diff --git a/backend/package/yuxi/services/agent_run_service.py b/backend/package/yuxi/services/agent_run_service.py
index 3b66bde8..88076999 100644
--- a/backend/package/yuxi/services/agent_run_service.py
+++ b/backend/package/yuxi/services/agent_run_service.py
@@ -12,6 +12,7 @@ from fastapi import HTTPException
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.ext.asyncio import AsyncSession
 from yuxi.agents.buildin import agent_manager
+from yuxi.repositories.agent_config_repository import AgentConfigRepository
 from yuxi.repositories.agent_run_repository import TERMINAL_RUN_STATUSES, AgentRunRepository
 from yuxi.repositories.conversation_repository import ConversationRepository
 from yuxi.services.run_queue_service import (
@@ -51,9 +52,10 @@ def _format_sse(data: dict, event: str | None = None) -> str:
 
 async def create_agent_run_view(
     *,
-    agent_id: str,
     query: str,
-    config: dict,
+    agent_config_id: int,
+    thread_id: str,
+    meta: dict,
     image_content: str | None,
     current_user_id: str,
     db: AsyncSession,
@@ -61,19 +63,28 @@ async def create_agent_run_view(
     if not query:
         raise HTTPException(status_code=422, detail="query 不能为空")
 
+    if not thread_id:
+        raise HTTPException(status_code=422, detail="thread_id 不能为空")
+
+    config_repo = AgentConfigRepository(db)
+    config_item = await config_repo.get_by_id(config_id=int(agent_config_id))
+    if config_item is None:
+        raise HTTPException(status_code=404, detail="配置不存在")
+
+    agent_id = config_item.agent_id
     if not agent_manager.get_agent(agent_id):
         raise HTTPException(status_code=404, detail=f"智能体 {agent_id} 不存在")
 
-    thread_id = (config or {}).get("thread_id")
-    if not thread_id:
-        raise HTTPException(status_code=422, detail="config.thread_id 不能为空")
-
     conv_repo = ConversationRepository(db)
     conversation = await conv_repo.get_conversation_by_thread_id(thread_id)
     if not conversation or conversation.user_id != str(current_user_id) or conversation.status == "deleted":
         raise HTTPException(status_code=404, detail="对话线程不存在")
 
-    request_id = str((config or {}).get("request_id") or uuid.uuid4())
+    request_id = str((meta or {}).get("request_id") or uuid.uuid4())
+    config = {
+        "thread_id": thread_id,
+        "agent_config_id": int(agent_config_id),
+    }
     run_repo = AgentRunRepository(db)
     existing = await run_repo.get_run_by_request_id(request_id)
     if existing and existing.user_id == str(current_user_id):
diff --git a/backend/package/yuxi/services/chat_service.py b/backend/package/yuxi/services/chat_service.py
index fcc868fa..9e9b8675 100644
--- a/backend/package/yuxi/services/chat_service.py
+++ b/backend/package/yuxi/services/chat_service.py
@@ -298,6 +298,35 @@ def _ensure_full_msg(full_msg: AIMessage | None, accumulated_content: list[str])
     return full_msg
 
 
+def _extract_ai_message(messages: list[Any] | None) -> AIMessage | None:
+    """从消息列表中提取最后一条 AIMessage。"""
+    if not isinstance(messages, list):
+        return None
+
+    for msg in reversed(messages):
+        if isinstance(msg, AIMessage):
+            return msg
+
+        msg_dict = msg.model_dump() if hasattr(msg, "model_dump") else {}
+        if msg_dict.get("type") == "ai":
+            content = msg_dict.get("content", "")
+            return msg if hasattr(msg, "content") else AIMessage(content=content)
+
+    return None
+
+
+async def get_agent_config_by_id(db, user: User, agent_config_id: int):
+    """按配置 ID 解析 AgentConfig 记录。"""
+    department_id = user.department_id
+
+    agent_config_repo = AgentConfigRepository(db)
+    config_item = await agent_config_repo.get_by_id(config_id=int(agent_config_id))
+    if config_item is None or config_item.department_id != department_id:
+        raise ValueError("配置不存在")
+
+    return config_item
+
+
 async def _resolve_agent_config(db, agent_id: str, user: User, agent_config_id):
     """解析 agent_config，返回 agent_config"""
     department_id = user.department_id
@@ -305,8 +334,8 @@ async def _resolve_agent_config(db, agent_id: str, user: User, agent_config_id):
     agent_config_repo = AgentConfigRepository(db)
     config_item = None
     if agent_config_id is not None:
-        config_item = await agent_config_repo.get_by_id(config_id=int(agent_config_id))
-        if config_item is not None and (config_item.department_id != department_id or config_item.agent_id != agent_id):
+        config_item = await get_agent_config_by_id(db, user, int(agent_config_id))
+        if config_item.agent_id != agent_id:
             config_item = None
 
     if config_item is None:
@@ -344,9 +373,9 @@ async def check_and_handle_interrupts(
 
 async def agent_chat(
     *,
-    agent_id: str,
     query: str,
-    config: dict,
+    agent_config_id: int,
+    thread_id: str | None,
     meta: dict,
     image_content: str | None,
     current_user,
@@ -367,13 +396,6 @@ async def agent_chat(
         human_message = HumanMessage(content=query)
         message_type = "text"
 
-    init_msg = {"role": "user", "content": query, "type": "human"}
-    if image_content:
-        init_msg["message_type"] = "multimodal_image"
-        init_msg["image_content"] = image_content
-    else:
-        init_msg["message_type"] = "text"
-
     if conf.enable_content_guard and await content_guard.check(query):
         return {
             "status": "error",
@@ -382,6 +404,42 @@ async def agent_chat(
             "request_id": meta.get("request_id"),
         }
 
+    if not current_user.department_id:
+        return {
+            "status": "error",
+            "error_type": "invalid_config",
+            "error_message": "当前用户未绑定部门",
+            "request_id": meta.get("request_id"),
+        }
+
+    user_id = str(current_user.id)
+    meta = dict(meta or {})
+    if "request_id" not in meta or not meta.get("request_id"):
+        logger.warning("请求缺少 request_id，已自动生成一个新的 request_id")
+        meta["request_id"] = str(uuid.uuid4())
+
+    try:
+        config_item = await get_agent_config_by_id(db, current_user, agent_config_id)
+    except ValueError as e:
+        return {
+            "status": "error",
+            "error_type": "invalid_config",
+            "error_message": str(e),
+            "request_id": meta.get("request_id"),
+        }
+
+    agent_id = config_item.agent_id
+    meta.update(
+        {
+            "query": query,
+            "agent_id": agent_id,
+            "server_model_name": agent_id,
+            "thread_id": thread_id,
+            "user_id": current_user.id,
+            "has_image": bool(image_content),
+        }
+    )
+
     try:
         agent = agent_manager.get_agent(agent_id)
     except Exception as e:
@@ -394,20 +452,9 @@ async def agent_chat(
         }
 
     messages = [human_message]
+    agent_config = (config_item.config_json or {}).get("context", {})
 
