feat: add Python 3.10 support

- Lower requires-python from >=3.11 to >=3.10 (aligns with pydantic-ai)
- Add 3.10 to CI test matrix (3.10, 3.11, 3.12, 3.13)
- Replace datetime.UTC (3.11+) with datetime.timezone.utc (all versions)
  across 28 files in src/ and tests/
- Use asyncio.TimeoutError with noqa for ruff UP041 compat
- Update ruff target-version to py310
- Update README, classifiers, and docs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: patrick-chinchill

src/chat_sdk/adapters/discord/adapter.py

@@ -13,7 +13,7 @@
 import os
 import re
 from contextvars import ContextVar
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 from urllib.parse import quote
 
@@ -590,7 +590,7 @@ async def _handle_forwarded_message(
             metadata=MessageMetadata(
                 date_sent=datetime.fromisoformat(data.get("timestamp", ""))
                 if data.get("timestamp")
-                else datetime.now(UTC),
+                else datetime.now(timezone.utc),
                 edited=False,
             ),
             attachments=[
@@ -1239,7 +1239,9 @@ def _parse_discord_message(self, raw: dict[str, Any], thread_id: str) -> Message
                 is_me=is_me,
             ),
             metadata=MessageMetadata(
-                date_sent=datetime.fromisoformat(msg["timestamp"]) if msg.get("timestamp") else datetime.now(UTC),
+                date_sent=datetime.fromisoformat(msg["timestamp"])
+                if msg.get("timestamp")
+                else datetime.now(timezone.utc),
                 edited=msg.get("edited_timestamp") is not None,
                 edited_at=datetime.fromisoformat(msg["edited_timestamp"]) if msg.get("edited_timestamp") else None,
             ),
@@ -1284,7 +1286,7 @@ async def _create_discord_thread(
         message_id: str,
     ) -> dict[str, str]:
         """Create a Discord thread from a message."""
-        thread_name = f"Thread {datetime.now(UTC).isoformat()}"
+        thread_name = f"Thread {datetime.now(timezone.utc).isoformat()}"
 
         self._logger.debug(
             "Discord API: POST thread",

src/chat_sdk/adapters/github/adapter.py

@@ -16,7 +16,7 @@
 import re
 import time
 from collections.abc import AsyncIterable
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 
 from chat_sdk.adapters.github.cards import card_to_github_markdown
@@ -386,7 +386,7 @@ def _parse_issue_comment(
             metadata=MessageMetadata(
                 date_sent=datetime.fromisoformat(created_at.replace("Z", "+00:00"))
                 if created_at
-                else datetime.now(tz=UTC),
+                else datetime.now(tz=timezone.utc),
                 edited=edited,
                 edited_at=datetime.fromisoformat(updated_at.replace("Z", "+00:00")) if edited and updated_at else None,
             ),
@@ -428,7 +428,7 @@ def _parse_review_comment(
             metadata=MessageMetadata(
                 date_sent=datetime.fromisoformat(created_at.replace("Z", "+00:00"))
                 if created_at
-                else datetime.now(tz=UTC),
+                else datetime.now(tz=timezone.utc),
                 edited=edited,
                 edited_at=datetime.fromisoformat(updated_at.replace("Z", "+00:00")) if edited and updated_at else None,
             ),
@@ -787,7 +787,7 @@ async def list_threads(
                 metadata=MessageMetadata(
                     date_sent=datetime.fromisoformat(pr.get("created_at", "").replace("Z", "+00:00"))
                     if pr.get("created_at")
-                    else datetime.now(tz=UTC),
+                    else datetime.now(tz=timezone.utc),
                     edited=pr.get("created_at") != pr.get("updated_at"),
                 ),
             )

src/chat_sdk/adapters/google_chat/adapter.py

@@ -16,7 +16,7 @@
 import re
 import time
 from collections.abc import AsyncIterable, Awaitable, Callable
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 
 from chat_sdk.adapters.google_chat.cards import card_to_google_card
@@ -2727,9 +2727,9 @@ def _parse_message_metadata(message: dict[str, Any]) -> Any:
         try:
             date_sent = datetime.fromisoformat(create_time.replace("Z", "+00:00"))
         except (ValueError, AttributeError):
-            date_sent = datetime.now(tz=UTC)
+            date_sent = datetime.now(tz=timezone.utc)
     else:
-        date_sent = datetime.now(tz=UTC)
+        date_sent = datetime.now(tz=timezone.utc)
 
