diff --git a/.gitignore b/.gitignore
index b20acb3..690c692 100644
--- a/.gitignore
+++ b/.gitignore
@@ -29,3 +29,19 @@ Thumbs.db
 
 # Logs
 *.log
+
+# Testing
+.pytest_cache/
+.coverage
+.coverage.*
+htmlcov/
+coverage.xml
+*.cover
+.hypothesis/
+
+# Project data
+data/
+favorites.json
+*.db
+*.sqlite
+ohm_streaming.db
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 0000000..9ef17a1
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,71 @@
+[pytest]
+# Pytest configuration for Ohm Stream Downloader
+
+# Test discovery patterns
+python_files = test_*.py
+python_classes = Test*
+python_functions = test_*
+
+# Test paths
+testpaths = tests
+
+# Output options
+addopts =
+    # Verbose output
+    -v
+    # Show local variables in tracebacks
+    --showlocals
+    # Show summary of all test outcomes
+    -ra
+    # Strict markers
+    --strict-markers
+    # Warn about assertions that aren't being used
+    --warn=assertions
+    # Coverage reporting (if pytest-cov is installed)
+    --cov=app
+    --cov-report=term-missing
+    --cov-report=html
+    --no-cov-on-fail
+
+# Markers
+markers =
+    slow: marks tests as slow (deselect with '-m "not slow"')
+    integration: marks tests as integration tests
+    unit: marks tests as unit tests
+    asyncio: marks tests as async tests
+    network: marks tests that require network access
+
+# Ignore paths
+norecursedir = .git .tox dist build *.egg venv .venv
+
+# Logging
+log_cli = true
+log_cli_level = INFO
+log_cli_format = %(asctime)s [%(levelname)s] %(message)s
+log_cli_date_format = %Y-%m-%d %H:%M:%S
+
+# Timeout (if pytest-timeout is installed)
+timeout = 300
+
+# Asyncio mode (if pytest-asyncio is installed)
+asyncio_mode = auto
+
+# Coverage options (if pytest-cov is installed)
+[coverage:run]
+source = app
+omit =
+    */tests/*
+    */test_*.py
+    */__pycache__/*
+    */venv/*
+    */.venv/*
+
+[coverage:report]
+exclude_lines =
+    pragma: no cover
+    def __repr__
+    raise AssertionError
+    raise NotImplementedError
+    if __name__ == .__main__.:
+    if TYPE_CHECKING:
+    @abstractmethod
diff --git a/requirements.txt b/requirements.txt
index a99d129..83a68fa 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
+# Core dependencies
 fastapi==0.115.6
 uvicorn[standard]==0.32.1
 python-multipart==0.0.20
@@ -9,3 +10,11 @@ aiohttp==3.11.11
 beautifulsoup4==4.12.3
 lxml==5.3.0
 jieba==0.42.1
+
+# Testing dependencies
+pytest==8.3.4
+pytest-asyncio==0.24.0
+pytest-cov==6.0.0
+pytest-mock==3.14.0
+pytest-timeout==2.3.1
+pytest-html==4.1.1
diff --git a/tests/README.md b/tests/README.md
new file mode 100644
index 0000000..d2c0aed
--- /dev/null
+++ b/tests/README.md
@@ -0,0 +1,91 @@
+# Tests pour Ohm Stream Downloader
+
+Ce dossier contient la suite de tests unitaires pour le projet Ohm Stream Downloader.
+
+## Structure
+
+```
+tests/
+├── __init__.py              # Package initialization
+├── conftest.py              # Pytest configuration et fixtures
+├── test_models.py           # Tests pour les modèles Pydantic
+├── test_downloaders.py      # Tests pour les downloaders
+├── test_download_manager.py # Tests pour DownloadManager
+├── test_favorites.py        # Tests pour le système de favoris
+└── test_api.py              # Tests pour les endpoints FastAPI
+```
+
+## Lancer les tests
+
+### Tous les tests
+```bash
+pytest
+```
+
+### Avec couverture de code
+```bash
+pytest --cov=app --cov-report=html
+```
+
+### Uniquement les tests unitaires (rapides)
+```bash
+pytest -m "unit"
+```
+
+### Uniquement les tests d'intégration
+```bash
+pytest -m "integration"
+```
+
+### Exclure les tests lents
+```bash
+pytest -m "not slow"
+```
+
+### Mode verbeux
+```bash
+pytest -v
+```
+
+### Afficher le print debugging
+```bash
+pytest -s
+```
+
+## Fixtures disponibles
+
+Les fixtures sont définies dans `conftest.py` :
+
+- `temp_dir` : Répertoire temporaire pour les tests
+- `temp_download_dir` : Répertoire de téléchargement temporaire
+- `sample_download_task` : Exemple de tâche de téléchargement
+- `sample_download_request` : Exemple de requête de téléchargement
+- `download_manager` : Instance de DownloadManager configurée
+- `favorites_manager` : Instance de FavoritesManager configurée
+- `mock_httpx_client` : Mock pour httpx.AsyncClient
+- `sample_anime_metadata` : Exemple de métadonnées anime
+- `sample_favorite_data` : Exemple de favori
+
+## Marqueurs (Markers)
+
+Les tests sont marqués automatiquement :
+
+- `unit` : Tests unitaires (isolés, rapides)
+- `integration` : Tests d'intégration (API endpoints)
+- `asyncio` : Tests asynchrones
+- `slow` : Tests lents (à marquer manuellement)
+- `network` : Tests nécessitant un accès réseau
+
+## Couverture de code
+
+Le rapport de couverture est généré dans `htmlcov/index.html` après avoir lancé :
+```bash
+pytest --cov=app --cov-report=html
+```
+
+## Notes
+
+- Les tests utilisent des mocks pour éviter les appels réseau réels
+- Les fichiers temporaires sont nettoyés automatiquement après chaque test
+- La base de données de favoris utilise des fichiers temporaires
+- Les tests asynchrones utilisent `pytest-asyncio`
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..03b088b
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1 @@
+"""Tests package for Ohm Stream Downloader"""
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..975061c
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,56 @@
+"""
+Additional test configuration and helpers
+"""
+import asyncio
+import sys
+import os
+
+# Ensure the project root is in the Python path
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+
+
+def pytest_configure(config):
+    """Configure pytest with custom markers"""
+    config.addinivalue_line(
+        "markers", "slow: marks tests as slow (deselect with '-m \"not slow\"')"
+    )
+    config.addinivalue_line(
+        "markers", "integration: marks tests as integration tests"
+    )
+    config.addinivalue_line(
+        "markers", "unit: marks tests as unit tests"
+    )
+    config.addinivalue_line(
+        "markers", "network: marks tests that require network access"
+    )
+
+
+def pytest_collection_modifyitems(config, items):
+    """Modify test collection to add markers automatically"""
+    for item in items:
+        # Mark async tests
+        if asyncio.iscoroutinefunction(item.obj):
+            item.add_marker("asyncio")
+
+        # Mark tests in test_api.py as integration tests
+        if "test_api.py" in str(item.fspath):
+            item.add_marker("integration")
+
+        # Mark other tests as unit tests
+        else:
+            item.add_marker("unit")
+
+
+# Pytest hooks
+def pytest_report_header(config):
+    """Add custom header to pytest report"""
+    return [
+        "Ohm Stream Downloader - Test Suite",
+        f"Python: {sys.version}",
+    ]
+
+
+def pytest_html_results_table_row(report, cells):
+    """Customize HTML report (if pytest-html is installed)"""
+    if report.passed:
+        del cells[:]
diff --git a/tests/test_api.py b/tests/test_api.py
new file mode 100644
index 0000000..3de823a
--- /dev/null
+++ b/tests/test_api.py
@@ -0,0 +1,607 @@
+"""
+Unit tests for FastAPI endpoints
+"""
+import pytest
+from fastapi.testclient import TestClient
+from unittest.mock import patch, AsyncMock, Mock
+from datetime import datetime
+
+# Import the FastAPI app
+from main import app
+
+
+class TestAPIRoot:
+    """Tests for root endpoint"""
+
+    def test_root_endpoint(self):
+        """Test root endpoint returns API info"""
+        client = TestClient(app)
+        response = client.get("/")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["message"] == "Ohm Stream Downloader API"
+        assert data["status"] == "running"
+        assert "version" in data
+        assert "endpoints" in data
+
+    def test_root_endpoint_version(self):
+        """Test that API version is present"""
+        client = TestClient(app)
+        response = client.get("/")
+        data = response.json()
+        assert data["version"] in ["2.1", "2.2"]
+
+
+class TestAPIHealth:
+    """Tests for health check endpoint"""
+
+    def test_health_check(self):
+        """Test health check endpoint"""
+        client = TestClient(app)
+        response = client.get("/health")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["status"] == "healthy"
+
+
+class TestAPIProviders:
+    """Tests for providers endpoint"""
+
+    def test_providers_list(self):
+        """Test getting list of providers"""
+        client = TestClient(app)
+        response = client.get("/api/providers")
+        assert response.status_code == 200
+        data = response.json()
+        assert "providers" in data
+        assert isinstance(data["providers"], list)
+        # Check for known providers
+        provider_names = [p["id"] for p in data["providers"]]
+        assert "anime-sama" in provider_names
+        assert "neko-sama" in provider_names
+
+
+class TestAPIDownloadCreate:
+    """Tests for download creation endpoint"""
+
+    def test_create_download_success(self):
+        """Test creating a new download"""
+        client = TestClient(app)
+        response = client.post(
+            "/api/download",
+            json={"url": "https://example.com/file.mp4"}
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert "task_id" in data
+        assert "status" in data
+        assert data["status"] == "pending"
+
+    def test_create_download_with_filename(self):
+        """Test creating download with custom filename"""
+        client = TestClient(app)
+        response = client.post(
+            "/api/download",
+            json={
+                "url": "https://example.com/file.mp4",
+                "filename": "custom_name.mp4"
+            }
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert "task_id" in data
+
+    def test_create_download_invalid_url(self):
+        """Test creating download with invalid URL"""
+        client = TestClient(app)
+        response = client.post(
+            "/api/download",
+            json={"url": "not-a-valid-url"}
+        )
+        # Should return 422 for validation error
+        assert response.status_code == 422
+
+    def test_create_download_missing_url(self):
+        """Test creating download without URL"""
+        client = TestClient(app)
+        response = client.post("/api/download", json={})
+        assert response.status_code == 422
+
+
+class TestAPIDownloadList:
+    """Tests for download list endpoint"""
+
+    def test_list_downloads_empty(self):
+        """Test listing downloads when none exist"""
+        client = TestClient(app)
+        response = client.get("/api/downloads")
+        assert response.status_code == 200
+        data = response.json()
+        assert "downloads" in data
+        assert isinstance(data["downloads"], list)
+        # May or may not be empty depending on test order
+
+    def test_list_downloads_after_creation(self):
+        """Test listing downloads after creating one"""
+        client = TestClient(app)
+        # Create a download first
+        create_response = client.post(
+            "/api/download",
+            json={"url": "https://example.com/test.mp4"}
+        )
