refactor: replace try-except blocks with contextlib.suppress for cleaner error handling across multiple files

nanobot/agent/context.py

@@ -3,6 +3,7 @@
 import base64
 import mimetypes
 import platform
+from contextlib import suppress
 from importlib.resources import files as pkg_files
 from pathlib import Path
 from typing import Any
@@ -121,12 +122,10 @@ class ContextBuilder:
     @staticmethod
     def _is_template_content(content: str, template_path: str) -> bool:
         """Check if *content* is identical to the bundled template (user hasn't customized it)."""
-        try:
+        with suppress(Exception):
             tpl = pkg_files("nanobot") / "templates" / template_path
             if tpl.is_file():
                 return content.strip() == tpl.read_text(encoding="utf-8").strip()
-        except Exception:
-            pass
         return False
 
     def build_messages(

nanobot/agent/loop.py

@@ -7,7 +7,7 @@ import dataclasses
 import json
 import os
 import time
-from contextlib import AsyncExitStack, nullcontext
+from contextlib import AsyncExitStack, nullcontext, suppress
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Awaitable, Callable
 
@@ -492,10 +492,8 @@ class AgentLoop:
         tasks = self._active_tasks.pop(key, [])
         cancelled = sum(1 for t in tasks if not t.done() and t.cancel())
         for t in tasks:
-            try:
+            with suppress(asyncio.CancelledError, Exception):
                 await t
-            except (asyncio.CancelledError, Exception):
-                pass
         sub_cancelled = await self.subagents.cancel_by_session(key)
         return cancelled + sub_cancelled
 

nanobot/agent/memory.py

@@ -7,6 +7,7 @@ import json
 import os
 import re
 import weakref
+from contextlib import suppress
 import tiktoken
 from datetime import datetime
 from pathlib import Path
@@ -296,10 +297,8 @@ class MemoryStore:
     def _next_cursor(self) -> int:
         """Read the current cursor counter and return the next value."""
         if self._cursor_file.exists():
-            try:
+            with suppress(ValueError, OSError):
                 return int(self._cursor_file.read_text(encoding="utf-8").strip()) + 1
-            except (ValueError, OSError):
-                pass
         # Fast path: trust the tail when intact.  Otherwise scan the whole
         # file and take ``max`` — that stays correct even if the monotonic
         # invariant was broken by external writes.
@@ -328,7 +327,7 @@ class MemoryStore:
     def _read_entries(self) -> list[dict[str, Any]]:
         """Read all entries from history.jsonl."""
         entries: list[dict[str, Any]] = []
-        try:
+        with suppress(FileNotFoundError):
             with open(self.history_file, "r", encoding="utf-8") as f:
                 for line in f:
                     line = line.strip()
@@ -337,8 +336,7 @@ class MemoryStore:
                             entries.append(json.loads(line))
                         except json.JSONDecodeError:
                             continue
-        except FileNotFoundError:
+
-            pass
         return entries
 
     def _read_last_entry(self) -> dict[str, Any] | None:
@@ -374,14 +372,12 @@ class MemoryStore:
             # On Windows, opening a directory with O_RDONLY raises
             # PermissionError — skip the dir sync there (NTFS
             # journals metadata synchronously).
-            try:
+            with suppress(PermissionError):
                 fd = os.open(str(self.history_file.parent), os.O_RDONLY)
                 try:
                     os.fsync(fd)
                 finally:
                     os.close(fd)
-            except PermissionError:
-                pass  # Windows — directory fsync not supported
         except BaseException:
             tmp_path.unlink(missing_ok=True)
             raise
@@ -390,10 +386,8 @@ class MemoryStore:
 
     def get_last_dream_cursor(self) -> int:
         if self._dream_cursor_file.exists():
-            try:
+            with suppress(ValueError, OSError):
                 return int(self._dream_cursor_file.read_text(encoding="utf-8").strip())
-            except (ValueError, OSError):
-                pass
         return 0
 
     def set_last_dream_cursor(self, cursor: int) -> None:

