diff --git a/application/agents/tools/wiki.py b/application/agents/tools/wiki.py
index f8c009a9..7378cf8b 100644
--- a/application/agents/tools/wiki.py
+++ b/application/agents/tools/wiki.py
@@ -15,6 +15,8 @@ logger = logging.getLogger(__name__)
 
 WIKI_TOOL_ID = "wiki"
 
+WIKI_UPDATED_VIA_AGENT = "agent"
+
 MAX_WIKI_PAGE_BYTES = 1_000_000
 
 
@@ -313,6 +315,7 @@ class WikiTool(Tool):
                     validated_path,
                     content,
                     updated_by=self.updated_by,
+                    updated_via=WIKI_UPDATED_VIA_AGENT,
                     expected_version=(
                         existing.get("version") if existing else None
                     ),
@@ -357,6 +360,7 @@ class WikiTool(Tool):
                     updated,
                     title=page.get("title"),
                     updated_by=self.updated_by,
+                    updated_via=WIKI_UPDATED_VIA_AGENT,
                     expected_version=page.get("version"),
                 )
             except WikiPageConflict:
@@ -395,6 +399,7 @@ class WikiTool(Tool):
                     updated,
                     title=page.get("title"),
                     updated_by=self.updated_by,
+                    updated_via=WIKI_UPDATED_VIA_AGENT,
                     expected_version=page.get("version"),
                 )
             except WikiPageConflict:
diff --git a/application/alembic/versions/0024_wiki_pages_updated_via.py b/application/alembic/versions/0024_wiki_pages_updated_via.py
new file mode 100644
index 00000000..7ad14604
--- /dev/null
+++ b/application/alembic/versions/0024_wiki_pages_updated_via.py
@@ -0,0 +1,28 @@
+"""0024 wiki pages updated_via — provenance of the last page write.
+
+Adds a nullable ``updated_via`` column recording which channel last wrote a
+page ("agent" via the WikiTool/conversion, "human" via the edit endpoint) so the
+viewer can stamp each page's provenance alongside ``updated_by`` / ``updated_at``
+/ ``version``.
+
+Revision ID: 0024_wiki_pages_updated_via
+Revises: 0023_wiki_pages
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+
+
+revision: str = "0024_wiki_pages_updated_via"
+down_revision: Union[str, None] = "0023_wiki_pages"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.execute("ALTER TABLE wiki_pages ADD COLUMN IF NOT EXISTS updated_via TEXT;")
+
+
+def downgrade() -> None:
+    op.execute("ALTER TABLE wiki_pages DROP COLUMN IF EXISTS updated_via;")
diff --git a/application/api/user/sources/routes.py b/application/api/user/sources/routes.py
index a8449bc2..d5d98b0d 100644
--- a/application/api/user/sources/routes.py
+++ b/application/api/user/sources/routes.py
@@ -697,6 +697,7 @@ def _wiki_page_node(page):
         "version": page.get("version"),
         "embed_status": page.get("embed_status"),
         "updated_by": page.get("updated_by"),
+        "updated_via": page.get("updated_via"),
         "updated_at": (
             page["updated_at"].isoformat()
             if page.get("updated_at") is not None
@@ -769,6 +770,7 @@ class CreateWikiSource(Resource):
                         WIKI_INDEX_PATH,
                         initial_content,
                         updated_by=user,
+                        updated_via="human",
                     )
                     rebuild_wiki_directory_structure(conn, source_id, user)
         except Exception as err:
@@ -922,6 +924,7 @@ class WikiPage(Resource):
                         path,
                         content,
                         updated_by=user,
+                        updated_via="human",
                         expected_version=expected_version,
                     )
                 except WikiPageConflict:
diff --git a/application/storage/db/models.py b/application/storage/db/models.py
index 2f2d3f56..50df6bcb 100644
--- a/application/storage/db/models.py
+++ b/application/storage/db/models.py
@@ -431,6 +431,7 @@ wiki_pages_table = Table(
     Column("content_hash", Text),
     Column("embed_status", Text, nullable=False, server_default="pending"),
     Column("updated_by", Text),
+    Column("updated_via", Text),
     Column("created_at", DateTime(timezone=True), nullable=False, server_default=func.now()),
     Column("updated_at", DateTime(timezone=True), nullable=False, server_default=func.now()),
     UniqueConstraint("source_id", "path", name="wiki_pages_source_path_uidx"),
diff --git a/application/storage/db/repositories/wiki_pages.py b/application/storage/db/repositories/wiki_pages.py
index 47db1996..fcb07233 100644
--- a/application/storage/db/repositories/wiki_pages.py
+++ b/application/storage/db/repositories/wiki_pages.py
@@ -37,6 +37,7 @@ class WikiPagesRepository:
         content: str,
         title: Optional[str] = None,
         updated_by: Optional[str] = None,
+        updated_via: Optional[str] = None,
         expected_version: Optional[int] = None,
     ) -> dict:
         """Create or overwrite a page.
@@ -67,6 +68,7 @@ class WikiPagesRepository:
                         token_count = :token_count,
                         content_hash = :content_hash,
                         updated_by = :updated_by,
+                        updated_via = :updated_via,
                         version = version + 1,
                         embed_status = 'pending',
                         updated_at = now()
@@ -84,6 +86,7 @@ class WikiPagesRepository:
                     "token_count": num_tokens_from_string(content),
                     "content_hash": content_hash,
                     "updated_by": updated_by,
+                    "updated_via": updated_via,
                     "expected_version": expected_version,
                 },
             )
@@ -100,10 +103,10 @@ class WikiPagesRepository:
                 """
                 INSERT INTO wiki_pages
                     (source_id, path, title, content, token_count,
-                     content_hash, updated_by, embed_status)
+                     content_hash, updated_by, updated_via, embed_status)
                 VALUES
                     (CAST(:source_id AS uuid), :path, :title, :content, :token_count,
-                     :content_hash, :updated_by, 'pending')
+                     :content_hash, :updated_by, :updated_via, 'pending')
                 ON CONFLICT (source_id, path)
                 DO UPDATE SET
                     title = EXCLUDED.title,
@@ -111,6 +114,7 @@ class WikiPagesRepository:
                     token_count = EXCLUDED.token_count,
                     content_hash = EXCLUDED.content_hash,
                     updated_by = EXCLUDED.updated_by,
+                    updated_via = EXCLUDED.updated_via,
                     version = wiki_pages.version + 1,
                     embed_status = 'pending',
                     updated_at = now()
@@ -125,6 +129,7 @@ class WikiPagesRepository:
                 "token_count": num_tokens_from_string(content),
                 "content_hash": content_hash,
                 "updated_by": updated_by,
+                "updated_via": updated_via,
             },
         )
         return row_to_dict(result.fetchone())
diff --git a/application/worker.py b/application/worker.py
index 0a8bc98e..17962460 100755
--- a/application/worker.py
+++ b/application/worker.py
@@ -2158,7 +2158,12 @@ def convert_source_to_wiki_worker(self, source_id, user):
                     rel_path
                 )
                 repo.upsert(
-                    source_id, page_path, content, title=title, updated_by=user
+                    source_id,
+                    page_path,
+                    content,
+                    title=title,
+                    updated_by=user,
+                    updated_via="agent",
                 )
                 created_pages.append((page_path, _content_hash(content)))
 
