diff --git a/products/03-alert-intelligence/.gitea/workflows/ci.yml b/products/03-alert-intelligence/.gitea/workflows/ci.yml
new file mode 100644
index 0000000..29eae3e
--- /dev/null
+++ b/products/03-alert-intelligence/.gitea/workflows/ci.yml
@@ -0,0 +1,27 @@
+name: CI
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+
+      - name: Install deps
+        run: npm ci
+        working-directory: products/03-alert-intelligence
+
+      - name: Type check
+        run: npx tsc --noEmit
+        working-directory: products/03-alert-intelligence
+
+      - name: Test
+        run: npm test
+        working-directory: products/03-alert-intelligence
diff --git a/products/03-alert-intelligence/Dockerfile b/products/03-alert-intelligence/Dockerfile
new file mode 100644
index 0000000..690069b
--- /dev/null
+++ b/products/03-alert-intelligence/Dockerfile
@@ -0,0 +1,14 @@
+FROM node:22-slim AS builder
+WORKDIR /app
+COPY package.json package-lock.json* ./
+RUN npm ci
+COPY . .
+RUN npm run build
+
+FROM node:22-slim
+WORKDIR /app
+COPY --from=builder /app/dist ./dist
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./
+EXPOSE 3000
+CMD ["node", "dist/index.js"]
diff --git a/products/03-alert-intelligence/fly.toml b/products/03-alert-intelligence/fly.toml
new file mode 100644
index 0000000..d247274
--- /dev/null
+++ b/products/03-alert-intelligence/fly.toml
@@ -0,0 +1,27 @@
+app = "dd0c-alert"
+primary_region = "iad"
+
+[build]
+  dockerfile = "Dockerfile"
+
+[env]
+  NODE_ENV = "production"
+  PORT = "3000"
+  LOG_LEVEL = "info"
+
+[http_service]
+  internal_port = 3000
+  force_https = true
+  auto_stop_machines = true
+  auto_start_machines = true
+  min_machines_running = 0
+
+  [http_service.concurrency]
+    type = "requests"
+    hard_limit = 200
+    soft_limit = 150
+
+[[vm]]
+  cpu_kind = "shared"
+  cpus = 1
+  memory_mb = 256
diff --git a/products/03-alert-intelligence/migrations/001_init.sql b/products/03-alert-intelligence/migrations/001_init.sql
new file mode 100644
index 0000000..83446cd
--- /dev/null
+++ b/products/03-alert-intelligence/migrations/001_init.sql
@@ -0,0 +1,90 @@
+-- dd0c/alert V1 schema — DynamoDB-style in PostgreSQL (Neon)
+
+CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
+
+-- Tenants
+CREATE TABLE tenants (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    name TEXT NOT NULL,
+    slug TEXT NOT NULL UNIQUE,
+    tier TEXT NOT NULL DEFAULT 'free' CHECK (tier IN ('free', 'pro')),
+    alert_count_month INT NOT NULL DEFAULT 0,
+    alert_count_reset_at TIMESTAMPTZ NOT NULL DEFAULT date_trunc('month', now()) + interval '1 month',
+    stripe_customer_id TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+-- Webhook secrets per provider per tenant
+CREATE TABLE webhook_secrets (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    tenant_id UUID NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+    provider TEXT NOT NULL CHECK (provider IN ('datadog', 'pagerduty', 'opsgenie', 'grafana', 'custom')),
+    secret TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    UNIQUE(tenant_id, provider)
+);
+
+-- Incidents (correlation output)
+CREATE TABLE incidents (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    tenant_id UUID NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+    incident_key TEXT NOT NULL,
+    fingerprint TEXT NOT NULL,
+    service TEXT,
+    title TEXT NOT NULL,
+    severity TEXT NOT NULL CHECK (severity IN ('critical', 'high', 'medium', 'low', 'info')),
+    status TEXT NOT NULL DEFAULT 'open' CHECK (status IN ('open', 'acknowledged', 'resolved', 'suppressed')),
