diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d61c830b1..d8c24bf34 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -472,6 +472,58 @@ jobs:
             echo "::warning::Potentially vulnerable axios version detected"
           fi
 
+  # ===========================================
+  # Auth flow integration test
+  # ===========================================
+  # Spins up postgres + redis + mailpit + mana-auth + mana-notify via
+  # docker-compose.test.yml and runs tests/integration/auth-flow.test.ts.
+  # Catches register/verify/login/JWT/encryption-vault regressions before
+  # they can be merged. Required check — never bypass.
+
+  auth-integration:
+    name: Auth flow integration test
+    runs-on: ubuntu-latest
+    if: github.event_name == 'pull_request'
+    timeout-minutes: 15
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v2
+        with:
+          version: ${{ env.PNPM_VERSION }}
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ env.NODE_VERSION }}
+          cache: 'pnpm'
+
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run auth flow integration test
+        run: ./scripts/run-integration-tests.sh
+
+      - name: Dump test stack logs on failure
+        if: failure()
+        run: |
+          echo "::group::mana-auth logs"
+          docker logs mana-test-mana-auth 2>&1 | tail -200 || true
+          echo "::endgroup::"
+          echo "::group::mana-notify logs"
+          docker logs mana-test-mana-notify 2>&1 | tail -200 || true
+          echo "::endgroup::"
+          echo "::group::mailpit messages"
+          curl -s http://localhost:8026/api/v1/messages | head -100 || true
+          echo "::endgroup::"
+
   # ===========================================
   # Build Docker images - only changed services
   # ===========================================
diff --git a/docker-compose.dev.yml b/docker-compose.dev.yml
index 7525d975d..ffbc52c7e 100644
--- a/docker-compose.dev.yml
+++ b/docker-compose.dev.yml
@@ -44,6 +44,28 @@ services:
       timeout: 5s
       retries: 5
 
+  # Mailpit — fake SMTP server for local development.
+  # Catches every outbound mail and exposes them via web UI + REST API.
+  # Point any service that sends email at SMTP_HOST=mailpit, SMTP_PORT=1025
+  # and inspect what came in at http://localhost:8025.
+  mailpit:
+    image: axllent/mailpit:latest
+    container_name: mana-mailpit
+    restart: unless-stopped
+    environment:
+      MP_SMTP_AUTH_ACCEPT_ANY: "1"
+      MP_SMTP_AUTH_ALLOW_INSECURE: "1"
+    ports:
+      - "1025:1025"   # SMTP
+      - "8025:8025"   # Web UI + REST API
+    networks:
+      - mana-network
+    healthcheck:
+      test: ["CMD", "wget", "-q", "--spider", "http://localhost:8025/api/v1/info"]
+      interval: 10s
+      timeout: 5s
+      retries: 3
+
   # MinIO Object Storage (S3-compatible)
   minio:
     image: minio/minio:latest
diff --git a/docker-compose.test.yml b/docker-compose.test.yml
new file mode 100644
index 000000000..6301c8024
--- /dev/null
+++ b/docker-compose.test.yml
@@ -0,0 +1,166 @@
+# Integration test stack for the auth/credentials/encryption-vault flow.
+#
+# Spins up the minimum stack needed to register, verify, log in, and
+# exercise the encryption-vault: postgres + redis + mailpit (fake SMTP)
+# + mana-auth + mana-notify. No mana-credits, mana-sync, mana-media etc.
+# — those are not on the auth-flow critical path and would just slow
+# down the build.
+#
+# Ports are offset from docker-compose.dev.yml so this stack can run
+# alongside a normal dev environment. Everything is bound to 127.0.0.1
+# so it's only reachable from the same machine.
+#
+# Usage:
+#   ./scripts/run-integration-tests.sh
+#
+# Or manually:
+#   docker compose -f docker-compose.test.yml up -d --build
+#   docker compose -f docker-compose.test.yml down -v
+#
+# The compose project is namespaced as `mana-test` so the containers,
+# network and volumes don't collide with the dev stack.
