adeelahmad · Oct 19, 2026 · Oct 19, 2026
diff --git a/changelog.d/timeline-who-reacted.md b/changelog.d/timeline-who-reacted.md
@@ -0,0 +1,2 @@
+Hovering a reaction on the timeline says who gave it ("You, Sam and 3 others"), and the API, MCP and the page
+carry up to five names of the others who gave each one.
diff --git a/docs/requirements.md b/docs/requirements.md
@@ -260,7 +260,7 @@ request, to another check that proves the same thing; loosening a requirement or
 | Everything that happens is kept as W3C Activity Streams activities, read by agents through the API, MCP and the assistant | [test_events.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/domain/test_events.py) `test_activities_have_one_shape`; [test_activities.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_activities.py) `test_the_timeline_lists_new_assets_newest_first`, `test_agents_read_the_timeline_too`; [test_news_feed_source.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_news_feed_source.py) `test_a_news_feed_as_a_source` |
 | Ask the assistant about a timeline item from the item (its button, or `a` on its line), in the chat beside the page, with the item's id, line and fields as what the question is about | [timeline-ui.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-ui.test.tsx) `asking about an item hands the page chat its id, line and fields, by button or the a key`; [page-chat.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/page-chat.test.tsx) `opens with what a page's own Ask about this hands it, and sends it as the highlighted part` |
 | The Timeline page and Latest on Home, marking what you've seen | [test_timeline_marks.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_timeline_marks.py) `test_marks_are_set_cleared_and_filter_the_timeline`; [timeline-ui.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-ui.test.tsx) `Home's Latest card lists what you haven't reviewed` |
-| Reactions and comments on timeline activities, shared by everyone who sees them, through the API, MCP and the page | [test_timeline_social.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_timeline_social.py) `test_reactions_are_shared_counted_and_taken_back`, `test_comments_on_an_activity_are_a_thread_everyone_who_sees_it_joins`, `test_comments_on_a_logged_activity_follow_its_audience`, `test_agents_react_and_comment_too`; [timeline-ui.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-ui.test.tsx) `reactions and comments: a line sums its items', a 👍 goes to the server, and Enter sends a comment` |
+| Reactions and comments on timeline activities, shared by everyone who sees them, each reaction saying who gave it, through the API, MCP and the page | [test_timeline_social.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_timeline_social.py) `test_reactions_are_shared_counted_and_taken_back`, `test_comments_on_an_activity_are_a_thread_everyone_who_sees_it_joins`, `test_comments_on_a_logged_activity_follow_its_audience`, `test_agents_react_and_comment_too`, `test_a_reaction_names_who_else_gave_it_earliest_first_up_to_five`; [timeline-social-model.test.ts](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-social-model.test.ts) `a reaction's hover says who gave it: you first, then up to five names, then how many more`; [timeline-ui.test.tsx](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-ui.test.tsx) `reactions and comments: a line sums its items', a 👍 goes to the server, and Enter sends a comment` |
 | Tagging @lens in a comment on the timeline or an asset gets the agent's answer in the thread, as the person who tagged it, with every change waiting for their approval, off with `ai.answer_comments` | [test_comment_agent.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_comment_agent.py) `test_the_agent_answers_a_tagged_comment_in_the_thread`, `test_without_a_model_or_within_a_used_up_budget_the_reply_says_so`; [timeline-social-model.test.ts](https://github.com/adeelahmad/lense/blob/main/nextjs-frontend/__tests__/timeline-social-model.test.ts) `the agent's reply links its addresses` |
 | Automations act on the stream, on a schedule, at a time or when their own webhook is called | [test_automation_runs.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/domain/test_automation_runs.py) `test_each_new_activity_runs_each_automation_it_matches_once`, `test_a_schedule_runs_its_automation_when_its_timer_fires`, `test_a_call_to_a_webhook_runs_its_automation`; [test_timer_triggers.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/domain/test_timer_triggers.py) `test_an_at_trigger_fires_once_then_reads_done` |
 | They test conditions, then tell you, ask the model or the agent, use a tool, call a web address with sealed credentials, run Lens work, or change assets and notes | [test_automation_runs.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/domain/test_automation_runs.py) `test_the_if_limits_and_dry_runs`; [test_actions_messages.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_actions_messages.py) `test_notify_tells_me_in_my_chat_app`; [test_actions_ai.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_actions_ai.py) `test_ask_model_answers_in_text_or_as_the_fields_a_schema_names`, `test_ask_agent_works_on_what_happened_and_saves_the_conversation`, `test_call_tool_reads_as_the_person_and_changes_only_by_asking_them`; [test_actions_web.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_actions_web.py) `test_credentials_in_headers_are_sealed_to_the_automation_and_the_host_and_never_shown`; [test_actions_run.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_actions_run.py) `test_run_workflow_queues_it_on_the_asset_as_the_automation`, `test_run_pipeline_processes_the_asset_again`; [test_actions_lens.py](https://github.com/adeelahmad/lense/blob/main/fastapi_backend/tests/api/test_actions_lens.py) `test_set_field_is_kept_in_the_assets_history_by_the_automation`, `test_write_note_writes_a_page_adds_to_a_things_page_or_notes_an_asset` |