+    alert_count INT NOT NULL DEFAULT 1,
+    first_alert_at TIMESTAMPTZ NOT NULL,
+    last_alert_at TIMESTAMPTZ NOT NULL,
+    resolved_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+CREATE INDEX idx_incidents_tenant ON incidents(tenant_id, status, created_at DESC);
+CREATE INDEX idx_incidents_fingerprint ON incidents(tenant_id, fingerprint);
+
+-- Alerts (raw, linked to incidents)
+CREATE TABLE alerts (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    tenant_id UUID NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+    incident_id UUID REFERENCES incidents(id) ON DELETE SET NULL,
+    source_provider TEXT NOT NULL,
+    source_id TEXT NOT NULL,
+    fingerprint TEXT NOT NULL,
+    title TEXT NOT NULL,
+    severity TEXT NOT NULL,
+    status TEXT NOT NULL,
+    service TEXT,
+    environment TEXT,
+    tags JSONB NOT NULL DEFAULT '{}',
+    raw_payload JSONB NOT NULL,
+    received_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+CREATE INDEX idx_alerts_tenant ON alerts(tenant_id, received_at DESC);
+CREATE INDEX idx_alerts_incident ON alerts(incident_id);
+
+-- Notification configs
+CREATE TABLE notification_configs (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    tenant_id UUID NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+    channel TEXT NOT NULL CHECK (channel IN ('slack', 'email', 'webhook')),
+    config JSONB NOT NULL DEFAULT '{}',
+    min_severity TEXT NOT NULL DEFAULT 'medium',
+    enabled BOOLEAN NOT NULL DEFAULT true,
+    UNIQUE(tenant_id, channel)
+);
+
+-- Free tier enforcement: 10K alerts/month, 7-day retention
+-- Pro tier: unlimited alerts, 90-day retention
+
+-- RLS
+ALTER TABLE incidents ENABLE ROW LEVEL SECURITY;
+ALTER TABLE alerts ENABLE ROW LEVEL SECURITY;
+ALTER TABLE notification_configs ENABLE ROW LEVEL SECURITY;
+
+CREATE POLICY tenant_iso_incidents ON incidents
+    USING (tenant_id::text = current_setting('app.tenant_id', true));
+CREATE POLICY tenant_iso_alerts ON alerts
+    USING (tenant_id::text = current_setting('app.tenant_id', true));
+CREATE POLICY tenant_iso_notif ON notification_configs
+    USING (tenant_id::text = current_setting('app.tenant_id', true));
diff --git a/products/03-alert-intelligence/package.json b/products/03-alert-intelligence/package.json
new file mode 100644
index 0000000..97f45b3
--- /dev/null
+++ b/products/03-alert-intelligence/package.json
@@ -0,0 +1,36 @@
+{
+  "name": "dd0c-alert",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "tsx watch src/index.ts",
+    "build": "tsc",
+    "start": "node dist/index.js",
+    "test": "vitest run",
+    "lint": "eslint src/ tests/"
+  },
+  "dependencies": {
+    "fastify": "^4.28.0",
+    "@fastify/cors": "^9.0.0",
+    "@fastify/helmet": "^11.1.0",
+    "pg": "^8.12.0",
+    "ioredis": "^5.4.0",
+    "zod": "^3.23.0",
+    "jsonwebtoken": "^9.0.2",
+    "pino": "^9.1.0",
+    "uuid": "^9.0.1",
+    "@aws-sdk/client-sqs": "^3.600.0",
+    "@aws-sdk/client-s3": "^3.600.0"
+  },
+  "devDependencies": {
+    "typescript": "^5.5.0",
+    "tsx": "^4.15.0",
+    "vitest": "^1.6.0",
+    "@types/node": "^20.14.0",
+    "@types/pg": "^8.11.0",
+    "@types/jsonwebtoken": "^9.0.6",
+    "@types/uuid": "^9.0.8",
+    "eslint": "^9.5.0"
+  }
+}
diff --git a/products/03-alert-intelligence/src/correlation/engine.ts b/products/03-alert-intelligence/src/correlation/engine.ts
new file mode 100644
index 0000000..902d725
--- /dev/null
+++ b/products/03-alert-intelligence/src/correlation/engine.ts
@@ -0,0 +1,165 @@
+import pino from 'pino';
+import type { CanonicalAlert } from '../ingestion/webhook.js';
+
