diff --git a/static/css/components/shareModal.css b/static/css/components/shareModal.css
index 48b9db26..688f7c8d 100644
--- a/static/css/components/shareModal.css
+++ b/static/css/components/shareModal.css
@@ -138,6 +138,22 @@
     min-width: 0;
 }
 
+/* "Invite by email" synthetic suggestion (PR 11.3). The hint label sits
+   to the right of the pending-email vignette and stays muted so the
+   row reads as auxiliary — the action it commits is more consequential
+   than a regular contact pick. */
+.smd-suggestion-item--email {
+    border-top: 1px solid var(--color-border);
+}
+
+.smd-suggestion-hint {
+    margin-left: auto;
+    color: var(--color-text-faint);
+    font-size: 12px;
+    font-style: italic;
+    flex-shrink: 0;
+}
+
 /* Role picker beside the search box */
 .smd-role-select {
     padding: 9px 10px;
diff --git a/static/css/components/userVignette.css b/static/css/components/userVignette.css
index b11bb042..121869e2 100644
--- a/static/css/components/userVignette.css
+++ b/static/css/components/userVignette.css
@@ -32,6 +32,8 @@
     width: 24px;
     height: 24px;
     font-size: 10px;
+    /* Anchor for the bottom-right `__origin` badge. */
+    position: relative;
 }
 
 .user-vignette__name {
@@ -176,3 +178,37 @@
     width: 100%;
     height: 100%;
 }
+
+/* ── Origin badge (external-user marker) ───────────────────────────────────
+ * Tiny FontAwesome icon overlaid on the bottom-right of the avatar circle.
+ * Shown ONLY for external users — internal users render the bare avatar
+ * (Ed's "external only" preference: quiet UI for the common case).
+ *
+ * The white background ring lifts the icon off coloured avatars so it
+ * stays readable across the full palette.                                  */
+
+.user-vignette__origin {
+    position: absolute;
+    /* Bottom-right corner, slightly tucked past the avatar's edge. */
+    right: -2px;
+    bottom: -2px;
+    /* Scale to ~40% of avatar diameter via em — the parent's font-size
+       changes per size variant, so the badge naturally tracks. */
+    font-size: 0.9em;
+    line-height: 1;
+    background: var(--color-bg-surface);
+    color: var(--color-text-secondary);
+    border-radius: 50%;
+    /* Halo ring so the icon visually detaches from coloured avatars. */
+    box-shadow: 0 0 0 1.5px var(--color-bg-surface);
+    /* Don't intercept hover events on the avatar itself. */
+    pointer-events: auto;
+}
+
+.user-vignette__origin--external {
+    color: var(--color-warning-orange-text);
+}
+
+.user-vignette__origin.hidden {
+    display: none;
+}
diff --git a/static/js/app/authSession.js b/static/js/app/authSession.js
index b02fe59d..4d3ab246 100644
--- a/static/js/app/authSession.js
+++ b/static/js/app/authSession.js
@@ -3,7 +3,6 @@
  */
 
 import { getCsrfHeaders } from '../core/csrf.js';
-import { loadFiles } from './filesView.js';
 import { updateStorageUsageDisplay } from './main.js';
 import { app } from './state.js';
 import { ui } from './ui.js';
@@ -40,6 +39,7 @@ async function refreshUserData() {
         console.log('Storage from server: used=', userData.storage_used_bytes, 'quota=', userData.storage_quota_bytes);
 
         localStorage.setItem(USER_DATA_KEY, JSON.stringify(userData));
+        app.isExternalUser = !!userData.is_external;
         updateStorageUsageDisplay(userData);
         return userData;
     } catch (error) {
@@ -93,8 +93,15 @@ async function checkAuthentication() {
         // Check session validity by calling /api/auth/me (cookie auto-sent)
         console.log('Checking session via /api/auth/me...');
 
+        /** @type {User} */
         /** @type {User} */
         const userData = JSON.parse(localStorage.getItem(USER_DATA_KEY) || '{}');
+        // Restore the external-user flag eagerly from cache so the
+        // resolveHomeFolder short-circuit fires before the /api/auth/me
+        // refresh completes. The parse may produce a sparse object on
+        // first load — `is_external` defaulting to falsy is correct
+        // for the internal-user-by-default contract.
+        app.isExternalUser = !!userData.is_external;
         if (userData.username) {
             // We have cached user data — render immediately, refresh in background
             updateUserMenuData();
@@ -134,14 +141,22 @@ async function checkAuthentication() {
             await resolveHomeFolder();
             window.dispatchEvent(new CustomEvent('authenticationDone'));
         } else {
-            // No cached user data — must verify session from server
+            // No cached user data — must verify session from server.
+            // This is the first-load path for magic-link redemptions
+            // (cookies set server-side, no prior localStorage).
             console.log('No cached user data, fetching from server');
             try {
                 const freshData = await refreshUserData();
                 if (freshData?.username) {
                     updateUserMenuData();
                     updateStorageUsageDisplay(freshData);
-                    resolveHomeFolder().then(() => loadFiles());
+                    await resolveHomeFolder();
+                    // Defer to the `authenticationDone` listener in main.js
+                    // so the hash-driven section + path init runs in one
+                    // place (was previously a `loadFiles()` here which
+                    // bypassed the hash context and produced
+                    // `/api/folders//resources` for external users).
+                    window.dispatchEvent(new CustomEvent('authenticationDone'));
                 } else {
                     console.warn('Could not retrieve user data, redirecting to login');
                     localStorage.removeItem(USER_DATA_KEY);
@@ -162,6 +177,16 @@ async function checkAuthentication() {
 
