diff --git a/src/app/api/tags/route.test.ts b/src/app/api/tags/route.test.ts
new file mode 100644
index 0000000..c02f83e
--- /dev/null
+++ b/src/app/api/tags/route.test.ts
@@ -0,0 +1,31 @@
+// @vitest-environment node
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { getCardService } from '@/services/card-service-factory'
+import { GET } from './route'
+
+vi.mock('@/services/card-service-factory', () => ({
+  getCardService: vi.fn(),
+}))
+
+describe('GET /api/tags', () => {
+  const service = vi.mocked(getCardService)
+
+  beforeEach(() => {
+    service.mockReset()
+  })
+
+  it('renvoie la liste des tags', async () => {
+    const serviceMock = { tags: vi.fn().mockResolvedValue(['docker', 'scope']) }
+    service.mockReturnValue(serviceMock as never)
+    const res = await GET()
+    expect(res.status).toBe(200)
+    expect(await res.json()).toEqual(['docker', 'scope'])
+  })
+
+  it('propage les erreurs du service', async () => {
+    const serviceMock = { tags: vi.fn().mockRejectedValue(new Error('boom')) }
+    service.mockReturnValue(serviceMock as never)
+    const res = await GET()
+    expect(res.status).toBe(500)
+  })
+})
diff --git a/src/app/api/tags/route.ts b/src/app/api/tags/route.ts
new file mode 100644
index 0000000..69eef69
--- /dev/null
+++ b/src/app/api/tags/route.ts
@@ -0,0 +1,12 @@
+import { NextResponse } from 'next/server'
+import { handleError } from '@/lib/http'
+import { getCardService } from '@/services/card-service-factory'
+
+export async function GET() {
+  try {
+    const tags = await getCardService().tags()
+    return NextResponse.json(tags)
+  } catch (error) {
+    return handleError(error)
+  }
+}
diff --git a/src/app/cards/[id]/edit/page.test.tsx b/src/app/cards/[id]/edit/page.test.tsx
index 0ccdcac..5401fb4 100644
--- a/src/app/cards/[id]/edit/page.test.tsx
+++ b/src/app/cards/[id]/edit/page.test.tsx
@@ -13,7 +13,7 @@ vi.mock('@/lib/api-client', () => {
   }
   return {
     ApiClientError: ApiClientErrorMock,
-    cardsApi: { get: vi.fn() },
+    cardsApi: { get: vi.fn(), tags: vi.fn().mockResolvedValue([]) },
   }
 })
 
diff --git a/src/app/cards/new/page.test.tsx b/src/app/cards/new/page.test.tsx
index 2aee1d5..719e763 100644
--- a/src/app/cards/new/page.test.tsx
+++ b/src/app/cards/new/page.test.tsx
@@ -6,7 +6,7 @@ vi.mock('@/lib/api-client', () => ({
   ApiClientError: class extends Error {
     status = 0
   },
-  cardsApi: { create: vi.fn() },
+  cardsApi: { create: vi.fn(), tags: vi.fn().mockResolvedValue([]) },
 }))
 
 vi.mock('next/navigation', () => ({
diff --git a/src/app/sw.ts b/src/app/sw.ts
index c0bb34a..62896f2 100644
--- a/src/app/sw.ts
+++ b/src/app/sw.ts
@@ -39,8 +39,7 @@ const runtimeCaching: RuntimeCaching[] = [
   },
   // Payloads RSC des navigations côté client : réseau d'abord
   {
-    matcher: ({ request, sameOrigin }) =>
-      sameOrigin && request.headers.get('rsc') === '1',
+    matcher: ({ request, sameOrigin }) => sameOrigin && request.headers.get('rsc') === '1',
     handler: new NetworkFirst({
       networkTimeoutSeconds: 3,
       cacheName: 'rsc-network-first',
diff --git a/src/components/card-form.test.tsx b/src/components/card-form.test.tsx
index 70ba592..e96132f 100644
--- a/src/components/card-form.test.tsx
+++ b/src/components/card-form.test.tsx
@@ -7,7 +7,7 @@ vi.mock('@/lib/api-client', () => ({
   ApiClientError: class extends Error {
     status = 0
   },
-  cardsApi: { create: vi.fn(), update: vi.fn() },
+  cardsApi: { create: vi.fn(), update: vi.fn(), tags: vi.fn() },
 }))
 