-    user_id = str(current_user.id)
-    agent_config_id = config.get("agent_config_id")
-    try:
-        agent_config = await _resolve_agent_config(db, agent_id, current_user, agent_config_id)
-    except ValueError as e:
-        return {
-            "status": "error",
-            "error_type": "invalid_config",
-            "error_message": str(e),
-            "request_id": meta.get("request_id"),
-        }
-
-    if not (thread_id := config.get("thread_id")):
+    if not thread_id:
         thread_id = str(uuid.uuid4())
         logger.warning(f"No thread_id provided, generated new thread_id: {thread_id}")
 
@@ -429,20 +476,18 @@ async def agent_chat(
             logger.error(f"Error saving user message: {e}")
 
         langgraph_config = {"configurable": {"thread_id": thread_id, "user_id": user_id}}
+        invoke_result = await agent.invoke_messages(messages, input_context=input_context)
+        full_msg = _extract_ai_message(invoke_result.get("messages") if isinstance(invoke_result, dict) else None)
 
-        full_msg = None
-        accumulated_content: list[str] = []
+        if full_msg is None:
+            try:
+                graph = await agent.get_graph()
+                state = await graph.aget_state(langgraph_config)
+                full_msg = _extract_ai_message(getattr(state, "values", {}).get("messages", [])) if state else None
+            except Exception:
+                full_msg = None
 
-        async for msg, metadata in agent.stream_messages(messages, input_context=input_context):
-            if isinstance(msg, AIMessageChunk):
-                accumulated_content.append(msg.content)
-            else:
-                msg_dict = msg.model_dump() if hasattr(msg, "model_dump") else {}
-                if msg_dict.get("type") == "ai":
-                    full_msg = msg
-
-        full_msg = _ensure_full_msg(full_msg, accumulated_content)
-        full_content = "".join(accumulated_content) if accumulated_content else (full_msg.content if full_msg else "")
+        full_content = full_msg.content if full_msg else ""
 
         if conf.enable_content_guard and await content_guard.check(full_content):
             await save_partial_message(conv_repo, thread_id, full_msg, "content_guard_blocked")
@@ -488,9 +533,9 @@ async def agent_chat(
 
 async def stream_agent_chat(
     *,
-    agent_id: str,
     query: str,
-    config: dict,
+    agent_config_id: int,
+    thread_id: str | None,
     meta: dict,
     image_content: str | None,
     current_user,
@@ -533,6 +578,34 @@ async def stream_agent_chat(
         )
         return
 
+    if not current_user.department_id:
+        yield make_chunk(status="error", error_type="invalid_config", error_message="当前用户未绑定部门", meta=meta)
+        return
+
+    meta = dict(meta or {})
+    if "request_id" not in meta or not meta.get("request_id"):
+        logger.warning("请求缺少 request_id，已自动生成一个新的 request_id")
+        meta["request_id"] = str(uuid.uuid4())
+
+    user_id = str(current_user.id)
+    try:
+        config_item = await get_agent_config_by_id(db, current_user, agent_config_id)
+    except ValueError as e:
+        yield make_chunk(status="error", error_type="invalid_config", error_message=str(e), meta=meta)
+        return
+
+    agent_id = config_item.agent_id
+    meta.update(
+        {
+            "query": query,
+            "agent_id": agent_id,
+            "server_model_name": agent_id,
+            "thread_id": thread_id,
+            "user_id": current_user.id,
+            "has_image": bool(image_content),
+        }
+    )
+
     try:
         agent = agent_manager.get_agent(agent_id)
     except Exception as e:
@@ -546,16 +619,9 @@ async def stream_agent_chat(
         return
 
     messages = [human_message]
+    agent_config = (config_item.config_json or {}).get("context", {})
 
-    user_id = str(current_user.id)
-    agent_config_id = config.get("agent_config_id")
-    try:
-        agent_config = await _resolve_agent_config(db, agent_id, current_user, agent_config_id)
-    except ValueError as e:
-        yield make_chunk(status="error", error_type="invalid_config", error_message=str(e), meta=meta)
-        return
-
-    if not (thread_id := config.get("thread_id")):
+    if not thread_id:
         thread_id = str(uuid.uuid4())
         logger.warning(f"No thread_id provided, generated new thread_id: {thread_id}")
 
diff --git a/backend/package/yuxi/services/run_worker.py b/backend/package/yuxi/services/run_worker.py
index 5a5fa05e..238a9347 100644
--- a/backend/package/yuxi/services/run_worker.py
+++ b/backend/package/yuxi/services/run_worker.py
@@ -235,9 +235,9 @@ async def process_agent_run(ctx, run_id: str):
     try:
         async with pg_manager.get_async_session_context() as db:
             stream = stream_agent_chat(
-                agent_id=agent_id,
                 query=query,
-                config=config,
+                agent_config_id=config.get("agent_config_id"),
+                thread_id=config.get("thread_id"),
                 meta=meta,
                 image_content=image_content,
                 current_user=user,
diff --git a/backend/server/routers/chat_router.py b/backend/server/routers/chat_router.py
index 213a9fe6..42d894f1 100644
--- a/backend/server/routers/chat_router.py
+++ b/backend/server/routers/chat_router.py
@@ -14,7 +14,7 @@ from server.utils.auth_middleware import get_db, get_required_user
 from yuxi import config as conf
 from yuxi.agents.buildin import agent_manager
 from yuxi.models import select_model
-from yuxi.services.chat_service import get_agent_state_view, stream_agent_chat, stream_agent_resume, agent_chat
+from yuxi.services.chat_service import agent_chat, get_agent_state_view, stream_agent_chat, stream_agent_resume
 from yuxi.services.agent_run_service import (
     cancel_agent_run_view,
     create_agent_run_view,
@@ -43,6 +43,8 @@ from yuxi.utils.logging_config import logger
 from yuxi.utils.image_processor import process_uploaded_image
 
 
+# TODO：当前文件的功能过于庞杂，路由标签混乱
+
 # 图片上传响应模型
 class ImageUploadResponse(BaseModel):
     success: bool
@@ -76,9 +78,19 @@ class AgentConfigUpdate(BaseModel):
 
 
 class AgentRunCreate(BaseModel):
-    query: str
-    config: dict = Field(default_factory=dict)
-    image_content: str | None = None
+    query: str = Field(..., description="用户输入的问题")
+    agent_config_id: int = Field(..., description="智能体配置 ID，后端将据此解析 agent_id 和运行时 context")
+    thread_id: str = Field(..., description="会话线程 ID")
+    meta: dict = Field(default_factory=dict, description="可选，请求追踪信息，例如 request_id")
+    image_content: str | None = Field(None, description="可选，base64 图片内容")
+
+
+class AgentChatRequest(BaseModel):
+    query: str = Field(..., description="用户输入的问题")
+    agent_config_id: int = Field(..., description="智能体配置 ID，后端将据此解析 agent_id 和运行时 context")
+    thread_id: str | None = Field(None, description="可选，会话线程 ID；不传则自动创建")
+    meta: dict = Field(default_factory=dict, description="可选，请求追踪信息，例如 request_id")
+    image_content: str | None = Field(None, description="可选，base64 图片内容")
 
 
 chat = APIRouter(prefix="/chat", tags=["chat"])
@@ -218,7 +230,6 @@ async def list_agent_configs(
     if not items:
         await repo.get_or_create_default(
             department_id=current_user.department_id,
-            agent_id=agent_id,
             created_by=str(current_user.id),
         )
         items = await repo.list_by_department_agent(department_id=current_user.department_id, agent_id=agent_id)
@@ -275,7 +286,6 @@ async def create_agent_config_profile(
     repo = AgentConfigRepository(db)
     item = await repo.create(
         department_id=current_user.department_id,
-        agent_id=agent_id,
         name=payload.name,
         description=payload.description,
         icon=payload.icon,
@@ -367,44 +377,28 @@ async def delete_agent_config_profile(
     return {"success": True}
 