+name: mana-test
+
+services:
+  postgres:
+    image: postgres:16-alpine
+    container_name: mana-test-postgres
+    environment:
+      POSTGRES_DB: mana_platform
+      POSTGRES_USER: mana
+      POSTGRES_PASSWORD: testpassword
+    volumes:
+      - ./docker/init-db:/docker-entrypoint-initdb.d:ro
+    ports:
+      - "127.0.0.1:5443:5432"
+    networks:
+      - mana-test
+    healthcheck:
+      # pg_isready alone reports healthy while the docker-entrypoint init
+      # scripts are still running on a unix socket — TCP connections from
+      # other containers then race-fail with "connection refused". Run a
+      # real query against the actual platform DB so we only flip healthy
+      # once postgres is genuinely accepting external TCP traffic.
+      test: ["CMD-SHELL", "PGPASSWORD=testpassword psql -h localhost -U mana -d mana_platform -tAc 'SELECT 1' >/dev/null"]
+      interval: 2s
+      timeout: 3s
+      retries: 30
+      start_period: 5s
+
+  redis:
+    image: redis:7-alpine
+    container_name: mana-test-redis
+    command: redis-server --requirepass testpassword --maxmemory 64mb
+    ports:
+      - "127.0.0.1:6390:6379"
+    networks:
+      - mana-test
+    healthcheck:
+      test: ["CMD", "redis-cli", "-a", "testpassword", "ping"]
+      interval: 2s
+      timeout: 3s
+      retries: 10
+
+  # Fake SMTP server. Captures every outbound email and exposes them
+  # via a REST API on :8025 (also a web UI on the same port). Tests
+  # poll the API to find the verification email.
+  mailpit:
+    image: axllent/mailpit:latest
+    container_name: mana-test-mailpit
+    environment:
+      MP_SMTP_AUTH_ACCEPT_ANY: "1"
+      MP_SMTP_AUTH_ALLOW_INSECURE: "1"
+    ports:
+      - "127.0.0.1:1026:1025"  # SMTP
+      - "127.0.0.1:8026:8025"  # HTTP API + Web UI
+    networks:
+      - mana-test
+    healthcheck:
+      test: ["CMD", "wget", "-q", "--spider", "http://localhost:8025/api/v1/info"]
+      interval: 2s
+      timeout: 3s
+      retries: 10
+
+  mana-auth:
+    build:
+      context: ./services/mana-auth
+      dockerfile: Dockerfile
+    container_name: mana-test-mana-auth
+    environment:
+      NODE_ENV: production    # exercise the prod KEK validation path
+      PORT: 3001
+      DATABASE_URL: postgresql://mana:testpassword@postgres:5432/mana_platform
+      # BASE_URL must be reachable from INSIDE the container — the validate
+      # endpoint fetches its own JWKS via this URL, and the JWT iss claim
+      # uses it. The test rewrites email verify URLs from `mana-auth:3001`
+      # to the host-bound port before following them.
+      BASE_URL: http://mana-auth:3001
+      COOKIE_DOMAIN: localhost
+      BETTER_AUTH_SECRET: test-secret-not-for-production
+      MANA_AUTH_KEK: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=  # 32 zero bytes, test only
+      MANA_NOTIFY_URL: http://mana-notify:3013
+      MANA_SERVICE_KEY: test-service-key
+      MANA_CREDITS_URL: http://localhost:9   # unreachable, .catch() swallows it
+      MANA_SUBSCRIPTIONS_URL: http://localhost:9
+      CORS_ORIGINS: http://localhost:5173,http://localhost:3091
+    depends_on:
+      postgres:
+        condition: service_healthy
+    ports:
+      - "127.0.0.1:3091:3001"
+    networks:
+      - mana-test
+    healthcheck:
+      test: ["CMD", "bun", "-e", "fetch('http://127.0.0.1:3001/health').then(r=>process.exit(r.ok?0:1)).catch(()=>process.exit(1))"]
+      interval: 3s
+      timeout: 3s
+      retries: 20
+      start_period: 10s
+
+  mana-notify:
+    build:
+      context: .