diff --git a/frontend/src/api/services/userService.ts b/frontend/src/api/services/userService.ts
index c78fb433..98ef4d74 100644
--- a/frontend/src/api/services/userService.ts
+++ b/frontend/src/api/services/userService.ts
@@ -115,6 +115,12 @@ const userService = {
     token: string | null,
   ): Promise<Response> =>
     throttledApiClient.get(endpoints.USER.WIKI_PAGE(sourceId, path), token),
+  updateWikiPage: (
+    sourceId: string,
+    data: { path: string; content: string; expected_version?: number },
+    token: string | null,
+  ): Promise<Response> =>
+    apiClient.put(endpoints.USER.WIKI_PAGE(sourceId, data.path), data, token),
   getAvailableTools: (token: string | null): Promise<any> =>
     apiClient.get(endpoints.USER.GET_AVAILABLE_TOOLS, token),
   getUserTools: (token: string | null): Promise<any> =>
diff --git a/frontend/src/components/WikiViewer.tsx b/frontend/src/components/WikiViewer.tsx
index 8633d847..64f1e63e 100644
--- a/frontend/src/components/WikiViewer.tsx
+++ b/frontend/src/components/WikiViewer.tsx
@@ -7,36 +7,83 @@ import remarkGfm from 'remark-gfm';
 import userService from '../api/services/userService';
 import ArrowLeft from '../assets/arrow-left.svg';
 import { selectToken } from '../preferences/preferenceSlice';
+import { decodeJwtPayload } from '../utils/jwtUtils';
 import { Button } from './ui/button';
 import SkeletonLoader from './SkeletonLoader';
-
-interface WikiPageNode {
-  path: string;
-  title?: string | null;
-  token_count?: number;
-  embed_status?: string;
-}
+import {
+  WikiPageNode,
+  formatRelativeTime,
+  provenanceKey,
+  saveWikiPage,
+} from './wikiViewerUtils';
 
 interface WikiViewerProps {
   docId: string;
   sourceName: string;
+  canEdit?: boolean;
   onBackToDocuments: () => void;
 }
 