+const logger = pino({ name: 'correlation' });
+
+// --- Interfaces ---
+
+export interface WindowStore {
+  getWindow(tenantId: string, fingerprint: string): Promise<CorrelationWindow | null>;
+  upsertWindow(tenantId: string, window: CorrelationWindow): Promise<void>;
+  closeWindow(tenantId: string, fingerprint: string): Promise<CorrelationWindow | null>;
+  getExpiredWindows(cutoffMs: number): Promise<CorrelationWindow[]>;
+}
+
+export interface Clock {
+  now(): number;
+}
+
+export class RealClock implements Clock {
+  now() { return Date.now(); }
+}
+
+export class FakeClock implements Clock {
+  private current: number;
+  constructor(start = Date.now()) { this.current = start; }
+  now() { return this.current; }
+  advanceBy(ms: number) { this.current += ms; }
+  set(ms: number) { this.current = ms; }
+}
+
+export interface CorrelationWindow {
+  fingerprint: string;
+  service: string;
+  alerts: CanonicalAlert[];
+  openedAt: number;
+  lastAlertAt: number;
+  incidentId?: string;
+  shipped: boolean;
+}
+
+export interface CorrelationResult {
+  incidentId: string;
+  action: 'new_incident' | 'attached_to_existing' | 'window_updated';
+  alertCount: number;
+}
+
+// --- Correlation Engine ---
+
+const DEFAULT_WINDOW_MS = 5 * 60 * 1000; // 5 minutes
+const LATE_ATTACH_MULTIPLIER = 2; // Attach late alerts up to 2x window
+
+export class CorrelationEngine {
+  private windowStore: WindowStore;
+  private clock: Clock;
+  private windowMs: number;
+
+  constructor(windowStore: WindowStore, clock: Clock = new RealClock(), windowMs = DEFAULT_WINDOW_MS) {
+    this.windowStore = windowStore;
+    this.clock = clock;
+    this.windowMs = windowMs;
+  }
+
+  async process(tenantId: string, alert: CanonicalAlert): Promise<CorrelationResult> {
+    const now = this.clock.now();
+    const existing = await this.windowStore.getWindow(tenantId, alert.fingerprint);
+
+    // Case 1: No existing window — create new
+    if (!existing) {
+      const window: CorrelationWindow = {
+        fingerprint: alert.fingerprint,
+        service: alert.service ?? 'unknown',
+        alerts: [alert],
+        openedAt: now,
+        lastAlertAt: now,
+        shipped: false,
+      };
+      await this.windowStore.upsertWindow(tenantId, window);
+      return { incidentId: '', action: 'window_updated', alertCount: 1 };
+    }
+
+    // Case 2: Window exists and is still open
+    if (!existing.shipped) {
+      existing.alerts.push(alert);
+      existing.lastAlertAt = now;
+      await this.windowStore.upsertWindow(tenantId, existing);
+      return {
+        incidentId: existing.incidentId ?? '',
+        action: 'window_updated',
+        alertCount: existing.alerts.length,
+      };
+    }
+
+    // Case 3: Window shipped (incident created) — late alert
+    const windowAge = now - existing.openedAt;
+
+    if (windowAge <= this.windowMs * LATE_ATTACH_MULTIPLIER) {
+      // Within 2x window — attach to existing incident
+      existing.alerts.push(alert);
+      existing.lastAlertAt = now;
+      await this.windowStore.upsertWindow(tenantId, existing);
+      return {
+        incidentId: existing.incidentId ?? '',
+        action: 'attached_to_existing',
+        alertCount: existing.alerts.length,
+      };
+    }
+
+    // Case 4: Very late alert (>2x window) — new incident
+    const newWindow: CorrelationWindow = {
+      fingerprint: alert.fingerprint,
+      service: alert.service ?? 'unknown',
+      alerts: [alert],
+      openedAt: now,
+      lastAlertAt: now,
+      shipped: false,
+    };
+    await this.windowStore.upsertWindow(tenantId, newWindow);
