From 6ec0b6ceb6046d200c2f010056f5cde13af85d7d Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Sun, 8 Nov 2026 08:02:34 -0500
Subject: [PATCH] B87: saved copies of trail pages

Save a Copy of This Page (File menu, right-click) and Save a copy on a page
card save the page as an MHTML file named by its SHA-256, with its text, on
this computer. Keep copies in a trail's menu saves one for each page that
becomes a card. The card shows the newest copy and opens it after checking
its hash. Trail files list copies; they are sent only when ticked, in a
folder beside the file, and checked when the file is opened.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011V7Bv7WZ9Q92MZoNWYwevQ
---
 .github/workflows/ci.yml     |   4 +-
 core/trail-file.js           |  24 +++-
 core/trail.js                |  33 +++++-
 docs/02-roadmap-backlog.md   |   2 +-
 docs/03-architecture.md      |   8 ++
 docs/05-changelog.md         |   1 +
 docs/26-trail-file-format.md |   2 +
 main.js                      | 210 ++++++++++++++++++++++++++++++++++-
 package.json                 |   3 +-
 preload.js                   |   4 +
 renderer/app.js              |  22 +++-
 renderer/canvas.js           |  40 ++++++-
 renderer/index.html          |   1 +
 renderer/styles.css          |   5 +
 test/copies-demo.js          |  70 ++++++++++++
 test/e2e/53-saved-copies.js  | 161 +++++++++++++++++++++++++++
 test/e2e/README.md           |   1 +
 17 files changed, 577 insertions(+), 14 deletions(-)
 create mode 100644 test/copies-demo.js
 create mode 100644 test/e2e/53-saved-copies.js

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 551c77f..1aaa93e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,7 +30,7 @@ jobs:
           (cd test/e2e/site && python3 -m http.server 8765 >/dev/null 2>&1 &)
           sleep 1
           mkdir -p e2e-out
-          for t in 01-basics 03-rules-and-fast-results 04-find-zoom-history 05-research-session 09-playback-limit 12-pip-bookmarks-adblock 13-ask-ai 15-agents-mcp 16-research-agent 17-talk 18-redteam 19-browser-basics 20-first-run-and-help 21-rules-editor 22-ui-refresh 23-beta-survey 24-mosaic-pick 25-video-loop 26-gestures-tour 27-privacy-visible 28-ask-across-tabs 29-blocker-onpage 30-tab-focus-sleep 31-passwords 32-passwords-more 33-sidebar-chrome 34-command-bar 35-frames-tabs 36-trail-tabs 37-threads 38-trail-share 39-trail-open 40-share-link 41-survey-newtab 42-trail-canvas 43-canvas-tools 44-share-open 45-mosaic-gallery 48-canvas-media 49-trail-rename-delete 50-provenance 51-trail-recall 52-media-moments; do
+          for t in 01-basics 03-rules-and-fast-results 04-find-zoom-history 05-research-session 09-playback-limit 12-pip-bookmarks-adblock 13-ask-ai 15-agents-mcp 16-research-agent 17-talk 18-redteam 19-browser-basics 20-first-run-and-help 21-rules-editor 22-ui-refresh 23-beta-survey 24-mosaic-pick 25-video-loop 26-gestures-tour 27-privacy-visible 28-ask-across-tabs 29-blocker-onpage 30-tab-focus-sleep 31-passwords 32-passwords-more 33-sidebar-chrome 34-command-bar 35-frames-tabs 36-trail-tabs 37-threads 38-trail-share 39-trail-open 40-share-link 41-survey-newtab 42-trail-canvas 43-canvas-tools 44-share-open 45-mosaic-gallery 48-canvas-media 49-trail-rename-delete 50-provenance 51-trail-recall 52-media-moments 53-saved-copies; do
             echo "::group::$t"
             xvfb-run -a node test/e2e/$t.js "$PWD/e2e-out" 2>&1 | tee e2e-out/$t.log
             status=${PIPESTATUS[0]}
@@ -71,7 +71,7 @@ jobs:
           (cd test/e2e/site && python -m http.server 8765 --bind 127.0.0.1 >/dev/null 2>&1 &)
           sleep 2
           mkdir -p e2e-out
-          for t in 01-basics 05-research-session 19-browser-basics 20-first-run-and-help 22-ui-refresh 23-beta-survey 24-mosaic-pick 25-video-loop 26-gestures-tour 27-privacy-visible 28-ask-across-tabs 29-blocker-onpage 30-tab-focus-sleep 31-passwords 32-passwords-more 33-sidebar-chrome 34-command-bar 35-frames-tabs 36-trail-tabs 37-threads 38-trail-share 39-trail-open 40-share-link 41-survey-newtab 42-trail-canvas 43-canvas-tools 44-share-open 45-mosaic-gallery 48-canvas-media 49-trail-rename-delete 50-provenance 51-trail-recall 52-media-moments; do
+          for t in 01-basics 05-research-session 19-browser-basics 20-first-run-and-help 22-ui-refresh 23-beta-survey 24-mosaic-pick 25-video-loop 26-gestures-tour 27-privacy-visible 28-ask-across-tabs 29-blocker-onpage 30-tab-focus-sleep 31-passwords 32-passwords-more 33-sidebar-chrome 34-command-bar 35-frames-tabs 36-trail-tabs 37-threads 38-trail-share 39-trail-open 40-share-link 41-survey-newtab 42-trail-canvas 43-canvas-tools 44-share-open 45-mosaic-gallery 48-canvas-media 49-trail-rename-delete 50-provenance 51-trail-recall 52-media-moments 53-saved-copies; do
             echo "::group::$t"
             node test/e2e/$t.js "$PWD/e2e-out" 2>&1 | tee e2e-out/$t.log
             status=${PIPESTATUS[0]}
diff --git a/core/trail-file.js b/core/trail-file.js
index 2d9bab1..942e3c4 100644
--- a/core/trail-file.js
+++ b/core/trail-file.js
@@ -516,6 +516,12 @@ function merge(base, incoming, answers = {}) {
 
 const FORMAT_V2 = 2;
 const SIZE_V2 = { page: [260, 200], video: [260, 220], capture: [260, 210], report: [260, 240], question: [260, 170], note: [260, 150], voice: [260, 170], search: [260, 140], media: [300, 240], moment: [280, 190] };
+// Saved copies (B87): "7 Nov 2026 21:40".
+const copyTime = (t) => {
+  const d = new Date(t);
+  return `${d.getDate()} ${MONTH_NAMES[d.getMonth()]} ${d.getFullYear()} ${String(d.getHours()).padStart(2, "0")}:${String(d.getMinutes()).padStart(2, "0")}`;
+};
+const MONTH_NAMES = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
 // Media moments (B88): "41:12" and back, in seconds.
 const clockOf = (t) => {
   t = Math.max(0, Math.round(Number(t) || 0));
@@ -695,7 +701,9 @@ function timelineLine(sess, byId) {
 
 // options: { by, at (ms or ISO), note, startHere (card id), timeline (true),
 // openTabs: [card ids] (none by default) }
-function toTrailMd(snap, { by = "", at = Date.now(), note, startHere, timeline = true, openTabs = [] } = {}) {
+// copies (B87): { folder, include: [sha256] } — saved copies sent beside the
+// file, in that folder. Copies not sent are still listed, as kept by the sender.
+function toTrailMd(snap, { by = "", at = Date.now(), note, startHere, timeline = true, openTabs = [], copies = null } = {}) {
   const t = snap.trail || {};
   const cards = (snap.cards || []).filter(sendable).map(forFile);
   const byId = new Map(cards.map((c) => [c.id, c]));
@@ -708,7 +716,10 @@ function toTrailMd(snap, { by = "", at = Date.now(), note, startHere, timeline =
   L.push("---", `# ${oneLine(t.name) || "Trail"}`, "");
   if (oneLine(words)) L.push(oneLine(words), "");
   if (start) L.push(`**Start here:** [${mdText(cardTitle(start))}](#${start.id})`, "");
-  const block = (c) => L.push(cardHeading(c), layoutComment(c), ...cardBody(c), "");
+  const sent = new Set(copies?.include || []);
+  const copyLines = (c) =>
+    (c.copies || []).map((x) => `Copy: ${x.atText || copyTime(x.at)} · SHA-256 ${x.sha256}${copies?.folder && sent.has(x.sha256) ? ` · [saved copy](${encodeURI(`${copies.folder}/${x.sha256}.mhtml`)})` : ""}`);
+  const block = (c) => L.push(cardHeading(c), layoutComment(c), ...cardBody(c), ...(c.kind === "page" ? copyLines(c) : []), "");
   const placed = new Set();
   for (const g of groups) {
     L.push(`## ${oneLine(g.label) || "New group"}`, `<!-- group:${g.id} at:${Math.round(g.x)},${Math.round(g.y)} size:${Math.round(g.w)}x${Math.round(g.h)}${g.resolved ? " resolved" : ""} -->`, "");
@@ -889,7 +900,14 @@ function readCard(raw) {
     case "page": {
       const kw = b.find((l) => /^Keywords:/.test(l));
       const reached = b.find((l) => /^Reached: /.test(l));
-      const ex = b.filter((l) => l !== kw && l !== reached);
+      // Saved copies (B87): "Copy: <time> · SHA-256 <hash>[ · [saved copy](folder/<hash>.mhtml)]"
+      const copyRows = b.filter((l) => /^Copy: .+ · SHA-256 [0-9a-f]{64}/.test(l));
+      for (const l of copyRows) {
+        const m = l.match(/^Copy: (.+?) · SHA-256 ([0-9a-f]{64})(?: · \[saved copy\]\((\S+)\))?$/);
+        if (!m) continue;
+        (c.copies = c.copies || []).push({ atText: m[1], sha256: m[2], ...(m[3] ? { file: decodeURI(m[3]) } : {}) });
+      }
+      const ex = b.filter((l) => l !== kw && l !== reached && !copyRows.includes(l));
       if (ex.length) c.excerpt = ex.join(" ");
       c.keywords = kw ? kw.replace(/^Keywords:\s*/, "").split(/,\s*/).filter(Boolean) : [];
       if (reached) {
diff --git a/core/trail.js b/core/trail.js
index 862c0a7..cbd1a9f 100644
--- a/core/trail.js
+++ b/core/trail.js
@@ -24,7 +24,7 @@ const GROUP_SIDE = 24; // group padding around its cards: sides and bottom
 const GROUP_TOP = 48; // and top, where the name sits
 const SESSION_GAP_MS = 30 * 60 * 1000; // a gap of more than 30 minutes starts a new session
 const ENGAGED_MS = 20 * 1000; // the 20-second rule (doc 23); a starting guess
-const EVENT_TYPES = new Set(["opened", "bounced", "captured", "asked", "reported", "noted", "placed", "removed", "linked", "unlinked", "grouped", "renamed", "resolved", "moved", "edited"]);
+const EVENT_TYPES = new Set(["opened", "bounced", "captured", "asked", "reported", "noted", "placed", "removed", "linked", "unlinked", "grouped", "renamed", "resolved", "moved", "edited", "copied"]);
 const CARD_KINDS = new Set(["page", "video", "capture", "report", "question", "note", "voice", "search", "media", "moment"]);
 const LINE_KINDS = new Set(["nav", "auto", "you", "suggested"]);
 const LINE_LABELS = new Set(["", "supports", "contradicts", "answers", "raises"]);
@@ -372,6 +372,7 @@ class TrailStore {
           createdAt: trail.createdAt,
           lastAt: trail.lastAt,
           readonly: trail.readonly,
+          keepCopies: Boolean(trail.keepCopies),
           from: trail.from || "",
           note: trail.note || "",
           startHere: trail.startHere || "",
@@ -543,6 +544,36 @@ class TrailStore {
     if (card && source && !source.removed) this.link(id, source.id, card.id, { kind: "auto", label: "captured from", at });
     return card;
   }
+  // ---- saved copies (B87) ----
+  // A copy of a page card's page, saved on this computer (main.js keeps the
+  // file, named by its SHA-256). The card lists its copies, newest last.