+const markdownComponents = {
+  h1: ({ children }: { children?: React.ReactNode }) => (
+    <h1 className="mt-4 mb-2 text-xl font-semibold">{children}</h1>
+  ),
+  h2: ({ children }: { children?: React.ReactNode }) => (
+    <h2 className="mt-4 mb-2 text-lg font-semibold">{children}</h2>
+  ),
+  h3: ({ children }: { children?: React.ReactNode }) => (
+    <h3 className="mt-3 mb-2 text-base font-semibold">{children}</h3>
+  ),
+  p: ({ children }: { children?: React.ReactNode }) => (
+    <p className="mb-3">{children}</p>
+  ),
+  ul: ({ children }: { children?: React.ReactNode }) => (
+    <ul className="mb-3 list-inside list-disc pl-4">{children}</ul>
+  ),
+  ol: ({ children }: { children?: React.ReactNode }) => (
+    <ol className="mb-3 list-inside list-decimal pl-4">{children}</ol>
+  ),
+  a: ({ children, href }: { children?: React.ReactNode; href?: string }) => (
+    <a
+      href={href}
+      target="_blank"
+      rel="noreferrer"
+      className="text-primary underline"
+    >
+      {children}
+    </a>
+  ),
+  code: ({ children }: { children?: React.ReactNode }) => (
+    <code className="dark:bg-accent rounded-md bg-gray-200 px-1.5 py-0.5 text-xs">
+      {children}
+    </code>
+  ),
+};
+
 const WikiViewer: React.FC<WikiViewerProps> = ({
   docId,
   sourceName,
+  canEdit = false,
   onBackToDocuments,
 }) => {
   const { t } = useTranslation();
   const token = useSelector(selectToken);
+  const currentUserSub = token
+    ? ((decodeJwtPayload(token)?.sub as string | undefined) ?? null)
+    : null;
 
   const [pages, setPages] = useState<WikiPageNode[]>([]);
   const [selectedPath, setSelectedPath] = useState<string | null>(null);
+  const [page, setPage] = useState<WikiPageNode | null>(null);
   const [content, setContent] = useState<string>('');
   const [loadingPages, setLoadingPages] = useState(true);
   const [loadingContent, setLoadingContent] = useState(false);
 
+  const [isEditing, setIsEditing] = useState(false);
+  const [draft, setDraft] = useState<string>('');
+  const [saving, setSaving] = useState(false);
+  const [editError, setEditError] = useState<string | null>(null);
+
   useEffect(() => {
     let cancelled = false;
     setLoadingPages(true);
@@ -59,7 +106,10 @@ const WikiViewer: React.FC<WikiViewerProps> = ({
   }, [docId, token]);
 
   useEffect(() => {
+    setIsEditing(false);
+    setEditError(null);
     if (!selectedPath) {
+      setPage(null);
       setContent('');
       return;
     }
@@ -70,7 +120,9 @@ const WikiViewer: React.FC<WikiViewerProps> = ({
       .then((response) => response.json())
       .then((data) => {
         if (cancelled) return;
-        setContent(data?.page?.content ?? '');
+        const node: WikiPageNode | null = data?.page ?? null;
+        setPage(node);
+        setContent((data?.page?.content as string) ?? '');
       })
       .catch((error) => console.error('Error loading wiki page:', error))
       .finally(() => {
@@ -81,6 +133,76 @@ const WikiViewer: React.FC<WikiViewerProps> = ({
     };
   }, [docId, selectedPath, token]);
 