nanobot/agent/runner.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import asyncio
 import inspect
 import os
+from contextlib import suppress
 from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Any
@@ -752,12 +753,10 @@ class AgentRunner:
         prepare_call = getattr(spec.tools, "prepare_call", None)
         tool, params, prep_error = None, tool_call.arguments, None
         if callable(prepare_call):
-            try:
+            with suppress(Exception):
                 prepared = prepare_call(tool_call.name, tool_call.arguments)
                 if isinstance(prepared, tuple) and len(prepared) == 3:
                     tool, params, prep_error = prepared
-            except Exception:
-                pass
         if prep_error:
             event = {
                 "name": tool_call.name,

nanobot/agent/tools/mcp.py

@@ -4,7 +4,7 @@ import asyncio
 import os
 import re
 import shutil
-from contextlib import AsyncExitStack
+from contextlib import AsyncExitStack, suppress
 from typing import Any
 
 import httpx
@@ -609,10 +609,8 @@ async def connect_mcp_servers(
                     "only JSON-RPC to stdout and sends logs/debug output to stderr instead."
                 )
             logger.error("MCP server '{}': failed to connect: {}{}", name, e, hint)
-            try:
+            with suppress(Exception):
                 await server_stack.aclose()
-            except Exception:
-                pass
             return name, None
 
     server_stacks: dict[str, AsyncExitStack] = {}

nanobot/agent/tools/search.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import fnmatch
 import os
 import re
+from contextlib import suppress
 from pathlib import Path, PurePosixPath
 from typing import Any, Iterable, TypeVar
 
@@ -92,10 +93,8 @@ class _SearchTool(_FsTool):
 
     def _display_path(self, target: Path, root: Path) -> str:
         if self._workspace:
-            try:
+            with suppress(ValueError):
                 return target.relative_to(self._workspace).as_posix()
-            except ValueError:
-                pass
         return target.relative_to(root).as_posix()
 
     def _iter_files(self, root: Path) -> Iterable[Path]:

nanobot/agent/tools/shell.py

@@ -5,6 +5,7 @@ import os
 import re
 import shutil
 import sys
+from contextlib import suppress
 from pathlib import Path
 from typing import Any
 
@@ -212,9 +213,8 @@ class ExecTool(Tool):
         """Kill a subprocess and reap it to prevent zombies."""
         process.kill()
         try:
-            await asyncio.wait_for(process.wait(), timeout=5.0)
+            with suppress(asyncio.TimeoutError):
-        except asyncio.TimeoutError:
+                await asyncio.wait_for(process.wait(), timeout=5.0)
-            pass
         finally:
             if not _IS_WINDOWS:
                 try:

nanobot/channels/discord.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import asyncio
 import importlib.util
 import time
+from contextlib import suppress
 from dataclasses import dataclass
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Literal
@@ -564,10 +565,8 @@ class DiscordChannel(BaseChannel):
         # Delayed working indicator (cosmetic — not tied to subagent lifecycle)
         async def _delayed_working_emoji() -> None:
             await asyncio.sleep(self.config.working_emoji_delay)
-            try:
+            with suppress(Exception):
                 await message.add_reaction(self.config.working_emoji)
-            except Exception:
-                pass
 
         self._working_emoji_tasks[channel_id] = asyncio.create_task(_delayed_working_emoji())
 
@@ -771,10 +770,8 @@ class DiscordChannel(BaseChannel):
         if task is None:
             return
         task.cancel()
-        try:
+        with suppress(asyncio.CancelledError):
             await task
-        except asyncio.CancelledError:
-            pass
 
     async def _clear_reactions(self, chat_id: str) -> None:
         """Remove all pending reactions after bot replies."""
@@ -788,10 +785,8 @@ class DiscordChannel(BaseChannel):
             return
         bot_user = self._client.user if self._client else None
         for emoji in (self.config.read_receipt_emoji, self.config.working_emoji):
-            try:
+            with suppress(Exception):
                 await msg_obj.remove_reaction(emoji, bot_user)
-            except Exception:
-                pass
 
     async def _cancel_all_typing(self) -> None:
         """Stop all typing tasks."""