+      dockerfile: services/mana-notify/Dockerfile
+    container_name: mana-test-mana-notify
+    # mana-notify pings the database once at startup and exits on
+    # failure. If postgres is mid-restart at exactly that millisecond
+    # we want compose to bring it back up rather than declare the
+    # whole stack dead.
+    restart: on-failure:5
+    environment:
+      PORT: 3013
+      DATABASE_URL: postgresql://mana:testpassword@postgres:5432/mana_platform?sslmode=disable
+      REDIS_HOST: redis
+      REDIS_PORT: 6379
+      REDIS_PASSWORD: testpassword
+      SERVICE_KEY: test-service-key
+      MANA_AUTH_URL: http://mana-auth:3001
+      SMTP_HOST: mailpit
+      SMTP_PORT: 1025
+      SMTP_USER: test
+      SMTP_PASSWORD: test
+      SMTP_FROM: "Mana Test <noreply@test.local>"
+      SMTP_INSECURE_TLS: "true"
+    depends_on:
+      postgres:
+        condition: service_healthy
+      redis:
+        condition: service_healthy
+      mailpit:
+        condition: service_healthy
+    ports:
+      - "127.0.0.1:3092:3013"
+    networks:
+      - mana-test
+    healthcheck:
+      # Override the Dockerfile's port-3040 healthcheck — mana-notify
+      # actually binds to the PORT env var (3013 here).
+      test: ["CMD", "wget", "-q", "--spider", "http://localhost:3013/health"]
+      interval: 3s
+      timeout: 3s
+      retries: 20
+      start_period: 5s
+
+networks:
+  mana-test:
+    driver: bridge
diff --git a/scripts/run-integration-tests.sh b/scripts/run-integration-tests.sh
new file mode 100755
index 000000000..c42aea5c8
--- /dev/null
+++ b/scripts/run-integration-tests.sh
@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+#
+# Run the auth-flow integration test against a fresh docker-compose.test.yml stack.
+#
+# Usage:
+#   ./scripts/run-integration-tests.sh           # build, run, tear down
+#   KEEP_STACK=1 ./scripts/run-integration-tests.sh  # leave stack up after run
+#
+# In CI, just call this. Locally, useful for both quick reruns and the
+# "wait what does Mailpit look like" debugging step (set KEEP_STACK=1 then
+# open http://127.0.0.1:8026).
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+COMPOSE_FILE="$REPO_ROOT/docker-compose.test.yml"
+TEST_DIR="$REPO_ROOT/tests/integration"
+
+# Pick a docker binary that's actually on PATH. macOS layouts vary.
+if command -v docker >/dev/null 2>&1; then
+	DOCKER=docker
+elif [ -x /opt/homebrew/bin/docker ]; then
+	DOCKER=/opt/homebrew/bin/docker
+elif [ -x /usr/local/bin/docker ]; then
+	DOCKER=/usr/local/bin/docker
+else
+	echo "error: docker not found in PATH" >&2
+	exit 1
+fi
+
+cd "$REPO_ROOT"
+
+cleanup() {
+	if [ "${KEEP_STACK:-0}" = "1" ]; then
+		echo
+		echo "==> KEEP_STACK=1, leaving the test stack up."
