feat(privacy): strip tracking parameters from links on paste, send and render (#103)

Shared links routinely carry ad/analytics identifiers (utm_*, fbclid, gclid,
YouTube si=, Amazon ref=/tag=, X s=/t=, TikTok _r/_t, …) that tie every
recipient's click back to the person who shared the link. New
src/app/utils/urlTracking.ts is a pure, local stripper: a global list +
utm_/pk_/matomo_ prefixes, plus host-scoped rules so e.g. `si` is only
removed on youtube/spotify. matrix.to and non-http(s) schemes are never
rewritten; unparseable input is returned unchanged; Amazon's `th`/`psc`
variant selectors are deliberately kept. 13 unit tests.

Wired at three points, all behind a new Settings → Privacy toggle
(`stripTrackingParams`, default on):
- paste: plain-text pastes are cleaned and re-inserted through Slate's own
  insertData so multi-line pastes still split into paragraphs;
- send: RoomInput submit + schedule paths and MessageEditor saves clean both
  `body` and `formatted_body` (the HTML variant unescapes `&` around each
  URL and re-escapes it so the markup is untouched);
- render: linkify `formatHref`/`format` and explicit `<a href>` in
  formatted_body are cleaned, so links sent from other clients are safe to
  click too. LINKIFY_OPTS is spread into memoised per-timeline objects, so
  the toggle is a module flag kept current by ClientNonUIFeatures.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/features/room/RoomInput.tsx

@@ -140,6 +140,7 @@ import { DraftIndicator } from './DraftIndicator';
 import { scheduledMessagesAtom } from '../../state/scheduledMessages';
 import { createErrorToast, toastQueueAtom } from '../../state/toast';
 import { getThreadDraftKey } from '../../state/room/thread';
+import { stripTrackingParamsInHtml, stripTrackingParamsInText } from '../../utils/urlTracking';
 
 const GifPicker = React.lazy(() =>
   import('../../components/GifPicker').then((m) => ({ default: m.GifPicker })),
@@ -258,6 +259,8 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
     // [Gitea #68] The GIF picker is opt-in (searches go to Giphy); hide the
     // toolbar button entirely when it's off so it never opens an empty popover.
     const [gifPickerEnabled] = useSetting(settingsAtom, 'gifPickerEnabled');
+    // [Gitea #103] Privacy: drop tracking params from links on paste and on send.
+    const [stripTracking] = useSetting(settingsAtom, 'stripTrackingParams');
     const showGif = (composerToolbarButtons?.showGif ?? true) && gifPickerEnabled;
     const showLocation = composerToolbarButtons?.showLocation ?? true;
     const showPoll = composerToolbarButtons?.showPoll ?? true;
@@ -389,7 +392,25 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
       [setSelectedFiles, room],
     );
     const pickFile = useFilePicker(handleFiles, true);
-    const handlePaste = useFilePasteHandler(handleFiles);
+    const handleFilePaste = useFilePasteHandler(handleFiles);
+    const handlePaste = useCallback<React.ClipboardEventHandler>(
+      (evt) => {
+        handleFilePaste(evt);
+        if (evt.defaultPrevented || !stripTracking) return;
+        const text = evt.clipboardData?.getData('text/plain');
+        if (!text) return;
+        const cleaned = stripTrackingParamsInText(text);
+        if (cleaned === text) return;
+        // Re-run Slate's own plain-text insertion with the cleaned string so
+        // multi-line pastes still split into paragraphs exactly as before.
+        if (typeof DataTransfer === 'undefined') return;
+        evt.preventDefault();
+        const dt = new DataTransfer();
+        dt.setData('text/plain', cleaned);
+        ReactEditor.insertData(editor, dt);
+      },
+      [handleFilePaste, stripTracking, editor],
+    );
     const dropZoneVisible = useFileDropZone(fileDropContainerRef, handleFiles);
     const { gifApiKey } = useClientConfig();
     const gifBtnRef = useRef<HTMLButtonElement>(null);
@@ -623,6 +644,10 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
         plainText = trimCommand(commandName, plainText);
         customHtml = trimCommand(commandName, customHtml);
       }
+      if (stripTracking) {
+        plainText = stripTrackingParamsInText(plainText);
+        customHtml = stripTrackingParamsInHtml(customHtml);
+      }
       if (commandName === Command.Me) {
         msgType = MsgType.Emote;
       } else if (commandName === Command.Notice) {
@@ -718,6 +743,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
       isMarkdown,
       commands,
       setToast,
+      stripTracking,
     ]);
 
