diff --git a/apps/hq-web/src/api.ts b/apps/hq-web/src/api.ts
index f8181a8..aa7f6bc 100644
--- a/apps/hq-web/src/api.ts
+++ b/apps/hq-web/src/api.ts
@@ -429,6 +429,43 @@ export const putTemplateSettings = (
 export const uploadTemplateLogo = (dataUri: string): Promise<string> =>
   apiFetch<{ logo: string }>('/settings/template/logo', { method: 'POST', body: JSON.stringify({ dataUri }) }).then((r) => r.logo)
 
+// ---------- module → client roster (spec §10) ----------
+
+export interface ModuleClientRow {
+  clientId: string; clientName: string; clientCode: string
+  status: string; kind: Kind; edition: string
+  nextRenewal: string | null; pricePaise: number | null
+}
+export interface ModuleClientsPage {
+  clients: ModuleClientRow[]; total: number; page: number; pageSize: number; totalPricePaise: number
+}
+export const getModuleClients = (moduleId: string, page = 1): Promise<ModuleClientsPage> =>
+  apiFetch<ModuleClientsPage & { ok: boolean }>(`/modules/${moduleId}/clients?page=${page}`)
+export const notifyModuleClients = (
+  moduleId: string, body: { subject: string; body: string },
+): Promise<{ sent: number; total: number; failed: { client: string; error: string }[] }> =>
+  apiFetch(`/modules/${moduleId}/notify`, { method: 'POST', body: JSON.stringify(body) })
+/** CSV export needs the bearer header an <a href> can't carry — blob + transient anchor. */
+export async function downloadModuleClientsCsv(moduleId: string, moduleCode: string): Promise<void> {
+  const token = localStorage.getItem(TOKEN_KEY) ?? ''
+  const res = await fetch(`/api/modules/${moduleId}/clients.csv`, {
+    headers: token !== '' ? { authorization: `Bearer ${token}` } : {},
+  })
+  if (!res.ok) {
+    const body = (await res.json().catch(() => ({}))) as { error?: string }
+    throw new Error(body.error ?? `CSV failed: HTTP ${res.status}`)
+  }
+  const blob = await res.blob()
+  const url = URL.createObjectURL(blob)
+  const a = document.createElement('a')
+  a.href = url
+  a.download = `module-${moduleCode}-clients.csv`
+  document.body.appendChild(a)
+  a.click()
+  a.remove()
+  URL.revokeObjectURL(url)
+}
+
 /** The PDF route needs the bearer header, which an <iframe src> can't carry — fetch a blob instead. */
 export async function fetchPdfBlob(documentId: string): Promise<Blob> {
   const token = localStorage.getItem(TOKEN_KEY) ?? ''
diff --git a/apps/hq-web/src/pages/Modules.tsx b/apps/hq-web/src/pages/Modules.tsx
index b8a7c20..f07e399 100644
--- a/apps/hq-web/src/pages/Modules.tsx
+++ b/apps/hq-web/src/pages/Modules.tsx
@@ -2,7 +2,8 @@ import { useMemo, useState } from 'react'
 import { formatINR, fromRupees } from '@sims/domain'
 import { Badge, Button, DataTable, EmptyState, ErrorState, Field, Notice, PageHeader, Skeleton, Toolbar } from '@sims/ui'
 import {
-  addPrice, createModule, getModules, getPrices, patchModule, previewSample, role,
+  addPrice, createModule, downloadModuleClientsCsv, getModuleClients, getModules, getPrices,
+  notifyModuleClients, patchModule, previewSample, role,
   KIND_LABEL, type Kind, type Module,
 } from '../api'
 import { LivePreview } from '../components/LivePreview'
@@ -53,6 +54,7 @@ export function Modules() {
       )}
       {selected !== undefined && (
         <>
+          <ModuleClients key={`mc-${selected.id}`} module={selected} />
           <QuoteContent key={selected.id} module={selected} isOwner={isOwner} onSaved={() => modules.reload()} />
           <PriceBook module={selected} isOwner={isOwner} />
         </>
@@ -61,6 +63,98 @@ export function Modules() {
   )
 }
 
+/**
+ * "Who's on this module" roster (spec §10): every ACTIVE client link with what
+ * it pays and its next renewal, plus Notify-all (owner/manager) and CSV export.
