diff --git a/src/lib/transfer.ts b/src/lib/transfer.ts
new file mode 100644
index 0000000..0cb5091
--- /dev/null
+++ b/src/lib/transfer.ts
@@ -0,0 +1,516 @@
+import "server-only";
+import { prisma } from "./db";
+import { env } from "./env";
+import { ensureTitle } from "./catalog";
+import { addToLibrary } from "./library";
+import { episodeCode } from "./labels";
+import type { EntryStatus, TitleType } from "@/generated/prisma/client";
+
+/**
+ * Daten hinein und hinaus.
+ *
+ * Hinein: Trakt.tv-Export (JSON) und CSV, wie es Serienjunkies, TV Time und
+ * Tabellenkalkulationen ausspucken. Hinaus: dieselben Daten als CSV oder JSON.
+ *
+ * Grundhaltung beim Import: **nichts überschreiben**. Was schon in der
+ * Bibliothek liegt, bleibt wie es ist; es kommt nur dazu, was fehlt. Ein
+ * Import soll niemand versehentlich seinen Fortschritt kosten.
+ */
+
+export type ImportSummary = {
+  processed: number;
+  added: number;
+  skipped: number;
+  watchesAdded: number;
+  errors: string[];
+};
+
+const STATUS_ALIASES: Record<string, EntryStatus> = {
+  watching: "WATCHING",
+  "schaue gerade": "WATCHING",
+  laufend: "WATCHING",
+  paused: "PAUSED",
+  pausiert: "PAUSED",
+  hold: "PAUSED",
+  completed: "COMPLETED",
+  abgeschlossen: "COMPLETED",
+  watched: "COMPLETED",
+  gesehen: "COMPLETED",
+  dropped: "DROPPED",
+  abgebrochen: "DROPPED",
+  watchlist: "WATCHLIST",
+  plantowatch: "WATCHLIST",
+  merkliste: "WATCHLIST",
+};
+
+function parseStatus(value: string | undefined): EntryStatus {
+  if (!value) return "WATCHLIST";
+  return STATUS_ALIASES[value.trim().toLocaleLowerCase("de-DE")] ?? "WATCHLIST";
+}
+
+function parseType(value: string | undefined): TitleType | null {
+  const normalized = value?.trim().toLocaleLowerCase("de-DE");
+  if (!normalized) return null;
+  if (["serie", "series", "show", "tv", "tvshow"].includes(normalized)) return "SERIES";
+  if (["film", "movie", "kinofilm"].includes(normalized)) return "MOVIE";
+  return null;
+}
+
+// ---------------------------------------------------------------------------
+// CSV
+// ---------------------------------------------------------------------------
+
+/**
+ * Minimaler CSV-Leser mit Unterstützung für Anführungszeichen und
+ * eingebettete Zeilenumbrüche. Trennzeichen wird erraten (Komma oder
+ * Semikolon) — deutsche Tabellenprogramme nehmen gern das Semikolon.
+ */
+export function parseCsv(text: string): string[][] {
+  const clean = text.replace(/^/, "");
+  const firstLine = clean.split(/\r?\n/, 1)[0] ?? "";
+  const delimiter = (firstLine.match(/;/g)?.length ?? 0) > (firstLine.match(/,/g)?.length ?? 0) ? ";" : ",";
+
+  const rows: string[][] = [];
+  let row: string[] = [];
+  let field = "";
+  let quoted = false;
+
+  for (let index = 0; index < clean.length; index += 1) {
+    const char = clean[index];
+
+    if (quoted) {
+      if (char === '"') {
+        if (clean[index + 1] === '"') {
+          field += '"';
+          index += 1;
+        } else {
+          quoted = false;
+        }
+      } else {
+        field += char;
+      }
+      continue;
+    }
+
+    if (char === '"') {
+      quoted = true;
+    } else if (char === delimiter) {
+      row.push(field);
+      field = "";
+    } else if (char === "\n") {
+      row.push(field);
+      rows.push(row);
+      row = [];
+      field = "";
+    } else if (char !== "\r") {
+      field += char;
+    }
+  }
+
+  if (field.length > 0 || row.length > 0) {
+    row.push(field);
+    rows.push(row);
+  }
+
+  return rows.filter((entry) => entry.some((cell) => cell.trim().length > 0));
+}
+
+const CSV_HEADERS: Record<string, string> = {
+  titel: "title",
+  title: "title",
+  name: "title",
+  show: "title",
+  typ: "type",
+  type: "type",
+  art: "type",
+  status: "status",
+  bewertung: "rating",
+  rating: "rating",
+  score: "rating",
+  tmdb: "tmdbId",
+  tmdb_id: "tmdbId",
+  tmdbid: "tmdbId",
+  jahr: "year",
+  year: "year",
+  notiz: "notes",
+  notes: "notes",
+  kommentar: "notes",
+};
+
+/**
+ * CSV-Import.