     /**
@@ -740,8 +766,8 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
       );
       if (plainText === '') return null;
 
-      const body = plainText;
+      const body = stripTracking ? stripTrackingParamsInText(plainText) : plainText;
-      const formattedBody = customHtml;
+      const formattedBody = stripTracking ? stripTrackingParamsInHtml(customHtml) : customHtml;
       const mentionData = getMentions(mx, roomId, editor);
 
       const content: IContent = {
@@ -769,7 +795,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
         }
       }
       return content;
-    }, [editor, isMarkdown, mx, roomId, replyDraft]);
+    }, [editor, isMarkdown, mx, roomId, replyDraft, stripTracking]);
 
     const handleScheduleClick = useCallback(() => {
       // Defense in depth: scheduling sends an unencrypted m.room.message, so never

src/app/features/room/message/MessageEditor.tsx

@@ -58,6 +58,7 @@ import {
   trimReplyFromFormattedBody,
 } from '../../../utils/room';
 import { mobileOrTablet } from '../../../utils/user-agent';
+import { stripTrackingParamsInHtml, stripTrackingParamsInText } from '../../../utils/urlTracking';
 import { useComposingCheck } from '../../../hooks/useComposingCheck';
 
 type MessageEditorProps = {
@@ -87,6 +88,8 @@ export const MessageEditor = as<'div', MessageEditorProps>(
     const [enterForNewline] = useSetting(settingsAtom, 'enterForNewline');
     const [globalToolbar] = useSetting(settingsAtom, 'editorToolbar');
     const [isMarkdown] = useSetting(settingsAtom, 'isMarkdown');
+    // [Gitea #103] Same paste/send stripping as RoomInput, for edits.
+    const [stripTracking] = useSetting(settingsAtom, 'stripTrackingParams');
     const [toolbar, setToolbar] = useState(globalToolbar);
     const isComposing = useComposingCheck();
 
@@ -117,8 +120,8 @@ export const MessageEditor = as<'div', MessageEditorProps>(
 
     const [saveState, save] = useAsyncCallback(
       useCallback(async () => {
-        const plainText = toPlainText(editor.children, isMarkdown).trim();
+        const rawPlainText = toPlainText(editor.children, isMarkdown).trim();
-        const customHtml = trimCustomHtml(
+        const rawCustomHtml = trimCustomHtml(
           toMatrixCustomHTML(editor.children, {
             allowTextFormatting: true,
             allowBlockMarkdown: isMarkdown,
@@ -126,6 +129,8 @@ export const MessageEditor = as<'div', MessageEditorProps>(
             allowMath: true,
           }),
         );
+        const plainText = stripTracking ? stripTrackingParamsInText(rawPlainText) : rawPlainText;
+        const customHtml = stripTracking ? stripTrackingParamsInHtml(rawCustomHtml) : rawCustomHtml;
 
         // Media caption edit: preserve the media, change only body/formatted_body.
         // An empty caption is valid (it removes the caption → body falls back to
@@ -239,6 +244,7 @@ export const MessageEditor = as<'div', MessageEditorProps>(
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         return mx.sendMessage(roomId, content as any);
       }, [
+        stripTracking,
         mx,
         editor,
         roomId,

src/app/features/settings/general/General.tsx

@@ -1439,10 +1439,18 @@ function Privacy() {
     settingsAtom,
     'warnOnUnverifiedDevices',
   );
+  const [stripTracking, setStripTracking] = useSetting(settingsAtom, 'stripTrackingParams');
 
   return (
     <Box direction="Column" gap="100">
       <Text size="L400">Privacy</Text>
+      <SequenceCard className={SequenceCardStyle} variant="SurfaceVariant" direction="Column">
+        <SettingTile
+          title="Strip Tracking Parameters from Links"
+          description="Remove utm_, fbclid, YouTube si= and other ad/analytics identifiers from links you paste or send, and from links shown in chat. Runs entirely on this device."
+          after={<Switch variant="Primary" value={stripTracking} onChange={setStripTracking} />}
+        />
+      </SequenceCard>
       <SequenceCard className={SequenceCardStyle} variant="SurfaceVariant" direction="Column">
         <SettingTile
           title="Hide Typing & Read Receipts"