+  addCopy(id, url, { sha256, bytes = 0, at = this.now() } = {}) {
+    const d = this.get(id);
+    const c = url && this.pageCard(id, url);
+    if (!d || d.trail.readonly || !c || c.removed || isSensitiveUrl(url) || !/^[0-9a-f]{64}$/.test(String(sha256))) return null;
+    c.copies = c.copies || [];
+    const have = c.copies.find((x) => x.sha256 === sha256);
+    if (have) return have; // the page has not changed since that copy
+    const copy = { at, sha256, bytes: Math.max(0, Math.round(Number(bytes) || 0)) };
+    c.copies.push(copy);
+    this.event(id, { type: "copied", card: c.id, at, data: { url, sha256 } });
+    this.save(id);
+    return copy;
+  }
+  // Every copy any trail names (for cleaning up files no trail needs).
+  copyHashes() {
+    const out = new Set();
+    for (const t of [...this.index.order, ...this.deletedIds()]) for (const c of this.load(t)?.data.cards || []) for (const x of c.copies || []) out.add(x.sha256);
+    return out;
+  }
+  // The trail setting: keep a copy of each page that becomes a card.
+  setKeepCopies(id, on) {
+    const d = this.get(id);
+    if (!d || d.trail.readonly) return null;
+    d.trail.keepCopies = Boolean(on);
+    this.save(id);
+    return d.trail.keepCopies;
+  }
   // ---- media moments (B88) ----
   // A section of a video or audio page, a to b in seconds, with the caption
   // text shown during it when the site had captions. It goes next to its
diff --git a/docs/02-roadmap-backlog.md b/docs/02-roadmap-backlog.md
index 4b6f6b3..f1ba23f 100644
--- a/docs/02-roadmap-backlog.md
+++ b/docs/02-roadmap-backlog.md
@@ -108,7 +108,7 @@ Effort: XS under 1 hour, S half a day, M 1-2 days, L 3+ days. Finding IDs (C1, K
 | B84 | 4 | Show a trail's history (`shareLog`, already recorded): who added which pages and threads, and when | P1 | XS | Not started. Covered by Replay (B110) for canvas trails |
 | B85 | 4 | "Searched, nothing found" entry: a reply type in a thread that records a search that found nothing | P2 | XS | Not started |
 | B86 | 4 | Check before creating a share link: warn when a trail has pages naming private people or showing social posts; trails private by default. Add a shared trail file with a prompt injection to the B58 red-team set | P1 | S | Not started |
-| B87 | 4 | Save a copy of each trail page (offered, not forced) with a SHA-256 hash and the time; kept on the computer, sent only through share links | P1 | M | Not started |
+| B87 | 4 | Save a copy of each trail page (offered, not forced) with a SHA-256 hash and the time; kept on the computer, sent only through share links | P1 | M | Built 2026-11-08 (PR #71): "Save a Copy of This Page" (File menu, right-click) and "Save a copy" on a selected page card, plus "Keep copies" per trail (off by default); MHTML named by its SHA-256 with its text beside it; the card says "Copy · 8 Nov 10:05" and opens the copy after checking its hash; sharing sends copies only when ticked, in a folder beside the trail file (Sven, 2026-11-08: button + trail setting, MHTML + text, card mark + send when ticked). Electron build only. Tests `test:copies`, e2e `53-saved-copies` |
 | B88 | 4 | Media moments: one key saves start and end time, transcript text if available, and the link, then pauses playback; reuses the B70 loop range. "ID at 41:12" requests in threads | P1 | M | Built 2026-11-07 (PR #68): ⌘⇧K marks the start, then the end (with a loop set, one press saves the loop), and ⌘⇧J saves the last 30 seconds (Sven chose both, 2026-11-07); a moment card next to the page's card with the captions shown during it; times can be changed on the card; Play opens the page at the start and loops the range; Ask for ID makes a question "ID at 41:12?" that the moment raises. Electron build only. Tests `test:moment`, e2e `52-media-moments` |
 | B89 | 4 | Search past trails by what the person remembers: order ("after the Discogs page"), time, thread, keyword | P1 | M | Built 2026-11-07 (PR #67): an "In your trails" group in the CommandBar and the canvas search bar's list; local rules only, no AI; picking a result goes to its card, or its timeline row (Sven, 2026-11-07). Electron build only. Tests `test:recall`, e2e `51-trail-recall` |
 | B90 | 4 | Close tabs into a trail with a reason (to read, reference, reminder). Possible answer to B75 | P2 | S | Not started |
diff --git a/docs/03-architecture.md b/docs/03-architecture.md
index 56b6836..2dec67f 100644
--- a/docs/03-architecture.md
+++ b/docs/03-architecture.md
@@ -274,6 +274,14 @@ The same core modules run in the built-in extension of the Chromium build (`brow
 - **Rename:** `rename(id, name)` records a `renamed` event; `applySession` now does the same when a session's name changes, so renames through research:\* are events too.
 - **Channels:** `trail:rename-id` (id, name; refused for read-only trails; the current trail goes through research:\*), `trail:delete` (closes the trail's tabs first, then `changeTrail` if it was current; returns `{deleted, name, tabs, current}`), `trail:restore` (via `changeTrail`).
 - **Switcher** (`renderer/app.js`): each trail row is `.sb-menu-row` with the item and a "…" button; the actions row (`.sb-menu-acts`) holds Rename and Delete…, then the question with Delete trail and Keep. `#sb-undo` under the menu shows Undo for 10 s. Keys on a trail in the menu: F2 renames, Delete or Backspace asks to delete, → reaches "…". Over a page the field is typed in the sidebar's layer (`chrome-overlay.html`); the real field does not save on losing focus there, and Enter or Esc come back through `overlayEvent`.
+## Saved copies (B87)
+
+- **Files:** `userData/copies/<sha256>.mhtml` (`webContents.savePage(…, "MHTML")`, then renamed to its SHA-256) and `<sha256>.txt` (`readableTextScript`). MHTML differs on every save (date, part boundaries), so a copy whose text equals the newest copy's text is dropped and the newest one stands (`sameAsLastCopy`). `cleanCopies` at start-up deletes files that no trail names (`TrailStore.copyHashes`, after `purge`).
+- **Main:** `copyTab(tab)` (File menu, page right-click, Keep copies after `engagePage`) and `copyUrl(trail, url)` (a card with no tab: a hidden, sandboxed window, 20 s limit, refused if it lands on a sign-in page). `openCopy(sha)` checks the SHA-256 before opening the file in a tab. `trailSnapshot` adds `here` (the file is on this computer) to each copy.
+- **Store:** page cards have `copies: [{ at, sha256, bytes }]`, newest last, each recorded as a `copied` event (not shown in the timeline). `trail.keepCopies` is the trail setting.
+- **Sharing:** `trail:share-save` with `copies` writes the files to "<name> copies" beside the trail file and passes `{ folder, include }` to `toTrailMd`. `takeCopies(file, data)` runs before `importFile`: only files inside the trail file's folder, ending in .mhtml, under 100 MB; a match is copied in, a mismatch is marked `changed`.
+- **Window:** the card's `.cv-card-copy` line, the selection bar's "Save a copy", "Keep copies: On/Off" in the switcher's trail actions, "Saved copies of pages" in the share sheet.