 async function resolveHomeFolder() {
     if (app.userHomeFolderId) return;
+    // External users (grant-only recipients) do not own a home folder
+    // by design — see `HomeFolderLifecycleHook::provision_if_needed`
+    // which short-circuits on `is_external`. Skip the fetch + leave
+    // `userHomeFolderId` null so downstream code knows to land them on
+    // /#/sharedwithme instead of /files.
+    if (app.isExternalUser) {
+        console.log('External user — skipping home-folder resolution');
+        app.breadcrumbPath = [];
+        return;
+    }
     try {
         const response = await fetch('/api/folders', {
             credentials: 'same-origin'
diff --git a/static/js/app/filesView.js b/static/js/app/filesView.js
index 33100d85..39cafa5f 100644
--- a/static/js/app/filesView.js
+++ b/static/js/app/filesView.js
@@ -405,6 +405,17 @@ async function loadFiles(options = { insertHistory: true }) {
     try {
         if (!app.userHomeFolderId) await resolveHomeFolder();
 
+        // External users have no home folder. If they land on /files
+        // without a specific folder id in the URL, redirect them to
+        // /#/sharedwithme — their actual landing page. This guards
+        // against `fetchResourcesPage('')` building `/api/folders//resources`.
+        if (app.isExternalUser && (!app.currentPath || app.currentPath === '')) {
+            clearTimeout(spinnerTimeout);
+            _loading = false;
+            window.location.hash = '#/sharedwithme';
+            return;
+        }
+
         // Resolve path to home folder when none is set
         if (!app.currentPath || app.currentPath === '') {
             if (app.userHomeFolderId) {
diff --git a/static/js/app/main.js b/static/js/app/main.js
index f2328cd4..8e1e6678 100644
--- a/static/js/app/main.js
+++ b/static/js/app/main.js
@@ -407,8 +407,11 @@ function setupActionsBarDelegation() {
 function deserializeHash() {
     const hashContext = /** type {OxiContext} */ {};
 
+    // External users have no home folder; default them to /#/sharedwithme
+    // (their actual landing) so the URL bar reflects what they'll see.
+    // Internal users default to the Files section.
     // FIXME rename files into drive ?
-    hashContext.section = 'files';
+    hashContext.section = app.isExternalUser ? 'sharedwithme' : 'files';
 
     const hash_elements = window.location.hash.split('/');
 
diff --git a/static/js/app/navigation.js b/static/js/app/navigation.js
index 09eaab5b..88b0e64a 100644
--- a/static/js/app/navigation.js
+++ b/static/js/app/navigation.js
@@ -299,9 +299,15 @@ function switchToFilesSection() {
     //reset files view + remove any error
     ui.resetFilesList();
 
-    // Reset to home folder and update breadcrumb
-    app.currentPath = app.userHomeFolderId || '';
-    app.breadcrumbPath = [];
+    // Reset to home folder and update breadcrumb. External users have no
+    // home — leave `currentPath` as the caller set it (e.g. the magic-link
+    // landing's hash context) so loadFiles() doesn't fall through to
+    // `/api/folders//resources`. If `currentPath` is still empty by the
+    // time loadFiles() runs, it self-redirects to /#/sharedwithme.
+    if (!app.isExternalUser) {
+        app.currentPath = app.userHomeFolderId || '';
+        app.breadcrumbPath = [];
+    }
     ui.updateBreadcrumb();
     if (batchToolbar) batchToolbar.clear();
 
diff --git a/static/js/app/state.js b/static/js/app/state.js
index 3d030c84..2d300336 100644
--- a/static/js/app/state.js
+++ b/static/js/app/state.js
@@ -59,6 +59,16 @@ export const app = {
     /** @type {string | null} */
     userHomeFolderName: null,
 
+    /**
+     * `true` when the authenticated caller is an external (grant-only)
+     * user. Externals don't own a home folder, can't enumerate users,
+     * and land on `/#/sharedwithme` by default. Set by `refreshUserData`
+     * and the cached-data load path from the `is_external` field of
+     * `/api/auth/me`'s response.
+     * @type {boolean}
+     */
+    isExternalUser: false,
+
     /** @type {Array<{id: string, name: string}>} */
     breadcrumbPath: [], // Array of {id, name} tracking folder navigation hierarchy
 
