diff --git a/frontend/sidebar.py b/frontend/sidebar.py
index 1a6b9d4..82de7b0 100644
--- a/frontend/sidebar.py
+++ b/frontend/sidebar.py
@@ -240,10 +240,10 @@ def render_filetree_arborist(tree):
     selected = tree_view(
         data=data,
         icons={"open": "📂", "closed": "📁"},
-        height=200,
+        height=400,
         selection=None,
         select_internal_nodes=True,  # allow clicking folder names, not just files
-        open_by_default=False
+        open_by_default=True
     )
 
     return selected
diff --git a/tests/test_mcp_server_file_search.py b/tests/test_mcp_server_file_search.py
index e69de29..61481e9 100644
--- a/tests/test_mcp_server_file_search.py
+++ b/tests/test_mcp_server_file_search.py
@@ -0,0 +1,278 @@
+import pytest
+from pathlib import Path
+from backend.agent.servers import mcp_server_file_search as server
+
+
+# =========================================================
+# FIXTURES
+# =========================================================
+
+@pytest.fixture()
+def workspace(tmp_path, monkeypatch):
+    """
+    Erstellt einen isolierten Workspace für jeden Test.
+    """
+    ws = tmp_path / "workspace"
+    ws.mkdir()
+
+    monkeypatch.setattr(server, "ALLOWED_DIR", ws)
+
+    return ws
+
+
+# =========================================================
+# BASIC TESTS (1–10)
+# =========================================================
+
+
+# ---------------------------------------------------------
+# 1. _safe_path erlaubt gültige Pfade
+# ---------------------------------------------------------
+
+def test_safe_path_valid(workspace):
+    result = server._safe_path("test.txt")
+
+    assert result == workspace / "test.txt"
+
+
+# ---------------------------------------------------------
+# 2. _safe_path blockiert Path Traversal
+# ---------------------------------------------------------
+
+def test_safe_path_blocks_traversal(workspace):
+    with pytest.raises(ValueError):
+        server._safe_path("../secret.txt")
+
+
+# ---------------------------------------------------------
+# 3. list_files liefert leeren Hinweis
+# ---------------------------------------------------------
+
+def test_list_files_empty(workspace):
+    result = server.list_files()
+
+    assert result == "No files found in the project directory."
+
+
+# ---------------------------------------------------------
+# 4. list_files findet Dateien rekursiv
+# ---------------------------------------------------------
+
+def test_list_files_recursive(workspace):
+    src = workspace / "src"
+    src.mkdir()
+
+    (src / "main.py").write_text("print('hello')")
+
+    result = server.list_files()
+
+    assert "src/main.py" in result
+
+
+# ---------------------------------------------------------
+# 5. read_file liest Datei korrekt
+# ---------------------------------------------------------
+
+def test_read_file_success(workspace):
+    file = workspace / "hello.txt"
+    file.write_text("Hello World")
+
+    result = server.read_file("hello.txt")
+
+    assert result == "Hello World"
+
+
+# ---------------------------------------------------------
+# 6. read_file erkennt fehlende Datei
+# ---------------------------------------------------------
+
+def test_read_file_missing(workspace):
+    result = server.read_file("missing.txt")
+
+    assert "does not exist" in result
+
+
+# ---------------------------------------------------------
+# 7. write_new_file erstellt Datei
+# ---------------------------------------------------------
+
+def test_write_new_file_success(workspace):
+    result = server.write_new_file("new.txt", "content")
+
+    assert "OK:" in result
+    assert (workspace / "new.txt").exists()
+
+
+# ---------------------------------------------------------
+# 8. write_new_file verhindert Überschreiben
+# ---------------------------------------------------------
+
+def test_write_new_file_existing(workspace):
+    file = workspace / "exists.txt"
+    file.write_text("old")
+
+    result = server.write_new_file("exists.txt", "new")
+
+    assert "already exists" in result
+
+
+# ---------------------------------------------------------
+# 9. create_new_directory erstellt Verzeichnis
+# ---------------------------------------------------------
+
+def test_create_new_directory_success(workspace):