+        assert create_response.status_code == 200
+
+        # List downloads
+        response = client.get("/api/downloads")
+        assert response.status_code == 200
+        data = response.json()
+        assert len(data["downloads"]) >= 1
+
+
+class TestAPIDownloadDetails:
+    """Tests for download details endpoint"""
+
+    def test_get_download_details_success(self):
+        """Test getting details of existing download"""
+        client = TestClient(app)
+        # Create a download first
+        create_response = client.post(
+            "/api/download",
+            json={"url": "https://example.com/details.mp4"}
+        )
+        task_id = create_response.json()["task_id"]
+
+        # Get details
+        response = client.get(f"/api/download/{task_id}")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["id"] == task_id
+        assert "url" in data
+        assert "status" in data
+
+    def test_get_download_details_not_found(self):
+        """Test getting details of non-existent download"""
+        client = TestClient(app)
+        response = client.get("/api/download/nonexistent-id")
+        assert response.status_code == 404
+
+
+class TestAPIDownloadPause:
+    """Tests for pause download endpoint"""
+
+    def test_pause_download_success(self):
+        """Test pausing a download"""
+        client = TestClient(app)
+        # Create a download first
+        create_response = client.post(
+            "/api/download",
+            json={"url": "https://example.com/pause.mp4"}
+        )
+        task_id = create_response.json()["task_id"]
+
+        # Pause it
+        response = client.post(f"/api/download/{task_id}/pause")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["status"] == "paused"
+
+    def test_pause_download_not_found(self):
+        """Test pausing non-existent download"""
+        client = TestClient(app)
+        response = client.post("/api/download/nonexistent-id/pause")
+        assert response.status_code == 404
+
+
+class TestAPIDownloadResume:
+    """Tests for resume download endpoint"""
+
+    def test_resume_download_success(self):
+        """Test resuming a paused download"""
+        client = TestClient(app)
+        # Create and pause a download
+        create_response = client.post(
+            "/api/download",
+            json={"url": "https://example.com/resume.mp4"}
+        )
+        task_id = create_response.json()["task_id"]
+
+        # Pause first
+        client.post(f"/api/download/{task_id}/pause")
+
+        # Resume
+        response = client.post(f"/api/download/{task_id}/resume")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["status"] in ["pending", "downloading"]
+
+
+class TestAPIDownloadCancel:
+    """Tests for cancel download endpoint"""
+
+    def test_cancel_download_success(self):
+        """Test canceling a download"""
+        client = TestClient(app)
+        # Create a download first
+        create_response = client.post(
+            "/api/download",
+            json={"url": "https://example.com/cancel.mp4"}
+        )
+        task_id = create_response.json()["task_id"]
+
+        # Cancel it
+        response = client.delete(f"/api/download/{task_id}")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["status"] == "cancelled"
+
+    def test_cancel_download_not_found(self):
+        """Test canceling non-existent download"""
+        client = TestClient(app)
+        response = client.delete("/api/download/nonexistent-id")
+        assert response.status_code == 404
+
+
+class TestAPIAnimeSearch:
+    """Tests for anime search endpoint"""
+
+    def test_anime_search_missing_query(self):
+        """Test anime search without query parameter"""
+        client = TestClient(app)
+        response = client.get("/api/anime/search")
+        assert response.status_code == 400  # Bad request
+
+    def test_anime_search_with_query(self):
+        """Test anime search with query parameter"""
+        client = TestClient(app)
+        response = client.get("/api/anime/search?q=naruto")
+        # This will likely fail without actual network/anime sites
+        # but we're testing the endpoint exists
+        assert response.status_code in [200, 500, 503]  # Various possibilities
+
+    def test_anime_search_with_language(self):
+        """Test anime search with language parameter"""
+        client = TestClient(app)
+        response = client.get("/api/anime/search?q=one+piece&lang=vostfr")
+        # Similar to above, testing endpoint exists
+        assert response.status_code in [200, 500, 503]
+
+    def test_anime_search_with_metadata(self):
+        """Test anime search with metadata flag"""
+        client = TestClient(app)
+        response = client.get("/api/anime/search?q=bleach&include_metadata=true")
+        # Testing endpoint accepts the parameter
+        assert response.status_code in [200, 500, 503]
+
+
+class TestAPIAnimeMetadata:
+    """Tests for anime metadata endpoint"""
+
+    def test_anime_metadata_missing_url(self):
+        """Test metadata endpoint without URL"""
+        client = TestClient(app)
+        response = client.get("/api/anime/metadata")
+        assert response.status_code == 400
+
+    def test_anime_metadata_with_url(self):
+        """Test metadata endpoint with URL"""
+        client = TestClient(app)
+        response = client.get("/api/anime/metadata?url=https://anime-sama.si/test/")
+        # Will likely fail without real anime site
+        assert response.status_code in [200, 404, 500, 503]
+
+
+class TestAPIAnimeEpisodes:
+    """Tests for anime episodes endpoint"""
+
+    def test_anime_episodes_missing_url(self):
+        """Test episodes endpoint without URL"""
+        client = TestClient(app)
+        response = client.get("/api/anime/episodes")
+        assert response.status_code == 400
+
+    def test_anime_episodes_with_url(self):
+        """Test episodes endpoint with URL"""
+        client = TestClient(app)
+        response = client.get(
+            "/api/anime/episodes?url=https://anime-sama.si/test/&lang=vostfr"
+        )
+        # Will likely fail without real anime site
+        assert response.status_code in [200, 404, 500, 503]
+
+
+class TestAPIFavorites:
+    """Tests for favorites endpoints"""
+
+    def test_list_favorites_empty(self):
+        """Test listing favorites when empty"""
+        client = TestClient(app)
+        response = client.get("/api/favorites")
+        assert response.status_code == 200
+        data = response.json()
+        assert "favorites" in data
+        assert "total" in data
+
+    def test_add_favorite_success(self):
+        """Test adding a favorite"""
+        client = TestClient(app)
+        response = client.post(
+            "/api/favorites",
+            json={
+                "anime_id": "test-anime-123",
+                "title": "Test Anime",
+                "url": "https://example.com/anime",
+                "provider": "anime-sama",
+                "metadata": {"genres": ["Action"]},
+                "poster_url": "https://example.com/poster.jpg"
+            }
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert data["status"] == "added"
+        assert "favorite" in data
+
+    def test_add_favorite_missing_fields(self):
+        """Test adding favorite with missing required fields"""
+        client = TestClient(app)
+        response = client.post(
+            "/api/favorites",
+            json={"title": "Test Anime"}  # Missing anime_id, url, provider
+        )
+        assert response.status_code == 400
+
+    def test_remove_favorite_success(self):
+        """Test removing a favorite"""
+        client = TestClient(app)
+        # Add first
+        client.post(
+            "/api/favorites",
+            json={
+                "anime_id": "test-remove-123",
+                "title": "Remove Me",
+                "url": "https://example.com",
+                "provider": "anime-sama"
+            }
+        )
+
+        # Remove
+        response = client.delete("/api/favorites/test-remove-123")
+        assert response.status_code == 200
+        data = response.json()
+        assert data["status"] == "removed"
+
+    def test_remove_favorite_not_found(self):
+        """Test removing non-existent favorite"""
+        client = TestClient(app)
+        response = client.delete("/api/favorites/nonexistent-id")
+        assert response.status_code == 404
+
+    def test_get_favorite_success(self):
+        """Test getting a specific favorite"""
+        client = TestClient(app)
+        # Add first
+        client.post(
+            "/api/favorites",
+            json={
+                "anime_id": "test-get-123",
+                "title": "Get Me",
+                "url": "https://example.com",
+                "provider": "anime-sama"
+            }
+        )
+
+        # Get
+        response = client.get("/api/favorites/test-get-123")
+        assert response.status_code == 200
+        data = response.json()
+        assert "favorite" in data
+        assert data["favorite"]["id"] == "test-get-123"
+
+    def test_get_favorite_not_found(self):
+        """Test getting non-existent favorite"""
+        client = TestClient(app)
+        response = client.get("/api/favorites/nonexistent-id")
+        assert response.status_code == 404
+
+    def test_get_favorites_stats(self):
+        """Test getting favorites statistics"""
+        client = TestClient(app)
+        response = client.get("/api/favorites/stats")
+        assert response.status_code == 200
+        data = response.json()
+        assert "total" in data
+        assert "by_provider" in data
+        assert "by_genre" in data
+
+    def test_toggle_favorite_add(self):
+        """Test toggling favorite to add"""
+        client = TestClient(app)
+        response = client.post(
+            "/api/favorites/toggle",
+            json={
+                "anime_id": "test-toggle-add",
+                "title": "Toggle Add",
+                "url": "https://example.com",
+                "provider": "anime-sama"
+            }
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert data["action"] == "added"
+
+    def test_toggle_favorite_remove(self):
+        """Test toggling favorite to remove"""
+        client = TestClient(app)
+        # Add first
+        client.post(
+            "/api/favorites/toggle",
+            json={
+                "anime_id": "test-toggle-remove",
+                "title": "Toggle Remove",
+                "url": "https://example.com",
+                "provider": "anime-sama"
+            }
+        )
+
+        # Toggle to remove
+        response = client.post(
+            "/api/favorites/toggle",
+            json={
+                "anime_id": "test-toggle-remove",
+                "title": "Toggle Remove",
+                "url": "https://example.com",
+                "provider": "anime-sama"
+            }
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert data["action"] == "removed"
+
+
+class TestAPIFavoritesSorting:
+    """Tests for favorites sorting and filtering"""
+
+    def test_favorites_sort_by_title(self):