+
 ## Media moments (B88)
 
 - **Page script** `momentScript(op, secs)` (`core/page-scripts.js`), run in every frame until one has media: `state`, `start` (marks the time and collects the captions on screen every 400 ms: text tracks' active cues, else `.ytp-caption-segment`, `.vp-captions` and similar), `end` (the mark to now, with what it collected, else the text-track cues in that range; pauses), `last` (the last n seconds with their cues; pauses), `loop` (the B70 loop's range; pauses), `cancel`. `loopScript("range", 60, { a, b })` seeks to a, plays and loops a–b, for video or audio.
diff --git a/docs/05-changelog.md b/docs/05-changelog.md
index 83284bd..1d93cf3 100644
--- a/docs/05-changelog.md
+++ b/docs/05-changelog.md
@@ -4,6 +4,7 @@ Newest first. Commit hashes refer to the git history inside the delivered zip fi
 
 | Date | Commit | Change |
 | --- | --- | --- |
+| 2026-11-08 | (PR #71) | **B87: saved copies of trail pages.** Offered, never forced. **Save a Copy of This Page** (File menu, or right-click a page) and **Save a copy** on a selected page card (with no tab open, the page loads out of sight) save the page as it looks now as one MHTML file, named by its SHA-256, with its readable text beside it, on this computer (userData/copies). The page becomes a card if it wasn't. Saving again when the page's text hasn't changed keeps the one copy ("This page hasn't changed since its copy of 8 Nov 10:05."). **Keep copies** in a trail's … menu (off by default) saves a copy of each page that becomes a card in that trail. The card shows "Copy · 8 Nov 10:05" (and "· 2 copies" when there are more); clicking it opens the copy in a tab after checking its SHA-256, and a copy that changed on disk is not opened. Sign-in, account and payment pages (B66), private tabs and opened (read-only) trails get no copies. Sharing: trail files list each copy ("Copy: 8 Nov 2026 10:05 · SHA-256 …"); copies are sent only when **Saved copies of pages** is ticked in the share sheet, as files in a folder "<file name> copies" beside the trail file, linked from the file (doc 26). Opening such a file keeps each copy whose SHA-256 matches and marks one that doesn't as changed. Copy files no trail names are deleted at start-up, after deleted trails are purged. New `TrailStore.addCopy`, `copyHashes`, `setKeepCopies` (event `copied`), channels `trail:copy-save`, `trail:copy-open`, `trail:keep-copies`. Electron build only. Tests: `test/copies-demo.js` (`npm run test:copies`, in `test:unit`, 4 checks), new `test/e2e/53-saved-copies.js` (20 checks, in CI). |
 | 2026-11-07 | (PR #68) | **B88: media moments.** On a page with video or audio, ⌘⇧K (View → Save Moment: Start / End, or right-click a video) marks the start and playback goes on; pressing it again marks the end, saves the moment and pauses. With a loop set (B70), one press saves the loop's range. ⌘⇧J (Save the Last 30 Seconds) saves the 30 seconds up to now and pauses. A moment is a card next to its page's card (the page becomes a card if it wasn't), with a grey "moment from" line, the start and end, and the captions shown during it when the site had captions (text tracks, YouTube and Vimeo captions; up to 1,200 characters). On the card: click the times to change them ("41:12–42:30"), **Play** opens the page at the start and loops the range, and **Ask for ID** adds a question "ID at 41:12?" that the moment raises, for others to answer. The timeline shows "Moment 41:12–42:30 · title", Replay says "You saved a moment of “…”, 41:12 to 42:30.", trail files carry moment cards (doc 26), and search past trails (B89) finds moments by their captions or the word "moment". Private tabs and opened (read-only) trails save no moments. New `TrailStore.momentCard` and `momentTimes` (event `edited`), `momentScript` in `core/page-scripts.js`, `loopScript` op `range`, channels `tab:moment`, `trail:moment-play`, `trail:moment-times`, `trail:moment-id`. Electron build only. Also: the B62 row now says Mac signing is done and the passkey entitlement is waiting on Apple. Tests: `test/moment-demo.js` (`npm run test:moment`, in `test:unit`, 7 checks), new `test/e2e/52-media-moments.js` (17 checks, in CI). |
 | 2026-11-07 | (PR #67) | **B89: search past trails by what you remember.** Typing in the CommandBar (⌘L, ⌘T) or the canvas search bar now also lists up to four matches from all your trails under "In your trails", each with why it matched, the day and the trail ("after “Memex – Encyclopedia” · Tue 3 Nov · Reading list"). NODE reads, with its own rules and no AI: words (titles, sites, addresses, keywords, excerpts, question and note text, replies, group names); times (today, yesterday, this morning, last night, Tuesday, last Tuesday, this week, last week, this month, last month, in October, 3 days ago, 2 weeks ago, a few days ago, recently); order (after X, before X, around X, next to X: the pages just after or before X in the same trail); kinds (video, song, podcast, question, thread, note, search, image, screenshot); and a trail ("in Rye breads"). Pages that stayed in the timeline are found too. Picking a result switches to its trail and selects its card with a short ring (opacity only), or, for a page that never became a card, shows the canvas and marks its row in the sidebar's timeline. In the canvas search list, cards on the current trail are left out, since the search bar already marks them. Nothing leaves the computer. New `core/recall.js` (no platform imports), channel `trail:recall`. Electron build only. Tests: `test/recall-demo.js` (`npm run test:recall`, in `test:unit`, 9 checks, including 6,000 pages in 40 trails in about 30 ms), new `test/e2e/51-trail-recall.js` (13 checks, in CI). |
 | 2026-11-06 | (PR #65) | **B83: trail provenance.** NODE records how each page in a trail was reached: a link on another page (its site), a web search (the query; pages opened from Brave, Google, DuckDuckGo, Bing and other results pages, or after a search typed in NODE), an address you typed (address bar, CommandBar, canvas), NODE's suggestions (with the keyword or search they came from), the research agent, or the site moving on to the next video or track by itself (no click or key press in the tab for 5 s while the page before was playing). Separately, a page is marked "played by NODE" when NODE's autoplay started its video or audio with no click just before. Each page card shows one line under its title, such as "Suggested by NODE for “levain”" or "Link from reddit.com"; NODE's and the site's picks are violet. Replay captions say it ("NODE suggested “…” for “…”, and you opened it.", "youtube.com played “…” next by itself.", "The research agent found “…”."), and visits that stayed in the timeline keep it too. Trail files add `Reached: …` to page cards and `(timeline only · …)` to timeline items (doc 26); a file opened by someone else keeps it. Single-page sites that change address (YouTube's next video) now start a new page for the trail. New `core/provenance.js` (no platform imports; the window and the Chromium canvas page load it for the card line). `tab:create` and `tab:navigate` take an optional `via`. Electron build only for now. Tests: `test/provenance-demo.js` (`npm run test:provenance`, in `test:unit`), new `test/e2e/50-provenance.js` (14 checks, in CI). |
diff --git a/docs/26-trail-file-format.md b/docs/26-trail-file-format.md
index a190516..8c4a780 100644
--- a/docs/26-trail-file-format.md
+++ b/docs/26-trail-file-format.md
@@ -46,6 +46,8 @@ Status: draft, Nov 5 2026 (media cards added the same day, B114). Replaces the v
 | media, screenshot or a file from the computer | `### Screenshot: Title` (or `Image:`, `Video:`, `Audio:`) | `From [site](page address)` if any, then `The file stayed on the sender's computer.` |
 | moment | `### [Title](page address) · moment 41:12–42:30` | `> captions shown during the moment`, if the site had captions |
 
+Saved copies (B87, added 2026-11-08) keep `node-trail: 2`: a page card can end with one line per copy, oldest first: `Copy: 8 Nov 2026 10:05 · SHA-256 <64 hex digits>`. When the sender ticks "Saved copies" in the share sheet, the copies go as `<sha256>.mhtml` files in a folder `<file name> copies` beside the trail file, and each line adds ` · [saved copy](<folder>/<sha256>.mhtml)`. Without that choice the lines only say a copy exists. When the file is opened, each copy in the folder whose SHA-256 matches its line is kept on the reader's computer; one that doesn't match is marked changed and never opened.
+
 Moment cards (B88, added 2026-11-07) keep `node-trail: 2`: a section of a video or audio page, start and end in the heading (`m:ss` or `h:mm:ss`), the captions as one quoted line (at most 1,200 characters). A "moment from" line joins the page's card to the moment. An "ID at 41:12?" request is an ordinary question card with a "raises" line from the moment.
 
 Media cards (B114, added 2026-11-05) keep `node-trail: 2`: the layout comment adds `media:image`, `media:screenshot`, `media:video` or `media:audio`. The file never carries the media itself or the sender's Library id. Media saved from the web links to where it came from (`src`), without tracking codes, so the reader's NODE shows a large preview from there (the image, or a video or audio player). A screenshot links only to its page. Readers that don't know media cards see a normal Markdown image or link.
diff --git a/main.js b/main.js
index aa734d5..074169e 100644
--- a/main.js
+++ b/main.js
@@ -576,6 +576,7 @@ function openTrails() {
   // Trails deleted last time (B115) are gone for good now.
   const purged = trailStore.purge();
   if (purged.length) log().info(`trails: deleted ${purged.length}`);
+  cleanCopies(trailStore.copyHashes());
   trailStore.current();
   return new ResearchStore(sessionStorageOver(trailStore));
 }
@@ -637,7 +638,161 @@ function engagePage(tab, reason) {
   const p = tab?.page;
   if (!p || p.engaged || tab.private || !trailStore) return null;
   p.engaged = true;
-  return placeCard(p.trail || currentTrail(), p.url, { title: tab.view.webContents.getTitle(), from: p.from, via: p.via, played: p.played, reason });
+  const card = placeCard(p.trail || currentTrail(), p.url, { title: tab.view.webContents.getTitle(), from: p.from, via: p.via, played: p.played, reason });
+  // B87: a trail set to keep copies saves one when a page becomes a card.
+  if (card && reason !== "copy" && trailStore.get(p.trail || currentTrail())?.trail.keepCopies) setTimeout(() => tab.page === p && copyTab(tab, { quiet: true }), 1500);
+  return card;
+}
+
+// ---- Saved copies (B87) ----
+// A copy of a page as it looked, saved as one MHTML file named by its
+// SHA-256, with its readable text beside it (for search), in
+// userData/copies. Offered, never forced: "Save a copy" on a tab or a page
+// card, or the trail setting "Keep copies". Copies stay on this computer
+// unless the person ticks "Include saved copies" when sharing a trail file.