diff --git a/static/js/components/pendingEmailVignette.js b/static/js/components/pendingEmailVignette.js
new file mode 100644
index 00000000..a0c9e81d
--- /dev/null
+++ b/static/js/components/pendingEmailVignette.js
@@ -0,0 +1,70 @@
+// @ts-check
+
+/**
+ * PendingEmailVignette — visual for an external invite *before* the
+ * server has resolved (or lazily created) the recipient user.
+ *
+ * Used by the share modal's email-input UX:
+ *   1. The user types an address in the search input.
+ *   2. When the address matches no existing contact but parses as an
+ *      email, the dropdown surfaces an "Invite by email" suggestion
+ *      rendered with this vignette.
+ *   3. Clicking the suggestion stages an email-typed chip that also
+ *      uses this vignette.
+ *   4. On Apply, the modal POSTs `subject.type=email` and reloads the
+ *      grant list — at which point the resolved real userId takes
+ *      over via the regular `createUserVignette`, which paints the
+ *      same `fa-building-circle-xmark` badge (PR 11.2). Visual
+ *      continuity is intentional: the chip's look doesn't change
+ *      across the commit boundary.
+ *
+ * Reuses the userVignette CSS so size variants (xs/sm/md/list/lg/menu/xl),
+ * colour palette, and the external-badge styling all apply unchanged.
+ * The external badge here is FORCED visible — by definition an email
+ * we don't recognise is going to mint an external user.
+ */
+
+import { _colorIndex, _initials } from './userVignette.js';
+
+/** @typedef {'xs'|'sm'|'list'|'md'|'lg'|'menu'|'xl'} VignetteSize */
+
+/**
+ * Build a transient vignette seeded from an email address (no UUID yet).
+ *
+ * @param {string}       email
+ * @param {VignetteSize} [size='sm']
+ * @returns {HTMLElement}
+ */
+export function createPendingEmailVignette(email, size = 'sm') {
+    const trimmed = email.trim();
+    const colorIdx = _colorIndex(trimmed);
+
+    const wrapper = document.createElement('span');
+    wrapper.className = `user-vignette user-vignette--${size}`;
+
+    const avatar = document.createElement('span');
+    avatar.className = `user-vignette__avatar uv-color-${colorIdx}`;
+    // Synthesize initials: local-part initial + domain initial when
+    // possible, otherwise fall back to the first two chars.
+    const [local, domain] = trimmed.split('@');
+    const synthName = local && domain ? `${local[0]} ${domain[0]}` : trimmed.slice(0, 2);
+    avatar.textContent = _initials(synthName);
+
+    // Forced external badge — this is the whole point of the component.
+    const badge = document.createElement('i');
+    badge.className = 'user-vignette__origin user-vignette__origin--external fa-solid fa-building-circle-xmark';
+    badge.title = 'External invitation';
+    badge.setAttribute('aria-hidden', 'true');
+    avatar.appendChild(badge);
+
+    wrapper.appendChild(avatar);
+
+    // The "name" for a pending invite is just the email itself — there
+    // is no separate display name yet.
+    const nameEl = document.createElement('span');
+    nameEl.className = 'user-vignette__name';
+    nameEl.textContent = trimmed;
+    wrapper.appendChild(nameEl);
+
+    return wrapper;
+}
diff --git a/static/js/components/shareModal.js b/static/js/components/shareModal.js
index a85099e8..4706ec92 100644
--- a/static/js/components/shareModal.js
+++ b/static/js/components/shareModal.js
@@ -26,6 +26,7 @@ import { buildPasswordChip } from '../utils/passwordChip.js';
 import { groupDisplayName, groupIconClass, groupIconClassByVirtual } from './groupDisplay.js';
 import { createGroupVignette } from './groupVignette.js';
 import { Modal } from './modal.js';
+import { createPendingEmailVignette } from './pendingEmailVignette.js';
 import { createUserVignette } from './userVignette.js';
 
 /** @import {FileItem, FolderItem, Grant, ContactItem, MemberEntry, LinkEntry, DraftLink, ShareRoleEnum} from '../core/types.js' */
@@ -42,6 +43,36 @@ import { createUserVignette } from './userVignette.js';
  * @property {'group'} _kind
  */
 
+/**
+ * Synthetic "invite by email" suggestion injected at the bottom of the
+ * autocomplete dropdown when the query parses as an email and matches
+ * no existing contact. Same overall shape as `GroupSuggestion` so the
+ * staging / chip / commit paths can treat all three suggestion kinds
+ * uniformly via the `_kind` discriminator.
+ *
+ * `id` here is the email itself — it's a stable dedup key pre-resolution.
+ * The server replaces it with a real user UUID on Apply.
+ *
+ * @typedef {Object} EmailSuggestion
+ * @property {string}  id       Lowercased trimmed email (also the dedup key).
+ * @property {string}  email    Display form (lowercased trimmed).
+ * @property {'email'} _kind
+ */
+
+/**
+ * Permissive client-side email regex — matches anything with at least
+ * one non-whitespace local-part, an `@`, and a domain with a dot.
+ * The server's `normalize_email` is the authority; this is just enough
+ * to decide whether to surface the synthetic "invite by email"
+ * suggestion in the dropdown.
+ *
+ * @param {string} q
+ * @returns {boolean}
+ */
+function _looksLikeEmail(q) {
+    return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(q);
+}
+
 /** Permissions that belong to each role (must mirror the Rust DTO). */
 const ROLE_PERMISSIONS = {
     viewer: ['read'],
@@ -136,7 +167,7 @@ const shareModal = {
     /** @type {DraftLink[]} */
     _newLinks: [],
 
-    /** @type {Array<ContactItem | GroupSuggestion>} */
+    /** @type {Array<ContactItem | GroupSuggestion | EmailSuggestion>} */
     _stagedUsers: [],
 
     /** @type {ShareRoleEnum} */
@@ -381,9 +412,27 @@ const shareModal = {
                     }
                 })();
                 const filtered = currentUserId ? contacts.filter((c) => c.id !== currentUserId) : contacts;
+
+                // Synthesize an "invite by email" row when the query parses
+                // as an email AND no existing contact already matches that
+                // address (we don't want to compete with the existing
+                // contact suggestion). Lowercased+trimmed for the dedup
+                // key — same shape the server applies via normalize_email.
+                /** @type {EmailSuggestion[]} */
+                let emailItems = [];
+                if (_looksLikeEmail(q)) {
+                    const normalised = q.trim().toLowerCase();
+                    const existing = filtered.some((c) => (c.email ?? []).some((e) => e.email.toLowerCase() === normalised));
+                    if (!existing) {
+                        emailItems = [{ id: normalised, email: normalised, _kind: 'email' }];
+                    }
+                }
+
                 // Groups first (they're a smaller, distinctively-iconed set),
-                // then contacts. Cap at 8 combined.
-                const combined = [...groupItems, ...filtered].slice(0, 8);
+                // then contacts, then the email-invite suggestion at the
+                // bottom (it's the catch-all when nothing else matches).
+                // Cap at 8 combined.
+                const combined = [...groupItems, ...filtered, ...emailItems].slice(0, 8);
                 this._renderSuggestions(dropdown, combined, (item) => {
                     this._stageUser(item, input, dropdown, addBtn);
                 });
@@ -416,9 +465,9 @@ const shareModal = {
     },
 