nanobot/channels/email.py

@@ -6,6 +6,7 @@ import imaplib
 import re
 import smtplib
 import ssl
+from contextlib import suppress
 from datetime import date
 from email import policy
 from email.header import decode_header, make_header
@@ -460,10 +461,8 @@ class EmailChannel(BaseChannel):
                 if mark_seen:
                     client.store(imap_id, "+FLAGS", "\\Seen")
         finally:
-            try:
+            with suppress(Exception):
                 client.logout()
-            except Exception:
-                pass
 
     def _collect_self_addresses(self) -> set[str]:
         """Return normalized email addresses owned by this channel instance."""

nanobot/channels/feishu.py

@@ -9,6 +9,7 @@ import threading
 import time
 import uuid
 from collections import OrderedDict
+from contextlib import suppress
 from dataclasses import dataclass
 from typing import Any, Literal
 
@@ -612,12 +613,11 @@ class FeishuChannel(BaseChannel):
         """Callback: store reaction_id after background add-reaction completes."""
         if task.cancelled():
             return
-        try:
+        # Failures already logged by _on_background_task_done.
+        with suppress(Exception):
             reaction_id = task.result()
             if reaction_id:
                 self._reaction_ids[message_id] = reaction_id
-        except Exception:
-            pass  # already logged by _on_background_task_done
         # Trim cache to prevent unbounded growth
         if len(self._reaction_ids) > 500:
             self._reaction_ids.pop(next(iter(self._reaction_ids)))

nanobot/channels/manager.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import asyncio
+from contextlib import suppress
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
 
@@ -220,10 +221,8 @@ class ChannelManager:
         # Stop dispatcher
         if self._dispatch_task:
             self._dispatch_task.cancel()
-            try:
+            with suppress(asyncio.CancelledError):
                 await self._dispatch_task
-            except asyncio.CancelledError:
-                pass
 
         # Stop all channels
         for name, channel in self.channels.items():

nanobot/channels/matrix.py

@@ -5,6 +5,7 @@ import json
 import logging
 import mimetypes
 import time
+from contextlib import suppress
 from dataclasses import dataclass
 from pathlib import Path
 from typing import Any, Literal, TypeAlias
@@ -341,10 +342,8 @@ class MatrixChannel(BaseChannel):
                                        timeout=self.config.sync_stop_grace_seconds)
             except (asyncio.TimeoutError, asyncio.CancelledError):
                 self._sync_task.cancel()
-                try:
+                with suppress(asyncio.CancelledError):
                     await self._sync_task
-                except asyncio.CancelledError:
-                    pass
         if self.client:
             await self.client.close()
 
@@ -609,13 +608,11 @@ class MatrixChannel(BaseChannel):
         """Best-effort typing indicator update."""
         if not self.client:
             return
-        try:
+        with suppress(Exception):
             response = await self.client.room_typing(room_id=room_id, typing_state=typing,
                                                      timeout=TYPING_NOTICE_TIMEOUT_MS)
             if isinstance(response, RoomTypingError):
                 logger.debug("Matrix typing failed for {}: {}", room_id, response)
-        except Exception:
-            pass
 
     async def _start_typing_keepalive(self, room_id: str) -> None:
         """Start periodic typing refresh (spec-recommended keepalive)."""
@@ -625,22 +622,18 @@ class MatrixChannel(BaseChannel):
             return
 
         async def loop() -> None:
-            try:
+            with suppress(asyncio.CancelledError):
                 while self._running:
                     await asyncio.sleep(TYPING_KEEPALIVE_INTERVAL_MS / 1000)
                     await self._set_typing(room_id, True)
-            except asyncio.CancelledError:
-                pass
 
         self._typing_tasks[room_id] = asyncio.create_task(loop())
 
     async def _stop_typing_keepalive(self, room_id: str, *, clear_typing: bool) -> None:
         if task := self._typing_tasks.pop(room_id, None):
             task.cancel()
-            try:
+            with suppress(asyncio.CancelledError):
                 await task
-            except asyncio.CancelledError:
-                pass
         if clear_typing:
             await self._set_typing(room_id, False)
 