 
-@chat.post("/agent/{agent_id}")
+@chat.post("/agent")
 async def chat_agent(
-    agent_id: str,
-    query: str = Body(...),
-    config: dict = Body({}),
-    meta: dict = Body({}),
-    image_content: str | None = Body(None),
+    payload: AgentChatRequest,
     current_user: User = Depends(get_required_user),
     db: AsyncSession = Depends(get_db),
 ):
     """使用特定智能体进行对话（需要登录）"""
-    logger.info(f"agent_id: {agent_id}, query: {query}, config: {config}, meta: {meta}")
-    logger.info(f"image_content present: {image_content is not None}")
-    if image_content:
-        logger.info(f"image_content length: {len(image_content)}")
-        logger.info(f"image_content preview: {image_content[:50]}...")
+    logger.info(f"query: {payload.query}, agent_config_id: {payload.agent_config_id}, meta: {payload.meta}")
 
-    # 确保 request_id 存在
-    if "request_id" not in meta or not meta.get("request_id"):
-        meta["request_id"] = str(uuid.uuid4())
+    # 查看图片内容
+    logger.info(f"image_content present: {payload.image_content is not None}")
+    if payload.image_content:
+        logger.info(f"image_content length: {len(payload.image_content)}")
+        logger.info(f"image_content preview: {payload.image_content[:50]}...")
 
-    meta.update(
-        {
-            "query": query,
-            "agent_id": agent_id,
-            "server_model_name": config.get("model", agent_id),
-            "thread_id": config.get("thread_id"),
-            "user_id": current_user.id,
-            "has_image": bool(image_content),
-        }
-    )
     return StreamingResponse(
         stream_agent_chat(
-            agent_id=agent_id,
-            query=query,
-            config=config,
-            meta=meta,
-            image_content=image_content,
+            query=payload.query,
+            agent_config_id=payload.agent_config_id,
+            thread_id=payload.thread_id,
+            meta=dict(payload.meta or {}),
+            image_content=payload.image_content,
             current_user=current_user,
             db=db,
         ),
@@ -412,60 +406,41 @@ async def chat_agent(
     )
 
 
-@chat.post("/agent/{agent_id}/sync")
+@chat.post("/agent/sync")
 async def chat_agent_sync(
-    agent_id: str,
-    query: str = Body(...),
-    config: dict = Body({}),
-    meta: dict = Body({}),
-    image_content: str | None = Body(None),
+    payload: AgentChatRequest,
     current_user: User = Depends(get_required_user),
     db: AsyncSession = Depends(get_db),
 ):
     """使用特定智能体进行非流式对话（需要登录）"""
-    logger.info(f"[sync] agent_id: {agent_id}, query: {query}, config: {config}, meta: {meta}")
-    logger.info(f"[sync] image_content present: {image_content is not None}")
-    if image_content:
-        logger.info(f"[sync] image_content length: {len(image_content)}")
-
-    # 确保 request_id 存在
-    if "request_id" not in meta or not meta.get("request_id"):
-        meta["request_id"] = str(uuid.uuid4())
-
-    meta.update(
-        {
-            "query": query,
-            "agent_id": agent_id,
-            "server_model_name": config.get("model", agent_id),
-            "thread_id": config.get("thread_id"),
-            "user_id": current_user.id,
-            "has_image": bool(image_content),
-        }
-    )
+    logger.info(f"[sync] query: {payload.query}, agent_config_id: {payload.agent_config_id}, meta: {payload.meta}")
+    logger.info(f"[sync] image_content present: {payload.image_content is not None}")
+    if payload.image_content:
+        logger.info(f"[sync] image_content length: {len(payload.image_content)}")
 
     return await agent_chat(
-        agent_id=agent_id,
-        query=query,
-        config=config,
-        meta=meta,
-        image_content=image_content,
+        query=payload.query,
+        agent_config_id=payload.agent_config_id,
+        thread_id=payload.thread_id,
+        meta=dict(payload.meta or {}),
+        image_content=payload.image_content,
         current_user=current_user,
         db=db,
     )
 
 
-@chat.post("/agent/{agent_id}/runs")
+@chat.post("/runs")
 async def create_agent_run(
-    agent_id: str,
     payload: AgentRunCreate,
     current_user: User = Depends(get_required_user),
     db: AsyncSession = Depends(get_db),
 ):
     """创建异步 run 任务并入队（需要登录）"""
     return await create_agent_run_view(
-        agent_id=agent_id,
         query=payload.query,
-        config=payload.config or {},
+        agent_config_id=payload.agent_config_id,
+        thread_id=payload.thread_id,
+        meta=dict(payload.meta or {}),
         image_content=payload.image_content,
         current_user_id=str(current_user.id),
         db=db,
@@ -627,7 +602,6 @@ async def resume_agent_chat(
         meta["request_id"] = str(uuid.uuid4())
     return StreamingResponse(
         stream_agent_resume(
-            agent_id=agent_id,
             thread_id=thread_id,
             resume_input=resume_input,
             meta=meta,
diff --git a/backend/test/api/test_agent_bubble_sort_e2e.py b/backend/test/api/test_agent_bubble_sort_e2e.py
index 37b150ed..8dfaf3a6 100644
--- a/backend/test/api/test_agent_bubble_sort_e2e.py
+++ b/backend/test/api/test_agent_bubble_sort_e2e.py
@@ -49,6 +49,7 @@ class AgentBubbleSortE2ETester:
         self.client = httpx.AsyncClient(base_url=API_BASE_URL, timeout=TIMEOUT, follow_redirects=True)
         self.headers: dict[str, str] | None = None
         self.agent_id: str | None = None
+        self.agent_config_id: int | None = None
         self.thread_id: str | None = None
 
     async def close(self):
@@ -98,14 +99,29 @@ class AgentBubbleSortE2ETester:
         if not self.thread_id:
             raise RuntimeError(f"thread id missing: {payload}")
 
