diff --git a/apps/hq/src/api.ts b/apps/hq/src/api.ts
index 496d4bd..4be5b96 100644
--- a/apps/hq/src/api.ts
+++ b/apps/hq/src/api.ts
@@ -27,6 +27,10 @@ import {
   amcPaidStatus, createAmc, deactivateAmc, generateAmcRenewalInvoice, getAmc, listAmc,
   updateAmc, type AmcPatch, type CreateAmcInput,
 } from './repos-amc'
+import {
+  createInteraction, createInteractionType, getInteraction, listInteractions,
+  listInteractionTypes, updateInteraction, type CreateInteractionInput, type InteractionPatch,
+} from './repos-interactions'
 import { documentHtml } from './templates'
 import { renderPdf } from './pdf'
 import { emailStatus } from './repos-email'
@@ -372,6 +376,45 @@ export function apiRouter(db: DB, gmailDeps?: Partial<GmailDeps>): Router {
     }
   })
 
+  // ---------- interactions ----------
+  r.get('/interaction-types', requireAuth, (_req, res) => {
+    res.json({ ok: true, types: listInteractionTypes(db) })
+  })
+  r.post('/interaction-types', requireAuth, requireOwner, (req, res) => {
+    try {
+      const type = createInteractionType(db, staffId(res), req.body as { code: string; label: string })
+      res.json({ ok: true, type })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
+  r.get('/clients/:id/interactions', 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 }
+    res.json({ ok: true, interactions: listInteractions(db, id) })
+  })
+  r.post('/clients/:id/interactions', 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 }
+    try {
+      const interaction = createInteraction(db, staffId(res), {
+        ...(req.body as Omit<CreateInteractionInput, 'clientId'>), clientId: id,
+      })
+      res.json({ ok: true, interaction })
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
+    }
+  })
+  r.patch('/interactions/:id', requireAuth, (req, res) => {
+    const id = String(req.params['id'] ?? '')
+    if (getInteraction(db, id) === null) { res.status(404).json({ ok: false, error: 'Interaction not found' }); return }
+    try {
+      res.json({ ok: true, interaction: updateInteraction(db, staffId(res), id, req.body as InteractionPatch) })
+    } 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-interactions.ts b/apps/hq/src/repos-interactions.ts
new file mode 100644
index 0000000..db643f7
--- /dev/null
+++ b/apps/hq/src/repos-interactions.ts
@@ -0,0 +1,107 @@
+import { uuidv7 } from '@sims/domain'
+import { writeAudit } from './audit'
+import type { DB } from './db'
+import { getClient } from './repos-clients'
+
+/** Interaction log — the "memories into the system" table (D12 plain-repo pattern). */
+
+export interface InteractionType { code: string; label: string }
+
+export function listInteractionTypes(db: DB): InteractionType[] {
+  return db.prepare(`SELECT code, label FROM interaction_type ORDER BY label`).all() as InteractionType[]
+}
+
+export function createInteractionType(db: DB, userId: string, input: { code: string; label: string }): InteractionType {
+  if (input.code.trim() === '' || input.label.trim() === '') throw new Error('code and label are required')
+  db.prepare(`INSERT INTO interaction_type (code, label) VALUES (?, ?)`).run(input.code.trim(), input.label.trim())
+  writeAudit(db, userId, 'create', 'interaction_type', input.code, undefined, input)
+  return { code: input.code.trim(), label: input.label.trim() }
+}
+
+export type Outcome = 'positive' | 'neutral' | 'negative'
+
+export interface Interaction {
+  id: string; clientId: string; typeCode: string; onDate: string; staffId: string
+  notes: string; outcome: Outcome | null; followUpOn: string | null; createdAt: string
+}
+
+interface InteractionRow {
+  id: string; client_id: string; type_code: string; on_date: string; staff_id: string
+  notes: string; outcome: string | null; follow_up_on: string | null; created_at: string
+}
+
+function toInteraction(r: InteractionRow): Interaction {
+  return {
+    id: r.id, clientId: r.client_id, typeCode: r.type_code, onDate: r.on_date, staffId: r.staff_id,
+    notes: r.notes, outcome: r.outcome as Outcome | null, followUpOn: r.follow_up_on, createdAt: r.created_at,
+  }
+}
+
+export function getInteraction(db: DB, id: string): Interaction | null {
+  const row = db.prepare(`SELECT * FROM interaction WHERE id=?`).get(id) as InteractionRow | undefined
+  return row === undefined ? null : toInteraction(row)
+}
+
+export function listInteractions(db: DB, clientId: string): Interaction[] {
+  const rows = db.prepare(
+    `SELECT * FROM interaction WHERE client_id=? ORDER BY on_date DESC, id DESC`,
+  ).all(clientId) as InteractionRow[]
+  return rows.map(toInteraction)
+}
+
+export interface CreateInteractionInput {
+  clientId: string; typeCode: string; onDate: string
+  notes?: string; outcome?: Outcome; followUpOn?: string | null
+}
+
+const OUTCOMES: Outcome[] = ['positive', 'neutral', 'negative']
+
+export function createInteraction(db: DB, userId: string, input: CreateInteractionInput): Interaction {
+  if (getClient(db, input.clientId) === null) throw new Error('Client not found')
+  const type = db.prepare(`SELECT code FROM interaction_type WHERE code=?`).get(input.typeCode)
+  if (type === undefined) throw new Error(`Unknown interaction type: ${input.typeCode}`)
+  if (input.outcome !== undefined && !OUTCOMES.includes(input.outcome)) throw new Error(`Unknown outcome: ${input.outcome}`)
+  const id = uuidv7()
+  db.prepare(
+    `INSERT INTO interaction (id, client_id, type_code, on_date, staff_id, notes, outcome, follow_up_on, created_at)
+     VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+  ).run(
+    id, input.clientId, input.typeCode, input.onDate, userId, input.notes ?? '',
+    input.outcome ?? null, input.followUpOn ?? null, new Date().toISOString(),
+  )
+  const interaction = getInteraction(db, id)!