+        """Test sorting favorites by title"""
+        client = TestClient(app)
+        # Add multiple favorites
+        for title in ["Z Anime", "A Anime", "M Anime"]:
+            client.post(
+                "/api/favorites",
+                json={
+                    "anime_id": f"sort-{title}",
+                    "title": title,
+                    "url": f"https://example.com/{title}",
+                    "provider": "anime-sama"
+                }
+            )
+
+        response = client.get("/api/favorites?sort_by=title&order=asc")
+        assert response.status_code == 200
+        data = response.json()
+        if len(data["favorites"]) > 0:
+            # Check if sorted
+            titles = [f["title"] for f in data["favorites"][:3]]
+            assert titles == sorted(titles)
+
+    def test_favorites_filter_by_provider(self):
+        """Test filtering favorites by provider"""
+        client = TestClient(app)
+        # Add favorites with different providers
+        client.post(
+            "/api/favorites",
+            json={
+                "anime_id": "filter-anime-sama",
+                "title": "Anime Sama",
+                "url": "https://example.com",
+                "provider": "anime-sama"
+            }
+        )
+        client.post(
+            "/api/favorites",
+            json={
+                "anime_id": "filter-neko-sama",
+                "title": "Neko Sama",
+                "url": "https://example.com",
+                "provider": "neko-sama"
+            }
+        )
+
+        response = client.get("/api/favorites?filter_provider=anime-sama")
+        assert response.status_code == 200
+        data = response.json()
+        # Should only have anime-sama
+        for fav in data["favorites"]:
+            assert fav["provider"] == "anime-sama"
+
+
+class TestAPIWebInterface:
+    """Tests for web interface endpoint"""
+
+    def test_web_interface(self):
+        """Test web interface endpoint"""
+        client = TestClient(app)
+        response = client.get("/web")
+        assert response.status_code == 200
+        # Should return HTML
+        assert "text/html" in response.headers["content-type"]
+
+
+class TestAPIVideoStreaming:
+    """Tests for video streaming endpoints"""
+
+    def test_video_player_by_id_not_found(self):
+        """Test video player with non-existent task ID"""
+        client = TestClient(app)
+        response = client.get("/player/nonexistent-id")
+        # Should return 404 or similar
+        assert response.status_code in [404, 403]
+
+    def test_video_stream_by_filename_not_found(self):
+        """Test video stream with non-existent filename"""
+        client = TestClient(app)
+        response = client.get("/stream/nonexistent_file.mp4")
+        # Should return 404
+        assert response.status_code == 404
+
+
+class TestAPIErrorHandling:
+    """Tests for API error handling"""
+
+    def test_invalid_endpoint(self):
+        """Test accessing invalid endpoint"""
+        client = TestClient(app)
+        response = client.get("/api/invalid_endpoint")
+        assert response.status_code == 404
+
+    def test_invalid_method(self):
+        """Test using invalid HTTP method"""
+        client = TestClient(app)
+        response = client.post("/api/downloads")  # Should be GET
+        assert response.status_code == 405  # Method Not Allowed
+
+    def test_malformed_json(self):
+        """Test sending malformed JSON"""
+        client = TestClient(app)
+        response = client.post(
+            "/api/download",
+            data="invalid json",
+            headers={"Content-Type": "application/json"}
+        )
+        assert response.status_code == 422
+
+
+class TestAPICorsHeaders:
+    """Tests for CORS headers"""
+
+    def test_cors_headers_present(self):
+        """Test that CORS headers are present"""
+        client = TestClient(app)
+        response = client.get("/")
+        # Check for CORS headers
+        # Note: Actual CORS configuration may vary
+        # This is just to ensure the endpoint responds
+        assert response.status_code == 200
+
+
+# Mock-based tests for endpoints requiring external resources
+class TestAPIWithMocks:
+    """Tests with mocked external dependencies"""
+
+    def test_download_with_mocked_downloader(self):
+        """Test download creation with mocked downloader"""
+        client = TestClient(app)
+        with patch('app.download_manager.get_downloader') as mock_get_downloader:
+            mock_downloader = AsyncMock()
+            mock_downloader.get_download_link.return_value = (
+                "https://example.com/direct",
+                "video.mp4"
+            )
+            mock_downloader.can_handle.return_value = True
+            mock_get_downloader.return_value = mock_downloader
+
+            response = client.post(
+                "/api/download",
+                json={"url": "https://doodstream.com/test"}
+            )
+            # Should succeed
+            assert response.status_code == 200
diff --git a/tests/test_download_manager.py b/tests/test_download_manager.py
new file mode 100644
index 0000000..085f266
--- /dev/null
+++ b/tests/test_download_manager.py
@@ -0,0 +1,401 @@
+"""
+Unit tests for DownloadManager
+"""
+import pytest
+import asyncio
+from pathlib import Path
+from unittest.mock import Mock, AsyncMock, patch, MagicMock
+from datetime import datetime
+
+from app.download_manager import DownloadManager
+from app.models import DownloadTask, DownloadStatus, DownloadRequest, HostType
+
+
+class TestDownloadManagerInit:
+    """Tests for DownloadManager initialization"""
+
+    def test_init_default_parameters(self, temp_download_dir):
+        """Test DownloadManager initialization with default parameters"""
+        manager = DownloadManager(download_dir=str(temp_download_dir))
+        assert manager.download_dir == temp_download_dir
+        assert manager.max_parallel == 3
+        assert manager.tasks == {}
+        assert manager.active_downloads == {}
+        assert temp_download_dir.exists()
+
+    def test_init_custom_parameters(self, temp_download_dir):
+        """Test DownloadManager initialization with custom parameters"""
+        manager = DownloadManager(
+            download_dir=str(temp_download_dir),
+            max_parallel=5
+        )
+        assert manager.max_parallel == 5
+
+    def test_init_creates_download_directory(self, temp_dir):
+        """Test that initialization creates download directory"""
+        download_dir = temp_dir / "new_downloads"
+        assert not download_dir.exists()
+
+        manager = DownloadManager(download_dir=str(download_dir))
+        assert download_dir.exists()
+        assert download_dir.is_dir()
+
+
+class TestDownloadManagerTaskCreation:
+    """Tests for task creation and management"""
+
+    def test_create_task(self, download_manager, sample_download_request):
+        """Test creating a new download task"""
+        task = download_manager.create_task(sample_download_request)
+
+        assert isinstance(task, DownloadTask)
+        assert task.url == sample_download_request.url
+        assert task.filename == sample_download_request.filename
+        assert task.status == DownloadStatus.PENDING
+        assert task.id in download_manager.tasks
+
+    def test_create_task_with_custom_filename(self, download_manager):
+        """Test creating task with custom filename"""
+        request = DownloadRequest(
+            url="https://example.com/file.mp4",
+            filename="custom_name.mp4"
+        )
+        task = download_manager.create_task(request)
+        assert task.filename == "custom_name.mp4"
+
+    def test_create_task_without_filename(self, download_manager):
+        """Test creating task without filename uses default"""
+        request = DownloadRequest(url="https://example.com/file.mp4")
+        task = download_manager.create_task(request)
+        assert task.filename == "download"
+
+    def test_create_multiple_tasks(self, download_manager):
+        """Test creating multiple tasks"""
+        request1 = DownloadRequest(url="https://example.com/file1.mp4")
+        request2 = DownloadRequest(url="https://example.com/file2.mp4")
+
+        task1 = download_manager.create_task(request1)
+        task2 = download_manager.create_task(request2)
+
+        assert task1.id != task2.id
+        assert len(download_manager.tasks) == 2
+
+    def test_get_task(self, download_manager, sample_download_request):
+        """Test retrieving a task by ID"""
+        task = download_manager.create_task(sample_download_request)
+        retrieved_task = download_manager.get_task(task.id)
+
+        assert retrieved_task is not None
+        assert retrieved_task.id == task.id
+        assert retrieved_task.url == task.url
+
+    def test_get_task_nonexistent(self, download_manager):
+        """Test retrieving a non-existent task"""
+        task = download_manager.get_task("nonexistent-id")
+        assert task is None
+
+    def test_get_all_tasks(self, download_manager):
+        """Test retrieving all tasks"""
+        # Create multiple tasks
+        for i in range(3):
+            request = DownloadRequest(url=f"https://example.com/file{i}.mp4")
+            download_manager.create_task(request)
+
+        all_tasks = download_manager.get_all_tasks()
+        assert len(all_tasks) == 3
+        assert all(isinstance(task, DownloadTask) for task in all_tasks)
+
+    def test_get_all_tasks_empty(self, download_manager):
+        """Test retrieving all tasks when none exist"""
+        all_tasks = download_manager.get_all_tasks()
+        assert all_tasks == []
+
+
+class TestDownloadManagerStartDownload:
+    """Tests for starting downloads"""
+
+    @pytest.mark.asyncio
+    async def test_start_download_success(self, download_manager, sample_download_request):
+        """Test starting a download successfully"""
+        task = download_manager.create_task(sample_download_request)
+
+        # Mock the actual download process
+        with patch('app.download_manager.get_downloader') as mock_get_downloader:
+            mock_downloader = AsyncMock()
+            mock_downloader.get_download_link.return_value = (
+                "https://example.com/direct_link",
+                "video.mp4"
+            )
+            mock_get_downloader.return_value = mock_downloader
+
+            # Mock httpx client
+            with patch('httpx.AsyncClient') as mock_client_class:
+                mock_client = AsyncMock()
+                mock_response = AsyncMock()
+                mock_response.status_code = 200
+                mock_response.headers = {"content-length": "1000"}
+                mock_response.raise_for_status = Mock()
+
+                # Mock streaming
+                async def mock_aiter_bytes(chunk_size):
+                    yield b"x" * 1000  # Single chunk
+
+                mock_response.aiter_bytes = mock_aiter_bytes
+                mock_client.stream.return_value.__aenter__.return_value = mock_response
+                mock_client_class.return_value = mock_client
+
+                await download_manager.start_download(task.id)
