diff --git a/packages/content_sync/hms_content_sync/__init__.py b/packages/content_sync/hms_content_sync/__init__.py
new file mode 100644
index 0000000..638a0f9
--- /dev/null
+++ b/packages/content_sync/hms_content_sync/__init__.py
@@ -0,0 +1,17 @@
+"""hms_content_sync – Content-Manifest und Sync-Basis (§6.4, §10.1)."""
+
+from hms_content_sync.manifest import (
+    CHUNK_SIZE,
+    ContentManifest,
+    ManifestDiff,
+    ManifestEntry,
+    hash_file,
+)
+
+__all__ = [
+    "CHUNK_SIZE",
+    "ContentManifest",
+    "ManifestDiff",
+    "ManifestEntry",
+    "hash_file",
+]
diff --git a/packages/content_sync/hms_content_sync/manifest.py b/packages/content_sync/hms_content_sync/manifest.py
new file mode 100644
index 0000000..52ea4d2
--- /dev/null
+++ b/packages/content_sync/hms_content_sync/manifest.py
@@ -0,0 +1,209 @@
+"""ContentManifest (PLAN.md §10.1, §6.4).
+
+Content Sync (§6.4): SHA-256-Manifest, resumierbare Chunks, Hashprüfung,
+Staging – Ziel sind byte-identische freigegebene Inhalte auf allen Nodes.
+
+Manifest-Einträge decken Medien, Plugins und Projektdateien ab; die Art
+wird je Eintrag vermerkt, damit Preflight Plugin-API- und
+Backend-Anforderungen prüfen kann (§10.1).
+"""
+
+from __future__ import annotations
+
+import hashlib
+import os
+import uuid
+from dataclasses import dataclass, field
+from pathlib import Path, PurePosixPath
+
+CHUNK_SIZE = 4 * 1024 * 1024  # 4 MiB Standard-Chunk für Resume (§6.4)
+
+KIND_MEDIA = "media"
+KIND_PLUGIN = "plugin"
+KIND_PROJECT = "project"
+
+
+def hash_file(path: Path | str, chunk_size: int = CHUNK_SIZE) -> tuple[str, list[str]]:
+    """SHA-256 über die ganze Datei + je Chunk (resumierbar, §6.4).
+
+    Rückgabe: (file_hash_hex, [chunk_hash_hex, ...] in Dateireihenfolge).
+    """
+    if chunk_size <= 0:
+        raise ValueError("chunk_size muss positiv sein")
+    file_hash = hashlib.sha256()
+    chunk_hashes: list[str] = []
+    with open(path, "rb") as fh:
+        while True:
+            data = fh.read(chunk_size)
+            if not data:
+                break
+            chunk_hashes.append(hashlib.sha256(data).hexdigest())
+            file_hash.update(data)
+    if not chunk_hashes:  # leere Datei: ein leerer Chunk-Hash
+        chunk_hashes.append(hashlib.sha256(b"").hexdigest())
+    return file_hash.hexdigest(), chunk_hashes
+
+
+@dataclass(frozen=True)
+class ManifestEntry:
+    """Eine Datei im Manifest (§10.1): Pfad, Größe, Hash, Art."""
+
+    rel_path: str  # portabel, POSIX-relativ
+    kind: str  # media | plugin | project
+    size_bytes: int
+    sha256: str
+    chunk_hashes: tuple[str, ...] = ()
+
+    def to_dict(self) -> dict:
+        return {
+            "rel_path": self.rel_path,
+            "kind": self.kind,
+            "size_bytes": self.size_bytes,
+            "sha256": self.sha256,
+            "chunk_hashes": list(self.chunk_hashes),
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict) -> ManifestEntry:
+        return cls(
+            rel_path=data["rel_path"],
+            kind=data["kind"],
+            size_bytes=int(data["size_bytes"]),
+            sha256=data["sha256"],
+            chunk_hashes=tuple(data.get("chunk_hashes", ())),
+        )
+
+
+@dataclass(frozen=True)
+class ManifestDiff:
+    """Unterschied zweier Manifeste (Basis für Sync-Transfer, §6.4)."""
+
+    added: frozenset[str] = field(default_factory=frozenset)
+    removed: frozenset[str] = field(default_factory=frozenset)
+    changed: frozenset[str] = field(default_factory=frozenset)
+
+    @property
+    def empty(self) -> bool:
+        return not (self.added or self.removed or self.changed)
+
+
+class ContentManifest:
+    """Versioniertes Inhalts-Manifest (§10.1 ContentManifest).
+
+    - manifest_id: Instanz-ID (UUID)
+    - revision: monotone Manifest-Revision (neu bei jeder Änderung)
+    - entries: rel_path → ManifestEntry
+
+    Der Manifest-Inhalt selbst ist deterministisch (sortierte Einträge);
+    die manifest_id identifiziert den Ausgabezeitpunkt.
+    """
+
+    def __init__(
+        self,
+        manifest_id: str | None = None,
+        revision: int = 0,
+        entries: dict[str, ManifestEntry] | None = None,
+    ) -> None:
+        self.manifest_id = manifest_id or str(uuid.uuid4())
+        self.revision = revision
+        self._entries: dict[str, ManifestEntry] = dict(entries or {})
+
+    @property
+    def entries(self) -> dict[str, ManifestEntry]:
+        return dict(self._entries)
+
+    # ---------- Aufbau ----------
+
+    @classmethod
+    def build(
+        cls,
+        root: Path | str,
+        kind_of=None,
+        chunk_size: int = CHUNK_SIZE,
+        revision: int = 0,
+    ) -> ContentManifest:
+        """Baut das Manifest aus einem Verzeichnis (§6.4 SHA-256).
