diff --git a/src/components/layout/MainContent.tsx b/src/components/layout/MainContent.tsx
index 6bf4c32..c3b5d32 100644
--- a/src/components/layout/MainContent.tsx
+++ b/src/components/layout/MainContent.tsx
@@ -56,6 +56,11 @@ const LocalAiPage = lazyFeature(
   () => import('@/features/ai/LocalAiPage'),
   (m) => m.LocalAiPage,
 );
+// inbuxa: Management › Compliance › Audit Log (audit-hold-lock spec, AU-9).
+const AuditLogPage = lazyFeature(
+  () => import('@/features/audit/AuditLogPage'),
+  (m) => m.AuditLogPage,
+);
 const TenantLegacyProtocols = lazyFeature(
   () => import('@/features/hardening/TenantLegacyProtocols'),
   (m) => m.TenantLegacyProtocols,
@@ -120,6 +125,9 @@ function renderView(schema: Schema | null, viewName?: string, id?: string, secti
     if (componentName === 'LocalAi') {
       return <LocalAiPage />;
     }
+    if (componentName === 'AuditLog') {
+      return <AuditLogPage />;
+    }
     return (
       <div className="rounded-lg border border-dashed p-12 text-center text-muted-foreground">
         Unknown component: {componentName}
diff --git a/src/features/audit/AuditLogPage.tsx b/src/features/audit/AuditLogPage.tsx
new file mode 100644
index 0000000..fecd07b
--- /dev/null
+++ b/src/features/audit/AuditLogPage.tsx
@@ -0,0 +1,737 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+/**
+ * INBUXA: Management › Compliance › Audit Log (audit-hold-lock spec, AU-9 to
+ * AU-11). Who changed what, who signed in as an administrator, and who
+ * reached another account's data; filtered, paged newest first, exported as
+ * a file the server builds, and checked against tampering.
+ *
+ * Records can't be edited or deleted from here or anywhere else: that is the
+ * point of them. A tenant administrator sees its own tenant's records; the
+ * server decides that, not this page.
+ */
+
+import { useCallback, useEffect, useMemo, useState } from 'react';
+import { useTranslation } from 'react-i18next';
+import { ChevronLeft, ChevronRight, Download, Loader2, RotateCcw, Search, ShieldCheck } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import { Input } from '@/components/ui/input';
+import { Badge } from '@/components/ui/badge';
+import { Textarea } from '@/components/ui/textarea';
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from '@/components/ui/dialog';
+import { PageHeader } from '@/components/common/PageHeader';
+import { LoadingFallback } from '@/components/common/LoadingFallback';
+import { useAccountStore } from '@/stores/accountStore';
+import { toast } from '@/hooks/use-toast';
+import { cn } from '@/lib/utils';
+import {
+  AUDIT_ACTIONS,
+  AuditUnavailable,
+  EMPTY_FILTER,
+  PAGE_SIZE,
+  exportEvents,
+  fetchKeepForDays,
+  queryEvents,
+  updateKeepForDays,
+  verifyChains,
+  type AuditAction,
+  type AuditChange,
+  type AuditEvent,
+  type AuditFilterInput,
+  type AuditOutcome,
+  type Verification,
+} from './auditLog';
+import { formatValue, targetKindLabel, targetName } from './format';
+import { actionLabel, viaLabel } from './labels';
+
+/** What was last loaded, and for which filter and page. */
+type Load =
+  | { kind: 'loading' }
+  | { kind: 'ready'; key: string; events: AuditEvent[]; total: number }
+  | { kind: 'error'; key: string; message: string };
+
+const ANY = '__any__';
+
+export function AuditLogPage() {
+  const { t } = useTranslation();
+  const canExport = useAccountStore((s) => s.hasPermission('sysAuditExport'));
+  // Retention and verification are the server's: tenant administrators hold neither
+  const canManage = useAccountStore((s) => s.hasPermission('sysAuditSettingsUpdate'));
+
+  const [draft, setDraft] = useState<AuditFilterInput>(EMPTY_FILTER);
+  const [filter, setFilter] = useState<AuditFilterInput>(EMPTY_FILTER);
+  const [position, setPosition] = useState(0);
+  // Bumped to fetch again: Show, Clear, and after this page's own actions,
+  // which are recorded too
+  const [fetches, setFetches] = useState(0);
+  const refetch = useCallback(() => setFetches((n) => n + 1), []);
+  const [load, setLoad] = useState<Load>({ kind: 'loading' });
+  const [selected, setSelected] = useState<AuditEvent | null>(null);
+  const [exporting, setExporting] = useState(false);
+  const [verification, setVerification] = useState<Verification | null>(null);
+  const [verifying, setVerifying] = useState(false);
+  const [keepForDays, setKeepForDays] = useState<number | null>(null);
+  const [editingRetention, setEditingRetention] = useState(false);
+
+  // A page that belongs to another filter or position shows as loading
+  const key = JSON.stringify([filter, position, fetches]);
+  const shown: Load = load.kind !== 'loading' && load.key === key ? load : { kind: 'loading' };
+
+  useEffect(() => {
+    const controller = new AbortController();
+    queryEvents(filter, position, controller.signal)
+      .then((page) => {
+        if (!controller.signal.aborted) setLoad({ kind: 'ready', key, events: page.events, total: page.total });
+      })
+      .catch((e: unknown) => {
+        if (controller.signal.aborted) return;
+        setLoad({
+          kind: 'error',
+          key,
+          message:
+            e instanceof AuditUnavailable
+              ? t('audit.unavailable', 'This server does not keep an audit log.')