     /**
-     * @param {HTMLElement}                                          container
-     * @param {Array<ContactItem | GroupSuggestion>}                 results
-     * @param {(c: ContactItem | GroupSuggestion) => void}           onSelect
+     * @param {HTMLElement}                                                          container
+     * @param {Array<ContactItem | GroupSuggestion | EmailSuggestion>}               results
+     * @param {(c: ContactItem | GroupSuggestion | EmailSuggestion) => void}         onSelect
      */
     _renderSuggestions(container, results, onSelect) {
         container.replaceChildren();
@@ -434,6 +483,14 @@ const shareModal = {
             if (c._kind === 'group') {
                 const g = /** @type {GroupSuggestion} */ (c);
                 item.appendChild(createGroupVignette(groupDisplayName(g), 'sm', { icon: groupIconClass(g) }));
+            } else if (c._kind === 'email') {
+                const e = /** @type {EmailSuggestion} */ (c);
+                item.classList.add('smd-suggestion-item--email');
+                item.appendChild(createPendingEmailVignette(e.email, 'sm'));
+                const hint = document.createElement('span');
+                hint.className = 'smd-suggestion-hint';
+                hint.textContent = i18n.t('share.inviteByEmail', 'Invite by email — invitation will be sent');
+                item.appendChild(hint);
             } else {
                 item.appendChild(createUserVignette(c.id, 'sm', { showEmail: true }));
             }
@@ -449,17 +506,25 @@ const shareModal = {
     },
 
     /**
-     * @param {ContactItem | GroupSuggestion} contact
-     * @param {HTMLInputElement}              inputEl
-     * @param {HTMLElement}                   dropdown
-     * @param {HTMLButtonElement}             addBtn
+     * @param {ContactItem | GroupSuggestion | EmailSuggestion} contact
+     * @param {HTMLInputElement}                                inputEl
+     * @param {HTMLElement}                                     dropdown
+     * @param {HTMLButtonElement}                               addBtn
      */
     _stageUser(contact, inputEl, dropdown, addBtn) {
         // Idempotent: skip duplicates and already-existing members. Match on
-        // id *and* kind so a user and a group sharing a UUID collision (in
-        // theory impossible; in practice harmless) wouldn't shadow each other.
-        const kind = contact._kind === 'group' ? 'group' : 'user';
-        const alreadyMember = this._localMembers.some((m) => m.grant.subject.id === contact.id && m.grant.subject.type === kind && m._op !== 'remove');
+        // id *and* kind so a user / group / email-invite sharing the same
+        // string value (unlikely but harmless) wouldn't shadow each other.
+        const kind = contact._kind === 'group' ? 'group' : contact._kind === 'email' ? 'email' : 'user';
+        const alreadyMember = this._localMembers.some((m) => {
+            if (m._op === 'remove') return false;
+            // Match against existing committed members on (type, id) — for
+            // email-staged members, the dedup happens via `_invitedEmail`.
+            if (kind === 'email') {
+                return m._invitedEmail?.toLowerCase() === contact.id.toLowerCase();
+            }
+            return m.grant.subject.id === contact.id && m.grant.subject.type === kind;
+        });
         const alreadyStaged = this._stagedUsers.some((u) => u.id === contact.id && (u._kind ?? 'user') === kind);
         if (alreadyMember || alreadyStaged) return;
 
@@ -497,19 +562,22 @@ const shareModal = {
             const chip = document.createElement('div');
             chip.className = 'smd-chip';
 
-            const visual =
-                c._kind === 'group'
-                    ? (() => {
-                          const g = /** @type {GroupSuggestion} */ (c);
-                          return createGroupVignette(groupDisplayName(g), 'xs', { icon: groupIconClass(g) });
-                      })()
-                    : createUserVignette(c.id, 'xs');
+            let visual;
+            if (c._kind === 'group') {
+                const g = /** @type {GroupSuggestion} */ (c);
+                visual = createGroupVignette(groupDisplayName(g), 'xs', { icon: groupIconClass(g) });
+            } else if (c._kind === 'email') {
+                const e = /** @type {EmailSuggestion} */ (c);
+                visual = createPendingEmailVignette(e.email, 'xs');
+            } else {
+                visual = createUserVignette(c.id, 'xs');
+            }
 
             const rm = document.createElement('button');
             rm.className = 'smd-chip-remove';
             rm.innerHTML = '&times;';
             rm.title = i18n.t('actions.remove', 'Remove');
-            const kind = c._kind === 'group' ? 'group' : 'user';
+            const kind = c._kind === 'group' ? 'group' : c._kind === 'email' ? 'email' : 'user';
             rm.addEventListener('click', () => {
                 this._stagedUsers = this._stagedUsers.filter((u) => !(u.id === c.id && (u._kind ?? 'user') === kind));
                 this._refreshChips();
@@ -525,7 +593,13 @@ const shareModal = {
 
     _commitStagedUsers() {
         for (const contact of this._stagedUsers) {
-            const subjectType = contact._kind === 'group' ? 'group' : 'user';
+            // Email-typed stagings carry a transient `_invitedEmail` on the
+            // resulting MemberEntry. The pre-commit MemberRow rendering
+            // (`_buildMemberRow`) and the `_applyAll` API-call branch both
+            // key off that field — they don't try to read a UUID out of
+            // `subject.id` (which is the email string in this case, not a
+            // real user UUID until the server resolves it).
+            const subjectType = contact._kind === 'group' ? 'group' : contact._kind === 'email' ? 'user' : 'user';
             /** @type {Grant} */
             const placeholderGrant = {
                 id: '', // not yet persisted
@@ -541,7 +615,8 @@ const shareModal = {
                 role: this._stagedRole,
                 _op: 'new',
                 expires_at: this._stagedExpiry,
-                _displayName: contact._kind === 'group' ? /** @type {GroupSuggestion} */ (contact).name : undefined
+                _displayName: contact._kind === 'group' ? /** @type {GroupSuggestion} */ (contact).name : undefined,
+                _invitedEmail: contact._kind === 'email' ? /** @type {EmailSuggestion} */ (contact).email : undefined
             });
         }
         this._stagedUsers = [];
@@ -616,12 +691,20 @@ const shareModal = {
         const row = document.createElement('div');
         row.className = 'smd-member-row';
 
