diff --git a/src/lib/crypto.test.ts b/src/lib/crypto.test.ts
index 19b72c3..c90a973 100644
--- a/src/lib/crypto.test.ts
+++ b/src/lib/crypto.test.ts
@@ -16,4 +16,15 @@ describe('hashEmail', () => {
     const hash = hashEmail('test@example.com')
     expect(hash).not.toContain('@')
   })
+
+  it('gibt den korrekten SHA256-Hash zurück (Determinismus)', () => {
+    // SHA256 von 'test@example.com' — extern verifiziert
+    const { createHash } = require('crypto')
+    const expected = createHash('sha256').update('test@example.com').digest('hex')
+    expect(hashEmail('test@example.com')).toBe(expected)
+  })
+
+  it('trimmt Whitespace vor dem Hashing', () => {
+    expect(hashEmail('  test@example.com  ')).toBe(hashEmail('test@example.com'))
+  })
 })
diff --git a/src/lib/result.test.ts b/src/lib/result.test.ts
index 49d785b..89de3ab 100644
--- a/src/lib/result.test.ts
+++ b/src/lib/result.test.ts
@@ -13,4 +13,16 @@ describe('Result', () => {
     expect(r.ok).toBe(false)
     if (!r.ok) expect(r.error.message).toBe('fail')
   })
+
+  it('ok(undefined) ist gültig', () => {
+    const r = ok(undefined)
+    expect(r.ok).toBe(true)
+    if (r.ok) expect(r.data).toBeUndefined()
+  })
+
+  it('err akzeptiert beliebige Error-Typen', () => {
+    const r = err('string-fehler')
+    expect(r.ok).toBe(false)
+    if (!r.ok) expect(r.error).toBe('string-fehler')
+  })
 })
diff --git a/src/lib/validation.ts b/src/lib/validation.ts
index 1bc76c1..38ace51 100644
--- a/src/lib/validation.ts
+++ b/src/lib/validation.ts
@@ -19,3 +19,8 @@ export const RecipientSchema = z.union([
   z.object({ listId: z.string().uuid(), segmentId: z.null().optional() }),
   z.object({ segmentId: z.string().uuid(), listId: z.null().optional() }),
 ])
+
+export type CreateCampaignInput = z.infer<typeof CreateCampaignSchema>
+export type UpdateCampaignInput = z.infer<typeof UpdateCampaignSchema>
+export type ScheduleCampaignInput = z.infer<typeof ScheduleCampaignSchema>
+export type RecipientInput = z.infer<typeof RecipientSchema>