src/app/pages/client/ClientNonUIFeatures.tsx

@@ -20,6 +20,7 @@ import { notificationPermission, setFavicon, showOsNotification } from '../../ut
 import { NOTIFICATION_SOUND_MAP } from '../../utils/notificationSounds';
 import { useSetting } from '../../state/hooks/settings';
 import { settingsAtom } from '../../state/settings';
+import { setStripTrackingOnRender } from '../../plugins/react-custom-html-parser';
 import { allInvitesAtom } from '../../state/room-list/inviteList';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { useHydrateMsgDrafts } from '../../hooks/useHydrateMsgDrafts';
@@ -90,6 +91,11 @@ function SystemEmojiFeature() {
 
 function PageZoomFeature() {
   const [pageZoom] = useSetting(settingsAtom, 'pageZoom');
+  // [Gitea #103] Mirror the privacy toggle into the html parser's module flag.
+  const [stripTracking] = useSetting(settingsAtom, 'stripTrackingParams');
+  useEffect(() => {
+    setStripTrackingOnRender(stripTracking);
+  }, [stripTracking]);
 
   if (pageZoom === 100) {
     document.documentElement.style.removeProperty('font-size');

src/app/plugins/react-custom-html-parser.tsx

@@ -22,6 +22,7 @@ import { IntermediateRepresentation, Opts as LinkifyOpts, OptFn } from 'linkifyj
 import Linkify from 'linkify-react';
 import { ErrorBoundary } from 'react-error-boundary';
 import { ChildNode } from 'domhandler';
+import { stripTrackingParams } from '../utils/urlTracking';
 import * as css from '../styles/CustomHtml.css';
 import {
   getMxIdLocalPart,
@@ -106,11 +107,30 @@ const renderMath = (
 
 const EMOJI_REG_G = new RegExp(`${URL_NEG_LB}(${EMOJI_PATTERN})`, 'g');
 
+// [Gitea #103] Render-time tracking-param stripping. LINKIFY_OPTS is spread
+// into memoised per-timeline option objects, so the toggle lives in a module
+// flag that the format callbacks read lazily on every render; the setting's
+// subscriber (ClientNonUIFeatures) keeps it current.
+let stripTrackingOnRender = true;
+export const setStripTrackingOnRender = (enabled: boolean): void => {
+  stripTrackingOnRender = enabled;
+};
+const cleanHref = (href: string): string =>
+  stripTrackingOnRender ? stripTrackingParams(href) : href;
+
 export const LINKIFY_OPTS: LinkifyOpts = {
   attributes: {
     target: '_blank',
     rel: 'noreferrer noopener',
   },
+  formatHref: {
+    url: cleanHref,
+  },
+  // Only the visible text of bare URLs is a URL, so cleaning it keeps the
+  // label honest about where the link goes.
+  format: {
+    url: cleanHref,
+  },
   validate: {
     url: (value) => /^(https?|ftp|mailto|magnet):/.test(value),
   },
@@ -393,6 +413,12 @@ export const getReactCustomHtmlParser = (
     replace: (domNode) => {
       if (domNode instanceof Element && 'name' in domNode) {
         const { name, attribs, children, parent } = domNode;
+        // [Gitea #103] Clean explicit <a href> targets from formatted_body
+        // before any branch below (mention detection, default render) sees them.
+        if (name === 'a' && stripTrackingOnRender && typeof attribs.href === 'string') {
+          const cleaned = stripTrackingParams(attribs.href);
+          if (cleaned !== attribs.href) attribs.href = cleaned;
+        }
         const props = attributesToProps(attribs);
 
         if (name === 'h1') {

src/app/state/settings.ts

@@ -263,6 +263,10 @@ export interface Settings {
 
   warnOnUnverifiedDevices: boolean;
 
+  // [Gitea #103] Remove utm_/fbclid/… tracking params from links you paste or
+  // send, and from links rendered in the timeline. Local only.
+  stripTrackingParams: boolean;
+
   pauseAnimations: boolean;
 
   composerToolbarButtons: ComposerToolbarSettings;
@@ -372,6 +376,8 @@ const defaultSettings: Settings = {
 