+        // Three rendering paths:
+        //   - Group subject → group vignette
+        //   - Pre-commit email-invite (carries `_invitedEmail`) → pending
+        //     vignette seeded from the email; no UUID exists yet.
+        //   - Regular user subject → user vignette (which itself renders
+        //     the external badge automatically via systemUsers).
         const vignette =
             entry.grant.subject.type === 'group'
                 ? createGroupVignette(entry._displayName ?? entry.grant.subject.id, 'md', {
                       icon: groupIconClassByVirtual(entry._isVirtual)
                   })
-                : createUserVignette(entry.grant.subject.id, 'md');
+                : entry._invitedEmail
+                  ? createPendingEmailVignette(entry._invitedEmail, 'md')
+                  : createUserVignette(entry.grant.subject.id, 'md');
 
         const roleSelect = document.createElement('select');
         roleSelect.className = 'smd-member-role-select';
@@ -939,8 +1022,14 @@ const shareModal = {
                         expires_at: expiresIso
                     });
                 } else if (m._op === 'new') {
+                    // Email-invite path: the staged MemberEntry carries
+                    // `_invitedEmail`; the server resolves it to (or
+                    // creates) an external user and returns the actual
+                    // user_id in the grant DTO. Until `fetchOutgoingGrants`
+                    // refreshes below, the row keeps the pending vignette.
+                    const subject = m._invitedEmail ? { type: 'email', email: m._invitedEmail } : { type: m.grant.subject.type, id: m.grant.subject.id };
                     await grants.createGrant({
-                        subject: { type: m.grant.subject.type, id: m.grant.subject.id },
+                        subject,
                         resource: { type: itemType, id: item.id },
                         role: m.role,
                         expires_at: expiresIso
diff --git a/static/js/components/userVignette.js b/static/js/components/userVignette.js
index 70088abd..f6e0f6e0 100644
--- a/static/js/components/userVignette.js
+++ b/static/js/components/userVignette.js
@@ -90,6 +90,12 @@ function _applyPhoto(avatar, photoUrl, name) {
  *   When true (and showName is true), the primary email address is shown below
  *   the name in a lighter style.  Name and email are wrapped in a
  *   `.user-vignette__info` column.  Has no effect when showName is false.
+ * @property {boolean} [showOrigin=true]
+ *   When true (the default), an `is_external` badge overlays the
+ *   bottom-right of the avatar for external users only — internal
+ *   users render unchanged. Set false to suppress the badge in
+ *   contexts where the distinction would be noise (e.g. the
+ *   logged-in-user menu, where the caller is implicitly internal).
  */
 
 /**
@@ -101,7 +107,7 @@ function _applyPhoto(avatar, photoUrl, name) {
  * @param {VignetteOptions} [options]
  * @returns {HTMLElement}
  */
-export function createUserVignette(userId, size = 'sm', { showName = true, showEmail = false } = {}) {
+export function createUserVignette(userId, size = 'sm', { showName = true, showEmail = false, showOrigin = true } = {}) {
     const colorIdx = _colorIndex(userId);
 
     const wrapper = /** @type {HTMLElement} */ (document.createElement('span'));
@@ -113,6 +119,18 @@ export function createUserVignette(userId, size = 'sm', { showName = true, showE
     avatar.textContent = userId.slice(0, 2).toUpperCase();
     wrapper.appendChild(avatar);
 
+    // Origin badge (external-only — internal users render unchanged).
+    // Created hidden; revealed once `getIsExternal` resolves to true.
+    // FontAwesome glyph classes are added alongside the component
+    // class so the icon renders as a building-with-x glyph.
+    /** @type {HTMLElement | null} */
+    const originEl = showOrigin ? document.createElement('i') : null;
+    if (originEl) {
+        originEl.className = 'user-vignette__origin user-vignette__origin--external hidden fa-solid fa-building-circle-xmark';
+        originEl.setAttribute('aria-hidden', 'true');
+        avatar.appendChild(originEl);
+    }
+
     /** @type {HTMLElement | null} */
     const nameEl = showName ? document.createElement('span') : null;
 
@@ -136,18 +154,33 @@ export function createUserVignette(userId, size = 'sm', { showName = true, showE
         }
     }
 
-    // Resolve name, photo, and (when requested) email asynchronously.
-    Promise.all([systemUsers.getDisplayName(userId), systemUsers.getPhoto(userId), emailEl ? systemUsers.getEmail(userId) : Promise.resolve(null)]).then(
-        ([name, photo, email]) => {
-            if (nameEl) nameEl.textContent = name;
-            if (emailEl) emailEl.textContent = email ?? '';
-            if (photo) {
-                _applyPhoto(avatar, photo, name);
-            } else {
-                avatar.textContent = _initials(name);
+    // Resolve name, photo, email, and (when requested) is_external
+    // asynchronously. All four go through the systemUsers cache so a
+    // single fetch back-fills every facet.
+    Promise.all([
+        systemUsers.getDisplayName(userId),
+        systemUsers.getPhoto(userId),
+        emailEl ? systemUsers.getEmail(userId) : Promise.resolve(null),
+        originEl ? systemUsers.getIsExternal(userId) : Promise.resolve(false)
+    ]).then(([name, photo, email, isExternal]) => {
+        if (nameEl) nameEl.textContent = name;
+        if (emailEl) emailEl.textContent = email ?? '';
+        if (photo) {
+            _applyPhoto(avatar, photo, name);
+        } else {
+            avatar.textContent = _initials(name);
+        }
+        // Both branches above replace the avatar's children, wiping the
+        // pre-attached badge node. Re-attach AFTER the avatar's content
+        // is final so the badge sits on top.
+        if (originEl) {
+            avatar.appendChild(originEl);
+            if (isExternal) {
+                originEl.classList.remove('hidden');
+                originEl.title = 'External user';
             }
         }
-    );
+    });
 