+ */
+function ModuleClients(props: { module: Module }) {
+  const managerial = role() === 'owner' || role() === 'manager'
+  const [page, setPage] = useState(1)
+  const roster = useData(() => getModuleClients(props.module.id, page), [props.module.id, page])
+  const [notifying, setNotifying] = useState(false)
+  const [subject, setSubject] = useState('')
+  const [bodyText, setBodyText] = useState('')
+  const [busy, setBusy] = useState(false)
+  const [result, setResult] = useState<string | undefined>()
+  const [err, setErr] = useState<string | undefined>()
+
+  const doNotify = () => {
+    setBusy(true); setErr(undefined); setResult(undefined)
+    notifyModuleClients(props.module.id, { subject, body: bodyText })
+      .then((out) => {
+        setResult(`Sent ${out.sent}/${out.total}`
+          + (out.failed.length > 0 ? ` — unreached: ${out.failed.map((f) => `${f.client} (${f.error})`).join(', ')}` : ''))
+        setNotifying(false)
+      })
+      .catch((e: Error) => setErr(e.message))
+      .finally(() => setBusy(false))
+  }
+
+  const data = roster.data
+  const pages = data !== undefined ? Math.max(1, Math.ceil(data.total / data.pageSize)) : 1
+  return (
+    <section>
+      <h2>Clients on this module</h2>
+      <Toolbar>
+        {managerial && (
+          <Button onClick={() => setNotifying((v) => !v)}>
+            {notifying ? 'Close composer' : `Notify all${data !== undefined ? ` (${data.total})` : ''}`}
+          </Button>
+        )}
+        <Button onClick={() => { downloadModuleClientsCsv(props.module.id, props.module.code).catch((e: Error) => setErr(e.message)) }}>
+          Export CSV
+        </Button>
+      </Toolbar>
+      {notifying && managerial && (
+        <div className="wf-form">
+          <Field label="Subject"><input value={subject} onChange={(e) => setSubject(e.target.value)} /></Field>
+          <Field label="Message">
+            <textarea rows={4} value={bodyText} onChange={(e) => setBodyText(e.target.value)} />
+          </Field>
+          <Button
+            tone="primary"
+            onClick={() => { if (!busy && subject.trim() !== '' && bodyText.trim() !== '') doNotify() }}
+          >
+            {busy ? 'Sending…' : `Send to every client on ${props.module.code}`}
+          </Button>
+        </div>
+      )}
+      {result !== undefined && <Notice tone="ok">{result}</Notice>}
+      {err !== undefined && <Notice tone="err">{err}</Notice>}
+      {roster.error !== undefined ? <ErrorState message={roster.error} onRetry={roster.reload} />
+        : data === undefined ? <Skeleton rows={4} />
+        : data.total === 0 ? <EmptyState>No client is on this module yet.</EmptyState> : (
+        <>
+          <DataTable
+            columns={[
+              { key: 'client', label: 'Client' }, { key: 'code', label: 'Code', mono: true },
+              { key: 'status', label: 'Status' }, { key: 'kindEdition', label: 'Kind · Edition' },
+              { key: 'pays', label: 'Pays' }, { key: 'renewal', label: 'Next renewal' },
+            ]}
+            rows={data.clients.map((c) => ({
+              client: c.clientName, code: c.clientCode,
+              status: <Badge tone={c.status === 'live' ? 'ok' : undefined}>{c.status}</Badge>,
+              kindEdition: `${KIND_LABEL[c.kind]} · ${c.edition}`,
+              pays: c.pricePaise !== null ? formatINR(c.pricePaise) : '—',
+              renewal: c.nextRenewal ?? '—',
+            }))}
+          />
+          <div className="wf-pager">
+            <span>{data.total} client(s) · total {formatINR(data.totalPricePaise)} at current price book</span>
+            {pages > 1 && (
+              <>
+                <Button onClick={() => { if (page > 1) setPage((p) => p - 1) }}>‹ Prev</Button>
+                <span>Page {data.page}/{pages}</span>
+                <Button onClick={() => { if (page < pages) setPage((p) => p + 1) }}>Next ›</Button>
+              </>
+            )}
+          </div>
+        </>
+      )}
+    </section>
+  )
+}
+
 /** Per-module "what's included" lines — prefilled into the composer, printed under the quote line. */
 function QuoteContent(props: { module: Module; isOwner: boolean; onSaved: () => void }) {
   const [text, setText] = useState(props.module.quoteContent.join('\n'))
diff --git a/apps/hq/src/api.ts b/apps/hq/src/api.ts
index 55bd7c9..ebe2136 100644
--- a/apps/hq/src/api.ts
+++ b/apps/hq/src/api.ts
@@ -12,7 +12,7 @@ import {
 } from './repos-employees'
 import {
   assignModule, createModule, getClientModule, getModule, listClientModules,
-  listModules, listPrices, setPrice, updateClientModule, updateModule,
+  listClientsByModule, listModules, listPrices, setPrice, updateClientModule, updateModule,
   type AssignModuleInput, type ClientModulePatch, type ModuleInput, type ModulePatch,
   type PriceInput,
 } from './repos-modules'
@@ -54,7 +54,8 @@ import { clientProfitability, duesAging, moduleRevenue, type DateRange } from '.