+
+        kind_of: callable(rel_path) → "media"|"plugin"|"project";
+        Default: alles KIND_MEDIA.
+        """
+        root_path = Path(root)
+        if not root_path.is_dir():
+            raise FileNotFoundError(f"Manifest-Root fehlt: {root_path}")
+        entries: dict[str, ManifestEntry] = {}
+        for dirpath, _dirnames, filenames in os.walk(root_path):
+            for name in sorted(filenames):
+                abs_path = Path(dirpath) / name
+                if not abs_path.is_file():
+                    continue
+                rel = abs_path.relative_to(root_path).as_posix()
+                if ".." in PurePosixPath(rel).parts:
+                    continue  # defensive: nie Traversal ins Manifest
+                file_hash, chunks = hash_file(abs_path, chunk_size=chunk_size)
+                kind = kind_of(rel) if kind_of else KIND_MEDIA
+                entries[rel] = ManifestEntry(
+                    rel_path=rel,
+                    kind=kind,
+                    size_bytes=abs_path.stat().st_size,
+                    sha256=file_hash,
+                    chunk_hashes=tuple(chunks),
+                )
+        return cls(revision=revision, entries=entries)
+
+    # ---------- Verifikation (§6.4 Hashprüfung) ----------
+
+    def verify_file(self, root: Path | str, rel_path: str) -> bool:
+        """Prüft Größe + Hash einer Datei gegen den Manifest-Eintrag."""
+        entry = self._entries.get(rel_path)
+        if entry is None:
+            return False
+        abs_path = Path(root) / rel_path
+        if not abs_path.is_file():
+            return False
+        stat = abs_path.stat()
+        if stat.st_size != entry.size_bytes:
+            return False
+        file_hash, _chunks = hash_file(abs_path)
+        return file_hash == entry.sha256
+
+    # ---------- Diff (§6.4 Sync-Basis) ----------
+
+    def diff(self, other: ContentManifest) -> ManifestDiff:
+        """Was muss von self nach other übertragen/gelöscht werden?"""
+        mine = set(self._entries)
+        theirs = set(other._entries)
+        added = frozenset(theirs - mine)
+        removed = frozenset(mine - theirs)
+        changed = frozenset(
+            rel
+            for rel in mine & theirs
+            if self._entries[rel].sha256 != other._entries[rel].sha256
+        )
+        return ManifestDiff(added=added, removed=removed, changed=changed)
+
+    # ---------- Serialisierung ----------
+
+    def to_dict(self) -> dict:
+        return {
+            "manifest_id": self.manifest_id,
+            "revision": self.revision,
+            "entries": {
+                rel: entry.to_dict()
+                for rel, entry in sorted(self._entries.items())
+            },
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict) -> ContentManifest:
+        entries = {
+            rel: ManifestEntry.from_dict(entry)
+            for rel, entry in data.get("entries", {}).items()
+        }
+        return cls(
+            manifest_id=data.get("manifest_id"),
+            revision=int(data.get("revision", 0)),
+            entries=entries,
+        )
+
+    def __len__(self) -> int:
+        return len(self._entries)
diff --git a/packages/media/hms_media/__init__.py b/packages/media/hms_media/__init__.py
new file mode 100644
index 0000000..7fdfad2
--- /dev/null
+++ b/packages/media/hms_media/__init__.py
@@ -0,0 +1,19 @@
+"""hms_media – Playback-Transport und Medienbibliothek (PLAN.md §12.5, §13)."""
+
+from hms_media.library import ImportOutcome, ImportStatus, MediaLibrary
+from hms_media.transport import (
+    PlaybackController,
+    PlaybackEvent,
+    PlaybackEventKind,
+    PreloadSlot,
+)
+
+__all__ = [
+    "PlaybackController",
+    "PlaybackEvent",
+    "PlaybackEventKind",
+    "PreloadSlot",
+    "MediaLibrary",
+    "ImportOutcome",
+    "ImportStatus",
+]
diff --git a/packages/media/hms_media/library.py b/packages/media/hms_media/library.py
new file mode 100644
index 0000000..51248fe
--- /dev/null
+++ b/packages/media/hms_media/library.py
@@ -0,0 +1,172 @@
+"""Medienbibliothek: Index, Import, Duplikate, Banken (§13.2, §13.3).
+
+Import-Regeln (§13.3):
+- Import blockiert niemals den Renderthread: der Control Core ruft diese
+  Methoden aus einem Worker-Thread/Executor auf (asyncio.to_thread).
+- Duplikate werden über den Inhalts-Hash erkannt.
+- Medienbank und Clipnummer sind explizite Show-Metadaten, nicht vom
+  Dateinamen abhängig (§13.2).
+- Fehlende Dateien werden markiert und können neu verknüpft werden.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from enum import StrEnum
+from pathlib import Path, PurePosixPath
+
+from hms_domain.model import MediaAsset
+
+
+class ImportStatus(StrEnum):
+    IMPORTED = "imported"
+    DUPLICATE = "duplicate"
+    MISSING_FILE = "missing_file"
+
+
+@dataclass(frozen=True)
+class ImportOutcome:
+    """Ergebnis eines Imports (§13.3)."""