+		echo "    Mailpit UI:  http://127.0.0.1:8026"
+		echo "    mana-auth:   http://127.0.0.1:3091"
+		echo "    Postgres:    psql postgresql://mana:testpassword@localhost:5443/mana_platform"
+		echo "    Tear down:   $DOCKER compose -f $COMPOSE_FILE down -v"
+		return
+	fi
+	echo
+	echo "==> Tearing down test stack"
+	$DOCKER compose -f "$COMPOSE_FILE" down -v --remove-orphans >/dev/null 2>&1 || true
+}
+trap cleanup EXIT
+
+echo "==> Building & starting test stack"
+$DOCKER compose -f "$COMPOSE_FILE" up -d --build --wait
+
+echo "==> Pushing mana-auth Drizzle schema into test postgres"
+DATABASE_URL="postgresql://mana:testpassword@localhost:5443/mana_platform" \
+	pnpm --filter @mana/auth db:push --force >/dev/null
+
+echo "==> Applying encryption-vault SQL migrations (002, 003)"
+$DOCKER cp "$REPO_ROOT/services/mana-auth/sql/002_encryption_vaults.sql" \
+	mana-test-postgres:/tmp/002.sql
+$DOCKER cp "$REPO_ROOT/services/mana-auth/sql/003_recovery_wrap.sql" \
+	mana-test-postgres:/tmp/003.sql
+$DOCKER exec mana-test-postgres psql -U mana -d mana_platform -f /tmp/002.sql >/dev/null
+$DOCKER exec mana-test-postgres psql -U mana -d mana_platform -f /tmp/003.sql >/dev/null
+
+echo "==> Restarting mana-auth so it picks up the freshly-created tables"
+# mana-auth's connection pool might have been opened against an empty DB. A
+# quick restart guarantees a clean cache + schema view.
+$DOCKER compose -f "$COMPOSE_FILE" restart mana-auth >/dev/null
+$DOCKER compose -f "$COMPOSE_FILE" up -d --wait mana-auth
+
+echo "==> Running auth-flow integration test"
+cd "$TEST_DIR"
+bun test auth-flow.test.ts
+
+echo
+echo "✅ integration tests passed"
diff --git a/tests/integration/README.md b/tests/integration/README.md
new file mode 100644
index 000000000..41e1be3bd
--- /dev/null
+++ b/tests/integration/README.md
@@ -0,0 +1,50 @@
+# Integration tests
+
+End-to-end tests that exercise real services against real Postgres + Redis + a fake SMTP server (Mailpit), via `docker-compose.test.yml`.
+
+## What's covered
+
+| File | Flow under test |
+|------|----------|
+| `auth-flow.test.ts` | register → email verification (via Mailpit) → login → JWT validation → `/me/data` → encryption vault init/key → logout |
+
+## Running locally
+
+```bash
+./scripts/run-integration-tests.sh
+```
+
+That script:
+
+1. Brings up `docker-compose.test.yml` (postgres, redis, mailpit, mana-auth, mana-notify) on isolated ports (`5443`, `6390`, `8026`, `3091`, `3092`)
+2. Waits for everything to be healthy
+3. Pushes the `@mana/auth` Drizzle schema into the test database
+4. Applies the encryption-vault SQL migrations (`002_encryption_vaults.sql`, `003_recovery_wrap.sql`)
+5. Runs `bun test auth-flow.test.ts` from this directory
+6. Tears the stack down on exit (success or failure)
+
+The whole thing runs in well under a minute on a warm Docker cache.
+
+## Mailpit web UI
+
+While the stack is up you can also browse incoming mail manually at <http://127.0.0.1:8026>.
+
+## Why this exists
+
+Bugs caught by this test the first time it ran:
+
+- `services/mana-auth` imported `nanoid` but didn't declare it in its `package.json` → `Cannot find package 'nanoid'` at startup, register endpoint 500'd. Local `pnpm install` resolved it transitively via `postcss → nanoid@3.3.11`, an isolated container build couldn't.
+- `MANA_AUTH_KEK` was never passed through to the mana-auth container in `docker-compose.macmini.yml`, so the prod service hard-failed at startup with `MANA_AUTH_KEK env var is required in production`.
+- The encryption-vault SQL migrations (`002`, `003`) had never been applied to prod Postgres, so any vault endpoint 500'd with `relation "auth.encryption_vaults" does not exist`.
+- `/api/v1/auth/login` minted a JWT by reconstructing the session cookie under the wrong name (`mana.session_token` instead of `__Secure-mana.session_token`), so the JWT-mint silently fell through and clients got `accessToken: undefined`.