diff --git a/docs/timeline.md b/docs/timeline.md
@@ -92,7 +92,8 @@ them, and each one is an activity of its own, so an automation (or an agent) can
 
 - **Reactions** come from a palette, 👍 ❤️ 🎉 👀 😂 😮 😢 🙏. An opened item shows its reactions as chips with how
   many gave each (yours are highlighted; a click on one of yours takes it back) and a **React** button with the
-  palette. A closed line sums its items' reactions, and a line of several shows them with "3 comments". Every new
+  palette. Hovering a chip says who gave it: "You, Sam and 3 others", you first, then up to five others by name,
+  earliest first. A closed line sums its items' reactions, and a line of several shows them with "3 comments". Every new
   reaction is a `reaction.added` activity (noisy, so the timeline leaves it out unless asked for by kind), by the
   person, with the activity it is on as its object.
 - **Comments** open from the comment count on an opened item (or **Comment** when there are none): the threads with
@@ -103,7 +104,7 @@ them, and each one is an activity of its own, so an automation (or an agent) can
 - Comments and reactions on an activity meant for one person (`lens.audience` owner) stay with that person, as the
   activity does.
 - `POST /api/v1/activities/{id}/react` with `{"emoji": "👍"}` (and `"on": false` to take it back) answers the
-  reactions on it now, `[{emoji, count, mine}]`; `GET`, `POST`, `PATCH` and `DELETE /api/v1/activities/{id}/comments`
+  reactions on it now, `[{emoji, count, mine, who}]` (`who`: up to five of the others who gave it, by name); `GET`, `POST`, `PATCH` and `DELETE /api/v1/activities/{id}/comments`
   are the thread, as [comments on a resource](api.md#comments) are. `GET /api/v1/activities` carries everyone's
   reactions on the page in `reactions` and each item's comment count in `comments`, by id.
 
@@ -257,6 +258,6 @@ per source page; they go when the person is removed. Nothing of this costs a mod
 - Saved filter views.
 - 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).
+- Editing and resolving comments from the timeline (the API has both).
 - 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/api/mcp_tools.py b/fastapi_backend/app/api/mcp_tools.py
@@ -3897,7 +3897,8 @@ def mute_activities(
     "React to an activity",
     "Put an emoji on an activity of the timeline, as on a post in a feed, for the person you act for: one of 👍 ❤️ 🎉 👀 "
     "😂 😮 😢 🙏; on false takes theirs back. Everyone who sees the activity sees the reactions, and a new one is a "
-    "reaction.added activity automations can act on. The answer is the reactions on it now (emoji, count, mine). "
+    "reaction.added activity automations can act on. The answer is the reactions on it now (emoji, count, mine, and "
+    "who else gave it). "
     "Needs a token with the write scope.",
     Arg("id", "string", "the activity's id, like create-recording-7", required=True, max_length=120),
     Arg("emoji", "string", "the emoji, from the palette", required=True, enum=event_reactions.EMOJIS),

diff --git a/fastapi_backend/app/domain/event_reactions.py b/fastapi_backend/app/domain/event_reactions.py
@@ -15,10 +15,11 @@
 
 import hashlib
 
-from . import events, store
+from . import events, events_content, store
 
 R = store.R
 EMOJIS = ("👍", "❤️", "🎉", "👀", "😂", "😮", "😢", "🙏")
+WHO = 5  # how many of the others who gave a reaction are named on it
 LABELS = {
     "👍": "thumbs up",
     "❤️": "heart",
@@ -84,33 +85,52 @@ def check(emoji):
     return emoji
 
