import asyncio import json import logging from fastapi import WebSocket from backend.apps.agents.core.seq_log import TERMINAL_STATUSES, seq_log logger = logging.getLogger(__name__) class ConnectionManager: """Manages WebSocket connections and HITL approval bridging; events flow through seq_log so reconnects can replay.""" def __init__(self): self.connections: dict[str, list[WebSocket]] = {} self.global_connections: list[WebSocket] = [] self.pending_futures: dict[str, asyncio.Future] = {} self.browser_futures: dict[str, asyncio.Future] = {} async def connect_session(self, session_id: str, websocket: WebSocket): await websocket.accept() if session_id not in self.connections: self.connections[session_id] = [] self.connections[session_id].append(websocket) async def connect_global(self, websocket: WebSocket): await websocket.accept() self.global_connections.append(websocket) def disconnect_session(self, session_id: str, websocket: WebSocket): if session_id in self.connections: self.connections[session_id] = [ ws for ws in self.connections[session_id] if ws != websocket ] if not self.connections[session_id]: del self.connections[session_id] def disconnect_global(self, websocket: WebSocket): self.global_connections = [ ws for ws in self.global_connections if ws != websocket ] async def send_to_session(self, session_id: str, event: str, data: dict): """Broadcast a session event with monotonic sequencing; terminal statuses also persist to disk.""" async with seq_log.stamp(session_id, event, data) as (seq, payload_str): for ws in list(self.connections.get(session_id, [])): try: await ws.send_text(payload_str) except Exception: logger.debug("send_to_session: send failed (will retry on reconnect)", exc_info=True) for ws in list(self.global_connections): try: await ws.send_text(payload_str) except Exception: logger.debug("send_to_session: global send failed", exc_info=True) # Persist under the lock so a concurrent running status can't race past and overwrite with stale state. if event == "agent:status" and data.get("status") in TERMINAL_STATUSES: seq_log.persist_terminal(session_id, payload_str) async def replay_to( self, session_id: str, websocket: WebSocket, last_seq: int ) -> dict: """Replay buffered events with seq > last_seq; returns ack envelope for the resume handshake.""" oldest, newest, events = seq_log.replay(session_id, last_seq) # Gap-check first: if last_seq predates the buffer, signal REST-refresh; last_seq=0 means fresh client (full replay). if last_seq > 0 and oldest is not None and last_seq < oldest - 1: gap_payload = json.dumps({ "event": "agent:gap_detected", "session_id": session_id, "data": { "session_id": session_id, "oldest_seq": oldest, "newest_seq": newest, "client_seq": last_seq, }, }) try: await websocket.send_text(gap_payload) except Exception: pass return { "ok": False, "reason": "gap", "oldest_seq": oldest, "newest_seq": newest, } if events: # Drop already-resolved approval requests from the replay. The # ring buffer holds every event we ever stamped, including the # original `agent:approval_request`. Without this filter, a # client that reconnects (e.g. after navigating away and back, # which re-mounts AgentChat with last_seq=0) re-fires every # past approval as if it were live, but the backing future was # popped from pending_futures the moment the user answered, so # the resurrected card is a dead no-op. Lifecycle is simple: # send_approval_request() inserts into pending_futures BEFORE # the event is stamped, and resolve_approval()/timeout/cancel # all pop it; so "in pending_futures" is the authoritative # is-still-live signal for the request_id. A process restart # wipes pending_futures, which is correct because # reconcile_on_startup also marks waiting_approval sessions as # stopped so there's nothing to answer anyway. events = self._filter_stale_approvals(events) events = self._strip_replayed_closes(events) for s in events: try: await websocket.send_text(s) except Exception: logger.debug("replay_to: send failed", exc_info=True) break return { "ok": True, "replayed": len(events), "from_seq": last_seq, "to_seq": newest, } terminal = seq_log.load_terminal(session_id) if terminal is not None: try: await websocket.send_text(terminal) except Exception: pass return {"ok": True, "replayed": 