diff --git a/backend/src/database/SqliteAdapter.ts b/backend/src/database/SqliteAdapter.ts
index 042efec..e85efb8 100644
--- a/backend/src/database/SqliteAdapter.ts
+++ b/backend/src/database/SqliteAdapter.ts
@@ -400,7 +400,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createGlobalFolder(data: Partial<DBGlobalBlockFolder>): DBGlobalBlockFolder {
-    const id = data.id ?? `gfolder-${Date.now()}`;
+    const id = data.id ?? `gfolder-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO global_block_folders (id, name, parent_id) VALUES (?, ?, ?)',
     ).run(id, data.name ?? 'Neuer Ordner', data.parent_id ?? null);
@@ -438,7 +438,7 @@ export class SqliteAdapter implements DatabaseInterface {
   }
 
   createGlobalBlock(data: Partial<DBGlobalBlock>): DBGlobalBlock {
-    const id = data.id ?? `gblock-${Date.now()}`;
+    const id = data.id ?? `gblock-${randomUUID().slice(0, 8)}`;
     this.db.prepare(
       'INSERT INTO global_blocks (id, folder_id, name, block_data, svg_data) VALUES (?, ?, ?, ?, ?)',
     ).run(id, data.folder_id ?? null, data.name ?? 'Global Block', data.block_data ?? '{}', data.svg_data ?? null);
diff --git a/backend/src/routes/globalBlocks.ts b/backend/src/routes/globalBlocks.ts
index 31ebbba..0cebe5c 100644
--- a/backend/src/routes/globalBlocks.ts
+++ b/backend/src/routes/globalBlocks.ts
@@ -164,4 +164,66 @@ export function registerGlobalBlockRoutes(fastify: FastifyInstance, db: Database
     if (!ok) return reply.code(404).send({ error: 'Global block not found' });
     return reply.code(204).send();
   });
+
+  // ─── Task F1: Library-Paket Export/Import (.wcadlib) ──────
+
+  // Export: komplette Library als JSON-Paket (Ordner + Blöcke)
+  fastify.get('/api/global-blocks/export', async (request, reply) => {
+    if (!requireAuth(request, reply, authService)) return;
+    const folders = db.listGlobalFolders();
+    const blocks = db.listGlobalBlocks();
+    return {
+      format: 'wcadlib',
+      version: 1,
+      exported_at: new Date().toISOString(),
+      folders: folders.map((f) => ({ id: f.id, name: f.name, parent_id: f.parent_id })),
+      blocks: blocks.map((b) => ({
+        name: b.name,
+        folder_id: b.folder_id,
+        block_data: b.block_data,
+        svg_data: b.svg_data,
+      })),
+    };
+  });
+
+  // Import: .wcadlib-Paket einspielen (IDs neu, Ordner-Hierarchie über Mapping erhalten)
+  fastify.post('/api/global-blocks/import', async (request, reply) => {
+    if (!requireAuth(request, reply, authService)) return;
+    const pkg = request.body as {
+      format?: string;
+      folders?: Array<{ id: string; name: string; parent_id: string | null }>;
+      blocks?: Array<{ name: string; folder_id: string | null; block_data: string; svg_data: string | null }>;
+    };
+    if (!pkg || pkg.format !== 'wcadlib' || !Array.isArray(pkg.blocks)) {
+      return reply.code(400).send({ error: 'Invalid wcadlib package (format != wcadlib or blocks missing)' });
+    }
+
+    // Ordner mit ID-Mapping importieren:
+    const folderIdMap = new Map<string, string>();
+    const sortedFolders = [...(pkg.folders ?? [])].sort((a, b) => {
+      if (a.parent_id === b.parent_id) return 0;
+      if (a.parent_id === null) return -1;
+      if (b.parent_id === null) return 1;
+      return 0;
+    });
+    for (const f of sortedFolders) {
+      const newParent = f.parent_id ? folderIdMap.get(f.parent_id) ?? null : null;
+      const created = db.createGlobalFolder({ name: f.name, parent_id: newParent });
+      folderIdMap.set(f.id, created.id);
+    }
+
+    // Blöcke importieren:
+    let imported = 0;
+    for (const b of pkg.blocks) {
+      const newFolderId = b.folder_id ? folderIdMap.get(b.folder_id) ?? null : null;
+      db.createGlobalBlock({
+        name: b.name,
+        folder_id: newFolderId,