nanobot/channels/mochat.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import asyncio
 import json
 from collections import deque
+from contextlib import suppress
 from dataclasses import dataclass, field
 from datetime import datetime
 from typing import Any
@@ -330,10 +331,8 @@ class MochatChannel(BaseChannel):
         await self._cancel_delay_timers()
 
         if self._socket:
-            try:
+            with suppress(Exception):
                 await self._socket.disconnect()
-            except Exception:
-                pass
             self._socket = None
 
         if self._cursor_save_task:
@@ -460,10 +459,8 @@ class MochatChannel(BaseChannel):
             return True
         except Exception as e:
             logger.error("Failed to connect Mochat websocket: {}", e)
-            try:
+            with suppress(Exception):
                 await client.disconnect()
-            except Exception:
-                pass
             self._socket = None
             return False
 

nanobot/channels/msteams.py

@@ -20,7 +20,7 @@ import re
 import tempfile
 import threading
 import time
-from contextlib import contextmanager
+from contextlib import contextmanager, suppress
 from dataclasses import dataclass
 from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
 from typing import TYPE_CHECKING, Any
@@ -712,10 +712,8 @@ class MSTeamsChannel(BaseChannel):
             os.replace(tmp_path, path)
         finally:
             if tmp_path and os.path.exists(tmp_path):
-                try:
+                with suppress(OSError):
                     os.unlink(tmp_path)
-                except OSError:
-                    pass
 
     def _save_refs_locked(self, *, prune: bool = True) -> None:
         """Persist conversation references (caller must hold _refs_guard)."""

nanobot/channels/qq.py

@@ -25,6 +25,7 @@ import os
 import re
 import time
 from collections import deque
+from contextlib import suppress
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Literal
 from urllib.parse import unquote, urlparse
@@ -221,17 +222,13 @@ class QQChannel(BaseChannel):
         """Stop bot and cleanup resources."""
         self._running = False
         if self._client:
-            try:
+            with suppress(Exception):
                 await self._client.close()
-            except Exception:
-                pass
         self._client = None
 
         if self._http:
-            try:
+            with suppress(Exception):
                 await self._http.close()
-            except Exception:
-                pass
         self._http = None
 
         logger.info("QQ bot stopped")
@@ -683,7 +680,5 @@ class QQChannel(BaseChannel):
         finally:
             # Cleanup partial file
             if tmp_path is not None:
-                try:
+                with suppress(Exception):
                     tmp_path.unlink(missing_ok=True)
-                except Exception:
-                    pass

nanobot/channels/telegram.py

@@ -6,6 +6,7 @@ import asyncio
 import re
 import time
 import unicodedata
+from contextlib import suppress
 from dataclasses import dataclass
 from pathlib import Path
 from typing import Any, Literal
@@ -462,10 +463,8 @@ class TelegramChannel(BaseChannel):
         if not msg.metadata.get("_progress", False):
             self._stop_typing(msg.chat_id)
             if reply_to_message_id := msg.metadata.get("message_id"):
-                try:
+                with suppress(ValueError):
                     await self._remove_reaction(msg.chat_id, int(reply_to_message_id))
-                except ValueError:
-                    pass
 
         try:
             chat_id = int(msg.chat_id)
@@ -642,10 +641,8 @@ class TelegramChannel(BaseChannel):
                 return
             self._stop_typing(chat_id)
             if reply_to_message_id := meta.get("message_id"):
-                try:
+                with suppress(ValueError):
                     await self._remove_reaction(chat_id, int(reply_to_message_id))
-                except ValueError:
-                    pass
             thread_kwargs = {}
             if message_thread_id := meta.get("message_thread_id"):
                 thread_kwargs["message_thread_id"] = message_thread_id
@@ -1162,11 +1159,10 @@ class TelegramChannel(BaseChannel):
     async def _typing_loop(self, chat_id: str) -> None:
         """Repeatedly send 'typing' action until cancelled."""
         try:
-            while self._app:
+            with suppress(asyncio.CancelledError):
-                await self._app.bot.send_chat_action(chat_id=int(chat_id), action="typing")
+                while self._app:
-                await asyncio.sleep(4)
+                    await self._app.bot.send_chat_action(chat_id=int(chat_id), action="typing")
-        except asyncio.CancelledError:
+                    await asyncio.sleep(4)
-            pass
         except Exception as e:
             logger.debug("Typing indicator stopped for {}: {}", chat_id, e)
 