 import { documentHtml, documentHtmlSample } from './templates'
 import { renderPdf } from './pdf'
 import { emailStatus } from './repos-email'
-import { sendDocumentEmail, type GmailDeps } from './gmail'
+import { sendDocumentEmail, sendReminderEmail, type GmailDeps } from './gmail'
+import { writeAudit } from './audit'
 
 const staffId = (res: Response): string => (res.locals['staff'] as { id: string }).id
 
@@ -271,6 +272,100 @@ export function apiRouter(
     }
   })
 
+  // ---------- module → client roster (spec §10, D-ROSTER) ----------
+  r.get('/modules/:id/clients', requireAuth, (req, res) => {
+    const id = String(req.params['id'] ?? '')
+    if (getModule(db, id) === null) {
+      res.status(404).json({ ok: false, error: 'Module not found' }); return
+    }
+    const num = (v: unknown): number | undefined =>
+      typeof v === 'string' && v !== '' && Number.isFinite(Number(v)) ? Number(v) : undefined
+    const page = num(req.query['page'])
+    const pageSize = num(req.query['pageSize'])
+    res.json({
+      ok: true,
+      ...listClientsByModule(db, id, {
+        ...(page !== undefined ? { page } : {}), ...(pageSize !== undefined ? { pageSize } : {}),
+      }),
+    })
+  })
+  // CSV export streams EVERY row — an export never silently caps (rule 8).
+  r.get('/modules/:id/clients.csv', requireAuth, (req, res) => {
+    const id = String(req.params['id'] ?? '')
+    const mod = getModule(db, id)
+    if (mod === null) { res.status(404).json({ ok: false, error: 'Module not found' }); return }
+    const esc = (v: string): string => /[",\n]/.test(v) ? `"${v.replaceAll('"', '""')}"` : v
+    const lines = ['client_code,client_name,status,kind,edition,price_paise,next_renewal']
+    for (let page = 1; ; page++) {
+      const batch = listClientsByModule(db, id, { page, pageSize: 200 })
+      for (const c of batch.clients) {
+        lines.push([
+          esc(c.clientCode), esc(c.clientName), c.status, c.kind, esc(c.edition),
+          c.pricePaise === null ? '' : String(c.pricePaise), c.nextRenewal ?? '',
+        ].join(','))
+      }
+      if (page * batch.pageSize >= batch.total) break
+    }
+    res.setHeader('Content-Type', 'text/csv; charset=utf-8')
+    res.setHeader('Content-Disposition', `attachment; filename="module-${mod.code}-clients.csv"`)
+    res.send(lines.join('\n') + '\n')
+  })
+  // Notify every client on the module (owner/manager — bulk client email is privileged, A6).
+  // Ad-hoc human broadcast (A5): subject/body typed by the sender, not dated config.
+  r.post('/modules/:id/notify', requireAuth, (req, res) => {
+    const viewer = res.locals['staff'] as { id: string; role: string }
+    if (!isManagerial(viewer.role)) {
+      res.status(403).json({ ok: false, error: 'Owner or manager only' }); return
+    }
+    const id = String(req.params['id'] ?? '')
+    const mod = getModule(db, id)
+    if (mod === null) { res.status(404).json({ ok: false, error: 'Module not found' }); return }
+    const body = req.body as { subject?: unknown; body?: unknown }
+    const subject = typeof body.subject === 'string' ? body.subject.trim() : ''
+    const bodyText = typeof body.body === 'string' ? body.body.trim() : ''
+    if (subject === '' || bodyText === '') {
+      res.status(400).json({ ok: false, error: 'subject and body are required' }); return
+    }
+    const status = emailStatus(db)
+    if (!status.connected) { res.status(409).json({ ok: false, error: 'gmail-not-connected' }); return }
+    if (status.dead) { res.status(409).json({ ok: false, error: 'gmail-token-dead' }); return }
+    // Resolve the FULL roster (internally paginated) before sending anything.
