feat: include the days a person was seen in their data export

KNOWLEDGE_BASE.md

@@ -592,7 +592,8 @@ Sources: [issue command UI](resources/js/components/issue-command.tsx), [issue v
 
 Choose **Download JSON** in Settings → Profile to export your account data. The export includes:
 
-- profile details and preferences, including live-stream details, translation language, the last day you used /dev/null, and when you accepted the commit rules;
+- profile details and preferences, including live-stream details, translation language, and when you accepted the commit rules;
+- the days you used /dev/null (dates, not times), oldest first, and the last of them;
 - your commits and replies (including pending, rejected, and deleted entries still stored), their cached translations, polls, and your votes;
 - stars, followers and people you follow, mutes, blocks, and dismissed **Not interested** suggestions;
 - messages you sent, including links to your voice notes, and notifications;
@@ -637,7 +638,7 @@ Sources: [status transitions](app/Actions/UpdateCommitStatuses.php), [timeouts](
 
 The public **About** page describes the livestream project and lists up to 1,000 GitHub contributor accounts, excluding bots and known agents, most commits first; the list is cached for an hour and GitHub may take several hours to update its counts; when GitHub cannot be reached the page says so instead of showing the list. The **Changelog**, opened from the navigation or the side column, lists the pull requests merged into `production` on GitHub, a few days at a time. The **Brand** page at `/brand` offers the logo, wordmark, colors, typography, and wallpapers; right-clicking the logo in the navigation also copies it or links there. **Terms** and **Privacy** explain acceptable use and data handling. Public posts may be indexed or copied outside /dev/null; content and search queries can be processed by automated or AI services. Read those policies before posting sensitive information or relying on deletion to remove every external copy.
 
-To count active people and how many come back, /dev/null remembers the **days** (not the times) you were signed in and used the site or the API, and the last of them; background refreshes do not count. These days are never shown to other people and are deleted with your account; your export includes the last of them. Daily active-people numbers are kept as anonymous counts. Visitor analytics come from **Fathom**, which counts anonymously: the browser sends a `guest-visit` event once per session when you are not signed in (unless the browser is driven by a program, like a scraper's), a `signin-click` event when you tap to sign in, a `signup` event right after an account is created, and `join-link-sent`, `join-link-visit` and `join-link-signup` when a guest asks for a link by email, opens it, and signs up from it, with nothing that identifies you.
+To count active people and how many come back, /dev/null remembers the **days** (not the times) you were signed in and used the site or the API, and the last of them; background refreshes do not count. These days are never shown to other people, are included in your export, and are deleted with your account. Daily active-people numbers are kept as anonymous counts. Visitor analytics come from **Fathom**, which counts anonymously: the browser sends a `guest-visit` event once per session when you are not signed in (unless the browser is driven by a program, like a scraper's), a `signin-click` event when you tap to sign in, a `signup` event right after an account is created, and `join-link-sent`, `join-link-visit` and `join-link-signup` when a guest asks for a link by email, opens it, and signs up from it, with nothing that identifies you.
 
 Sources: [last seen tracking](app/Http/Middleware/UpdateLastSeenAt.php), [active days](app/Actions/UpdateUserLastSeenAt.php), [Fathom events](resources/js/lib/analytics.ts), [public page routes](routes/web.php), [About](resources/js/pages/about/show.tsx), [contributors](app/Queries/ContributorsQuery.php), [privacy policy](resources/js/pages/privacy/show.tsx), [terms](resources/js/pages/terms/show.tsx).
 

PRODUCT_METRICS.md

@@ -20,7 +20,7 @@ Each answers the three questions of the [data guidelines](.ai/guidelines/data.bl
 | Data | Where | Why the feature needs it | Who sees it | When it is deleted |
 |---|---|---|---|---|
 | The last day a person was seen (a date, no time) | `users.last_seen_at`, hidden | Retention and active users can't be derived from anything else: reading alone leaves no trace. Written at most once a day, without touching `updated_at`. | Admins, only as aggregates on the Growth page; the person in their export | With the account |
-| Each day a person was seen (dates, no time) | `user_active_days` (`user_id`, `seen_at`) | Retention by signup cohort, day by day (active on day 1, 7, 14), comparable with public benchmarks: `last_seen_at` only keeps the latest day, and `active_user_counts` has no user ids. Written with `last_seen_at`, the first time each person is seen in a day. | Admins, only as aggregates. Not in the person's export, which has `last_seen_at` | With the account |
+| Each day a person was seen (dates, no time) | `user_active_days` (`user_id`, `seen_at`) | Retention by signup cohort, day by day (active on day 1, 7, 14), comparable with public benchmarks: `last_seen_at` only keeps the latest day, and `active_user_counts` has no user ids. Written with `last_seen_at`, the first time each person is seen in a day. | Admins, only as aggregates; the person in their export (`active_days`) | With the account |
 | The number of people seen each day | `active_user_counts` (`seen_at`, `count`), no user ids | The daily active users history: `last_seen_at` only keeps each person's latest day, so past days can't be recomputed. Incremented the first time each person is seen in a day, so the count is exact. | Admins, on the Growth page | Never: it is an anonymous count |
 | Three anonymous events, `guest-visit`, `signin-click` and `signup` | Fathom | The conversion rate, counted on both sides by the same tool, and where in between visitors give up. No user id is sent. | Admins, through Fathom | Per Fathom's retention |
 | Three anonymous events, `join-link-sent`, `join-link-visit` and `join-link-signup` | Fathom | Whether the link a guest on a phone can ask for by email brings people back: sent when the email is asked for, when the page opens from its link (`#join-link`, then removed from the address), and when that tab then signs up, next to `signup`. Signing up leaves for GitHub, so Fathom sees the signup as a new visit; the tab remembers the link in its session storage instead. Someone who opens the link in one browser and signs up in another counts as any other signup, so it's a floor. | Admins, through Fathom | Per Fathom's retention |

