From 9100e91652786866dc3233755f1de9f506c3825d Mon Sep 17 00:00:00 2001
From: Arnav Naval <arnav.naval@gmail.com>
Date: Wed, 6 May 2026 18:30:34 -0500
Subject: [PATCH] [arnav] clean up unused imports and dead local variables

Auto-fixed 52 ruff F401 findings (unused imports) across 22 files
in backend/ and backend/tests/. Manually resolved 8 F841 unused
locals that ruff flagged as unsafe-fix:

- agent_manager.resume_session: drop dead hours_since_closed block.
- main.py mcp-meta + outputs-meta activate handlers: drop dead
  reason = body.get("reason") binding (server ignores the field).
- dashboards.seed_demo, tools_lib.m365_device_login: keep _load(...)
  call for its 404 side-effect, drop unused binding, add intent
  comment.
- outputs.auto_run_output: keep `import anthropic` as availability
  probe, mark with `# noqa: F401` and explanation.
- dead_code_scan._extract_ws_event_branches: drop vestigial
  ws_handler_lines set (never written or read).
- test_browser_agent_unit.test_hash_tool_call_falls_back_to_repr:
  drop the unused _Boom class+instance (the actual self-referential
  bait is bad_input/bad_result; _Boom was never passed to the
  function under test).

Result: 1184/1184 backend tests pass (1 deselected: pre-existing
sandbox-only git test). ruff --select F401,F811,F841 backend/ now
clean (was 60 findings).

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 backend/apps/agents/agent_manager.py              | 9 ---------
 backend/apps/agents/agents.py                     | 5 +----
 backend/apps/agents/browser_agent.py              | 1 -
 backend/apps/agents/tools/web.py                  | 1 -
 backend/apps/dashboards/dashboards.py             | 5 +----
 backend/apps/health/health.py                     | 2 +-
 backend/apps/nine_router.py                       | 1 -
 backend/apps/outputs/outputs.py                   | 4 ++--
 backend/apps/service/buffer.py                    | 2 +-
 backend/apps/skills/skills.py                     | 1 -
 backend/apps/subscription/router.py               | 4 +---
 backend/apps/tools_lib/tools_lib.py               | 4 +---
 backend/auth.py                                   | 2 +-
 backend/main.py                                   | 3 ---
 backend/scripts/dead_code_scan.py                 | 1 -
 backend/tests/conftest.py                         | 4 +---
 backend/tests/test_agent_manager_unit.py          | 4 +---
 backend/tests/test_agents_lifespan_integration.py | 2 --
 backend/tests/test_api_outputs.py                 | 1 -
 backend/tests/test_browser_agent_integration.py   | 3 +--
 backend/tests/test_browser_agent_unit.py          | 6 ------
 backend/tests/test_disconnect_resilience.py       | 2 --
 backend/tests/test_mcp_preflight.py               | 3 +--
 backend/tests/test_phase1_stress.py               | 3 +--
 backend/tests/test_service_legacy.py              | 4 +---
 backend/tests/test_v2_invariants.py               | 4 +---
 backend/tests/test_v2_label_logic.py              | 1 -
 27 files changed, 16 insertions(+), 66 deletions(-)

diff --git a/backend/apps/agents/agent_manager.py b/backend/apps/agents/agent_manager.py
index 470954f1..4e716638 100644
--- a/backend/apps/agents/agent_manager.py
+++ b/backend/apps/agents/agent_manager.py
@@ -801,7 +801,6 @@ class AgentManager:
         )
         self.sessions[session_id] = session
 
-        from backend.apps.service.service import APP_VERSION
 
         await ws_manager.send_to_session(session_id, "agent:status", {
             "session_id": session_id,
@@ -4101,14 +4100,6 @@ class AgentManager:
 
         session = AgentSession(**data)
 