+              : e instanceof Error
+                ? e.message
+                : String(e),
+        });
+      });
+    return () => controller.abort();
+  }, [filter, position, key, t]);
+
+  useEffect(() => {
+    fetchKeepForDays()
+      .then(setKeepForDays)
+      .catch(() => setKeepForDays(null));
+  }, []);
+
+  const apply = useCallback(() => {
+    setPosition(0);
+    setFilter(draft);
+    refetch();
+  }, [draft, refetch]);
+
+  const clear = useCallback(() => {
+    setDraft(EMPTY_FILTER);
+    setPosition(0);
+    setFilter(EMPTY_FILTER);
+    refetch();
+  }, [refetch]);
+
+  const verify = useCallback(async () => {
+    setVerifying(true);
+    try {
+      setVerification(await verifyChains());
+      refetch();
+    } catch (e) {
+      toast({
+        variant: 'destructive',
+        title: t('audit.verifyFailed', 'The check could not run'),
+        description: e instanceof Error ? e.message : String(e),
+      });
+    } finally {
+      setVerifying(false);
+    }
+  }, [refetch, t]);
+
+  const filtered = useMemo(() => JSON.stringify(filter) !== JSON.stringify(EMPTY_FILTER), [filter]);
+
+  return (
+    <div className="mx-auto max-w-6xl space-y-5">
+      <PageHeader
+        icon="shield-check"
+        title={t('audit.title', 'Audit log')}
+        subtitle={
+          <>
+            {t(
+              'audit.subtitle',
+              'Every change administrators and the server made, administrator sign-ins, and access to other accounts. Records can’t be edited or deleted.',
+            )}{' '}
+            {keepForDays !== null && (
+              <span>
+                {t('audit.keptFor', 'Kept for {{days}} days.', { days: keepForDays })}{' '}
+                {canManage && (
+                  <button type="button" className="underline" onClick={() => setEditingRetention(true)}>
+                    {t('audit.change', 'Change')}
+                  </button>
+                )}
+              </span>
+            )}
+          </>
+        }
+        actions={
+          <>
+            {canManage && (
+              <Button variant="outline" onClick={() => void verify()} disabled={verifying}>
+                {verifying ? (
+                  <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+                ) : (
+                  <ShieldCheck className="mr-2 h-4 w-4" />
+                )}
+                {t('audit.verify', 'Check for tampering')}
+              </Button>
+            )}
+            {canExport && (
+              <Button onClick={() => setExporting(true)}>
+                <Download className="mr-2 h-4 w-4" />
+                {t('audit.export', 'Export…')}
+              </Button>
+            )}
+          </>
+        }
+      />
+
+      <Filters draft={draft} setDraft={setDraft} onApply={apply} onClear={clear} />
+
+      {shown.kind === 'loading' && <LoadingFallback />}
+      {shown.kind === 'error' && (
+        <div className="rounded-lg border border-dashed p-12 text-center text-muted-foreground">{shown.message}</div>
+      )}
+      {shown.kind === 'ready' && (
+        <>
+          <EventTable events={shown.events} onSelect={setSelected} filtered={filtered} />
+          <Pager
+            position={position}
+            count={shown.events.length}
+            total={shown.total}
+            onPrevious={() => setPosition(Math.max(0, position - PAGE_SIZE))}
+            onNext={() => setPosition(position + PAGE_SIZE)}
+          />
+        </>
+      )}
+
+      <EventDetail event={selected} onClose={() => setSelected(null)} />
+      {exporting && (
+        <ExportDialog
+          filter={filter}
+          onClose={() => {
+            setExporting(false);
+            refetch();
+          }}
+        />
+      )}
+      <VerificationDialog result={verification} onClose={() => setVerification(null)} />
+      {editingRetention && keepForDays !== null && (
+        <RetentionDialog
+          days={keepForDays}
+          onClose={() => setEditingRetention(false)}
+          onSaved={(days) => {
+            setKeepForDays(days);
+            setEditingRetention(false);
+            refetch();
+          }}
+        />
+      )}
+    </div>
+  );
+}
+
+function OutcomeBadge({ outcome }: { outcome: AuditOutcome }) {
+  const { t } = useTranslation();
+  switch (outcome.status) {
+    case 'success':
+      return <Badge variant="secondary">{t('audit.outcome.success', 'Done')}</Badge>;
+    case 'refused':
+      return (
+        <Badge variant="destructive" title={outcome.description ?? outcome.error}>
+          {t('audit.outcome.refused', 'Refused')}
+        </Badge>
+      );
+    case 'pending':
+      return (
+        <Badge variant="outline" title={t('audit.outcome.pendingHint', 'The server stopped before it finished.')}>
+          {t('audit.outcome.pending', 'Unfinished')}
+        </Badge>
+      );
+  }
+}
+
+function Filters({
+  draft,
+  setDraft,
+  onApply,
+  onClear,
+}: {
+  draft: AuditFilterInput;
+  setDraft: (f: AuditFilterInput) => void;
+  onApply: () => void;
+  onClear: () => void;
+}) {
+  const { t } = useTranslation();
+  const set = <K extends keyof AuditFilterInput>(key: K, value: AuditFilterInput[K]) =>
+    setDraft({ ...draft, [key]: value });
+  return (
+    <form
+      className="grid gap-3 rounded-xl border bg-card p-4 sm:grid-cols-2 lg:grid-cols-6"
+      onSubmit={(e) => {
+        e.preventDefault();
+        onApply();
+      }}
+    >
+      <label className="space-y-1 text-sm lg:col-span-2">
+        <span className="text-muted-foreground">{t('audit.filter.text', 'Search')}</span>
+        <Input
+          value={draft.text}
+          placeholder={t('audit.filter.textHint', 'Name, address, object, reason…')}
+          onChange={(e) => set('text', e.target.value)}
+        />
+      </label>
+      <label className="space-y-1 text-sm">
+        <span className="text-muted-foreground">{t('audit.filter.from', 'From')}</span>
+        <Input type="date" value={draft.from} onChange={(e) => set('from', e.target.value)} />
+      </label>
+      <label className="space-y-1 text-sm">
+        <span className="text-muted-foreground">{t('audit.filter.to', 'To')}</span>
+        <Input type="date" value={draft.to} onChange={(e) => set('to', e.target.value)} />
+      </label>
+      <label className="space-y-1 text-sm">
+        <span className="text-muted-foreground">{t('audit.filter.action', 'What happened')}</span>
+        <Select value={draft.action || ANY} onValueChange={(v) => set('action', v === ANY ? '' : (v as AuditAction))}>
+          <SelectTrigger>
+            <SelectValue />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem value={ANY}>{t('audit.filter.any', 'Anything')}</SelectItem>
