diff --git a/src/agent/__init__.py b/src/agent/__init__.py
index e69de29..ff3ec8c 100644
--- a/src/agent/__init__.py
+++ b/src/agent/__init__.py
@@ -0,0 +1,3 @@
+from src.agent.service import AgentService, get_agent_service
+
+__all__ = ["AgentService", "get_agent_service"]
diff --git a/src/agent/base.py b/src/agent/base.py
index c78f76f..f635ba8 100644
--- a/src/agent/base.py
+++ b/src/agent/base.py
@@ -1,26 +1,19 @@
 import os
 from deepagents import create_deep_agent
 from langchain_openai import ChatOpenAI
+from langgraph.checkpoint.memory import MemorySaver
 
 
 def create_agent():
-    api_url = os.environ.get("PROVIDER_URL")
-    api_key = os.environ.get("PROVIDER_API_KEY")
-    model_name = os.environ.get("PROVIDER_MODEL")
-
-    if None in (api_url, api_key, model_name):
-        raise RuntimeError("PROVIDER_URL, PROVIDER_API_KEY or PROVIDER_MODEL_NAME is not configured")
-
     model = ChatOpenAI(
-        model=model_name,
-        base_url=api_url,
-        api_key=api_key,
+        model=os.environ["PROVIDER_MODEL"],
+        base_url=os.environ["PROVIDER_URL"],
+        api_key=os.environ["PROVIDER_API_KEY"],
     )
 
     return create_deep_agent(
         model=model,
         system_prompt="You are a helpful assistant.",
+        checkpointer=MemorySaver(),
     )
 
-
-agent = create_agent()
diff --git a/src/agent/service.py b/src/agent/service.py
new file mode 100644
index 0000000..e0d2cc3
--- /dev/null
+++ b/src/agent/service.py
@@ -0,0 +1,34 @@
+from typing import AsyncIterator
+
+from src.agent.base import create_agent
+
+
+class AgentService:
+    _instance = None
+
+    def __new__(cls):
+        if cls._instance is None:
+            cls._instance = super().__new__(cls)
+            cls._instance._agent = create_agent()
+            cls._instance._thread_id = "default"
+        return cls._instance
+
+    async def astream(self, text: str) -> AsyncIterator[str]:
+        config = {"configurable": {"thread_id": self._thread_id}}
+
+        async for event in self._agent.astream(
+            {"messages": [{"role": "user", "content": text}]},
+            config=config,
+        ):
+            messages = event.get("messages") or event.get("model", {}).get(
+                "messages", []
+            )
+            if messages:
+                last_msg = messages[-1]
+                content = getattr(last_msg, "content", None)
+                if isinstance(content, str) and content.strip():
+                    yield content
+
+
+def get_agent_service() -> AgentService:
+    return AgentService()
diff --git a/src/api/external.py b/src/api/external.py
index 8c2579d..219d5f7 100644
--- a/src/api/external.py
+++ b/src/api/external.py
@@ -1,4 +1,4 @@
-from fastapi import APIRouter, WebSocket, WebSocketDisconnect
+from fastapi import APIRouter, WebSocket, WebSocketDisconnect, Depends
 
 from lambda_agent_api.server import (
     MsgStatus,
@@ -8,14 +8,17 @@ from lambda_agent_api.server import (
 )
 from lambda_agent_api.client import ClientMessage, MsgUserMessage
 
-from src.agent.base import agent
+from src.agent import get_agent_service, AgentService
 
 
 router = APIRouter()
 
 
 @router.websocket("/agent_ws/")
-async def websocket_endpoint(ws: WebSocket):
+async def websocket_endpoint(
+    ws: WebSocket,
+    agent_service: AgentService = Depends(get_agent_service),
+):
     await ws.accept()
     await ws.send_text(MsgStatus().model_dump_json())
 
@@ -23,7 +26,7 @@ async def websocket_endpoint(ws: WebSocket):
         while True:
             raw = await ws.receive_text()
             msg = ClientMessage.validate_json(raw)
-            await process_message(ws, msg)
+            await process_message(ws, msg, agent_service)
 
     except WebSocketDisconnect:
         pass
@@ -33,23 +36,9 @@ async def websocket_endpoint(ws: WebSocket):
         )
 
 
-async def process_message(
-    ws: WebSocket, msg
-):  # msg должно быть ClientMessage (аннотация не работает из-за TypeAdapter)
+async def process_message(ws: WebSocket, msg, agent_service: AgentService):
     match msg:
         case MsgUserMessage():
-            await handle_user_message(ws, msg.text)
-
-
-async def handle_user_message(ws: WebSocket, text: str):
-    tokens_used = 0
-
-    async for event in agent.astream({"messages": [{"role": "user", "content": text}]}):
-        messages = event.get("messages") or event.get("model", {}).get("messages", [])
-        if messages:
-            last_msg = messages[-1]
-            content = getattr(last_msg, "content", None)
-            if isinstance(content, str) and content.strip():
-                await ws.send_text(MsgEventTextChunk(text=content.strip()).model_dump_json())
-
-    await ws.send_text(MsgEventEnd(tokens_used=tokens_used).model_dump_json())
+            async for chunk in agent_service.astream(msg.text):
+                await ws.send_text(MsgEventTextChunk(text=chunk).model_dump_json())
+            await ws.send_text(MsgEventEnd(tokens_used=0).model_dump_json())
diff --git a/src/main.py b/src/main.py
index ade53dc..c11618a 100644
--- a/src/main.py
+++ b/src/main.py
@@ -1,8 +1,16 @@
+from contextlib import asynccontextmanager
+
 from fastapi import FastAPI
 
+from src.agent import get_agent_service
 from src.api.external import router as ws_router
 
 
-app = FastAPI()
-app.include_router(ws_router)
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    get_agent_service()
+    yield
 
+
+app = FastAPI(lifespan=lifespan)
+app.include_router(ws_router)