+  writeAudit(db, userId, 'create', 'interaction', id, undefined, interaction)
+  return interaction
+}
+
+export interface InteractionPatch { notes?: string; outcome?: Outcome | null; followUpOn?: string | null }
+
+export function updateInteraction(db: DB, userId: string, id: string, patch: InteractionPatch): Interaction {
+  const before = getInteraction(db, id)
+  if (before === null) throw new Error('Interaction not found')
+  if (patch.outcome !== undefined && patch.outcome !== null && !OUTCOMES.includes(patch.outcome)) {
+    throw new Error(`Unknown outcome: ${patch.outcome}`)
+  }
+  const sets: string[] = []
+  const args: unknown[] = []
+  if (patch.notes !== undefined) { sets.push('notes=?'); args.push(patch.notes) }
+  if (patch.outcome !== undefined) { sets.push('outcome=?'); args.push(patch.outcome) }
+  if (patch.followUpOn !== undefined) { sets.push('follow_up_on=?'); args.push(patch.followUpOn) }
+  if (sets.length > 0) {
+    args.push(id)
+    db.prepare(`UPDATE interaction SET ${sets.join(', ')} WHERE id=?`).run(...args)
+  }
+  const after = getInteraction(db, id)!
+  writeAudit(db, userId, 'update', 'interaction', id, before, after)
+  return after
+}
+
+/** Interactions with a follow-up date on or before the given date — the follow-ups queue. */
+export function listOpenFollowUps(db: DB, onOrBefore: string): (Interaction & { clientName: string })[] {
+  const rows = db.prepare(
+    `SELECT i.*, c.name AS client_name FROM interaction i JOIN client c ON c.id = i.client_id
+     WHERE i.follow_up_on IS NOT NULL AND i.follow_up_on <= ?
+     ORDER BY i.follow_up_on DESC, i.id DESC`,
+  ).all(onOrBefore) as (InteractionRow & { client_name: string })[]
+  return rows.map((r) => ({ ...toInteraction(r), clientName: r.client_name }))
+}
diff --git a/apps/hq/test/interactions.test.ts b/apps/hq/test/interactions.test.ts
new file mode 100644
index 0000000..cd08923
--- /dev/null
+++ b/apps/hq/test/interactions.test.ts
@@ -0,0 +1,30 @@
+import { describe, it, expect } from 'vitest'
+import { openDb } from '../src/db'
+import { seedIfEmpty } from '../src/seed'
+import { createClient } from '../src/repos-clients'
+import {
+  createInteraction, listInteractions, listInteractionTypes, listOpenFollowUps, updateInteraction,
+} from '../src/repos-interactions'
+
+describe('interactions', () => {
+  it('logs a typed interaction, updates outcome, and surfaces due follow-ups', () => {
+    const db = openDb(':memory:'); seedIfEmpty(db)
+    expect(listInteractionTypes(db).length).toBeGreaterThanOrEqual(7)
+    const c = createClient(db, 'u1', { name: 'Acme', stateCode: '32' })
+    const i = createInteraction(db, 'u1', {
+      clientId: c.id, typeCode: 'site_visit', onDate: '2026-07-01',
+      notes: 'Installed POS; owner wants training', followUpOn: '2026-07-08',
+    })
+    expect(listInteractions(db, c.id)).toHaveLength(1)
+    const up = updateInteraction(db, 'u1', i.id, { outcome: 'positive' })
+    expect(up.outcome).toBe('positive')
+    expect(listOpenFollowUps(db, '2026-07-10').map((f) => f.id)).toContain(i.id)
+    expect(listOpenFollowUps(db, '2026-07-05')).toHaveLength(0) // not yet due
+  })
+  it('rejects an unknown interaction type', () => {
+    const db = openDb(':memory:'); seedIfEmpty(db)
+    const c = createClient(db, 'u1', { name: 'X', stateCode: '32' })
+    expect(() => createInteraction(db, 'u1', { clientId: c.id, typeCode: 'telepathy', onDate: '2026-07-01' }))
+      .toThrow(/type/i)
+  })
+})