diff --git a/src/server/db/campaigns.test.ts b/src/server/db/campaigns.test.ts
new file mode 100644
index 0000000..74c475e
--- /dev/null
+++ b/src/server/db/campaigns.test.ts
@@ -0,0 +1,122 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+const mockClient = vi.hoisted(() => ({
+  execute: vi.fn(),
+  query: vi.fn(),
+}))
+
+vi.mock('./tenant', () => ({
+  withTenant: vi.fn((_, fn) => fn(mockClient)),
+}))
+
+import {
+  createCampaign,
+  getCampaign,
+  updateCampaign,
+  listCampaigns,
+  updateCampaignStatus,
+} from './campaigns'
+
+const mockRow = {
+  id: 'uuid-1',
+  name: 'Test',
+  subject: 'Betreff',
+  html_body: '<p>Hi</p>',
+  plain_body: 'Hi',
+  status: 'draft',
+  scheduled_at: null,
+  cron_expression: null,
+  created_at: new Date('2026-01-01'),
+  updated_at: new Date('2026-01-01'),
+}
+
+describe('createCampaign', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('gibt erstellte Kampagne zurück', async () => {
+    mockClient.query.mockResolvedValueOnce([mockRow])
+    const result = await createCampaign('tenant1', {
+      name: 'Test',
+      subject: 'Betreff',
+      htmlBody: '<p>Hi</p>',
+      plainBody: 'Hi',
+    })
+    expect(result.ok).toBe(true)
+    if (result.ok) expect(result.data.name).toBe('Test')
+  })
+
+  it('mapped html_body → htmlBody korrekt', async () => {
+    mockClient.query.mockResolvedValueOnce([mockRow])
+    const result = await createCampaign('tenant1', {
+      name: 'Test', subject: 'Betreff', htmlBody: '<p>Hi</p>', plainBody: 'Hi',
+    })
+    if (result.ok) expect(result.data.htmlBody).toBe('<p>Hi</p>')
+  })
+})
+
+describe('getCampaign', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('gibt Kampagne zurück wenn gefunden', async () => {
+    mockClient.query.mockResolvedValueOnce([mockRow])
+    const result = await getCampaign('tenant1', 'uuid-1')
+    expect(result.ok).toBe(true)
+  })
+
+  it('gibt err zurück wenn nicht gefunden', async () => {
+    mockClient.query.mockResolvedValueOnce([])
+    const result = await getCampaign('tenant1', 'uuid-1')
+    expect(result.ok).toBe(false)
+    if (!result.ok) expect(result.error.message).toContain('nicht gefunden')
+  })
+})
+
+describe('listCampaigns', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('gibt leeres Array zurück wenn keine Kampagnen', async () => {
+    mockClient.query.mockResolvedValueOnce([])
+    const result = await listCampaigns('tenant1')
+    expect(result.ok).toBe(true)
+    if (result.ok) expect(result.data).toEqual([])
+  })
+
+  it('gibt mehrere Kampagnen zurück', async () => {
+    mockClient.query.mockResolvedValueOnce([mockRow, { ...mockRow, id: 'uuid-2' }])
+    const result = await listCampaigns('tenant1')
+    if (result.ok) expect(result.data).toHaveLength(2)
+  })
+})
+
+describe('updateCampaign', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('aktualisiert nur übergebene Felder', async () => {
+    mockClient.query.mockResolvedValueOnce([{ ...mockRow, name: 'Neu' }])
+    const result = await updateCampaign('tenant1', 'uuid-1', { name: 'Neu' })
+    expect(result.ok).toBe(true)
+    if (result.ok) expect(result.data.name).toBe('Neu')
+  })
+
+  it('gibt err zurück wenn keine Felder übergeben', async () => {
+    const result = await updateCampaign('tenant1', 'uuid-1', {})
+    expect(result.ok).toBe(false)
+  })
+})
+
+describe('updateCampaignStatus', () => {
+  beforeEach(() => vi.clearAllMocks())
+
+  it('setzt Status auf scheduled', async () => {
+    mockClient.query.mockResolvedValueOnce([{ ...mockRow, status: 'scheduled' }])
+    const result = await updateCampaignStatus('tenant1', 'uuid-1', 'scheduled')
+    expect(result.ok).toBe(true)
+    if (result.ok) expect(result.data.status).toBe('scheduled')
+  })
+
+  it('gibt err zurück wenn Kampagne nicht gefunden', async () => {
+    mockClient.query.mockResolvedValueOnce([])
+    const result = await updateCampaignStatus('tenant1', 'uuid-1', 'sent')
+    expect(result.ok).toBe(false)
+  })
+})
diff --git a/src/server/db/campaigns.ts b/src/server/db/campaigns.ts
new file mode 100644
index 0000000..67bdfac
--- /dev/null