+            {AUDIT_ACTIONS.map((a) => (
+              <SelectItem key={a} value={a}>
+                {actionLabel(t, a)}
+              </SelectItem>
+            ))}
+          </SelectContent>
+        </Select>
+      </label>
+      <label className="space-y-1 text-sm">
+        <span className="text-muted-foreground">{t('audit.filter.outcome', 'Outcome')}</span>
+        <Select
+          value={draft.outcome || ANY}
+          onValueChange={(v) => set('outcome', v === ANY ? '' : (v as AuditFilterInput['outcome']))}
+        >
+          <SelectTrigger>
+            <SelectValue />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem value={ANY}>{t('audit.filter.any', 'Anything')}</SelectItem>
+            <SelectItem value="success">{t('audit.outcome.success', 'Done')}</SelectItem>
+            <SelectItem value="refused">{t('audit.outcome.refused', 'Refused')}</SelectItem>
+            <SelectItem value="pending">{t('audit.outcome.pending', 'Unfinished')}</SelectItem>
+          </SelectContent>
+        </Select>
+      </label>
+      <div className="flex items-end gap-2 sm:col-span-2 lg:col-span-6">
+        <Button type="submit" size="sm">
+          <Search className="mr-2 h-4 w-4" />
+          {t('audit.filter.apply', 'Show')}
+        </Button>
+        <Button type="button" size="sm" variant="ghost" onClick={onClear}>
+          <RotateCcw className="mr-2 h-4 w-4" />
+          {t('audit.filter.clear', 'Clear')}
+        </Button>
+      </div>
+    </form>
+  );
+}
+
+function EventTable({
+  events,
+  onSelect,
+  filtered,
+}: {
+  events: AuditEvent[];
+  onSelect: (e: AuditEvent) => void;
+  filtered: boolean;
+}) {
+  const { t } = useTranslation();
+  if (events.length === 0) {
+    return (
+      <div className="rounded-lg border border-dashed p-12 text-center text-muted-foreground">
+        {filtered
+          ? t('audit.noneMatching', 'No records match these filters.')
+          : t('audit.none', 'Nothing has been recorded yet.')}
+      </div>
+    );
+  }
+  return (
+    <div className="overflow-x-auto rounded-xl border">
+      <table className="w-full text-sm">
+        <thead className="bg-muted/50 text-left text-muted-foreground">
+          <tr>
+            <th className="px-4 py-2 font-medium">{t('audit.col.when', 'When')}</th>
+            <th className="px-4 py-2 font-medium">{t('audit.col.who', 'Who')}</th>
+            <th className="px-4 py-2 font-medium">{t('audit.col.what', 'What')}</th>
+            <th className="px-4 py-2 font-medium">{t('audit.col.target', 'To')}</th>
+            <th className="px-4 py-2 font-medium">{t('audit.col.outcome', 'Outcome')}</th>
+          </tr>
+        </thead>
+        <tbody>
+          {events.map((event) => (
+            <tr
+              key={event.id}
+              className="cursor-pointer border-t hover:bg-muted/40"
+              onClick={() => onSelect(event)}
+              tabIndex={0}
+              onKeyDown={(e) => {
+                if (e.key === 'Enter') onSelect(event);
+              }}
+            >
+              <td className="whitespace-nowrap px-4 py-2 tabular-nums text-muted-foreground">
+                {new Date(event.at).toLocaleString()}
+              </td>
+              <td className="px-4 py-2">
+                <div className={cn(event.actor.accountId ? 'font-medium' : 'italic text-muted-foreground')}>
+                  {event.actor.name}
+                </div>
+                {event.via && <div className="text-xs text-muted-foreground">{viaLabel(t, event.via)}</div>}
+              </td>
+              <td className="px-4 py-2">{actionLabel(t, event.action)}</td>
+              <td className="px-4 py-2">
+                <span className="text-muted-foreground">{targetKindLabel(event.target.kind)}</span>{' '}
+                {targetName(event.target)}
+              </td>
+              <td className="px-4 py-2">
+                <OutcomeBadge outcome={event.outcome} />
+              </td>
+            </tr>
+          ))}
+        </tbody>
+      </table>
+    </div>
+  );
+}
+
+function Pager({
+  position,
+  count,
+  total,
+  onPrevious,
+  onNext,
+}: {
+  position: number;
+  count: number;
+  total: number;
+  onPrevious: () => void;
+  onNext: () => void;
+}) {
+  const { t } = useTranslation();
+  if (total === 0) return null;
+  return (
+    <div className="flex items-center justify-between text-sm text-muted-foreground">
+      <span>
+        {t('audit.showing', 'Showing {{from}}–{{to}} of {{total}}', {
+          from: position + 1,
+          to: position + count,
+          total,
+        })}
+      </span>
+      <div className="flex gap-2">
+        <Button size="sm" variant="outline" disabled={position === 0} onClick={onPrevious}>
+          <ChevronLeft className="h-4 w-4" />
+          {t('audit.previous', 'Newer')}
+        </Button>
+        <Button size="sm" variant="outline" disabled={position + count >= total} onClick={onNext}>
+          {t('audit.next', 'Older')}
+          <ChevronRight className="h-4 w-4" />
+        </Button>
+      </div>
+    </div>
+  );
+}
+
+function EventDetail({ event, onClose }: { event: AuditEvent | null; onClose: () => void }) {
+  const { t } = useTranslation();
+  return (
+    <Dialog open={!!event} onOpenChange={(open) => !open && onClose()}>
+      <DialogContent className="max-w-2xl">
+        {event && (
+          <>
+            <DialogHeader>
+              <DialogTitle>
+                {actionLabel(t, event.action)} · {targetKindLabel(event.target.kind)}{' '}
+                {targetName(event.target)}
+              </DialogTitle>
+              <DialogDescription>{new Date(event.at).toLocaleString()}</DialogDescription>
+            </DialogHeader>
+            <dl className="grid grid-cols-[max-content_1fr] gap-x-4 gap-y-1.5 text-sm">
+              <dt className="text-muted-foreground">{t('audit.detail.who', 'Who')}</dt>
+              <dd>
+                {event.actor.name}
+                {event.via && <span className="text-muted-foreground"> · {viaLabel(t, event.via)}</span>}
+              </dd>
+              {event.remoteIp && (
+                <>
+                  <dt className="text-muted-foreground">{t('audit.detail.from', 'From')}</dt>
+                  <dd className="font-mono">{event.remoteIp}</dd>
+                </>
+              )}
+              <dt className="text-muted-foreground">{t('audit.detail.outcome', 'Outcome')}</dt>
+              <dd className="flex items-center gap-2">
+                <OutcomeBadge outcome={event.outcome} />
+                {event.outcome.status === 'refused' && (