+
+    status: ImportStatus
+    asset: MediaAsset | None
+    duplicate_of: str | None = None  # asset_id des existierenden Duplikats
+
+
+class MediaLibrary:
+    """Medienindex über portablem Media-Root (§13.2).
+
+    - Assets werden über stabile UUIDs adressiert, nie über Pfade.
+    - Duplikaterkennung über SHA-256 (Content-Hash).
+    - Bank-Registry: (bank, index) → asset_id als Show-Metadaten.
+    """
+
+    def __init__(self, media_root: Path) -> None:
+        self._media_root = Path(media_root)
+        self._assets: dict[str, MediaAsset] = {}
+        self._by_hash: dict[str, str] = {}  # content_hash → asset_id
+        self._banks: dict[tuple[int, int], str] = {}  # (bank, index) → asset_id
+        self._missing: set[str] = set()
+
+    @property
+    def media_root(self) -> Path:
+        return self._media_root
+
+    # ---------- Import (§13.3) ----------
+
+    def import_file(self, abs_path: Path | str) -> ImportOutcome:
+        """Importiert eine Datei; Duplikate werden erkannt (§13.3).
+
+        Läuft im Control Core in einem Worker-Thread; blockiert den
+        Renderthread nie (dieser Prozess hat keinen Zugriff auf die Library).
+        """
+        path = Path(abs_path)
+        if not path.is_file():
+            return ImportOutcome(status=ImportStatus.MISSING_FILE, asset=None)
+
+        from hms_content_sync.manifest import hash_file
+
+        file_hash, _chunks = hash_file(path)
+        existing_id = self._by_hash.get(file_hash)
+        if existing_id is not None:
+            return ImportOutcome(
+                status=ImportStatus.DUPLICATE,
+                asset=self._assets[existing_id],
+                duplicate_of=existing_id,
+            )
+
+        rel = self._relative_to_media_root(path)
+        stat = path.stat()
+        asset = MediaAsset(
+            rel_path=rel,
+            file_size_bytes=stat.st_size,
+            mtime_ns=stat.st_mtime_ns,
+            content_hash=file_hash,
+        )
+        self._assets[asset.id] = asset
+        self._by_hash[file_hash] = asset.id
+        self._missing.discard(asset.id)
+        return ImportOutcome(status=ImportStatus.IMPORTED, asset=asset)
+
+    # ---------- Bank-Registry (§13.2 Show-Metadaten) ----------
+
+    def register_bank_slot(self, asset_id: str, bank: int, index: int) -> None:
+        """Clipnummer/Bank als explizite Metadaten setzen (§13.2).
+
+        Nicht Dateinamen-basiert: Umbenennen der Datei ändert nichts.
+        """
+        if asset_id not in self._assets:
+            raise KeyError(f"unbekanntes Asset {asset_id}")
+        if bank < 0 or index < 0:
+            raise ValueError("bank und index müssen >= 0 sein")
+        self._banks[(bank, index)] = asset_id
+
+    def asset_at(self, bank: int, index: int) -> MediaAsset | None:
+        asset_id = self._banks.get((bank, index))
+        return self._assets.get(asset_id) if asset_id else None
+
+    # ---------- Fehlende Dateien / Relink (§13.3) ----------
+
+    def mark_missing(self) -> list[str]:
+        """Prüft Existenz aller Dateien; liefert neu fehlende asset_ids."""
+        newly_missing: list[str] = []
+        for asset in self._assets.values():
+            exists = (self._media_root / asset.rel_path).is_file()
+            if not exists and asset.id not in self._missing:
+                self._missing.add(asset.id)
+                newly_missing.append(asset.id)
+            elif exists:
+                self._missing.discard(asset.id)
+        return newly_missing
+
+    @property
+    def missing_asset_ids(self) -> frozenset[str]:
+        return frozenset(self._missing)
+
+    def relink(self, asset_id: str, new_abs_path: Path | str) -> MediaAsset:
+        """Verknüpft ein Asset mit einer neuen Datei (§13.3).
+
+        Hash wird neu bestimmt; ändert sich der Inhalt, wird der Hash
+        aktualisiert (Pfad-Referenz bleibt dieselbe Asset-ID).
+        """
+        asset = self._assets.get(asset_id)
+        if asset is None:
+            raise KeyError(f"unbekanntes Asset {asset_id}")
+        path = Path(new_abs_path)
+        if not path.is_file():
+            raise FileNotFoundError(str(path))
+        from hms_content_sync.manifest import hash_file
+
+        file_hash, _chunks = hash_file(path)
+        rel = self._relative_to_media_root(path)
+        stat = path.stat()
+        updated = asset.model_copy(
+            update={
+                "rel_path": rel,
+                "file_size_bytes": stat.st_size,
+                "mtime_ns": stat.st_mtime_ns,
+                "content_hash": file_hash,
+            }
+        )
+        self._assets[asset_id] = updated
+        self._by_hash[file_hash] = asset_id
+        self._missing.discard(asset_id)
+        return updated
+
+    # ---------- Abfragen ----------
+
+    def get(self, asset_id: str) -> MediaAsset | None:
+        return self._assets.get(asset_id)
+
+    def all(self) -> list[MediaAsset]:
+        return list(self._assets.values())
+
+    def __len__(self) -> int:
+        return len(self._assets)
+
+    # ---------- Interna ----------
+
+    def _relative_to_media_root(self, path: Path) -> str:
+        rel = path.resolve().relative_to(self._media_root.resolve())
+        posix = PurePosixPath(*rel.parts).as_posix()
+        return posix
diff --git a/packages/media/hms_media/transport.py b/packages/media/hms_media/transport.py
new file mode 100644
index 0000000..911f309
--- /dev/null
+++ b/packages/media/hms_media/transport.py
@@ -0,0 +1,196 @@
+"""Playback-Transportmodell und atomarer Clipwechsel (§12.2, §12.5).