+    async def pick_agent_config(self) -> None:
+        assert self.headers and self.agent_id
+        response = await self.client.get(f"/api/chat/agent/{self.agent_id}/configs", headers=self.headers)
+        if response.status_code != 200:
+            raise RuntimeError(f"list configs failed: {response.status_code} {response.text}")
+        configs = response.json().get("configs") or []
+        if not configs:
+            raise RuntimeError("no available agent configs")
+        config_id = configs[0].get("id")
+        if not config_id:
+            raise RuntimeError(f"config id missing: {response.text}")
+        self.agent_config_id = int(config_id)
+
     async def create_run(self, query: str) -> str:
-        assert self.headers and self.agent_id and self.thread_id
+        assert self.headers and self.agent_config_id and self.thread_id
         request_id = f"agent-bubble-sort-{uuid.uuid4()}"
         response = await self.client.post(
-            f"/api/chat/agent/{self.agent_id}/runs",
+            "/api/chat/runs",
             json={
                 "query": query,
-                "config": {"thread_id": self.thread_id, "request_id": request_id},
+                "agent_config_id": self.agent_config_id,
+                "thread_id": self.thread_id,
+                "meta": {"request_id": request_id},
             },
             headers=self.headers,
         )
@@ -166,6 +182,7 @@ class AgentBubbleSortE2ETester:
     async def run_case(self) -> None:
         await self.login()
         await self.pick_agent()
+        await self.pick_agent_config()
         await self.create_thread()
 
         query = (
diff --git a/backend/test/api/test_apikey_router.py b/backend/test/api/test_apikey_router.py
index 41964a42..f7064a79 100644
--- a/backend/test/api/test_apikey_router.py
+++ b/backend/test/api/test_apikey_router.py
@@ -9,6 +9,26 @@ import pytest
 pytestmark = [pytest.mark.asyncio, pytest.mark.integration]
 
 
+async def _get_default_agent_config_id(test_client, headers):
+    agent_response = await test_client.get("/api/chat/default_agent", headers=headers)
+    assert agent_response.status_code == 200
+    agent_id = agent_response.json().get("default_agent_id")
+    if not agent_id:
+        pytest.skip("No default agent configured")
+
+    configs_response = await test_client.get(f"/api/chat/agent/{agent_id}/configs", headers=headers)
+    assert configs_response.status_code == 200, configs_response.text
+    configs = configs_response.json().get("configs", [])
+    if not configs:
+        pytest.skip("No configs found for default agent")
+
+    config_id = configs[0].get("id")
+    if not config_id:
+        pytest.skip("Agent config payload missing id field.")
+
+    return agent_id, config_id
+
+
 async def test_list_api_keys_requires_auth(test_client):
     """List API keys should require authentication."""
     response = await test_client.get("/api/apikey/")
@@ -46,9 +66,7 @@ async def test_create_api_key(test_client, admin_headers):
 async def test_get_api_key(test_client, admin_headers):
     """Admin should be able to get a single API key."""
     # First create a key
-    create_response = await test_client.post(
-        "/api/apikey/", json={"name": "Get Test"}, headers=admin_headers
-    )
+    create_response = await test_client.post("/api/apikey/", json={"name": "Get Test"}, headers=admin_headers)
     assert create_response.status_code == 200
     created = create_response.json()["api_key"]
 
@@ -63,9 +81,7 @@ async def test_get_api_key(test_client, admin_headers):
 async def test_update_api_key(test_client, admin_headers):
     """Admin should be able to update an API key."""
     # Create a key
-    create_response = await test_client.post(
-        "/api/apikey/", json={"name": "Update Test"}, headers=admin_headers
-    )
+    create_response = await test_client.post("/api/apikey/", json={"name": "Update Test"}, headers=admin_headers)
     assert create_response.status_code == 200
     created = create_response.json()["api_key"]
 
@@ -84,9 +100,7 @@ async def test_update_api_key(test_client, admin_headers):
 async def test_delete_api_key(test_client, admin_headers):
     """Admin should be able to delete an API key."""
     # Create a key
-    create_response = await test_client.post(
-        "/api/apikey/", json={"name": "Delete Test"}, headers=admin_headers
-    )
+    create_response = await test_client.post("/api/apikey/", json={"name": "Delete Test"}, headers=admin_headers)
     assert create_response.status_code == 200
     created = create_response.json()["api_key"]
 
@@ -103,9 +117,7 @@ async def test_delete_api_key(test_client, admin_headers):
 async def test_regenerate_api_key(test_client, admin_headers):
     """Admin should be able to regenerate an API key."""
     # Create a key
-    create_response = await test_client.post(
-        "/api/apikey/", json={"name": "Regenerate Test"}, headers=admin_headers
-    )
+    create_response = await test_client.post("/api/apikey/", json={"name": "Regenerate Test"}, headers=admin_headers)
     assert create_response.status_code == 200
     original_secret = create_response.json()["secret"]
     created = create_response.json()["api_key"]
@@ -122,26 +134,19 @@ async def test_regenerate_api_key(test_client, admin_headers):
 async def test_api_key_auth_chat_endpoint(test_client, admin_headers):
     """Test that API Key can be used to authenticate to chat endpoint via Bearer token."""
     # Create an API key
-    create_response = await test_client.post(
-        "/api/apikey/", json={"name": "Chat Auth Test"}, headers=admin_headers
-    )
+    create_response = await test_client.post("/api/apikey/", json={"name": "Chat Auth Test"}, headers=admin_headers)
     assert create_response.status_code == 200
     api_key_secret = create_response.json()["secret"]
     created = create_response.json()["api_key"]
 
     try:
-        # Get default agent
-        agent_response = await test_client.get("/api/chat/default_agent", headers=admin_headers)
-        assert agent_response.status_code == 200
-        agent_id = agent_response.json().get("default_agent_id")
-        if not agent_id:
-            pytest.skip("No default agent configured")
+        _, agent_config_id = await _get_default_agent_config_id(test_client, admin_headers)
 
         # Call chat endpoint with API Key using Bearer format (streaming response)
         async with test_client.stream(
             "POST",
-            f"/api/chat/agent/{agent_id}",
-            json={"query": "Hello"},
+            "/api/chat/agent",
+            json={"query": "Hello", "agent_config_id": agent_config_id},
             headers={"Authorization": f"Bearer {api_key_secret}"},
         ) as response:
             assert response.status_code == 200, response.text
@@ -155,8 +160,8 @@ async def test_api_key_auth_requires_valid_key(test_client):
     """Test that invalid API Key is rejected."""
     # Call chat endpoint with invalid API Key
     response = await test_client.post(
-        "/api/chat/agent/ChatbotAgent",
-        json={"query": "Hello"},
+        "/api/chat/agent",
+        json={"query": "Hello", "agent_config_id": 1},
         headers={"Authorization": "Bearer yxkey_invalid_key_that_does_not_exist"},
     )
     assert response.status_code == 401, response.text
@@ -165,9 +170,7 @@ async def test_api_key_auth_requires_valid_key(test_client):
 async def test_api_key_auth_requires_bearer_prefix(test_client, admin_headers):
     """Test that API Key must be prefixed with 'Bearer '."""
     # Create an API key
-    admin_response = await test_client.post(
-        "/api/apikey/", json={"name": "Prefix Test"}, headers=admin_headers
-    )
+    admin_response = await test_client.post("/api/apikey/", json={"name": "Prefix Test"}, headers=admin_headers)
     assert admin_response.status_code == 200
     api_key_secret = admin_response.json()["secret"]
     created = admin_response.json()["api_key"]
@@ -175,8 +178,8 @@ async def test_api_key_auth_requires_bearer_prefix(test_client, admin_headers):
     try:
         # Call without Bearer prefix should fail
         response = await test_client.post(
-            "/api/chat/agent/ChatbotAgent",
-            json={"query": "Hello"},
+            "/api/chat/agent",
+            json={"query": "Hello", "agent_config_id": 1},
             headers={"Authorization": api_key_secret},  # Missing "Bearer " prefix
         )
         assert response.status_code == 401, response.text
@@ -187,18 +190,13 @@ async def test_api_key_auth_requires_bearer_prefix(test_client, admin_headers):
 