-        hours_since_closed = 0
-        if data.get("closed_at"):
-            try:
-                closed = datetime.fromisoformat(data["closed_at"][:19])
-                hours_since_closed = round((datetime.now() - closed).total_seconds() / 3600, 1)
-            except Exception:
-                pass
-
         session.closed_at = None
         self.sessions[session_id] = session
 
diff --git a/backend/apps/agents/agents.py b/backend/apps/agents/agents.py
index de5ec34d..2a5d99b4 100644
--- a/backend/apps/agents/agents.py
+++ b/backend/apps/agents/agents.py
@@ -1,11 +1,8 @@
 from backend.config.Apps import SubApp
 from backend.apps.agents.agent_manager import agent_manager
-from backend.apps.agents.ws_manager import ws_manager
 from backend.apps.agents.models import AgentConfig, ApprovalResponse
 from contextlib import asynccontextmanager
-from fastapi import WebSocket, WebSocketDisconnect, HTTPException
-from fastapi.responses import JSONResponse
-import json
+from fastapi import HTTPException
 import logging
 
 logger = logging.getLogger(__name__)
diff --git a/backend/apps/agents/browser_agent.py b/backend/apps/agents/browser_agent.py
index 0346e7a5..97591d39 100644
--- a/backend/apps/agents/browser_agent.py
+++ b/backend/apps/agents/browser_agent.py
@@ -13,7 +13,6 @@ import time
 from datetime import datetime
 from uuid import uuid4
 
-import anthropic
 
 from backend.apps.agents.models import AgentSession, ApprovalRequest, Message
 from backend.apps.agents.ws_manager import ws_manager
diff --git a/backend/apps/agents/tools/web.py b/backend/apps/agents/tools/web.py
index c358f47c..0609e3b2 100644
--- a/backend/apps/agents/tools/web.py
+++ b/backend/apps/agents/tools/web.py
@@ -4,7 +4,6 @@ from __future__ import annotations
 
 import html
 import re
-from typing import Any
 
 import httpx
 
diff --git a/backend/apps/dashboards/dashboards.py b/backend/apps/dashboards/dashboards.py
index ba502dd1..fd532204 100644
--- a/backend/apps/dashboards/dashboards.py
+++ b/backend/apps/dashboards/dashboards.py
@@ -11,9 +11,6 @@ from backend.apps.dashboards.models import (
     DashboardCreate,
     DashboardUpdate,
     DashboardLayout,
-    CardPosition,
-    ViewCardPosition,
-    BrowserCardPosition,
 )
 from fastapi import HTTPException
 
@@ -131,7 +128,7 @@ async def create_dashboard(body: DashboardCreate):
 @dashboards.router.post("/{dashboard_id}/seed-demo")
 async def seed_demo(dashboard_id: str):
     """Create a pre-populated demo session for onboarding."""
-    dashboard = _load(dashboard_id)
+    _load(dashboard_id)  # 404s if the dashboard doesn't exist
 
     session_id = uuid4().hex
     now = datetime.now()
diff --git a/backend/apps/health/health.py b/backend/apps/health/health.py
index 1ffbddfd..f80be804 100644
--- a/backend/apps/health/health.py
+++ b/backend/apps/health/health.py
@@ -3,7 +3,7 @@ from contextlib import asynccontextmanager
 from fastapi.responses import PlainTextResponse
 from typeguard import typechecked
 import debug
-from fastapi import status, HTTPException
+from fastapi import status
 
 @asynccontextmanager
 async def health_lifespan():
diff --git a/backend/apps/nine_router.py b/backend/apps/nine_router.py
index a8a3cc52..6534b135 100644
--- a/backend/apps/nine_router.py
+++ b/backend/apps/nine_router.py
@@ -70,7 +70,6 @@ def _find_9router_dir() -> str | None:
 