@@ -1265,10 +1261,8 @@ class TelegramChannel(BaseChannel):
         button_label = query.data or ""
         await query.answer()
         if query.message:
-            try:
+            with suppress(Exception):
                 await query.message.edit_reply_markup(reply_markup=None)
-            except Exception:
-                pass
         logger.debug("Inline button tap from {}: {}", sender_id, button_label)
         self._start_typing(str(chat_id))
         await self._handle_message(

nanobot/channels/weixin.py

@@ -19,6 +19,7 @@ import re
 import time
 import uuid
 from collections import OrderedDict
+from contextlib import suppress
 from pathlib import Path
 from typing import Any
 from urllib.parse import quote
@@ -211,7 +212,7 @@ class WeixinChannel(BaseChannel):
 
     def _save_state(self) -> None:
         state_file = self._get_state_dir() / "account.json"
-        try:
+        with suppress(Exception):
             data = {
                 "token": self._token,
                 "get_updates_buf": self._get_updates_buf,
@@ -220,8 +221,6 @@ class WeixinChannel(BaseChannel):
                 "base_url": self.config.base_url,
             }
             state_file.write_text(json.dumps(data, ensure_ascii=False))
-        except Exception:
-            pass
 
     # ------------------------------------------------------------------
     # HTTP helpers  (matches api.ts buildHeaders / apiFetch)
@@ -576,10 +575,8 @@ class WeixinChannel(BaseChannel):
         # Process messages (WeixinMessage[] from types.ts)
         msgs: list[dict] = data.get("msgs", []) or []
         for msg in msgs:
-            try:
+            with suppress(Exception):
                 await self._process_message(msg)
-            except Exception:
-                pass
 
     # ------------------------------------------------------------------
     # Inbound message processing  (matches inbound.ts + process-message.ts)
@@ -932,10 +929,8 @@ class WeixinChannel(BaseChannel):
                 await asyncio.sleep(TYPING_KEEPALIVE_INTERVAL_S)
                 if stop_event.is_set():
                     break
-                try:
+                with suppress(Exception):
                     await self._send_typing(user_id, typing_ticket, TYPING_STATUS_TYPING)
-                except Exception:
-                    pass
         finally:
             pass
 
@@ -962,16 +957,12 @@ class WeixinChannel(BaseChannel):
             return
 
         typing_ticket = ""
-        try:
+        with suppress(Exception):
             typing_ticket = await self._get_typing_ticket(msg.chat_id, ctx_token)
-        except Exception:
-            typing_ticket = ""
 
         if typing_ticket:
-            try:
+            with suppress(Exception):
                 await self._send_typing(msg.chat_id, typing_ticket, TYPING_STATUS_TYPING)
-            except Exception:
-                pass
 
         typing_keepalive_stop = asyncio.Event()
         typing_keepalive_task: asyncio.Task | None = None
@@ -1043,16 +1034,12 @@ class WeixinChannel(BaseChannel):
             if typing_keepalive_task:
                 typing_keepalive_stop.set()
                 typing_keepalive_task.cancel()
-                try:
+                with suppress(asyncio.CancelledError):
                     await typing_keepalive_task
-                except asyncio.CancelledError:
-                    pass
 
             if typing_ticket and not is_progress:
-                try:
+                with suppress(Exception):
                     await self._send_typing(msg.chat_id, typing_ticket, TYPING_STATUS_CANCEL)
-                except Exception:
-                    pass
 
     async def _start_typing(self, chat_id: str, context_token: str = "") -> None:
         """Start typing indicator immediately when a message is received."""
@@ -1076,10 +1063,8 @@ class WeixinChannel(BaseChannel):
                     await asyncio.sleep(TYPING_KEEPALIVE_INTERVAL_S)
                     if stop_event.is_set():
                         break
-                    try:
+                    with suppress(Exception):
                         await self._send_typing(chat_id, ticket, TYPING_STATUS_TYPING)
-                    except Exception:
-                        pass
             finally:
                 pass
 