   warnOnUnverifiedDevices: false,
 
+  stripTrackingParams: true,
+
   pauseAnimations: false,
 
   composerToolbarButtons: DEFAULT_COMPOSER_TOOLBAR,

src/app/utils/urlTracking.test.ts

@@ -0,0 +1,111 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import {
+  stripTrackingParams,
+  stripTrackingParamsInHtml,
+  stripTrackingParamsInText,
+} from './urlTracking';
+
+describe('stripTrackingParams', () => {
+  it('removes utm_* and known global params, keeps the rest', () => {
+    const out = stripTrackingParams(
+      'https://example.com/a?utm_source=x&utm_medium=y&fbclid=abc&page=2&gclid=1',
+    );
+    assert.equal(out, 'https://example.com/a?page=2');
+  });
+
+  it('drops the dangling ? when every param was tracking', () => {
+    assert.equal(
+      stripTrackingParams('https://example.com/a?utm_source=x'),
+      'https://example.com/a',
+    );
+  });
+
+  it('returns the identical string when nothing changed', () => {
+    const url = 'https://example.com/a?page=2#frag';
+    assert.equal(stripTrackingParams(url), url);
+  });
+
+  it('preserves the fragment', () => {
+    assert.equal(
+      stripTrackingParams('https://example.com/a?utm_source=x#section-3'),
+      'https://example.com/a#section-3',
+    );
+  });
+
+  it('applies host rules only on that host', () => {
+    assert.equal(
+      stripTrackingParams('https://youtu.be/dQw4w9WgXcQ?si=abc123&t=42'),
+      'https://youtu.be/dQw4w9WgXcQ?t=42',
+    );
+    assert.equal(
+      stripTrackingParams('https://www.youtube.com/watch?v=dQw4w9WgXcQ&feature=share&si=x'),
+      'https://www.youtube.com/watch?v=dQw4w9WgXcQ',
+    );
+    // `si` is not tracking elsewhere.
+    const other = 'https://example.com/?si=keep';
+    assert.equal(stripTrackingParams(other), other);
+  });
+
+  it('strips amazon affiliate/telemetry params and the /ref= path segment but keeps variant selectors', () => {
+    assert.equal(
+      stripTrackingParams(
+        'https://www.amazon.com/dp/B000000000/ref=sr_1_3?crid=ABC&keywords=x&qid=1&sr=8-3&tag=aff-20&th=1&psc=1&pd_rd_r=zz',
+      ),
+      'https://www.amazon.com/dp/B000000000?keywords=x&th=1&psc=1',
+    );
+  });
+
+  it('never rewrites matrix.to permalinks or non-http schemes', () => {
+    const permalink = 'https://matrix.to/#/!room:example.org/$event?via=example.org&utm_source=x';
+    assert.equal(stripTrackingParams(permalink), permalink);
+    assert.equal(
+      stripTrackingParams('mxc://example.org/abc?utm_source=x'),
+      'mxc://example.org/abc?utm_source=x',
+    );
+    assert.equal(stripTrackingParams('mailto:a@b.c?utm_source=x'), 'mailto:a@b.c?utm_source=x');
+  });
+
+  it('returns unparseable input unchanged', () => {
+    assert.equal(stripTrackingParams('https://'), 'https://');
+    assert.equal(stripTrackingParams('not a url'), 'not a url');
+  });
+
+  it('is idempotent', () => {
+    const once = stripTrackingParams('https://x.com/user/status/1?s=20&t=abc');
+    assert.equal(once, 'https://x.com/user/status/1');
+    assert.equal(stripTrackingParams(once), once);
+  });
+});
+
+describe('stripTrackingParamsInText', () => {
+  it('cleans every URL in a block of text and keeps trailing punctuation', () => {
+    const text =
+      'see https://a.example/p?utm_source=x. and (https://b.example/?id=1&fbclid=2) plus https://c.example/?keep=1';
+    assert.equal(
+      stripTrackingParamsInText(text),
+      'see https://a.example/p. and (https://b.example/?id=1) plus https://c.example/?keep=1',
+    );
+  });
+
+  it('returns the identical string when no URL changed', () => {
+    const text = 'nothing https://c.example/?keep=1 here';
+    assert.equal(stripTrackingParamsInText(text), text);
+  });
+});
+
+describe('stripTrackingParamsInHtml', () => {
+  it('unescapes & for parsing and re-escapes in the output', () => {
+    const html =
+      '<a href="https://a.example/p?id=1&amp;utm_source=x&amp;page=2">https://a.example/p?id=1&amp;utm_source=x&amp;page=2</a>';
+    assert.equal(
+      stripTrackingParamsInHtml(html),
+      '<a href="https://a.example/p?id=1&amp;page=2">https://a.example/p?id=1&amp;page=2</a>',
+    );
+  });
+
+  it('leaves markup untouched when nothing is stripped', () => {
+    const html = '<p>hi <a href="https://a.example/?x=1">link</a></p>';
+    assert.equal(stripTrackingParamsInHtml(html), html);
+  });
+});