     if _is_packaged:
         # Packaged Electron app — router is in extraResources
-        import sys
         # In packaged mode, backend is at <resources>/backend/
         # So router is at <resources>/router/
         _resources = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
diff --git a/backend/apps/outputs/outputs.py b/backend/apps/outputs/outputs.py
index 24876f77..1c8ef4f9 100644
--- a/backend/apps/outputs/outputs.py
+++ b/backend/apps/outputs/outputs.py
@@ -6,7 +6,7 @@ import mimetypes
 import base64
 from datetime import datetime
 from contextlib import asynccontextmanager
-from fastapi import HTTPException, Query
+from fastapi import HTTPException
 from fastapi.responses import Response
 from backend.auth import get_auth_token
 from jsonschema import validate as schema_validate, ValidationError as SchemaValidationError
@@ -410,7 +410,7 @@ Every required field must be present. Use realistic, meaningful data.\
 async def auto_run_output(body: AutoRunRequest):
     """Use an LLM to generate input data matching the schema, then optionally execute backend code."""
     try:
-        import anthropic
+        import anthropic  # noqa: F401  -- availability probe; client built below via helper
     except ImportError:
         return {"error": "anthropic SDK not installed", "input_data": None, "backend_result": None}
 
diff --git a/backend/apps/service/buffer.py b/backend/apps/service/buffer.py
index 964c36b6..42ddd060 100644
--- a/backend/apps/service/buffer.py
+++ b/backend/apps/service/buffer.py
@@ -19,7 +19,7 @@ import os
 import sqlite3
 import threading
 from contextlib import contextmanager
-from typing import Iterator, Optional
+from typing import Iterator
 
 logger = logging.getLogger(__name__)
 
diff --git a/backend/apps/skills/skills.py b/backend/apps/skills/skills.py
index c9393d2d..0bfa0526 100644
--- a/backend/apps/skills/skills.py
+++ b/backend/apps/skills/skills.py
@@ -2,7 +2,6 @@ import os
 import json
 import logging
 import re
-from pathlib import Path
 from contextlib import asynccontextmanager
 from fastapi import HTTPException
 from backend.config.Apps import SubApp
diff --git a/backend/apps/subscription/router.py b/backend/apps/subscription/router.py
index 7c91e77c..a82adca5 100644
--- a/backend/apps/subscription/router.py
+++ b/backend/apps/subscription/router.py
@@ -2,9 +2,7 @@
 
 from __future__ import annotations
 
-import json
 import logging
-import os
 from contextlib import asynccontextmanager
 from typing import Optional
 
@@ -14,7 +12,7 @@ from pydantic import BaseModel
 
 from backend.config.Apps import SubApp
 from backend.apps.settings.credentials import OPENSWARM_DEFAULT_PROXY_URL
-from backend.apps.settings.settings import SETTINGS_FILE, load_settings, save_settings_async
+from backend.apps.settings.settings import load_settings, save_settings_async
 
 logger = logging.getLogger(__name__)
 
diff --git a/backend/apps/tools_lib/tools_lib.py b/backend/apps/tools_lib/tools_lib.py
index ba0cfd52..28d8b0d2 100644
--- a/backend/apps/tools_lib/tools_lib.py
+++ b/backend/apps/tools_lib/tools_lib.py
@@ -1,5 +1,4 @@
 import asyncio
-import hashlib
 import json
 import os
 import re
@@ -16,7 +15,6 @@ import httpx
 from dotenv import load_dotenv
 from fastapi import HTTPException, Query
 from fastapi.responses import HTMLResponse
-from pydantic import BaseModel
 from backend.config.Apps import SubApp
 from backend.apps.tools_lib.models import ToolDefinition, ToolCreate, ToolUpdate, BUILTIN_TOOLS
 
@@ -937,7 +935,7 @@ async def m365_device_login(tool_id: str):
     """
     import subprocess
 
-    tool = _load(tool_id)
+    _load(tool_id)  # 404s if the tool doesn't exist
     script = _m365_server_script()
     if not os.path.isfile(script):
         raise HTTPException(status_code=500, detail="M365 MCP server not installed")
diff --git a/backend/auth.py b/backend/auth.py
index f93a0925..1e3eb558 100644
--- a/backend/auth.py
+++ b/backend/auth.py
@@ -29,7 +29,7 @@ import logging
 import os
 import secrets
 