+++ b/src/server/db/campaigns.ts
@@ -0,0 +1,115 @@
+import { withTenant } from './tenant'
+import { ok, err, type Result } from '../../lib/result'
+import type { Campaign, CampaignStatus } from '../../types'
+import type { CreateCampaignInput, UpdateCampaignInput } from '../../lib/validation'
+
+function rowToCampaign(row: Record<string, unknown>): Campaign {
+  return {
+    id: row.id as string,
+    name: row.name as string,
+    subject: row.subject as string,
+    htmlBody: row.html_body as string,
+    plainBody: row.plain_body as string,
+    status: row.status as CampaignStatus,
+    scheduledAt: row.scheduled_at ? new Date(row.scheduled_at as string) : null,
+    cronExpression: row.cron_expression as string | null,
+    createdAt: new Date(row.created_at as string),
+    updatedAt: new Date(row.updated_at as string),
+  }
+}
+
+export async function createCampaign(
+  tenantId: string,
+  input: CreateCampaignInput
+): Promise<Result<Campaign>> {
+  try {
+    const rows = await withTenant(tenantId, (client) =>
+      client.query(
+        `INSERT INTO campaigns (name, subject, html_body, plain_body)
+         VALUES ($1, $2, $3, $4) RETURNING *`,
+        [input.name, input.subject, input.htmlBody, input.plainBody]
+      )
+    )
+    return ok(rowToCampaign(rows[0]))
+  } catch (e) {
+    return err(e instanceof Error ? e : new Error(String(e)))
+  }
+}
+
+export async function getCampaign(
+  tenantId: string,
+  id: string
+): Promise<Result<Campaign>> {
+  try {
+    const rows = await withTenant(tenantId, (client) =>
+      client.query('SELECT * FROM campaigns WHERE id = $1', [id])
+    )
+    if (rows.length === 0) return err(new Error('Kampagne nicht gefunden'))
+    return ok(rowToCampaign(rows[0]))
+  } catch (e) {
+    return err(e instanceof Error ? e : new Error(String(e)))
+  }
+}
+
+export async function listCampaigns(tenantId: string): Promise<Result<Campaign[]>> {
+  try {
+    const rows = await withTenant(tenantId, (client) =>
+      client.query('SELECT * FROM campaigns ORDER BY created_at DESC', [])
+    )
+    return ok(rows.map(rowToCampaign))
+  } catch (e) {
+    return err(e instanceof Error ? e : new Error(String(e)))
+  }
+}
+
+export async function updateCampaign(
+  tenantId: string,
+  id: string,
+  input: UpdateCampaignInput
+): Promise<Result<Campaign>> {
+  const fields: string[] = []
+  const values: unknown[] = []
+  let idx = 1
+
+  if (input.name !== undefined) { fields.push(`name = $${idx++}`); values.push(input.name) }
+  if (input.subject !== undefined) { fields.push(`subject = $${idx++}`); values.push(input.subject) }
+  if (input.htmlBody !== undefined) { fields.push(`html_body = $${idx++}`); values.push(input.htmlBody) }
+  if (input.plainBody !== undefined) { fields.push(`plain_body = $${idx++}`); values.push(input.plainBody) }
+
+  if (fields.length === 0) return err(new Error('Keine Felder zum Aktualisieren'))
+
+  try {
+    values.push(id)
+    const rows = await withTenant(tenantId, (client) =>
+      client.query(
+        `UPDATE campaigns SET ${fields.join(', ')} WHERE id = $${idx} AND status = 'draft' RETURNING *`,
+        values
+      )
+    )
+    if (rows.length === 0) return err(new Error('Kampagne nicht gefunden oder nicht im Draft-Status'))
+    return ok(rowToCampaign(rows[0]))
+  } catch (e) {
+    return err(e instanceof Error ? e : new Error(String(e)))
+  }
+}
+
+export async function updateCampaignStatus(
+  tenantId: string,
+  id: string,
+  status: CampaignStatus,
+  extra?: { scheduledAt?: Date; cronExpression?: string }
+): Promise<Result<Campaign>> {
+  try {
+    const rows = await withTenant(tenantId, (client) =>
+      client.query(
+        `UPDATE campaigns SET status = $1, scheduled_at = $2, cron_expression = $3
+         WHERE id = $4 RETURNING *`,
+        [status, extra?.scheduledAt ?? null, extra?.cronExpression ?? null, id]
+      )
+    )
+    if (rows.length === 0) return err(new Error('Kampagne nicht gefunden'))
+    return ok(rowToCampaign(rows[0]))
+  } catch (e) {
+    return err(e instanceof Error ? e : new Error(String(e)))
+  }
+}