+    result = server.create_new_directory("mydir")
+
+    assert "OK:" in result
+    assert (workspace / "mydir").is_dir()
+
+
+# ---------------------------------------------------------
+# 10. search_files findet Inhalte
+# ---------------------------------------------------------
+
+def test_search_files_content_match(workspace):
+    file = workspace / "notes.txt"
+    file.write_text("Python MCP Server")
+
+    result = server.search_files("mcp")
+
+    assert "[content]" in result
+
+
+# =========================================================
+# EDGE CASE TESTS (11–20)
+# =========================================================
+
+
+# ---------------------------------------------------------
+# 11. Mehrfaches Traversal blockieren
+# ---------------------------------------------------------
+
+def test_safe_path_double_traversal(workspace):
+    with pytest.raises(ValueError):
+        server._safe_path("../../../../etc/passwd")
+
+
+# ---------------------------------------------------------
+# 12. Symlink Escape verhindern
+# ---------------------------------------------------------
+
+def test_safe_path_symlink_escape(workspace):
+    outside = workspace.parent / "outside"
+    outside.mkdir()
+
+    target = outside / "evil.txt"
+    target.write_text("bad")
+
+    link = workspace / "link"
+    link.symlink_to(outside)
+
+    with pytest.raises(ValueError):
+        server._safe_path("link/evil.txt")
+
+
+# ---------------------------------------------------------
+# 13. Dateien ohne Extension blockieren
+# ---------------------------------------------------------
+
+def test_write_file_without_extension(workspace):
+    result = server.write_new_file("README", "test")
+
+    assert "can only write" in result
+
+
+# ---------------------------------------------------------
+# 14. Hidden Files blockieren
+# ---------------------------------------------------------
+
+def test_write_hidden_file(workspace):
+    result = server.write_new_file(".env", "SECRET=123")
+
+    assert "can only write" in result
+
+
+# ---------------------------------------------------------
+# 15. Binary Files korrekt behandeln
+# ---------------------------------------------------------
+
+def test_read_binary_file(workspace):
+    binary = workspace / "data.bin"
+    binary.write_bytes(b"\xFF\xFE\xFD")
+
+    result = server.read_file("data.bin")
+
+    assert "not a text file" in result
+
+
+# ---------------------------------------------------------
+# 16. Sehr große Zeilen durchsuchen
+# ---------------------------------------------------------
+
+def test_search_huge_line(workspace):
+    huge_text = "A" * 1_000_000 + "needle"
+
+    file = workspace / "huge.txt"
+    file.write_text(huge_text)
+
+    result = server.search_files("needle")
+
+    assert "[content]" in result
+
+
+# ---------------------------------------------------------
+# 17. Leere Dateien lesen
+# ---------------------------------------------------------
+
+def test_read_empty_file(workspace):
+    file = workspace / "empty.txt"
+    file.write_text("")
+
+    result = server.read_file("empty.txt")
+
+    assert result == ""
+
+
+# ---------------------------------------------------------
+# 18. Sonderzeichen im Query
+# ---------------------------------------------------------
+
+def test_search_special_characters(workspace):
+    file = workspace / "test.txt"
+    file.write_text("hello [world] (test)")
+
+    result = server.search_files("[world]")
+
+    assert "[content]" in result
+
+
+# ---------------------------------------------------------
+# 19. Unicode-Dateinamen unterstützen
+# ---------------------------------------------------------
+
+def test_write_unicode_filename(workspace):
+    filename = "🔥_überraschung.txt"
+
+    result = server.write_new_file(filename, "unicode")
+
+    assert "OK:" in result
+    assert (workspace / filename).exists()
+
+
+# ---------------------------------------------------------
+# 20. Tiefe Verzeichnisstrukturen
+# ---------------------------------------------------------
+
+def test_list_files_deep_nesting(workspace):
+    current = workspace
+
+    for i in range(50):
+        current = current / f"dir_{i}"
+        current.mkdir()
+
+    file = current / "deep.txt"
+    file.write_text("deep")
+