+const copiesDir = () => path.join(app.getPath("userData"), "copies");
+const copyFile = (sha) => path.join(copiesDir(), `${sha}.mhtml`);
+const sha256Of = (buf) => require("crypto").createHash("sha256").update(buf).digest("hex");
+async function saveCopyOf(wc) {
+  fs.mkdirSync(copiesDir(), { recursive: true });
+  const tmp = path.join(copiesDir(), `tmp-${process.pid}-${Date.now().toString(36)}.mhtml`);
+  await wc.savePage(tmp, "MHTML");
+  const buf = fs.readFileSync(tmp);
+  const sha = sha256Of(buf);
+  if (fs.existsSync(copyFile(sha))) fs.rmSync(tmp, { force: true });
+  else fs.renameSync(tmp, copyFile(sha));
+  let text = "";
+  try {
+    const page = await runInPage(wc, readableTextScript(200000));
+    text = [page?.title, page?.text].filter(Boolean).join("\n\n");
+    if (text) fs.writeFileSync(path.join(copiesDir(), `${sha}.txt`), text);
+  } catch (_) {}
+  return { sha256: sha, bytes: buf.length, text };
+}
+// MHTML files differ each time (their date and part boundaries), so a page
+// is "unchanged" when its text is the same as in its newest copy.
+function sameAsLastCopy(trail, url, text) {
+  const last = trailStore.pageCard(trail, url)?.copies?.at(-1);
+  if (!last || !text) return null;
+  try {
+    return fs.readFileSync(path.join(copiesDir(), `${last.sha256}.txt`), "utf8") === text ? last : null;
+  } catch (_) {
+    return null;
+  }
+}
+function dropCopyFiles(sha) {
+  if (trailStore.copyHashes().has(sha)) return;
+  for (const ext of ["mhtml", "txt"]) fs.rmSync(path.join(copiesDir(), `${sha}.${ext}`), { force: true });
+}
+function copyRefused(url, trail) {
+  if (!/^https?:/i.test(url || "")) return "Only web pages can be saved as copies.";
+  if (isSensitiveUrl(url)) return "Sign-in, account and payment pages are never saved.";
+  if (trailStore.get(trail)?.trail.readonly) return "This trail is read only. Save it as a new trail to save copies.";
+  return "";
+}
+const copyWhen = (t) => new Date(t).toLocaleString("en-CA", { day: "numeric", month: "short", hour: "2-digit", minute: "2-digit", hour12: false });
+async function copyTab(tab, { quiet = false } = {}) {
+  if (!tab || tab.sleeping) return null;
+  if (tab.private) return quiet ? null : void sendUi("notice", { message: "Private tabs are in no trail, so their pages can't be saved as copies." });
+  const wc = tab.view.webContents;
+  const url = tab.page?.url || wc.getURL();
+  const trail = tab.page?.trail || tab.trail || currentTrail();
+  const why = copyRefused(url, trail);
+  if (why) return quiet ? null : void sendUi("notice", { message: why });
+  engagePage(tab, "copy"); // the copy belongs to the page's card
+  let saved;
+  try {
+    saved = await saveCopyOf(wc);
+  } catch (err) {
+    log().warn(`copy: ${err.message}`);
+    return quiet ? null : void sendUi("notice", { message: "The copy could not be saved." });
+  }
+  const same = sameAsLastCopy(trail, url, saved.text);
+  if (same) {
+    dropCopyFiles(saved.sha256);
+    return quiet ? same : (sendUi("notice", { message: `This page hasn't changed since its copy of ${copyWhen(same.at)}.` }), same);
+  }
+  research.saveNow();
+  const copy = trailStore.addCopy(trail, url, { sha256: saved.sha256, bytes: saved.bytes });
+  research.reload();
+  if (copy) sendUi("trail-changed", { trail });
+  if (!quiet && copy) sendUi("notice", { message: `Saved a copy of this page (${copyWhen(copy.at)}). It stays on this computer.` });
+  return copy;
+}
+// A page card with no open tab: the page loads in a hidden window first.
+async function copyUrl(trail, url) {
+  const why = copyRefused(url, trail);
+  if (why) return void sendUi("notice", { message: why });
+  const w = new BrowserWindow({ show: false, width: 1280, height: 900, webPreferences: { sandbox: true, contextIsolation: true, nodeIntegration: false } });
+  try {
+    await Promise.race([w.loadURL(url), new Promise((_, no) => setTimeout(() => no(new Error("timed out")), 20000))]);
+    await new Promise((r) => setTimeout(r, 1500)); // late content
+    if (copyRefused(w.webContents.getURL(), trail)) throw new Error("redirected to a page that is never saved");
+    const saved = await saveCopyOf(w.webContents);
+    const same = sameAsLastCopy(trail, url, saved.text);
+    if (same) {
+      dropCopyFiles(saved.sha256);
+      sendUi("notice", { message: `This page hasn't changed since its copy of ${copyWhen(same.at)}.` });
+      return same;
+    }
+    research.saveNow();
+    const copy = trailStore.addCopy(trail, url, { sha256: saved.sha256, bytes: saved.bytes });
+    research.reload();
+    if (copy) {
+      sendUi("trail-changed", { trail });
+      sendUi("notice", { message: `Saved a copy of this page (${copyWhen(copy.at)}). It stays on this computer.` });
+    }
+    return copy;
+  } catch (err) {
+    log().warn(`copy: ${err.message}`);
+    sendUi("notice", { message: "The page could not be loaded to save a copy." });
+    return null;
+  } finally {
+    if (!w.isDestroyed()) w.destroy();
+  }
+}
+// Copy files no trail names any more go (after deleted trails are purged).
+function cleanCopies(keep) {
+  try {
+    for (const f of fs.readdirSync(copiesDir())) {
+      const sha = f.replace(/\.(mhtml|txt)$/, "");
+      if (/^tmp-/.test(f) || (/^[0-9a-f]{64}$/.test(sha) && !keep.has(sha))) fs.rmSync(path.join(copiesDir(), f), { force: true });
+    }
+  } catch (_) {}
+}
+// Save a copy of a page card's page: from its open tab in this trail if
+// there is one, else in a hidden window.
+ipcMain.handle("trail:copy-save", async (_e, cardId) => {
+  const trail = currentTrail();
+  const c = trailStore?.card(trail, String(cardId));
+  if (c?.kind !== "page" || !c.url) return null;
+  const base = (u) => String(u || "").split("#")[0];
+  const tab = [...tabs.values()].find((t) => !t.private && t.trail === trail && base(t.page?.url || t.view.webContents.getURL()) === base(c.url));
+  return tab ? copyTab(tab) : copyUrl(trail, c.url);
+});
+ipcMain.handle("trail:copy-open", (_e, sha) => openCopy(String(sha)));
+ipcMain.handle("trail:keep-copies", (_e, id, on) => {
+  const trail = String(id || currentTrail());
+  const out = trailStore?.setKeepCopies(trail, Boolean(on));
+  sendUi("trail-changed", { trail });
+  return out ?? null;
+});
+// Opens a saved copy in a tab, after checking it still has its hash.
+function openCopy(sha) {
+  if (!/^[0-9a-f]{64}$/.test(String(sha))) return null;
+  let buf;
+  try {
+    buf = fs.readFileSync(copyFile(sha));
+  } catch (_) {
+    sendUi("notice", { message: "That copy is not on this computer." });
+    return { ok: false, missing: true };
+  }
+  if (sha256Of(buf) !== sha) {
+    sendUi("notice", { message: "This copy has changed since it was saved, so it was not opened." });
+    return { ok: false, changed: true };
+  }
+  createTab(require("url").pathToFileURL(copyFile(sha)).href);
+  return { ok: true };
 }
 function engageUrl(url, reason) {
   const tab = [...tabs.values()].find((t) => t.page?.url === url);
@@ -666,7 +821,10 @@ function placeCard(id, url, opts = {}) {
 
 function trailSnapshot(id) {
   research.saveNow();
-  return trailStore.snapshot(id || research.current.id);
+  const snap = trailStore.snapshot(id || research.current.id);
+  // B87: whether each saved copy is on this computer.
+  if (snap) snap.cards = snap.cards.map((c) => (c.copies?.length ? { ...c, copies: c.copies.map((x) => ({ ...x, here: fs.existsSync(copyFile(x.sha256)) })) } : c));
+  return snap;
 }
 
 // ---- Trails keep their own tabs (B80, docs/18-sidebar-chrome.md) ----
@@ -1939,6 +2097,7 @@ function contextMenuItems(tab, p, { video = p.mediaType === "video" } = {}) {
       { label: "Reload", click: () => wc.reload() },
       { type: "separator" },
       { label: "Save Page as PDF", click: () => savePdf(tab.id) },
+      ...(tab.private ? [] : [{ label: "Save a Copy of This Page", click: () => copyTab(tab) }]), // B87
       { label: "Print…", click: () => wc.print({}, () => {}) },
       { label: "Screenshot Tab", click: () => runShotFromMain(tab.id) }
     );
@@ -2480,6 +2639,7 @@ function buildMenu() {
         { label: "Bookmarks", accelerator: "CmdOrCtrl+Shift+B", click: () => sendUi("open-bookmarks") },
         { type: "separator" },
         { label: "Share Trail…", click: () => sendUi("share-trail") },
+        { label: "Save a Copy of This Page", click: () => copyTab(tabs.get(activeId)) },
         { label: "Open Trail File…", accelerator: "CmdOrCtrl+O", click: () => chooseSharedTrail() },
         { type: "separator" },
         { label: "Screenshot Tab", accelerator: "CmdOrCtrl+Shift+S", click: () => runShotFromMain(activeId) },
@@ -4152,6 +4312,7 @@ function shareFileInfo() {
     timeline: items.length,
     timelineOnly: items.filter((i) => i.timelineOnly).length,
     tabs: openTabCards(snap).length,
+    copies: shareCopies(snap).length,
   };
 }
 function shareFileText(opts = {}) {
@@ -4162,8 +4323,14 @@ function shareFileText(opts = {}) {
     startHere: opts.startHere || "",
     timeline: opts.timeline !== false,
     openTabs: opts.tabs ? openTabCards(snap) : [],
+    copies: opts.copiesFolder ? { folder: opts.copiesFolder, include: shareCopies(snap) } : null,
   });
 }
+// B87: the saved copies a shared file can carry (on this computer, in cards
+// that go in the file).