+
+Reine Steuerungslogik ohne Pixelverarbeitung (§33): Positions-, Loop- und
+Trigger-Berechnung sind plattformneutral und werden vom Renderer pro Frame
+ausgeführt. Ping-Pong ist modellseitig verfügbar – ob ein Medium es
+performant kann, entscheidet die Codec-Eignung (MediaAsset.seek_suitability,
+§12.5); ungeeignete Medien werden sichtbar gemeldet, nicht still verlangsamt.
+"""
+
+from __future__ import annotations
+
+import time
+from dataclasses import dataclass
+from enum import StrEnum
+
+from hms_domain.model import LoopMode, TransportState
+
+
+class PlaybackEventKind(StrEnum):
+    """Ereignisse je Advancement-Schritt (§12.5 Ende-Ereignis)."""
+
+    END_OF_MEDIA = "end_of_media"
+    LOOP_WRAP = "loop_wrap"
+    DIRECTION_CHANGE = "direction_change"
+
+
+@dataclass(frozen=True)
+class PlaybackEvent:
+    """Ein Wiedergabe-Ereignis mit Position und monotone Zeit."""
+
+    kind: PlaybackEventKind
+    source_id: str
+    position: float
+    monotonic_ns: int
+
+
+class PlaybackController:
+    """Transport-Zustandsmaschine für genau eine Quelle (§12.5).
+
+    - play/pause/stop/retrigger
+    - Position normalisiert 0..1, In-/Out-Punkte aus Source (§10.1)
+    - Loop, Once, Ping-Pong
+    - variable Geschwindigkeit; negativ = rückwärts
+    - advance(dt) liefert Ereignisse; Medienende genau einmal je Pass
+
+    Kein interner Timer: der Renderer ruft advance(dt) pro Frame mit der
+    gemeinsamen monotonen Zeitbasis (§12.2) auf.
+    """
+
+    def __init__(
+        self,
+        source_id: str,
+        in_point: float = 0.0,
+        out_point: float = 1.0,
+        loop_mode: LoopMode = LoopMode.LOOP,
+        speed: float = 1.0,
+    ) -> None:
+        if not 0.0 <= in_point < out_point <= 1.0:
+            raise ValueError("in_point muss kleiner als out_point im Bereich 0..1 sein")
+        self.source_id = source_id
+        self.in_point = in_point
+        self.out_point = out_point
+        self.loop_mode = loop_mode
+        self.state = TransportState.STOPPED
+        self.position = in_point
+        self.direction = 1  # +1 vorwärts, -1 rückwärts (Ping-Pong)
+        self.speed = speed
+
+    # ---------- Transportbefehle (§12.5) ----------
+
+    def play(self) -> None:
+        self.state = TransportState.PLAYING
+
+    def pause(self) -> None:
+        if self.state is TransportState.PLAYING:
+            self.state = TransportState.PAUSED
+
+    def stop(self) -> None:
+        """Stop: Transport angehalten, Position zurück auf In-Point."""
+        self.state = TransportState.STOPPED
+        self.position = self.in_point
+        self.direction = 1
+
+    def retrigger(self) -> None:
+        """Neustart ab In-Point (flankenbasiert getriggert, §16.5)."""
+        self.position = self.in_point
+        self.direction = 1
+        self.state = TransportState.PLAYING
+
+    def seek(self, position: float) -> None:
+        if not self.in_point <= position <= self.out_point:
+            raise ValueError(f"seek außerhalb In/Out: {position}")
+        self.position = position
+
+    def set_speed(self, speed: float) -> None:
+        if speed == 0.0:
+            raise ValueError("speed 0 unzulässig; pause() verwenden")
+        self.speed = speed
+
+    # ---------- Frame-Advancement ----------
+
+    def advance(self, dt_s: float, now_ns: int | None = None) -> list[PlaybackEvent]:
+        """Advancement um dt Sekunden; liefert Ereignisse dieses Schritts.
+
+        Wird nur im PLAYING-Zustand wirksam. Grenzüberschreitungen werden
+        gemäß Loop-Modus behandelt; die Position bleibt immer innerhalb
+        [in_point, out_point].