+    return { incidentId: '', action: 'new_incident', alertCount: 1 };
+  }
+
+  async flushWindows(tenantId: string): Promise<CorrelationWindow[]> {
+    const now = this.clock.now();
+    const cutoff = now - this.windowMs;
+    const expired = await this.windowStore.getExpiredWindows(cutoff);
+
+    const shipped: CorrelationWindow[] = [];
+    for (const window of expired) {
+      if (window.shipped) continue;
+      window.shipped = true;
+      window.incidentId = `inc_${crypto.randomUUID().slice(0, 8)}`;
+      await this.windowStore.upsertWindow(tenantId, window);
+      shipped.push(window);
+    }
+
+    return shipped;
+  }
+}
+
+// --- In-Memory Window Store (for testing) ---
+
+export class InMemoryWindowStore implements WindowStore {
+  private windows = new Map<string, CorrelationWindow>();
+
+  private key(tenantId: string, fingerprint: string) {
+    return `${tenantId}:${fingerprint}`;
+  }
+
+  async getWindow(tenantId: string, fingerprint: string) {
+    return this.windows.get(this.key(tenantId, fingerprint)) ?? null;
+  }
+
+  async upsertWindow(tenantId: string, window: CorrelationWindow) {
+    this.windows.set(this.key(tenantId, window.fingerprint), window);
+  }
+
+  async closeWindow(tenantId: string, fingerprint: string) {
+    const w = this.windows.get(this.key(tenantId, fingerprint));
+    if (w) this.windows.delete(this.key(tenantId, fingerprint));
+    return w ?? null;
+  }
+
+  async getExpiredWindows(cutoffMs: number) {
+    return Array.from(this.windows.values()).filter(w => w.lastAlertAt <= cutoffMs && !w.shipped);
+  }
+}
diff --git a/products/03-alert-intelligence/src/ingestion/webhook.ts b/products/03-alert-intelligence/src/ingestion/webhook.ts
new file mode 100644
index 0000000..a6dc48f
--- /dev/null
+++ b/products/03-alert-intelligence/src/ingestion/webhook.ts
@@ -0,0 +1,217 @@
+import { z } from 'zod';
+import crypto from 'node:crypto';
+import pino from 'pino';
+
+const logger = pino({ name: 'ingestion' });
+
+// --- Canonical Alert Schema ---
+
+export const canonicalAlertSchema = z.object({
+  sourceProvider: z.enum(['datadog', 'pagerduty', 'opsgenie', 'grafana', 'custom']),
+  sourceId: z.string(),
+  fingerprint: z.string(),
+  title: z.string(),
+  severity: z.enum(['critical', 'high', 'medium', 'low', 'info']),
+  status: z.enum(['firing', 'resolved']),
+  service: z.string().optional(),
+  environment: z.string().optional(),
+  tags: z.record(z.string()).default({}),
+  rawPayload: z.any(),
+  timestamp: z.number(), // Unix ms
+});
+
+export type CanonicalAlert = z.infer<typeof canonicalAlertSchema>;
+
+// --- HMAC Validation (BMad Must-Have: Replay Prevention) ---
+
+const MAX_TIMESTAMP_DRIFT_SECONDS = 300; // 5 minutes
+
+export interface HmacValidationResult {
+  valid: boolean;
+  error?: string;
+}
+
+export function validateDatadogHmac(
+  body: string,
+  signature: string | undefined,
+  timestamp: string | undefined,
+  secret: string,
+): HmacValidationResult {
+  if (!signature || !timestamp) {
+    return { valid: false, error: 'Missing signature or timestamp header' };
+  }
+
+  // Timestamp freshness check
+  const ts = parseInt(timestamp, 10);
+  const now = Math.floor(Date.now() / 1000);
+  if (Math.abs(now - ts) > MAX_TIMESTAMP_DRIFT_SECONDS) {
+    return { valid: false, error: 'stale timestamp' };
+  }
+
+  const expected = crypto
+    .createHmac('sha256', secret)
+    .update(timestamp + body)
+    .digest('hex');
+
+  if (!crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expected))) {
+    return { valid: false, error: 'Invalid signature' };
+  }