+    result = server.list_files()
+
+    assert "deep.txt" in result
\ No newline at end of file
diff --git a/tests/test_mcp_server_web_search.py b/tests/test_mcp_server_web_search.py
index e69de29..66835ea 100644
--- a/tests/test_mcp_server_web_search.py
+++ b/tests/test_mcp_server_web_search.py
@@ -0,0 +1,297 @@
+import pytest
+from unittest.mock import Mock, patch
+from backend.agent.servers import mcp_server_web_search as server
+
+
+# =========================================================
+# BASIC TESTS (1–10)
+# =========================================================
+
+
+# ---------------------------------------------------------
+# 1. _validate_url erlaubt HTTPS
+# ---------------------------------------------------------
+
+def test_validate_url_https():
+    url = "https://example.com"
+
+    result = server._validate_url(url)
+
+    assert result == url
+
+
+# ---------------------------------------------------------
+# 2. _validate_url erlaubt HTTP
+# ---------------------------------------------------------
+
+def test_validate_url_http():
+    url = "http://example.com"
+
+    result = server._validate_url(url)
+
+    assert result == url
+
+
+# ---------------------------------------------------------
+# 3. _validate_url blockiert localhost
+# ---------------------------------------------------------
+
+def test_validate_url_localhost():
+    with pytest.raises(ValueError):
+        server._validate_url("http://localhost/admin")
+
+
+# ---------------------------------------------------------
+# 4. _validate_url blockiert 127.0.0.1
+# ---------------------------------------------------------
+
+def test_validate_url_loopback():
+    with pytest.raises(ValueError):
+        server._validate_url("http://127.0.0.1")
+
+
+# ---------------------------------------------------------
+# 5. _validate_url blockiert private IP
+# ---------------------------------------------------------
+
+def test_validate_url_private_ip():
+    with pytest.raises(ValueError):
+        server._validate_url("http://192.168.1.10")
+
+
+# ---------------------------------------------------------
+# 6. web_search liefert Suchergebnisse
+# ---------------------------------------------------------
+
+@patch("ddgs.DDGS")
+def test_web_search_success(mock_ddgs):
+    mock_instance = Mock()
+
+    mock_instance.text.return_value = [
+        {
+            "title": "Example",
+            "href": "https://example.com",
+            "body": "Example snippet"
+        }
+    ]
+
+    mock_ddgs.return_value = mock_instance
+
+    result = server.web_search("example")
+
+    assert "Title: Example" in result
+    assert "https://example.com" in result
+
+
+# ---------------------------------------------------------
+# 7. web_search ohne Ergebnisse
+# ---------------------------------------------------------
+
+@patch("ddgs.DDGS")
+def test_web_search_no_results(mock_ddgs):
+    mock_instance = Mock()
+    mock_instance.text.return_value = []
+
+    mock_ddgs.return_value = mock_instance
+
+    result = server.web_search("nothing")
+
+    assert "No results found" in result
+
+
+# ---------------------------------------------------------
+# 8. fetch_page lädt HTML
+# ---------------------------------------------------------
+
+@patch("requests.get")
+def test_fetch_page_success(mock_get):
+    response = Mock()
+
+    response.status_code = 200
+    response.text = """
+    <html>
+        <body>
+            <h1>Hello World</h1>
+        </body>
+    </html>
+    """
+
+    mock_get.return_value = response
+
+    result = server.fetch_page("https://example.com")
+
+    assert "Hello World" in result
+
+
+# ---------------------------------------------------------
+# 9. fetch_page entfernt script Tags
+# ---------------------------------------------------------
+
+@patch("requests.get")
+def test_fetch_page_removes_script(mock_get):
+    response = Mock()
+
+    response.status_code = 200
+    response.text = """
+    <html>
+        <script>alert('xss')</script>
+        <body>Hello</body>
+    </html>
+    """
+
+    mock_get.return_value = response
+
+    result = server.fetch_page("https://example.com")
+
+    assert "alert" not in result
+    assert "Hello" in result
+
+
+# ---------------------------------------------------------