+- mana-notify SMTP credentials were misconfigured against Stalwart, so no verification email actually went out — the failure was buried in mana-notify worker logs and the auth flow appeared to "work" only because the user could be flipped to verified by other means.
+
+Each of those would have been a single red `bun test` run instead of a multi-hour debugging session.
+
+## Adding more flows
+
+Drop another `<name>.test.ts` next to `auth-flow.test.ts` and update `package.json` to include it. Use the same helpers (`postJson`, `waitForMail`, `pgExec`) — they're free to copy.
+
+## CI
+
+The same script runs in `.github/workflows/ci.yml` as a required PR check. Don't bypass it.
diff --git a/tests/integration/auth-flow.test.ts b/tests/integration/auth-flow.test.ts
new file mode 100644
index 000000000..ee73a4311
--- /dev/null
+++ b/tests/integration/auth-flow.test.ts
@@ -0,0 +1,237 @@
+/**
+ * End-to-end auth flow integration test.
+ *
+ * Spins up nothing on its own — assumes the docker-compose.test.yml stack
+ * is already running. Run via `./scripts/run-integration-tests.sh` which
+ * brings up the stack, applies the encryption-vault SQL migrations, runs
+ * this test, then tears the stack down.
+ *
+ * What this test covers, in order:
+ *
+ *   1. POST /api/v1/auth/register                          → user created
+ *   2. mana-auth → mana-notify → mailpit                   → email arrives
+ *   3. Extract verify URL from email body
+ *   4. GET <verify URL>                                    → email_verified
+ *   5. POST /api/v1/auth/login                             → JWT minted
+ *   6. POST /api/v1/auth/validate(JWT)                     → claims valid
+ *   7. GET  /api/v1/me/data                                → user summary
+ *   8. POST /api/v1/me/encryption-vault/init               → master key
+ *   9. GET  /api/v1/me/encryption-vault/key                → unwrap roundtrip
+ *  10. POST /api/v1/auth/logout                            → success
+ *  11. (cleanup) DELETE the test user from postgres
+ *
+ * Every regression we hit on 2026-04-08 would have been caught here:
+ *   - missing nanoid dep                → step 1 → 500
+ *   - missing MANA_AUTH_KEK             → mana-auth never starts
+ *   - missing encryption_vaults table   → step 8 → 500
+ *   - wrong cookie name in /login       → step 5 → no accessToken
+ *   - mana-notify SMTP auth fails       → step 2 → mailpit times out
+ */
+
+import { test, expect, beforeAll, afterAll } from 'bun:test';
+
+const AUTH_URL = process.env.AUTH_URL ?? 'http://localhost:3091';
+const MAILPIT_URL = process.env.MAILPIT_URL ?? 'http://localhost:8026';
+
+// Postgres connection (for the cleanup step). Reads the env that
+// run-integration-tests.sh sets, falls back to the test stack defaults.
+const PG_DSN =
+	process.env.TEST_DATABASE_URL ?? 'postgresql://mana:testpassword@localhost:5443/mana_platform';
+
+// Generated per test run so reruns don't collide.
