diff --git a/backend/ai.py b/backend/ai.py
index 3ce2889..07ad0e3 100644
--- a/backend/ai.py
+++ b/backend/ai.py
@@ -5,7 +5,6 @@ Configured via environment variables.
 """
 
 import os
-import json
 import logging
 import httpx
 from typing import Optional, Literal
diff --git a/backend/ai_routes.py b/backend/ai_routes.py
index cb21b86..fb82b1a 100644
--- a/backend/ai_routes.py
+++ b/backend/ai_routes.py
@@ -1,6 +1,6 @@
 """ObsiGate AI — API routes for AI-powered editor features."""
 
-from fastapi import APIRouter, HTTPException, Query
+from fastapi import APIRouter, HTTPException
 from pydantic import BaseModel, Field
 from typing import Optional
 import logging
diff --git a/backend/watcher.py b/backend/watcher.py
index 1281b6c..bc640c4 100644
--- a/backend/watcher.py
+++ b/backend/watcher.py
@@ -1,6 +1,5 @@
 import asyncio
 import logging
-import os
 import time
 from pathlib import Path
 from typing import Callable, Dict, List, Optional
diff --git a/generate_pwa_icons.py b/generate_pwa_icons.py
index 62c1843..8141895 100644
--- a/generate_pwa_icons.py
+++ b/generate_pwa_icons.py
@@ -4,7 +4,6 @@ Generate PWA icons for ObsiGate
 Creates PNG icons in various sizes from an SVG template
 """
 
-import os
 from pathlib import Path
 
 def create_svg_icon(size, output_path):
diff --git a/tests/conftest.py b/tests/conftest.py
index 1405933..4941bf7 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,7 +1,6 @@
 # tests/conftest.py — Shared fixtures for ObsiGate test suite
 import os
 import sys
-import tempfile
 from pathlib import Path
 
 import pytest
@@ -91,7 +90,7 @@ def app_with_vault(test_vault_dir: str):
     backend.main._load_config = lambda: {"watcher_enabled": False}
 
     from backend.main import app
-    from backend.indexer import build_index, vault_config, index
+    from backend.indexer import build_index
     import asyncio
 
     # Build the index
@@ -100,7 +99,7 @@ def app_with_vault(test_vault_dir: str):
     loop.run_until_complete(build_index())
 
     # Build inverted index for search
-    from backend.search import init_inverted_index, _inverted_index
+    from backend.search import init_inverted_index
     init_inverted_index()
 
     client = TestClient(app)
diff --git a/tests/test_api_main.py b/tests/test_api_main.py
index 35dca2f..f6fb126 100644
--- a/tests/test_api_main.py
+++ b/tests/test_api_main.py
@@ -1,6 +1,5 @@
 # tests/test_api_main.py — Integration tests for main.py API endpoints
 # Uses the existing app_with_vault / client fixtures from conftest.py
-import pytest
 
 
 # ═══════════════════════════════════════════════════════════════════
@@ -416,7 +415,7 @@ class TestConfig:
             "search_workers": 4,
         })
         assert resp.status_code == 200
-        data = resp.json()
+        _ = resp.json()
         # POST /api/config returns the updated config object directly
 
     def test_diagnostics(self, client):
@@ -622,8 +621,6 @@ class TestBackupFile:
     def test_backup(self, tmp_path, monkeypatch):
         """Backup is created by save operations"""
         from backend.main import _backup_file
-        from pathlib import Path
-        import os
         monkeypatch.chdir(tmp_path)
         vault = tmp_path / "Vault"
         vault.mkdir()
diff --git a/tests/test_auth.py b/tests/test_auth.py
index 9ba981c..4276738 100644
--- a/tests/test_auth.py
+++ b/tests/test_auth.py
@@ -1,7 +1,4 @@
 # tests/test_auth.py — Tests for authentication and authorization
-import os
-import time
-from unittest.mock import patch
 
 import pytest
 
@@ -70,9 +67,7 @@ class TestJWTHandler:
         from backend.auth.jwt_handler import (
             create_access_token,
             decode_token,
-            ACCESS_TOKEN_EXPIRE_SECONDS,
         )
-        import time
 
         # Override TTL to a value in the past
         user = {"username": "testuser", "role": "user", "vaults": [], "display_name": "X"}
@@ -111,7 +106,6 @@ class TestJWTHandler:
     def test_wrong_type_token(self):
         """decode_token rejects refresh tokens (type != 'access')."""
         from backend.auth.jwt_handler import (
-            create_access_token,
             create_refresh_token,
             decode_token,
         )
@@ -229,7 +223,7 @@ class TestUserStore:
 
 class TestRateLimiter:
     def test_initial_state(self):
-        from backend.ratelimit import is_rate_limited, get_status
+        from backend.ratelimit import get_status
         status = get_status("192.168.1.1")
         assert status["limited"] is False
         assert status["failures"] == 0
@@ -268,7 +262,6 @@ class TestRateLimiter:
 class TestMiddleware:
     def test_is_auth_enabled_logic(self):
         """is_auth_enabled reads OBSIGATE_AUTH_ENABLED env var."""
-        import os
         from backend.auth.middleware import is_auth_enabled
         # The function checks if env var != 'false'
         # In our test env it may be set by fixture — test the logic
diff --git a/tests/test_auth_api.py b/tests/test_auth_api.py
index cf79f88..a19a46c 100644
--- a/tests/test_auth_api.py
+++ b/tests/test_auth_api.py
@@ -9,7 +9,8 @@ import pytest
 @pytest.fixture
 def auth_client():
     """Create a TestClient with auth enabled, isolated temp data."""
-    import tempfile, shutil
+    import tempfile
+    import shutil
     from pathlib import Path
 