+# 10. fetch_page erkennt HTTP Fehler
+# ---------------------------------------------------------
+
+@patch("requests.get")
+def test_fetch_page_http_error(mock_get):
+    response = Mock()
+
+    response.status_code = 404
+    response.text = "Not Found"
+
+    mock_get.return_value = response
+
+    result = server.fetch_page("https://example.com")
+
+    assert "HTTP error 404" in result
+
+
+# =========================================================
+# EDGE CASE TESTS (11–20)
+# =========================================================
+
+
+# ---------------------------------------------------------
+# 11. Blockiere file:// SSRF
+# ---------------------------------------------------------
+
+def test_validate_url_blocks_file_scheme():
+    with pytest.raises(ValueError):
+        server._validate_url("file:///etc/passwd")
+
+
+# ---------------------------------------------------------
+# 12. Blockiere ftp://
+# ---------------------------------------------------------
+
+def test_validate_url_blocks_ftp():
+    with pytest.raises(ValueError):
+        server._validate_url("ftp://example.com")
+
+
+# ---------------------------------------------------------
+# 13. Blockiere AWS Metadata Endpoint
+# ---------------------------------------------------------
+
+def test_validate_url_blocks_metadata_ip():
+    with pytest.raises(ValueError):
+        server._validate_url("http://169.254.169.254")
+
+
+# ---------------------------------------------------------
+# 14. Blockiere internes Docker Netzwerk
+# ---------------------------------------------------------
+
+def test_validate_url_blocks_docker_network():
+    with pytest.raises(ValueError):
+        server._validate_url("http://172.20.0.5")
+
+
+# ---------------------------------------------------------
+# 15. Sehr lange URL
+# ---------------------------------------------------------
+
+def test_validate_url_very_long():
+    long_url = "https://example.com/" + ("a" * 5000)
+
+    result = server._validate_url(long_url)
+
+    assert result == long_url
+
+
+# ---------------------------------------------------------
+# 16. fetch_page behandelt Timeout
+# ---------------------------------------------------------
+
+@patch("requests.get")
+def test_fetch_page_timeout(mock_get):
+    import requests
+
+    mock_get.side_effect = requests.Timeout("timeout")
+
+    result = server.fetch_page("https://example.com")
+
+    assert "Error fetching page" in result
+
+
+# ---------------------------------------------------------
+# 17. fetch_page behandelt Connection Error
+# ---------------------------------------------------------
+
+@patch("requests.get")
+def test_fetch_page_connection_error(mock_get):
+    import requests
+
+    mock_get.side_effect = requests.ConnectionError("connection failed")
+
+    result = server.fetch_page("https://example.com")
+
+    assert "Error fetching page" in result
+
+
+# ---------------------------------------------------------
+# 18. fetch_page truncatet große Seiten
+# ---------------------------------------------------------
+
+@patch("requests.get")
+def test_fetch_page_truncates_large_content(mock_get):
+    response = Mock()
+
+    response.status_code = 200
+    response.text = "<html><body>" + ("A" * 10000) + "</body></html>"
+
+    mock_get.return_value = response
+
+    result = server.fetch_page("https://example.com")
+
+    assert "[... truncated ...]" in result
+
+
+# ---------------------------------------------------------
+# 19. fetch_page bei leerem Body
+# ---------------------------------------------------------
+
+@patch("requests.get")
+def test_fetch_page_empty_content(mock_get):
+    response = Mock()
+
+    response.status_code = 200
+    response.text = "<html></html>"
+
+    mock_get.return_value = response
+
+    result = server.fetch_page("https://example.com")
+
+    assert "no text content found" in result.lower()
+
+
+# ---------------------------------------------------------
+# 20. web_search behandelt Exception sauber
+# ---------------------------------------------------------
+
+@patch("ddgs.DDGS")
+def test_web_search_exception(mock_ddgs):
+    mock_ddgs.side_effect = Exception("DDGS failed")
+
+    result = server.web_search("test")
+
+    assert "Search error" in result
\ No newline at end of file