+
+                # Give it a moment to start
+                await asyncio.sleep(0.1)
+
+    @pytest.mark.asyncio
+    async def test_start_download_nonexistent_task(self, download_manager):
+        """Test starting download for non-existent task"""
+        with pytest.raises(ValueError, match="not found"):
+            await download_manager.start_download("nonexistent-id")
+
+    @pytest.mark.asyncio
+    async def test_start_download_already_downloading(self, download_manager, sample_download_request):
+        """Test starting a task that's already downloading"""
+        task = download_manager.create_task(sample_download_request)
+        task.status = DownloadStatus.DOWNLOADING
+
+        # Should not raise an error, just return
+        await download_manager.start_download(task.id)
+
+
+class TestDownloadManagerPauseDownload:
+    """Tests for pausing downloads"""
+
+    @pytest.mark.asyncio
+    async def test_pause_download(self, download_manager):
+        """Test pausing an active download"""
+        request = DownloadRequest(url="https://example.com/file.mp4")
+        task = download_manager.create_task(request)
+        task.status = DownloadStatus.DOWNLOADING
+
+        # Create a fake active download
+        async def fake_download():
+            await asyncio.sleep(10)
+
+        download_manager.active_downloads[task.id] = asyncio.create_task(fake_download())
+
+        await download_manager.pause_download(task.id)
+
+        assert task.status == DownloadStatus.PAUSED
+        assert task.id not in download_manager.active_downloads
+
+    @pytest.mark.asyncio
+    async def test_pause_download_not_downloading(self, download_manager):
+        """Test pausing a task that's not downloading"""
+        request = DownloadRequest(url="https://example.com/file.mp4")
+        task = download_manager.create_task(request)
+        task.status = DownloadStatus.PENDING
+
+        # Should not crash
+        await download_manager.pause_download(task.id)
+        assert task.status == DownloadStatus.PENDING
+
+    @pytest.mark.asyncio
+    async def test_pause_nonexistent_task(self, download_manager):
+        """Test pausing a non-existent task"""
+        # Should not crash
+        await download_manager.pause_download("nonexistent-id")
+
+
+class TestDownloadManagerCancelDownload:
+    """Tests for canceling downloads"""
+
+    @pytest.mark.asyncio
+    async def test_cancel_download(self, download_manager, temp_download_dir):
+        """Test canceling a download"""
+        request = DownloadRequest(url="https://example.com/file.mp4")
+        task = download_manager.create_task(request)
+        task.status = DownloadStatus.DOWNLOADING
+
+        # Create a fake file
+        file_path = temp_download_dir / "test_file.mp4"
+        file_path.write_text("test content")
+        task.file_path = str(file_path)
+
+        await download_manager.cancel_download(task.id)
+
+        assert task.status == DownloadStatus.CANCELLED
+        assert not file_path.exists()
+
+    @pytest.mark.asyncio
+    async def test_cancel_download_with_active_task(self, download_manager):
+        """Test canceling a download with an active task"""
+        request = DownloadRequest(url="https://example.com/file.mp4")
+        task = download_manager.create_task(request)
+        task.status = DownloadStatus.DOWNLOADING
+
+        # Create a fake active download
+        async def fake_download():
+            try:
+                await asyncio.sleep(10)
+            except asyncio.CancelledError:
+                raise
+
+        fake_task = asyncio.create_task(fake_download())
+        download_manager.active_downloads[task.id] = fake_task
+
+        await download_manager.cancel_download(task.id)
+
+        assert task.status == DownloadStatus.CANCELLED
+        assert task.id not in download_manager.active_downloads
+
+    @pytest.mark.asyncio
+    async def test_cancel_nonexistent_task(self, download_manager):
+        """Test canceling a non-existent task"""
+        # Should not crash
+        await download_manager.cancel_download("nonexistent-id")
+
+
+class TestDownloadManagerConcurrency:
+    """Tests for concurrent download management"""
+
+    def test_semaphore_limit(self, download_manager):
+        """Test that semaphore respects max_parallel limit"""
+        manager = DownloadManager(max_parallel=2)
+        assert manager._semaphore._value == 2
+
+    @pytest.mark.asyncio
+    async def test_parallel_downloads_respect_limit(self, download_manager):
+        """Test that parallel downloads respect the limit"""
+        download_count = 0
+        max_concurrent = 0
+
+        async def mock_download():
+            nonlocal download_count, max_concurrent
+            download_count += 1
+            max_concurrent = max(max_concurrent, download_count)
+            await asyncio.sleep(0.1)
+            download_count -= 1
+
+        # Start more downloads than max_parallel
+        tasks = []
+        for _ in range(5):
+            task = asyncio.create_task(mock_download())
+            tasks.append(task)
+
+        await asyncio.gather(*tasks)
+
+        # With proper semaphore, should not exceed max_parallel
+        # Note: This is a basic test, real concurrency testing needs more setup
+
+
+class TestDownloadManagerProgressTracking:
+    """Tests for progress tracking during downloads"""
+
+    def test_task_progress_initialization(self, download_manager):
+        """Test that task initializes with correct progress values"""
+        request = DownloadRequest(url="https://example.com/file.mp4")
+        task = download_manager.create_task(request)
+
+        assert task.progress == 0.0
+        assert task.downloaded_bytes == 0
+        assert task.speed == 0.0
+        assert task.total_bytes is None
+
+    def test_task_timestamps(self, download_manager):
+        """Test that task timestamps are set correctly"""
+        request = DownloadRequest(url="https://example.com/file.mp4")
+        task = download_manager.create_task(request)
+
+        assert task.created_at is not None
+        assert isinstance(task.created_at, datetime)
+        assert task.started_at is None
+        assert task.completed_at is None
+
+
+class TestDownloadManagerFileHandling:
+    """Tests for file handling during downloads"""
+
+    def test_file_path_assignment(self, download_manager, temp_download_dir):
+        """Test that file paths are assigned correctly"""
+        request = DownloadRequest(
+            url="https://example.com/video.mp4",
+            filename="test_video.mp4"
+        )
+        task = download_manager.create_task(request)
+
+        expected_path = str(temp_download_dir / "test_video.mp4")
+        # File path is set during download, not creation
+        assert task.file_path is None or task.file_path == expected_path
+
+    def test_download_dir_persistence(self, download_manager):
+        """Test that download directory persists across operations"""
+        assert download_manager.download_dir.exists()
+        assert download_manager.download_dir.is_dir()
+
+
+class TestDownloadManagerErrorHandling:
+    """Tests for error handling"""
+
+    @pytest.mark.asyncio
+    async def test_download_error_sets_failed_status(self):
+        """Test that download errors set task to failed status"""
+        temp_dir = Path(__file__).parent / "temp_test_downloads"
+        temp_dir.mkdir(exist_ok=True)
+
+        try:
+            manager = DownloadManager(download_dir=str(temp_dir))
+            request = DownloadRequest(url="https://invalid-url-that-will-fail.com/file.mp4")
+            task = manager.create_task(request)
+
+            # Mock get_downloader to raise an error
+            with patch('app.download_manager.get_downloader') as mock_get_downloader:
+                mock_downloader = AsyncMock()
+                mock_downloader.get_download_link.side_effect = Exception("Download failed")
+                mock_get_downloader.return_value = mock_downloader
+
+                try:
+                    await manager.start_download(task.id)
+                    await asyncio.sleep(0.1)  # Give it time to process
+                except:
+                    pass
+
+                # The task should be in tasks dict
+                if task.id in manager.tasks:
+                    assert manager.tasks[task.id].status == DownloadStatus.FAILED
+                    assert manager.tasks[task.id].error is not None
+        finally:
+            # Cleanup
+            import shutil
+            shutil.rmtree(temp_dir, ignore_errors=True)
+
+
+class TestDownloadManagerEdgeCases:
+    """Tests for edge cases and boundary conditions"""
+
+    def test_create_task_with_empty_url(self, download_manager):
+        """Test creating task with empty URL"""
+        with pytest.raises(Exception):  # Pydantic validation error
+            request = DownloadRequest(url="")
+            download_manager.create_task(request)
+
+    def test_create_task_with_special_chars_in_filename(self, download_manager):
+        """Test creating task with special characters in filename"""
+        request = DownloadRequest(
+            url="https://example.com/file.mp4",
+            filename="test file [2023] - épisode 1.mp4"
+        )
+        task = download_manager.create_task(request)
+        assert "[" in task.filename
+        assert "]" in task.filename
+
+    def test_concurrent_task_creation(self, download_manager):
+        """Test creating tasks concurrently"""
+        async def create_tasks():
+            tasks = []
+            for i in range(10):
+                request = DownloadRequest(url=f"https://example.com/file{i}.mp4")
+                task = download_manager.create_task(request)
+                tasks.append(task)
+            return tasks
+
+        tasks = asyncio.run(create_tasks())
+        assert len(tasks) == 10
+        assert len(download_manager.tasks) == 10
diff --git a/tests/test_downloaders.py b/tests/test_downloaders.py
new file mode 100644
index 0000000..d286304
--- /dev/null
+++ b/tests/test_downloaders.py
@@ -0,0 +1,339 @@
+"""
+Unit tests for downloaders
+"""
+import pytest
+from unittest.mock import Mock, AsyncMock, patch, MagicMock
+from bs4 import BeautifulSoup
+
+from app.downloaders.base import BaseDownloader
+
+
+class TestBaseDownloader:
+    """Tests for BaseDownloader abstract class"""
+
+    def test_base_downloader_is_abstract(self):
+        """Test that BaseDownloader cannot be instantiated directly"""
+        with pytest.raises(TypeError):
+            BaseDownloader()
+
+    def test_base_downloader_can_handle_not_implemented(self):
+        """Test that can_handle raises NotImplementedError"""
+        class TestDownloader(BaseDownloader):
+            async def get_download_link(self, url: str):
+                return ("http://example.com/download", "file.mp4")
+
+        downloader = TestDownloader()
+        with pytest.raises(NotImplementedError):
+            downloader.can_handle("https://example.com")
+
+    def test_base_downloader_get_download_link_not_implemented(self):
+        """Test that get_download_link raises NotImplementedError"""