+function shareCopies(snap = shareSnapshot()) {
+  return [...new Set(snap.cards.filter((c) => c.kind === "page" && !c.removed && !(c.url && isSensitiveUrl(c.url))).flatMap((c) => (c.copies || []).map((x) => x.sha256)))].filter((sha) => fs.existsSync(copyFile(sha)));
+}
 ipcMain.handle("trail:share-text", (_e, opts) => shareFileText(opts || {}));
 // Builds the file text. opts: { pages: [urls], reports: bool, tabs: bool }.
 function trailFileText(opts = {}) {
@@ -4179,7 +4346,6 @@ function trailFileText(opts = {}) {
 const trailFileName = (name) => `${String(name || "Trail").replace(/[\\/:*?"<>|\u0000-\u001f]+/g, " ").replace(/\s+/g, " ").trim().slice(0, 80) || "Trail"}.trail.md`;
 let trailSavePath = null; // tests set a path instead of the Save dialog
 ipcMain.handle("trail:share-save", async (_e, opts = {}) => {
-  const text = shareFileText(opts);
   let file = trailSavePath;
   if (!file) {
     const r = await dialog.showSaveDialog(win, {
@@ -4191,14 +4357,26 @@ ipcMain.handle("trail:share-save", async (_e, opts = {}) => {
     if (r.canceled || !r.filePath) return { ok: false, canceled: true };
     file = r.filePath.endsWith(".md") ? r.filePath : `${r.filePath}.trail.md`;
   }
+  // B87: saved copies go in a folder beside the file, "<name> copies".
+  const folder = opts.copies ? `${path.basename(file).replace(/(\.trail)?\.md$/i, "")} copies` : "";
+  const text = shareFileText({ ...opts, copiesFolder: folder });
+  let copied = 0;
   try {
     fs.writeFileSync(file, text);
+    if (folder) {
+      const dir = path.join(path.dirname(file), folder);
+      fs.mkdirSync(dir, { recursive: true });
+      for (const sha of shareCopies()) {
+        fs.copyFileSync(copyFile(sha), path.join(dir, `${sha}.mhtml`));
+        copied++;
+      }
+    }
   } catch (err) {
     return { ok: false, error: `The file could not be saved: ${err.message}` };
   }
   usage().count("trailsShared");
   const back = TrailFile.parseTrailMd(text);
-  return { ok: true, file, name: path.basename(file), cards: back.cards.length, links: back.lines.length };
+  return { ok: true, file, name: path.basename(file), cards: back.cards.length, links: back.lines.length, copies: copied, folder };
 });
 // ---- Opening a shared trail (B82 step 5) ----
 // The file is read and checked; the Trail section shows a preview, then Open
@@ -4237,6 +4415,7 @@ function openTrailFileV2(file, text) {
     sendUi("shared-trail", { payload: { error: `${path.basename(file)}: ${err.message}` } });
     return { ok: false, error: err.message };
   }
+  takeCopies(file, data);
   research.saveNow();
   let opened;
   changeTrail(() => {
@@ -4247,6 +4426,29 @@ function openTrailFileV2(file, text) {
   sendUi("trail-opened", { payload: trailSnapshot(opened.trail.id) });
   return { ok: true, id: opened.trail.id };
 }
+// B87: copies sent beside a trail file come into this computer's copies
+// when their SHA-256 matches the file; one that doesn't is marked changed.
+function takeCopies(file, data) {
+  const dir = path.dirname(file);
+  for (const c of data.cards || []) {
+    for (const x of c.copies || []) {
+      if (!x.file) continue;
+      const p = path.resolve(dir, x.file);
+      delete x.file;
+      if (!p.startsWith(dir + path.sep) || !/\.mhtml$/i.test(p)) continue;
+      try {
+        const buf = fs.readFileSync(p);
+        if (buf.length > 100 * 1024 * 1024) continue;
+        if (sha256Of(buf) !== x.sha256) {
+          x.changed = true;
+          continue;
+        }
+        fs.mkdirSync(copiesDir(), { recursive: true });
+        if (!fs.existsSync(copyFile(x.sha256))) fs.writeFileSync(copyFile(x.sha256), buf);
+      } catch (_) {}
+    }
+  }
+}
 function openSharedTrail(file) {
   let text = "";
   try {
diff --git a/package.json b/package.json
index 1bb78ae..acfa13b 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,7 @@
     "test:provenance": "node test/provenance-demo.js",
     "test:recall": "node test/recall-demo.js",
     "test:moment": "node test/moment-demo.js",
+    "test:copies": "node test/copies-demo.js",
     "test:trailfile": "node test/trail-file-v2-demo.js",
     "try:canvas": "node test/try-canvas.js",
     "test:keywords": "node test/keywords-demo.js",
@@ -38,7 +39,7 @@
     "dist:mac": "electron-builder --mac",
     "dist:win": "electron-builder --win",
     "test:redteam": "node test/e2e/18-redteam.js",
-    "test:unit": "node test/net-demo.js && node test/trail-demo.js && node test/canvas-demo.js && node test/placement-demo.js && node test/ladder-demo.js && node test/replay-demo.js && node test/provenance-demo.js && node test/recall-demo.js && node test/moment-demo.js && node test/share-link-demo.js && node test/share-worker-demo.js && node test/trail-file-demo.js && node test/trail-file-v2-demo.js && node test/threads-demo.js && node test/trail-open-demo.js && node test/passwords-demo.js && node test/chat-demo.js && node test/usage-demo.js && node test/research-demo.js && node test/keywords-demo.js && node test/keywords-eval.js && node test/providers-demo.js && node test/rules-demo.js && node test/ai-demo.js && node test/controller-demo.js && node test/playback-demo.js && node test/bookmarks-demo.js && node test/google-demo.js && node test/agents-demo.js && node test/agent-demo.js && node test/talk-demo.js",
+    "test:unit": "node test/net-demo.js && node test/trail-demo.js && node test/canvas-demo.js && node test/placement-demo.js && node test/ladder-demo.js && node test/replay-demo.js && node test/provenance-demo.js && node test/recall-demo.js && node test/moment-demo.js && node test/copies-demo.js && node test/share-link-demo.js && node test/share-worker-demo.js && node test/trail-file-demo.js && node test/trail-file-v2-demo.js && node test/threads-demo.js && node test/trail-open-demo.js && node test/passwords-demo.js && node test/chat-demo.js && node test/usage-demo.js && node test/research-demo.js && node test/keywords-demo.js && node test/keywords-eval.js && node test/providers-demo.js && node test/rules-demo.js && node test/ai-demo.js && node test/controller-demo.js && node test/playback-demo.js && node test/bookmarks-demo.js && node test/google-demo.js && node test/agents-demo.js && node test/agent-demo.js && node test/talk-demo.js",
     "release": "electron-builder --publish always",
     "build:browser-extension": "node browser/extension/build.js",
     "check:browser-patches": "python3 browser/check_patches.py",
diff --git a/preload.js b/preload.js
index 240da00..24e31f9 100644
--- a/preload.js
+++ b/preload.js
@@ -120,6 +120,10 @@ contextBridge.exposeInMainWorld("scout", {
   trailMomentPlay: (id) => ipcRenderer.invoke("trail:moment-play", id),
   trailMomentTimes: (id, a, b) => ipcRenderer.invoke("trail:moment-times", id, a, b),
   trailMomentId: (id) => ipcRenderer.invoke("trail:moment-id", id),
+  // B87: saved copies.
+  trailCopySave: (cardId) => ipcRenderer.invoke("trail:copy-save", cardId),
+  trailCopyOpen: (sha) => ipcRenderer.invoke("trail:copy-open", sha),
+  trailKeepCopies: (id, on) => ipcRenderer.invoke("trail:keep-copies", id, on),
   historyClear: () => ipcRenderer.invoke("history:clear"),
   claudeDesktop: (mode) => ipcRenderer.invoke("agents:claude-desktop", mode),
   historyRemove: (url) => ipcRenderer.invoke("history:remove", url),
diff --git a/renderer/app.js b/renderer/app.js
index fd941dc..f74be33 100644
--- a/renderer/app.js
+++ b/renderer/app.js
@@ -2793,6 +2793,10 @@ async function openShareSheet() {
   document.getElementById("share-tabs-label").textContent = `Open tabs: which cards are open in a tab (${f.tabs})`;
   document.getElementById("share-tabs").checked = false;
   document.getElementById("share-tabs").disabled = !f.tabs;
+  // B87: copies go only when ticked, as files in a folder beside the trail file.
+  document.getElementById("share-copies-label").textContent = `Saved copies of pages, in a folder beside the file (${f.copies || 0})`;
+  document.getElementById("share-copies").checked = false;
+  document.getElementById("share-copies").disabled = !f.copies;
   paintSharePreview();
   document.getElementById("link-made").hidden = true;
   // Share links (B82, unchanged): only when the share server answers.