+ *
+ * Erwartet eine Kopfzeile. Gebraucht wird nur eine Spalte mit dem Titel;
+ * Typ, Status, Bewertung, TMDB-ID und Notiz werden übernommen, wenn vorhanden.
+ */
+export async function importCsv(userId: string, text: string): Promise<ImportSummary> {
+  const summary: ImportSummary = { processed: 0, added: 0, skipped: 0, watchesAdded: 0, errors: [] };
+  const rows = parseCsv(text);
+  const header = rows.shift();
+
+  if (!header) {
+    summary.errors.push("Die Datei ist leer.");
+    return summary;
+  }
+
+  const columns = header.map(
+    (cell) => CSV_HEADERS[cell.trim().toLocaleLowerCase("de-DE").replace(/\s+/g, "_")] ?? "",
+  );
+  if (!columns.includes("title")) {
+    summary.errors.push(
+      'Es fehlt eine Titelspalte. Die Kopfzeile braucht eine Spalte „Titel" (oder „title", „name", „show").',
+    );
+    return summary;
+  }
+
+  for (const row of rows) {
+    summary.processed += 1;
+    const record: Record<string, string> = {};
+    columns.forEach((key, index) => {
+      if (key) record[key] = (row[index] ?? "").trim();
+    });
+
+    const title = record.title;
+    if (!title) {
+      summary.skipped += 1;
+      continue;
+    }
+
+    try {
+      const result = await importOne(userId, {
+        title,
+        type: parseType(record.type),
+        tmdbId: record.tmdbId ? Number.parseInt(record.tmdbId, 10) : null,
+        status: parseStatus(record.status),
+        rating: record.rating ? Number.parseInt(record.rating, 10) : null,
+        year: record.year ? Number.parseInt(record.year, 10) : null,
+        notes: record.notes || null,
+      });
+      if (result === "added") summary.added += 1;
+      else summary.skipped += 1;
+    } catch (error) {
+      summary.errors.push(`${title}: ${error instanceof Error ? error.message : "Fehler"}`);
+    }
+  }
+
+  return summary;
+}
+
+// ---------------------------------------------------------------------------
+// Trakt
+// ---------------------------------------------------------------------------
+
+type TraktEntry = {
+  type?: string;
+  show?: { title?: string; year?: number; ids?: { tmdb?: number } };
+  movie?: { title?: string; year?: number; ids?: { tmdb?: number } };
+  title?: string;
+  year?: number;
+  ids?: { tmdb?: number };
+  rating?: number;
+  listed_at?: string;
+  last_watched_at?: string;
+  watched_at?: string;
+  plays?: number;
+};
+
+/**
+ * Trakt.tv-Export.
+ *
+ * Trakt gibt je nach Ansicht unterschiedliche Formen aus (Watchlist,
+ * History, Ratings, Collection). Gemeinsam ist ihnen ein Array mit Einträgen,
+ * die entweder `show` oder `movie` tragen — genau darauf stützt sich der
+ * Import, statt ein bestimmtes Exportformat zu verlangen.
+ */
+export async function importTrakt(userId: string, json: string): Promise<ImportSummary> {
+  const summary: ImportSummary = { processed: 0, added: 0, skipped: 0, watchesAdded: 0, errors: [] };
+
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(json);
+  } catch {
+    summary.errors.push("Die Datei ist kein gültiges JSON.");
+    return summary;
+  }
+
+  // Ein Array direkt, oder ein Objekt mit Listen darin.