+        class TestDownloader(BaseDownloader):
+            def can_handle(self, url: str) -> bool:
+                return True
+
+        downloader = TestDownloader()
+        with pytest.raises(NotImplementedError):
+            # Need to await the coroutine
+            import asyncio
+            asyncio.run(downloader.get_download_link("https://example.com"))
+
+    @pytest.mark.asyncio
+    async def test_base_downloader_fetch_page(self):
+        """Test _fetch_page method"""
+        class TestDownloader(BaseDownloader):
+            def can_handle(self, url: str) -> bool:
+                return True
+
+            async def get_download_link(self, url: str):
+                return ("http://example.com/download", "file.mp4")
+
+        downloader = TestDownloader()
+        # Mock the client.get method
+        with patch.object(downloader.client, 'get') as mock_get:
+            mock_response = Mock()
+            mock_response.text = "<html>Test content</html>"
+            mock_response.raise_for_status = Mock()
+            mock_get.return_value = mock_response
+
+            content = await downloader._fetch_page("https://example.com")
+            assert content == "<html>Test content</html>"
+            mock_get.assert_called_once_with("https://example.com")
+
+    @pytest.mark.asyncio
+    async def test_base_downloader_fetch_page_error(self):
+        """Test _fetch_page method with HTTP error"""
+        class TestDownloader(BaseDownloader):
+            def can_handle(self, url: str) -> bool:
+                return True
+
+            async def get_download_link(self, url: str):
+                return ("http://example.com/download", "file.mp4")
+
+        downloader = TestDownloader()
+        with patch.object(downloader.client, 'get') as mock_get:
+            mock_response = Mock()
+            mock_response.raise_for_status.side_effect = Exception("HTTP Error")
+            mock_get.return_value = mock_response
+
+            with pytest.raises(Exception):
+                await downloader._fetch_page("https://example.com")
+
+    def test_extract_filename_from_headers(self):
+        """Test _extract_filename_from_headers method"""
+        class TestDownloader(BaseDownloader):
+            def can_handle(self, url: str) -> bool:
+                return True
+
+            async def get_download_link(self, url: str):
+                return ("http://example.com/download", "file.mp4")
+
+        downloader = TestDownloader()
+
+        # Test with filename in headers
+        headers = {"content-disposition": 'attachment; filename="test.mp4"'}
+        filename = downloader._extract_filename_from_headers(headers)
+        assert filename == "test.mp4"
+
+        # Test without filename
+        headers = {}
+        filename = downloader._extract_filename_from_headers(headers)
+        assert filename is None
+
+        # Test with filename in single quotes
+        headers = {"content-disposition": "attachment; filename='test.mp4'"}
+        filename = downloader._extract_filename_from_headers(headers)
+        assert filename == "'test.mp4'"
+
+    @pytest.mark.asyncio
+    async def test_search_anime_default(self):
+        """Test default search_anime returns empty list"""
+        class TestDownloader(BaseDownloader):
+            def can_handle(self, url: str) -> bool:
+                return True
+
+            async def get_download_link(self, url: str):
+                return ("http://example.com/download", "file.mp4")
+
+        downloader = TestDownloader()
+        results = await downloader.search_anime("naruto", "vostfr")
+        assert results == []
+
+    @pytest.mark.asyncio
+    async def test_get_episodes_default(self):
+        """Test default get_episodes returns empty list"""
+        class TestDownloader(BaseDownloader):
+            def can_handle(self, url: str) -> bool:
+                return True
+
+            async def get_download_link(self, url: str):
+                return ("http://example.com/download", "file.mp4")
+
+        downloader = TestDownloader()
+        episodes = await downloader.get_episodes("https://example.com/anime", "vostfr")
+        assert episodes == []
+
+    @pytest.mark.asyncio
+    async def test_close(self):
+        """Test close method"""
+        class TestDownloader(BaseDownloader):
+            def can_handle(self, url: str) -> bool:
+                return True
+
+            async def get_download_link(self, url: str):
+                return ("http://example.com/download", "file.mp4")
+
+        downloader = TestDownloader()
+        # Mock the client.aclose method
+        with patch.object(downloader.client, 'aclose') as mock_aclose:
+            mock_aclose.return_value = AsyncMock()
+            await downloader.close()
+            mock_aclose.assert_called_once()
+
+
+# Test for concrete downloader implementations
+class TestDownloaderRegistration:
+    """Tests for downloader registration system"""
+
+    def test_get_downloader_returns_downloader(self):
+        """Test that get_downloader returns appropriate downloader"""
+        from app.downloaders import get_downloader
+
+        # Test with 1fichier URL
+        downloader = get_downloader("https://1fichier.com/?abcdef")
+        assert downloader is not None
+        assert downloader.can_handle("https://1fichier.com/?abcdef")
+
+        # Test with doodstream URL
+        downloader = get_downloader("https://doodstream.com/d/abcdef")
+        assert downloader is not None
+        assert downloader.can_handle("https://doodstream.com/d/abcdef")
+
+    def test_get_downloader_fallback(self):
+        """Test that get_downloader falls back to other for unknown hosts"""
+        from app.downloaders import get_downloader
+
+        downloader = get_downloader("https://unknown-host.com/file")
+        assert downloader is not None
+
+    def test_all_downloaders_have_required_methods(self):
+        """Test that all registered downloaders implement required methods"""
+        from app.downloaders import get_downloader
+
+        test_urls = [
+            "https://1fichier.com/?test",
+            "https://doodstream.com/d/test",
+            "https://rapidfile.net/test",
+            "https://uptobox.com/test"
+        ]
+
+        for url in test_urls:
+            downloader = get_downloader(url)
+            assert hasattr(downloader, 'can_handle')
+            assert hasattr(downloader, 'get_download_link')
+            assert callable(downloader.can_handle)
+            # get_download_link is async, so we can't test with callable()
+            import inspect
+            assert inspect.iscoroutinefunction(downloader.get_download_link)
+
+
+class TestDownloaderCanHandle:
+    """Tests for can_handle method in concrete downloaders"""
+
+    def test_unfichier_can_handle(self):
+        """Test UnfichierDownloader.can_handle"""
+        from app.downloaders.unfichier import UnfichierDownloader
+
+        downloader = UnfichierDownloader()
+        assert downloader.can_handle("https://1fichier.com/?abc123") is True
+        assert downloader.can_handle("https://1fichier.fr/?abc123") is True
+        assert downloader.can_handle("http://1fichier.com/?abc123") is True
+        assert downloader.can_handle("https://doodstream.com/test") is False
+        assert downloader.can_handle("https://example.com/test") is False
+
+    def test_doodstream_can_handle(self):
+        """Test DoodstreamDownloader.can_handle"""
+        from app.downloaders.doodstream import DoodstreamDownloader
+
+        downloader = DoodstreamDownloader()
+        assert downloader.can_handle("https://doodstream.com/d/abc123") is True
+        assert downloader.can_handle("https://dood.to/d/abc123") is True
+        assert downloader.can_handle("https://dood.lol/d/abc123") is True
+        assert downloader.can_handle("https://1fichier.com/?test") is False
+
+    def test_rapidfile_can_handle(self):
+        """Test RapidfileDownloader.can_handle"""
+        from app.downloaders.rapidfile import RapidfileDownloader
+
+        downloader = RapidfileDownloader()
+        assert downloader.can_handle("https://rapidfile.net/abc123") is True
+        assert downloader.can_handle("https://rapidfile.com/abc123") is True
+        assert downloader.can_handle("https://doodstream.com/test") is False
+
+    def test_uptobox_can_handle(self):
+        """Test UptoboxDownloader.can_handle"""
+        from app.downloaders.uptobox import UptoboxDownloader
+
+        downloader = UptoboxDownloader()
+        assert downloader.can_handle("https://uptobox.com/abc123") is True
+        assert downloader.can_handle("https://uptobox.fr/abc123") is True
+        assert downloader.can_handle("https://doodstream.com/test") is False
+
+    def test_vidmoly_can_handle(self):
+        """Test VidMolyDownloader.can_handle"""
+        from app.downloaders.vidmoly import VidMolyDownloader
+
+        downloader = VidMolyDownloader()
+        assert downloader.can_handle("https://vidmoly.to/abc123") is True
+        assert downloader.can_handle("https://vidmoly.com/abc123") is True
+        assert downloader.can_handle("https://doodstream.com/test") is False
+
+    def test_sendvid_can_handle(self):
+        """Test SendVidDownloader.can_handle"""
+        from app.downloaders.sendvid import SendVidDownloader
+
+        downloader = SendVidDownloader()
+        assert downloader.can_handle("https://sendvid.com/abc123") is True
+        assert downloader.can_handle("https://doodstream.com/test") is False
+
+
+class TestAnimeDownloaders:
+    """Tests for anime provider downloaders"""
+
+    @pytest.mark.asyncio
+    async def test_anime_sama_search(self):
+        """Test AnimeSamaDownloader.search_anime"""
+        from app.downloaders.animesama import AnimeSamaDownloader
+
+        downloader = AnimeSamaDownloader()
+        with patch.object(downloader, '_fetch_page') as mock_fetch:
+            # Mock HTML response
+            mock_html = """
+            <html>
+                <div class="sa-popflex">
+                    <a href="/anime/test-anime/" class="sa-poster">
+                        <img src="https://example.com/poster.jpg" alt="Test Anime">
+                        <div class="sa-poster-info">
+                            <h2 class="entry-title">Test Anime</h2>
+                        </div>
+                    </a>
+                </div>
+            </html>
+            """
+            mock_fetch.return_value = mock_html
+
+            results = await downloader.search_anime("test anime", "vostfr")
+            # Should return results based on the mocked HTML
+            assert isinstance(results, list)
+
+    @pytest.mark.asyncio
+    async def test_neko_sama_can_handle(self):
+        """Test NekoSamaDownloader.can_handle"""
+        from app.downloaders.nekosama import NekoSamaDownloader
+
+        downloader = NekoSamaDownloader()
+        assert downloader.can_handle("https://neko-sama.franime/test") is True
+        assert downloader.can_handle("https://neko-sama.netanime/test") is True
+        assert downloader.can_handle("https://anime-sama.si/test") is False