 const routerMock = { push: vi.fn(), refresh: vi.fn() }
@@ -20,6 +20,8 @@ import { cardsApi } from '@/lib/api-client'
 beforeEach(() => {
   vi.mocked(cardsApi.create).mockReset()
   vi.mocked(cardsApi.update).mockReset()
+  vi.mocked(cardsApi.tags).mockReset()
+  vi.mocked(cardsApi.tags).mockResolvedValue([])
   routerMock.push.mockReset()
   routerMock.refresh.mockReset()
 })
@@ -35,6 +37,7 @@ it('crée une carte puis navigue vers son détail (F-05)', async () => {
     question: 'Cest quoi un commit ?',
     response: 'Un snapshot',
     theme: 'git',
+    tags: [],
   })
   await screen.findByText('Enregistrement…')
 })
@@ -57,6 +60,73 @@ it('pré-remplit le formulaire et enregistre une modification (F-06 édition)',
     question: 'Nouvelle question',
     response: 'Ancienne réponse',
     theme: 'git',
+    tags: [],
   })
   expect(routerMock.push).toHaveBeenCalledWith('/cards/c1')
 })
+
+it('ajoute des tags (saisie + suggestion), applique le max de 3 et les envoie', async () => {
+  vi.mocked(cardsApi.tags).mockResolvedValue(['git', 'docker'])
+  vi.mocked(cardsApi.create).mockResolvedValue({ id: 'c1' } as never)
+  render(<CardForm mode="create" />)
+  await userEvent.type(screen.getByLabelText('Question'), 'Q ?')
+  await userEvent.type(screen.getByLabelText('Réponse'), 'R')
+  await userEvent.type(screen.getByLabelText('Thème'), 'git')
+
+  const tagInput = screen.getByLabelText('Ajouter un tag')
+  await userEvent.type(tagInput, 'gi')
+  await userEvent.click(await screen.findByRole('button', { name: '+ git' }))
+
+  await userEvent.type(tagInput, 'DOCKER')
+  await userEvent.keyboard('{Enter}')
+
+  await userEvent.type(tagInput, 'hook')
+  await userEvent.keyboard('{Enter}')
+
+  expect(screen.getByText('Tags (3/3)')).toBeInTheDocument()
+  expect(tagInput).toBeDisabled()
+  await userEvent.type(tagInput, 'extra')
+  await userEvent.keyboard('{Enter}')
+  expect(screen.queryByText('#extra')).not.toBeInTheDocument()
+
+  await userEvent.click(screen.getByRole('button', { name: 'Créer la carte' }))
+  expect(vi.mocked(cardsApi.create)).toHaveBeenCalledWith({
+    question: 'Q ?',
+    response: 'R',
+    theme: 'git',
+    tags: ['git', 'docker', 'hook'],
+  })
+})
+
+it('refuse un tag en doublon et signale une erreur', async () => {
+  vi.mocked(cardsApi.tags).mockResolvedValue(['git'])
+  render(<CardForm mode="create" />)
+  const tagInput = screen.getByLabelText('Ajouter un tag')
+  await userEvent.type(tagInput, 'git')
+  await userEvent.keyboard('{Enter}')
+  await userEvent.type(tagInput, 'GIT')
+  await userEvent.keyboard('{Enter}')
+  expect(screen.getByRole('alert')).toHaveTextContent('déjà présent')
+  expect(screen.getAllByText('#git')).toHaveLength(1)
+})
+
+it('pré-remplit les tags en édition et permet d en retirer', async () => {
+  vi.mocked(cardsApi.update).mockResolvedValue({ id: 'c1' } as never)
+  render(
+    <CardForm
+      mode="edit"
+      cardId="c1"
+      initial={{ question: 'A', response: 'R', theme: 'git', tags: ['git', 'scope'] }}
+    />,
+  )
+  expect(screen.getByText('Tags (2/3)')).toBeInTheDocument()
+  await userEvent.click(screen.getByRole('button', { name: 'Retirer le tag git' }))
+  expect(screen.getByText('Tags (1/3)')).toBeInTheDocument()
+  await userEvent.click(screen.getByRole('button', { name: 'Enregistrer' }))
+  expect(vi.mocked(cardsApi.update)).toHaveBeenCalledWith('c1', {
+    question: 'A',
+    response: 'R',
+    theme: 'git',
+    tags: ['scope'],
+  })
+})
diff --git a/src/components/card-form.tsx b/src/components/card-form.tsx
index ddae030..a207228 100644
--- a/src/components/card-form.tsx
+++ b/src/components/card-form.tsx
@@ -1,29 +1,89 @@
 'use client'
 