@@ -1095,10 +1080,8 @@ class WeixinChannel(BaseChannel):
             if stop_event:
                 stop_event.set()
             task.cancel()
-            try:
+            with suppress(asyncio.CancelledError):
                 await task
-            except asyncio.CancelledError:
-                pass
         if not clear_remote:
             return
         entry = self._typing_tickets.get(chat_id)
@@ -1339,13 +1322,11 @@ def _encrypt_aes_ecb(data: bytes, aes_key_b64: str) -> bytes:
     pad_len = 16 - len(data) % 16
     padded = data + bytes([pad_len] * pad_len)
 
-    try:
+    with suppress(ImportError):
         from Crypto.Cipher import AES
 
         cipher = AES.new(key, AES.MODE_ECB)
         return cipher.encrypt(padded)
-    except ImportError:
-        pass
 
     try:
         from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
@@ -1371,13 +1352,11 @@ def _decrypt_aes_ecb(data: bytes, aes_key_b64: str) -> bytes:
 
     decrypted: bytes | None = None
 
-    try:
+    with suppress(ImportError):
         from Crypto.Cipher import AES
 
         cipher = AES.new(key, AES.MODE_ECB)
         decrypted = cipher.decrypt(data)
-    except ImportError:
-        pass
 
     if decrypted is None:
         try:

nanobot/channels/whatsapp.py

@@ -8,6 +8,7 @@ import os
 import secrets
 import shutil
 import subprocess
+from contextlib import suppress
 from collections import OrderedDict
 from pathlib import Path
 from typing import Any, Literal
@@ -47,10 +48,8 @@ def _load_or_create_bridge_token(path: Path) -> str:
     path.parent.mkdir(parents=True, exist_ok=True)
     token = secrets.token_urlsafe(32)
     path.write_text(token, encoding="utf-8")
-    try:
+    with suppress(OSError):
         path.chmod(0o600)
-    except OSError:
-        pass
     return token
 
 

nanobot/cli/commands.py

@@ -5,7 +5,7 @@ import os
 import select
 import signal
 import sys
-from contextlib import nullcontext
+from contextlib import nullcontext, suppress
 from pathlib import Path
 from typing import Any
 
@@ -14,11 +14,9 @@ if sys.platform == "win32":
     if sys.stdout.encoding != "utf-8":
         os.environ["PYTHONIOENCODING"] = "utf-8"
         # Re-open stdout/stderr with UTF-8 encoding
-        try:
+        with suppress(Exception):
             sys.stdout.reconfigure(encoding="utf-8", errors="replace")
             sys.stderr.reconfigure(encoding="utf-8", errors="replace")
-        except Exception:
-            pass
 
 import typer
 from loguru import logger
@@ -83,35 +81,29 @@ def _flush_pending_tty_input() -> None:
     except Exception:
         return
 
-    try:
+    with suppress(Exception):
         import termios
 
         termios.tcflush(fd, termios.TCIFLUSH)
         return
-    except Exception:
-        pass
 
-    try:
+    with suppress(Exception):
         while True:
             ready, _, _ = select.select([fd], [], [], 0)
             if not ready:
                 break
             if not os.read(fd, 4096):
                 break
-    except Exception:
-        return
 
 
 def _restore_terminal() -> None:
     """Restore terminal to its original state (echo, line buffering, etc.)."""
     if _SAVED_TERM_ATTRS is None:
         return
-    try:
+    with suppress(Exception):
         import termios
 
         termios.tcsetattr(sys.stdin.fileno(), termios.TCSADRAIN, _SAVED_TERM_ATTRS)
-    except Exception:
-        pass
 
 
 def _init_prompt_session() -> None:
@@ -119,12 +111,10 @@ def _init_prompt_session() -> None:
     global _PROMPT_SESSION, _SAVED_TERM_ATTRS
 