+    const targets: { clientId: string; clientName: string; email: string | undefined }[] = []
+    for (let page = 1; ; page++) {
+      const batch = listClientsByModule(db, id, { page, pageSize: 200 })
+      for (const c of batch.clients) {
+        const client = getClient(db, c.clientId)
+        targets.push({
+          clientId: c.clientId, clientName: c.clientName,
+          email: client?.contacts.find((ct) => ct.email !== undefined && ct.email !== '')?.email,
+        })
+      }
+      if (page * batch.pageSize >= batch.total) break
+    }
+    void (async () => {
+      let sent = 0
+      const failed: { client: string; error: string }[] = []
+      for (const t of targets) {
+        if (t.email === undefined) {
+          failed.push({ client: t.clientName, error: 'no contact email' })
+          continue
+        }
+        // sendReminderEmail logs every attempt to email_log; one audit row per
+        // recipient records who broadcast what to whom (rule 6).
+        const out = await sendReminderEmail(db, gmail(), { to: t.email, subject, bodyText })
+        writeAudit(db, viewer.id, 'notify', 'client', t.clientId, undefined, {
+          moduleId: id, subject, status: out.ok ? 'sent' : 'failed',
+          ...(out.ok ? {} : { error: out.error }),
+        })
+        if (out.ok) sent += 1
+        else failed.push({ client: t.clientName, error: out.error })
+        if (!out.ok && out.error === 'gmail-token-dead') break // account died mid-run: stop, report the rest honestly
+      }
+      // Warn, never truncate: every unreached client is named in the response.
+      res.json({ ok: true, sent, failed, total: targets.length })
+    })()
+  })
+
   // ---------- client modules ----------
   r.get('/clients/:id/modules', requireAuth, (req, res) => {
     const id = String(req.params['id'] ?? '')
diff --git a/apps/hq/src/repos-modules.ts b/apps/hq/src/repos-modules.ts
index fcb9b95..f2c8124 100644
--- a/apps/hq/src/repos-modules.ts
+++ b/apps/hq/src/repos-modules.ts
@@ -195,6 +195,65 @@ export function listClientModules(db: DB, clientId: string): ClientModule[] {
   return rows.map(toClientModule)
 }
 
+// ---------- module → client roster (spec §10, D-ROSTER) ----------
+
+export interface ModuleClientRow {
+  clientId: string; clientName: string; clientCode: string
+  status: ClientModuleStatus; kind: Kind; edition: string
+  nextRenewal: string | null
+  /** Price-book rate for this link's kind/edition on the roster date; null = no price row. */
+  pricePaise: number | null
+}
+
+export interface ModuleClientsPage {
+  clients: ModuleClientRow[]
+  total: number; page: number; pageSize: number
+  /** Sum of price-book rates across ALL active links (not just this page). */
+  totalPricePaise: number
+}
+
+/**
+ * The reverse lookup: every client on a module (support/impact + revenue lens).
+ * ACTIVE links only — `active=0` assignments are historical and deliberately
+ * excluded (stated here, not silently dropped). Paginated with a true total
+ * (rule 8); price per row via the dated price book on `onDate`.