     tmp = Path(tempfile.mkdtemp())
@@ -58,7 +59,7 @@ def auth_client():
     backend.main._load_config = lambda: {"watcher_enabled": False}
 
     from backend.main import app
-    from backend.indexer import build_index, vault_config, index
+    from backend.indexer import build_index, index
     import asyncio
 
     for key in list(index.keys()):
diff --git a/tests/test_indexer.py b/tests/test_indexer.py
index 1751e5c..846d48f 100644
--- a/tests/test_indexer.py
+++ b/tests/test_indexer.py
@@ -1,9 +1,7 @@
 # tests/test_indexer.py — Tests for the indexer module
 import os
-import tempfile
 from pathlib import Path
 
-import pytest
 
 from backend.indexer import (
     _extract_tags,
@@ -14,7 +12,6 @@ from backend.indexer import (
     get_vault_names,
     get_vault_data,
     get_backlinks,
-    get_conflicts,
     SUPPORTED_EXTENSIONS,
     _scan_vault,
     load_vault_config,
diff --git a/tests/test_indexer_advanced.py b/tests/test_indexer_advanced.py
index 8e08bf0..7bc30b0 100644
--- a/tests/test_indexer_advanced.py
+++ b/tests/test_indexer_advanced.py
@@ -1,28 +1,17 @@
 # tests/test_indexer_advanced.py — Tests for indexer CRUD operations and hooks
-import asyncio
 from pathlib import Path
 
-import pytest
 
 from backend.indexer import (
-    index,
-    vault_config,
     _file_lookup,
     path_index,
     _index_generation,
-    _on_index_change,
     _add_file_to_structures,
     _remove_file_from_structures,
-    update_single_file,
-    remove_single_file,
-    handle_file_move,
     _index_single_file_sync,
     _ensure_parent_dirs_in_path_index,
     find_file_in_index,
-    get_vault_names,
     set_index_change_hook,
-    _scan_vault,
-    build_index,
 )
 
 
diff --git a/tests/test_modules.py b/tests/test_modules.py
index cb529fc..1c574df 100644
--- a/tests/test_modules.py
+++ b/tests/test_modules.py
@@ -1,10 +1,6 @@
 # tests/test_modules.py — Tests for utility modules: audit, history, ratelimit, settings, webhooks, share
-import os
 import json
 import time
-import tempfile
-from pathlib import Path
-from unittest.mock import patch
 
 import pytest
 
diff --git a/tests/test_search.py b/tests/test_search.py
index c049fea..8bf563d 100644
--- a/tests/test_search.py
+++ b/tests/test_search.py
@@ -9,11 +9,6 @@ from backend.search import (
     _highlight_terms,
     _extract_highlighted_snippet,
     _extract_regex_snippet,
-    get_all_tags,
-    suggest_titles,
-    suggest_tags,
-    search,
-    advanced_search,
 )
 
 
@@ -253,7 +248,7 @@ class TestSuggestAPI:
             data = resp.json()
         except Exception:
             pytest.skip(f"Suggest tags non-JSON: {resp.text[:100]}")
-        tags = [s["tag"] for s in data["suggestions"]]
+        _ = [s["tag"] for s in data["suggestions"]]
         assert len(data["suggestions"]) >= 0  # At minimum, valid response
 
 
diff --git a/tests/test_search_advanced.py b/tests/test_search_advanced.py
index 1e10356..417ad57 100644
--- a/tests/test_search_advanced.py
+++ b/tests/test_search_advanced.py
@@ -3,17 +3,12 @@ import pytest
 from backend.search import (
     InvertedIndex,
     get_inverted_index,
-    init_inverted_index,
     search,
     advanced_search,
     suggest_titles,
     suggest_tags,
     get_all_tags,
-    tokenize,
-    normalize_text,
-    _inverted_index,
 )
-from backend.indexer import index, _add_file_to_structures, _remove_file_from_structures
 
 
 # ═══════════════════════════════════════════════════════════════════
diff --git a/tests/test_watcher.py b/tests/test_watcher.py
index 932418d..46c5ef9 100644
--- a/tests/test_watcher.py
+++ b/tests/test_watcher.py
@@ -2,6 +2,7 @@
 import asyncio
 import os
 from pathlib import Path
+import tempfile
 from unittest.mock import MagicMock, patch, AsyncMock
 
 import pytest
@@ -140,7 +141,8 @@ class TestVaultWatcher:
 class TestOnVaultChange:
     @pytest.fixture
     def setup_vault(self):
-        import tempfile, shutil
+        import tempfile
+        import shutil
         from pathlib import Path
         from backend.indexer import build_index, index
         import asyncio
@@ -181,6 +183,3 @@ class TestOnVaultChange:
         }]
         asyncio.run(_on_vault_change(events))
         # Should not crash
-
-
-import tempfile
\ No newline at end of file