+  const startEditing = () => {
+    setDraft(content);
+    setEditError(null);
+    setIsEditing(true);
+  };
+
+  const cancelEditing = () => {
+    setIsEditing(false);
+    setEditError(null);
+  };
+
+  const handleSave = async () => {
+    if (!selectedPath) return;
+    setSaving(true);
+    setEditError(null);
+    try {
+      const outcome = await saveWikiPage(
+        userService,
+        docId,
+        selectedPath,
+        draft,
+        page?.version,
+        token,
+      );
+      switch (outcome.status) {
+        case 'saved':
+          if (outcome.page) setPage(outcome.page);
+          setContent(draft);
+          setIsEditing(false);
+          break;
+        case 'conflict':
+          if (outcome.page) {
+            setPage(outcome.page);
+            setContent(outcome.page.content ?? '');
+          }
+          setEditError(t('settings.sources.wiki.conflict'));
+          break;
+        case 'forbidden':
+          setEditError(t('settings.sources.wiki.forbidden'));
+          break;
+        default:
+          setEditError(t('settings.sources.wiki.saveFailed'));
+      }
+    } catch (error) {
+      console.error('Error saving wiki page:', error);
+      setEditError(t('settings.sources.wiki.saveFailed'));
+    } finally {
+      setSaving(false);
+    }
+  };
+
+  const provenanceLabel = (via?: string | null, by?: string | null): string =>
+    t(`settings.sources.wiki.stamp.${provenanceKey(via, by, currentUserSub)}`);
+
+  const renderStamp = () => {
+    if (!page) return null;
+    const who = provenanceLabel(page.updated_via, page.updated_by);
+    const when = formatRelativeTime(page.updated_at);
+    const parts = [t('settings.sources.wiki.stamp.editedBy', { who })];
+    if (when) parts.push(when);
+    if (page.version != null) {
+      parts.push(
+        t('settings.sources.wiki.stamp.version', { version: page.version }),
+      );
+    }
+    return (
+      <p className="text-muted-foreground mb-3 text-xs">{parts.join(' · ')}</p>
+    );
+  };
+
   return (
     <div className="flex flex-col">
       <div className="mb-4 flex items-center">
@@ -109,19 +231,19 @@ const WikiViewer: React.FC<WikiViewerProps> = ({
             </p>
           ) : (
             <ul className="flex flex-col gap-1">
-              {pages.map((page) => (
-                <li key={page.path}>
+              {pages.map((p) => (
+                <li key={p.path}>
                   <button
                     type="button"
-                    onClick={() => setSelectedPath(page.path)}
+                    onClick={() => setSelectedPath(p.path)}
                     className={`w-full truncate rounded-lg px-3 py-2 text-left text-sm transition-colors ${
-                      selectedPath === page.path
+                      selectedPath === p.path
                         ? 'bg-muted text-foreground dark:bg-accent'
                         : 'text-muted-foreground hover:bg-muted dark:hover:bg-accent'
                     }`}
-                    title={page.path}
+                    title={p.path}
                   >
-                    {page.title || page.path}
+                    {p.title || p.path}
                   </button>
                 </li>
               ))}
@@ -133,56 +255,72 @@ const WikiViewer: React.FC<WikiViewerProps> = ({
           {loadingContent ? (
             <SkeletonLoader count={4} />
           ) : selectedPath ? (
-            <article className="text-foreground max-w-none text-sm leading-relaxed wrap-break-word">
-              <ReactMarkdown
-                remarkPlugins={[remarkGfm]}
-                components={{
-                  h1: ({ children }) => (
-                    <h1 className="mt-4 mb-2 text-xl font-semibold">
-                      {children}
-                    </h1>
-                  ),
-                  h2: ({ children }) => (
-                    <h2 className="mt-4 mb-2 text-lg font-semibold">
-                      {children}
-                    </h2>
-                  ),
-                  h3: ({ children }) => (
-                    <h3 className="mt-3 mb-2 text-base font-semibold">
-                      {children}
-                    </h3>
-                  ),
-                  p: ({ children }) => <p className="mb-3">{children}</p>,
-                  ul: ({ children }) => (
-                    <ul className="mb-3 list-inside list-disc pl-4">
-                      {children}
-                    </ul>
-                  ),
-                  ol: ({ children }) => (
-                    <ol className="mb-3 list-inside list-decimal pl-4">
-                      {children}
-                    </ol>
-                  ),
-                  a: ({ children, href }) => (
-                    <a
-                      href={href}
-                      target="_blank"
-                      rel="noreferrer"
-                      className="text-primary underline"
+            <div className="flex flex-col">
+              <div className="mb-2 flex items-center justify-between gap-2">
+                {renderStamp()}
+                {canEdit && !isEditing && (
+                  <Button
+                    type="button"
+                    variant="outline"
+                    size="sm"
+                    onClick={startEditing}
+                  >
+                    {t('settings.sources.wiki.edit')}
+                  </Button>
+                )}
+              </div>
+
+              {editError && (
+                <p
+                  role="alert"
+                  className="border-border text-muted-foreground mb-3 rounded-md border px-3 py-2 text-xs"
+                >
+                  {editError}
+                </p>
+              )}
+
+              {isEditing ? (
+                <div className="flex flex-col gap-3">
+                  <textarea
+                    value={draft}
+                    onChange={(e) => setDraft(e.target.value)}
+                    placeholder={t('settings.sources.wiki.editPlaceholder')}
+                    className="border-border bg-card text-foreground min-h-[320px] w-full resize-y rounded-md border p-3 font-mono text-sm leading-relaxed"
+                    aria-label={selectedPath}
+                  />
+                  <div className="flex items-center gap-2">
+                    <Button
+                      type="button"
+                      size="sm"
+                      onClick={handleSave}
+                      disabled={saving}
                     >
-                      {children}
-                    </a>
-                  ),
-                  code: ({ children }) => (
-                    <code className="dark:bg-accent rounded-md bg-gray-200 px-1.5 py-0.5 text-xs">
-                      {children}
-                    </code>
-                  ),
-                }}
-              >
-                {content}
-              </ReactMarkdown>
-            </article>
+                      {saving
+                        ? t('settings.sources.wiki.saving')
+                        : t('settings.sources.wiki.save')}
+                    </Button>
+                    <Button
+                      type="button"
+                      variant="outline"
+                      size="sm"
+                      onClick={cancelEditing}
+                      disabled={saving}
+                    >
+                      {t('settings.sources.wiki.cancel')}
+                    </Button>
+                  </div>
+                </div>
+              ) : (
+                <article className="text-foreground max-w-none text-sm leading-relaxed wrap-break-word">
+                  <ReactMarkdown
+                    remarkPlugins={[remarkGfm]}
+                    components={markdownComponents}
+                  >
+                    {content}
+                  </ReactMarkdown>
+                </article>
+              )}
+            </div>
           ) : (
             <p className="text-muted-foreground py-2 text-sm">
               {t('settings.sources.wiki.selectPage')}
diff --git a/frontend/src/components/wikiViewerUtils.test.ts b/frontend/src/components/wikiViewerUtils.test.ts
new file mode 100644
index 00000000..73461e80
--- /dev/null
+++ b/frontend/src/components/wikiViewerUtils.test.ts
@@ -0,0 +1,142 @@
+import { describe, expect, it, vi } from 'vitest';
+
+import {
+  formatRelativeTime,
+  provenanceKey,
+  saveWikiPage,
+} from './wikiViewerUtils';
+
+const jsonResponse = (status: number, body: unknown): Response =>
+  ({
+    ok: status >= 200 && status < 300,
+    status,
+    json: () => Promise.resolve(body),
+  }) as unknown as Response;
+
+describe('formatRelativeTime', () => {
+  const now = Date.parse('2026-06-22T12:00:00Z');
+
+  it('returns null for empty or invalid values', () => {
+    expect(formatRelativeTime(null, now)).toBeNull();
+    expect(formatRelativeTime(undefined, now)).toBeNull();
+    expect(formatRelativeTime('not-a-date', now)).toBeNull();
+  });
+
+  it('formats a recent edit in minutes', () => {
+    const fiveMinAgo = new Date(now - 5 * 60000).toISOString();
+    expect(formatRelativeTime(fiveMinAgo, now)).toBe('5 minutes ago');
+  });
+
+  it('formats an older edit in days', () => {
