adeelahmad · Oct 18, 2026 · Oct 18, 2026
diff --git a/changelog.d/timeline-open-item.md b/changelog.d/timeline-open-item.md
@@ -0,0 +1,3 @@
+The timeline opens one item by its id (`/timeline?item=<id>`), above the rest with its details and actions and a way
+back. A comment or a reaction on an item, and an approval's "because", now link to that item rather than to the
+timeline as a whole.
diff --git a/docs/requirements.md b/docs/requirements.md
@@ -207,6 +207,7 @@ request, to another check that proves the same thing; loosening a requirement or
 | Muting a source, a person or a kind on the timeline, for good or until a time, for the person alone, with nothing deleted; through the API, MCP, the assistant (asking first after outside text) and the page | [test_timeline_mutes.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_timeline_mutes.py) `test_a_mute_hides_an_actor_or_a_kind_for_the_person_alone`, `test_agents_mute_too_and_the_assistant_asks_first_after_outside_text`; jest [timeline-ui.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-ui.test.tsx) `muting a source takes everything from it out, lists it as muted, and Undo or the chip brings it back`, `the menu beside Mute snoozes a source for a day, or mutes the item's kind` |
 | An asset moved to another namespace is `asset.moved`, a Move seen where it is now, and a sensor a person pauses, ignores, resumes or sets back to new is `sensor.changed`, an Update with the status it had before, seen in its namespace or by admins; a change that changes nothing logs nothing | [test_timeline_verbs.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_timeline_verbs.py) `test_moving_an_asset_is_a_move_seen_where_it_is_now`, `test_switching_a_sensor_is_an_update_with_what_it_was` |
 | An opened timeline item shows what it caused, the runs it started of the automations the person manages and the approvals those asked for, with Approve and Decline on waiting ones; `GET /activities/{id}/caused`, `approvals?activity=`, MCP `activity_caused` and the assistant | [test_timeline_caused.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_timeline_caused.py) `test_an_item_lists_what_it_caused_and_the_waiting_approval_is_decided_there`, `test_agents_read_what_an_item_caused_too`; jest [timeline-ui.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-ui.test.tsx) `an opened item shows what it caused, and a waiting approval is approved there` |
+| One timeline item by its id in the address (`/timeline?item=<id>`), opened above the timeline with its actions and a way back, which is where a comment on an item, a reaction and an approval's "because" link | jest [timeline-ui.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-ui.test.tsx) `the address can name one item, opened above the timeline, with a way back`; [test_timeli
10000
ne_social.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_timeline_social.py) `test_comments_on_a_logged_activity_follow_its_audience` |
 | Every entity's own page at `/wiki/<namespace>/<Name>` | [test_entities.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_entities.py) `test_wiki_addresses`; [wiki-page.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/wiki-page.test.tsx); [journeys.mjs](https://github.com/adeelahmad/lense/blob/main/ci/clicks/journeys.mjs) `entity-find` |
 | Entities, topics and people edited and merged from their lists, the graph or an asset, with Undo instead of a confirm | [test_entities.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/domain/test_entities.py) `test_suggestions_and_merge_undo`; [entities-curate.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/entities-curate.test.tsx); [topics-curate.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/topics-curate.test.tsx); [recording-entities-edit.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/recording-entities-edit.test.tsx); [journeys.mjs](https://github.com/adeelahmad/lense/blob/main/ci/clicks/journeys.mjs) `entity-merge`, `graph-merge`, `speaker-rename` |
 | Names get their real types (people, places, organisations, events, works) by rules, without a model; older Terms are typed on upgrade | [test_name_types.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/domain/test_name_types.py) `test_names_get_the_type_their_words_give`, `test_analysis_types_people_places_and_events`, `test_the_upgrade_types_the_old_terms_and_keeps_what_people_chose` |

diff --git a/docs/timeline.md b/docs/timeline.md
@@ -48,6 +48,10 @@ unless you ask for them by kind.
   automation (what it did or caused). Filters live in the address, so a view can be linked, and the last set you used
   comes back the next time you open the page in this browser. **Clear** drops them all.
 - On a phone the list is one column and the filters open in a sheet from **Filters**.
+- One item: `/timeline?item=<id>` (an activity's id, like `create-recording-7`) opens that item above the timeline,
+  with its details, marks, reactions, comments and actions, and **Back to the timeline** under it. That is the link
+  a comment on an item, a reaction and an approval's "because" give to the item they are about, and the link an
+  agent gives a person to an item it read with `timeline`. One you can't see says "No such item".
 