+        """
+        if dt_s < 0.0:
+            raise ValueError("dt_s darf nicht negativ sein")
+        if self.state is not TransportState.PLAYING or dt_s == 0.0:
+            return []
+        now = now_ns if now_ns is not None else time.monotonic_ns()
+        events: list[PlaybackEvent] = []
+        span = self.out_point - self.in_point
+        new_pos = self.position + self.direction * self.speed * dt_s
+
+        if self.loop_mode is LoopMode.LOOP:
+            if new_pos > self.out_point:
+                new_pos = self.in_point + (new_pos - self.out_point) % span
+                events.append(self._event(PlaybackEventKind.LOOP_WRAP, new_pos, now))
+            elif new_pos < self.in_point:
+                overshoot = (self.in_point - new_pos) % span
+                new_pos = self.out_point - overshoot if overshoot else self.in_point
+                events.append(self._event(PlaybackEventKind.LOOP_WRAP, new_pos, now))
+        elif self.loop_mode is LoopMode.ONCE:
+            if new_pos >= self.out_point or new_pos <= self.in_point:
+                new_pos = self.out_point if self.direction > 0 else self.in_point
+                self.state = TransportState.STOPPED
+                events.append(self._event(PlaybackEventKind.END_OF_MEDIA, new_pos, now))
+        else:  # PING_PONG
+            if self.direction > 0 and new_pos >= self.out_point:
+                new_pos = max(self.out_point - (new_pos - self.out_point), self.in_point)
+                self.direction = -1
+                events.append(self._event(PlaybackEventKind.DIRECTION_CHANGE, new_pos, now))
+            elif self.direction < 0 and new_pos <= self.in_point:
+                new_pos = min(self.in_point + (self.in_point - new_pos), self.out_point)
+                self.direction = 1
+                events.append(self._event(PlaybackEventKind.DIRECTION_CHANGE, new_pos, now))
+
+        self.position = new_pos
+        return events
+
+    def _event(
+        self, kind: PlaybackEventKind, position: float, now_ns: int
+    ) -> PlaybackEvent:
+        return PlaybackEvent(
+            kind=kind,
+            source_id=self.source_id,
+            position=position,
+            monotonic_ns=now_ns,
+        )
+
+
+class PreloadSlot:
+    """Vorgepufferte, atomar umschaltbare Clipauswahl (§12.2, §16.5).
+
+    Ablauf: preload() → Renderer bereitet Decoder vor → mark_ready() →
+    commit() wechselt an der Framegrenze atomar um. Ist beim Commit nicht
+    ready, bleibt das alte Bild aktiv (Policy des Aufrufers: halten/warten/
+    Fallback, §18.3) – niemals ein halb geladenes Medium.
+    """
+
+    def __init__(self) -> None:
+        self._pending: str | None = None  # asset_id
+        self._ready: bool = False
+
+    @property
+    def pending(self) -> str | None:
+        return self._pending
+
+    @property
+    def ready(self) -> bool:
+        return self._ready
+
+    def preload(self, asset_id: str) -> None:
+        self._pending = asset_id
+        self._ready = False
+
+    def mark_ready(self, asset_id: str) -> None:
+        if asset_id != self._pending:
+            raise ValueError("mark_ready für anderes Asset als pending")
+        self._ready = True
+
+    def commit(self) -> str | None:
+        """Atomarer Wechsel: gibt das Asset zurück oder None (nicht bereit)."""
+        if self._pending is not None and self._ready:
+            asset_id = self._pending
+            self._pending = None
+            self._ready = False
+            return asset_id
+        return None
+
+    def cancel(self) -> None:
+        self._pending = None
+        self._ready = False
diff --git a/pyproject.toml b/pyproject.toml
index 8d237e3..c0500e1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -32,6 +32,8 @@ packages = [
     "packages/plugin_sdk/hms_plugin_sdk",
     "packages/persistence/hms_persistence",
     "packages/cluster/hms_cluster",
+    "packages/media/hms_media",
+    "packages/content_sync/hms_content_sync",
     "apps/renderer/hms_renderer",
     "apps/control_server/hms_control_server",
     "apps/launcher/hms_launcher",
diff --git a/tests/conftest.py b/tests/conftest.py
index 237c53f..d8dbeb4 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -21,6 +21,8 @@ _PACKAGE_DIRS = [
     "packages/plugin_sdk",
     "packages/persistence",
     "packages/cluster",
+    "packages/media",
+    "packages/content_sync",
     "apps/renderer",
     "apps/control_server",
     "apps/launcher",
diff --git a/tests/unit/test_content_manifest.py b/tests/unit/test_content_manifest.py
new file mode 100644
index 0000000..56da715
--- /dev/null
+++ b/tests/unit/test_content_manifest.py
@@ -0,0 +1,119 @@
+"""Unit-Tests Content-Manifest (PLAN.md §6.4, §10.1, §29.1).
+
+Manifest-Chunks/-Hashes, Diff für Sync, Verifikation gegen Fälschung
+und Rundreise – Grundlage für Preflight und resumierbare Übertragung.