+    const threeDaysAgo = new Date(now - 3 * 86400000).toISOString();
+    expect(formatRelativeTime(threeDaysAgo, now)).toBe('3 days ago');
+  });
+});
+
+describe('provenanceKey', () => {
+  it('maps the current user to "you"', () => {
+    expect(provenanceKey('human', 'user-1', 'user-1')).toBe('you');
+  });
+
+  it('maps agent and human writes', () => {
+    expect(provenanceKey('agent', 'someone', 'user-1')).toBe('agent');
+    expect(provenanceKey('human', 'someone', 'user-1')).toBe('human');
+  });
+
+  it('falls back to "unknown" for missing provenance', () => {
+    expect(provenanceKey(null, null, null)).toBe('unknown');
+    expect(provenanceKey('weird', 'someone', 'user-1')).toBe('unknown');
+  });
+});
+
+describe('saveWikiPage', () => {
+  it('sends expected_version and returns the saved page', async () => {
+    const updateWikiPage = vi
+      .fn()
+      .mockResolvedValue(
+        jsonResponse(200, { page: { path: '/a.md', version: 3 } }),
+      );
+    const getWikiPage = vi.fn();
+    const service = { updateWikiPage, getWikiPage };
+
+    const outcome = await saveWikiPage(
+      service,
+      'src-1',
+      '/a.md',
+      'new body',
+      2,
+      'tok',
+    );
+
+    expect(updateWikiPage).toHaveBeenCalledWith(
+      'src-1',
+      { path: '/a.md', content: 'new body', expected_version: 2 },
+      'tok',
+    );
+    expect(getWikiPage).not.toHaveBeenCalled();
+    expect(outcome).toEqual({
+      status: 'saved',
+      page: { path: '/a.md', version: 3 },
+    });
+  });
+
+  it('reloads the latest page on a 409 conflict', async () => {
+    const updateWikiPage = vi.fn().mockResolvedValue(jsonResponse(409, {}));
+    const getWikiPage = vi.fn().mockResolvedValue(
+      jsonResponse(200, {
+        page: { path: '/a.md', version: 5, content: 'their edit' },
+      }),
+    );
+    const service = { updateWikiPage, getWikiPage };
+
+    const outcome = await saveWikiPage(
+      service,
+      'src-1',
+      '/a.md',
+      'my edit',
+      2,
+      'tok',
+    );
+
+    expect(getWikiPage).toHaveBeenCalledWith('src-1', '/a.md', 'tok');
+    expect(outcome).toEqual({
+      status: 'conflict',
+      page: { path: '/a.md', version: 5, content: 'their edit' },
+    });
+  });
+
+  it('reports forbidden on 403 without reloading', async () => {
+    const updateWikiPage = vi.fn().mockResolvedValue(jsonResponse(403, {}));
+    const getWikiPage = vi.fn();
+    const service = { updateWikiPage, getWikiPage };
+
+    const outcome = await saveWikiPage(
+      service,
+      'src-1',
+      '/a.md',
+      'x',
+      1,
+      'tok',
+    );
+
+    expect(getWikiPage).not.toHaveBeenCalled();
+    expect(outcome).toEqual({ status: 'forbidden' });
+  });
+
+  it('reports a generic error on other failures', async () => {
+    const updateWikiPage = vi.fn().mockResolvedValue(jsonResponse(400, {}));
+    const getWikiPage = vi.fn();
+    const service = { updateWikiPage, getWikiPage };
+
+    const outcome = await saveWikiPage(
+      service,
+      'src-1',
+      '/a.md',
+      'x',
+      1,
+      'tok',
+    );
+
+    expect(outcome).toEqual({ status: 'error' });
+  });
+});
diff --git a/frontend/src/components/wikiViewerUtils.ts b/frontend/src/components/wikiViewerUtils.ts
new file mode 100644
index 00000000..080dc9c5
--- /dev/null
+++ b/frontend/src/components/wikiViewerUtils.ts
@@ -0,0 +1,92 @@
+export interface WikiPageNode {
+  path: string;
+  title?: string | null;
+  token_count?: number;
+  embed_status?: string;
+  version?: number;
+  updated_by?: string | null;
+  updated_via?: string | null;
+  updated_at?: string | null;
+  content?: string;
+}
+
+const RELATIVE_UNITS: [Intl.RelativeTimeFormatUnit, number][] = [
+  ['year', 31536000000],
+  ['month', 2592000000],
+  ['day', 86400000],
+  ['hour', 3600000],
+  ['minute', 60000],
+];
+
+export function formatRelativeTime(
+  value: string | null | undefined,
+  now: number = Date.now(),
+): string | null {
+  if (!value) return null;
+  const then = new Date(value).getTime();
+  if (Number.isNaN(then)) return null;
+  const diffMs = now - then;
+  const formatter = new Intl.RelativeTimeFormat('en', { numeric: 'auto' });
+  for (const [unit, ms] of RELATIVE_UNITS) {
+    if (Math.abs(diffMs) >= ms) {
+      return formatter.format(-Math.round(diffMs / ms), unit);
+    }
+  }
+  return formatter.format(0, 'second');
+}
+
+export function provenanceKey(
+  via?: string | null,
+  by?: string | null,
+  currentUserSub?: string | null,
+): 'you' | 'agent' | 'human' | 'unknown' {
+  if (by && currentUserSub && by === currentUserSub) return 'you';
+  if (via === 'agent') return 'agent';
+  if (via === 'human') return 'human';
+  return 'unknown';
+}
+
+export type SaveOutcome =
+  | { status: 'saved'; page: WikiPageNode | null }
+  | { status: 'conflict'; page: WikiPageNode | null }
+  | { status: 'forbidden' }
+  | { status: 'error' };
+
+interface WikiSaveService {
+  updateWikiPage: (
+    sourceId: string,
+    data: { path: string; content: string; expected_version?: number },
+    token: string | null,
+  ) => Promise<Response>;
+  getWikiPage: (
+    sourceId: string,
+    path: string,
+    token: string | null,
+  ) => Promise<Response>;
+}
+
+export async function saveWikiPage(
+  service: WikiSaveService,
+  sourceId: string,
+  path: string,
+  draft: string,
+  expectedVersion: number | undefined,
+  token: string | null,
+): Promise<SaveOutcome> {
+  const response = await service.updateWikiPage(
+    sourceId,
+    { path, content: draft, expected_version: expectedVersion },
+    token,
+  );
+  if (response.ok) {
+    const data = await response.json();
+    return { status: 'saved', page: data?.page ?? null };
+  }
+  if (response.status === 409) {
+    const refreshed = await service.getWikiPage(sourceId, path, token);
+    const data = await refreshed.json();
+    return { status: 'conflict', page: data?.page ?? null };
+  }
+  if (response.status === 403) return { status: 'forbidden' };
+  return { status: 'error' };
+}
diff --git a/frontend/src/locale/en.json b/frontend/src/locale/en.json
index abb40dc3..50ddcd43 100644
--- a/frontend/src/locale/en.json
+++ b/frontend/src/locale/en.json
@@ -106,7 +106,23 @@
       "wiki": {
         "view": "View wiki",
         "empty": "This wiki has no pages yet.",
-        "selectPage": "Select a page to view its contents."
+        "selectPage": "Select a page to view its contents.",
+        "edit": "Edit",
+        "save": "Save",
+        "cancel": "Cancel",
+        "saving": "Saving…",
+        "saveFailed": "Could not save the page. Please try again.",
+        "forbidden": "You do not have permission to edit this page.",
+        "conflict": "This page changed since you opened it and has been reloaded. Your edits are below — reapply and save again.",
+        "editPlaceholder": "Write the page in Markdown…",
+        "stamp": {
+          "editedBy": "Edited by {{who}}",
+          "agent": "agent",
+          "human": "human",
+          "you": "you",
+          "unknown": "unknown",
+          "version": "v{{version}}"
+        }
       },
       "editConfig": "Source settings",
       "shareWithTeam": "Share with team",
diff --git a/frontend/src/settings/Sources.tsx b/frontend/src/settings/Sources.tsx
index 2e2572fe..2a9df22e 100644
--- a/frontend/src/settings/Sources.tsx
+++ b/frontend/src/settings/Sources.tsx
@@ -436,6 +436,10 @@ export default function Sources({
         <WikiViewer
           docId={documentToView.id || ''}
           sourceName={documentToView.name}
+          canEdit={
+            documentToView.ownership !== 'team' ||
+            documentToView.team_access === 'editor'
+          }
           onBackToDocuments={() => setDocumentToView(undefined)}
         />
       ) : documentToView.isNested ? (
diff --git a/tests/agents/tools/test_wiki.py b/tests/agents/tools/test_wiki.py
index 8667e529..664a175c 100644
--- a/tests/agents/tools/test_wiki.py
+++ b/tests/agents/tools/test_wiki.py
@@ -39,6 +39,7 @@ class _FakeWikiRepo:
         content,
         title=None,
         updated_by=None,
+        updated_via=None,
         expected_version=None,
     ):
         key = (source_id, path)
@@ -55,6 +56,7 @@ class _FakeWikiRepo:
                     "title": title,
                     "content_hash": content_hash,
                     "updated_by": updated_by,
+                    "updated_via": updated_via,
                     "version": existing["version"] + 1,
                 }
             )
@@ -66,6 +68,7 @@ class _FakeWikiRepo:
                     "title": title,
                     "content_hash": content_hash,
                     "updated_by": updated_by,
+                    "updated_via": updated_via,
                     "version": existing["version"] + 1,
                 }
             )
@@ -78,6 +81,7 @@ class _FakeWikiRepo:
             "title": title,
             "content_hash": content_hash,
             "updated_by": updated_by,
+            "updated_via": updated_via,
             "version": 1,
             "token_count": len(content),
         }
@@ -210,6 +214,20 @@ class TestCreateView:
         reembed_mock.assert_called_once()
         rebuild_mock.assert_called_once()
 