src/app/utils/urlTracking.ts

@@ -0,0 +1,233 @@
+/**
+ * [Gitea #103] Tracking-parameter stripping.
+ *
+ * Shared links routinely carry ad/analytics identifiers (`utm_*`, `fbclid`,
+ * YouTube `si=`, Amazon `ref=`…) that tie every recipient's click back to the
+ * person who shared the link. Everything here is pure and local: a URL goes in,
+ * the same URL minus known tracking params comes out. Unknown params are never
+ * touched, and anything that fails to parse is returned unchanged.
+ */
+
+// Exact query-parameter names stripped on every host.
+const GLOBAL_PARAMS = new Set([
+  // Google Ads / Analytics
+  'gclid',
+  'gclsrc',
+  'dclid',
+  'gbraid',
+  'wbraid',
+  'srsltid',
+  '_ga',
+  '_gl',
+  // Meta / Instagram
+  'fbclid',
+  'igshid',
+  'igsh',
+  // Microsoft / Bing
+  'msclkid',
+  // X / Twitter
+  'twclid',
+  // TikTok
+  'ttclid',
+  // Yandex
+  'yclid',
+  // Mailchimp
+  'mc_cid',
+  'mc_eid',
+  // HubSpot
+  '_hsenc',
+  '_hsmi',
+  'hsCtaTracking',
+  // Marketo / Adobe
+  'mkt_tok',
+  's_kwcid',
+  'ef_id',
+  // Vero / Wicked Reports / Omeda
+  'vero_id',
+  'vero_conv',
+  'wickedid',
+  'oly_anon_id',
+  'oly_enc_id',
+  // Generic referrer tags
+  'ref_src',
+  'ref_url',
+  'spm',
+]);
+
+// Query-parameter name prefixes stripped on every host.
+const GLOBAL_PREFIXES = ['utm_', 'pk_', 'piwik_', 'matomo_'];
+
+// Host-specific params that only act as tracking on that site. Matched by
+// hostname suffix (so `www.youtube.com` and `m.youtube.com` both hit `youtube.com`).
+const AMAZON_HOSTS = [
+  'amazon.com',
+  'amazon.co.uk',
+  'amazon.de',
+  'amazon.ca',
+  'amazon.fr',
+  'amazon.co.jp',
+];
+
+const HOST_PARAMS: Array<{ hosts: string[]; params: string[]; prefixes?: string[] }> = [
+  {
+    hosts: ['youtube.com', 'youtu.be'],
+    params: ['si', 'feature', 'pp'],
+  },
+  {
+    hosts: AMAZON_HOSTS,
+    // Affiliate + search-result telemetry only. `th`/`psc` pick the product
+    // variant that loads and are deliberately NOT stripped.
+    params: [
+      'ref',
+      'ref_',
+      'tag',
+      'linkCode',
+      'linkId',
+      'crid',
+      'sprefix',
+      'qid',
+      'sr',
+      'dib',
+      'dib_tag',
+      'content-id',
+    ],
+    prefixes: ['pd_rd_', 'pf_rd_'],
+  },
+  {
+    hosts: ['x.com', 'twitter.com'],
+    params: ['s', 't', 'ref_src'],
+  },
+  {
+    hosts: ['spotify.com'],
+    params: ['si', 'nd'],
+  },
+  {
+    hosts: ['reddit.com'],
+    params: ['share_id', 'rdt', 'context'],
+  },
+  {
+    hosts: ['tiktok.com'],
+    params: ['_r', '_t', 'is_from_webapp', 'sender_device', 'web_id'],
+  },
+  {
+    hosts: ['instagram.com'],
+    params: ['igsh', 'img_index'],
+  },
+  {
+    hosts: ['threads.net'],
+    params: ['igshid'],
+  },
+  {
+    hosts: ['bilibili.com'],
+    params: ['spm_id_from', 'vd_source'],
+  },
+  {
+    hosts: ['ebay.com', 'ebay.co.uk', 'ebay.de'],
+    params: ['_trkparms', '_trksid', 'mkcid', 'mkevt', 'mkrid', 'campid', 'toolid', 'customid'],
+  },
+];
+
+// Hosts whose URLs are never rewritten: Matrix permalinks encode room/event
+// ids after a fragment and have no tracking, but a false positive would break
+// navigation, so leave the whole family alone.
+const SKIP_HOSTS = ['matrix.to'];
+
+const hostMatches = (hostname: string, suffixes: string[]): boolean =>
+  suffixes.some((s) => hostname === s || hostname.endsWith(`.${s}`));
+
+const isTrackingParam = (name: string, hostname: string): boolean => {