-from backend.config.paths import AUTH_TOKEN_FILE, DATA_ROOT
+from backend.config.paths import AUTH_TOKEN_FILE
 
 logger = logging.getLogger(__name__)
 
diff --git a/backend/main.py b/backend/main.py
index 7532374e..38b1097e 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -345,7 +345,6 @@ async def subscriptions_callback(request: Request):
 async def browser_agent_run(request: Request):
     """Run one or more browser sub-agents in parallel.
     Called by the browser_agent_mcp_server stdio subprocess."""
-    from backend.apps.settings.settings import load_settings
     from backend.apps.agents.browser_agent import run_browser_agents
 
     body = await request.json()
@@ -482,7 +481,6 @@ async def mcp_meta(action: str, request: Request):
 
     if action == "activate":
         server_name = (body.get("server_name") or "").strip()
-        reason = body.get("reason") or ""
         if not server_name:
             return JSONResponse({"error": "server_name is required"}, status_code=400)
         if not parent_session_id:
@@ -663,7 +661,6 @@ async def outputs_meta(action: str, request: Request):
 
     if action == "activate":
         output_id = (body.get("output_id") or "").strip()
-        reason = body.get("reason") or ""
         if not output_id:
             return JSONResponse({"error": "output_id is required"}, status_code=400)
         if not parent_session_id:
diff --git a/backend/scripts/dead_code_scan.py b/backend/scripts/dead_code_scan.py
index db00e5f4..d100ff00 100644
--- a/backend/scripts/dead_code_scan.py
+++ b/backend/scripts/dead_code_scan.py
@@ -539,7 +539,6 @@ def _extract_ws_event_branches(tree: ast.Module) -> list[tuple[str, str]]:
     listenable events.
     """
     out: list[tuple[str, str]] = []
-    ws_handler_lines: set[int] = set()
 
     def _has_ws_decorator(fn: ast.FunctionDef | ast.AsyncFunctionDef) -> bool:
         for dec in fn.decorator_list:
diff --git a/backend/tests/conftest.py b/backend/tests/conftest.py
index 4cea8fce..7914e38b 100644
--- a/backend/tests/conftest.py
+++ b/backend/tests/conftest.py
@@ -28,13 +28,11 @@ What's done here:
 
 from __future__ import annotations
 
-import asyncio
 import os
 import shutil
-import sys
 import tempfile
 from typing import Iterator
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock
 
 import pytest
 
diff --git a/backend/tests/test_agent_manager_unit.py b/backend/tests/test_agent_manager_unit.py
index 24121c07..c3e63b87 100644
--- a/backend/tests/test_agent_manager_unit.py
+++ b/backend/tests/test_agent_manager_unit.py
@@ -29,10 +29,8 @@ can write directly to a `tmp_path` without leaking into siblings.
 from __future__ import annotations
 
 import asyncio
-import json
 import os
-from datetime import datetime, timedelta
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import MagicMock
 
 import pytest
 
diff --git a/backend/tests/test_agents_lifespan_integration.py b/backend/tests/test_agents_lifespan_integration.py
index 3c11c7b8..f3ad723f 100644
--- a/backend/tests/test_agents_lifespan_integration.py
+++ b/backend/tests/test_agents_lifespan_integration.py
@@ -24,10 +24,8 @@ endpoint. This file fills in branches that those don't:
 from __future__ import annotations
 
 import asyncio
-import os
 from unittest.mock import AsyncMock, MagicMock, patch
 
-import pytest
 
 from backend.apps.agents import agents as agents_mod
 from backend.apps.agents.agent_manager import (
diff --git a/backend/tests/test_api_outputs.py b/backend/tests/test_api_outputs.py
index 3eefce82..66997160 100644
--- a/backend/tests/test_api_outputs.py
+++ b/backend/tests/test_api_outputs.py
@@ -25,7 +25,6 @@ import json
 import os
 import sys
 