     # Save terminal state so we can restore it on exit
-    try:
+    with suppress(Exception):
         import termios
 
         _SAVED_TERM_ATTRS = termios.tcgetattr(sys.stdin.fileno())
-    except Exception:
-        pass
 
     from nanobot.config.paths import get_cli_history_path
 
@@ -936,10 +926,8 @@ def _run_gateway(
                     config.gateway.host or "127.0.0.1", port
                 )
                 writer.close()
-                try:
+                with suppress(Exception):
                     await writer.wait_closed()
-                except Exception:
-                    pass
                 break
             except OSError:
                 await asyncio.sleep(0.1)
@@ -1520,10 +1508,8 @@ def _login_openai_codex() -> None:
         from oauth_cli_kit import get_token, login_oauth_interactive
 
         token = None
-        try:
+        with suppress(Exception):
             token = get_token()
-        except Exception:
-            pass
         if not (token and token.access):
             console.print("[cyan]Starting interactive OAuth login...[/cyan]\n")
             token = login_oauth_interactive(

nanobot/command/builtin.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import asyncio
 import os
 import sys
+from contextlib import suppress
 
 from nanobot import __version__
 from nanobot.bus.events import OutboundMessage
@@ -50,16 +51,15 @@ async def cmd_status(ctx: CommandContext) -> OutboundMessage:
     loop = ctx.loop
     session = ctx.session or loop.sessions.get_or_create(ctx.key)
     ctx_est = 0
-    try:
+    with suppress(Exception):
         ctx_est, _ = loop.consolidator.estimate_session_prompt_tokens(session)
-    except Exception:
-        pass
     if ctx_est <= 0:
         ctx_est = loop._last_usage.get("prompt_tokens", 0)
 
     # Fetch web search provider usage (best-effort, never blocks the response)
     search_usage_text: str | None = None
-    try:
+    # Never let usage fetch break /status
+    with suppress(Exception):
         from nanobot.utils.searchusage import fetch_search_usage
         web_cfg = getattr(loop, "web_config", None)
         search_cfg = getattr(web_cfg, "search", None) if web_cfg else None
@@ -68,14 +68,10 @@ async def cmd_status(ctx: CommandContext) -> OutboundMessage:
             api_key = getattr(search_cfg, "api_key", "") or None
             usage = await fetch_search_usage(provider=provider, api_key=api_key)
             search_usage_text = usage.format()
-    except Exception:
-        pass  # Never let usage fetch break /status
     active_tasks = loop._active_tasks.get(ctx.key, [])
     task_count = sum(1 for t in active_tasks if not t.done())
-    try:
+    with suppress(Exception):
         task_count += loop.subagents.get_running_count_by_session(ctx.key)
-    except Exception:
-        pass
     return OutboundMessage(
         channel=ctx.msg.channel,
         chat_id=ctx.msg.chat_id,

nanobot/providers/base.py

@@ -4,6 +4,7 @@ import asyncio
 import json
 import re
 from abc import ABC, abstractmethod
+from contextlib import suppress
 from collections.abc import Awaitable, Callable
 from dataclasses import dataclass, field
 from datetime import datetime, timezone
@@ -643,14 +644,12 @@ class LLMProvider(ABC):
                         return value
             return None
 
-        try:
+        with suppress(TypeError, ValueError):
             retry_ms = _header_value("retry-after-ms")
             if retry_ms is not None:
                 value = float(retry_ms) / 1000.0
                 if value > 0:
                     return value
-        except (TypeError, ValueError):
-            pass
 
         retry_after = _header_value("retry-after")
         if retry_after is None:

nanobot/providers/github_copilot_provider.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import time
 import webbrowser
 from collections.abc import Callable
+from contextlib import suppress
 
 import httpx
 from oauth_cli_kit.models import OAuthToken
@@ -86,10 +87,8 @@ def login_github_copilot(
         printer(f"Open: {verify_url}")
         printer(f"Code: {user_code}")
         if verify_complete:
-            try:
+            with suppress(Exception):
                 webbrowser.open(verify_complete)
-            except Exception:
-                pass
 
         deadline = time.time() + expires_in
         current_interval = interval

nanobot/security/network.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import ipaddress
 import re
 import socket
+from contextlib import suppress
 from urllib.parse import urlparse
 