 ### Reviewing
 
@@ -254,6 +258,5 @@ per source page; they go when the person is removed. Nothing of this costs a mod
 - Marks on activities whose rows are gone (an event log entry past `events.keep_days`, a deleted asset) stay until
   the person is removed; a tidy could drop them. Reactions and comments on such activities likewise.
 - Who gave each reaction, on hover; editing and resolving comments from the timeline (the API has both).
-- A `comment.added` on an activity links to the timeline, not yet to the item itself.
 - The agent's reply in a thread is plain text with links; the answer's excerpts could open at their moment, as in
   chat. Tagging a namespace's own assistant by its name, with its memory.
diff --git a/fastapi_backend/app/domain/approvals.py b/fastapi_backend/app/domain/approvals.py
@@ -104,7 +104,7 @@ def _why(event):
             "kind": event.get("kind"),
             "summary": event.get("summary"),
             "published": event.get("published"),
-            "url": (event.get("object") or {}).get("url"),
+            "url": (event.get("object") or {}).get("url") or f"/timeline?item={event['id']}",
         }
     )
 

diff --git a/fastapi_backend/app/domain/event_reactions.py b/fastapi_backend/app/domain/event_reactions.py
@@ -42,6 +42,7 @@
             "properties": {
                 "id": {"type": "string", "title": "The activity it is on", "description": "lens:activity/<its id>"},
                 "name": {"type": "string", "title": "That activity's summary"},
+                "url": {"type": "string", "title": "Link", "description": "the item on the timeline"},
                 "emoji": {"type": "string", "title": "The emoji", "enum": list(EMOJIS)},
                 "activity": {"type": "string", "title": "The activity's id"},
             },
@@ -58,6 +59,7 @@
             "type": "Activity",
             "id": "lens:activity/create-recording-7",
             "name": "Work Gmail received “Parents' evening”",
+            "url": "/timeline?item=create-recording-7",
             "emoji": "👍",
             "activity": "create-recording-7",
         },
@@ -139,6 +141,7 @@ def log(db, a, actor, emoji):
             "type": "Activity",
             "id": f"lens:activity/{a['id']}",
             "name": a.get("summary") or a["id"],
+            "url": f"/timeline?item={a['id']}",
             "emoji": emoji,
             "activity": a["id"],
         },

diff --git a/fastapi_backend/app/domain/events_content.py b/fastapi_backend/app/domain/events_content.py
@@ -1261,7 +1261,7 @@ def _comment_activities(db, rows):
                 "type": "Note",
                 "id": f"lens:comment/{r['id']}",
                 "content": _text(r.get("text"), CONTENT_MAX) or "",
-                "url": f"/resources/{r.get('recording')}" if r.get("recording") is not None else "/timeline",
+                "url": f"/resources/{r.get('recording')}" if r.get("recording") is not None else f"/timeline?item={r.get('activity')}",
                 "inReplyTo": f"lens:comment/{r['parent']}" if reply else None,
                 "quote": _text(r.get("quote")),
                 "t0": _num(r.get("t0")),

diff --git a/fastapi_backend/tests/api/test_timeline_social.py b/fastapi_backend/tests/api/test_timeline_social.py
@@ -137,7 +137,7 @@ def test_comments_on_a_logged_activity_follow_its_audience(client, db, cfg, fold
     assert client.get(URL, params={"kinds": "test_thing.happened"}, headers=hv).json()["comments"] == {shared: 1}
     added = client.get(URL, params={"kinds": "comment.added"}, headers=hv).json()["items"][0]
     assert added["target"] == {"type": "Activity", "id": f"lens:activity/{shared}", "name": "Lens noted x"}
-    assert added["object"]["url"] == "/timeline"
+    assert added["object"]["url"] == f"/timeline?item={shared}"  # the item itself, opened on the timeline
     # a comment on an activity only its owner sees is seen by the owner alone, as a comment and on the stream
     assert client.get(f"{URL}/{private}/comments", headers=hv).status_code == 404
     client.post(f"{URL}/{private}/comments", json={"text": "Just us"}, headers=hr)