+                  <span className="text-muted-foreground">
+                    {event.outcome.description ?? event.outcome.error}
+                  </span>
+                )}
+              </dd>
+              {event.reason && (
+                <>
+                  <dt className="text-muted-foreground">{t('audit.detail.reason', 'Reason given')}</dt>
+                  <dd>{event.reason}</dd>
+                </>
+              )}
+              {event.details && (
+                <>
+                  <dt className="text-muted-foreground">{t('audit.detail.details', 'Details')}</dt>
+                  <dd className="break-words">{event.details}</dd>
+                </>
+              )}
+              <dt className="text-muted-foreground">{t('audit.detail.record', 'Record')}</dt>
+              <dd className="font-mono text-xs text-muted-foreground">
+                {event.id} · {t('audit.detail.node', 'node {{node}}', { node: event.node })}
+              </dd>
+            </dl>
+            {event.changes.length > 0 && <ChangeTable changes={event.changes} />}
+          </>
+        )}
+      </DialogContent>
+    </Dialog>
+  );
+}
+
+function ChangeTable({ changes }: { changes: AuditChange[] }) {
+  const { t } = useTranslation();
+  return (
+    <div className="max-h-80 overflow-auto rounded-lg border">
+      <table className="w-full text-sm">
+        <thead className="sticky top-0 bg-muted text-left text-muted-foreground">
+          <tr>
+            <th className="px-3 py-1.5 font-medium">{t('audit.change.field', 'Setting')}</th>
+            <th className="px-3 py-1.5 font-medium">{t('audit.change.before', 'Before')}</th>
+            <th className="px-3 py-1.5 font-medium">{t('audit.change.after', 'After')}</th>
+          </tr>
+        </thead>
+        <tbody>
+          {changes.map((change) => (
+            <tr key={change.field} className="border-t align-top">
+              <td className="px-3 py-1.5 font-mono text-xs">{change.field}</td>
+              {change.redacted ? (
+                <td colSpan={2} className="px-3 py-1.5 italic text-muted-foreground">
+                  {t('audit.change.secret', 'Changed. Secrets are never recorded.')}
+                </td>
+              ) : (
+                <>
+                  <td className="break-all px-3 py-1.5 font-mono text-xs text-muted-foreground">
+                    {formatValue(change.before)}
+                  </td>
+                  <td className="break-all px-3 py-1.5 font-mono text-xs">{formatValue(change.after)}</td>
+                </>
+              )}
+            </tr>
+          ))}
+        </tbody>
+      </table>
+    </div>
+  );
+}
+
+function ExportDialog({ filter, onClose }: { filter: AuditFilterInput; onClose: () => void }) {
+  const { t } = useTranslation();
+  const [format, setFormat] = useState<'csv' | 'jsonl'>('csv');
+  const [reason, setReason] = useState('');
+  const [busy, setBusy] = useState(false);
+
+  const run = async () => {
+    setBusy(true);
+    try {
+      const result = await exportEvents(filter, format, reason);
+      toast({
+        title: t('audit.exported', 'Exported {{count}} records', { count: result.count }),
+        description: (
+          <span className="break-all font-mono text-xs">
+            {t('audit.exportedHash', 'SHA-256 {{hash}}', { hash: result.sha256 })}
+          </span>
+        ),
+      });
+      onClose();
+    } catch (e) {
+      toast({
+        variant: 'destructive',
+        title: t('audit.exportFailed', 'Nothing was exported'),
+        description: e instanceof Error ? e.message : String(e),
+      });
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <Dialog open onOpenChange={(open) => !open && onClose()}>
+      <DialogContent>
+        <DialogHeader>
+          <DialogTitle>{t('audit.exportTitle', 'Export the audit log')}</DialogTitle>
+          <DialogDescription>
+            {t(
+              'audit.exportBody',
+              'The records the filters above match, up to 100,000, newest first. Each line carries its chain hash, and the file ends with a manifest, so whoever receives it can check it. The export itself is recorded.',
+            )}
+          </DialogDescription>
+        </DialogHeader>
+        <div className="space-y-3 text-sm">
+          <label className="block space-y-1">
+            <span className="text-muted-foreground">{t('audit.format', 'Format')}</span>
+            <Select value={format} onValueChange={(v) => setFormat(v as 'csv' | 'jsonl')}>
+              <SelectTrigger>
+                <SelectValue />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="csv">{t('audit.formatCsv', 'CSV (spreadsheets)')}</SelectItem>
+                <SelectItem value="jsonl">{t('audit.formatJsonl', 'JSON Lines (tools, SIEM)')}</SelectItem>
+              </SelectContent>
+            </Select>
+          </label>
+          <label className="block space-y-1">
+            <span className="text-muted-foreground">{t('audit.reason', 'Reason (optional)')}</span>
+            <Textarea
+              value={reason}
+              maxLength={500}
+              placeholder={t('audit.reasonHint', 'Ticket, request or case this is for')}
+              onChange={(e) => setReason(e.target.value)}
+            />
+          </label>
+        </div>
+        <DialogFooter>
+          <Button variant="ghost" onClick={onClose} disabled={busy}>
+            {t('audit.cancel', 'Cancel')}
+          </Button>
+          <Button onClick={() => void run()} disabled={busy}>
+            {busy && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
+            {t('audit.exportGo', 'Export')}
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
+
+function VerificationDialog({ result, onClose }: { result: Verification | null; onClose: () => void }) {
+  const { t } = useTranslation();
+  return (
+    <Dialog open={!!result} onOpenChange={(open) => !open && onClose()}>
+      <DialogContent>
+        {result && (
+          <>
+            <DialogHeader>
+              <DialogTitle className={cn(!result.verified && 'text-destructive')}>
+                {result.verified
+                  ? t('audit.verified', 'No tampering found')
+                  : t('audit.broken', 'The audit log was changed')}
+              </DialogTitle>
+              <DialogDescription>
+                {result.verified
+                  ? t(
+                      'audit.verifiedBody',
+                      'Every record on every node follows from the one before it. This catches edits to the store; it can’t stop someone with root on the server rewriting everything, so forward records to a system your mail administrators don’t control as well.',