+
+    @pytest.mark.asyncio
+    async def test_anime_ultime_can_handle(self):
+        """Test AnimeUltimeDownloader.can_handle"""
+        from app.downloaders.animeultime import AnimeUltimeDownloader
+
+        downloader = AnimeUltimeDownloader()
+        assert downloader.can_handle("https://anime-ultime.net/test") is True
+        assert downloader.can_handle("https://anime-sama.si/test") is False
+
+    @pytest.mark.asyncio
+    async def test_vostfree_can_handle(self):
+        """Test VostfreeDownloader.can_handle"""
+        from app.downloaders.vostfree import VostfreeDownloader
+
+        downloader = VostfreeDownloader()
+        assert downloader.can_handle("https://vostfree.top/test") is True
+        assert downloader.can_handle("https://anime-sama.si/test") is False
+
+
+class TestDownloaderUrlExtraction:
+    """Tests for URL extraction methods"""
+
+    @pytest.mark.asyncio
+    async def test_get_download_link_mock(self):
+        """Test get_download_link with mocked response"""
+        from app.downloaders.unfichier import UnfichierDownloader
+
+        downloader = UnfichierDownloader()
+        with patch.object(downloader, '_fetch_page') as mock_fetch:
+            # Mock a simple HTML page
+            mock_fetch.return_value = "<html><body>Test page</body></html>"
+
+            # This should not crash
+            try:
+                download_url, filename = await downloader.get_download_link("https://1fichier.com/?test")
+                # Result may vary based on actual implementation
+                assert isinstance(download_url, str)
+                assert isinstance(filename, str)
+            except Exception as e:
+                # Some downloaders might fail with mock HTML
+                assert isinstance(e, (ValueError, AttributeError, KeyError))
diff --git a/tests/test_favorites.py b/tests/test_favorites.py
new file mode 100644
index 0000000..5389d3e
--- /dev/null
+++ b/tests/test_favorites.py
@@ -0,0 +1,553 @@
+"""
+Unit tests for FavoritesManager
+"""
+import pytest
+import json
+from pathlib import Path
+from unittest.mock import patch, AsyncMock, mock_open
+
+from app.favorites import FavoritesManager, get_favorites_manager
+
+
+class TestFavoritesManagerInit:
+    """Tests for FavoritesManager initialization"""
+
+    def test_init_default_path(self, temp_dir):
+        """Test FavoritesManager initialization with default path"""
+        manager = FavoritesManager(storage_path=str(temp_dir / "favorites.json"))
+        assert manager.storage_path == temp_dir / "favorites.json"
+        assert manager._favorites == {}
+
+    def test_init_creates_directory(self, temp_dir):
+        """Test that initialization creates the parent directory"""
+        storage_path = temp_dir / "subdir" / "favorites.json"
+        assert not storage_path.parent.exists()
+
+        manager = FavoritesManager(storage_path=str(storage_path))
+        assert storage_path.parent.exists()
+        assert storage_path.parent.is_dir()
+
+    def test_global_manager_singleton(self):
+        """Test that get_favorites_manager returns singleton"""
+        manager1 = get_favorites_manager()
+        manager2 = get_favorites_manager()
+        assert manager1 is manager2
+
+
+class TestFavoritesManagerLoad:
+    """Tests for loading favorites from disk"""
+
+    @pytest.mark.asyncio
+    async def test_load_empty_file(self, favorites_manager):
+        """Test loading from empty file"""
+        await favorites_manager._load()
+        assert favorites_manager._favorites == {}
+
+    @pytest.mark.asyncio
+    async def test_load_with_data(self, temp_dir):
+        """Test loading favorites with data"""
+        storage_path = temp_dir / "test_favorites.json"
+        test_data = {
+            "anime-1": {
+                "id": "anime-1",
+                "title": "Test Anime 1",
+                "url": "https://example.com/anime1",
+                "provider": "anime-sama"
+            }
+        }
+        storage_path.write_text(json.dumps(test_data))
+
+        manager = FavoritesManager(storage_path=str(storage_path))
+        await manager._load()
+
+        assert len(manager._favorites) == 1
+        assert "anime-1" in manager._favorites
+        assert manager._favorites["anime-1"]["title"] == "Test Anime 1"
+
+    @pytest.mark.asyncio
+    async def test_load_invalid_json(self, temp_dir):
+        """Test loading invalid JSON"""
+        storage_path = temp_dir / "invalid.json"
+        storage_path.write_text("invalid json content {")
+
+        manager = FavoritesManager(storage_path=str(storage_path))
+        await manager._load()
+
+        # Should default to empty dict on error
+        assert manager._favorites == {}
+
+    @pytest.mark.asyncio
+    async def test_load_nonexistent_file(self, temp_dir):
+        """Test loading when file doesn't exist"""
+        storage_path = temp_dir / "nonexistent.json"
+        assert not storage_path.exists()
+
+        manager = FavoritesManager(storage_path=str(storage_path))
+        await manager._load()
+
+        assert manager._favorites == {}
+
+
+class TestFavoritesManagerSave:
+    """Tests for saving favorites to disk"""
+
+    @pytest.mark.asyncio
+    async def test_save_favorites(self, temp_dir):
+        """Test saving favorites to disk"""
+        storage_path = temp_dir / "test_save.json"
+        manager = FavoritesManager(storage_path=str(storage_path))
+        manager._favorites = {
+            "anime-1": {"id": "anime-1", "title": "Test Anime"}
+        }
+
+        await manager._save()
+
+        assert storage_path.exists()
+        content = storage_path.read_text()
+        saved_data = json.loads(content)
+        assert saved_data == {"anime-1": {"id": "anime-1", "title": "Test Anime"}}
+
+
+class TestFavoritesManagerAdd:
+    """Tests for adding favorites"""
+
+    @pytest.mark.asyncio
+    async def test_add_favorite_new(self, favorites_manager):
+        """Test adding a new favorite"""
+        result = await favorites_manager.add_favorite(
+            anime_id="anime-123",
+            title="Test Anime",
+            url="https://example.com/anime",
+            provider="anime-sama",
+            metadata={"genres": ["Action"]},
+            poster_url="https://example.com/poster.jpg"
+        )
+
+        assert result["id"] == "anime-123"
+        assert result["title"] == "Test Anime"
+        assert result["url"] == "https://example.com/anime"
+        assert result["provider"] == "anime-sama"
+        assert result["metadata"]["genres"] == ["Action"]
+        assert result["poster_url"] == "https://example.com/poster.jpg"
+        assert "created_at" in result
+        assert "updated_at" in result
+
+        # Verify it was saved
+        await favorites_manager._load()
+        assert "anime-123" in favorites_manager._favorites
+
+    @pytest.mark.asyncio
+    async def test_add_favorite_minimal(self, favorites_manager):
+        """Test adding favorite with minimal data"""
+        result = await favorites_manager.add_favorite(
+            anime_id="anime-456",
+            title="Minimal Anime",
+            url="https://example.com/minimal",
+            provider="neko-sama"
+        )
+
+        assert result["id"] == "anime-456"
+        assert result["metadata"] == {}
+        assert result["poster_url"] is None
+
+    @pytest.mark.asyncio
+    async def test_add_favorite_update_existing(self, favorites_manager):
+        """Test updating an existing favorite"""
+        # Add initial favorite
+        await favorites_manager.add_favorite(
+            anime_id="anime-789",
+            title="Original Title",
+            url="https://example.com/anime",
+            provider="anime-sama",
+            metadata={"rating": "7.0/10"}
+        )
+
+        # Update with new metadata
+        result = await favorites_manager.add_favorite(
+            anime_id="anime-789",
+            title="Updated Title",  # This won't update
+            url="https://example.com/anime",
+            provider="anime-sama",
+            metadata={"rating": "8.5/10"},
+            poster_url="https://example.com/new_poster.jpg"
+        )
+
+        # Title should remain the same, metadata and poster should update
+        assert result["title"] == "Original Title"
+        assert result["metadata"]["rating"] == "8.5/10"
+        assert result["poster_url"] == "https://example.com/new_poster.jpg"
+
+    @pytest.mark.asyncio
+    async def test_add_favorite_preserves_created_at(self, favorites_manager):
+        """Test that created_at is preserved on update"""
+        await favorites_manager.add_favorite(
+            anime_id="anime-time",
+            title="Time Test",
+            url="https://example.com",
+            provider="anime-sama"
+        )
+
+        import time
+        await asyncio.sleep(0.1)  # Small delay
+
+        result = await favorites_manager.add_favorite(
+            anime_id="anime-time",
+            title="Time Test",
+            url="https://example.com",
+            provider="anime-sama",
+            metadata={"new": "data"}
+        )
+
+        # updated_at should be newer than created_at
+        from datetime import datetime
+        created = datetime.fromisoformat(result["created_at"])
+        updated = datetime.fromisoformat(result["updated_at"])
+        assert updated > created
+
+
+class TestFavoritesManagerRemove:
+    """Tests for removing favorites"""
+
+    @pytest.mark.asyncio
+    async def test_remove_favorite_success(self, favorites_manager):
+        """Test successfully removing a favorite"""
+        # Add favorite first
+        await favorites_manager.add_favorite(
+            anime_id="anime-remove",
+            title="Remove Me",
+            url="https://example.com",
+            provider="anime-sama"
+        )
+
+        # Remove it
+        result = await favorites_manager.remove_favorite("anime-remove")
+        assert result is True
+
+        # Verify it's gone
+        await favorites_manager._load()
+        assert "anime-remove" not in favorites_manager._favorites
+
+    @pytest.mark.asyncio
+    async def test_remove_favorite_nonexistent(self, favorites_manager):
+        """Test removing a non-existent favorite"""
+        result = await favorites_manager.remove_favorite("nonexistent-id")
+        assert result is False
+
+    @pytest.mark.asyncio
+    async def test_remove_multiple_favorites(self, favorites_manager):
+        """Test removing multiple favorites"""
+        # Add multiple favorites
+        for i in range(5):
+            await favorites_manager.add_favorite(
+                anime_id=f"anime-{i}",
+                title=f"Anime {i}",
+                url=f"https://example.com/anime{i}",
+                provider="anime-sama"
+            )
+
+        # Remove some
+        await favorites_manager.remove_favorite("anime-1")
+        await favorites_manager.remove_favorite("anime-3")
+
+        await favorites_manager._load()
+        assert len(favorites_manager._favorites) == 3
+        assert "anime-1" not in favorites_manager._favorites
+        assert "anime-3" not in favorites_manager._favorites
