refactor(chat): drop alternate streaming entry path; use graph_stream

surfsense_backend/app/tasks/chat/streaming/graph_stream/__init__.py

@@ -0,0 +1,21 @@
+"""LangGraph ``astream_events`` → SSE (``stream_output`` + ``StreamingResult``).
+
+Imports are lazy to avoid a circular import with ``relay.event_relay``.
+"""
+
+from __future__ import annotations
+
+__all__ = ["StreamingResult", "stream_output"]
+
+
+def __getattr__(name: str):
+    if name == "stream_output":
+        from app.tasks.chat.streaming.graph_stream.event_stream import stream_output
+
+        return stream_output
+    if name == "StreamingResult":
+        from app.tasks.chat.streaming.graph_stream.result import StreamingResult
+
+        return StreamingResult
+    msg = f"module {__name__!r} has no attribute {name!r}"
+    raise AttributeError(msg)

surfsense_backend/app/tasks/chat/streaming/graph_stream/event_stream.py

@@ -0,0 +1,53 @@
+"""Run LangGraph event streams through ``EventRelay``."""
+
+from __future__ import annotations
+
+from collections.abc import AsyncIterator
+from typing import Any
+
+from app.agents.new_chat.feature_flags import get_flags
+from app.tasks.chat.streaming.graph_stream.result import StreamingResult
+from app.tasks.chat.streaming.relay.event_relay import EventRelay
+from app.tasks.chat.streaming.relay.state import AgentEventRelayState
+
+
+async def stream_output(
+    *,
+    agent: Any,
+    config: dict[str, Any],
+    input_data: Any,
+    streaming_service: Any,
+    result: StreamingResult,
+    step_prefix: str = "thinking",
+    initial_step_id: str | None = None,
+    initial_step_title: str = "",
+    initial_step_items: list[str] | None = None,
+    content_builder: Any | None = None,
+    runtime_context: Any = None,
+) -> AsyncIterator[str]:
+    """Yield SSE frames from agent ``astream_events`` via ``EventRelay``."""
+    state = AgentEventRelayState.for_invocation(
+        initial_step_id=initial_step_id,
+        initial_step_title=initial_step_title,
+        initial_step_items=initial_step_items,
+        parity_v2=bool(get_flags().enable_stream_parity_v2),
+    )
+
+    astream_kwargs: dict[str, Any] = {"config": config, "version": "v2"}
+    if runtime_context is not None:
+        astream_kwargs["context"] = runtime_context
+
+    events = agent.astream_events(input_data, **astream_kwargs)
+    relay = EventRelay(streaming_service=streaming_service)
+    async for frame in relay.relay(
+        events,
+        state=state,
+        result=result,
+        step_prefix=step_prefix,
+        content_builder=content_builder,
+        config=config,
+    ):
+        yield frame
+
+    result.accumulated_text = state.accumulated_text
+    result.agent_called_update_memory = state.called_update_memory

surfsense_backend/app/tasks/chat/streaming/graph_stream/result.py

@@ -0,0 +1,28 @@
+"""Mutable facts collected while relaying one agent stream (``stream_output``)."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from typing import Any
+
+
+@dataclass
+class StreamingResult:
+    accumulated_text: str = ""
+    is_interrupted: bool = False
+    interrupt_value: dict[str, Any] | None = None
+    sandbox_files: list[str] = field(default_factory=list)
+    agent_called_update_memory: bool = False
+    request_id: str | None = None
+    turn_id: str = ""
+    filesystem_mode: str = "cloud"
+    client_platform: str = "web"
+    intent_detected: str = "chat_only"
+    intent_confidence: float = 0.0
+    write_attempted: bool = False
+    write_succeeded: bool = False
+    verification_succeeded: bool = False
+    commit_gate_passed: bool = True
+    commit_gate_reason: str = ""
+    assistant_message_id: int | None = None
+    content_builder: Any | None = field(default=None, repr=False)