     return wrapper;
 }
diff --git a/static/js/core/icons.js b/static/js/core/icons.js
index 2da09719..15b56daf 100644
--- a/static/js/core/icons.js
+++ b/static/js/core/icons.js
@@ -73,6 +73,14 @@ const OxiIcons = {
         576,
         'M566.6 54.6c12.5-12.5 12.5-32.8 0-45.3s-32.8-12.5-45.3 0l-192 192-34.7-34.7c-4.2-4.2-10-6.6-16-6.6c-12.5 0-22.6 10.1-22.6 22.6l0 29.1L364.3 320l29.1 0c12.5 0 22.6-10.1 22.6-22.6c0-6-2.4-11.8-6.6-16l-34.7-34.7 192-192zM341.1 353.4L222.6 234.9c-42.7-3.7-85.2 11.7-115.8 42.3l-8 8C76.5 307.5 64 337.7 64 369.2c0 6.8 7.1 11.2 13.2 8.2l51.1-25.5c5-2.5 9.5 4.1 5.4 7.9L7.3 473.4C2.7 477.6 0 483.6 0 489.9C0 502.1 9.9 512 22.1 512l173.3 0c38.8 0 75.9-15.4 103.4-42.8c30.6-30.6 45.9-73.1 42.3-115.8z'
     ],
+    'building-circle-check': [
+        576,
+        'M96 0C60.7 0 32 28.7 32 64l0 384c0 35.3 28.7 64 64 64l180 0c-10.5-14.6-19-30.7-25.1-48l-74.9 0 0-80c0-17.7 14.3-32 32-32l32 0c2 0 4 .2 5.9 .5 6-23.6 16.3-45.4 30.1-64.5l-4 0c-8.8 0-16-7.2-16-16l0-32c0-8.8 7.2-16 16-16l32 0c8.8 0 16 7.2 16 16l0 4c27.5-19.8 60.3-32.4 96-35.4L416 64c0-35.3-28.7-64-64-64L96 0zm32 112c0-8.8 7.2-16 16-16l32 0c8.8 0 16 7.2 16 16l0 32c0 8.8-7.2 16-16 16l-32 0c-8.8 0-16-7.2-16-16l0-32zM272 96l32 0c8.8 0 16 7.2 16 16l0 32c0 8.8-7.2 16-16 16l-32 0c-8.8 0-16-7.2-16-16l0-32c0-8.8 7.2-16 16-16zM128 240c0-8.8 7.2-16 16-16l32 0c8.8 0 16 7.2 16 16l0 32c0 8.8-7.2 16-16 16l-32 0c-8.8 0-16-7.2-16-16l0-32zM576 400a144 144 0 1 0 -288 0 144 144 0 1 0 288 0zm-86.6-60.9c7.1 5.2 8.7 15.2 3.5 22.3l-64 88c-2.8 3.8-7 6.2-11.7 6.5s-9.3-1.3-12.6-4.6l-40-40c-6.2-6.2-6.2-16.4 0-22.6s16.4-6.2 22.6 0l26.8 26.8 53-72.9c5.2-7.1 15.2-8.7 22.4-3.5z'
+    ],
+    'building-circle-xmark': [
+        576,
+        'M96 0C60.7 0 32 28.7 32 64l0 384c0 35.3 28.7 64 64 64l180 0c-10.5-14.6-19-30.7-25.1-48l-74.9 0 0-80c0-17.7 14.3-32 32-32l32 0c2 0 4 .2 5.9 .5 6-23.6 16.3-45.4 30.1-64.5l-4 0c-8.8 0-16-7.2-16-16l0-32c0-8.8 7.2-16 16-16l32 0c8.8 0 16 7.2 16 16l0 4c27.5-19.8 60.3-32.4 96-35.4L416 64c0-35.3-28.7-64-64-64L96 0zm32 112c0-8.8 7.2-16 16-16l32 0c8.8 0 16 7.2 16 16l0 32c0 8.8-7.2 16-16 16l-32 0c-8.8 0-16-7.2-16-16l0-32zM272 96l32 0c8.8 0 16 7.2 16 16l0 32c0 8.8-7.2 16-16 16l-32 0c-8.8 0-16-7.2-16-16l0-32c0-8.8 7.2-16 16-16zM128 240c0-8.8 7.2-16 16-16l32 0c8.8 0 16 7.2 16 16l0 32c0 8.8-7.2 16-16 16l-32 0c-8.8 0-16-7.2-16-16l0-32zM432 544a144 144 0 1 0 0-288 144 144 0 1 0 0 288zm22.6-144l36.7 36.7c6.2 6.2 6.2 16.4 0 22.6s-16.4 6.2-22.6 0l-36.7-36.7-36.7 36.7c-6.2 6.2-16.4 6.2-22.6 0s-6.2-16.4 0-22.6l36.7-36.7-36.7-36.7c-6.2-6.2-6.2-16.4 0-22.6s16.4-6.2 22.6 0l36.7 36.7 36.7-36.7c6.2-6.2 16.4-6.2 22.6 0s6.2 16.4 0 22.6L454.6 400z'
+    ],
     calendar: [
         512,
         'M120 0c13.3 0 24 10.7 24 24l0 40 160 0 0-40c0-13.3 10.7-24 24-24s24 10.7 24 24l0 40 32 0c35.3 0 64 28.7 64 64l0 288c0 35.3-28.7 64-64 64L64 480c-35.3 0-64-28.7-64-64L0 128C0 92.7 28.7 64 64 64l32 0 0-40c0-13.3 10.7-24 24-24zm0 112l-56 0c-8.8 0-16 7.2-16 16l0 48 352 0 0-48c0-8.8-7.2-16-16-16l-264 0zM48 224l0 192c0 8.8 7.2 16 16 16l320 0c8.8 0 16-7.2 16-16l0-192-352 0z'
diff --git a/static/js/core/types.js b/static/js/core/types.js
index 3eff214b..ef006901 100644
--- a/static/js/core/types.js
+++ b/static/js/core/types.js
@@ -141,6 +141,12 @@
  */
 