+  const entries: TraktEntry[] = Array.isArray(parsed)
+    ? (parsed as TraktEntry[])
+    : typeof parsed === "object" && parsed !== null
+      ? Object.values(parsed as Record<string, unknown>)
+          .filter(Array.isArray)
+          .flat() as TraktEntry[]
+      : [];
+
+  if (entries.length === 0) {
+    summary.errors.push("In der Datei stehen keine Einträge, die Flimmer versteht.");
+    return summary;
+  }
+
+  for (const entry of entries) {
+    summary.processed += 1;
+
+    const source = entry.show ?? entry.movie ?? entry;
+    const title = source.title;
+    if (!title) {
+      summary.skipped += 1;
+      continue;
+    }
+
+    const type: TitleType | null = entry.show
+      ? "SERIES"
+      : entry.movie
+        ? "MOVIE"
+        : parseType(entry.type);
+
+    // Was schon gesehen wurde, gilt als abgeschlossen; alles andere landet
+    // auf der Watchlist. Genauer geht es aus einem Export nicht hervor.
+    const watched = Boolean(entry.watched_at ?? entry.last_watched_at ?? entry.plays);
+
+    try {
+      const result = await importOne(userId, {
+        title,
+        type,
+        tmdbId: source.ids?.tmdb ?? null,
+        status: watched ? "COMPLETED" : "WATCHLIST",
+        rating: typeof entry.rating === "number" ? Math.round(entry.rating) : null,
+        year: source.year ?? null,
+        notes: null,
+      });
+      if (result === "added") summary.added += 1;
+      else summary.skipped += 1;
+    } catch (error) {
+      summary.errors.push(`${title}: ${error instanceof Error ? error.message : "Fehler"}`);
+    }
+  }
+
+  return summary;
+}
+
+// ---------------------------------------------------------------------------
+// Gemeinsamer Kern
+// ---------------------------------------------------------------------------
+
+type ImportRecord = {
+  title: string;
+  type: TitleType | null;
+  tmdbId: number | null;
+  status: EntryStatus;
+  rating: number | null;
+  year: number | null;
+  notes: string | null;
+};
+
+/**
+ * Nimmt einen einzelnen Eintrag auf.
+ *
+ * Mit TMDB-ID wird der Titel bei TMDB geholt; ohne wird im lokalen Katalog
+ * nach dem Namen gesucht und andernfalls ein manueller Eintrag angelegt.
+ * Das ist bewusst so: ein Import soll auch ohne TMDB-Schlüssel durchlaufen.
+ */
+async function importOne(userId: string, record: ImportRecord): Promise<"added" | "skipped"> {
+  let titleId: string | null = null;
+
+  if (record.tmdbId && record.type && env.tmdb.isConfigured) {
+    try {
+      const title = await ensureTitle(record.type, record.tmdbId, { region: env.tmdb.region });
+      titleId = title.id;
+    } catch {
+      // TMDB nicht erreichbar oder ID unbekannt — unten weiterversuchen.
+    }
+  }
+
+  if (!titleId) {
+    const existing = await prisma.title.findFirst({
+      where: {
+        title: { equals: record.title, mode: "insensitive" },
+        ...(record.type ? { type: record.type } : {}),
+      },
+      select: { id: true },
+    });
+    titleId = existing?.id ?? null;
+  }
+
+  if (!titleId) {
+    const created = await prisma.title.create({
+      data: {
+        type: record.type ?? "MOVIE",
+        title: record.title,
+        releaseDate: record.year ? new Date(Date.UTC(record.year, 0, 1)) : null,
+        status: "Importiert",
+        syncedAt: new Date(),
+      },
+      select: { id: true },
+    });
+    titleId = created.id;
+  }
+
+  const existingEntry = await prisma.libraryEntry.findUnique({
+    where: { userId_titleId: { userId, titleId } },
+    select: { id: true },
+  });
+  if (existingEntry) return "skipped";
+
+  const entry = await addToLibrary(userId, titleId, record.status);
+
+  if (record.rating || record.notes) {
+    await prisma.libraryEntry.update({
+      where: { id: entry.id },
+      data: {
+        rating: record.rating && record.rating >= 1 && record.rating <= 10 ? record.rating : null,
+        notes: record.notes,
+      },
+    });
+  }
+
+  return "added";
+}
+
+// ---------------------------------------------------------------------------
+// Export
+// ---------------------------------------------------------------------------
+
+function csvCell(value: unknown): string {
+  const text = value === null || value === undefined ? "" : String(value);