+const TEST_EMAIL = `auth-flow-${Date.now()}@manatest.local`;
+const TEST_PASSWORD = 'TestPassword123!';
+const TEST_NAME = 'Auth Flow';
+
+let createdUserId: string | null = null;
+
+// ─── Tiny helpers ────────────────────────────────────────────────────
+
+async function postJson<T = unknown>(path: string, body: unknown, headers?: HeadersInit) {
+	const res = await fetch(`${AUTH_URL}${path}`, {
+		method: 'POST',
+		headers: { 'Content-Type': 'application/json', ...headers },
+		body: JSON.stringify(body),
+	});
+	const json = (await res.json().catch(() => ({}))) as T;
+	return { status: res.status, json };
+}
+
+async function getJson<T = unknown>(url: string, headers?: HeadersInit) {
+	const res = await fetch(url, { headers });
+	const json = (await res.json().catch(() => ({}))) as T;
+	return { status: res.status, json };
+}
+
+async function waitForMail(to: string, timeoutMs = 15000): Promise<{ html: string; text: string }> {
+	const deadline = Date.now() + timeoutMs;
+	while (Date.now() < deadline) {
+		const list = await fetch(
+			`${MAILPIT_URL}/api/v1/search?query=${encodeURIComponent(`to:${to}`)}`
+		);
+		if (list.ok) {
+			const data = (await list.json()) as { messages?: Array<{ ID: string }> };
+			if (data.messages && data.messages.length > 0) {
+				const id = data.messages[0].ID;
+				const full = await fetch(`${MAILPIT_URL}/api/v1/message/${id}`);
+				if (full.ok) {
+					const msg = (await full.json()) as { HTML?: string; Text?: string };
+					return { html: msg.HTML ?? '', text: msg.Text ?? '' };
+				}
+			}
+		}
+		await new Promise((r) => setTimeout(r, 250));
+	}
+	throw new Error(`No email to ${to} arrived within ${timeoutMs}ms`);
+}
+
+function extractVerifyUrl(html: string): string {
+	// Better Auth's verify URL is /api/auth/verify-email?token=...&callbackURL=...
+	// We allow either http://mana-auth:3001 or http://localhost:3091 since the
+	// test runs against the host but mana-auth's BASE_URL might be either.
+	const match = html.match(/https?:\/\/[^\s"'<>]+\/api\/auth\/verify-email\?[^\s"'<>]+/);
+	if (!match) throw new Error(`No verify URL found in email body: ${html.slice(0, 200)}`);
+	return match[0];
+}
+
+async function pgExec(sql: string): Promise<string> {
+	// Shell out to docker exec rather than pulling in a postgres client lib —
+	// the test container is the only place this runs and it has docker.
+	const proc = Bun.spawn(
+		[
+			'docker',
+			'exec',
+			'mana-test-postgres',
+			'psql',
+			'-U',
+			'mana',
+			'-d',
+			'mana_platform',
+			'-t',
+			'-A',
+			'-c',
+			sql,
+		],
+		{ stdout: 'pipe', stderr: 'pipe' }
+	);
+	const out = await new Response(proc.stdout).text();
+	const err = await new Response(proc.stderr).text();
+	const code = await proc.exited;
+	if (code !== 0) throw new Error(`psql failed (${code}): ${err}`);
+	return out.trim();
+}
+
+// ─── Cleanup at the end so failed runs don't leak ────────────────────
+
+afterAll(async () => {
+	if (!createdUserId) return;
+	try {
+		await pgExec(
+			`DELETE FROM auth.encryption_vault_audit WHERE user_id = '${createdUserId}';
+			 DELETE FROM auth.encryption_vaults WHERE user_id = '${createdUserId}';
+			 DELETE FROM auth.users WHERE id = '${createdUserId}';`
+		);
+	} catch (err) {
+		console.warn('cleanup failed:', err);
+	}
+});
+
+// ─── The test ────────────────────────────────────────────────────────
+
+test('full register → verify → login → vault → logout flow', async () => {
+	// 1. Register
+	const reg = await postJson<{ user?: { id: string } }>('/api/v1/auth/register', {
+		email: TEST_EMAIL,
+		password: TEST_PASSWORD,
+		name: TEST_NAME,
+	});
+	expect(reg.status).toBe(200);
+	expect(reg.json.user?.id).toBeTruthy();
+	createdUserId = reg.json.user!.id;
+
+	// 2. Wait for the verification email to land in mailpit
+	const mail = await waitForMail(TEST_EMAIL);
+	expect(mail.html.length).toBeGreaterThan(0);
+
+	// 3. Extract the verify URL
+	const verifyUrl = extractVerifyUrl(mail.html);
+
+	// 4. Hit the verify URL. Better Auth issues a 302 redirect on success.
+	//    Use manual redirect handling so we can assert the redirect itself.
+	//
+	//    Sometimes Better Auth's verify URL points at the internal docker
+	//    hostname `http://mana-auth:3001/...`. Rewrite that to the host-bound
+	//    port so we can actually reach it from outside the docker network.
