33488fd634
Backend: - FastAPI WebSocket /ws endpoint with streaming via LangGraph astream - LangGraph Supervisor connecting 3 mock agents (order_lookup, order_actions, fallback) - YAML Agent Registry with Pydantic validation and immutable configs - PostgresSaver checkpoint persistence via langgraph-checkpoint-postgres - Session TTL with 30-min sliding window and interrupt extension - LLM provider abstraction (Anthropic/OpenAI/Google) - Token usage + cost tracking callback handler - Input validation: message size cap, thread_id format, content length - Security: no hardcoded defaults, startup API key validation, no input reflection Frontend: - React 19 + TypeScript + Vite chat UI - WebSocket hook with reconnect + exponential backoff - Streaming token display with agent attribution - Interrupt approval/reject UI for write operations - Collapsible tool call viewer Testing: - 87 unit tests, 87% coverage (exceeds 80% requirement) - Ruff lint + format clean Infrastructure: - Docker Compose (PostgreSQL 16 + backend) - pyproject.toml with full dependency management
79 lines
2.6 KiB
Python
79 lines
2.6 KiB
Python
"""Session TTL management with sliding window and interrupt extension."""
|
|
|
|
from __future__ import annotations
|
|
|
|
import time
|
|
from dataclasses import dataclass
|
|
|
|
|
|
@dataclass(frozen=True)
|
|
class SessionState:
|
|
thread_id: str
|
|
last_activity: float
|
|
has_pending_interrupt: bool
|
|
|
|
|
|
class SessionManager:
|
|
"""Manages session TTL with sliding window and interrupt extensions.
|
|
|
|
- Each message resets the TTL (sliding window).
|
|
- A pending interrupt suspends expiration until resolved.
|
|
"""
|
|
|
|
def __init__(self, session_ttl_seconds: int = 1800) -> None:
|
|
self._session_ttl = session_ttl_seconds
|
|
self._sessions: dict[str, SessionState] = {}
|
|
|
|
def touch(self, thread_id: str) -> SessionState:
|
|
"""Update last activity for a session (resets sliding window)."""
|
|
existing = self._sessions.get(thread_id)
|
|
new_state = SessionState(
|
|
thread_id=thread_id,
|
|
last_activity=time.time(),
|
|
has_pending_interrupt=existing.has_pending_interrupt if existing else False,
|
|
)
|
|
self._sessions = {**self._sessions, thread_id: new_state}
|
|
return new_state
|
|
|
|
def is_expired(self, thread_id: str) -> bool:
|
|
"""Check if a session has expired."""
|
|
state = self._sessions.get(thread_id)
|
|
if state is None:
|
|
return True
|
|
|
|
if state.has_pending_interrupt:
|
|
return False
|
|
|
|
elapsed = time.time() - state.last_activity
|
|
return elapsed > self._session_ttl
|
|
|
|
def extend_for_interrupt(self, thread_id: str) -> SessionState:
|
|
"""Mark session as having a pending interrupt (suspends TTL)."""
|
|
existing = self._sessions.get(thread_id)
|
|
if existing is None:
|
|
return self.touch(thread_id)
|
|
|
|
new_state = SessionState(
|
|
thread_id=thread_id,
|
|
last_activity=existing.last_activity,
|
|
has_pending_interrupt=True,
|
|
)
|
|
self._sessions = {**self._sessions, thread_id: new_state}
|
|
return new_state
|
|
|
|
def resolve_interrupt(self, thread_id: str) -> SessionState:
|
|
"""Remove interrupt extension and reset activity timer."""
|
|
new_state = SessionState(
|
|
thread_id=thread_id,
|
|
last_activity=time.time(),
|
|
has_pending_interrupt=False,
|
|
)
|
|
self._sessions = {**self._sessions, thread_id: new_state}
|
|
return new_state
|
|
|
|
def get_state(self, thread_id: str) -> SessionState | None:
|
|
return self._sessions.get(thread_id)
|
|
|
|
def remove(self, thread_id: str) -> None:
|
|
self._sessions = {k: v for k, v in self._sessions.items() if k != thread_id}
|