 async def test_jwt_still_works_after_apikey_auth(test_client, admin_headers):
     """Test that JWT Bearer tokens still work after API Key changes."""
-    # Get default agent
-    agent_response = await test_client.get("/api/chat/default_agent", headers=admin_headers)
-    assert agent_response.status_code == 200
-    agent_id = agent_response.json().get("default_agent_id")
-    if not agent_id:
-        pytest.skip("No default agent configured")
+    _, agent_config_id = await _get_default_agent_config_id(test_client, admin_headers)
 
     # Call chat with JWT Bearer token (admin_headers) - streaming response
     async with test_client.stream(
         "POST",
-        f"/api/chat/agent/{agent_id}",
-        json={"query": "Hello"},
+        "/api/chat/agent",
+        json={"query": "Hello", "agent_config_id": agent_config_id},
         headers=admin_headers,
     ) as response:
         assert response.status_code == 200, response.text
@@ -208,9 +206,7 @@ async def test_jwt_still_works_after_apikey_auth(test_client, admin_headers):
 async def test_api_key_auto_binds_to_current_user(test_client, admin_headers):
     """Test that API Key created without user_id is auto-bound to creator."""
     # Create API key as admin
-    create_response = await test_client.post(
-        "/api/apikey/", json={"name": "Auto Bind Test"}, headers=admin_headers
-    )
+    create_response = await test_client.post("/api/apikey/", json={"name": "Auto Bind Test"}, headers=admin_headers)
     assert create_response.status_code == 200
     created = create_response.json()["api_key"]
 
@@ -220,15 +216,14 @@ async def test_api_key_auto_binds_to_current_user(test_client, admin_headers):
 
         # Verify the key can be used for auth
         api_key_secret = create_response.json()["secret"]
+        _, agent_config_id = await _get_default_agent_config_id(test_client, admin_headers)
         async with test_client.stream(
             "POST",
-            "/api/chat/agent/ChatbotAgent",
-            json={"query": "Hello"},
+            "/api/chat/agent",
+            json={"query": "Hello", "agent_config_id": agent_config_id},
             headers={"Authorization": f"Bearer {api_key_secret}"},
         ) as response:
             assert response.status_code == 200, response.text
     finally:
         # Cleanup: delete the test API key
         await test_client.delete(f"/api/apikey/{created['id']}", headers=admin_headers)
-
-
diff --git a/backend/test/api/test_attachment_and_agent_state.py b/backend/test/api/test_attachment_and_agent_state.py
index 33169765..3af434e8 100644
--- a/backend/test/api/test_attachment_and_agent_state.py
+++ b/backend/test/api/test_attachment_and_agent_state.py
@@ -183,6 +183,25 @@ class APITester:
             print(f"   ✗ 获取失败: {response.status_code} - {response.text}")
             return None
 
+    async def get_agent_config_id(self, agent_id: str) -> int | None:
+        """获取指定 Agent 的一个配置 ID"""
+        async with self._client() as client:
+            response = await client.get(
+                f"{self.base_url}/api/chat/agent/{agent_id}/configs",
+                headers=self.headers,
+            )
+
+        if response.status_code != 200:
+            print(f"   ✗ 获取 Agent 配置失败: {response.status_code} - {response.text}")
+            return None
+
+        configs = response.json().get("configs", [])
+        if not configs:
+            print("   ✗ 当前 Agent 没有可用配置")
+            return None
+
+        return configs[0].get("id")
+
     async def send_chat_message(self, agent_id: str, thread_id: str, query: str) -> bool:
         """发送聊天消息（流式）"""
         print(f"\n{'=' * 60}")
@@ -191,11 +210,19 @@ class APITester:
         print(f"   Query: {query}")
         print(f"   Thread ID: {thread_id}")
 
+        agent_config_id = await self.get_agent_config_id(agent_id)
+        if not agent_config_id:
+            return False
+
         async with self._client(timeout=120.0) as client:
             async with client.stream(
                 "POST",
-                f"{self.base_url}/api/chat/agent/{agent_id}",
-                json={"query": query, "config": {"thread_id": thread_id}},
+                f"{self.base_url}/api/chat/agent",
+                json={
+                    "query": query,
+                    "agent_config_id": agent_config_id,
+                    "thread_id": thread_id,
+                },
                 headers=self.headers,
             ) as response:
                 print(f"\n   响应状态: {response.status_code}")
diff --git a/backend/test/api/test_chat_agent_sync.py b/backend/test/api/test_chat_agent_sync.py
index c0aa6c1a..83b77272 100644
--- a/backend/test/api/test_chat_agent_sync.py
+++ b/backend/test/api/test_chat_agent_sync.py
@@ -9,16 +9,8 @@ import pytest
 pytestmark = [pytest.mark.asyncio, pytest.mark.integration]
 
 
-async def test_chat_agent_sync_requires_authentication(test_client):
-    """非流式端点需要认证"""
-    response = await test_client.post("/api/chat/agent/test_agent/sync", json={"query": "hello"})
-    assert response.status_code == 401
-
-
-async def test_chat_agent_sync_basic_conversation(test_client, admin_headers):
-    """测试非流式对话基本功能"""
-    # 先获取可用智能体
-    agents_response = await test_client.get("/api/chat/agent", headers=admin_headers)
+async def _get_agent_and_config_id(test_client, headers):
+    agents_response = await test_client.get("/api/chat/agent", headers=headers)
     assert agents_response.status_code == 200, agents_response.text
     agents = agents_response.json().get("agents", [])
 
@@ -29,10 +21,33 @@ async def test_chat_agent_sync_basic_conversation(test_client, admin_headers):
     if not agent_id:
         pytest.skip("Agent payload missing id field.")
 