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import pytest
+from hms_content_sync import CHUNK_SIZE, ContentManifest, hash_file
+
+
+@pytest.fixture()
+def content_tree(tmp_path: Path) -> Path:
+    root = tmp_path / "content"
+    (root / "clips").mkdir(parents=True)
+    (root / "clips" / "intro.mp4").write_bytes(b"A" * 1000)
+    (root / "clips" / "loop.mp4").write_bytes(b"B" * 500)
+    (root / "presets").mkdir()
+    (root / "presets" / "look.json").write_text("{}", encoding="utf-8")
+    return root
+
+
+def test_hash_file_chunks_match_content(tmp_path: Path) -> None:
+    f = tmp_path / "f.bin"
+    f.write_bytes(b"x" * (CHUNK_SIZE + 100))  # > 1 Chunk
+    file_hash, chunks = hash_file(f)
+    assert len(chunks) == 2  # voller + Rest-Chunk
+    assert len(file_hash) == 64  # SHA-256 Hex
+
+
+def test_hash_file_empty_file_yields_empty_chunk(tmp_path: Path) -> None:
+    f = tmp_path / "empty.bin"
+    f.write_bytes(b"")
+    file_hash, chunks = hash_file(f)
+    assert len(chunks) == 1
+    assert file_hash  # auch leere Dateien haben einen definierten Hash
+
+
+def test_manifest_build_covers_all_files(content_tree: Path) -> None:
+    manifest = ContentManifest.build(content_tree, revision=7)
+    assert len(manifest) == 3
+    assert manifest.revision == 7
+    assert "clips/intro.mp4" in manifest.entries
+    assert "presets/look.json" in manifest.entries
+    entry = manifest.entries["clips/intro.mp4"]
+    assert entry.size_bytes == 1000
+    assert len(entry.sha256) == 64
+    assert entry.kind == "media"  # Default-Art
+
+
+def test_manifest_kind_classification(content_tree: Path) -> None:
+    manifest = ContentManifest.build(
+        content_tree,
+        kind_of=lambda rel: "plugin" if rel.endswith(".json") else "media",
+    )
+    assert manifest.entries["presets/look.json"].kind == "plugin"
+    assert manifest.entries["clips/intro.mp4"].kind == "media"
+
+
+def test_manifest_roundtrip_preserves_entries(content_tree: Path) -> None:
+    manifest = ContentManifest.build(content_tree, revision=3)
+    restored = ContentManifest.from_dict(json.loads(json.dumps(manifest.to_dict())))
+    assert restored.revision == 3
+    assert set(restored.entries) == set(manifest.entries)
+    orig = manifest.entries["clips/intro.mp4"]
+    copy = restored.entries["clips/intro.mp4"]
+    assert copy.sha256 == orig.sha256
+    assert copy.chunk_hashes == orig.chunk_hashes
+
+
+def test_manifest_is_deterministic_across_builds(content_tree: Path) -> None:
+    """Gleicher Inhalt → gleiche Einträge (nur manifest_id ist neu)."""
+    a = ContentManifest.build(content_tree)
+    b = ContentManifest.build(content_tree)
+    assert a.to_dict()["entries"] == b.to_dict()["entries"]
+    assert a.manifest_id != b.manifest_id  # Instanz-ID ist zeitlich unique
+
+
+def test_verify_detects_tampered_file(content_tree: Path) -> None:
+    manifest = ContentManifest.build(content_tree)
+    assert manifest.verify_file(content_tree, "clips/intro.mp4")
+    (content_tree / "clips" / "intro.mp4").write_bytes(b"TAMPERED" * 50)
+    assert not manifest.verify_file(content_tree, "clips/intro.mp4")  # §6.4 Hashprüfung
+
+
+def test_verify_detects_missing_and_unknown(content_tree: Path) -> None:
+    manifest = ContentManifest.build(content_tree)
+    (content_tree / "clips" / "loop.mp4").unlink()
+    assert not manifest.verify_file(content_tree, "clips/loop.mp4")
+    assert not manifest.verify_file(content_tree, "gibts/nicht.mp4")
+
+
+def test_diff_drives_sync_plan(content_tree: Path) -> None:
+    """Diff liefert exakt die Übertragungsliste (§6.4: added/removed/changed)."""
+    old = ContentManifest.build(content_tree, revision=1)
+    # Ändern + Hinzufügen + Entfernen
+    (content_tree / "clips" / "intro.mp4").write_bytes(b"GEAENDERT")
+    (content_tree / "clips" / "neu.mp4").write_bytes(b"N")
+    (content_tree / "clips" / "loop.mp4").unlink()
+    new = ContentManifest.build(content_tree, revision=2)
+
+    diff = old.diff(new)
+    assert diff.added == frozenset({"clips/neu.mp4"})
+    assert diff.removed == frozenset({"clips/loop.mp4"})
+    assert diff.changed == frozenset({"clips/intro.mp4"})
+    assert not diff.empty
+
+    # identische Manifeste: leerer Diff
+    same = old.diff(ContentManifest.from_dict(old.to_dict()))
+    assert same.empty
+
+
+def test_build_rejects_missing_root(tmp_path: Path) -> None:
+    with pytest.raises(FileNotFoundError):
+        ContentManifest.build(tmp_path / "gibts-nicht")
diff --git a/tests/unit/test_media_library.py b/tests/unit/test_media_library.py
new file mode 100644
index 0000000..0bb5238
--- /dev/null
+++ b/tests/unit/test_media_library.py
@@ -0,0 +1,89 @@
+"""Unit-Tests Medienbibliothek (PLAN.md §13.2, §13.3)."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+from hms_media import ImportStatus, MediaLibrary
+
+
+@pytest.fixture()
+def media_root(tmp_path: Path) -> Path:
+    root = tmp_path / "media"
+    (root / "clips").mkdir(parents=True)
+    (root / "clips" / "intro.mp4").write_bytes(b"video-bytes-1" * 20)
+    (root / "clips" / "loop.mp4").write_bytes(b"video-bytes-2" * 20)
+    return root
+
+
+def test_import_creates_asset_with_hash(media_root: Path) -> None:
+    lib = MediaLibrary(media_root)
+    outcome = lib.import_file(media_root / "clips" / "intro.mp4")
+    assert outcome.status is ImportStatus.IMPORTED
+    assert outcome.asset is not None
+    assert outcome.asset.content_hash  # §13.2: Hash vorhanden
+    assert outcome.asset.rel_path == "clips/intro.mp4"
+    assert len(lib) == 1
+
+
+def test_duplicate_content_detected(media_root: Path) -> None:
+    """Gleicher Inhalt unter anderem Namen = Duplikat (§13.3)."""
