diff --git a/apps/hq/src/api.ts b/apps/hq/src/api.ts
index 1e671f4..496d4bd 100644
--- a/apps/hq/src/api.ts
+++ b/apps/hq/src/api.ts
@@ -23,6 +23,10 @@ import {
   createRecurringPlan, deactivateRecurringPlan, getRecurringPlan, listRecurringPlans,
   updateRecurringPlan, type CreateRecurringInput, type RecurringPatch,
 } from './repos-recurring'
+import {
+  amcPaidStatus, createAmc, deactivateAmc, generateAmcRenewalInvoice, getAmc, listAmc,
+  updateAmc, type AmcPatch, type CreateAmcInput,
+} from './repos-amc'
 import { documentHtml } from './templates'
 import { renderPdf } from './pdf'
 import { emailStatus } from './repos-email'
@@ -325,6 +329,49 @@ export function apiRouter(db: DB, gmailDeps?: Partial<GmailDeps>): Router {
     res.json({ ok: true, plan: deactivateRecurringPlan(db, staffId(res), id) })
   })
 
+  // ---------- amc ----------
+  r.get('/clients/:id/amc', requireAuth, (req, res) => {
+    const id = String(req.params['id'] ?? '')
+    if (getClient(db, id) === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
+    const contracts = listAmc(db, id).map((a) => ({ ...a, paidStatus: amcPaidStatus(db, a) }))
+    res.json({ ok: true, contracts })
+  })
+  r.post('/clients/:id/amc', requireAuth, requireOwner, (req, res) => {
+    const id = String(req.params['id'] ?? '')
+    if (getClient(db, id) === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
+    try {
+      const amc = createAmc(db, staffId(res), { ...(req.body as Omit<CreateAmcInput, 'clientId'>), clientId: id })
+      res.json({ ok: true, contract: { ...amc, paidStatus: amcPaidStatus(db, amc) } })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
+  r.patch('/amc/:id', requireAuth, requireOwner, (req, res) => {
+    const id = String(req.params['id'] ?? '')
+    if (getAmc(db, id) === null) { res.status(404).json({ ok: false, error: 'AMC contract not found' }); return }
+    try {
+      const amc = updateAmc(db, staffId(res), id, req.body as AmcPatch)
+      res.json({ ok: true, contract: { ...amc, paidStatus: amcPaidStatus(db, amc) } })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
+  r.post('/amc/:id/deactivate', requireAuth, requireOwner, (req, res) => {
+    const id = String(req.params['id'] ?? '')
+    if (getAmc(db, id) === null) { res.status(404).json({ ok: false, error: 'AMC contract not found' }); return }
+    const amc = deactivateAmc(db, staffId(res), id)
+    res.json({ ok: true, contract: { ...amc, paidStatus: amcPaidStatus(db, amc) } })
+  })
+  r.post('/amc/:id/renewal-invoice', requireAuth, requireOwner, (req, res) => {
+    const id = String(req.params['id'] ?? '')
+    if (getAmc(db, id) === null) { res.status(404).json({ ok: false, error: 'AMC contract not found' }); return }
+    try {
+      res.json({ ok: true, document: generateAmcRenewalInvoice(db, staffId(res), id) })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
+
   // ---------- payments ----------
   r.post('/payments', requireAuth, (req, res) => {
     try {
diff --git a/apps/hq/src/repos-amc.ts b/apps/hq/src/repos-amc.ts
new file mode 100644
index 0000000..cd44953
--- /dev/null
+++ b/apps/hq/src/repos-amc.ts
@@ -0,0 +1,145 @@
+import { uuidv7 } from '@sims/domain'
+import { writeAudit } from './audit'
+import type { DB } from './db'
+import { getClient } from './repos-clients'
+import { createDraft, getDocument, issueDocument, type Doc } from './repos-documents'
+
+/** AMC contracts — plain functions over the handle (D12 pattern). Paid state is
+ *  derived from the linked invoice's settlement; legacy_paid is a manual flag for
+ *  imported contracts only, so there is one source of truth and no drift. */
+
+export interface AmcContract {