+
+  return { valid: true };
+}
+
+export function validatePagerdutyHmac(
+  body: string,
+  signature: string | undefined,
+  secret: string,
+): HmacValidationResult {
+  if (!signature) {
+    return { valid: false, error: 'Missing signature header' };
+  }
+
+  // PagerDuty v1 signatures include timestamp in the signature header
+  const parts = signature.split(',');
+  const tsPart = parts.find(p => p.startsWith('t='));
+  const sigPart = parts.find(p => p.startsWith('v1='));
+
+  if (!tsPart || !sigPart) {
+    return { valid: false, error: 'Malformed PagerDuty signature' };
+  }
+
+  const ts = parseInt(tsPart.slice(2), 10);
+  const now = Math.floor(Date.now() / 1000);
+  if (Math.abs(now - ts) > MAX_TIMESTAMP_DRIFT_SECONDS) {
+    return { valid: false, error: 'stale timestamp' };
+  }
+
+  const expected = crypto
+    .createHmac('sha256', secret)
+    .update(`${ts}.${body}`)
+    .digest('hex');
+
+  const sig = sigPart.slice(3);
+  if (!crypto.timingSafeEqual(Buffer.from(sig), Buffer.from(expected))) {
+    return { valid: false, error: 'Invalid signature' };
+  }
+
+  return { valid: true };
+}
+
+export function validateOpsgenieHmac(
+  body: string,
+  signature: string | undefined,
+  secret: string,
+): HmacValidationResult {
+  if (!signature) {
+    return { valid: false, error: 'Missing signature header' };
+  }
+
+  // OpsGenie: extract timestamp from payload body
+  let payload: any;
+  try {
+    payload = JSON.parse(body);
+  } catch {
+    return { valid: false, error: 'Invalid JSON body' };
+  }
+
+  const ts = payload?.timestamp;
+  if (ts) {
+    const tsSeconds = typeof ts === 'number' ? ts / 1000 : parseInt(ts, 10);
+    const now = Math.floor(Date.now() / 1000);
+    if (Math.abs(now - tsSeconds) > MAX_TIMESTAMP_DRIFT_SECONDS) {
+      return { valid: false, error: 'stale timestamp' };
+    }
+  }
+
+  const expected = crypto
+    .createHmac('sha256', secret)
+    .update(body)
+    .digest('hex');
+
+  if (!crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expected))) {
+    return { valid: false, error: 'Invalid signature' };
+  }
+
+  return { valid: true };
+}
+
+// --- Payload Normalizers ---
+
+export function normalizeDatadog(payload: any): CanonicalAlert {
+  return {
+    sourceProvider: 'datadog',
+    sourceId: payload.id ?? payload.alert_id ?? crypto.randomUUID(),
+    fingerprint: payload.aggregation_key ?? payload.alert_id ?? '',
+    title: payload.title ?? payload.msg_title ?? 'Datadog Alert',
+    severity: mapDatadogPriority(payload.priority),
+    status: payload.alert_transition === 'Recovered' ? 'resolved' : 'firing',
+    service: payload.tags?.service,
+    environment: payload.tags?.env,
+    tags: payload.tags ?? {},
+    rawPayload: payload,
+    timestamp: payload.date_happened ? payload.date_happened * 1000 : Date.now(),
+  };
+}
+
+export function normalizePagerduty(payload: any): CanonicalAlert {
+  const event = payload.event ?? payload;
+  const data = event.data ?? event.incident ?? {};
+  return {
+    sourceProvider: 'pagerduty',
+    sourceId: data.id ?? crypto.randomUUID(),
+    fingerprint: data.incident_key ?? data.id ?? '',
+    title: data.title ?? data.description ?? 'PagerDuty Incident',
+    severity: mapPagerdutyUrgency(data.urgency),
+    status: event.event_type?.includes('resolve') ? 'resolved' : 'firing',
+    service: data.service?.name,
+    environment: data.body?.details?.environment,
+    tags: {},
+    rawPayload: payload,
+    timestamp: data.created_at ? new Date(data.created_at).getTime() : Date.now(),
+  };
+}
+