+    def test_create_stamps_updated_via_agent(self, wiki_tool):
+        wiki_tool.execute_action("wiki_create", path="/guide.md", content="Hello")
+        stored = _FakeWikiRepo().get_by_path("src-1", "/guide.md")
+        assert stored["updated_via"] == "agent"
+
+    def test_str_replace_stamps_updated_via_agent(self, wiki_tool):
+        wiki_tool.execute_action("wiki_create", path="/g.md", content="alpha beta")
+        wiki_tool.execute_action(
+            "wiki_str_replace", path="/g.md", old_str="alpha", new_str="omega"
+        )
+        stored = _FakeWikiRepo().get_by_path("src-1", "/g.md")
+        assert stored["updated_via"] == "agent"
+        assert stored["content"] == "omega beta"
+
     def test_create_at_directory_rejected(self, wiki_tool):
         assert "directory" in wiki_tool.execute_action(
             "wiki_create", path="/docs/", content="x"
diff --git a/tests/api/user/sources/test_wiki_routes.py b/tests/api/user/sources/test_wiki_routes.py
index 89ce19d6..3c08ea90 100644
--- a/tests/api/user/sources/test_wiki_routes.py
+++ b/tests/api/user/sources/test_wiki_routes.py
@@ -162,7 +162,9 @@ class TestWikiPages:
             "wiki-list", user_id=user, type="wiki", config={"kind": "wiki"}
         )
         sid = str(src["id"])
-        WikiPagesRepository(pg_conn).upsert(sid, "/index.md", "root", updated_by=user)
+        WikiPagesRepository(pg_conn).upsert(
+            sid, "/index.md", "root", updated_by=user, updated_via="agent"
+        )
         WikiPagesRepository(pg_conn).upsert(sid, "/docs/a.md", "a", updated_by=user)
 