+  id: string; clientId: string; coverage: string; periodFrom: string; periodTo: string
+  amountPaise: number; renewalReminderDays: number; legacyPaid: boolean | null
+  invoiceDocId: string | null; active: boolean
+}
+
+interface AmcRow {
+  id: string; client_id: string; coverage: string; period_from: string; period_to: string
+  amount_paise: number; renewal_reminder_days: number; legacy_paid: number | null
+  invoice_doc_id: string | null; active: number
+}
+
+function toAmc(r: AmcRow): AmcContract {
+  return {
+    id: r.id, clientId: r.client_id, coverage: r.coverage,
+    periodFrom: r.period_from, periodTo: r.period_to, amountPaise: r.amount_paise,
+    renewalReminderDays: r.renewal_reminder_days,
+    legacyPaid: r.legacy_paid === null ? null : r.legacy_paid === 1,
+    invoiceDocId: r.invoice_doc_id, active: r.active === 1,
+  }
+}
+
+export function getAmc(db: DB, id: string): AmcContract | null {
+  const row = db.prepare(`SELECT * FROM amc_contract WHERE id=?`).get(id) as AmcRow | undefined
+  return row === undefined ? null : toAmc(row)
+}
+
+export function listAmc(db: DB, clientId: string): AmcContract[] {
+  const rows = db.prepare(`SELECT * FROM amc_contract WHERE client_id=? ORDER BY id DESC`).all(clientId) as AmcRow[]
+  return rows.map(toAmc)
+}
+
+export interface CreateAmcInput {
+  clientId: string; coverage?: string; periodFrom: string; periodTo: string
+  amountPaise: number; renewalReminderDays?: number; legacyPaid?: boolean
+}
+
+export function createAmc(db: DB, userId: string, input: CreateAmcInput): AmcContract {
+  if (getClient(db, input.clientId) === null) throw new Error('Client not found')
+  if (!Number.isInteger(input.amountPaise) || input.amountPaise < 0) {
+    throw new Error('amountPaise must be a non-negative integer (paise)')
+  }
+  const id = uuidv7()
+  db.prepare(
+    `INSERT INTO amc_contract (id, client_id, coverage, period_from, period_to, amount_paise,
+       renewal_reminder_days, legacy_paid, invoice_doc_id, active)
+     VALUES (?, ?, ?, ?, ?, ?, ?, ?, NULL, 1)`,
+  ).run(
+    id, input.clientId, input.coverage ?? '', input.periodFrom, input.periodTo, input.amountPaise,
+    input.renewalReminderDays ?? 30, input.legacyPaid === undefined ? null : input.legacyPaid ? 1 : 0,
+  )
+  const amc = getAmc(db, id)!
+  writeAudit(db, userId, 'create', 'amc_contract', id, undefined, amc)
+  return amc
+}
+
+export interface AmcPatch {
+  coverage?: string; periodFrom?: string; periodTo?: string; amountPaise?: number
+  renewalReminderDays?: number; legacyPaid?: boolean | null; active?: boolean
+}
+
+export function updateAmc(db: DB, userId: string, id: string, patch: AmcPatch): AmcContract {
+  const before = getAmc(db, id)
+  if (before === null) throw new Error('AMC contract not found')
+  const sets: string[] = []
+  const args: unknown[] = []
+  if (patch.coverage !== undefined) { sets.push('coverage=?'); args.push(patch.coverage) }
+  if (patch.periodFrom !== undefined) { sets.push('period_from=?'); args.push(patch.periodFrom) }
+  if (patch.periodTo !== undefined) { sets.push('period_to=?'); args.push(patch.periodTo) }
+  if (patch.amountPaise !== undefined) { sets.push('amount_paise=?'); args.push(patch.amountPaise) }
+  if (patch.renewalReminderDays !== undefined) { sets.push('renewal_reminder_days=?'); args.push(patch.renewalReminderDays) }
+  if (patch.legacyPaid !== undefined) { sets.push('legacy_paid=?'); args.push(patch.legacyPaid === null ? null : patch.legacyPaid ? 1 : 0) }
+  if (patch.active !== undefined) { sets.push('active=?'); args.push(patch.active ? 1 : 0) }
+  if (sets.length > 0) {
+    args.push(id)
+    db.prepare(`UPDATE amc_contract SET ${sets.join(', ')} WHERE id=?`).run(...args)
+  }
+  const after = getAmc(db, id)!