     return MessageMetadata(
         date_sent=date_sent,

src/chat_sdk/adapters/linear/adapter.py

@@ -15,7 +15,7 @@
 import os
 import re
 import time
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 
 from chat_sdk.adapters.linear.cards import card_to_linear_markdown
@@ -415,7 +415,7 @@ def _build_message(
             raw=LinearRawMessage(comment=comment),
             author=author,
             metadata=MessageMetadata(
-                date_sent=datetime.fromisoformat(created_at) if created_at else datetime.now(UTC),
+                date_sent=datetime.fromisoformat(created_at) if created_at else datetime.now(timezone.utc),
                 edited=created_at != updated_at,
                 edited_at=datetime.fromisoformat(updated_at) if (created_at != updated_at and updated_at) else None,
             ),
@@ -749,7 +749,9 @@ def _comment_node_to_message(
                 is_me=user_id == self._bot_user_id,
             ),
             metadata=MessageMetadata(
-                date_sent=datetime.fromisoformat(node["createdAt"]) if node.get("createdAt") else datetime.now(UTC),
+                date_sent=datetime.fromisoformat(node["createdAt"])
+                if node.get("createdAt")
+                else datetime.now(timezone.utc),
                 edited=node.get("createdAt") != node.get("updatedAt"),
                 edited_at=(
                     datetime.fromisoformat(node["updatedAt"])
@@ -852,7 +854,7 @@ def parse_message(self, raw: LinearRawMessage) -> Message:
                 is_me=user_id == self._bot_user_id,
             ),
             metadata=MessageMetadata(
-                date_sent=(datetime.fromisoformat(created_at) if created_at else datetime.now(UTC)),
+                date_sent=(datetime.fromisoformat(created_at) if created_at else datetime.now(timezone.utc)),
                 edited=created_at != updated_at,
                 edited_at=(datetime.fromisoformat(updated_at) if created_at != updated_at and updated_at else None),
             ),

src/chat_sdk/adapters/slack/adapter.py

@@ -20,7 +20,7 @@
 from collections import OrderedDict
 from collections.abc import AsyncIterable, Awaitable, Callable
 from contextvars import ContextVar
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 from urllib.parse import parse_qs
 
@@ -1574,14 +1574,14 @@ async def _parse_slack_message(
 
         ts_str = event.get("ts", "0")
         try:
-            date_sent = datetime.fromtimestamp(float(ts_str), tz=UTC)
+            date_sent = datetime.fromtimestamp(float(ts_str), tz=timezone.utc)
         except (ValueError, TypeError, OSError):
-            date_sent = datetime.now(tz=UTC)
+            date_sent = datetime.now(tz=timezone.utc)
 
         edited_at: datetime | None = None
         if event.get("edited"):
             try:
-                edited_at = datetime.fromtimestamp(float(event["edited"].get("ts", "0")), tz=UTC)
+                edited_at = datetime.fromtimestamp(float(event["edited"].get("ts", "0")), tz=timezone.utc)
             except (ValueError, TypeError, OSError):
                 edited_at = None
 
@@ -1616,14 +1616,14 @@ def _parse_slack_message_sync(self, event: dict[str, Any], thread_id: str) -> Me
 
         ts_str = event.get("ts", "0")
         try:
-            date_sent = datetime.fromtimestamp(float(ts_str), tz=UTC)
+            date_sent = datetime.fromtimestamp(float(ts_str), tz=timezone.utc)
         except (ValueError, TypeError, OSError):
-            date_sent = datetime.now(tz=UTC)
+            date_sent = datetime.now(tz=timezone.utc)
 
         edited_at: datetime | None = None
         if event.get("edited"):
             try:
-                edited_at = datetime.fromtimestamp(float(event["edited"].get("ts", "0")), tz=UTC)
+                edited_at = datetime.fromtimestamp(float(event["edited"].get("ts", "0")), tz=timezone.utc)
             except (ValueError, TypeError, OSError):
                 edited_at = None
 