 import { useRouter } from 'next/navigation'
-import { useState } from 'react'
+import { useEffect, useState } from 'react'
 import type { CardInput } from '@/domain/card'
 import { ApiClientError, cardsApi } from '@/lib/api-client'
 
+const MAX_TAGS = 3
+
 interface CardFormProps {
   mode: 'create' | 'edit'
   cardId?: string
   initial?: CardInput
 }
 
+function normalizeTag(value: string): string {
+  return value.trim().toLowerCase()
+}
+
 export function CardForm({ mode, cardId, initial }: CardFormProps) {
   const router = useRouter()
   const [question, setQuestion] = useState(initial?.question ?? '')
   const [response, setResponse] = useState(initial?.response ?? '')
   const [theme, setTheme] = useState(initial?.theme ?? '')
+  const [tags, setTags] = useState<string[]>(initial?.tags ?? [])
+  const [tagInput, setTagInput] = useState('')
+  const [availableTags, setAvailableTags] = useState<string[]>([])
+  const [tagError, setTagError] = useState<string | null>(null)
   const [error, setError] = useState<string | null>(null)
   const [saving, setSaving] = useState(false)
 
+  useEffect(() => {
+    let cancelled = false
+    cardsApi
+      .tags()
+      .then((data) => {
+        if (!cancelled) setAvailableTags(data)
+      })
+      .catch(() => {
+        if (!cancelled) setAvailableTags([])
+      })
+    return () => {
+      cancelled = true
+    }
+  }, [])
+
+  const suggestions = availableTags.filter(
+    (tag) => tag.includes(normalizeTag(tagInput)) && !tags.includes(tag),
+  )
+
+  function addTag(raw: string) {
+    const tag = normalizeTag(raw)
+    if (!tag) return
+    if (tags.includes(tag)) {
+      setTagError(`Le tag « ${tag} » est déjà présent`)
+      return
+    }
+    if (tags.length >= MAX_TAGS) {
+      setTagError(`Maximum ${MAX_TAGS} tags par carte`)
+      return
+    }
+    setTags((current) => [...current, tag])
+    setTagInput('')
+    setTagError(null)
+  }
+
+  function removeTag(tag: string) {
+    setTags((current) => current.filter((t) => t !== tag))
+    setTagError(null)
+  }
+
+  function handleTagKeyDown(e: React.KeyboardEvent<HTMLInputElement>) {
+    if (e.key === 'Enter') {
+      e.preventDefault()
+      addTag(tagInput)
+    } else if (e.key === 'Escape') {
+      setTagInput('')
+      setTagError(null)
+    }
+  }
+
   async function handleSubmit(e: React.FormEvent) {
     e.preventDefault()
     setSaving(true)
     setError(null)
-    const input: CardInput = { question, response, theme }
+    const input: CardInput = { question, response, theme, tags }
     try {
       if (mode === 'create') {
         const card = await cardsApi.create(input)
@@ -83,6 +143,64 @@ export function CardForm({ mode, cardId, initial }: CardFormProps) {
           className="mt-1 w-full rounded-lg border border-slate-300 px-3 py-2"
         />
       </div>
+      <div>
+        <span className="block text-sm font-medium text-slate-700">
+          Tags ({tags.length}/{MAX_TAGS})
+        </span>
+        {tags.length > 0 && (
+          <ul className="mt-1 flex flex-wrap gap-1.5">
+            {tags.map((tag) => (
+              <li
+                key={tag}
+                className="flex items-center gap-1 rounded-full bg-slate-100 px-2 py-0.5 text-xs text-slate-600"
+              >
+                #{tag}