+ */
+export function listClientsByModule(
+  db: DB, moduleId: string,
+  opts: { page?: number; pageSize?: number; onDate?: string } = {},
+): ModuleClientsPage {
+  const page = Math.max(1, opts.page ?? 1)
+  const pageSize = Math.min(200, Math.max(1, opts.pageSize ?? 50))
+  const onDate = opts.onDate ?? new Date().toISOString().slice(0, 10)
+  const total = (db.prepare(
+    `SELECT COUNT(*) AS n FROM client_module WHERE module_id=? AND active=1`,
+  ).get(moduleId) as { n: number }).n
+  const rows = db.prepare(
+    `SELECT cm.client_id, c.name AS client_name, c.code AS client_code,
+            cm.status, cm.kind, cm.edition, cm.next_renewal
+     FROM client_module cm JOIN client c ON c.id = cm.client_id
+     WHERE cm.module_id=? AND cm.active=1
+     ORDER BY c.name, cm.id
+     LIMIT ? OFFSET ?`,
+  ).all(moduleId, pageSize, (page - 1) * pageSize) as {
+    client_id: string; client_name: string; client_code: string
+    status: string; kind: string; edition: string; next_renewal: string | null
+  }[]
+  const clients = rows.map((r): ModuleClientRow => ({
+    clientId: r.client_id, clientName: r.client_name, clientCode: r.client_code,
+    status: r.status as ClientModuleStatus, kind: r.kind as Kind, edition: r.edition,
+    nextRenewal: r.next_renewal,
+    pricePaise: priceOn(db, moduleId, r.kind as Kind, r.edition, onDate),
+  }))
+  // Revenue total spans ALL active links, not the visible page (the footer figure).
+  const allLinks = db.prepare(
+    `SELECT kind, edition FROM client_module WHERE module_id=? AND active=1`,
+  ).all(moduleId) as { kind: string; edition: string }[]
+  const totalPricePaise = allLinks.reduce(
+    (sum, l) => sum + (priceOn(db, moduleId, l.kind as Kind, l.edition, onDate) ?? 0), 0)
+  return { clients, total, page, pageSize, totalPricePaise }
+}
+
 export interface AssignModuleInput {
   clientId: string; moduleId: string; kind: Kind
   edition?: string; status?: ClientModuleStatus
diff --git a/apps/hq/test/module-roster.test.ts b/apps/hq/test/module-roster.test.ts
new file mode 100644
index 0000000..f630e4c
--- /dev/null
+++ b/apps/hq/test/module-roster.test.ts
@@ -0,0 +1,181 @@
+// apps/hq/test/module-roster.test.ts — Phase 10: module → client roster + notify + CSV (spec §10)
+import express from 'express'
+import { describe, it, expect, afterAll } from 'vitest'
+import { openDb, type DB } from '../src/db'
+import { seedIfEmpty } from '../src/seed'
+import { createStaff } from '../src/auth'
+import { createClient } from '../src/repos-clients'
+import {
+  assignModule, createModule, listClientsByModule, setPrice, updateClientModule,
+} from '../src/repos-modules'
+import { saveAccount } from '../src/repos-email'
+import { encrypt } from '../src/crypto'
+import { listAudit } from '../src/audit'
+import { apiRouter } from '../src/api'
+
+const KEY = '11'.repeat(32)
+const fakePdf = async () => Buffer.from('%PDF-fake')
+
+function world() {
+  const db = openDb(':memory:'); seedIfEmpty(db)
+  const m = createModule(db, 'u1', { code: 'CORE', name: 'Core Banking' })
+  setPrice(db, 'u1', { moduleId: m.id, kind: 'yearly', pricePaise: 9_000_00, effectiveFrom: '2026-01-01' })
+  const mkClient = (name: string, email?: string) => createClient(db, 'u1', {
+    name, stateCode: '32',
+    contacts: email !== undefined ? [{ name: 'C', email }] : [],
+  })
+  return { db, m, mkClient }
+}
+
+describe('listClientsByModule', () => {
+  it('lists active links with price + renewal, ordered by client name, with a true total', () => {
+    const { db, m, mkClient } = world()
+    const a = mkClient('Acme Bank'); const z = mkClient('Zeta CCS'); const b = mkClient('Beta Coop')
+    const cmA = assignModule(db, 'u1', { clientId: a.id, moduleId: m.id, kind: 'yearly' })
+    updateClientModule(db, 'u1', cmA.id, { nextRenewal: '2026-09-01' })
+    assignModule(db, 'u1', { clientId: z.id, moduleId: m.id, kind: 'yearly' })