 _BLOCKED_NETWORKS = [
@@ -30,10 +31,8 @@ def configure_ssrf_whitelist(cidrs: list[str]) -> None:
     global _allowed_networks
     nets = []
     for cidr in cidrs:
-        try:
+        with suppress(ValueError):
             nets.append(ipaddress.ip_network(cidr, strict=False))
-        except ValueError:
-            pass
     _allowed_networks = nets
 
 

nanobot/session/manager.py

@@ -3,6 +3,7 @@
 import json
 import os
 import shutil
+from contextlib import suppress
 from dataclasses import dataclass, field
 from datetime import datetime
 from pathlib import Path
@@ -362,15 +363,11 @@ class SessionManager:
                     if data.get("_type") == "metadata":
                         metadata = data.get("metadata", {})
                         if data.get("created_at"):
-                            try:
+                            with suppress(ValueError, TypeError):
                                 created_at = datetime.fromisoformat(data["created_at"])
-                            except (ValueError, TypeError):
-                                pass
                         if data.get("updated_at"):
-                            try:
+                            with suppress(ValueError, TypeError):
                                 updated_at = datetime.fromisoformat(data["updated_at"])
-                            except (ValueError, TypeError):
-                                pass
                         last_consolidated = data.get("last_consolidated", 0)
                     else:
                         messages.append(data)
@@ -440,14 +437,12 @@ class SessionManager:
                 # On Windows, opening a directory with O_RDONLY raises
                 # PermissionError — skip the dir sync there (NTFS
                 # journals metadata synchronously).
-                try:
+                with suppress(PermissionError):
                     fd = os.open(str(path.parent), os.O_RDONLY)
                     try:
                         os.fsync(fd)
                     finally:
                         os.close(fd)
-                except PermissionError:
-                    pass  # Windows — directory fsync not supported
         except BaseException:
             tmp_path.unlink(missing_ok=True)
             raise

nanobot/skills/skill-creator/scripts/package_skill.py

@@ -12,25 +12,23 @@ Example:
 
 import sys
 import zipfile
+from contextlib import suppress
 from pathlib import Path
 
 from quick_validate import validate_skill
 
 
 def _is_within(path: Path, root: Path) -> bool:
-    try:
+    with suppress(ValueError):
         path.relative_to(root)
         return True
-    except ValueError:
+    return False
-        return False
 
 
 def _cleanup_partial_archive(skill_filename: Path) -> None:
-    try:
+    if skill_filename.exists():
-        if skill_filename.exists():
+        with suppress(OSError):
             skill_filename.unlink()
-    except OSError:
-        pass
 
 
 def package_skill(skill_path, output_dir=None):

nanobot/utils/helpers.py

@@ -6,6 +6,7 @@ import re
 import shutil
 import time
 import uuid
+from contextlib import suppress
 from datetime import datetime
 from pathlib import Path
 from typing import Any
@@ -416,14 +417,10 @@ def estimate_prompt_tokens_chain(
     """Estimate prompt tokens via provider counter first, then tiktoken fallback."""
     provider_counter = getattr(provider, "estimate_prompt_tokens", None)
     if callable(provider_counter):
-        try:
+        with suppress(Exception):
             tokens, source = provider_counter(messages, tools, model)
             if isinstance(tokens, (int, float)) and tokens > 0:
                 return int(tokens), str(source or "provider_counter")
-        except Exception:
-            pass
-
-    estimated = estimate_prompt_tokens(messages, tools)
     if estimated > 0:
         return int(estimated), "tiktoken"
     return 0, "none"

nanobot/utils/restart.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import json
 import os
 import time
+from contextlib import suppress
 from dataclasses import dataclass, field
 from typing import Any
 
@@ -26,11 +27,9 @@ def format_restart_completed_message(started_at_raw: str) -> str:
     """Build restart completion text and include elapsed time when available."""
     elapsed_suffix = ""
     if started_at_raw:
-        try:
+        with suppress(ValueError):
             elapsed_s = max(0.0, time.time() - float(started_at_raw))
             elapsed_suffix = f" in {elapsed_s:.1f}s"
-        except ValueError:
-            pass
     return f"Restart completed{elapsed_suffix}."