@@ -2585,7 +2585,7 @@ async def list_threads(self, channel_id: str, options: ListThreadsOptions | None
                 last_reply_at: datetime | None = None
                 if msg.get("latest_reply"):
                     try:
-                        last_reply_at = datetime.fromtimestamp(float(msg["latest_reply"]), tz=UTC)
+                        last_reply_at = datetime.fromtimestamp(float(msg["latest_reply"]), tz=timezone.utc)
                     except (ValueError, TypeError, OSError):
                         last_reply_at = None
 

src/chat_sdk/adapters/teams/adapter.py

@@ -13,7 +13,7 @@
 import json
 import os
 import re
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any, NoReturn
 
 from chat_sdk.adapters.teams.cards import card_to_adaptive_card
@@ -529,7 +529,7 @@ def _parse_teams_message(
             metadata=MessageMetadata(
                 date_sent=datetime.fromisoformat(activity["timestamp"])
                 if activity.get("timestamp")
-                else datetime.now(UTC),
+                else datetime.now(timezone.utc),
                 edited=False,
             ),
             attachments=attachments,
@@ -1430,7 +1430,9 @@ def _map_graph_message(self, msg: dict[str, Any], thread_id: str) -> Message:
             ),
             metadata=MessageMetadata(
                 date_sent=(
-                    datetime.fromisoformat(msg["createdDateTime"]) if msg.get("createdDateTime") else datetime.now(UTC)
+                    datetime.fromisoformat(msg["createdDateTime"])
+                    if msg.get("createdDateTime")
+                    else datetime.now(timezone.utc)
                 ),
                 edited=bool(msg.get("lastModifiedDateTime")),
             ),

src/chat_sdk/adapters/telegram/adapter.py

@@ -17,7 +17,7 @@
 import os
 import re
 from dataclasses import dataclass
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 
 from chat_sdk.adapters.telegram.cards import (
@@ -944,7 +944,7 @@ async def edit_message(
                 metadata=MessageMetadata(
                     date_sent=existing.metadata.date_sent,
                     edited=True,
-                    edited_at=datetime.now(UTC),
+                    edited_at=datetime.now(timezone.utc),
                 ),
                 attachments=existing.attachments,
                 is_mention=existing.is_mention,
@@ -1259,9 +1259,9 @@ def parse_telegram_message(
             raw=raw,
             author=author,
             metadata=MessageMetadata(
-                date_sent=datetime.fromtimestamp(raw["date"], tz=UTC),
+                date_sent=datetime.fromtimestamp(raw["date"], tz=timezone.utc),
                 edited=edit_date is not None,
-                edited_at=(datetime.fromtimestamp(edit_date, tz=UTC) if edit_date is not None else None),
+                edited_at=(datetime.fromtimestamp(edit_date, tz=timezone.utc) if edit_date is not None else None),
             ),
             attachments=self.extract_attachments(raw),
             is_mention=self.is_bot_mentioned(raw, plain_text),

src/chat_sdk/adapters/whatsapp/adapter.py

@@ -15,7 +15,7 @@
 import os
 import time
 from collections.abc import AsyncIterable
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 from urllib.parse import parse_qs, urlparse
 
@@ -525,7 +525,7 @@ def _build_message(
             metadata=MessageMetadata(
                 date_sent=datetime.fromtimestamp(
                     int(inbound.get("timestamp", "0")),
-                    tz=UTC,
+                    tz=timezone.utc,
                 ),
                 edited=False,
             ),
@@ -981,7 +981,7 @@ def parse_message(self, raw: WhatsAppRawMessage) -> Message:
             metadata=MessageMetadata(
                 date_sent=datetime.fromtimestamp(
                     int(raw["message"].get("timestamp", "0")),
-                    tz=UTC,
+                    tz=timezone.utc,
                 ),
                 edited=False,
             ),

src/chat_sdk/channel.py

@@ -9,7 +9,7 @@
 
 from collections.abc import AsyncIterator
 from dataclasses import dataclass
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 
 from chat_sdk.errors import ChatNotImplementedError
@@ -444,7 +444,7 @@ async def _remove_reaction(emoji: EmojiValue | str) -> None:
                 is_me=True,
             ),
             metadata=MessageMetadata(
-                date_sent=datetime.now(tz=UTC),
+                date_sent=datetime.now(tz=timezone.utc),
                 edited=False,
             ),
             attachments=attachments,

src/chat_sdk/chat.py

@@ -14,7 +14,7 @@
 import uuid
 from collections.abc import Awaitable, Callable
 from dataclasses import dataclass
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from typing import Any
 