         with _patch_db(pg_conn), app.test_request_context(
@@ -174,6 +176,8 @@ class TestWikiPages:
         assert response.status_code == 200
         paths = {p["path"] for p in response.json["pages"]}
         assert paths == {"/index.md", "/docs/a.md"}
+        via = {p["path"]: p["updated_via"] for p in response.json["pages"]}
+        assert via["/index.md"] == "agent"
 
     def test_non_owner_without_grant_404(self, app, pg_conn):
         from application.api.user.sources.routes import WikiPages
@@ -270,6 +274,33 @@ class TestWikiPage:
             response = WikiPage().get(sid)
         assert response.status_code == 404
 
+    def test_returns_provenance_and_version(self, app, pg_conn):
+        from application.api.user.sources.routes import WikiPage
+        from application.storage.db.repositories.sources import SourcesRepository
+        from application.storage.db.repositories.wiki_pages import WikiPagesRepository
+
+        user = "u-wiki-page-provenance"
+        src = SourcesRepository(pg_conn).create(
+            "wiki", user_id=user, type="wiki", config={"kind": "wiki"}
+        )
+        sid = str(src["id"])
+        WikiPagesRepository(pg_conn).upsert(
+            sid, "/index.md", "x", updated_by=user, updated_via="agent"
+        )
+
+        with _patch_db(pg_conn), app.test_request_context(
+            f"/api/sources/{sid}/wiki/page?path=/index.md"
+        ):
+            from flask import request
+            request.decoded_token = {"sub": user}
+            response = WikiPage().get(sid)
+        assert response.status_code == 200
+        page = response.json["page"]
+        assert page["updated_via"] == "agent"
+        assert page["updated_by"] == user
+        assert page["version"] == 1
+        assert page["updated_at"] is not None
+
     def test_non_owner_without_grant_404(self, app, pg_conn):
         from application.api.user.sources.routes import WikiPage
         from application.storage.db.repositories.sources import SourcesRepository
@@ -455,8 +486,10 @@ class TestWikiPageEdit:
         assert response.status_code == 200
         assert response.json["page"]["path"] == "/notes.md"
         assert response.json["page"]["version"] is not None
+        assert response.json["page"]["updated_via"] == "human"
         page = WikiPagesRepository(pg_conn).get_by_path(sid, "/notes.md")
         assert page["content"] == "body"
+        assert page["updated_via"] == "human"
         mock_reembed.assert_called_once()
         assert mock_reembed.call_args.args[1] == "/notes.md"
         assert mock_reembed.call_args.kwargs["user"] == user
diff --git a/tests/storage/db/repositories/test_wiki_pages.py b/tests/storage/db/repositories/test_wiki_pages.py
index c611d7fc..721a135e 100644
--- a/tests/storage/db/repositories/test_wiki_pages.py
+++ b/tests/storage/db/repositories/test_wiki_pages.py
@@ -53,6 +53,26 @@ class TestUpsert:
         page = repo.upsert(sid, "/a.md", "x", updated_by="agent-1")
         assert page["updated_by"] == "agent-1"
 