+                <button
+                  type="button"
+                  aria-label={`Retirer le tag ${tag}`}
+                  onClick={() => removeTag(tag)}
+                  className="text-slate-400 hover:text-slate-700"
+                >
+                  ×
+                </button>
+              </li>
+            ))}
+          </ul>
+        )}
+        <input
+          id="tags"
+          value={tagInput}
+          onChange={(e) => {
+            setTagInput(e.target.value)
+            setTagError(null)
+          }}
+          onKeyDown={handleTagKeyDown}
+          placeholder="Saisis un tag puis Entrée (ex. git)"
+          aria-label="Ajouter un tag"
+          disabled={tags.length >= MAX_TAGS}
+          className="mt-1 w-full rounded-lg border border-slate-300 px-3 py-2 disabled:opacity-50"
+        />
+        {tagError && (
+          <p role="alert" className="mt-1 text-sm text-red-600">
+            {tagError}
+          </p>
+        )}
+        {suggestions.length > 0 && (
+          <ul className="mt-2 flex flex-wrap gap-1.5">
+            {suggestions.slice(0, 6).map((tag) => (
+              <li key={tag}>
+                <button
+                  type="button"
+                  onClick={() => addTag(tag)}
+                  className="rounded-full border border-slate-200 px-2 py-0.5 text-xs text-slate-600 hover:bg-slate-50"
+                >
+                  + {tag}
+                </button>
+              </li>
+            ))}
+          </ul>
+        )}
+      </div>
       <div className="flex items-center gap-3">
         <button
           type="submit"
diff --git a/src/domain/card-repository.ts b/src/domain/card-repository.ts
index bf9bb32..e586988 100644
--- a/src/domain/card-repository.ts
+++ b/src/domain/card-repository.ts
@@ -9,4 +9,5 @@ export interface CardRepository {
   findRandom(): Promise<Card | null>
   findRandomByTheme(theme: string): Promise<Card | null>
   findThemes(): Promise<string[]>
+  findTags(): Promise<string[]>
 }
diff --git a/src/domain/card-schemas.test.ts b/src/domain/card-schemas.test.ts
index bb42b0d..30e3323 100644
--- a/src/domain/card-schemas.test.ts
+++ b/src/domain/card-schemas.test.ts
@@ -27,6 +27,41 @@ describe('createCardSchema', () => {
   it('rejette un thème manquant', () => {
     expect(() => createCardSchema.parse({ question: 'Q', response: 'R' })).toThrow()
   })
+
+  it('normalise les tags (trim + minuscules) et supprime les doublons', () => {
+    const result = createCardSchema.parse({
+      question: 'Q',
+      response: 'R',
+      theme: 'git',
+      tags: [' Git ', 'git', 'HOOK', 'hook'],
+    })
+    expect(result.tags).toEqual(['git', 'hook'])
+  })
+
+  it('rejette plus de 3 tags', () => {
+    expect(() =>
+      createCardSchema.parse({
+        question: 'Q',
+        response: 'R',
+        theme: 'git',
+        tags: ['a', 'b', 'c', 'd'],
+      }),
+    ).toThrow()
+  })
+
+  it('rejette un tag vide ou trop long', () => {
+    expect(() =>
+      createCardSchema.parse({ question: 'Q', response: 'R', theme: 'git', tags: ['  '] }),
+    ).toThrow()
+    expect(() =>
+      createCardSchema.parse({
+        question: 'Q',
+        response: 'R',
+        theme: 'git',
+        tags: ['x'.repeat(31)],
+      }),
+    ).toThrow()
+  })
 })
 