+                    )
+                  : t(
+                      'audit.brokenBody',
+                      'At least one record doesn’t follow from the one before it. Keep the server as it is and compare against an export or a forwarded copy.',
+                    )}
+              </DialogDescription>
+            </DialogHeader>
+            <ul className="space-y-2 text-sm">
+              {result.chains.map((chain) => (
+                <li key={chain.node} className="rounded-lg border p-3">
+                  <div className="font-medium">
+                    {t('audit.chainNode', 'Node {{node}}', { node: chain.node })}:{' '}
+                    {chain.brokenAt
+                      ? t('audit.chainBroken', 'broken at record {{at}}', { at: chain.brokenAt })
+                      : t('audit.chainOk', '{{count}} entries verified', { count: chain.entries })}
+                  </div>
+                  {chain.reason && <div className="text-muted-foreground">{chain.reason}</div>}
+                  {chain.unfinished > 0 && (
+                    <div className="text-muted-foreground">
+                      {t('audit.chainUnfinished', '{{count}} changes never recorded an outcome.', {
+                        count: chain.unfinished,
+                      })}
+                    </div>
+                  )}
+                </li>
+              ))}
+            </ul>
+          </>
+        )}
+      </DialogContent>
+    </Dialog>
+  );
+}
+
+function RetentionDialog({
+  days,
+  onClose,
+  onSaved,
+}: {
+  days: number;
+  onClose: () => void;
+  onSaved: (days: number) => void;
+}) {
+  const { t } = useTranslation();
+  const [value, setValue] = useState(String(days));
+  const [busy, setBusy] = useState(false);
+  const parsed = Number(value);
+  const valid = Number.isInteger(parsed) && parsed >= 90;
+
+  const save = async () => {
+    setBusy(true);
+    try {
+      await updateKeepForDays(parsed);
+      onSaved(parsed);
+    } catch (e) {
+      toast({
+        variant: 'destructive',
+        title: t('audit.retentionFailed', 'Not saved'),
+        description: e instanceof Error ? e.message : String(e),
+      });
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <Dialog open onOpenChange={(open) => !open && onClose()}>
+      <DialogContent>
+        <DialogHeader>
+          <DialogTitle>{t('audit.retentionTitle', 'How long records are kept')}</DialogTitle>
+          <DialogDescription>
+            {t(
+              'audit.retentionBody',
+              'Older records are removed once a day. At least 90 days; the default is two years. This change is recorded too.',
+            )}
+          </DialogDescription>
+        </DialogHeader>
+        <label className="block space-y-1 text-sm">
+          <span className="text-muted-foreground">{t('audit.retentionDays', 'Days')}</span>
+          <Input type="number" min={90} value={value} onChange={(e) => setValue(e.target.value)} />
+        </label>
+        <DialogFooter>
+          <Button variant="ghost" onClick={onClose} disabled={busy}>
+            {t('audit.cancel', 'Cancel')}
+          </Button>
+          <Button onClick={() => void save()} disabled={busy || !valid}>
+            {busy && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
+            {t('audit.save', 'Save')}
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
diff --git a/src/features/audit/auditLog.test.ts b/src/features/audit/auditLog.test.ts
new file mode 100644
index 0000000..05e15b7
--- /dev/null
+++ b/src/features/audit/auditLog.test.ts
@@ -0,0 +1,71 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { describe, expect, it } from 'vitest';
+import { EMPTY_FILTER, normalize, toServerFilter } from './auditLog';
+import { formatValue, targetKindLabel, targetName } from './format';
+
+describe('toServerFilter', () => {
+  it('sends nothing for an empty filter', () => {
+    expect(toServerFilter(EMPTY_FILTER)).toEqual({});
+  });
+
+  it('turns local days into a half-open UTC range covering both days', () => {
+    const filter = toServerFilter({ ...EMPTY_FILTER, from: '2026-09-01', to: '2026-09-02' });
+    const after = new Date(filter.after!);
+    const before = new Date(filter.before!);
+    expect(after.getTime()).toBe(new Date(2026, 8, 1).getTime());
+    expect(before.getTime()).toBe(new Date(2026, 8, 3).getTime());
+    expect(filter.after).toMatch(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z$/);
+  });
+
+  it('passes the other conditions through, trimmed', () => {
+    expect(
+      toServerFilter({
+        ...EMPTY_FILTER,
+        action: 'signIn',
+        outcome: 'refused',
+        targetKind: ' x:Domain ',
+        text: '  admin  ',
+      }),
+    ).toEqual({ action: 'signIn', outcome: 'refused', targetKind: 'x:Domain', text: 'admin' });
+  });
+});
+
+describe('normalize', () => {
+  it('fills what the server leaves out', () => {
+    const event = normalize({ id: 'a', action: 'signIn' });
+    expect(event.changes).toEqual([]);
+    expect(event.via).toBeNull();
+    expect(event.reason).toBeNull();
+    expect(event.outcome).toEqual({ status: 'pending' });
+  });
+});
+
+describe('format', () => {
+  it('names object kinds in words', () => {
+    expect(targetKindLabel('x:Domain')).toBe('Domain');
+    expect(targetKindLabel('x:DkimSignature')).toBe('DKIM signature');
+    expect(targetKindLabel('x:BlockedIp')).toBe('Blocked IP');
+    expect(targetKindLabel('inbuxa:AuditSettings')).toBe('Audit settings');
+    expect(targetKindLabel('x:OAuthClient')).toBe('OAuth client');
+    expect(targetKindLabel('account')).toBe('Account');
+    expect(targetKindLabel('inbuxa:AuditEvent')).toBe('Audit log');
+  });
+
+  it('never names a target by a singleton id', () => {
+    expect(targetName({ id: 'singleton' })).toBe('');
+    expect(targetName({ id: 'b', name: 'example.com' })).toBe('example.com');
+    expect(targetName({ id: 'b' })).toBe('b');
+  });
+
+  it('shows values plainly', () => {
+    expect(formatValue(undefined)).toBe('—');
+    expect(formatValue('text')).toBe('text');
+    expect(formatValue(false)).toBe('false');
+    expect(formatValue({ '@type': 'Manual' })).toBe('{"@type":"Manual"}');
+  });
+});
diff --git a/src/features/audit/auditLog.ts b/src/features/audit/auditLog.ts
new file mode 100644
index 0000000..d3b608e
--- /dev/null
+++ b/src/features/audit/auditLog.ts
@@ -0,0 +1,329 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+/**
+ * INBUXA: the audit log over JMAP (audit-hold-lock spec, AU-9 to AU-11):
+ * `inbuxa:AuditEvent`, `inbuxa:AuditSettings`, `inbuxa:AuditExport` and
+ * `inbuxa:AuditVerification`. This module is the wire; the page draws from it.