+    def test_records_updated_via(self, pg_conn):
+        repo = _repo(pg_conn)
+        sid = _make_source(pg_conn)
+        page = repo.upsert(sid, "/a.md", "x", updated_via="human")
+        assert page["updated_via"] == "human"
+
+    def test_updated_via_overwritten_on_change(self, pg_conn):
+        repo = _repo(pg_conn)
+        sid = _make_source(pg_conn)
+        repo.upsert(sid, "/a.md", "v1", updated_via="agent")
+        page = repo.upsert(sid, "/a.md", "v2", updated_via="human")
+        assert page["updated_via"] == "human"
+
+    def test_updated_via_unchanged_on_identical_content(self, pg_conn):
+        repo = _repo(pg_conn)
+        sid = _make_source(pg_conn)
+        repo.upsert(sid, "/a.md", "same", updated_via="agent")
+        again = repo.upsert(sid, "/a.md", "same", updated_via="human")
+        assert again["updated_via"] == "agent"
+
 
 class TestContentHashShortCircuit:
     def test_identical_content_does_not_bump_version(self, pg_conn):
diff --git a/tests/storage/db/test_migration_0024.py b/tests/storage/db/test_migration_0024.py
new file mode 100644
index 00000000..9c215ccd
--- /dev/null
+++ b/tests/storage/db/test_migration_0024.py
@@ -0,0 +1,77 @@
+"""Migration round-trip test for 0024_wiki_pages_updated_via."""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+from sqlalchemy import text
+
+
+pytestmark = pytest.mark.integration
+
+
+def _alembic_ini() -> Path:
+    return Path(__file__).resolve().parents[3] / "application" / "alembic.ini"
+
+
+def _run_alembic(url: str, *args: str) -> None:
+    subprocess.check_call(
+        [sys.executable, "-m", "alembic", "-c", str(_alembic_ini()), *args],
+        timeout=60,
+        env={**os.environ, "POSTGRES_URI": url},
+    )
+
+
+def _alembic_heads(url: str) -> list[str]:
+    out = subprocess.check_output(
+        [sys.executable, "-m", "alembic", "-c", str(_alembic_ini()), "heads"],
+        timeout=60,
+        env={**os.environ, "POSTGRES_URI": url},
+        text=True,
+    )
+    return [line for line in out.splitlines() if line.strip()]
+
+
+def _alembic_version(conn) -> str:
+    return conn.execute(text("SELECT version_num FROM alembic_version")).scalar()
+
+
+def _column_exists(conn, table: str, column: str) -> bool:
+    row = conn.execute(
+        text(
+            "SELECT 1 FROM information_schema.columns "
+            "WHERE table_name = :t AND column_name = :c AND table_schema = 'public'"
+        ),
+        {"t": table, "c": column},
+    ).fetchone()
+    return row is not None
+
+
+_0024 = "0024_wiki_pages_updated_via"
+_0023 = "0023_wiki_pages"
+
+
+class TestMigration0024RoundTrip:
+    def test_single_head(self, pg_engine):
+        url = pg_engine.url.render_as_string(hide_password=False)
+        assert len(_alembic_heads(url)) == 1
+
+    def test_head_has_updated_via_column(self, pg_engine):
+        with pg_engine.connect() as conn:
+            assert _alembic_version(conn) >= _0024
+            assert _column_exists(conn, "wiki_pages", "updated_via")
+
+    def test_downgrade_drops_then_upgrade_restores(self, pg_engine):
+        url = pg_engine.url.render_as_string(hide_password=False)
+        _run_alembic(url, "downgrade", _0023)
+        with pg_engine.connect() as conn:
+            assert _alembic_version(conn) == _0023
+            assert not _column_exists(conn, "wiki_pages", "updated_via")
+        _run_alembic(url, "upgrade", "head")
+        with pg_engine.connect() as conn:
+            assert _alembic_version(conn) >= _0024
+            assert _column_exists(conn, "wiki_pages", "updated_via")