+    configs_response = await test_client.get(f"/api/chat/agent/{agent_id}/configs", headers=headers)
+    assert configs_response.status_code == 200, configs_response.text
+    configs = configs_response.json().get("configs", [])
+    if not configs:
+        pytest.skip("No agent configs are available in the system.")
+
+    config_id = configs[0].get("id")
+    if not config_id:
+        pytest.skip("Agent config payload missing id field.")
+
+    return agent_id, config_id
+
+
+async def test_chat_agent_sync_requires_authentication(test_client):
+    """非流式端点需要认证"""
+    response = await test_client.post("/api/chat/agent/sync", json={"query": "hello", "agent_config_id": 1})
+    assert response.status_code == 401
+
+
+async def test_chat_agent_sync_basic_conversation(test_client, admin_headers):
+    """测试非流式对话基本功能"""
+    _, agent_config_id = await _get_agent_and_config_id(test_client, admin_headers)
+
     # 调用非流式端点
     response = await test_client.post(
-        f"/api/chat/agent/{agent_id}/sync",
-        json={"query": "Hello, say 'Hi' back to me"},
+        "/api/chat/agent/sync",
+        json={"query": "Hello, say 'Hi' back to me", "agent_config_id": agent_config_id},
         headers=admin_headers,
     )
 
@@ -58,26 +73,18 @@ async def test_chat_agent_sync_basic_conversation(test_client, admin_headers):
 
 async def test_chat_agent_sync_with_thread_id(test_client, admin_headers):
     """测试非流式对话指定 thread_id"""
-    # 获取可用智能体
-    agents_response = await test_client.get("/api/chat/agent", headers=admin_headers)
-    assert agents_response.status_code == 200, agents_response.text
-    agents = agents_response.json().get("agents", [])
-
-    if not agents:
-        pytest.skip("No agents are registered in the system.")
-
-    agent_id = agents[0].get("id")
-    if not agent_id:
-        pytest.skip("Agent payload missing id field.")
+    _, agent_config_id = await _get_agent_and_config_id(test_client, admin_headers)
 
     import uuid
+
     thread_id = str(uuid.uuid4())
 
     response = await test_client.post(
-        f"/api/chat/agent/{agent_id}/sync",
+        "/api/chat/agent/sync",
         json={
             "query": "Hello",
-            "config": {"thread_id": thread_id},
+            "agent_config_id": agent_config_id,
+            "thread_id": thread_id,
         },
         headers=admin_headers,
     )
@@ -87,29 +94,24 @@ async def test_chat_agent_sync_with_thread_id(test_client, admin_headers):
 
     # 验证 thread_id 是否保持一致
     if payload["status"] == "finished":
-        assert payload.get("thread_id") == thread_id, f"thread_id mismatch: expected {thread_id}, got {payload.get('thread_id')}"
+        assert payload.get("thread_id") == thread_id, (
+            f"thread_id mismatch: expected {thread_id}, got {payload.get('thread_id')}"
+        )
 
 
 async def test_chat_agent_sync_with_meta(test_client, admin_headers):
     """测试非流式对话传递 meta 参数"""
-    agents_response = await test_client.get("/api/chat/agent", headers=admin_headers)
-    assert agents_response.status_code == 200, agents_response.text
-    agents = agents_response.json().get("agents", [])
-
-    if not agents:
-        pytest.skip("No agents are registered in the system.")
-
-    agent_id = agents[0].get("id")
-    if not agent_id:
-        pytest.skip("Agent payload missing id field.")
+    _, agent_config_id = await _get_agent_and_config_id(test_client, admin_headers)
 
     import uuid
+
     request_id = str(uuid.uuid4())
 
     response = await test_client.post(
-        f"/api/chat/agent/{agent_id}/sync",
+        "/api/chat/agent/sync",
         json={
             "query": "Hello",
+            "agent_config_id": agent_config_id,
             "meta": {"request_id": request_id},
         },
         headers=admin_headers,
@@ -119,35 +121,29 @@ async def test_chat_agent_sync_with_meta(test_client, admin_headers):
     payload = response.json()
 
     # 验证 request_id 是否保持一致
-    assert payload.get("request_id") == request_id, f"request_id mismatch: expected {request_id}, got {payload.get('request_id')}"
+    assert payload.get("request_id") == request_id, (
+        f"request_id mismatch: expected {request_id}, got {payload.get('request_id')}"
+    )
 
 
 async def test_chat_agent_sync_vs_streaming_consistency(test_client, admin_headers):
     """对比测试：非流式与流式端点行为一致性"""
-    # 获取可用智能体
-    agents_response = await test_client.get("/api/chat/agent", headers=admin_headers)
-    assert agents_response.status_code == 200, agents_response.text
-    agents = agents_response.json().get("agents", [])
-
-    if not agents:
-        pytest.skip("No agents are registered in the system.")
-
-    agent_id = agents[0].get("id")
-    if not agent_id:
-        pytest.skip("Agent payload missing id field.")
+    _, agent_config_id = await _get_agent_and_config_id(test_client, admin_headers)
 
     query = "What is 1+1?"
 
     # 调用流式端点
     import uuid
+
     thread_id = str(uuid.uuid4())
     request_id = str(uuid.uuid4())
 
     streaming_response = await test_client.post(
-        f"/api/chat/agent/{agent_id}",
+        "/api/chat/agent",
         json={
             "query": query,
-            "config": {"thread_id": thread_id},
+            "agent_config_id": agent_config_id,
+            "thread_id": thread_id,
             "meta": {"request_id": request_id},
         },
         headers=admin_headers,
@@ -160,11 +156,12 @@ async def test_chat_agent_sync_vs_streaming_consistency(test_client, admin_heade
     async for line in streaming_response.aiter_lines():
         if line:
             import json as json_lib
+
             try:
                 data = json_lib.loads(line)
                 if data.get("response"):
                     streaming_content.append(data["response"])
-            except:
+            except Exception:
                 pass
 
     # 调用非流式端点
@@ -172,10 +169,11 @@ async def test_chat_agent_sync_vs_streaming_consistency(test_client, admin_heade
     request_id2 = str(uuid.uuid4())
 
     sync_response = await test_client.post(
-        f"/api/chat/agent/{agent_id}/sync",
+        "/api/chat/agent/sync",
         json={
             "query": query,
-            "config": {"thread_id": thread_id2},
+            "agent_config_id": agent_config_id,
+            "thread_id": thread_id2,
             "meta": {"request_id": request_id2},
         },
         headers=admin_headers,
diff --git a/backend/test/test_agent_run_service.py b/backend/test/test_agent_run_service.py
index 0939c4e2..419fc725 100644
--- a/backend/test/test_agent_run_service.py
+++ b/backend/test/test_agent_run_service.py
@@ -9,6 +9,14 @@ from sqlalchemy.exc import IntegrityError
 import yuxi.services.agent_run_service as agent_run_service
 
