feat(rpc): page stable message histories

python/omp-rpc/src/omp_rpc/protocol.py

@@ -851,9 +851,20 @@ class SessionStats:
 
 @dataclass(slots=True, frozen=True)
 class ReadyEvent:
+    protocol_version: int | None = None
+    supported_protocol_versions: tuple[int, ...] | None = None
+    max_frame_bytes: int | None = None
+    max_reassembled_frame_bytes: int | None = None
     type: Literal["ready"] = "ready"
 
 
+@dataclass(slots=True, frozen=True)
+class MessagesPage:
+    messages: tuple[AgentMessage, ...]
+    total_messages: int
+    next_cursor: str | None
+
+
 @dataclass(slots=True, frozen=True)
 class ExtensionUiRequest:
     id: str
@@ -1490,7 +1501,23 @@ def parse_extension_error(payload: JsonObject) -> ExtensionError:
 def parse_notification(payload: JsonObject) -> RpcNotification:
     event_type = payload.get("type")
     if event_type == "ready":
-        return ReadyEvent()
+        raw_versions = payload.get("supportedProtocolVersions")
+        supported_versions: tuple[int, ...] | None = None
+        if raw_versions is not None:
+            if not isinstance(raw_versions, list) or any(
+                not isinstance(version, int) or isinstance(version, bool)
+                for version in raw_versions
+            ):
+                raise ValueError("ready.supportedProtocolVersions must be integers")
+            supported_versions = tuple(raw_versions)
+        return ReadyEvent(
+            protocol_version=_optional_int(payload, "protocolVersion"),
+            supported_protocol_versions=supported_versions,
+            max_frame_bytes=_optional_int(payload, "maxFrameBytes"),
+            max_reassembled_frame_bytes=_optional_int(
+                payload, "maxReassembledFrameBytes"
+            ),
+        )
     if event_type == "extension_ui_request":
         return parse_extension_ui_request(payload)
     if event_type == "extension_error":