+export function normalizeOpsgenie(payload: any): CanonicalAlert {
+  return {
+    sourceProvider: 'opsgenie',
+    sourceId: payload.alert?.alertId ?? crypto.randomUUID(),
+    fingerprint: payload.alert?.alias ?? payload.alert?.alertId ?? '',
+    title: payload.alert?.message ?? 'OpsGenie Alert',
+    severity: mapOpsgeniePriority(payload.alert?.priority),
+    status: payload.action === 'Close' ? 'resolved' : 'firing',
+    service: payload.alert?.tags?.find((t: string) => t.startsWith('service:'))?.slice(8),
+    tags: {},
+    rawPayload: payload,
+    timestamp: payload.alert?.createdAt ? new Date(payload.alert.createdAt).getTime() : Date.now(),
+  };
+}
+
+// --- Severity Mappers ---
+
+function mapDatadogPriority(p: string | undefined): CanonicalAlert['severity'] {
+  switch (p) {
+    case 'P1': return 'critical';
+    case 'P2': return 'high';
+    case 'P3': return 'medium';
+    case 'P4': return 'low';
+    default: return 'medium';
+  }
+}
+
+function mapPagerdutyUrgency(u: string | undefined): CanonicalAlert['severity'] {
+  switch (u) {
+    case 'high': return 'critical';
+    case 'low': return 'low';
+    default: return 'medium';
+  }
+}
+
+function mapOpsgeniePriority(p: string | undefined): CanonicalAlert['severity'] {
+  switch (p) {
+    case 'P1': return 'critical';
+    case 'P2': return 'high';
+    case 'P3': return 'medium';
+    case 'P4': case 'P5': return 'low';
+    default: return 'medium';
+  }
+}
diff --git a/products/03-alert-intelligence/tests/unit/correlation.test.ts b/products/03-alert-intelligence/tests/unit/correlation.test.ts
new file mode 100644
index 0000000..1f5c273
--- /dev/null
+++ b/products/03-alert-intelligence/tests/unit/correlation.test.ts
@@ -0,0 +1,106 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import {
+  CorrelationEngine,
+  InMemoryWindowStore,
+  FakeClock,
+} from '../../src/correlation/engine.js';
+import type { CanonicalAlert } from '../../src/ingestion/webhook.js';
+
+function makeAlert(overrides: Partial<CanonicalAlert> = {}): CanonicalAlert {
+  return {
+    sourceProvider: 'datadog',
+    sourceId: `alert-${Math.random().toString(36).slice(2)}`,
+    fingerprint: 'cpu-high',
+    title: 'CPU High',
+    severity: 'high',
+    status: 'firing',
+    service: 'auth',
+    tags: {},
+    rawPayload: {},
+    timestamp: Date.now(),
+    ...overrides,
+  };
+}
+
+describe('CorrelationEngine', () => {
+  let store: InMemoryWindowStore;
+  let clock: FakeClock;
+  let engine: CorrelationEngine;
+
+  beforeEach(() => {
+    store = new InMemoryWindowStore();
+    clock = new FakeClock(1000000);
+    engine = new CorrelationEngine(store, clock, 5 * 60 * 1000); // 5min window
+  });
+
+  it('creates a new window for first alert', async () => {
+    const result = await engine.process('t1', makeAlert());
+    expect(result.action).toBe('window_updated');
+    expect(result.alertCount).toBe(1);
+  });
+
+  it('groups alerts with same fingerprint into one window', async () => {
+    await engine.process('t1', makeAlert({ fingerprint: 'cpu-high' }));
+    const result = await engine.process('t1', makeAlert({ fingerprint: 'cpu-high' }));
+    expect(result.action).toBe('window_updated');
+    expect(result.alertCount).toBe(2);
+  });
+
+  it('keeps different fingerprints in separate windows', async () => {
+    await engine.process('t1', makeAlert({ fingerprint: 'cpu-high' }));
+    const result = await engine.process('t1', makeAlert({ fingerprint: 'disk-full' }));
+    expect(result.action).toBe('window_updated');
+    expect(result.alertCount).toBe(1); // New window, only 1 alert
+  });
+