 
+class FakeConfigRepo:
+    def __init__(self, db_session):
+        self.db = db_session
+
+    async def get_by_id(self, config_id: int):
+        return SimpleNamespace(id=config_id, agent_id="ChatbotAgent", department_id=1)
+
+
 @pytest.mark.asyncio
 async def test_stream_agent_run_events_emits_error_and_close_on_db_error(monkeypatch: pytest.MonkeyPatch):
     @asynccontextmanager
@@ -134,7 +142,7 @@ async def test_create_agent_run_commits_before_enqueue(monkeypatch: pytest.Monke
 
         async def get_conversation_by_thread_id(self, thread_id: str):
             del thread_id
-            return SimpleNamespace(user_id="1", status="active")
+            return SimpleNamespace(user_id="1", status="active", department_id=1)
 
     class Queue:
         async def enqueue_job(self, job_name: str, run_id: str, _job_id: str):
@@ -148,14 +156,16 @@ async def test_create_agent_run_commits_before_enqueue(monkeypatch: pytest.Monke
         return Queue()
 
     monkeypatch.setattr(agent_run_service.agent_manager, "get_agent", lambda agent_id: object())
+    monkeypatch.setattr(agent_run_service, "AgentConfigRepository", FakeConfigRepo)
     monkeypatch.setattr(agent_run_service, "ConversationRepository", ConvRepo)
     monkeypatch.setattr(agent_run_service, "AgentRunRepository", Repo)
     monkeypatch.setattr(agent_run_service, "get_arq_pool", fake_get_arq_pool)
 
     result = await agent_run_service.create_agent_run_view(
-        agent_id="ChatbotAgent",
         query="hello",
-        config={"thread_id": "thread-1", "request_id": "req-1"},
+        agent_config_id=1,
+        thread_id="thread-1",
+        meta={"request_id": "req-1"},
         image_content=None,
         current_user_id="1",
         db=db,
@@ -217,20 +227,22 @@ async def test_create_agent_run_handles_integrity_error_with_same_user_existing(
 
         async def get_conversation_by_thread_id(self, thread_id: str):
             del thread_id
-            return SimpleNamespace(user_id="1", status="active")
+            return SimpleNamespace(user_id="1", status="active", department_id=1)
 
     async def fake_get_arq_pool():
         raise AssertionError("should not enqueue on integrity fallback")
 
     monkeypatch.setattr(agent_run_service.agent_manager, "get_agent", lambda agent_id: object())
+    monkeypatch.setattr(agent_run_service, "AgentConfigRepository", FakeConfigRepo)
     monkeypatch.setattr(agent_run_service, "ConversationRepository", ConvRepo)
     monkeypatch.setattr(agent_run_service, "AgentRunRepository", Repo)
     monkeypatch.setattr(agent_run_service, "get_arq_pool", fake_get_arq_pool)
 
     result = await agent_run_service.create_agent_run_view(
-        agent_id="ChatbotAgent",
         query="hello",
-        config={"thread_id": "thread-1", "request_id": "req-1"},
+        agent_config_id=1,
+        thread_id="thread-1",
+        meta={"request_id": "req-1"},
         image_content=None,
         current_user_id="1",
         db=db,
@@ -288,17 +300,19 @@ async def test_create_agent_run_integrity_error_returns_409_for_other_user(monke
 
         async def get_conversation_by_thread_id(self, thread_id: str):
             del thread_id
-            return SimpleNamespace(user_id="1", status="active")
+            return SimpleNamespace(user_id="1", status="active", department_id=1)
 
     monkeypatch.setattr(agent_run_service.agent_manager, "get_agent", lambda agent_id: object())
+    monkeypatch.setattr(agent_run_service, "AgentConfigRepository", FakeConfigRepo)
     monkeypatch.setattr(agent_run_service, "ConversationRepository", ConvRepo)
     monkeypatch.setattr(agent_run_service, "AgentRunRepository", Repo)
 
     with pytest.raises(agent_run_service.HTTPException) as exc:
         await agent_run_service.create_agent_run_view(
-            agent_id="ChatbotAgent",
             query="hello",
-            config={"thread_id": "thread-1", "request_id": "req-1"},
+            agent_config_id=1,
+            thread_id="thread-1",
+            meta={"request_id": "req-1"},
             image_content=None,
             current_user_id="1",
             db=db,
diff --git a/backend/test/test_chat_service_sync.py b/backend/test/test_chat_service_sync.py
new file mode 100644
index 00000000..92d3b6ac
--- /dev/null
+++ b/backend/test/test_chat_service_sync.py
@@ -0,0 +1,155 @@
+from __future__ import annotations
+
+from types import SimpleNamespace
+
+import pytest
+from langchain.messages import AIMessage, HumanMessage
+
+from yuxi.services import chat_service as svc
+
+
+class _FakeConvRepo:
+    def __init__(self, _db):
+        self.saved_messages: list[dict] = []
+
+    async def add_message_by_thread_id(
+        self,
+        *,
+        thread_id: str,
+        role: str,
+        content: str,
+        message_type: str = "text",
+        extra_metadata: dict | None = None,
+        image_content: str | None = None,
+    ):
+        self.saved_messages.append(
+            {
+                "thread_id": thread_id,
+                "role": role,
+                "content": content,
+                "message_type": message_type,
+                "extra_metadata": extra_metadata,
+                "image_content": image_content,
+            }
+        )
+        return SimpleNamespace(id=1)
+
+
+@pytest.mark.asyncio
+async def test_agent_chat_uses_invoke_messages_and_persists_langgraph_state(monkeypatch: pytest.MonkeyPatch):
+    calls: dict[str, object] = {}
+
+    class FakeGraph:
+        async def aget_state(self, config):
+            calls["state_config"] = config
+            return SimpleNamespace(values={"messages": [AIMessage(content="Hi from graph")], "todos": ["todo-1"]})
+
+    class FakeAgent:
+        async def invoke_messages(self, messages, input_context=None, **kwargs):
+            calls["invoke_messages"] = messages
+            calls["invoke_input_context"] = input_context
+            return {"messages": [messages[0], AIMessage(content="Hi from invoke")]}
+
+        async def stream_messages(self, messages, input_context=None, **kwargs):
+            raise AssertionError("stream_messages should not be used by sync chat")
+
+        async def get_graph(self):
+            return FakeGraph()
+
+    async def fake_get_agent_config_by_id(db, user, agent_config_id):
+        assert user.id == "user-1"
+        assert agent_config_id == 123
+        return SimpleNamespace(agent_id="test-agent", config_json={"context": {"temperature": 0.1}})
+
+    async def fake_save_messages_from_langgraph_state(*, agent_instance, thread_id, conv_repo, config_dict):
+        calls["saved_state"] = {
+            "agent_instance": agent_instance,
+            "thread_id": thread_id,
+            "conv_repo": conv_repo,
+            "config_dict": config_dict,
+        }
+
+    async def fake_guard_check(_content):
+        return False
+
+    monkeypatch.setattr(svc.agent_manager, "get_agent", lambda agent_id: FakeAgent())
+    monkeypatch.setattr(svc, "get_agent_config_by_id", fake_get_agent_config_by_id)
+    monkeypatch.setattr(svc, "ConversationRepository", _FakeConvRepo)
+    monkeypatch.setattr(svc, "save_messages_from_langgraph_state", fake_save_messages_from_langgraph_state)
+    monkeypatch.setattr(svc.content_guard, "check", fake_guard_check)
+
+    result = await svc.agent_chat(
+        query="hello",
+        agent_config_id=123,
+        thread_id="thread-1",
+        meta={"request_id": "req-1"},
+        image_content=None,
+        current_user=SimpleNamespace(id="user-1", department_id="dept-1"),
+        db=object(),
+    )
+
+    assert result["status"] == "finished"
+    assert result["response"] == "Hi from invoke"
+    assert result["thread_id"] == "thread-1"
+    assert result["request_id"] == "req-1"
+    assert result["agent_state"] == {"todos": ["todo-1"], "files": {}}
+
+    invoke_messages = calls["invoke_messages"]
+    assert isinstance(invoke_messages, list)
+    assert len(invoke_messages) == 1
+    assert isinstance(invoke_messages[0], HumanMessage)
+    assert invoke_messages[0].content == "hello"
+    assert calls["invoke_input_context"] == {"temperature": 0.1, "user_id": "user-1", "thread_id": "thread-1"}
+    assert calls["saved_state"]["thread_id"] == "thread-1"
+    assert calls["saved_state"]["config_dict"] == {"configurable": {"thread_id": "thread-1", "user_id": "user-1"}}
+
+
+@pytest.mark.asyncio
+async def test_agent_chat_sync_returns_finished_even_when_state_has_interrupt(monkeypatch: pytest.MonkeyPatch):
+    class FakeGraph:
+        async def aget_state(self, config):
+            return SimpleNamespace(
+                values={
+                    "messages": [AIMessage(content="Need input later")],
+                    "__interrupt__": [{"questions": [{"question": "继续吗？"}]}],
+                }
+            )
+
+    class FakeAgent:
+        async def invoke_messages(self, messages, input_context=None, **kwargs):
+            return {"messages": [messages[0], AIMessage(content="Need input later")]}
+
+        async def stream_messages(self, messages, input_context=None, **kwargs):
+            raise AssertionError("stream_messages should not be used by sync chat")
+
+        async def get_graph(self):
+            return FakeGraph()
+
+    async def fake_get_agent_config_by_id(db, user, agent_config_id):
+        return SimpleNamespace(agent_id="test-agent", config_json={"context": {}})
+
+    async def fake_save_messages_from_langgraph_state(*, agent_instance, thread_id, conv_repo, config_dict):
+        return None
+
+    async def fake_guard_check(_content):
+        return False
+
+    monkeypatch.setattr(svc.agent_manager, "get_agent", lambda agent_id: FakeAgent())
+    monkeypatch.setattr(svc, "get_agent_config_by_id", fake_get_agent_config_by_id)
+    monkeypatch.setattr(svc, "ConversationRepository", _FakeConvRepo)
+    monkeypatch.setattr(svc, "save_messages_from_langgraph_state", fake_save_messages_from_langgraph_state)
+    monkeypatch.setattr(svc.content_guard, "check", fake_guard_check)
+
+    result = await svc.agent_chat(
+        query="hello",
+        agent_config_id=456,
+        thread_id="thread-2",
+        meta={"request_id": "req-2"},
+        image_content=None,
+        current_user=SimpleNamespace(id="user-1", department_id="dept-1"),
+        db=object(),
+    )
+
+    assert result["status"] == "finished"
+    assert result["response"] == "Need input later"
+    assert result["thread_id"] == "thread-2"
diff --git a/docs/advanced/api-key-integration.md b/docs/advanced/api-key-integration.md
index 0611533d..66ac733c 100644
--- a/docs/advanced/api-key-integration.md
+++ b/docs/advanced/api-key-integration.md
@@ -14,7 +14,7 @@ API Key 是一种用于身份验证的密钥字符串，外部系统可以通过
 