1, "terminal_only": True} return { "ok": True, "replayed": 0, "current_seq": newest if newest is not None else 0, } def _strip_replayed_closes(self, events: list[str]) -> list[str]: """Drop `agent:closed` events from a replay buffer. agent:closed is a transition event ("session JUST closed") whose frontend reducer (closeSessionFromWs) destructively deletes the session from state.sessions. Replaying it on a fresh client (e.g. a user who just clicked the closed chat in history) deletes the session they're trying to open. The current closed state is already conveyed by the REST hydrate (status=stopped, closed_at set) and by the latest agent:status event in the replay, so suppressing the transition replay is non-lossy. """ out: list[str] = [] for payload_str in events: try: parsed = json.loads(payload_str) except (ValueError, TypeError): out.append(payload_str) continue if parsed.get("event") == "agent:closed": continue out.append(payload_str) return out def _filter_stale_approvals(self, events: list[str]) -> list[str]: """Return events minus any `agent:approval_request` whose request_id is no longer in pending_futures. JSON parse is per-event but replay only runs on (re)connect, so it isn't a hot path. """ alive = self.pending_futures out: list[str] = [] for payload_str in events: try: parsed = json.loads(payload_str) except (ValueError, TypeError): out.append(payload_str) continue if parsed.get("event") != "agent:approval_request": out.append(payload_str) continue data = parsed.get("data") or {} request_id = data.get("request_id") if request_id and request_id in alive: out.append(payload_str) return out async def broadcast_global(self, event: str, data: dict): """Send to all dashboard connections; bypasses seq_log (dashboard resumes via full state refetch).""" payload = json.dumps({"event": event, "data": data}) for ws in list(self.global_connections): try: await ws.send_text(payload) except Exception: pass async def send_approval_request( self, session_id: str, request_id: str, tool_name: str, tool_input: dict, timeout: float = 600.0, sensitive_pattern: str | None = None, sensitive_label: str | None = None, sensitive_why: str | None = None, ) -> dict: """Send an approval request and wait for the user's decision; 10-minute timeout prevents permanent park.""" future = asyncio.get_event_loop().create_future() self.pending_futures[request_id] = future payload: dict = { "request_id": request_id, "tool_name": tool_name, "tool_input": tool_input, } if sensitive_pattern: payload["sensitive_pattern"] = sensitive_pattern payload["sensitive_label"] = sensitive_label payload["sensitive_why"] = sensitive_why await self.send_to_session(session_id, "agent:approval_request", payload) try: result = await asyncio.wait_for(future, timeout=timeout) return result except asyncio.TimeoutError: logger.warning("Approval %s for session %s timed out after %ss", request_id, session_id, timeout) return {"behavior": "deny", "message": "Approval timed out"} finally: self.pending_futures.pop(request_id, None) def resolve_approval(self, request_id: str, decision: dict): """Resolve a pending approval Future with the user's decision.""" future = self.pending_futures.get(request_id) if future and not future.done(): future.set_result(decision) async def send_browser_command( self, request_id: str, action: str, browser_id: str, params: dict, tab_id: str = "" ) -> dict: """Send a browser command to the frontend and wait for the result.""" if not self.global_connections: return {"error": "No dashboard is connected. Open the dashboard to use browser tools."} future = asyncio.get_event_loop().create_future() self.browser_futures[request_id] = future await self.broadcast_global("browser:command", { "request_id": request_id, "action": action, "browser_id": browser_id, "tab_id": tab_id, "params": params, }) try: result = await asyncio.wait_for(future, timeout=30.0) return result except asyncio.TimeoutError: return {"error": "Browser command timed out"} finally: self.browser_futures.pop(request_id, None) def resolve_browser_command(self, request_id: str, result: dict): """Resolve a pending browser command Future with the frontend's result.""" future = self.browser_futures.get(request_id) if future and not future.done(): future.set_result(result) ws_manager = ConnectionManager()