 describe('updateCardSchema', () => {
diff --git a/src/domain/card-schemas.ts b/src/domain/card-schemas.ts
index 477a520..b151b07 100644
--- a/src/domain/card-schemas.ts
+++ b/src/domain/card-schemas.ts
@@ -1,10 +1,21 @@
 import { z } from 'zod'
 
+const tagSchema = z
+  .string()
+  .trim()
+  .toLowerCase()
+  .min(1, 'Tag vide')
+  .max(30, 'Tag trop long (30 caractères max)')
+
 export const createCardSchema = z.object({
   question: z.string().trim().min(1, 'La question est requise').max(1000, 'Question trop longue'),
   response: z.string().trim().min(1, 'La réponse est requise').max(2000, 'Réponse trop longue'),
   theme: z.string().trim().min(1, 'Le thème est requis').max(50, 'Thème trop long'),
-  tags: z.array(z.string().trim().min(1, 'Tag vide')).max(50, 'Trop de tags').optional(),
+  tags: z
+    .array(tagSchema)
+    .refine((tags) => new Set(tags).size <= 3, 'Maximum 3 tags par carte')
+    .transform((tags) => [...new Set(tags)])
+    .optional(),
 })
 
 export const updateCardSchema = createCardSchema.partial()
diff --git a/src/lib/api-client.test.ts b/src/lib/api-client.test.ts
index 63ab202..a5c01ba 100644
--- a/src/lib/api-client.test.ts
+++ b/src/lib/api-client.test.ts
@@ -74,6 +74,12 @@ describe('cardsApi', () => {
     expectRequest('GET', '/api/themes')
   })
 