diff --git a/nextjs-frontend/__tests__/timeline-ui.test.tsx b/nextjs-frontend/__tests__/timeline-ui.test.tsx
@@ -23,6 +23,7 @@ jest.mock("@/app/openapi-client", () => ({
     listActivityMutes: jest.fn(),
     muteActivities: jest.fn(),
     activityCaused: jest.fn(),
+    getActivity: jest.fn(),
   },
   Chats: { decideApproval: jest.fn() },
 }));
@@ -139,6 +140,10 @@ beforeEach(() => {
   m(Activities.listActivityComments).mockReturnValue(ok([COMMENT]));
   m(Activities.listActivityMutes).mockReturnValue(ok({ mutes: [] }));
   m(Activities.activityCaused).mockReturnValue(ok({ runs: [], approvals: [] }));
+  m(Activities.getActivity).mockImplementation(({ path }) => {
+    const a = ITEMS.find((x) => x.id === path.activity_id);
+    return a ? ok(a) : Promise.reject(new Error("not found"));
+  });
   m(Activities.muteActivities).mockImplementation(({ body }) =>
     ok({
       mutes: body.on
@@ -511,3 +516,20 @@ test("the menu beside Mute snoozes a source for a day, or mutes the item's kind"
   expect(Date.parse(until) - Date.now()).toBeGreaterThan(23 * 3_600_000);
   expect(await screen.findByText("Muted Work Gmail for a day")).toBeInTheDocument();
 });
+
+test("the address can name one item, opened above the timeline, with a way back", async () => {
+  search = "item=u1";
+  wrap(<TimelinePage />);
+  const  screen.findByRole("region", { name: "This item" });
+  expect(m(Activities.getActivity)).toHaveBeenCalledWith(expect.objectContaining({ path: { activity_id: "u1" } }));
+  // opened already: its details and actions are there, and the whole timeline still lists below
+  expect(await within(one).findByRole("button", { name: "Hide" })).toBeInTheDocument();
+  expect(within(one).getByRole("link", { name: "Adeel received “Mail u1”" })).toHaveAttribute("href", "/resources/u1");
+  expect(within(one).getByRole("link", { name: "Back to the timeline" })).toHaveAttribute("href", "/timeline");
+  expect(within(await screen.findByRole("list", { name: "Timeline" })).getAllByTestId("timeline-row")).toHaveLength(2);
+  expect(replace).not.toHaveBeenCalled();
+  // one that isn't there, or not yours, says so
+  search = "item=nope";
+  wrap(<TimelinePage />);
+  expect(await screen.findByText("No such item")).toBeInTheDocument();
+});
diff --git a/nextjs-frontend/components/approvals/inbox-card.tsx b/nextjs-frontend/components/approvals/inbox-card.tsx
@@ -75,7 +75,7 @@ export function InboxCard({
   const expires = expiresLine(a.expires_at);
   const lines = paramLines(a.intent?.params);
   const why = a.why;
-  const whyHref = why?.url || (why?.activity ? `/timeline?q=${encodeURIComponent(why.summary ?? "")}` : null);
+  const whyHref = why?.url || (why?.activity ? `/timeline?item=${encodeURIComponent(why.activity)}` : null);
 