+  it('late alert within 2x window attaches to existing incident', async () => {
+    // Alert 1 at T=0
+    await engine.process('t1', makeAlert());
+
+    // Flush at T=5min (window closes, incident created)
+    clock.advanceBy(5 * 60 * 1000);
+    const shipped = await engine.flushWindows('t1');
+    expect(shipped).toHaveLength(1);
+    expect(shipped[0].incidentId).toBeTruthy();
+
+    // Late alert at T=6min (within 2x window = 10min)
+    clock.advanceBy(1 * 60 * 1000);
+    const result = await engine.process('t1', makeAlert());
+    expect(result.action).toBe('attached_to_existing');
+    expect(result.incidentId).toBe(shipped[0].incidentId);
+  });
+
+  it('very late alert (>2x window) creates new incident', async () => {
+    await engine.process('t1', makeAlert());
+
+    clock.advanceBy(5 * 60 * 1000);
+    await engine.flushWindows('t1');
+
+    // 15 minutes later (3x window)
+    clock.advanceBy(10 * 60 * 1000);
+    const result = await engine.process('t1', makeAlert());
+    expect(result.action).toBe('new_incident');
+  });
+
+  it('flushWindows ships expired windows', async () => {
+    await engine.process('t1', makeAlert({ fingerprint: 'a' }));
+    await engine.process('t1', makeAlert({ fingerprint: 'b' }));
+
+    clock.advanceBy(6 * 60 * 1000); // Past 5min window
+    const shipped = await engine.flushWindows('t1');
+    expect(shipped).toHaveLength(2);
+    expect(shipped[0].incidentId).toBeTruthy();
+    expect(shipped[1].incidentId).toBeTruthy();
+  });
+
+  it('does not re-ship already shipped windows', async () => {
+    await engine.process('t1', makeAlert());
+    clock.advanceBy(6 * 60 * 1000);
+
+    const first = await engine.flushWindows('t1');
+    expect(first).toHaveLength(1);
+
+    const second = await engine.flushWindows('t1');
+    expect(second).toHaveLength(0);
+  });
+});
diff --git a/products/03-alert-intelligence/tests/unit/ingestion.test.ts b/products/03-alert-intelligence/tests/unit/ingestion.test.ts
new file mode 100644
index 0000000..6c906ce
--- /dev/null
+++ b/products/03-alert-intelligence/tests/unit/ingestion.test.ts
@@ -0,0 +1,138 @@
+import { describe, it, expect } from 'vitest';
+import {
+  validateDatadogHmac,
+  validatePagerdutyHmac,
+  validateOpsgenieHmac,
+  normalizeDatadog,
+  normalizePagerduty,
+  normalizeOpsgenie,
+} from '../../src/ingestion/webhook.js';
+import crypto from 'node:crypto';
+
+const SECRET = 'test-webhook-secret';
+
+describe('HMAC Validation', () => {
+  describe('Datadog', () => {
+    it('accepts valid signature with fresh timestamp', () => {
+      const body = '{"alert_id":"123"}';
+      const ts = Math.floor(Date.now() / 1000).toString();
+      const sig = crypto.createHmac('sha256', SECRET).update(ts + body).digest('hex');
+
+      const result = validateDatadogHmac(body, sig, ts, SECRET);
+      expect(result.valid).toBe(true);
+    });
+
+    it('rejects stale timestamp (>5 minutes)', () => {
+      const body = '{"alert_id":"123"}';
+      const ts = (Math.floor(Date.now() / 1000) - 301).toString();
+      const sig = crypto.createHmac('sha256', SECRET).update(ts + body).digest('hex');
+
+      const result = validateDatadogHmac(body, sig, ts, SECRET);
+      expect(result.valid).toBe(false);
+      expect(result.error).toContain('stale timestamp');
+    });
+
+    it('rejects missing signature', () => {
+      const result = validateDatadogHmac('{}', undefined, '123', SECRET);
+      expect(result.valid).toBe(false);
+    });
+
+    it('rejects invalid signature', () => {
+      const ts = Math.floor(Date.now() / 1000).toString();