@@ -2823,6 +2827,7 @@ const fileChoices = () => ({
   startHere: document.getElementById("share-start").value,
   timeline: document.getElementById("share-timeline").checked,
   tabs: document.getElementById("share-tabs").checked,
+  copies: document.getElementById("share-copies").checked,
 });
 let previewSeq = 0;
 async function paintSharePreview() {
@@ -2901,7 +2906,9 @@ document.getElementById("share-save").addEventListener("click", async () => {
   const r = await api.trailShareSave(fileChoices());
   if (r.canceled) return;
   if (!r.ok) return (msg.textContent = r.error);
-  msg.textContent = `Saved: ${r.name} · ${plural(r.cards, "card", "cards")}, ${plural(r.links, "link", "links")}. Send it with any app: Messages, email, Telegram, Discord or AirDrop. `;
+  msg.textContent = r.copies
+    ? `Saved: ${r.name} · ${plural(r.cards, "card", "cards")}, ${plural(r.links, "link", "links")}, and ${plural(r.copies, "saved copy", "saved copies")} in the folder “${r.folder}”. Send the file and the folder together. `
+    : `Saved: ${r.name} · ${plural(r.cards, "card", "cards")}, ${plural(r.links, "link", "links")}. Send it with any app: Messages, email, Telegram, Discord or AirDrop. `;
   const show = el("button", "link-btn", "Show in Folder");
   show.addEventListener("click", () => api.trailShowFile(r.file));
   msg.appendChild(show);
@@ -3902,6 +3909,9 @@ async function openCanvas({ focus = false, select = "" } = {}) {
     webSearch: (q) => api.trailSearch(q),
     privateSearch: (q) => api.trailSearch(q, { private: true }),
     ask: (q) => askAboutTrail(q),
+    // B87: saved copies.
+    copySave: (id) => api.trailCopySave(id),
+    copyOpen: (sha) => api.trailCopyOpen(sha),
     // B88: moment cards.
     momentPlay: (id) => api.trailMomentPlay(id),
     momentTimes: (id, a, b) => api.trailMomentTimes(id, a, b),
@@ -4754,6 +4764,16 @@ function trailActions(row, t, more) {
     acts.remove();
     renameRow(row, t);
   }, t.readonly, t.readonly ? "Read only. Save as new trail to change it." : "");
+  // B87: keep a copy of each page that becomes a card in this trail.
+  if (!t.readonly) {
+    const keep = btn(`Keep copies: ${t.keepCopies ? "On" : "Off"}`, "", async () => {
+      t.keepCopies = Boolean(await api.trailKeepCopies(t.id, !t.keepCopies));
+      keep.textContent = `Keep copies: ${t.keepCopies ? "On" : "Off"}`;
+      keep.setAttribute("aria-pressed", String(t.keepCopies));
+    });
+    keep.setAttribute("aria-pressed", String(Boolean(t.keepCopies)));
+    keep.title = "Save a copy of each page that becomes a card. Copies stay on this computer.";
+  }
   const del = btn("Delete…", "", () => confirmDelete(acts, t));
   row.after(acts);
   (t.readonly ? del : first).focus();
diff --git a/renderer/canvas.js b/renderer/canvas.js
index c13ddb2..0c29965 100644
--- a/renderer/canvas.js
+++ b/renderer/canvas.js
@@ -117,6 +117,11 @@
     const hh = Math.floor(t / 3600), m = Math.floor((t % 3600) / 60), s = String(t % 60).padStart(2, "0");
     return hh ? `${hh}:${String(m).padStart(2, "0")}:${s}` : `${m}:${s}`;
   };
+  // "7 Nov 21:40", for saved copies (B87).
+  const copyText = (t) => {
+    const d = new Date(t);
+    return `${d.getDate()} ${["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"][d.getMonth()]} ${String(d.getHours()).padStart(2, "0")}:${String(d.getMinutes()).padStart(2, "0")}`;
+  };
   const secsText = (s) => String(s).split(":").reduce((n, p) => n * 60 + Number(p), 0);
   const KIND_LABEL = { page: "Page", video: "Video", capture: "Capture", report: "Report", question: "Question", note: "Note", voice: "Voice", search: "Search", media: "Media", moment: "Moment" };
   const MEDIA_LABEL = { image: "Image", screenshot: "Screenshot", video: "Video", audio: "Audio" };
@@ -322,7 +327,22 @@
       rm.type = "button";
       rm.addEventListener("click", () => this.selected && this.hooks.remove?.(this.selected));
       this.selRemove = rm;
-      this.selBar.append(this.selMeta, openB, rm);
+      // B87: a copy of the page as it looks now, kept on this computer.
+      const cp = h("button", "cv-selbar-btn", "Save a copy");
+      cp.type = "button";
+      cp.addEventListener("click", async () => {
+        if (!this.selected) return;
+        cp.disabled = true;
+        cp.textContent = "Saving…";
+        try {
+          await this.hooks.copySave?.(this.selected);
+        } finally {
+          cp.disabled = false;
+          cp.textContent = "Save a copy";
+        }
+      });
+      this.selCopy = cp;
+      this.selBar.append(this.selMeta, openB, cp, rm);
       // Opened trail files are read only (B109): trying to change one says so.
       this.roMsg = h("div", "cv-readonly-msg", "Read only. Save as new trail to change it.");
       this.roMsg.setAttribute("role", "status");
@@ -890,6 +910,23 @@
         if (root.NodeProvenance.CHOSEN_BY_NODE.has(c.via?.how) || (!c.via && c.played)) line.classList.add("node");
         el.append(line);
       }
+      // B87: the newest saved copy. Opens it; says when it changed or stayed
+      // with the sender.
+      const copy = c.kind === "page" && c.copies?.length ? c.copies[c.copies.length - 1] : null;
+      if (copy) {
+        const when = copy.atText || copyText(copy.at);
+        const changed = c.copies.filter((x) => x.changed).length;
+        const b = h("button", "cv-card-copy cv-media-ctl", copy.changed ? `Copy changed since ${when}` : copy.here === false ? `Copy ${when} · kept by the sender` : `Copy · ${when}${c.copies.length > 1 ? ` · ${c.copies.length} copies` : ""}${changed ? ` · ${changed} changed` : ""}`);
+        b.type = "button";
+        b.title = `SHA-256 ${copy.sha256}${changed ? `\n${changed === 1 ? "One copy has" : `${changed} copies have`} changed since it was saved, so ${changed === 1 ? "it isn't" : "they aren't"} trusted.` : ""}`;
+        if (changed) b.classList.add("changed");
+        b.disabled = Boolean(copy.changed) || copy.here === false;
+        b.addEventListener("click", (e) => {
+          e.stopPropagation();
+          this.hooks.copyOpen?.(copy.sha256);
+        });
+        el.append(b);
+      }
       const foot = this.cardFoot(c);
       if (foot) el.append(h("div", "cv-card-foot", foot));
       el.setAttribute("aria-label", `${KIND_LABEL[c.kind] || "Card"}: ${title || ""}${pv ? ", open in a tab" : ""}`);
@@ -1505,6 +1542,7 @@
       if (!c) return;
       this.selMeta.textContent = c.url ? hostOf(c.url) : KIND_LABEL[c.kind] || "";
       this.selOpen.hidden = !c.url;
+      this.selCopy.hidden = this.readonly || c.kind !== "page" || !this.hooks.copySave;
       const vp = this.vp.getBoundingClientRect(), el = this.el.getBoundingClientRect();
       const x = vp.left - el.left + this.v.x + c.x * this.v.z;
       const y = vp.top - el.top + this.v.y + c.y * this.v.z - 8;
diff --git a/renderer/index.html b/renderer/index.html
index b60e7f8..270e811 100644
--- a/renderer/index.html
+++ b/renderer/index.html
@@ -361,6 +361,7 @@ <h1>Trail</h1>
             <p class="help" id="share-always"></p>
             <label class="toggle"><input type="checkbox" id="share-timeline" checked /> <span id="share-timeline-label">Timeline</span></label>
             <label class="toggle"><input type="checkbox" id="share-tabs" /> <span id="share-tabs-label">Open tabs</span></label>
+            <label class="toggle"><input type="checkbox" id="share-copies" /> <span id="share-copies-label">Saved copies</span></label>
             <p class="help">Never in the file: screenshots (they stay on this computer), sign-in, account and payment pages, private parts of addresses and tracking codes, private tabs and other trails.</p>
             <details class="share-preview"><summary>Preview the file</summary><pre id="share-preview-text"></pre></details>
             <div class="actions-row">
diff --git a/renderer/styles.css b/renderer/styles.css
index 3e6ed8e..1e37d94 100644
--- a/renderer/styles.css
+++ b/renderer/styles.css
@@ -1361,6 +1361,11 @@ body.side #canvas { grid-column: 2; grid-row: 1; border: 1px solid var(--line);
 #canvas .cv-card.k-note .cv-card-title { font-weight: 400; -webkit-line-clamp: 5; }
 #canvas .cv-card.k-capture .cv-card-title { font-weight: 400; font-style: italic; }
 #canvas .cv-card-sub { font-size: 13px; line-height: 18px; color: var(--ink-muted); overflow: hidden; display: -webkit-box; -webkit-line-clamp: 4; -webkit-box-orient: vertical; }
+/* Saved copies (B87): the newest copy, under the title. */
+#canvas .cv-card-copy { align-self: flex-start; max-width: 100%; margin-top: 2px; padding: 0; border: 0; background: transparent; color: var(--ink-muted); font: 11px/14px var(--mono); text-align: left; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; cursor: pointer; flex: none; }
+#canvas .cv-card-copy:hover:not(:disabled) { color: var(--ink); text-decoration: underline; }
+#canvas .cv-card-copy:disabled { cursor: default; }
+#canvas .cv-card-copy.changed { color: var(--alert); }
 /* Media moments (B88): times, captions, Play and Ask for ID. */
 #canvas .cv-moment-times { align-self: flex-start; margin: 2px 0 0; padding: 2px 6px; border: 1px solid var(--line); border-radius: var(--radius-sm); background: transparent; color: var(--ink); font: 14px/18px var(--mono); cursor: text; }
 #canvas .cv-moment-times:disabled { cursor: default; border-color: transparent; padding-left: 0; }
diff --git a/test/copies-demo.js b/test/copies-demo.js
new file mode 100644
index 0000000..c9f56a6
--- /dev/null
+++ b/test/copies-demo.js
@@ -0,0 +1,70 @@
+// Saved copies (B87): copies on page cards, the trail setting, and the
+// trail file. The files themselves are main.js's (see e2e 53).