+    assignModule(db, 'u1', { clientId: b.id, moduleId: m.id, kind: 'yearly' })
+    const page = listClientsByModule(db, m.id, { onDate: '2026-07-17' })
+    expect(page.total).toBe(3)
+    expect(page.clients.map((c) => c.clientName)).toEqual(['Acme Bank', 'Beta Coop', 'Zeta CCS'])
+    expect(page.clients[0]).toMatchObject({ pricePaise: 9_000_00, nextRenewal: '2026-09-01' })
+    expect(page.totalPricePaise).toBe(27_000_00) // spans all links
+  })
+
+  it('excludes inactive links (historical assignments) and paginates with a stable total', () => {
+    const { db, m, mkClient } = world()
+    for (let i = 0; i < 5; i++) {
+      assignModule(db, 'u1', { clientId: mkClient(`Bank ${i}`).id, moduleId: m.id, kind: 'yearly' })
+    }
+    const dead = assignModule(db, 'u1', { clientId: mkClient('Gone Bank').id, moduleId: m.id, kind: 'yearly' })
+    db.prepare(`UPDATE client_module SET active=0 WHERE id=?`).run(dead.id)
+    const p1 = listClientsByModule(db, m.id, { page: 1, pageSize: 2 })
+    const p3 = listClientsByModule(db, m.id, { page: 3, pageSize: 2 })
+    expect(p1.total).toBe(5) // Gone Bank excluded
+    expect(p1.clients).toHaveLength(2)
+    expect(p3.clients).toHaveLength(1)
+    expect([...p1.clients, ...p3.clients].some((c) => c.clientName === 'Gone Bank')).toBe(false)
+  })
+
+  it('a module nobody uses returns an honest empty page', () => {
+    const { db, m } = world()
+    const page = listClientsByModule(db, m.id)
+    expect(page).toMatchObject({ total: 0, clients: [], totalPricePaise: 0 })
+  })
+})
+
+// ---------- routes ----------
+
+function appWith(fetchImpl: typeof fetch) {
+  const { db, m, mkClient } = world()
+  createStaff(db, { email: 'owner@test.in', displayName: 'Owner', role: 'owner', password: 'owner-password' })
+  createStaff(db, { email: 'staff@test.in', displayName: 'Staff', role: 'staff', password: 'staff-password' })
+  saveAccount(db, 'us@tecnostac.com', encrypt('refresh-token', KEY))
+  const withMail = mkClient('Acme Bank', 'ravi@acme.in')
+  const noMail = mkClient('Beta Coop') // no contact email — must be reported, not skipped silently
+  assignModule(db, 'u1', { clientId: withMail.id, moduleId: m.id, kind: 'yearly' })
+  assignModule(db, 'u1', { clientId: noMail.id, moduleId: m.id, kind: 'yearly' })
+  const app = express(); app.use(express.json()); app.locals['db'] = db
+  app.use('/api', apiRouter(db, { f: fetchImpl, clientId: 'cid', clientSecret: 'sec', keyHex: KEY }, fakePdf))
+  const server = app.listen(0)
+  const baseUrl = `http://localhost:${(server.address() as { port: number }).port}/api`
+  return { db, server, baseUrl, m }
+}
+
+const okFetch = (async (url: string) =>
+  new Response(JSON.stringify(String(url).includes('/token') ? { access_token: 'at' } : { id: 'gmsg-1' }),
+    { status: 200 })) as typeof fetch
+
+async function login(baseUrl: string, email: string, password: string) {
+  return (await (await fetch(`${baseUrl}/auth/login`, {
+    method: 'POST', headers: { 'content-type': 'application/json' },
+    body: JSON.stringify({ email, password }),
+  })).json() as { token: string }).token
+}
+
+describe('module roster routes', () => {
+  const servers: { close: () => void }[] = []
+  afterAll(() => { for (const s of servers) s.close() })
+
+  it('GET /modules/:id/clients returns the paginated roster to any signed-in user', async () => {
+    const ctx = appWith(okFetch); servers.push(ctx.server)
+    const token = await login(ctx.baseUrl, 'staff@test.in', 'staff-password')
+    const res = await fetch(`${ctx.baseUrl}/modules/${ctx.m.id}/clients`, {
+      headers: { authorization: `Bearer ${token}` },
+    })
+    const json = await res.json() as { ok: boolean; total: number; clients: { clientName: string }[] }
+    expect(res.status).toBe(200)
+    expect(json.total).toBe(2)
+    expect(json.clients.map((c) => c.clientName)).toEqual(['Acme Bank', 'Beta Coop'])
+  })
+
+  it('GET /modules/:id/clients.csv exports every row as an attachment', async () => {
