースがありません",
-      "selectedCount": "{{count}} 件のソースを選択中"
+      "selectedCount": "{{count}} 件のソースを選択中",
+      "groupOwn": "自分のソース",
+      "groupTeam": "チームと共有"
     },
     "attachments": {
       "attach": "添付",
diff --git a/frontend/src/locale/ru.json b/frontend/src/locale/ru.json
index 1ee14216..92b6f533 100644
--- a/frontend/src/locale/ru.json
+++ b/frontend/src/locale/ru.json
@@ -1089,7 +1089,9 @@
       "link": "Ссылка на источник",
       "view_more": "ещё {{count}} источников",
       "noSourcesAvailable": "Нет доступных источников",
-      "selectedCount": "Выбрано источников: {{count}}"
+      "selectedCount": "Выбрано источников: {{count}}",
+      "groupOwn": "Ваши источники",
+      "groupTeam": "Общие с командой"
     },
     "attachments": {
       "attach": "Прикрепить",
diff --git a/frontend/src/locale/zh-TW.json b/frontend/src/locale/zh-TW.json
index 39981712..54de2c92 100644
--- a/frontend/src/locale/zh-TW.json
+++ b/frontend/src/locale/zh-TW.json
@@ -1089,7 +1089,9 @@
       "link": "來源連結",
       "view_more": "查看更多 {{count}} 個來源",
       "noSourcesAvailable": "沒有可用的來源",
-      "selectedCount": "已選擇 {{count}} 個來源"
+      "selectedCount": "已選擇 {{count}} 個來源",
+      "groupOwn": "我的來源",
+      "groupTeam": "團隊共享"
     },
     "attachments": {
       "attach": "附件",
diff --git a/frontend/src/locale/zh.json b/frontend/src/locale/zh.json
index ecfe0205..ccf4556f 100644
--- a/frontend/src/locale/zh.json
+++ b/frontend/src/locale/zh.json
@@ -1089,7 +1089,9 @@
       "link": "来源链接",
       "view_more": "还有{{count}}个来源",
       "noSourcesAvailable": "没有可用的来源",
-      "selectedCount": "已选择 {{count}} 个来源"
+      "selectedCount": "已选择 {{count}} 个来源",
+      "groupOwn": "我的来源",
+      "groupTeam": "团队共享"
     },
     "attachments": {
       "attach": "附件",
diff --git a/frontend/src/preferences/preferenceSlice.test.ts b/frontend/src/preferences/preferenceSlice.test.ts
index cf9480e5..9ac8cb3a 100644
--- a/frontend/src/preferences/preferenceSlice.test.ts
+++ b/frontend/src/preferences/preferenceSlice.test.ts
@@ -1,12 +1,16 @@
-import { describe, expect, it } from 'vitest';
+import { configureStore } from '@reduxjs/toolkit';
+import { beforeEach, describe, expect, it } from 'vitest';
 
+import type { Doc } from '../models/misc';
 import type { RootState } from '../store';
 import reducer, {
   clearRoles,
+  prefListenerMiddleware,
   selectIsAdmin,
   selectRoles,
   selectRolesResolved,
   setRoles,
+  setSourceDocs,
 } from './preferenceSlice';
 