+    lib = MediaLibrary(media_root)
+    first = lib.import_file(media_root / "clips" / "intro.mp4")
+    copy = media_root / "clips" / "kopie.mp4"
+    copy.write_bytes((media_root / "clips" / "intro.mp4").read_bytes())
+    outcome = lib.import_file(copy)
+    assert outcome.status is ImportStatus.DUPLICATE
+    assert outcome.duplicate_of == first.asset.id  # verweist auf das Original
+    assert len(lib) == 1  # kein zweiter Eintrag
+
+
+def test_import_missing_file_reports_cleanly(media_root: Path) -> None:
+    lib = MediaLibrary(media_root)
+    outcome = lib.import_file(media_root / "clips" / "fehlt.mp4")
+    assert outcome.status is ImportStatus.MISSING_FILE
+    assert outcome.asset is None
+
+
+def test_bank_slots_are_explicit_metadata(media_root: Path) -> None:
+    """Bank/Index als Show-Metadaten, unabhängig vom Dateinamen (§13.2)."""
+    lib = MediaLibrary(media_root)
+    asset = lib.import_file(media_root / "clips" / "intro.mp4").asset
+    lib.register_bank_slot(asset.id, bank=1, index=5)
+    found = lib.asset_at(bank=1, index=5)
+    assert found is not None and found.id == asset.id
+    assert lib.asset_at(bank=1, index=6) is None
+    with pytest.raises(KeyError):
+        lib.register_bank_slot("unbekannt", 1, 1)
+
+
+def test_missing_detection_and_relink(media_root: Path) -> None:
+    """Fehlende Dateien werden markiert; Relink bindet neu (§13.3)."""
+    lib = MediaLibrary(media_root)
+    asset = lib.import_file(media_root / "clips" / "loop.mp4").asset
+    (media_root / "clips" / "loop.mp4").unlink()  # Datei verschwindet
+    assert lib.mark_missing() == [asset.id]
+    assert asset.id in lib.missing_asset_ids
+
+    # Relink auf eine neue Datei mit gleichem Namen
+    (media_root / "clips" / "loop.mp4").write_bytes(b"neuer-inhalt")
+    updated = lib.relink(asset.id, media_root / "clips" / "loop.mp4")
+    assert updated.content_hash != asset.content_hash  # neuer Inhalt → neuer Hash
+    assert asset.id not in lib.missing_asset_ids
+
+
+def test_relink_rejects_missing_target(media_root: Path) -> None:
+    lib = MediaLibrary(media_root)
+    asset = lib.import_file(media_root / "clips" / "loop.mp4").asset
+    with pytest.raises(FileNotFoundError):
+        lib.relink(asset.id, media_root / "nirgendwo.mp4")
+
+
+def test_library_all_and_get(media_root: Path) -> None:
+    lib = MediaLibrary(media_root)
+    a = lib.import_file(media_root / "clips" / "intro.mp4").asset
+    b = lib.import_file(media_root / "clips" / "loop.mp4").asset
+    assert {x.id for x in lib.all()} == {a.id, b.id}
+    assert lib.get(a.id).rel_path == "clips/intro.mp4"
+    assert lib.get("gibts-nicht") is None
diff --git a/tests/unit/test_playback.py b/tests/unit/test_playback.py
new file mode 100644
index 0000000..50d8d76
--- /dev/null
+++ b/tests/unit/test_playback.py
@@ -0,0 +1,203 @@
+"""Unit-Tests Playback-Transport (PLAN.md §12.2, §12.5, §16.6)."""
+
+from __future__ import annotations
+
+import pytest
+from hms_domain import LoopMode, TransportState
+from hms_media import PlaybackController, PlaybackEventKind, PreloadSlot
+
+
+def _controller(**overrides) -> PlaybackController:
+    defaults = dict(
+        source_id="src-1",
+        in_point=0.0,
+        out_point=1.0,
+        loop_mode=LoopMode.LOOP,
+        speed=1.0,
+    )
+    defaults.update(overrides)
+    return PlaybackController(**defaults)
+
+
+# ---------- Konstruktion und Invarianten ----------
+
+
+def test_rejects_invalid_in_out_points() -> None:
+    with pytest.raises(ValueError, match="in_point"):
+        _controller(in_point=0.9, out_point=0.1)
+    with pytest.raises(ValueError, match="in_point"):
+        _controller(in_point=0.5, out_point=0.5)
+
+
+def test_initial_state_stopped_at_in_point() -> None:
+    c = _controller(in_point=0.2)
+    assert c.state is TransportState.STOPPED
+    assert c.position == pytest.approx(0.2)
+
+
+# ---------- Transportbefehle (§12.5) ----------
+
+
+def test_play_pause_resume_cycle() -> None:
+    c = _controller()
+    c.play()
+    c.advance(0.1)
+    pos_after_play = c.position
+    c.pause()
+    assert c.state is TransportState.PAUSED
+    events = c.advance(1.0)  # pausiert: keine Bewegung
+    assert events == []
+    assert c.position == pytest.approx(pos_after_play)
+    c.play()
+    c.advance(0.1)
+    assert c.position > pos_after_play
+
+
+def test_stop_resets_position_and_direction() -> None:
+    c = _controller(in_point=0.1)
+    c.play()
+    c.advance(0.3)
+    c.stop()
+    assert c.state is TransportState.STOPPED
+    assert c.position == pytest.approx(0.1)
+    assert c.direction == 1
+
+
+def test_retrigger_restarts_from_in_point() -> None:
+    c = _controller()
+    c.play()
+    c.advance(0.4)
+    c.retrigger()  # §16.5: flankenbasierter Neustart
+    assert c.position == pytest.approx(0.0)
+    assert c.state is TransportState.PLAYING
+
+
+def test_seek_bounds_enforced() -> None:
+    c = _controller(in_point=0.2, out_point=0.8)
+    c.seek(0.5)
+    assert c.position == pytest.approx(0.5)
+    with pytest.raises(ValueError, match="In/Out"):
+        c.seek(0.9)
+    with pytest.raises(ValueError, match="In/Out"):
+        c.seek(0.1)
+
+
+def test_speed_zero_rejected_pause_is_the_way() -> None:
+    c = _controller()
+    with pytest.raises(ValueError, match="speed 0"):
+        c.set_speed(0.0)
+
+
+def test_negative_speed_plays_backward() -> None:
+    """§16.6: negative Geschwindigkeit zugelassen; Rückwärts am In-Point
+    wrappt im Loop-Modus korrekt ans Ende des Fensters (§12.5)."""