+ */
+
+import { apiFetch } from '@/services/api';
+import { fetchSession, getAccountId, jmapRequest } from '@/services/jmap/client';
+
+export const INBUXA_CAPABILITY = 'urn:inbuxa:jmap';
+export const PAGE_SIZE = 50;
+
+export type AuditAction =
+  | 'create'
+  | 'update'
+  | 'destroy'
+  | 'signIn'
+  | 'signInFailed'
+  | 'accountAccess'
+  | 'blobAccess'
+  | 'export'
+  | 'verify';
+
+export const AUDIT_ACTIONS: AuditAction[] = [
+  'create',
+  'update',
+  'destroy',
+  'signIn',
+  'signInFailed',
+  'accountAccess',
+  'blobAccess',
+  'export',
+  'verify',
+];
+
+export interface AuditActor {
+  accountId?: string;
+  name: string;
+  tenantId?: string;
+}
+
+export type AuditVia =
+  | { kind: 'password' }
+  | { kind: 'appPassword'; id: number }
+  | { kind: 'apiKey'; id: number }
+  | { kind: 'oauth'; client: string }
+  | { kind: 'directory' }
+  | { kind: 'master'; accountId?: string; name: string }
+  | { kind: 'recovery' };
+
+export interface AuditTarget {
+  kind: string;
+  id?: string;
+  name?: string;
+  accountId?: string;
+  tenantId?: string;
+}
+
+export interface AuditChange {
+  field: string;
+  before?: unknown;
+  after?: unknown;
+  redacted?: boolean;
+}
+
+export type AuditOutcome =
+  | { status: 'success'; createdId?: string }
+  | { status: 'refused'; error: string; description?: string }
+  | { status: 'pending' };
+
+export interface AuditEvent {
+  id: string;
+  /** RFC 3339, to the millisecond. */
+  at: string;
+  node: number;
+  actor: AuditActor;
+  via: AuditVia | null;
+  remoteIp: string | null;
+  action: AuditAction;
+  target: AuditTarget;
+  changes: AuditChange[];
+  details: string | null;
+  reason: string | null;
+  outcome: AuditOutcome;
+}
+
+/** What the page filters by. Empty strings mean "any". */
+export interface AuditFilterInput {
+  /** `yyyy-mm-dd`, local day, inclusive. */
+  from: string;
+  /** `yyyy-mm-dd`, local day, inclusive. */
+  to: string;
+  action: AuditAction | '';
+  outcome: 'success' | 'refused' | 'pending' | '';
+  targetKind: string;
+  text: string;
+}
+
+export const EMPTY_FILTER: AuditFilterInput = {
+  from: '',
+  to: '',
+  action: '',
+  outcome: '',
+  targetKind: '',
+  text: '',
+};
+
+/** The server's filter object: every condition must hold. */
+export function toServerFilter(input: AuditFilterInput): Record<string, string> {
+  const filter: Record<string, string> = {};
+  if (input.from) filter.after = localDayStart(input.from).toISOString().replace(/\.\d{3}Z$/, 'Z');
+  if (input.to) {
+    const end = localDayStart(input.to);
+    end.setDate(end.getDate() + 1);
+    filter.before = end.toISOString().replace(/\.\d{3}Z$/, 'Z');
+  }
+  if (input.action) filter.action = input.action;
+  if (input.outcome) filter.outcome = input.outcome;
+  if (input.targetKind.trim()) filter.targetKind = input.targetKind.trim();
+  if (input.text.trim()) filter.text = input.text.trim();
+  return filter;
+}
+
+function localDayStart(day: string): Date {
+  const [y, m, d] = day.split('-').map(Number);
+  return new Date(y, (m ?? 1) - 1, d ?? 1);
+}
+
+function methodError(name: string | undefined, result: unknown): Error {
+  const r = result as { type?: string; description?: string } | undefined;
+  if (r?.type === 'unknownMethod' || r?.type === 'unknownCapability') {
+    return new AuditUnavailable(r.type);
+  }
+  return new Error(r?.description ?? r?.type ?? `${name ?? 'Request'} failed`);
+}
+
+/** The server doesn't offer the audit log (an older server, or not inbuxa). */
+export class AuditUnavailable extends Error {
+  constructor(reason: string) {
+    super(`Audit log unavailable: ${reason}`);
+  }
+}
+
+export interface AuditPage {
+  events: AuditEvent[];
+  total: number;
+}
+
+/** One page of events, newest first. */
+export async function queryEvents(
+  input: AuditFilterInput,
+  position: number,
+  signal?: AbortSignal,
+): Promise<AuditPage> {
+  const accountId = getAccountId('x:Account');
+  const responses = await jmapRequest(
+    [
+      [
+        'inbuxa:AuditEvent/query',
+        { accountId, filter: toServerFilter(input), position, limit: PAGE_SIZE, calculateTotal: true },
+        'q',
+      ],
+      [
+        'inbuxa:AuditEvent/get',
+        { accountId, '#ids': { resultOf: 'q', name: 'inbuxa:AuditEvent/query', path: '/ids' } },
+        'g',
+      ],
+    ],
+    signal,
+    [INBUXA_CAPABILITY],
+  );
+  const [qName, qResult] = responses[0] ?? [];
+  if (qName !== 'inbuxa:AuditEvent/query') throw methodError(qName, qResult);
+  const [gName, gResult] = responses[1] ?? [];
+  if (gName !== 'inbuxa:AuditEvent/get') throw methodError(gName, gResult);
+  const ids = (qResult as { ids?: string[] }).ids ?? [];
+  const byId = new Map(((gResult as { list?: AuditEvent[] }).list ?? []).map((e) => [e.id, normalize(e)]));
+  return {
+    // Keep the query's order: newest first
+    events: ids.map((id) => byId.get(id)).filter((e): e is AuditEvent => !!e),