 
-def _tally(rows, account):
-    """{activity: [{emoji, count, mine}]} from rows of (activity, account, emojis), each list in the palette's order."""
+def _tally(db, rows, account):
+    """{activity: [{emoji, count, mine, who}]} from rows of (activity, account, emojis, at), each list in the palette's
+    order; `who` names up to WHO of the others who gave it, earliest first (then by account, for the same moment);
+    `mine` says the person asking did."""
     counts: dict[str, dict[str, int]] = {}
     mine: dict[str, set[str]] = {}
-    for r in rows:
+    gave: dict[str, dict[str, list]] = {}
+    for r in sorted(rows, key=lambda r: (str(r.get("at") or ""), r["account"] if isinstance(r.get("account"), int) else 0)):
         for e in r.get("emojis") or []:
             if e not in EMOJIS:
                 continue
             counts.setdefault(r["activity"], {})[e] = counts.get(r["activity"], {}).get(e, 0) + 1
             if account is not None and r.get("account") == account:
                 mine.setdefault(r["activity"], set()).add(e)
-    return {aid: [{"emoji": e, "count": n[e], "mine": e in mine.get(aid, set())} for e in EMOJIS if e in n] for aid, n in counts.items()}
+            else:
+                gave.setdefault(r["activity"], {}).setdefault(e, []).append(r.get("account"))
+    names = events_content.actors(db, [(a, None) for g in gave.values() for ids in g.values() for a in ids[:WHO]])
+    return {
+        aid: [
+            {
+                "emoji": e,
+                "count": n[e],
+                "mine": e in mine.get(aid, set()),
+                "who": [names[(a, None)]["name"] for a in gave.get(aid, {}).get(e, [])[:WHO]],
+            }
+            for e in EMOJIS
+            if e in n
+        ]
+        for aid, n in counts.items()
+    }
 
 
 def of(db, account, ids):
-    """{activity id: [{emoji, count, mine}]} of everyone's reactions on these activities, in one query; an activity
-    with none isn't in it. `mine`: the person asking gave that one."""
+    """{activity id: [{emoji, count, mine, who}]} of everyone's reactions on these activities, in one query (and one
+    for the names); an activity with none isn't in it. `mine`: the person asking gave that one; `who`: up to WHO
+    names of the others who did, earliest first."""
     ids = sorted({i for i in ids if isinstance(i, str)})
     if not ids:
         return {}
-    rows = db.rows("SELECT activity, account, emojis FROM event_reaction WHERE activity IN $ids", ids=ids)
-    return _tally(rows, account)
+    rows = db.rows("SELECT activity, account, emojis, at FROM event_reaction WHERE activity IN $ids", ids=ids)
+    return _tally(db, rows, account)
 
 
 def react(db, account, activity, emoji, on=True):
     """Give the emoji to the activity (or take it back with `on` false), for `account`; the reactions on it after,
-    [{emoji, count, mine}]. Whether anything changed is the second value, so the caller logs it only then."""
+    [{emoji, count, mine, who}]. Whether anything changed is the second value, so the caller logs it only then."""
     emoji = check(emoji)
     row = db.one("SELECT emojis FROM $r", r=_ref(account, activity))
     have = [e for e in (row or {}).get("emojis") or [] if e in EMOJIS]

diff --git a/fastapi_backend/app/schemas/activities.py b/fastapi_backend/app/schemas/activities.py
@@ -61,11 +61,12 @@ class ActivityMark(ResponseModel):
 
 
 class Reaction(ResponseModel):
-    """One emoji on an activity: how many people gave it, and whether you did."""
+    """One emoji on an activity: how many people gave it, whether you did, and who else did."""
 