+    c = _controller()
+    c.play()
+    c.set_speed(-1.0)
+    events = c.advance(0.05)
+    assert c.position == pytest.approx(0.95)  # Wrap nach hinten: out - 0.05
+    assert events and events[0].kind is PlaybackEventKind.LOOP_WRAP
+    # danach läuft es weiter rückwärts Richtung In-Point
+    c.advance(0.05)
+    assert c.position == pytest.approx(0.9)
+
+
+# ---------- Loop-Verhalten ----------
+
+
+def test_loop_wraps_with_event() -> None:
+    c = _controller(out_point=1.0)
+    c.play()
+    events = c.advance(1.25)  # über das Ende hinaus
+    assert c.position == pytest.approx(0.25)  # Wrap: Überschuss am Anfang
+    assert events and events[0].kind is PlaybackEventKind.LOOP_WRAP
+    assert c.state is TransportState.PLAYING  # Loop läuft weiter
+
+
+def test_once_stops_at_out_point_with_end_event() -> None:
+    c = _controller(loop_mode=LoopMode.ONCE)
+    c.play()
+    events = c.advance(0.5)
+    assert events == []  # noch nicht am Ende
+    events = c.advance(0.6)  # über das Ende hinaus
+    assert c.state is TransportState.STOPPED  # §12.5: Ende-Ereignis
+    assert c.position == pytest.approx(1.0)
+    assert events and events[0].kind is PlaybackEventKind.END_OF_MEDIA
+    # weiteres Advancement bleibt gestoppt
+    assert c.advance(0.1) == []
+
+
+def test_ping_pong_reverses_direction() -> None:
+    c = _controller(loop_mode=LoopMode.PING_PONG)
+    c.play()
+    events = c.advance(1.2)  # Ende erreicht → Richtungsumkehr
+    assert c.direction == -1
+    assert c.position == pytest.approx(0.8)  # 0.2 zurückgeprallt
+    assert events and events[0].kind is PlaybackEventKind.DIRECTION_CHANGE
+    events = c.advance(1.6)  # zurück zum Anfang → wieder vorwärts
+    assert c.direction == 1
+    assert events and events[0].kind is PlaybackEventKind.DIRECTION_CHANGE
+    assert c.state is TransportState.PLAYING  # Ping-Pong läuft endlos
+
+
+def test_in_out_window_respected() -> None:
+    """Loop beachtet In/Out-Fenster, nicht nur 0..1 (§12.5)."""
+    c = _controller(in_point=0.2, out_point=0.8)
+    c.play()
+    c.advance(0.7)  # 0.2 + 0.7 = 0.9 > out 0.8
+    assert c.position == pytest.approx(0.3)  # Wrap innerhalb des Fensters
+
+
+def test_advance_rejects_negative_dt() -> None:
+    c = _controller()
+    c.play()
+    with pytest.raises(ValueError, match="negativ"):
+        c.advance(-0.1)
+
+
+def test_events_carry_source_and_monotonic_time() -> None:
+    c = _controller()
+    c.play()
+    events = c.advance(1.5, now_ns=123456789)
+    assert events[0].source_id == "src-1"
+    assert events[0].monotonic_ns == 123456789
+
+
+# ---------- PreloadSlot: atomarer Clipwechsel (§12.2, §16.5) ----------
+
+
+def test_preload_commit_atomic_flow() -> None:
+    slot = PreloadSlot()
+    assert slot.commit() is None  # nichts geladen → kein Wechsel
+    slot.preload("asset-a")
+    assert slot.pending == "asset-a"
+    assert slot.commit() is None  # noch nicht bereit → alter Clip bleibt
+    slot.mark_ready("asset-a")
+    assert slot.commit() == "asset-a"  # atomar umgeschaltet
+    assert slot.pending is None
+    assert slot.commit() is None  # Slot ist wieder leer
+
+
+def test_preload_cancel_discards() -> None:
+    slot = PreloadSlot()
+    slot.preload("asset-a")
+    slot.mark_ready("asset-a")
+    slot.cancel()
+    assert slot.pending is None
+    assert slot.commit() is None  # abgebrochen wird nie committed
+
+
+def test_preload_rejects_foreign_ready() -> None:
+    slot = PreloadSlot()
+    slot.preload("asset-a")
+    with pytest.raises(ValueError, match="anderes Asset"):
+        slot.mark_ready("asset-b")
+
+
+def test_preload_new_preload_resets_ready() -> None:
+    slot = PreloadSlot()
+    slot.preload("asset-a")
+    slot.mark_ready("asset-a")
+    slot.preload("asset-b")  # umgeladen: a wird verworfen
+    assert slot.ready is False
+    assert slot.commit() is None