+
+
+class TestFavoritesManagerGet:
+    """Tests for getting favorites"""
+
+    @pytest.mark.asyncio
+    async def test_get_favorite_success(self, favorites_manager):
+        """Test getting an existing favorite"""
+        await favorites_manager.add_favorite(
+            anime_id="anime-get",
+            title="Get Test",
+            url="https://example.com",
+            provider="anime-sama"
+        )
+
+        result = await favorites_manager.get_favorite("anime-get")
+        assert result is not None
+        assert result["id"] == "anime-get"
+        assert result["title"] == "Get Test"
+
+    @pytest.mark.asyncio
+    async def test_get_favorite_nonexistent(self, favorites_manager):
+        """Test getting a non-existent favorite"""
+        result = await favorites_manager.get_favorite("nonexistent-id")
+        assert result is None
+
+
+class TestFavoritesManagerList:
+    """Tests for listing favorites"""
+
+    @pytest.mark.asyncio
+    async def test_list_favorites_empty(self, favorites_manager):
+        """Test listing when no favorites exist"""
+        result = await favorites_manager.list_favorites()
+        assert result == []
+
+    @pytest.mark.asyncio
+    async def test_list_favorites_default_sort(self, favorites_manager):
+        """Test listing favorites with default sorting"""
+        # Add favorites with different timestamps
+        import time
+        for i in range(3):
+            await favorites_manager.add_favorite(
+                anime_id=f"anime-list-{i}",
+                title=f"Anime {i}",
+                url=f"https://example.com/{i}",
+                provider="anime-sama"
+            )
+            await asyncio.sleep(0.05)  # Small delay for different timestamps
+
+        result = await favorites_manager.list_favorites()
+        assert len(result) == 3
+        # Default is sort by created_at desc, so last added should be first
+        assert result[0]["id"] == "anime-list-2"
+
+    @pytest.mark.asyncio
+    async def test_list_favorites_sort_by_title(self, favorites_manager):
+        """Test sorting by title"""
+        await favorites_manager.add_favorite("z-anime", "Z Anime", "https://example.com/z", "anime-sama")
+        await asyncio.sleep(0.05)
+        await favorites_manager.add_favorite("a-anime", "A Anime", "https://example.com/a", "anime-sama")
+
+        result_asc = await favorites_manager.list_favorites(sort_by="title", order="asc")
+        assert result_asc[0]["title"] == "A Anime"
+
+        result_desc = await favorites_manager.list_favorites(sort_by="title", order="desc")
+        assert result_desc[0]["title"] == "Z Anime"
+
+    @pytest.mark.asyncio
+    async def test_list_favorites_filter_by_provider(self, favorites_manager):
+        """Test filtering by provider"""
+        await favorites_manager.add_favorite("anime-1", "Anime 1", "https://example.com/1", "anime-sama")
+        await favorites_manager.add_favorite("anime-2", "Anime 2", "https://example.com/2", "neko-sama")
+
+        result = await favorites_manager.list_favorites(filter_provider="anime-sama")
+        assert len(result) == 1
+        assert result[0]["provider"] == "anime-sama"
+
+    @pytest.mark.asyncio
+    async def test_list_favorites_filter_by_genre(self, favorites_manager):
+        """Test filtering by genre"""
+        await favorites_manager.add_favorite(
+            "anime-action",
+            "Action Anime",
+            "https://example.com/action",
+            "anime-sama",
+            metadata={"genres": ["Action", "Adventure"]}
+        )
+        await favorites_manager.add_favorite(
+            "anime-drama",
+            "Drama Anime",
+            "https://example.com/drama",
+            "anime-sama",
+            metadata={"genres": ["Drama", "Romance"]}
+        )
+
+        result = await favorites_manager.list_favorites(filter_genre="Action")
+        assert len(result) == 1
+        assert result[0]["id"] == "anime-action"
+
+    @pytest.mark.asyncio
+    async def test_list_favorites_combined_filters(self, favorites_manager):
+        """Test combining filters"""
+        await favorites_manager.add_favorite(
+            "anime-1",
+            "Anime 1",
+            "https://example.com/1",
+            "anime-sama",
+            metadata={"genres": ["Action"]}
+        )
+        await favorites_manager.add_favorite(
+            "anime-2",
+            "Anime 2",
+            "https://example.com/2",
+            "neko-sama",
+            metadata={"genres": ["Action"]}
+        )
+
+        result = await favorites_manager.list_favorites(
+            filter_provider="anime-sama",
+            filter_genre="Action"
+        )
+        assert len(result) == 1
+        assert result[0]["id"] == "anime-1"
+
+
+class TestFavoritesManagerIsFavorite:
+    """Tests for is_favorite method"""
+
+    @pytest.mark.asyncio
+    async def test_is_favorite_true(self, favorites_manager):
+        """Test checking if anime is a favorite (true)"""
+        await favorites_manager.add_favorite(
+            "anime-check",
+            "Check Anime",
+            "https://example.com",
+            "anime-sama"
+        )
+
+        result = await favorites_manager.is_favorite("anime-check")
+        assert result is True
+
+    @pytest.mark.asyncio
+    async def test_is_favorite_false(self, favorites_manager):
+        """Test checking if anime is a favorite (false)"""
+        result = await favorites_manager.is_favorite("nonexistent-id")
+        assert result is False
+
+
+class TestFavoritesManagerToggle:
+    """Tests for toggle_favorite method"""
+
+    @pytest.mark.asyncio
+    async def test_toggle_favorite_add(self, favorites_manager):
+        """Test toggling to add a favorite"""
+        result = await favorites_manager.toggle_favorite(
+            anime_id="anime-toggle-add",
+            title="Toggle Add",
+            url="https://example.com",
+            provider="anime-sama"
+        )
+
+        assert result["action"] == "added"
+        assert result["anime_id"] == "anime-toggle-add"
+        assert "favorite" in result
+
+        # Verify it was added
+        is_fav = await favorites_manager.is_favorite("anime-toggle-add")
+        assert is_fav is True
+
+    @pytest.mark.asyncio
+    async def test_toggle_favorite_remove(self, favorites_manager):
+        """Test toggling to remove a favorite"""
+        # Add first
+        await favorites_manager.add_favorite(
+            "anime-toggle-remove",
+            title="Toggle Remove",
+            url="https://example.com",
+            provider="anime-sama"
+        )
+
+        # Toggle to remove
+        result = await favorites_manager.toggle_favorite(
+            anime_id="anime-toggle-remove",
+            title="Toggle Remove",
+            url="https://example.com",
+            provider="anime-sama"
+        )
+
+        assert result["action"] == "removed"
+        assert result["anime_id"] == "anime-toggle-remove"
+
+        # Verify it was removed
+        is_fav = await favorites_manager.is_favorite("anime-toggle-remove")
+        assert is_fav is False
+
+
+class TestFavoritesManagerStats:
+    """Tests for get_stats method"""
+
+    @pytest.mark.asyncio
+    async def test_get_stats_empty(self, favorites_manager):
+        """Test getting stats with no favorites"""
+        stats = await favorites_manager.get_stats()
+        assert stats["total"] == 0
+        assert stats["by_provider"] == {}
+        assert stats["by_genre"] == {}
+
+    @pytest.mark.asyncio
+    async def test_get_stats_with_data(self, favorites_manager):
+        """Test getting stats with favorites"""
+        # Add favorites with different providers and genres
+        await favorites_manager.add_favorite(
+            "anime-1",
+            "Anime 1",
+            "https://example.com/1",
+            "anime-sama",
+            metadata={"genres": ["Action", "Adventure"]}
+        )
+        await favorites_manager.add_favorite(
+            "anime-2",
+            "Anime 2",
+            "https://example.com/2",
+            "anime-sama",
+            metadata={"genres": ["Action"]}
+        )
+        await favorites_manager.add_favorite(
+            "anime-3",
+            "Anime 3",
+            "https://example.com/3",
+            "neko-sama",
+            metadata={"genres": ["Drama"]}
+        )
+
+        stats = await favorites_manager.get_stats()
+        assert stats["total"] == 3
+        assert stats["by_provider"]["anime-sama"] == 2
+        assert stats["by_provider"]["neko-sama"] == 1
+        assert stats["by_genre"]["Action"] == 2
+        assert stats["by_genre"]["Adventure"] == 1
+        assert stats["by_genre"]["Drama"] == 1
+
+    @pytest.mark.asyncio
+    async def test_get_stats_multiple_genres(self, favorites_manager):
+        """Test stats with anime having multiple genres"""
+        await favorites_manager.add_favorite(
+            "anime-multi",
+            "Multi Genre Anime",
+            "https://example.com",
+            "anime-sama",
+            metadata={"genres": ["Action", "Adventure", "Fantasy", "Comedy"]}
+        )
+
+        stats = await favorites_manager.get_stats()
+        assert stats["by_genre"]["Action"] == 1
+        assert stats["by_genre"]["Adventure"] == 1
+        assert stats["by_genre"]["Fantasy"] == 1
+        assert stats["by_genre"]["Comedy"] == 1
+
+
+class TestFavoritesManagerConcurrency:
+    """Tests for concurrent operations"""
+
+    @pytest.mark.asyncio
+    async def test_concurrent_add(self, favorites_manager):
+        """Test adding favorites concurrently"""
+        async def add_favorite(i):
+            return await favorites_manager.add_favorite(
+                f"concurrent-{i}",
+                f"Concurrent {i}",
+                f"https://example.com/{i}",
+                "anime-sama"
+            )
+
+        tasks = [add_favorite(i) for i in range(10)]
+        results = await asyncio.gather(*tasks)
+
+        assert len(results) == 10
+
+        # Verify all were added
+        await favorites_manager._load()
+        assert len(favorites_manager._favorites) == 10
+
+    @pytest.mark.asyncio
+    async def test_concurrent_read_write(self, favorites_manager):
+        """Test concurrent reads and writes"""
+        await favorites_manager.add_favorite("base", "Base", "https://example.com", "anime-sama")
+
+        async def operations():
+            tasks = []
+            for i in range(5):
+                tasks.append(favorites_manager.add_favorite(f"rw-{i}", f"RW {i}", "https://example.com", "anime-sama"))
+                tasks.append(favorites_manager.list_favorites())
+            results = await asyncio.gather(*tasks)
+            return results
+
+        results = await operations()
+        assert len(results) == 10
diff --git a/tests/test_models.py b/tests/test_models.py
new file mode 100644
index 0000000..612b6a4
--- /dev/null
+++ b/tests/test_models.py
@@ -0,0 +1,312 @@
+"""
+Unit tests for Pydantic models
+"""
+import pytest
+from datetime import datetime
+from pydantic import ValidationError
+
+from app.models import (
+    DownloadTask,
+    DownloadStatus,