+    total: (qResult as { total?: number }).total ?? ids.length,
+  };
+}
+
+/** Fills what the server leaves out when it has nothing to say. */
+export function normalize(raw: Partial<AuditEvent> & { id: string }): AuditEvent {
+  return {
+    id: raw.id,
+    at: raw.at ?? '',
+    node: raw.node ?? 0,
+    actor: raw.actor ?? { name: '' },
+    via: raw.via ?? null,
+    remoteIp: raw.remoteIp ?? null,
+    action: (raw.action ?? 'update') as AuditAction,
+    target: raw.target ?? { kind: '' },
+    changes: raw.changes ?? [],
+    details: raw.details ?? null,
+    reason: raw.reason ?? null,
+    outcome: raw.outcome ?? { status: 'pending' },
+  };
+}
+
+export async function fetchKeepForDays(): Promise<number> {
+  const accountId = getAccountId('x:Account');
+  const responses = await jmapRequest(
+    [['inbuxa:AuditSettings/get', { accountId, ids: null }, '0']],
+    undefined,
+    [INBUXA_CAPABILITY],
+  );
+  const [name, result] = responses[0] ?? [];
+  if (name !== 'inbuxa:AuditSettings/get') throw methodError(name, result);
+  return (result as { list?: { keepForDays?: number }[] }).list?.[0]?.keepForDays ?? 730;
+}
+
+export async function updateKeepForDays(days: number): Promise<void> {
+  const accountId = getAccountId('x:Account');
+  const responses = await jmapRequest(
+    [['inbuxa:AuditSettings/set', { accountId, update: { singleton: { keepForDays: days } } }, '0']],
+    undefined,
+    [INBUXA_CAPABILITY],
+  );
+  const [name, result] = responses[0] ?? [];
+  if (name !== 'inbuxa:AuditSettings/set') throw methodError(name, result);
+  const failed = (result as { notUpdated?: Record<string, { description?: string; type?: string }> }).notUpdated
+    ?.singleton;
+  if (failed) throw new Error(failed.description ?? failed.type ?? 'Not saved');
+}
+
+export interface ExportResult {
+  count: number;
+  sha256: string;
+}
+
+/** Asks the server for a file of the matching records, and saves it (AU-11). */
+export async function exportEvents(
+  input: AuditFilterInput,
+  format: 'csv' | 'jsonl',
+  reason: string,
+): Promise<ExportResult> {
+  const accountId = getAccountId('x:Account');
+  const create: Record<string, unknown> = { format, filter: toServerFilter(input) };
+  if (reason.trim()) create.reason = reason.trim();
+  const responses = await jmapRequest(
+    [['inbuxa:AuditExport/set', { accountId, create: { x: create } }, '0']],
+    undefined,
+    [INBUXA_CAPABILITY],
+  );
+  const [name, result] = responses[0] ?? [];
+  if (name !== 'inbuxa:AuditExport/set') throw methodError(name, result);
+  const r = result as {
+    created?: { x?: { blobId: string; count: number; sha256: string } };
+    notCreated?: { x?: { description?: string; type?: string } };
+  };
+  const created = r.created?.x;
+  if (!created) throw new Error(r.notCreated?.x?.description ?? r.notCreated?.x?.type ?? 'Export failed');
+
+  const fileName = `audit-${new Date().toISOString().slice(0, 10)}.${format === 'csv' ? 'csv' : 'jsonl'}`;
+  const type = format === 'csv' ? 'text/csv' : 'application/jsonl';
+  const session = await fetchSession();
+  const template =
+    typeof session.downloadUrl === 'string'
+      ? session.downloadUrl
+      : '/jmap/download/{accountId}/{blobId}/{name}?accept={type}';
+  const url = template
+    .replace('{accountId}', encodeURIComponent(accountId))
+    .replace('{blobId}', encodeURIComponent(created.blobId))
+    .replace('{name}', encodeURIComponent(fileName))
+    .replace('{type}', encodeURIComponent(type));
+  const response = await apiFetch(pathOf(url));
+  if (!response.ok) throw new Error(`Download failed (${response.status})`);
+  saveBlob(await response.blob(), fileName);
+  return { count: created.count, sha256: created.sha256 };
+}
+
+function pathOf(url: string): string {
+  try {
+    const u = new URL(url, 'http://placeholder');
+    return u.pathname + u.search;
+  } catch {
+    return url;
+  }
+}
+
+function saveBlob(blob: Blob, fileName: string) {
+  const href = URL.createObjectURL(blob);
+  const a = document.createElement('a');
+  a.href = href;
+  a.download = fileName;
+  document.body.appendChild(a);
+  a.click();
+  a.remove();
+  setTimeout(() => URL.revokeObjectURL(href), 10_000);
+}
+
+export interface ChainReport {
+  node: number;
+  entries: number;
+  firstSeq: number;
+  lastSeq: number;
+  brokenAt?: string;
+  reason?: string;
+  unfinished: number;
+}
+
+export interface Verification {
+  verified: boolean;
+  chains: ChainReport[];
+}
+
+/** Rechecks every node's chain (AU-6). Server administrators only. */
+export async function verifyChains(): Promise<Verification> {
+  const accountId = getAccountId('x:Account');
+  const responses = await jmapRequest(
+    [['inbuxa:AuditVerification/set', { accountId, create: { v: {} } }, '0']],
+    undefined,
+    [INBUXA_CAPABILITY],
+  );
+  const [name, result] = responses[0] ?? [];
+  if (name !== 'inbuxa:AuditVerification/set') throw methodError(name, result);