-import pytest
 
 
 # ---------------------------------------------------------------------------
diff --git a/backend/tests/test_browser_agent_integration.py b/backend/tests/test_browser_agent_integration.py
index 08711e0f..6fc6f194 100644
--- a/backend/tests/test_browser_agent_integration.py
+++ b/backend/tests/test_browser_agent_integration.py
@@ -32,10 +32,9 @@ All tests:
 
 from __future__ import annotations
 
-import asyncio
 from types import SimpleNamespace
 from typing import Any
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import AsyncMock, MagicMock
 
 import pytest
 
diff --git a/backend/tests/test_browser_agent_unit.py b/backend/tests/test_browser_agent_unit.py
index f8195a3e..2f0e7ef2 100644
--- a/backend/tests/test_browser_agent_unit.py
+++ b/backend/tests/test_browser_agent_unit.py
@@ -126,12 +126,6 @@ def test_hash_tool_call_falls_back_to_repr_on_serialization_failure():
     """Self-referential dicts trip json.dumps even with default=str.
     The except branch must still return a (str, str, str) tuple."""
 
-    class _Boom:
-        def __repr__(self) -> str:
-            return "<Boom>"
-
-    boom = _Boom()
-    # Self-referential dict — json.dumps raises ValueError with default=str
     bad_input: dict = {"x": 1}
     bad_input["self"] = bad_input
 
diff --git a/backend/tests/test_disconnect_resilience.py b/backend/tests/test_disconnect_resilience.py
index 38a567f3..7b65ea99 100644
--- a/backend/tests/test_disconnect_resilience.py
+++ b/backend/tests/test_disconnect_resilience.py
@@ -31,9 +31,7 @@ import asyncio
 import json
 import os
 import random
-import sys
 import tempfile
-from typing import Any
 from unittest.mock import patch
 
 import pytest
diff --git a/backend/tests/test_mcp_preflight.py b/backend/tests/test_mcp_preflight.py
index 90bb7133..62b8fd1d 100644
--- a/backend/tests/test_mcp_preflight.py
+++ b/backend/tests/test_mcp_preflight.py
@@ -24,9 +24,8 @@ Coverage targets:
 from __future__ import annotations
 
 import asyncio
-import json
 from types import SimpleNamespace
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import AsyncMock, patch
 
 import pytest
 
diff --git a/backend/tests/test_phase1_stress.py b/backend/tests/test_phase1_stress.py
index efbb341c..46aff6a3 100644
--- a/backend/tests/test_phase1_stress.py
+++ b/backend/tests/test_phase1_stress.py
@@ -13,8 +13,7 @@ import os
 import random
 import string
 import tempfile
-from typing import Any
-from unittest.mock import patch, AsyncMock
+from unittest.mock import patch
 
 import pytest
 
diff --git a/backend/tests/test_service_legacy.py b/backend/tests/test_service_legacy.py
index 1187f809..21803451 100644
--- a/backend/tests/test_service_legacy.py
+++ b/backend/tests/test_service_legacy.py
@@ -13,8 +13,6 @@ Run with:
 import json
 import os
 import tempfile
-from unittest.mock import AsyncMock, MagicMock, patch
-from uuid import uuid4
 
 import pytest
 
@@ -136,7 +134,7 @@ def last_sync(kind: str) -> dict:
 
 # Import application modules (after fixtures are wired).
 from backend.apps.service.client import record
-from backend.apps.agents.models import AgentConfig, AgentSession, Message, ApprovalRequest
+from backend.apps.agents.models import AgentConfig, Message
 from backend.apps.agents.agent_manager import AgentManager
 
 
diff --git a/backend/tests/test_v2_invariants.py b/backend/tests/test_v2_invariants.py
index 49a93b90..304ff1d0 100644
--- a/backend/tests/test_v2_invariants.py
+++ b/backend/tests/test_v2_invariants.py
@@ -24,10 +24,8 @@ import asyncio
 import json
 import os
 import random
-import string
 import tempfile
-from typing import Any
-from unittest.mock import patch, AsyncMock, MagicMock
+from unittest.mock import patch, AsyncMock
 
 import pytest
 
diff --git a/backend/tests/test_v2_label_logic.py b/backend/tests/test_v2_label_logic.py
index 6e7759ad..1e0a0913 100644
--- a/backend/tests/test_v2_label_logic.py
+++ b/backend/tests/test_v2_label_logic.py
@@ -16,7 +16,6 @@ from __future__ import annotations
 
 import random
 import re
-import pytest
 
 
 # ===========================================================================