+	const reachableVerifyUrl = verifyUrl.replace('http://mana-auth:3001', AUTH_URL);
+	const verifyRes = await fetch(reachableVerifyUrl, { redirect: 'manual' });
+	expect([200, 302, 303]).toContain(verifyRes.status);
+
+	// Belt-and-suspenders: confirm the DB row actually flipped.
+	const verified = await pgExec(
+		`SELECT email_verified FROM auth.users WHERE id = '${createdUserId}';`
+	);
+	expect(verified).toBe('t');
+
+	// 5. Login. Expect accessToken (the JWT) and refreshToken (the session token).
+	const login = await postJson<{
+		user?: { id: string };
+		accessToken?: string;
+		refreshToken?: string;
+	}>('/api/v1/auth/login', {
+		email: TEST_EMAIL,
+		password: TEST_PASSWORD,
+	});
+	expect(login.status).toBe(200);
+	expect(login.json.user?.id).toBe(createdUserId);
+	expect(login.json.accessToken).toBeTruthy();
+	expect(login.json.accessToken!.split('.').length).toBe(3); // JWT has 3 segments
+	expect(login.json.refreshToken).toBeTruthy();
+	const jwt = login.json.accessToken!;
+
+	// 6. Validate the JWT against the same service that minted it
+	const validate = await postJson<{ valid: boolean; payload?: { sub: string; email: string } }>(
+		'/api/v1/auth/validate',
+		{ token: jwt }
+	);
+	expect(validate.status).toBe(200);
+	expect(validate.json.valid).toBe(true);
+	expect(validate.json.payload?.sub).toBe(createdUserId);
+	expect(validate.json.payload?.email).toBe(TEST_EMAIL);
+
+	// 7. /me/data round-trip — exercises JWT auth middleware end-to-end
+	const me = await getJson<{ user?: { id: string; email: string } }>(`${AUTH_URL}/api/v1/me/data`, {
+		Authorization: `Bearer ${jwt}`,
+	});
+	expect(me.status).toBe(200);
+	expect(me.json.user?.id).toBe(createdUserId);
+
+	// 8. Encryption vault init — exercises nanoid + MANA_AUTH_KEK + the
+	//    auth.encryption_vaults / auth.encryption_vault_audit tables
+	const vaultInit = await postJson<{ masterKey?: string; kekId?: string; formatVersion?: number }>(
+		'/api/v1/me/encryption-vault/init',
+		{},
+		{ Authorization: `Bearer ${jwt}` }
+	);
+	expect(vaultInit.status).toBe(200);
+	expect(vaultInit.json.masterKey).toBeTruthy();
+	expect(vaultInit.json.formatVersion).toBe(1);
+	expect(vaultInit.json.kekId).toBeTruthy();
+	const mintedKey = vaultInit.json.masterKey!;
+
+	// 9. Vault key retrieval — should return the same master key
+	const vaultKey = await getJson<{ masterKey?: string }>(
+		`${AUTH_URL}/api/v1/me/encryption-vault/key`,
+		{ Authorization: `Bearer ${jwt}` }
+	);
+	expect(vaultKey.status).toBe(200);
+	expect(vaultKey.json.masterKey).toBe(mintedKey);
+
+	// 10. Logout
+	const logout = await postJson<{ success?: boolean }>(
+		'/api/v1/auth/logout',
+		{},
+		{ Authorization: `Bearer ${jwt}` }
+	);
+	expect(logout.status).toBe(200);
+	expect(logout.json.success).toBe(true);
+});
diff --git a/tests/integration/package.json b/tests/integration/package.json
new file mode 100644
index 000000000..7c1b18a10
--- /dev/null
+++ b/tests/integration/package.json
@@ -0,0 +1,9 @@
+{
+	"name": "@mana/integration-tests",
+	"version": "0.0.0",
+	"private": true,
+	"type": "module",
+	"scripts": {
+		"test": "bun test auth-flow.test.ts"
+	}
+}