 /**
+ * Wire shape of `UserDto` (backend: `src/application/dtos/user_dto.rs`).
+ * Returned by `/api/auth/me`, `/api/users/{id}`, the login response, and
+ * the admin user-management endpoints. Optional fields (`image`,
+ * `given_name`, `family_name`) are omitted when null on the wire — the
+ * `?` markers below reflect that.
+ *
  * @typedef {Object} User
  * @property {string} id
  * @property {string} username
@@ -148,11 +154,16 @@
  * @property {string} role
  * @property {number} storage_quota_bytes
  * @property {number} storage_used_bytes
- * @property {number} created_at
- * @property {number} updated_at
- * @property {number} last_login_at
+ * @property {string} created_at  ISO 8601 timestamp
+ * @property {string} updated_at  ISO 8601 timestamp
+ * @property {string|null} [last_login_at]  ISO 8601 timestamp; null until first login
  * @property {boolean} active
- * @property {string}  auth_provider
+ * @property {string}  auth_provider  "local" or OIDC provider id
+ * @property {string|null} [image]    Avatar URL or data URI
+ * @property {boolean} can_edit_image  False for OIDC-only users
+ * @property {boolean} is_external    True for magic-link / OIDC-only / OCM recipients
+ * @property {string} [given_name]    OIDC `given_name` claim, when set
+ * @property {string} [family_name]   OIDC `family_name` claim, when set
  */
 
 /**
@@ -447,6 +458,12 @@
  * @property {string|null}  [expires_at]  - YYYY-MM-DD expiry date string, or null for no expiry.
  * @property {string}       [_displayName] - Optional human-readable label (set for group subjects so the row can show the group name; user subjects resolve their name via `createUserVignette`).
  * @property {boolean}      [_isVirtual]  - True when this row's subject is a virtual (system-managed) group, so the vignette renders with the virtual-group icon.
+ * @property {string}       [_invitedEmail] - Transient marker for an
+ *   email-invite that hasn't been committed yet. When set, the row
+ *   renders with `pendingEmailVignette` (no UUID known) and
+ *   `_applyAll` POSTs `subject.type=email` to `/api/grants`. Cleared
+ *   on the next `fetchOutgoingGrants` refresh once the server has
+ *   resolved the recipient to a real user UUID.
  */
 
 /**
diff --git a/static/js/model/systemUsers.js b/static/js/model/systemUsers.js
index 7e9360ce..f7f040b3 100644
--- a/static/js/model/systemUsers.js
+++ b/static/js/model/systemUsers.js
@@ -15,7 +15,7 @@
  * returns false and `getDisplayName()` returns a shortened UUID.
  */
 
-/** @import {ContactItem} from '../core/types.js' */
+/** @import {ContactItem, User} from '../core/types.js' */
 
 import { addressBook, SYSTEM_BOOK_ID } from './addressBook.js';
 
@@ -28,6 +28,16 @@ let _photoIndex = null;
 /** @type {Map<string, string | null> | null} userId → primary email (or null), built lazily */
 let _emailIndex = null;
 
+/** @type {Map<string, boolean> | null} userId → is_external flag, built lazily.
+ *  The system-book bulk load populates `false` for every entry (PR 6 filters
+ *  externals out of the system book). Externals appear only when their UUID
+ *  shows up in a grant — `_resolveMissing` then back-fills via `/api/users/{id}`.
+ */
+let _externalIndex = null;
+
+/** @type {Map<string, Promise<void>>} userId → in-flight fetch (de-dupe). */
+const _inflight = new Map();
+
 /**
  * Derive the best human-readable name from a contact.
  * Priority: "First Last" → full_name → primary email → shortened id.
@@ -61,12 +71,16 @@ async function _ensureIndex() {
             return [c.id, primary];
         })
     );
+    // System book is internal-only post-PR-6 → every entry here is is_external=false.
+    _externalIndex = new Map(contacts.map((c) => [c.id, false]));
 
     // Inject the current user if they are not already in the index
     try {
         const raw = localStorage.getItem('oxicloud_user');
         if (raw) {
-            const u = /** @type {{id?:string, display_name?:string, username?:string, email?:string, image?:string|null}} */ (JSON.parse(raw));
+            const u = /** @type {{id?:string, display_name?:string, username?:string, email?:string, image?:string|null, is_external?:boolean}} */ (
+                JSON.parse(raw)
+            );
             if (u?.id) {
                 if (!_index.has(u.id)) {
                     const name = u.display_name || u.username || u.email || `${u.id.slice(0, 8)}…`;
@@ -78,6 +92,9 @@ async function _ensureIndex() {
                 if (!_emailIndex.has(u.id)) {
                     _emailIndex.set(u.id, u.email ?? null);
                 }
+                if (!_externalIndex.has(u.id)) {
+                    _externalIndex.set(u.id, u.is_external ?? false);
+                }
             }
         }
     } catch {
@@ -85,6 +102,46 @@ async function _ensureIndex() {
     }
 }
 