+  return /[",;\n]/.test(text) ? `"${text.replace(/"/g, '""')}"` : text;
+}
+
+/** Bibliothek als CSV — ein Titel je Zeile. */
+export async function exportCsv(userId: string): Promise<string> {
+  const entries = await prisma.libraryEntry.findMany({
+    where: { userId, deletedAt: null },
+    orderBy: { title: { title: "asc" } },
+    include: {
+      title: true,
+      tags: { include: { tag: { select: { name: true } } } },
+    },
+  });
+
+  const header = [
+    "Titel",
+    "Typ",
+    "Jahr",
+    "TMDB",
+    "Status",
+    "Bewertung",
+    "Durchlaeufe",
+    "WoGeschaut",
+    "Tags",
+    "Notiz",
+    "Hinzugefuegt",
+    "Abgeschlossen",
+  ];
+
+  const rows = entries.map((entry) =>
+    [
+      entry.title.title,
+      entry.title.type === "SERIES" ? "Serie" : "Film",
+      entry.title.releaseDate?.getFullYear() ?? "",
+      entry.title.tmdbId ?? "",
+      entry.status,
+      entry.rating ?? "",
+      entry.currentRun + 1,
+      entry.whereToWatch ?? "",
+      entry.tags.map((link) => link.tag.name).join(" "),
+      entry.notes?.replace(/\r?\n/g, " ") ?? "",
+      entry.createdAt.toISOString().slice(0, 10),
+      entry.finishedAt?.toISOString().slice(0, 10) ?? "",
+    ]
+      .map(csvCell)
+      .join(","),
+  );
+
+  return [header.join(","), ...rows].join("\n");
+}
+
+/** Vollständiger Export als JSON, inklusive Sichtungen und Universen. */
+export async function exportJson(userId: string): Promise<object> {
+  const [user, entries, watches, universes] = await Promise.all([
+    prisma.user.findUniqueOrThrow({
+      where: { id: userId },
+      select: { email: true, name: true, region: true, createdAt: true },
+    }),
+    prisma.libraryEntry.findMany({
+      where: { userId, deletedAt: null },
+      include: {
+        title: {
+          select: {
+            title: true,
+            type: true,
+            tmdbId: true,
+            imdbId: true,
+            releaseDate: true,
+            genres: true,
+          },
+        },
+        tags: { include: { tag: { select: { name: true } } } },
+      },
+    }),
+    prisma.watch.findMany({
+      where: { userId },
+      orderBy: { watchedAt: "asc" },
+      include: {
+        title: { select: { title: true, tmdbId: true, type: true } },
+        episode: { select: { seasonNumber: true, episodeNumber: true, name: true } },
+      },
+    }),
+    prisma.universe.findMany({
+      where: { ownerId: userId, deletedAt: null },
+      include: {
+        items: { include: { title: { select: { title: true, tmdbId: true, type: true } } } },
+        orders: { include: { items: { orderBy: { position: "asc" } } } },
+      },
+    }),
+  ]);
+
+  return {
+    format: "flimmer-export",
+    version: 1,
+    exportedAt: new Date().toISOString(),
+    user,
+    library: entries.map((entry) => ({
+      title: entry.title.title,
+      type: entry.title.type,
+      tmdbId: entry.title.tmdbId,
+      imdbId: entry.title.imdbId,
+      year: entry.title.releaseDate?.getFullYear() ?? null,
+      genres: entry.title.genres,
+      status: entry.status,
+      rating: entry.rating,
+      notes: entry.notes,
+      whereToWatch: entry.whereToWatch,
+      favorite: entry.favorite,
+      currentRun: entry.currentRun,
+      tags: entry.tags.map((link) => link.tag.name),
+      startedAt: entry.startedAt,
+      finishedAt: entry.finishedAt,
+      createdAt: entry.createdAt,
+    })),
+    watches: watches.map((watch) => ({
+      title: watch.title.title,
+      tmdbId: watch.title.tmdbId,
+      type: watch.title.type,
+      episode: watch.episode
+        ? episodeCode(watch.episode.seasonNumber, watch.episode.episodeNumber)
+        : null,
+      episodeName: watch.episode?.name ?? null,
+      run: watch.run,
+      watchedAt: watch.watchedAt,
+      minutes: watch.minutes,
+    })),
+    universes: universes.map((universe) => ({
+      name: universe.name,
+      description: universe.description,
+      titles: universe.items.map((item) => ({
+        title: item.title.title,
+        tmdbId: item.title.tmdbId,
+        type: item.title.type,
+      })),
+      orders: universe.orders.map((order) => ({
+        name: order.name,
+        kind: order.kind,
+        positions: order.items.map((entry) => entry.position),
+      })),
+    })),
+  };
+}