 const baseState = () => reducer(undefined, { type: '@@INIT' });
@@ -47,3 +51,54 @@ describe('roles selectors', () => {
     expect(selectRolesResolved(stateWith(['user'], false))).toBe(false);
   });
 });
+
+const sourceDoc = (overrides: Partial<Doc>): Doc => ({
+  name: 'doc',
+  date: '2026-01-01',
+  model: 'm',
+  ...overrides,
+});
+
+const storeWithListener = () =>
+  configureStore({
+    reducer: { preference: reducer },
+    middleware: (getDefault) =>
+      getDefault().prepend(prefListenerMiddleware.middleware),
+  });
+
+describe('setSourceDocs reconciler', () => {
+  beforeEach(() => {
+    localStorage.clear();
+  });
+
+  it('prunes a stored selection when the source list comes back empty', () => {
+    const stored = [sourceDoc({ id: 'gone', name: 'Deleted' })];
+    localStorage.setItem('DocsGPTRecentDocs', JSON.stringify(stored));
+    const store = storeWithListener();
+
+    store.dispatch(setSourceDocs([]));
+
+    expect(store.getState().preference.selectedDocs).toEqual([]);
+    expect(localStorage.getItem('DocsGPTRecentDocs')).toBeNull();
+  });
+
+  it('keeps a stored selection that is still in the list', () => {
+    const kept = sourceDoc({ id: 'kept', name: 'Kept' });
+    localStorage.setItem('DocsGPTRecentDocs', JSON.stringify([kept]));
+    const store = storeWithListener();
+
+    store.dispatch(setSourceDocs([kept, sourceDoc({ id: 'other' })]));
+
+    expect(store.getState().preference.selectedDocs).toEqual([kept]);
+  });
+
+  it('leaves the selection alone while the list has not loaded', () => {
+    const stored = [sourceDoc({ id: 'pending' })];
+    localStorage.setItem('DocsGPTRecentDocs', JSON.stringify(stored));
+    const store = storeWithListener();
+
+    store.dispatch(setSourceDocs(null));
+
+    expect(localStorage.getItem('DocsGPTRecentDocs')).not.toBeNull();
+  });
+});
diff --git a/frontend/src/preferences/preferenceSlice.ts b/frontend/src/preferences/preferenceSlice.ts
index 6f8bfc31..e12a144b 100644
--- a/frontend/src/preferences/preferenceSlice.ts
+++ b/frontend/src/preferences/preferenceSlice.ts
@@ -214,14 +214,12 @@ prefListenerMiddleware.startListening({
   effect: (_action, listenerApi) => {
     const state = listenerApi.getState() as RootState;
     const sourceDocs = state.preference.sourceDocs;
-    if (sourceDocs && sourceDocs.length > 0) {
-      const validatedDocs = getLocalRecentDocs(sourceDocs);
-      if (validatedDocs !== null) {
-        listenerApi.dispatch(setSelectedDocs(validatedDocs));
-      } else {
-        listenerApi.dispatch(setSelectedDocs([]));
-      }
-    }
+    // ``null`` means the list hasn't loaded; an empty array is a real answer
+    // and still has to prune a stored selection, or a deleted last source
+    // stays checked forever.
+    if (!sourceDocs) return;
+    const validatedDocs = getLocalRecentDocs(sourceDocs);
+    listenerApi.dispatch(setSelectedDocs(validatedDocs ?? []));
   },
 });
 
diff --git a/frontend/src/upload/Upload.tsx b/frontend/src/upload/Upload.tsx
index 2ea56566..fe6a22cd 100644
--- a/frontend/src/upload/Upload.tsx
+++ b/frontend/src/upload/Upload.tsx
@@ -61,6 +61,7 @@ function Upload({
   renderTab = null,
   close,
   onSuccessfulUpload = () => undefined,
+  selectUploadedDoc = true,
 }: {
   receivedFile: File[];
   setModalState: (state: ActiveState) => void;
@@ -69,6 +70,12 @@ function Upload({
   close: () => void;
   /** Fires once the upload is ingested, with the id of the source it created. */
   onSuccessfulUpload?: (sourceId?: string) => void;
+  /**
+   * Whether a finished upload also becomes the chat's selected source. Callers
+   * that only need the new source's id (the agent builder) pass ``false`` so
+   * uploading never repoints the conversation the user left open.
+   */
+  selectUploadedDoc?: boolean;
 }) {
   const token = useSelector(selectToken);
   const selectedDocs = useSelector(selectSelectedDocs);
@@ -431,6 +438,32 @@ function Upload({
     [dispatch],
   );
 