+    const ctx = appWith(okFetch); servers.push(ctx.server)
+    const token = await login(ctx.baseUrl, 'staff@test.in', 'staff-password')
+    const res = await fetch(`${ctx.baseUrl}/modules/${ctx.m.id}/clients.csv`, {
+      headers: { authorization: `Bearer ${token}` },
+    })
+    expect(res.status).toBe(200)
+    expect(res.headers.get('content-type')).toContain('text/csv')
+    expect(res.headers.get('content-disposition')).toContain('module-CORE-clients.csv')
+    const body = await res.text()
+    const rows = body.trim().split('\n')
+    expect(rows[0]).toBe('client_code,client_name,status,kind,edition,price_paise,next_renewal')
+    expect(rows).toHaveLength(3) // header + 2 clients
+    expect(body).toContain('Acme Bank')
+    expect(body).toContain('Beta Coop')
+  })
+
+  it('POST /modules/:id/notify is owner/manager-only', async () => {
+    const ctx = appWith(okFetch); servers.push(ctx.server)
+    const token = await login(ctx.baseUrl, 'staff@test.in', 'staff-password')
+    const res = await fetch(`${ctx.baseUrl}/modules/${ctx.m.id}/notify`, {
+      method: 'POST',
+      headers: { 'content-type': 'application/json', authorization: `Bearer ${token}` },
+      body: JSON.stringify({ subject: 'Update', body: 'RTGS window changes tonight.' }),
+    })
+    expect(res.status).toBe(403)
+  })
+
+  it('notify sends to every reachable client, names the unreachable, and audits per recipient', async () => {
+    const ctx = appWith(okFetch); servers.push(ctx.server)
+    const token = await login(ctx.baseUrl, 'owner@test.in', 'owner-password')
+    const res = await fetch(`${ctx.baseUrl}/modules/${ctx.m.id}/notify`, {
+      method: 'POST',
+      headers: { 'content-type': 'application/json', authorization: `Bearer ${token}` },
+      body: JSON.stringify({ subject: 'Core Banking maintenance', body: 'Window: Sunday 02:00.' }),
+    })
+    const json = await res.json() as { ok: boolean; sent: number; total: number; failed: { client: string; error: string }[] }
+    expect(res.status).toBe(200)
+    expect(json.sent).toBe(1) // Acme has a contact email
+    expect(json.total).toBe(2)
+    expect(json.failed).toEqual([{ client: 'Beta Coop', error: 'no contact email' }])
+    const log = ctx.db.prepare(`SELECT to_addr, status, subject FROM email_log ORDER BY id DESC LIMIT 1`)
+      .get() as { to_addr: string; status: string; subject: string }
+    expect(log).toMatchObject({ to_addr: 'ravi@acme.in', status: 'sent', subject: 'Core Banking maintenance' })
+    // One audit row per attempted recipient; the unreachable client is named in
+    // the response (warn-not-truncate) but no send happened, so nothing to audit.
+    const audits = listAudit(ctx.db).filter((a) => a.action === 'notify')
+    expect(audits).toHaveLength(1)
+    expect(JSON.parse(audits[0]!.after_json ?? '{}')).toMatchObject({ status: 'sent', subject: 'Core Banking maintenance' })
+  })
+
+  it('notify validates subject/body and the gmail account before sending anything', async () => {
+    const ctx = appWith(okFetch); servers.push(ctx.server)
+    const token = await login(ctx.baseUrl, 'owner@test.in', 'owner-password')
+    const bad = await fetch(`${ctx.baseUrl}/modules/${ctx.m.id}/notify`, {
+      method: 'POST',
+      headers: { 'content-type': 'application/json', authorization: `Bearer ${token}` },
+      body: JSON.stringify({ subject: '', body: '' }),
+    })
+    expect(bad.status).toBe(400)
+    ctx.db.prepare(`DELETE FROM email_account`).run()
+    const disconnected = await fetch(`${ctx.baseUrl}/modules/${ctx.m.id}/notify`, {
+      method: 'POST',
+      headers: { 'content-type': 'application/json', authorization: `Bearer ${token}` },
+      body: JSON.stringify({ subject: 'S', body: 'B' }),
+    })
+    expect(disconnected.status).toBe(409)
+    expect(ctx.db.prepare(`SELECT COUNT(*) AS n FROM email_log`).get()).toMatchObject({ n: 0 })
+  })
+})