+  if (GLOBAL_PARAMS.has(name)) return true;
+  const lower = name.toLowerCase();
+  if (GLOBAL_PREFIXES.some((p) => lower.startsWith(p))) return true;
+  return HOST_PARAMS.some(
+    (rule) =>
+      hostMatches(hostname, rule.hosts) &&
+      (rule.params.includes(name) || (rule.prefixes ?? []).some((p) => name.startsWith(p))),
+  );
+};
+
+/**
+ * Remove known tracking query parameters from an `http(s)` URL. Returns the
+ * input unchanged when it is not an http(s) URL, cannot be parsed, or has
+ * nothing to strip — so callers can compare by identity to know whether
+ * anything happened. Never touches the fragment or the path (except Amazon's
+ * `/ref=…` path segment, which is a pure referrer tag).
+ */
+export const stripTrackingParams = (url: string): string => {
+  if (!/^https?:\/\//i.test(url)) return url;
+  let parsed: URL;
+  try {
+    parsed = new URL(url);
+  } catch {
+    return url;
+  }
+  const hostname = parsed.hostname.toLowerCase();
+  if (hostMatches(hostname, SKIP_HOSTS)) return url;
+
+  let changed = false;
+  const params = parsed.searchParams;
+  Array.from(params.keys()).forEach((name) => {
+    if (isTrackingParam(name, hostname)) {
+      params.delete(name);
+      changed = true;
+    }
+  });
+
+  if (hostMatches(hostname, AMAZON_HOSTS)) {
+    const cleanedPath = parsed.pathname.replace(/\/ref=[^/]*/i, '');
+    if (cleanedPath !== parsed.pathname) {
+      parsed.pathname = cleanedPath;
+      changed = true;
+    }
+  }
+
+  if (!changed) return url;
+  // URLSearchParams re-serialises the remaining query; when it is now empty,
+  // drop the dangling `?` entirely.
+  if (params.toString() === '') parsed.search = '';
+  return parsed.toString();
+};
+
+// Matches an http(s) URL inside free text, stopping before whitespace, quotes,
+// angle brackets or a closing paren/bracket. Trailing sentence punctuation is
+// trimmed separately so "see https://a.b/?utm_source=x." keeps its full stop.
+const URL_IN_TEXT = /https?:\/\/[^\s<>"'()[\]]+/gi;
+const TRAILING_PUNCT = /[.,;:!?]+$/;
+
+/**
+ * Strip tracking params from every http(s) URL found in a block of text (the
+ * plaintext `body`, or a pasted clipboard string). Returns the input unchanged
+ * if nothing was stripped.
+ */
+export const stripTrackingParamsInText = (text: string): string => {
+  let changed = false;
+  const out = text.replace(URL_IN_TEXT, (match) => {
+    const punct = match.match(TRAILING_PUNCT)?.[0] ?? '';
+    const url = punct ? match.slice(0, -punct.length) : match;
+    const cleaned = stripTrackingParams(url);
+    if (cleaned === url) return match;
+    changed = true;
+    return cleaned + punct;
+  });
+  return changed ? out : text;
+};
+
+/**
+ * Same as `stripTrackingParamsInText` for an HTML string (`formatted_body`),
+ * where `&` inside attribute values and text is escaped as `&amp;`. Each URL is
+ * unescaped before stripping and re-escaped after, so the surrounding markup is
+ * left byte-for-byte intact.
+ */
+export const stripTrackingParamsInHtml = (html: string): string => {
+  let changed = false;
+  const out = html.replace(URL_IN_TEXT, (match) => {
+    const punct = match.match(TRAILING_PUNCT)?.[0] ?? '';
+    const raw = punct ? match.slice(0, -punct.length) : match;
+    const url = raw.replace(/&amp;/g, '&');
+    const cleaned = stripTrackingParams(url);
+    if (cleaned === url) return match;
+    changed = true;
+    return cleaned.replace(/&/g, '&amp;') + punct;
+  });
+  return changed ? out : html;
+};