     emoji: str
     count: int
     mine: bool = False
+    who: list[str] = Field(default_factory=list, description="up to five of the others who gave it, by name, earliest first")
 
 
 class ActivityPage(ResponseModel):

diff --git a/fastapi_backend/tests/api/test_timeline_social.py b/fastapi_backend/tests/api/test_timeline_social.py
@@ -32,20 +32,29 @@ def test_reactions_are_shared_counted_and_taken_back(client, db, cfg, folder):
     assert client.get(URL, headers=hr).json()["reactions"] == {}
     # the admin and the viewer both 👍 the first episode; the viewer ❤️s it too
     got = client.post(f"{URL}/{pods1}/react", json={"emoji": "👍"}, headers=hr).json()
-    assert got == {"reactions": [{"emoji": "👍", "count": 1, "mine": True}]}
+    assert got == {"reactions": [{"emoji": "👍", "count": 1, "mine": True, "who": []}]}
     client.post(f"{URL}/{pods1}/react", json={"emoji": "👍"}, headers=hv)
     got = client.post(f"{URL}/{pods1}/react", json={"emoji": "❤️"}, headers=hv).json()["reactions"]
-    assert got == [{"emoji": "👍", "count": 2, "mine": True}, {"emoji": "❤️", "count": 1, "mine": True}]
-    # everyone sees the same counts on the page, each with their own `mine`
+    assert got == [
+        {"emoji": "👍", "count": 2, "mine": True, "who": ["root"]},
+        {"emoji": "❤️", "count": 1, "mine": True, "who": []},
+    ]
+    # everyone sees the same counts on the page, each with their own `mine`, and who else gave each
     page = client.get(URL, params=ASSETS, headers=hr).json()
     assert list(page["reactions"]) == [pods1]
-    assert page["reactions"][pods1] == [{"emoji": "👍", "count": 2, "mine": True}, {"emoji": "❤️", "count": 1, "mine": False}]
+    assert page["reactions"][pods1] == [
+        {"emoji": "👍", "count": 2, "mine": True, "who": ["vi"]},
+        {"emoji": "❤️", "count": 1, "mine": False, "who": ["vi"]},
+    ]
     assert client.get(URL, params=ASSETS, headers=hv).json()["reactions"][pods1][1]["mine"] is True
     # giving one again changes nothing; taking it back drops it, and the row goes when nothing is left
     assert client.post(f"{URL}/{pods1}/react", json={"emoji": "👍"}, headers=hr).json()["reactions"][0]["count"] == 2
     assert db.one("SELECT count() AS n FROM event_reaction GROUP ALL")["n"] == 2
     got = client.post(f"{URL}/{pods1}/react", json={"emoji": "👍", "on": False}, headers=hr).json()["reactions"]
-    assert got == [{"emoji": "👍", "count": 1, "mine": False}, {"emoji": "❤️", "count": 1, "mine": False}]
+    assert got == [
+        {"emoji": "👍", "count": 1, "mine": False, "who": ["vi"]},
+        {"emoji": "❤️", "count": 1, "mine": False, "who": ["vi"]},
+    ]
     assert db.values("SELECT VALUE account FROM event_reaction") == [env["vi"]]
     # each new reaction is a reaction.added activity on the stream (noisy: asked for by kind), by the person
     liked = client.get(URL, params={"kinds": "reaction.added"}, headers=hr).json()["items"]
@@ -159,7 +168,7 @@ def test_agents_react_and_comment_too(client, db, cfg, folder):
     pods1, pods2, call = env["ids"]
     hv = env["hv"]
     got = tool(client, hv, "react_to_activity", id=pods1, emoji="🎉")
-    assert got == {"reactions": [{"emoji": "🎉", "count": 1, "mine": True}]}
+    assert got == {"reactions": [{"emoji": "🎉", "count": 1, "mine": True, "who": []}]}
     assert tool(client, hv, "react_to_activity", id=pods1, emoji="🎉", on=False) == {"reactions": []}
     assert "not found" in tool_error(client, hv, "react_to_activity", id=call, emoji="🎉")
     c = tool(client, hv, "comment_on_activity", id=pods1, text="Listen to this one")
@@ -171,3 +180,14 @@ def test_agents_react_and_comment_too(client, db, cfg, folder):
     assert "text is required" in tool_error(client, hv, "comment_on_activity", id=pods1, text=" ")
     assert tool(client, hv, "timeline", kinds=["asset.added"])["comments"] == {pods1: 2}
     assert event_reactions.check("👍") == "👍"
+
+
+def test_a_reaction_names_who_else_gave_it_earliest_first_up_to_five(db, cfg, folder):
+    [first, *_] = [f"create-recording-{i}" for i in seed(db, cfg, folder)]
+    people = [make_user(db, f"p{n}@x.io", f"person password {n}") for n in range(7)]
+    for p in people:
+        event_reactions.react(db, p, first, "🎉")
+    [mine] = event_reactions.of(db, people[0], [first])[first]
+    assert mine == {"emoji": "🎉", "count": 7, "mine": True, "who": ["p1", "p2", "p3", "p4", "p5"]}
+    [theirs] = event_reactions.of(db, None, [first])[first]
+    assert theirs["mine"] is False and theirs["who"] == ["p0", "p1", "p2", "p3", "p4"]
diff --git a/nextjs-frontend/__tests__/timeline-social-model.test.ts b/nextjs-frontend/__tests__/timeline-social-model.test.ts
@@ -1,4 +1,4 @@
-import { applyReaction, commentsLabel, linked, sumReactions } from "@/components/timeline/social-model";
+import { applyReaction, commentsLabel, linked, reactedBy, sumReactions } from "@/components/timeline/social-model";
 