+// Run: npm run test:copies
+const assert = require("assert");
+const { TrailStore } = require("../core/trail");
+const { memoryStorage } = require("../core/storage");
+const TF = require("../core/trail-file");
+
+let n = 0;
+const ok = (name) => console.log(`ok ${++n} - ${name}`);
+let clock = new Date(2026, 10, 8, 10, 5).getTime();
+const now = () => clock;
+const store = new TrailStore(memoryStorage(), { now });
+const id = store.current().trail.id;
+const A = "https://example.com/levain", B = "https://example.com/rye";
+const H1 = "a".repeat(64), H2 = "b".repeat(64);
+store.visit(id, A, { title: "Levain" });
+clock += 20000;
+const card = store.placePage(id, A, { title: "Levain", x: 0, y: 0 });
+{
+  const c1 = store.addCopy(id, A, { sha256: H1, bytes: 120000 });
+  assert.deepStrictEqual(c1, { at: clock, sha256: H1, bytes: 120000 });
+  assert.strictEqual(store.addCopy(id, A, { sha256: H1, bytes: 120000 }), c1, "the same page again is the same copy");
+  clock += 3600000;
+  store.addCopy(id, A, { sha256: H2, bytes: 130000 });
+  assert.strictEqual(store.card(id, card.id).copies.length, 2, "a changed page is a second copy");
+  assert.strictEqual(store.events(id).filter((e) => e.type === "copied").length, 2, "each copy is an event");
+  assert.strictEqual(store.addCopy(id, B, { sha256: H1 }), null, "only pages with a card");
+  assert.strictEqual(store.addCopy(id, A, { sha256: "nothex" }), null);
+  store.visit(id, "https://accounts.google.com/signin", { title: "Sign in" });
+  assert.strictEqual(store.addCopy(id, "https://accounts.google.com/signin", { sha256: H1 }), null, "never sign-in pages (B66)");
+  assert.deepStrictEqual([...store.copyHashes()].sort(), [H1, H2]);
+  assert.ok(!store.timeline(id).flatMap((s) => s.items).some((i) => i.type === "copied"), "copies don't add timeline rows");
+  ok("a page card keeps its copies, newest last, each once, each an event");
+}
+{
+  assert.strictEqual(store.list()[0].keepCopies, false);
+  assert.strictEqual(store.setKeepCopies(id, true), true);
+  assert.strictEqual(new TrailStore(store.storage, { now }).list()[0].keepCopies, true, "the setting is saved with the trail");
+  ok("the trail setting “Keep copies” is per trail and saved");
+}
+{
+  const snap = store.snapshot(id);
+  const md = TF.toTrailMd(snap, { by: "Sven", at: clock });
+  assert.ok(md.includes(`Copy: 8 Nov 2026 10:05 · SHA-256 ${H1}\n`), md);
+  assert.ok(md.includes(`Copy: 8 Nov 2026 11:05 · SHA-256 ${H2}\n`));
+  assert.ok(!md.includes("[saved copy]"), "without the choice, copies are only listed");
+  const back = TF.parseTrailMd(md);
+  const c = back.cards.find((k) => k.url === A);
+  assert.deepStrictEqual(c.copies, [{ atText: "8 Nov 2026 10:05", sha256: H1 }, { atText: "8 Nov 2026 11:05", sha256: H2 }]);
+  assert.ok(!/Copy:/.test(c.excerpt || ""), "copy lines are not read as the excerpt");
+  assert.strictEqual(TF.toTrailMd(back, { by: "Sven", at: back.trail.at }), md, "the file reads back the same");
+  const md2 = TF.toTrailMd(snap, { by: "Sven", at: clock, copies: { folder: "Levain trail copies", include: [H2] } });
+  assert.ok(md2.includes(`Copy: 8 Nov 2026 11:05 · SHA-256 ${H2} · [saved copy](Levain%20trail%20copies/${H2}.mhtml)`), md2);
+  assert.ok(md2.includes(`Copy: 8 Nov 2026 10:05 · SHA-256 ${H1}\n`), "copies not sent stay listed only");
+  const back2 = TF.parseTrailMd(md2);
+  assert.strictEqual(back2.cards.find((k) => k.url === A).copies[1].file, `Levain trail copies/${H2}.mhtml`);
+  const reader = new TrailStore(memoryStorage(), { now });
+  const opened = reader.importFile(back2);
+  assert.strictEqual(reader.snapshot(opened.trail.id).cards.find((k) => k.url === A).copies.length, 2, "the reader's trail lists them");
+  ok("trail files list copies with time and SHA-256; sent copies link to the folder beside the file");
+}
+{
+  const ro = new TrailStore(memoryStorage(), { now });
+  const f = ro.importFile(TF.parseTrailMd(TF.toTrailMd(store.snapshot(id), { by: "Sven", at: clock }))).trail.id;
+  assert.strictEqual(ro.addCopy(f, A, { sha256: "c".repeat(64) }), null);
+  assert.strictEqual(ro.setKeepCopies(f, true), null);
+  ok("an opened file (read only) gets no new copies or setting");
+}
+console.log(`\n${n} checks passed`);
diff --git a/test/e2e/53-saved-copies.js b/test/e2e/53-saved-copies.js
new file mode 100644
index 0000000..e3a9cb1
--- /dev/null
+++ b/test/e2e/53-saved-copies.js
@@ -0,0 +1,161 @@
+// Saved copies (B87): "Save a Copy of This Page" (File menu, right-click) and
+// "Save a copy" on a page card save the page as an MHTML file named by its
+// SHA-256, with its text, on this computer. The card says so and opens the
+// copy after checking its hash. "Keep copies" in a trail's … menu saves one
+// for each page that becomes a card. Sharing sends copies only when ticked,
+// in a folder beside the file; opening the file checks each one.
+const { _electron: electron } = require(process.env.PLAYWRIGHT_PATH || "playwright");
+const path = require("path"), fs = require("fs"), os = require("os"), crypto = require("crypto");
+const OUT = process.argv[2] || fs.mkdtempSync(path.join(os.tmpdir(), "node-e2e-"));
+const BASE = "http://127.0.0.1:8765";
+const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
+let failed = 0;
+const check = (name, ok, detail = "") => {
+  if (!ok) failed++;
+  console.log(ok ? "✓" : "✗", name, detail ? `(${detail})` : "");
+};
+const userData = fs.mkdtempSync(path.join(OUT, "ud-"));
+fs.writeFileSync(path.join(userData, "settings.json"), JSON.stringify({ firstRunDone: true }));
+const copies = path.join(userData, "copies");
+const sha = (f) => crypto.createHash("sha256").update(fs.readFileSync(f)).digest("hex");
+
+(async () => {
+  const app = await electron.launch({ executablePath: require("electron"), args: ["--no-sandbox", `--user-data-dir=${userData}`, path.join(__dirname, "..", "..")] });
+  await app.evaluate(() => {
+    const o = globalThis.fetch;
+    globalThis.fetch = async (u, opt) => (/wikipedia|duckduckgo|brave\.com|x\.ai|11434/.test(String(u)) ? new Response("{}", { status: 200 }) : o(u, opt));
+  });
+  const ui = await app.firstWindow();
+  await sleep(1800);
+  const menuItem = (label) => app.evaluate(({ Menu }, l) => Menu.getApplicationMenu().items.flatMap((m) => m.submenu?.items || []).find((i) => i.label === l).click(), label);
+  const cards = async () => (await ui.evaluate(() => window.scout.trailGet())).cards;
+  const cardOf = async (re) => (await cards()).find((c) => c.kind === "page" && re.test(c.url));
+  const tabUrls = () => app.evaluate(({ webContents }) => webContents.getAllWebContents().map((w) => w.getURL()));
+  await ui.evaluate(() => window.scout.trailRename("Bread notes"));
+
+  // File → Save a Copy of This Page.
+  await ui.evaluate((u) => window.scout.createTab(u), `${BASE}/article.html`);
+  await sleep(1800);
+  await menuItem("Save a Copy of This Page");
+  await sleep(2500);
+  let art = await cardOf(/article\.html/);
+  const c1 = art?.copies?.[0];
+  check("the page became a card with a saved copy", c1 && /^[0-9a-f]{64}$/.test(c1.sha256) && c1.bytes > 1000 && c1.here === true, JSON.stringify(c1));
+  const file1 = c1 && path.join(copies, `${c1.sha256}.mhtml`);
+  check("the copy is an MHTML file named by its SHA-256", file1 && fs.existsSync(file1) && sha(file1) === c1.sha256 && /^From: <Saved by Blink>|MIME-Version/m.test(fs.readFileSync(file1, "utf8").slice(0, 2000)));
+  check("with the page's text beside it, for search", c1 && /starter/i.test(fs.readFileSync(path.join(copies, `${c1.sha256}.txt`), "utf8")));
+  await menuItem("Save a Copy of This Page");
+  await sleep(2000);
+  art = await cardOf(/article\.html/);
+  check("saving again an unchanged page keeps one copy", art.copies.length === 1, String(art.copies.length));
+
+  // A sign-in page is never saved (B66).
+  await ui.evaluate((u) => window.scout.createTab(u), `${BASE}/login.html`);
+  await sleep(1500);
+  await menuItem("Save a Copy of This Page");
+  await sleep(1500);
+  check("a sign-in page is never saved", !(await cards()).some((c) => /login\.html/.test(c.url || "")) && fs.readdirSync(copies).filter((f) => f.endsWith(".mhtml")).length === 1);
+
+  // The card: Copy · <time>, which opens the copy.