+  /** Re-read the source list into the store so a new source is pickable. */
+  const refreshSourceDocs = useCallback(
+    () =>
+      getDocs(token).then((docs) => {
+        dispatch(setSourceDocs(docs));
+        return docs;
+      }),
+    [dispatch, token],
+  );
+
+  /**
+   * Finish an upload that never got an ingest task (the wiki source is created
+   * synchronously). The list still has to be refreshed, or the caller selects
+   * an id no picker can render.
+   */
+  const finishUntrackedUpload = useCallback(
+    (sourceId?: string) => {
+      refreshSourceDocs()
+        .catch((err) => {
+          console.error('Post-upload source-list refresh failed:', err);
+        })
+        .finally(() => onSuccessfulUpload?.(sourceId));
+    },
+    [onSuccessfulUpload, refreshSourceDocs],
+  );
+
   /**
    * Wait for the source.ingest.* SSE pipeline to flip this task into a
    * terminal state, then run the post-completion side effects: refresh
@@ -450,10 +483,9 @@ function Upload({
         if (handled) return;
         handled = true;
         if (status !== 'completed') return;
-        getDocs(token)
+        refreshSourceDocs()
           .then((docs) => {
-            dispatch(setSourceDocs(docs));
-            if (Array.isArray(docs)) {
+            if (selectUploadedDoc && Array.isArray(docs)) {
               const existingDocIds = new Set(
                 (Array.isArray(sourceDocs) ? sourceDocs : [])
                   .map((doc: Doc) => doc?.id)
@@ -540,7 +572,15 @@ function Upload({
         }
       });
     },
-    [dispatch, onSuccessfulUpload, selectedDocs, sourceDocs, store, token],
+    [
+      dispatch,
+      onSuccessfulUpload,
+      refreshSourceDocs,
+      selectedDocs,
+      selectUploadedDoc,
+      sourceDocs,
+      store,
+    ],
   );
 
   const onDrop = useCallback(
@@ -630,7 +670,7 @@ function Upload({
                 updates: { status: 'completed', progress: 100 },
               }),
             );
-            onSuccessfulUpload?.(parsed.source_id);
+            finishUntrackedUpload(parsed.source_id);
           }
         } catch (error) {
           handleTaskFailure(clientTaskId);
@@ -766,7 +806,7 @@ function Upload({
                 updates: { status: 'completed', progress: 100 },
               }),
             );
-            onSuccessfulUpload?.(response.source_id);
+            finishUntrackedUpload(response.source_id);
           }
         } catch (error) {
           handleTaskFailure(clientTaskId);
@@ -817,7 +857,7 @@ function Upload({
             },
           }),
         );
-        onSuccessfulUpload?.(data.source_id);
+        finishUntrackedUpload(data.source_id);
       })
       .catch(() => handleTaskFailure(clientTaskId));
   };
diff --git a/frontend/src/utils/sourceUtils.test.ts b/frontend/src/utils/sourceUtils.test.ts
index 913c43f7..16ffe547 100644
--- a/frontend/src/utils/sourceUtils.test.ts
+++ b/frontend/src/utils/sourceUtils.test.ts
@@ -115,9 +115,15 @@ describe('serializeAgentSources', () => {
 });
 
 describe('selectedSourceIdsFromAgent', () => {
-  it('prefers the sources list over the single source', () => {
+  it('merges the single source with the sources list', () => {
     expect(
       selectedSourceIdsFromAgent({ source: 'x', sources: ['a', 'b'] }),
+    ).toEqual(['x', 'a', 'b']);
+  });
+
+  it('keeps a source named in both fields once', () => {
+    expect(
+      selectedSourceIdsFromAgent({ source: 'a', sources: ['a', 'b'] }),
     ).toEqual(['a', 'b']);
   });
 
diff --git a/frontend/src/utils/sourceUtils.ts b/frontend/src/utils/sourceUtils.ts
index 3683ee79..8a8ae39b 100644
--- a/frontend/src/utils/sourceUtils.ts
+++ b/frontend/src/utils/sourceUtils.ts
@@ -56,18 +56,20 @@ export function serializeAgentSources(
 }
 
 /**
- * Selected source ids for a stored agent. ``sources`` wins over the legacy
- * single ``source``; the legacy ``"default"`` placeholder means no source.
+ * Selected source ids for a stored agent: the legacy single ``source`` and the
+ * ``sources`` list merged, because retrieval reads both. Preferring one over
+ * the other would drop the omitted field on the next save. The legacy
+ * ``"default"`` placeholder means no source.
  */
 export function selectedSourceIdsFromAgent(agent: {
   source?: string;
   sources?: string[];
 }): string[] {
-  const ids =
-    agent.sources && agent.sources.length > 0
-      ? agent.sources
-      : agent.source
-        ? [agent.source]
-        : [];
-  return ids.filter((id) => Boolean(id) && id !== 'default');
+  const ids = [
+    ...(agent.source ? [agent.source] : []),
+    ...(agent.sources ?? []),
+  ];
+  return Array.from(new Set(ids)).filter(
+    (id) => Boolean(id) && id !== 'default',
+  );
 }