+/**
+ * Fetch a single user profile from `/api/users/{id}` and back-fill every
+ * cache map. Used when a userId surfaces (e.g. via a grant) that wasn't
+ * part of the bulk system-book load — typically external users.
+ *
+ * In-flight requests are de-duplicated through `_inflight` so concurrent
+ * vignette renders for the same external userId issue only one HTTP call.
+ * Failures (404 / 403 / 429 / network) leave the caches in their
+ * default-unknown state; callers fall back to UUID-prefix display.
+ *
+ * @param {string} userId
+ * @returns {Promise<void>}
+ */
+async function _resolveMissing(userId) {
+    if (_index?.has(userId)) return;
+    const pending = _inflight.get(userId);
+    if (pending) return pending;
+
+    const promise = (async () => {
+        try {
+            const resp = await fetch(`/api/users/${encodeURIComponent(userId)}`, {
+                credentials: 'same-origin'
+            });
+            if (!resp.ok) return;
+            /** @type {User} */
+            const u = await resp.json();
+            _index?.set(u.id, u.username || u.email || `${u.id.slice(0, 8)}…`);
+            _photoIndex?.set(u.id, u.image ?? null);
+            _emailIndex?.set(u.id, u.email ?? null);
+            _externalIndex?.set(u.id, !!u.is_external);
+        } catch {
+            // network error — caches stay unset; getters fall back to defaults
+        } finally {
+            _inflight.delete(userId);
+        }
+    })();
+    _inflight.set(userId, promise);
+    return promise;
+}
+
 // ── Public API ────────────────────────────────────────────────────────────────
 
 /**
@@ -111,13 +168,17 @@ function getDisplayNameSync(userId) {
 
 /**
  * Resolve a user UUID to a display name.
- * Awaits the first load if not yet cached; subsequent calls resolve instantly.
+ * Awaits the first load if not yet cached; subsequent calls resolve
+ * instantly. On a system-book miss (e.g. external users, which are
+ * filtered out of the system address book), back-fills via
+ * `/api/users/{id}` once per session.
  *
  * @param {string} userId
  * @returns {Promise<string>}
  */
 async function getDisplayName(userId) {
     await _ensureIndex();
+    if (!_index?.has(userId)) await _resolveMissing(userId);
     return _index?.get(userId) ?? `${userId.slice(0, 8)}…`;
 }
 
@@ -130,6 +191,7 @@ async function getDisplayName(userId) {
  */
 async function getPhoto(userId) {
     await _ensureIndex();
+    if (!_index?.has(userId)) await _resolveMissing(userId);
     return _photoIndex?.get(userId) ?? null;
 }
 
@@ -142,9 +204,26 @@ async function getPhoto(userId) {
  */
 async function getEmail(userId) {
     await _ensureIndex();
+    if (!_index?.has(userId)) await _resolveMissing(userId);
     return _emailIndex?.get(userId) ?? null;
 }
 
+/**
+ * Resolve a user UUID to whether they are an external (grant-only)
+ * recipient. Defaults to `false` (internal-by-assumption) for unknown
+ * UUIDs so callers can render without an extra null-check.
+ * Awaits the first system-book load; falls back to `/api/users/{id}`
+ * on miss — externals are excluded from the system book per PR 6.
+ *
+ * @param {string} userId
+ * @returns {Promise<boolean>}
+ */
+async function getIsExternal(userId) {
+    await _ensureIndex();
+    if (!_externalIndex?.has(userId)) await _resolveMissing(userId);
+    return _externalIndex?.get(userId) ?? false;
+}
+
 /**
  * Force-refresh the current user's photo entry in the index from localStorage.
  * Call this after saving a new avatar on the profile page so that existing
@@ -172,4 +251,13 @@ function isAvailable() {
     return addressBook.isSystemAvailable();
 }
 
-export const systemUsers = { prefetch, getDisplayName, getDisplayNameSync, getPhoto, getEmail, refreshCurrentUserPhoto, isAvailable };
+export const systemUsers = {
+    prefetch,
+    getDisplayName,
+    getDisplayNameSync,
+    getPhoto,
+    getEmail,
+    getIsExternal,
+    refreshCurrentUserPhoto,
+    isAvailable
+};
diff --git a/static/locales/en.json b/static/locales/en.json
index 38eec795..cc4dda02 100644
--- a/static/locales/en.json
+++ b/static/locales/en.json
@@ -157,7 +157,8 @@
         "shareCopied": "Link copied to clipboard",
         "shareCreated": "Share link created successfully",
         "shareUpdated": "Share settings updated successfully",
-        "shareRemoved": "Share removed successfully"
+        "shareRemoved": "Share removed successfully",
+        "inviteByEmail": "Invite by email — invitation will be sent"
     },
     "share_dialogTitle": "Share Link",
     "share_linkLabel": "Share Link:",
diff --git a/static/locales/fr.json b/static/locales/fr.json
index 1d96c7c1..1433798a 100644
--- a/static/locales/fr.json
+++ b/static/locales/fr.json
@@ -157,7 +157,8 @@
         "shareCopied": "Lien copié dans le presse-papiers",
         "shareCreated": "Lien de partage créé avec succès",
         "shareUpdated": "Paramètres de partage mis à jour",
-        "shareRemoved": "Partage supprimé avec succès"
+        "shareRemoved": "Partage supprimé avec succès",
+        "inviteByEmail": "Inviter par e-mail — une invitation sera envoyée"
     },
     "share_dialogTitle": "Lien de partage",
     "share_linkLabel": "Lien partagé :",