+  await menuItem("Tab 1");
+  await sleep(1500);
+  await ui.evaluate((id) => trailCanvas.select(id, { reveal: true }), art.id);
+  await sleep(500);
+  const line = await ui.evaluate((id) => {
+    const b = document.querySelector(`#canvas .cv-card[data-id="${id}"] .cv-card-copy`);
+    return b && { text: b.textContent, title: b.title };
+  }, art.id);
+  check("the card says a copy was saved, with its SHA-256", line && /^Copy · \d{1,2} [A-Z][a-z]{2} \d\d:\d\d$/.test(line.text) && line.title === `SHA-256 ${c1.sha256}`, JSON.stringify(line));
+  await ui.screenshot({ path: path.join(OUT, "53-card.png") });
+  await ui.click(`#canvas .cv-card[data-id="${art.id}"] .cv-card-copy`);
+  await sleep(1800);
+  check("clicking it opens the copy in a tab", (await tabUrls()).some((u) => u.startsWith("file://") && u.endsWith(`${c1.sha256}.mhtml`)));
+  // A copy that changed on disk is not opened.
+  const good = fs.readFileSync(file1);
+  fs.writeFileSync(file1, Buffer.concat([good, Buffer.from("\nchanged")]));
+  const before = (await tabUrls()).length;
+  const r = await ui.evaluate((h) => window.scout.trailCopyOpen(h), c1.sha256);
+  check("a copy that changed since it was saved is not opened", r.changed === true && (await tabUrls()).length === before, JSON.stringify(r));
+  fs.writeFileSync(file1, good);
+
+  // "Save a copy" on a card with no tab: loads it out of sight.
+  await ui.evaluate((u) => window.scout.createTab(u), `${BASE}/seealso.html`);
+  await sleep(1500);
+  await menuItem("Save a Copy of This Page"); // makes it a card (and a copy)
+  await sleep(2000);
+  const see = await cardOf(/seealso/);
+  const tabId = await ui.evaluate(() => activeId);
+  await ui.evaluate((id) => window.scout.closeTab(id), tabId);
+  await sleep(800);
+  await menuItem("Tab 1");
+  await sleep(1200);
+  await ui.evaluate((id) => trailCanvas.select(id, { reveal: true }), see.id);
+  await sleep(400);
+  const bar = await ui.evaluate(() => [...document.querySelectorAll("#canvas .cv-selbar button")].filter((b) => !b.hidden).map((b) => b.textContent));
+  check("a selected page card offers Save a copy", bar.includes("Save a copy"), bar.join());
+  // Make the page different so the copy is new.
+  await ui.evaluate(() => [...document.querySelectorAll("#canvas .cv-selbar button")].find((b) => b.textContent === "Save a copy").click());
+  await sleep(5000);
+  const see2 = await cardOf(/seealso/);
+  check("it saves a copy without opening a tab", see2.copies.length >= 1 && !(await tabUrls()).some((u) => /seealso/.test(u)), JSON.stringify(see2.copies));
+
+  // Keep copies: each page that becomes a card gets one.
+  await ui.click("#sb-switch-name");
+  await sleep(300);
+  await ui.evaluate(() => [...document.querySelectorAll("#sb-switch-menu .sb-menu-row")].find((r) => r.querySelector(".nm").textContent === "Bread notes").querySelector(".sb-menu-more").click());
+  await sleep(300);
+  const keep = await ui.evaluate(() => [...document.querySelectorAll("#sb-switch-menu .chip")].find((b) => /^Keep copies/.test(b.textContent)));
+  check("the trail's … menu has Keep copies: Off", Boolean(keep) && (await ui.evaluate(() => [...document.querySelectorAll("#sb-switch-menu .chip")].find((b) => /^Keep copies/.test(b.textContent)).textContent)) === "Keep copies: Off");
+  await ui.evaluate(() => [...document.querySelectorAll("#sb-switch-menu .chip")].find((b) => /^Keep copies/.test(b.textContent)).click());
+  await sleep(500);
+  check("clicking turns it on", (await ui.evaluate(() => window.scout.trailList().then((l) => l.find((t) => t.current).keepCopies))) === true);
+  await ui.evaluate(() => closeSwitchMenu());
+  await ui.evaluate((u) => window.scout.createTab(u), `${BASE}/other.html?n=kept`);
+  await sleep(1500);
+  const trailId = (await ui.evaluate(() => window.scout.trailGet())).trail.id;
+  await ui.evaluate(() => window.scout.researchNew("Elsewhere")); // the open page becomes a card
+  await sleep(4000);
+  await ui.evaluate((id) => window.scout.trailSwitch(id), trailId);
+  await sleep(1500);
+  const kept = await cardOf(/n=kept/);
+  check("with Keep copies on, a page that becomes a card gets a copy", kept?.copies?.length === 1, JSON.stringify(kept?.copies));
+
+  // Share: copies only when ticked, in a folder beside the file.
+  const shareDir = fs.mkdtempSync(path.join(OUT, "share-"));
+  const plain = path.join(shareDir, "Plain.trail.md");
+  await app.evaluate((_e, f) => global.nodeTest.setTrailSavePath(f), plain);
+  const r1 = await ui.evaluate(() => window.scout.trailShareSave({}));
+  check("without the choice: copies are listed, not sent", r1.ok && !r1.copies && /Copy: .* · SHA-256 [0-9a-f]{64}\n/.test(fs.readFileSync(plain, "utf8")) && !fs.existsSync(path.join(shareDir, "Plain copies")));
+  const withCopies = path.join(shareDir, "Bread notes.trail.md");
+  await app.evaluate((_e, f) => global.nodeTest.setTrailSavePath(f), withCopies);
+  const r2 = await ui.evaluate(() => window.scout.trailShareSave({ copies: true }));
+  const dir = path.join(shareDir, "Bread notes copies");
+  const sent = fs.existsSync(dir) ? fs.readdirSync(dir) : [];
+  check("ticked: the copies go in “<name> copies” beside the file", r2.ok && r2.copies === sent.length && sent.length >= 3 && sent.every((f) => sha(path.join(dir, f)) === f.replace(".mhtml", "")), JSON.stringify({ r2, sent }));
+  check("and the file links to them", fs.readFileSync(withCopies, "utf8").includes(`[saved copy](Bread%20notes%20copies/${c1.sha256}.mhtml)`));
+
+  // Opening it: matching copies come in; a changed one is marked.
+  fs.rmSync(file1);
+  const other = sent.find((f) => f !== `${c1.sha256}.mhtml`);
+  fs.appendFileSync(path.join(dir, other), "\nedited by someone");
+  await app.evaluate((_e, f) => global.nodeTest.openSharedTrail(f), withCopies);
+  await sleep(2500);
+  const opened = await ui.evaluate(() => window.scout.trailGet());
+  check("the file opens read only", opened.trail.readonly === true);
+  const oc = opened.cards.find((c) => /article\.html/.test(c.url || ""));
+  check("a copy that matches its SHA-256 comes onto this computer", fs.existsSync(file1) && oc.copies[0].here === true && !oc.copies[0].changed);
+  const changed = opened.cards.flatMap((c) => c.copies || []).filter((x) => x.changed);
+  check("a copy that doesn't match is marked changed", changed.length === 1 && `${changed[0].sha256}.mhtml` === other, JSON.stringify(changed));
+  await menuItem("Tab 1").catch(() => {});
+  await sleep(1200);
+  const texts = await ui.evaluate(() => [...document.querySelectorAll("#canvas .cv-card-copy")].map((b) => b.textContent));
+  check("its card says so", texts.some((t) => /changed/.test(t)), JSON.stringify(texts));
+  await ui.screenshot({ path: path.join(OUT, "53-opened.png") });
+
+  await app.close();
+  console.log(failed ? `\n${failed} FAILED` : "\nall passed");
+  process.exit(failed ? 1 : 0);
+})().catch((e) => {
+  console.error(e);
+  process.exit(1);
+});
diff --git a/test/e2e/README.md b/test/e2e/README.md
index 8a0df22..27dbcb5 100644
--- a/test/e2e/README.md
+++ b/test/e2e/README.md
@@ -33,6 +33,7 @@ On Linux without a display, run each script under `xvfb-run -a`.
 | 50-provenance | Trail provenance (B83): a typed address, a link clicked on a page, a suggestion with its keyword, a page the agent found, NODE's autoplay, a site moving to the next item by itself (in-page navigation), unknown ways ignored; the line on canvas cards with NODE's picks in violet; Replay captions |
 | 51-trail-recall | Search past trails (B89): the "In your trails" group in the CommandBar ("after the memex page" finds the next page in another trail), picking switches trail and selects the card with a ring; the canvas search list ("memex today") under its heading, after the web choices; a timeline-only page shows its row marked; words that say nothing find nothing |
 | 52-media-moments | Media moments (B88): ⌘⇧K start then end saves a moment card with captions and pauses; ⌘⇧J saves the last 30 seconds with the caption cues; with a loop set one press saves the loop; the card (Moment, times, captions, Play, Ask for ID); the timeline says Moment; changing the times; Ask for ID makes a "raises" question; Play seeks, plays and loops the range; no video, nothing saved |
+| 53-saved-copies | Saved copies (B87): File → Save a Copy of This Page makes the page a card with an MHTML copy named by its SHA-256 and its text; an unchanged page keeps one copy; sign-in pages never; the card line opens the copy, and a copy changed on disk is not opened; Save a copy on a card with no tab; Keep copies in the trail's … menu; sharing lists copies, and sends them in “<name> copies” only when ticked; opening the file brings matching copies in and marks a changed one |
 | 21-rules-editor | Site rules editor: list with plain summaries, Rule for this site, saving and the rule taking effect (autoplay off after reload), invalid pattern refused with the file unchanged, hand-written fields kept, move and delete |
 | 20-first-run-and-help | Welcome screen on first start (page views hidden), choices saved with keys encrypted, not shown again; new tab page with most visited pages and its search box; a custom new tab page; Copy diagnostics without keys; Help menu |
 | 19-browser-basics | Error page for a failed load, page-stopped page after a crash, reopen closed tab, Tab 1 and Next Tab, right-click menu items for links, images, text and the page, two downloads (second renamed), Library → Downloads, Save as PDF, sleeping idle tabs and waking one, tabs restored after a restart (asleep except the active one) |