+  writeAudit(db, userId, 'update', 'amc_contract', id, before, after)
+  return after
+}
+
+export function deactivateAmc(db: DB, userId: string, id: string): AmcContract {
+  return updateAmc(db, userId, id, { active: false })
+}
+
+/** Renewal invoice for an AMC: one line on the seeded AMC module, priced at the
+ *  contract amount, issued and linked back via invoice_doc_id. */
+export function generateAmcRenewalInvoice(db: DB, userId: string, amcId: string): Doc {
+  const amc = getAmc(db, amcId)
+  if (amc === null) throw new Error('AMC contract not found')
+  if (amc.invoiceDocId !== null) {
+    const existing = getDocument(db, amc.invoiceDocId)
+    if (existing !== null && existing.status !== 'cancelled' && outstandingOf(db, existing.id) > 0) {
+      throw new Error(`AMC already has an unpaid renewal invoice ${existing.docNo}`)
+    }
+  }
+  const amcModule = db.prepare(`SELECT id FROM module WHERE code='AMC'`).get() as { id: string } | undefined
+  if (amcModule === undefined) throw new Error('AMC module missing — run the seed')
+  return db.transaction(() => {
+    const draft = createDraft(db, userId, {
+      docType: 'INVOICE', clientId: amc.clientId,
+      lines: [{
+        moduleId: amcModule.id, description: amc.coverage !== '' ? amc.coverage : 'Annual Maintenance',
+        qty: 1, kind: 'yearly', unitPricePaise: amc.amountPaise,
+      }],
+    })
+    const inv = issueDocument(db, userId, draft.id)
+    db.prepare(`UPDATE amc_contract SET invoice_doc_id=? WHERE id=?`).run(inv.id, amcId)
+    writeAudit(db, userId, 'update', 'amc_contract', amcId, { invoiceDocId: amc.invoiceDocId }, { invoiceDocId: inv.id })
+    return inv
+  })()
+}
+
+/** Local outstanding read (payable − allocations − non-cancelled credit notes) —
+ *  mirrors repos-payments.outstandingOf. Task 7 exports outstandingPaise; this can
+ *  switch to it then, but does not depend on Task 7 to compile. */
+function outstandingOf(db: DB, docId: string): number {
+  const doc = getDocument(db, docId)
+  if (doc === null) return 0
+  const alloc = (db.prepare(
+    `SELECT COALESCE(SUM(amount_paise), 0) AS total FROM payment_allocation WHERE document_id=?`,
+  ).get(docId) as { total: number }).total
+  const credited = (db.prepare(
+    `SELECT COALESCE(SUM(payable_paise), 0) AS total FROM document
+     WHERE doc_type='CREDIT_NOTE' AND ref_doc_id=? AND status != 'cancelled'`,
+  ).get(docId) as { total: number }).total
+  return doc.payablePaise - alloc - credited
+}
+
+export function amcPaidStatus(db: DB, amc: AmcContract): 'paid' | 'unpaid' | 'unbilled' {
+  if (amc.legacyPaid === true) return 'paid'
+  if (amc.invoiceDocId === null) return 'unbilled'
+  return outstandingOf(db, amc.invoiceDocId) <= 0 ? 'paid' : 'unpaid'
+}
diff --git a/apps/hq/test/amc.test.ts b/apps/hq/test/amc.test.ts
new file mode 100644
index 0000000..9b8b805
--- /dev/null
+++ b/apps/hq/test/amc.test.ts
@@ -0,0 +1,39 @@
+import { describe, it, expect } from 'vitest'
+import { openDb } from '../src/db'
+import { seedIfEmpty } from '../src/seed'
+import { createClient } from '../src/repos-clients'
+import { recordPayment } from '../src/repos-payments'
+import {
+  createAmc, listAmc, generateAmcRenewalInvoice, amcPaidStatus, getAmc,
+} from '../src/repos-amc'
+
+function setup() {
+  const db = openDb(':memory:'); seedIfEmpty(db) // seeds company.state_code, GST18, AMC module
+  const c = createClient(db, 'u1', { name: 'Acme', stateCode: '32' })
+  return { db, c }
+}
+
+describe('amc contracts', () => {
+  it('creates, generates a renewal invoice, and derives paid from settlement', () => {
+    const { db, c } = setup()
+    const amc = createAmc(db, 'u1', {
+      clientId: c.id, coverage: 'On-site support', periodFrom: '2026-04-01', periodTo: '2027-03-31',
+      amountPaise: 20_000_00,
+    })
+    expect(listAmc(db, c.id)).toHaveLength(1)
+    expect(amcPaidStatus(db, getAmc(db, amc.id)!)).toBe('unbilled')
+    const inv = generateAmcRenewalInvoice(db, 'u1', amc.id)
+    expect(inv.docType).toBe('INVOICE')
+    expect(inv.payablePaise).toBe(23_600_00) // 20,000 + 18% GST intra-state
+    expect(amcPaidStatus(db, getAmc(db, amc.id)!)).toBe('unpaid')
+    recordPayment(db, 'u1', { clientId: c.id, receivedOn: '2026-07-10', mode: 'bank', amountPaise: 23_600_00 })
+    expect(amcPaidStatus(db, getAmc(db, amc.id)!)).toBe('paid')
+  })
+  it('honours the legacy_paid flag for imported contracts without an invoice', () => {
+    const { db, c } = setup()
+    const amc = createAmc(db, 'u1', {
+      clientId: c.id, periodFrom: '2025-04-01', periodTo: '2026-03-31', amountPaise: 10_000_00, legacyPaid: true,
+    })
+    expect(amcPaidStatus(db, getAmc(db, amc.id)!)).toBe('paid')
+  })
+})