app/Actions/CreateExport.php

@@ -37,6 +37,7 @@
  *     schema_version: int,
  *     exported_at: string,
  *     profile: array<string, bool|int|string|null>,
+ *     active_days: Generator<int, string>,
  *     commits: Generator<int, array<string, mixed>>,
  *     polls: Generator<int, ExportPoll>,
  *     poll_votes: Generator<int, ExportPollVote>,
@@ -105,6 +106,7 @@ public function handle(User $user): array
                 'created_at' => $user->created_at->toIso8601String(),
                 'updated_at' => $user->updated_at->toIso8601String(),
             ],
+            'active_days' => $this->activeDays($user),
             'commits' => $this->commits($user),
             'polls' => $this->polls($user),
             'poll_votes' => $this->pollVotes($user),
@@ -242,6 +244,22 @@ private function pollVotes(User $user): Generator
         }
     }
 
+    /**
+     * The days the user was seen, oldest first. They are read while the export streams, after the request asking for it
+     * was recorded, so an export that is the first visit of the day includes that day.
+     *
+     * @return Generator<int, string>
+     */
+    private function activeDays(User $user): Generator
+    {
+        /** @var LazyCollection<int, object{seen_at: string}> $days */
+        $days = DB::table('user_active_days')->where('user_id', $user->id)->oldest('seen_at')->cursor();
+
+        foreach ($days as $day) {
+            yield $day->seen_at;
+        }
+    }
+
     /**
      * @return Generator<int, string>
      */

database/migrations/2026_10_30_120000_create_user_active_days_table.php

@@ -12,8 +12,8 @@
     /**
      * Each day a person was seen, a date with no time, so retention can be read day by day for each signup cohort:
      * last_seen_at only keeps the latest day, and active_user_counts has no user ids. Only admins see it, as
-     * aggregates. DeleteUser erases the rows with the account. Everyone's last day is copied in: people already seen
-     * today aren't recorded again until tomorrow, so today would be missing for them.
+     * aggregates, and the person in their export. DeleteUser erases the rows with the account. Everyone's last day is
+     * copied in: people already seen today aren't recorded again until tomorrow, so today would be missing for them.
      */
     public function up(): void
     {

tests/Feature/Controllers/ExportControllerTest.php

@@ -126,6 +126,7 @@
             'created_at' => $user->created_at->toIso8601String(),
             'updated_at' => $user->updated_at->toIso8601String(),
         ],
+        'active_days' => [],
         'commits' => [],
         'polls' => [],
         'poll_votes' => [],
@@ -464,6 +465,31 @@
     ]);
 });
 
+it('exports the days the user was seen, oldest first, without the days of others', function (): void {
+    $user = User::factory()->create(['last_seen_at' => now()]);
+    DB::table('user_active_days')->insert([
+        ['user_id' => $user->id, 'seen_at' => '2026-10-21'],
+        ['user_id' => $user->id, 'seen_at' => '2026-10-19'],
+        ['user_id' => User::factory()->create()->id, 'seen_at' => '2026-10-20'],
+    ]);
+
+    $response = $this->actingAs($user)->get(route('export'));
+    $data = json_decode($response->streamedContent(), true, flags: JSON_THROW_ON_ERROR);
+
+    expect($data['active_days'])->toBe(['2026-10-19', '2026-10-21']);
+});
+
+it('exports today when the export is the first visit of the day', function (): void {
+    $this->travelTo(now()->setDate(2026, 10, 30)->setTime(12, 0));
+    $user = User::factory()->create(['last_seen_at' => '2026-10-29']);
+    DB::table('user_active_days')->insert(['user_id' => $user->id, 'seen_at' => '2026-10-29']);
+
+    $response = $this->actingAs($user)->get(route('export'));
+    $data = json_decode($response->streamedContent(), true, flags: JSON_THROW_ON_ERROR);
+
+    expect($data['active_days'])->toBe(['2026-10-29', '2026-10-30']);
+});
+
 it('exports the devices approved for the app, oldest first', function (): void {
     $user = User::factory()->create();
     $older = Device::factory()->for($user)->create(['name' => 'devnull on iPad', 'approved_at' => now()->subWeek(), 'last_used_at' => now()->subDay()]);