+  it('tags() appelle GET /api/tags', async () => {
+    fetchMock.mockResolvedValue(jsonResponse(['scope', 'fonction']))
+    await expect(cardsApi.tags()).resolves.toEqual(['scope', 'fonction'])
+    expectRequest('GET', '/api/tags')
+  })
+
   it('lève ApiClientError avec le message de l API sur une erreur 404', async () => {
     fetchMock.mockResolvedValue(
       jsonResponse({ error: 'NotFoundError', message: 'Carte inconnue' }, 404),
diff --git a/src/lib/api-client.ts b/src/lib/api-client.ts
index 3b65199..e40b0d5 100644
--- a/src/lib/api-client.ts
+++ b/src/lib/api-client.ts
@@ -55,4 +55,5 @@ export const cardsApi = {
   random: (theme?: string) =>
     request<Card>(`/api/cards/random${theme ? `?theme=${encodeURIComponent(theme)}` : ''}`),
   themes: () => request<string[]>('/api/themes'),
+  tags: () => request<string[]>('/api/tags'),
 }
diff --git a/src/repositories/mongo-card-repository.test.ts b/src/repositories/mongo-card-repository.test.ts
index 4f709f1..1d84260 100644
--- a/src/repositories/mongo-card-repository.test.ts
+++ b/src/repositories/mongo-card-repository.test.ts
@@ -141,4 +141,11 @@ describe('MongoCardRepository', () => {
     collection.distinct.mockResolvedValueOnce(['react', 'docker'])
     await expect(repo.findThemes()).resolves.toEqual(['docker', 'react'])
   })
+
+  it('findTags renvoie les tags distincts triés', async () => {
+    const { repo, collection } = setup()
+    collection.distinct.mockResolvedValueOnce(['scope', 'docker'])
+    await expect(repo.findTags()).resolves.toEqual(['docker', 'scope'])
+    expect(collection.distinct).toHaveBeenCalledWith('tags')
+  })
 })
diff --git a/src/repositories/mongo-card-repository.ts b/src/repositories/mongo-card-repository.ts
index 07110f8..2cfc8af 100644
--- a/src/repositories/mongo-card-repository.ts
+++ b/src/repositories/mongo-card-repository.ts
@@ -124,4 +124,9 @@ export class MongoCardRepository implements CardRepository {
     const themes: string[] = await this.collection.distinct('theme')
     return themes.sort()
   }
+
+  async findTags(): Promise<string[]> {
+    const tags = await this.collection.distinct('tags')
+    return tags.map((tag) => String(tag)).sort()
+  }
 }
diff --git a/src/repositories/mysql-card-repository.test.ts b/src/repositories/mysql-card-repository.test.ts
index 9b9b216..2f497b3 100644
--- a/src/repositories/mysql-card-repository.test.ts
+++ b/src/repositories/mysql-card-repository.test.ts
@@ -154,4 +154,12 @@ describe('MysqlCardRepository', () => {
     query.mockResolvedValueOnce([[{ theme: 'docker' }, { theme: 'javascript' }]])
     await expect(repo.findThemes()).resolves.toEqual(['docker', 'javascript'])
   })
+
+  it('findTags agrège les tags distincts et les trie', async () => {
+    const { repo, query } = setup()
+    query.mockResolvedValueOnce([
+      [{ tags: '["scope","git"]' }, { tags: null }, { tags: ['docker', 'git'] }],
+    ])
+    await expect(repo.findTags()).resolves.toEqual(['docker', 'git', 'scope'])
+  })
 })
diff --git a/src/repositories/mysql-card-repository.ts b/src/repositories/mysql-card-repository.ts
index 0bd034e..a76e9fa 100644
--- a/src/repositories/mysql-card-repository.ts
+++ b/src/repositories/mysql-card-repository.ts
@@ -147,4 +147,15 @@ export class MysqlCardRepository implements CardRepository {
     )
     return rows.map((row) => row.theme as string)
   }
+
+  async findTags(): Promise<string[]> {
+    const [rows] = await this.pool.query<RowDataPacket[]>('SELECT tags FROM cards')
+    const tags = new Set<string>()
+    for (const row of rows) {
+      for (const tag of this.parseTags(row.tags)) {
+        tags.add(tag)
+      }
+    }
+    return [...tags].sort()
+  }
 }
diff --git a/src/services/card-service.test.ts b/src/services/card-service.test.ts
index 1cd14ab..480e2fa 100644
--- a/src/services/card-service.test.ts
+++ b/src/services/card-service.test.ts
@@ -27,6 +27,7 @@ function setup() {
     findRandom: vi.fn(),
     findRandomByTheme: vi.fn(),
     findThemes: vi.fn(),
+    findTags: vi.fn(),
   }
   const service = new CardService(repository as unknown as CardRepository)
   return { service, repository }
@@ -112,4 +113,10 @@ describe('CardService', () => {
     repository.findThemes.mockResolvedValueOnce(['docker', 'git'])
     await expect(service.themes()).resolves.toEqual(['docker', 'git'])
   })
+
+  it('tags renvoie la liste des tags', async () => {
+    const { service, repository } = setup()
+    repository.findTags.mockResolvedValueOnce(['fonction', 'scope'])
+    await expect(service.tags()).resolves.toEqual(['fonction', 'scope'])
+  })
 })
diff --git a/src/services/card-service.ts b/src/services/card-service.ts
index b3fedeb..b2cd164 100644
--- a/src/services/card-service.ts
+++ b/src/services/card-service.ts
@@ -51,4 +51,8 @@ export class CardService {
   async themes(): Promise<string[]> {
     return this.repository.findThemes()
   }
+
+  async tags(): Promise<string[]> {
+    return this.repository.findTags()
+  }
 }