 from chat_sdk.channel import ChannelImpl
@@ -1143,7 +1143,7 @@ async def _handle_action_event(self, event: ActionEvent) -> None:
                 formatted={"type": "root", "children": []},
                 raw=event.raw,
                 author=event.user,
-                metadata=MessageMetadata(date_sent=datetime.now(tz=UTC), edited=False),
+                metadata=MessageMetadata(date_sent=datetime.now(tz=timezone.utc), edited=False),
                 attachments=[],
             )
             thread = self._create_thread(event.adapter, event.thread_id, dummy_message, is_subscribed)
@@ -1175,7 +1175,7 @@ async def _open_modal(modal: Any) -> dict[str, str] | None:
                                 metadata=getattr(
                                     raw_fetched,
                                     "metadata",
-                                    MessageMetadata(date_sent=datetime.now(tz=UTC), edited=False),
+                                    MessageMetadata(date_sent=datetime.now(tz=timezone.utc), edited=False),
                                 ),
                             )
                     except Exception:
@@ -1253,7 +1253,7 @@ async def _handle_reaction_event(self, event: ReactionEvent) -> None:
                 formatted={"type": "root", "children": []},
                 raw=None,
                 author=event.user,
-                metadata=MessageMetadata(date_sent=datetime.now(tz=UTC), edited=False),
+                metadata=MessageMetadata(date_sent=datetime.now(tz=timezone.utc), edited=False),
             ),
             is_subscribed,
         )
@@ -1314,7 +1314,7 @@ async def open_dm(self, user: str | Author) -> ThreadImpl:
                 formatted={"type": "root", "children": []},
                 raw=None,
                 author=Author(user_id="", user_name="", full_name="", is_bot=False, is_me=False),
-                metadata=MessageMetadata(date_sent=datetime.now(tz=UTC), edited=False),
+                metadata=MessageMetadata(date_sent=datetime.now(tz=timezone.utc), edited=False),
             ),
             False,
         )
@@ -1559,7 +1559,7 @@ async def _handle_queue_or_debounce(
                 )
                 return
 
-            now = int(datetime.now(tz=UTC).timestamp() * 1000)
+            now = int(datetime.now(tz=timezone.utc).timestamp() * 1000)
             entry = QueueEntry(
                 message=message,
                 enqueued_at=now,
@@ -1577,7 +1577,7 @@ async def _handle_queue_or_debounce(
 
         try:
             if strategy == "debounce":
-                now = int(datetime.now(tz=UTC).timestamp() * 1000)
+                now = int(datetime.now(tz=timezone.utc).timestamp() * 1000)
                 await self._state_adapter.enqueue(
                     lock_key,
                     QueueEntry(message=message, enqueued_at=now, expires_at=now + queue_entry_ttl_ms),
@@ -1634,7 +1634,7 @@ async def _debounce_loop(
                 break
 
             msg = self._rehydrate_message(entry.message)
-            now = int(datetime.now(tz=UTC).timestamp() * 1000)
+            now = int(datetime.now(tz=timezone.utc).timestamp() * 1000)
             if now > entry.expires_at:
                 self._logger.info("message-expired", {"thread_id": thread_id, "message_id": msg.id})
                 continue
@@ -1664,7 +1664,7 @@ async def _drain_queue(
                 if entry is None:
                     break
                 msg = self._rehydrate_message(entry.message)
-                now = int(datetime.now(tz=UTC).timestamp() * 1000)
+                now = int(datetime.now(tz=timezone.utc).timestamp() * 1000)
                 if now <= entry.expires_at:
                     pending.append((msg, entry.expires_at))
                 else:
@@ -1869,7 +1869,7 @@ def _rehydrate_message(self, raw: Any) -> Message:
             if isinstance(date_sent, str):
                 date_sent = datetime.fromisoformat(date_sent)
             elif not isinstance(date_sent, datetime):
-                date_sent = datetime.now(tz=UTC)
+                date_sent = datetime.now(tz=timezone.utc)
 
             edited_at = metadata_raw.get("edited_at")
             if isinstance(edited_at, str):
@@ -1930,7 +1930,7 @@ def _message_from_json(data: dict[str, Any]) -> Message:
     if isinstance(date_sent, str):
         date_sent = datetime.fromisoformat(date_sent)
     elif not isinstance(date_sent, datetime):
-        date_sent = datetime.now(tz=UTC)
+        date_sent = datetime.now(tz=timezone.utc)
 
     edited_at = metadata_raw.get("editedAt") or metadata_raw.get("edited_at")
     if isinstance(edited_at, str):