fix: Correct events property return type and add get_index to EventsListBase

- Change ConversationState.events return type from Sequence[Event] to EventsListBase
- Add get_index abstract method to EventsListBase for event lookup by ID
- Implement get_index in RemoteEventsList class

This fixes pyright type errors where code was calling .append() and .get_index()
on state.events, which are not available on Sequence[Event].

Co-authored-by: openhands <openhands@all-hands.dev>

Author: openhands-agent

openhands-sdk/openhands/sdk/conversation/events_list_base.py

@@ -2,6 +2,7 @@
 from collections.abc import Sequence
 
 from openhands.sdk.event import Event
+from openhands.sdk.event.types import EventID
 
 
 class EventsListBase(Sequence[Event], ABC):
@@ -15,3 +16,8 @@ class EventsListBase(Sequence[Event], ABC):
     def append(self, event: Event) -> None:
         """Add a new event to the list."""
         ...
+
+    @abstractmethod
+    def get_index(self, event_id: EventID) -> int:
+        """Return the integer index for a given event_id."""
+        ...

openhands-sdk/openhands/sdk/conversation/impl/remote_conversation.py

@@ -352,6 +352,14 @@ def append(self, event: Event) -> None:
         """Add a new event to the list (for compatibility with EventLog interface)."""
         self.add_event(event)
 
+    def get_index(self, event_id: str) -> int:
+        """Return the integer index for a given event_id."""
+        with self._lock:
+            for idx, event in enumerate(self._cached_events):
+                if event.id == event_id:
+                    return idx
+        raise KeyError(f"Unknown event_id: {event_id}")
+
     def create_default_callback(self) -> ConversationCallbackType:
         """Create a default callback that adds events to this list."""
 

openhands-sdk/openhands/sdk/conversation/state.py

@@ -13,6 +13,7 @@
 from openhands.sdk.conversation.compliance import APIComplianceMonitor
 from openhands.sdk.conversation.conversation_stats import ConversationStats
 from openhands.sdk.conversation.event_store import EventLog
+from openhands.sdk.conversation.events_list_base import EventsListBase
 from openhands.sdk.conversation.fifo_lock import FIFOLock
 from openhands.sdk.conversation.persistence_const import BASE_STATE, EVENTS_DIR
 from openhands.sdk.conversation.secret_registry import SecretRegistry
@@ -213,10 +214,10 @@ def _handle_legacy_fields(cls, data: Any) -> Any:
         return data
 
     @property
-    def events(self) -> Sequence[Event]:
+    def events(self) -> EventsListBase:
         """Read-only view of conversation events.
 
-        Returns events as a Sequence to discourage direct mutation.
+        Returns events as EventsListBase to discourage direct mutation.
         Use add_event() to add new events with compliance monitoring.
         """
         return self._events