   return (
     <div

diff --git a/nextjs-frontend/components/timeline/one-item.tsx b/nextjs-frontend/components/timeline/one-item.tsx
@@ -0,0 +1,78 @@
+"use client";
+
+import { useQuery } from "@tanstack/react-query";
+import { ArrowLeft } from "lucide-react";
+import Link from "next/link";
+import { useState, type ComponentProps } from "react";
+
+import { Activities } from "@/app/openapi-client";
+import type { StreamActivity } from "@/app/openapi-client/types.gen";
+import { TimelineRow } from "@/components/timeline/item";
+import { group, type Activity } from "@/components/timeline/model";
+import { EmptyState, Skeleton } from "@/components/ui/states";
+import { data, useApiClient } from "@/lib/api/browser";
+
+/** One activity by its id (GET /api/v1/activities/{id}), for `/timeline?item=<id>`: the link a comment, a reaction
+ * or an approval gives to the item it is about. */
+export function useOneItem(id: string) {
+  const client = useApiClient();
+  return useQuery({
+    queryKey: ["timeline-item", id],
+    queryFn: () => data(Activities.getActivity({ client, path: { activity_id: id } })) as Promise<StreamActivity>,
+    enabled: !!id,
+    staleTime: 10_000,
+  });
+}
+
+type RowProps = ComponentProps<typeof TimelineRow>;
+
+/** The item the address names, opened above the timeline, with the same marks, reactions, comments and actions as
+ * any line, and a way back to the whole timeline. */
+export function OneItem({
+  id,
+  a,
+  error,
+  back,
+  ...row
+}: {
+  id: string;
+  a: Activity | undefined;
+  error: Error | null;
+  /** Where "Back to the timeline" goes. */
+  back: string;
+} & Pick<
+  RowProps,
+  | "namespaces"
+  | "labels"
+  | "markOf"
+  | "onMark"
+  | "onHide"
+  | "onMute"
+  | "reactionsOf"
+  | "commentsOf"
+  | "caused"
+  | "social"
+>) {
+  const [open, setOpen] = useState(true);
+  const g = a ? group([a])[0] : null;
+  return (
+    <section aria-label="This item" className="flex flex-col gap-2">
+      <div className="flex flex-wrap items-center gap-2 text-[12.5px] text-fg-secondary">
+        <span className="font-semibold">This item</span>
+        <Link href={back} className="inline-flex items-center gap-1 text-fg-accent hover:underline">
+          <ArrowLeft className="size-3.5" aria-hidden />
+          Back to the timeline
+        </Link>
+      </div>
+      {error ? (
+        <EmptyState title="No such item">{error.message}</EmptyState>
+      ) : g ? (
+        <ul className="flex flex-col rounded-md border border-border bg-surface px-3">
+          <TimelineRow group={g} open={open}  => setOpen((o) => !o)} focused={false} {...row} />
+        </ul>
+      ) : (
+        <Skeleton className="h-12" aria-label={`Loading ${id}`} />
+      )}
+    </section>
+  );
+}
diff --git a/nextjs-frontend/components/timeline/timeline-page.tsx b/nextjs-frontend/components/timeline/timeline-page.tsx
@@ -10,6 +10,7 @@ import { askAbout } from "@/components/page-chat/page-chat-model";
 import { Caused } from "@/components/timeline/caused";
 import { FiltersBar, type Actor } from "@/components/timeline/filters";
 import { TimelineRow, groupMark, type MuteOpts } from "@/components/timeline/item";
+import { OneItem, useOneItem } from "@/components/timeline/one-item";
 import {
   askQuote,
   filterCount,
@@ -83,6 +84,7 @@ export function TimelinePage() {
   const params = useSearchParams();
   const qs = params.toString();
   const filters = useMemo(() => fromParams(new URLSearchParams(qs)), [qs]);
+  const itemId = params.get("item") ?? "";
   const { namespaces } = useArchive();
   const phone = useMediaQuery("(max-width: 767px)");
   const [sheet, setSheet] = useState(false);
@@ -106,6 +108,7 @@ export function TimelinePage() {
   );
 
   const timeline = useTimeline(filters);
+  const >
   const kinds = useKinds();
   const pages = timeline.data?.pages;
   const query = useMemo(() => toQuery(filters), [filters]);
@@ -342,6 +345,32 @@ export function TimelinePage() {
           ))}
         </div>
       )}
+      {itemId && (
+        <OneItem
+          id={itemId}
+          a={one.data}
+          error={one.error as Error | null}
+          namespaces={{ ...Object.fromEntries((namespaces ?? []).map((n) => [String(n.id), n.name])), ...nsNames }}
+          labels={labels}
+          markOf={marks.of}
+          >
+          >
+          >
+          reactionsOf={reactions.of}
+          commentsOf={counts.of}
+          caused={(a) => <Caused a={a} />}
+          social={(a) => (
+            <Social
+              a={a}
+              reactions={reactions.of(a.id)}
+               on) => reactions.react(a.id, emoji, on)}
+              comments={counts.of(a.id)}
+              bump={counts.bump}
+            />
+          )}
+          back={pathname}
+        />
+      )}
       {phone && (
         <Drawer open={sheet}  title="Filters" width={360}>
           <div className="p-4">{bar(true)}</div>