+  const created = (result as { created?: { v?: Verification } }).created?.v;
+  if (!created) throw new Error('Verification failed');
+  return { verified: created.verified, chains: created.chains ?? [] };
+}
diff --git a/src/features/audit/format.ts b/src/features/audit/format.ts
new file mode 100644
index 0000000..455608d
--- /dev/null
+++ b/src/features/audit/format.ts
@@ -0,0 +1,61 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+/** INBUXA: how audit records read on screen (audit-hold-lock spec, AU-4). */
+
+/** Words the registry spells in camel case that read as acronyms. */
+const ACRONYMS: Record<string, string> = {
+  Oauth: 'OAuth',
+  Dkim: 'DKIM',
+  Dmarc: 'DMARC',
+  Dns: 'DNS',
+  Dnsbl: 'DNSBL',
+  Mta: 'MTA',
+  Acme: 'ACME',
+  Ip: 'IP',
+  Ai: 'AI',
+  Llm: 'LLM',
+  Tls: 'TLS',
+  Spf: 'SPF',
+  Arf: 'ARF',
+  Dsn: 'DSN',
+  Http: 'HTTP',
+  Imap: 'IMAP',
+  Jmap: 'JMAP',
+  Oidc: 'OIDC',
+  Sts: 'STS',
+  Api: 'API',
+  Scim: 'SCIM',
+};
+
+/** `x:DkimSignature` reads as "DKIM signature"; fork objects lose their prefix too. */
+export function targetKindLabel(kind: string): string {
+  if (kind === 'account') return 'Account';
+  // Exports and checks act on the log itself
+  if (kind === 'inbuxa:AuditEvent') return 'Audit log';
+  const name = kind.replace(/^(x|inbuxa):/, '').replace('OAuth', 'Oauth');
+  if (!name) return '';
+  return name
+    .replace(/([a-z0-9])([A-Z])/g, '$1 $2')
+    .split(' ')
+    .map((word, i) => ACRONYMS[word] ?? (i === 0 ? word : word.toLowerCase()))
+    .join(' ');
+}
+
+/** One side of a change: absent reads as a dash, text as itself, anything else as JSON. */
+export function formatValue(value: unknown): string {
+  if (value === undefined || value === null) return '—';
+  if (typeof value === 'string') return value;
+  if (typeof value === 'number' || typeof value === 'boolean') return String(value);
+  return JSON.stringify(value);
+}
+
+/** What a record names its target by: a singleton's id says nothing. */
+export function targetName(target: { name?: string; id?: string }): string {
+  if (target.name) return target.name;
+  if (target.id && target.id !== 'singleton') return target.id;
+  return '';
+}
diff --git a/src/features/audit/labels.ts b/src/features/audit/labels.ts
new file mode 100644
index 0000000..408cdc0
--- /dev/null
+++ b/src/features/audit/labels.ts
@@ -0,0 +1,60 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+/** INBUXA: the audit log's words for actions and sign-in methods. */
+
+import type { AuditAction, AuditVia } from './auditLog';
+
+type T = (key: string, fallback: string, options?: Record<string, unknown>) => string;
+
+export function actionLabel(t: T, action: AuditAction): string {
+  switch (action) {
+    case 'create':
+      return t('audit.action.create', 'Created');
+    case 'update':
+      return t('audit.action.update', 'Changed');
+    case 'destroy':
+      return t('audit.action.destroy', 'Deleted');
+    case 'signIn':
+      return t('audit.action.signIn', 'Signed in');
+    case 'signInFailed':
+      return t('audit.action.signInFailed', 'Sign-in failed');
+    case 'accountAccess':
+      return t('audit.action.accountAccess', 'Opened another account');
+    case 'blobAccess':
+      return t('audit.action.blobAccess', 'Read another account’s file');
+    case 'export':
+      return t('audit.action.export', 'Exported the audit log');
+    case 'verify':
+      return t('audit.action.verify', 'Checked for tampering');
+  }
+}
+
+export function viaLabel(t: T, via: AuditVia | null): string {
+  if (!via) return '';
+  switch (via.kind) {
+    case 'password':
+      return t('audit.via.password', 'password');
+    case 'appPassword':
+      return t('audit.via.appPassword', 'app password');
+    case 'apiKey':
+      return t('audit.via.apiKey', 'API key');
+    case 'oauth':
+      return t('audit.via.oauth', 'app {{client}}', { client: shortClient(via.client) });
+    case 'directory':
+      return t('audit.via.directory', 'directory token');
+    case 'master':
+      return t('audit.via.master', 'as master user {{name}}', { name: via.name });
+    case 'recovery':
+      return t('audit.via.recovery', 'recovery administrator');
+  }
+}
+
+/** First-party client ids are names; registered ones are long tokens. */
+function shortClient(client: string): string {
+  return client.length > 24 ? `${client.slice(0, 12)}…` : client;
+}
+
diff --git a/src/lib/layout.ts b/src/lib/layout.ts
index e37806d..3b4ab50 100644
--- a/src/lib/layout.ts
+++ b/src/lib/layout.ts
@@ -76,6 +76,11 @@ function checkSpecialLink(
     return { visible: canGet ? canGet('sysSpamLlm') : true, enterprise: false };
   }
 
+  // inbuxa: the audit log, for whoever may read it (AU-9).
+  if (viewName === 'CustomComponent/AuditLog') {
+    return { visible: canGet ? canGet('sysAudit') : true, enterprise: false };
+  }
+
   if (viewName.startsWith('CustomComponent/')) {
     return { visible: true, enterprise: false };
   }