+        block_data: b.block_data,
+        svg_data: b.svg_data,
+      });
+      imported++;
+    }
+    return reply.code(201).send({ imported_blocks: imported, imported_folders: folderIdMap.size });
+  });
 }
diff --git a/backend/tests/globalBlocks.test.ts b/backend/tests/globalBlocks.test.ts
index c0c719e..cafad0b 100644
--- a/backend/tests/globalBlocks.test.ts
+++ b/backend/tests/globalBlocks.test.ts
@@ -424,3 +424,104 @@ describe('Global Blocks API', () => {
     });
   });
 });
+
+// ─── Task F1: Library-Paket Export/Import (.wcadlib) ──────
+
+describe('Global Blocks API – F1 export/import', () => {
+  let app: FastifyInstance;
+  let db: SqliteAdapter;
+  let authToken: string;
+
+  beforeAll(async () => {
+    db = new SqliteAdapter(':memory:');
+    await db.init();
+    app = await createServer({ db, port: 0 });
+    await app.ready();
+    const regRes = await app.inject({
+      method: 'POST',
+      url: '/api/auth/register',
+      payload: { email: 'f1-export@example.com', password: 'Password123!', name: 'F1 Test', role: 'admin' },
+    });
+    authToken = JSON.parse(regRes.body).session.token;
+  });
+
+  afterAll(async () => {
+    await app.close();
+    db.close();
+  });
+
+  it('GET /api/global-blocks/export liefert wcadlib-Paket mit folders+blocks', async () => {
+    // Setup: 1 Ordner + 1 Block
+    const folder = await app.inject({
+      method: 'POST',
+      url: '/api/global-folders',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { name: 'F1-Ordner' },
+    });
+    const folderId = JSON.parse(folder.body).id;
+    await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { name: 'F1-Block', folder_id: folderId, block_data: '{"type":"rect"}' },
+    });
+
+    const res = await app.inject({
+      method: 'GET',
+      url: '/api/global-blocks/export',
+      headers: { authorization: `Bearer ${authToken}` },
+    });
+    expect(res.statusCode).toBe(200);
+    const pkg = JSON.parse(res.body);
+    expect(pkg.format).toBe('wcadlib');
+    expect(Array.isArray(pkg.folders)).toBe(true);
+    expect(Array.isArray(pkg.blocks)).toBe(true);
+    expect(pkg.folders.length).toBeGreaterThanOrEqual(1);
+    expect(pkg.blocks.length).toBeGreaterThanOrEqual(1);
+  });
+
+  it('POST /api/global-blocks/import spielt Paket mit Ordner-Mapping ein', async () => {
+    const pkg = {
+      format: 'wcadlib',
+      version: 1,
+      folders: [
+        { id: 'src-folder-1', name: 'Import-Ordner', parent_id: null },
+      ],
+      blocks: [
+        { name: 'Import-Block', folder_id: 'src-folder-1', block_data: '{"type":"circle"}', svg_data: null },
+        { name: 'Import-Block-Root', folder_id: null, block_data: '{}', svg_data: null },
+      ],
+    };
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks/import',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: pkg,
+    });
+    expect(res.statusCode, res.body).toBe(201);
+    const body = JSON.parse(res.body);
+    expect(body.imported_blocks).toBe(2);
+    expect(body.imported_folders).toBe(1);
+
+    // Block im importierten Ordner auffindbar:
+    const blocks = await app.inject({
+      method: 'GET',
+      url: '/api/global-blocks',
+      headers: { authorization: `Bearer ${authToken}` },
+    });
+    const list = JSON.parse(blocks.body) as Array<{ name: string; folder_id: string | null }>;
+    const importedBlock = list.find((b) => b.name === 'Import-Block');
+    expect(importedBlock).toBeDefined();
+    expect(importedBlock!.folder_id).not.toBeNull(); // Mapping erhalten
+  });
+
+  it('Import mit falschem format liefert 400', async () => {
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/global-blocks/import',
+      headers: { authorization: `Bearer ${authToken}` },
+      payload: { format: 'wrong', blocks: [] },
+    });
+    expect(res.statusCode).toBe(400);
+  });
+});