+      const result = validateDatadogHmac('{}', 'bad-sig', ts, SECRET);
+      expect(result.valid).toBe(false);
+    });
+  });
+
+  describe('PagerDuty', () => {
+    it('rejects missing signature', () => {
+      const result = validatePagerdutyHmac('{}', undefined, SECRET);
+      expect(result.valid).toBe(false);
+    });
+
+    it('rejects malformed signature', () => {
+      const result = validatePagerdutyHmac('{}', 'garbage', SECRET);
+      expect(result.valid).toBe(false);
+    });
+  });
+
+  describe('OpsGenie', () => {
+    it('rejects stale timestamp from payload body', () => {
+      const staleTs = Date.now() - 6 * 60 * 1000; // 6 minutes ago
+      const body = JSON.stringify({ alert: { alertId: '1' }, timestamp: staleTs });
+      const sig = crypto.createHmac('sha256', SECRET).update(body).digest('hex');
+
+      const result = validateOpsgenieHmac(body, sig, SECRET);
+      expect(result.valid).toBe(false);
+      expect(result.error).toContain('stale timestamp');
+    });
+
+    it('accepts fresh payload', () => {
+      const body = JSON.stringify({ alert: { alertId: '1' }, timestamp: Date.now() });
+      const sig = crypto.createHmac('sha256', SECRET).update(body).digest('hex');
+
+      const result = validateOpsgenieHmac(body, sig, SECRET);
+      expect(result.valid).toBe(true);
+    });
+  });
+});
+
+describe('Payload Normalizers', () => {
+  it('normalizes Datadog payload', () => {
+    const alert = normalizeDatadog({
+      alert_id: 'dd-123',
+      title: 'High CPU',
+      priority: 'P1',
+      alert_transition: 'Triggered',
+      tags: { service: 'auth', env: 'prod' },
+      date_happened: 1709251200,
+    });
+    expect(alert.sourceProvider).toBe('datadog');
+    expect(alert.severity).toBe('critical');
+    expect(alert.status).toBe('firing');
+    expect(alert.service).toBe('auth');
+  });
+
+  it('normalizes PagerDuty payload', () => {
+    const alert = normalizePagerduty({
+      event: {
+        event_type: 'incident.triggered',
+        data: {
+          id: 'pd-456',
+          title: 'Disk Full',
+          urgency: 'high',
+          service: { name: 'storage' },
+          created_at: '2026-03-01T00:00:00Z',
+        },
+      },
+    });
+    expect(alert.sourceProvider).toBe('pagerduty');
+    expect(alert.severity).toBe('critical');
+    expect(alert.service).toBe('storage');
+  });
+
+  it('normalizes OpsGenie payload', () => {
+    const alert = normalizeOpsgenie({
+      action: 'Create',
+      alert: {
+        alertId: 'og-789',
+        message: 'Memory Leak',
+        priority: 'P2',
+        tags: ['service:api'],
+      },
+    });
+    expect(alert.sourceProvider).toBe('opsgenie');
+    expect(alert.severity).toBe('high');
+    expect(alert.status).toBe('firing');
+  });
+
+  it('maps Datadog Recovered to resolved', () => {
+    const alert = normalizeDatadog({ alert_transition: 'Recovered' });
+    expect(alert.status).toBe('resolved');
+  });
+
+  it('maps OpsGenie Close to resolved', () => {
+    const alert = normalizeOpsgenie({ action: 'Close', alert: {} });
+    expect(alert.status).toBe('resolved');
+  });
+});
diff --git a/products/03-alert-intelligence/tsconfig.json b/products/03-alert-intelligence/tsconfig.json
new file mode 100644
index 0000000..47b40ee
--- /dev/null
+++ b/products/03-alert-intelligence/tsconfig.json
@@ -0,0 +1,18 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "outDir": "dist",
+    "rootDir": "src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "declaration": true,
+    "sourceMap": true
+  },
+  "include": ["src"],
+  "exclude": ["node_modules", "dist", "tests"]
+}