+    DownloadRequest,
+    HostType,
+    AnimeMetadata,
+    AnimeSearchResult
+)
+
+
+class TestDownloadStatus:
+    """Tests for DownloadStatus enum"""
+
+    def test_status_values(self):
+        """Test that all status values are correct"""
+        assert DownloadStatus.PENDING == "pending"
+        assert DownloadStatus.DOWNLOADING == "downloading"
+        assert DownloadStatus.PAUSED == "paused"
+        assert DownloadStatus.COMPLETED == "completed"
+        assert DownloadStatus.FAILED == "failed"
+        assert DownloadStatus.CANCELLED == "cancelled"
+
+    def test_status_comparison(self):
+        """Test status comparison"""
+        status1 = DownloadStatus.PENDING
+        status2 = DownloadStatus.DOWNLOADING
+        assert status1 != status2
+        assert status1 == "pending"
+
+
+class TestHostType:
+    """Tests for HostType enum"""
+
+    def test_host_values(self):
+        """Test that all host type values are correct"""
+        assert HostType.RAPIDFILE == "rapidfile"
+        assert HostType.UNFICHIER == "1fichier"
+        assert HostType.DOODSTREAM == "doodstream"
+        assert HostType.OTHER == "other"
+
+
+class TestDownloadTask:
+    """Tests for DownloadTask model"""
+
+    def test_create_download_task_valid(self, sample_download_task):
+        """Test creating a valid download task"""
+        task = sample_download_task
+        assert task.id == "test-task-123"
+        assert task.url == "https://example.com/file.mp4"
+        assert task.filename == "test_video.mp4"
+        assert task.host == HostType.OTHER
+        assert task.status == DownloadStatus.PENDING
+        assert task.progress == 0.0
+        assert task.downloaded_bytes == 0
+        assert task.total_bytes is None
+        assert task.speed == 0.0
+
+    def test_download_task_with_optional_fields(self):
+        """Test download task with all optional fields"""
+        now = datetime.now()
+        task = DownloadTask(
+            id="task-456",
+            url="https://example.com/file2.mp4",
+            filename="file2.mp4",
+            host=HostType.DOODSTREAM,
+            status=DownloadStatus.DOWNLOADING,
+            progress=50.0,
+            downloaded_bytes=5000000,
+            total_bytes=10000000,
+            speed=1000000.0,
+            error="Test error",
+            created_at=now,
+            started_at=now,
+            completed_at=None,
+            file_path="/downloads/file2.mp4"
+        )
+        assert task.progress == 50.0
+        assert task.downloaded_bytes == 5000000
+        assert task.total_bytes == 10000000
+        assert task.speed == 1000000.0
+        assert task.error == "Test error"
+        assert task.started_at is not None
+        assert task.completed_at is None
+        assert task.file_path == "/downloads/file2.mp4"
+
+    def test_download_task_default_values(self):
+        """Test download task with default values"""
+        task = DownloadTask(
+            id="task-default",
+            url="https://example.com/file.mp4",
+            filename="file.mp4",
+            host=HostType.OTHER,
+            status=DownloadStatus.PENDING,
+            created_at=datetime.now()
+        )
+        assert task.progress == 0.0
+        assert task.downloaded_bytes == 0
+        assert task.speed == 0.0
+        assert task.total_bytes is None
+        assert task.error is None
+        assert task.started_at is None
+        assert task.completed_at is None
+        assert task.file_path is None
+
+    def test_download_task_invalid_url(self):
+        """Test that invalid URL raises ValidationError"""
+        with pytest.raises(ValidationError):
+            DownloadTask(
+                id="task-invalid",
+                url="not-a-valid-url",
+                filename="file.mp4",
+                host=HostType.OTHER,
+                status=DownloadStatus.PENDING,
+                created_at=datetime.now()
+            )
+
+    def test_download_task_negative_progress(self):
+        """Test that negative progress is invalid"""
+        with pytest.raises(ValidationError):
+            DownloadTask(
+                id="task-negative",
+                url="https://example.com/file.mp4",
+                filename="file.mp4",
+                host=HostType.OTHER,
+                status=DownloadStatus.PENDING,
+                progress=-10.0,  # Invalid
+                created_at=datetime.now()
+            )
+
+    def test_download_task_progress_over_100(self):
+        """Test that progress over 100 is invalid"""
+        with pytest.raises(ValidationError):
+            DownloadTask(
+                id="task-over100",
+                url="https://example.com/file.mp4",
+                filename="file.mp4",
+                host=HostType.OTHER,
+                status=DownloadStatus.PENDING,
+                progress=150.0,  # Invalid
+                created_at=datetime.now()
+            )
+
+
+class TestDownloadRequest:
+    """Tests for DownloadRequest model"""
+
+    def test_create_request_with_filename(self, sample_download_request):
+        """Test creating download request with filename"""
+        request = sample_download_request
+        assert request.url == "https://example.com/file.mp4"
+        assert request.filename == "test_video.mp4"
+
+    def test_create_request_without_filename(self):
+        """Test creating download request without filename"""
+        request = DownloadRequest(url="https://example.com/file.mp4")
+        assert request.url == "https://example.com/file.mp4"
+        assert request.filename is None
+
+    def test_request_invalid_url(self):
+        """Test that invalid URL raises ValidationError"""
+        with pytest.raises(ValidationError):
+            DownloadRequest(url="not-a-url")
+
+    def test_request_empty_url(self):
+        """Test that empty URL raises ValidationError"""
+        with pytest.raises(ValidationError):
+            DownloadRequest(url="")
+
+
+class TestAnimeMetadata:
+    """Tests for AnimeMetadata model"""
+
+    def test_create_metadata_all_fields(self):
+        """Test creating metadata with all fields"""
+        metadata = AnimeMetadata(
+            synopsis="Test anime about adventure",
+            genres=["Action", "Adventure", "Fantasy"],
+            rating="8.5/10",
+            release_year=2023,
+            studio="Test Studio",
+            poster_image="https://example.com/poster.jpg",
+            banner_image="https://example.com/banner.jpg",
+            total_episodes=12,
+            status="Completed",
+            alternative_titles=["Test Anime 1", "Test Anime 2"]
+        )
+        assert metadata.synopsis == "Test anime about adventure"
+        assert len(metadata.genres) == 3
+        assert metadata.rating == "8.5/10"
+        assert metadata.release_year == 2023
+        assert metadata.studio == "Test Studio"
+        assert metadata.poster_image is not None
+        assert metadata.banner_image is not None
+        assert metadata.total_episodes == 12
+        assert metadata.status == "Completed"
+        assert len(metadata.alternative_titles) == 2
+
+    def test_create_metadata_minimal(self):
+        """Test creating metadata with minimal fields"""
+        metadata = AnimeMetadata()
+        assert metadata.synopsis is None
+        assert metadata.genres == []
+        assert metadata.rating is None
+        assert metadata.release_year is None
+        assert metadata.studio is None
+        assert metadata.poster_image is None
+        assert metadata.banner_image is None
+        assert metadata.total_episodes is None
+        assert metadata.status is None
+        assert metadata.alternative_titles == []
+
+    def test_metadata_with_some_fields(self):
+        """Test creating metadata with only some fields"""
+        metadata = AnimeMetadata(
+            genres=["Action"],
+            rating="PG-13",
+            release_year=2020
+        )
+        assert len(metadata.genres) == 1
+        assert metadata.genres == ["Action"]
+        assert metadata.rating == "PG-13"
+        assert metadata.release_year == 2020
+        assert metadata.synopsis is None
+        assert metadata.studio is None
+
+    def test_metadata_empty_genres_list(self):
+        """Test metadata with empty genres list"""
+        metadata = AnimeMetadata(genres=[])
+        assert metadata.genres == []
+
+    def test_metadata_negative_year(self):
+        """Test that negative year is handled"""
+        # Pydantic doesn't validate range by default
+        metadata = AnimeMetadata(release_year=-2023)
+        assert metadata.release_year == -2023
+
+    def test_metadata_zero_episodes(self):
+        """Test metadata with zero episodes"""
+        metadata = AnimeMetadata(total_episodes=0)
+        assert metadata.total_episodes == 0
+
+
+class TestAnimeSearchResult:
+    """Tests for AnimeSearchResult model"""
+
+    def test_create_search_result_full(self):
+        """Test creating search result with all fields"""
+        metadata = AnimeMetadata(
+            synopsis="Test",
+            genres=["Action"],
+            rating="8.0/10"
+        )
+        result = AnimeSearchResult(
+            title="Test Anime",
+            url="https://example.com/anime",
+            cover_image="https://example.com/cover.jpg",
+            type="search_result",
+            metadata=metadata
+        )
+        assert result.title == "Test Anime"
+        assert result.url == "https://example.com/anime"
+        assert result.cover_image == "https://example.com/cover.jpg"
+        assert result.type == "search_result"
+        assert result.metadata is not None
+        assert result.metadata.synopsis == "Test"
+
+    def test_create_search_result_minimal(self):
+        """Test creating minimal search result"""
+        result = AnimeSearchResult(
+            title="Minimal Anime",
+            url="https://example.com/minimal",
+            type="direct"
+        )
+        assert result.title == "Minimal Anime"
+        assert result.url == "https://example.com/minimal"
+        assert result.type == "direct"
+        assert result.cover_image is None
+        assert result.metadata is None
+
+    def test_search_result_invalid_type(self):
+        """Test that invalid type raises ValidationError"""
+        with pytest.raises(ValidationError):
+            AnimeSearchResult(
+                title="Test",
+                url="https://example.com",
+                type="invalid_type"  # Must be specific types
+            )
+
+    def test_search_result_empty_title(self):
+        """Test that empty title raises ValidationError"""
+        with pytest.raises(ValidationError):
+            AnimeSearchResult(
+                title="",
+                url="https://example.com",
+                type="search_result"
+            )
+
+    def test_search_result_invalid_url(self):
+        """Test that invalid URL raises ValidationError"""
+        with pytest.raises(ValidationError):
+            AnimeSearchResult(
+                title="Test",
+                url="not-a-url",
+                type="search_result"
+            )