 test("a reaction moves the count by one and keeps the palette's order", () => {
   const list = [{ emoji: "❤️", count: 2, mine: false }];
@@ -23,14 +23,30 @@ test("a line sums its items' reactions, yours when you gave it on any", () => {
       [],
     ]),
   ).toEqual([
-    { emoji: "👍", count: 3, mine: true },
-    { emoji: "🎉", count: 1, mine: false },
+    { emoji: "👍", count: 3, mine: true, who: [] },
+    { emoji: "🎉", count: 1, mine: false, who: [] },
   ]);
+  expect(
+    sumReactions([
+      [{ emoji: "👍", count: 2, mine: false, who: ["Sam", "Vi"] }],
+      [{ emoji: "👍", count: 1, mine: false, who: ["Sam"] }],
+    ]),
+  ).toEqual([{ emoji: "👍", count: 3, mine: false, who: ["Sam", "Vi"] }]);
   expect(commentsLabel(0)).toBe("");
   expect(commentsLabel(1)).toBe("1 comment");
   expect(commentsLabel(4)).toBe("4 comments");
 });
 
+test("a reaction's hover says who gave it: you first, then up to five names, then how many more", () => {
+  expect(reactedBy({ emoji: "👍", count: 1, mine: true, who: [] })).toBe("You");
+  expect(reactedBy({ emoji: "👍", count: 2, mine: true, who: ["Sam"] })).toBe("You and Sam");
+  expect(reactedBy({ emoji: "👍", count: 3, mine: false, who: ["Sam", "Vi"] })).toBe("Sam, Vi and 1 other");
+  expect(reactedBy({ emoji: "👍", count: 9, mine: true, who: ["A", "B", "C", "D", "E"] })).toBe(
+    "You, A, B, C, D, E and 3 others",
+  );
+  expect(reactedBy({ emoji: "👍", count: 2, mine: false })).toBe("2 others");
+});
+
 test("the agent's reply links its addresses", () => {
   expect(linked("Done.\nDecide in Lens: Write the note\nhttps://lens.local/approvals?id=3 (soon)")).toEqual([
     { text: "Done.\nDecide in Lens: Write the note\n" },
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Hovering a reaction on the timeline says who gave it ("You, Sam and 3 others"), and the API, MCP and the page
		carry up to five names of the others who gave each one.