 ## 接口调用方式
 
-外部系统通过 HTTP 请求调用 Yuxi 的对话接口，需要在请求头中携带 API Key。接口地址为 `POST /api/chat/agent/{agent_id}`，其中 `{agent_id}` 是目标智能体的标识符。请求头需要包含 `Authorization` 字段，值格式为 `Bearer <api_key>`，其中 `<api_key>` 是创建 API Key 时获取的完整密钥。请求体为 JSON 格式，包含 `query` 字段表示用户问题，以及可选的 `config` 和 `meta` 字段用于配置对话参数。
+外部系统通过 HTTP 请求调用 Yuxi 的对话接口，需要在请求头中携带 API Key。流式接口地址为 `POST /api/chat/agent`，非流式接口地址为 `POST /api/chat/agent/sync`（不支持 HITL）。请求头需要包含 `Authorization` 字段，值格式为 `Bearer <api_key>`，其中 `<api_key>` 是创建 API Key 时获取的完整密钥。请求体为 JSON 格式，必填字段为 `query` 和 `agent_config_id`，可选字段为 `thread_id`、`image_content` 和 `meta`。
 
 以下是一个典型的 Python 调用示例：
 
@@ -22,14 +22,14 @@ API Key 是一种用于身份验证的密钥字符串，外部系统可以通过
 import requests
 import json
 
-url = "http://your-yuxi-server/api/chat/agent/agent_id"
+url = "http://your-yuxi-server/api/chat/agent"
 headers = {
     "Authorization": "Bearer yxkey_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
     "Content-Type": "application/json"
 }
 payload = {
     "query": "你好，请介绍一下你自己",
-    "config": {},
+    "agent_config_id": 1,
     "meta": {}
 }
 
@@ -47,7 +47,7 @@ for line in response.iter_lines():
 
 `event: data` 表示数据事件，携带实际的对话内容。`event: error` 表示错误事件，当对话过程中发生错误时会收到此类事件。`event: done` 表示完成事件，标志对话结束。
 
-每次调用都会在响应中包含 `request_id`，这是本次对话的唯一标识符，可用于日志追踪和问题排查。如果需要在多轮对话中使用同一个会话，可以通过 `config.thread_id` 参数指定线程 ID，系统会将同一线程的消息串联起来形成连贯的对话上下文。
+每次调用都会在响应中包含 `request_id`，这是本次对话的唯一标识符，可用于日志追踪和问题排查。如果需要在多轮对话中使用同一个会话，可以通过 `thread_id` 参数指定线程 ID，系统会将同一线程的消息串联起来形成连贯的对话上下文。
 
 ## 认证方式
 
diff --git a/docs/agents/agents-config.md b/docs/agents/agents-config.md
index 571e3b5b..78db7171 100644
--- a/docs/agents/agents-config.md
+++ b/docs/agents/agents-config.md
@@ -177,7 +177,7 @@ Context 的价值不只在“配置页面”。它贯穿了从配置加载到实
 当前主流程在 `chat_service.py` 中：
 
 1. 通过 `agent_config_id` 查找配置
-2. 若未指定，则获取该部门下该 Agent 的默认配置
+2. 读取该配置绑定的 `agent_id`
 3. 取出 `config_json.context`
 4. 与 `user_id`、`thread_id` 合并成运行时输入
 
diff --git a/docs/develop-guides/roadmap.md b/docs/develop-guides/roadmap.md
index fd9eaa81..65ad3b46 100644
--- a/docs/develop-guides/roadmap.md
+++ b/docs/develop-guides/roadmap.md
@@ -47,6 +47,7 @@
 
 ### 修复
 
+- 重构聊天接口请求模型：流式与非流式聊天统一使用 `query + agent_config_id` 请求体，并移除路径中的 `agent_id`；同时修复非流式接口实际误走流式执行链路的问题，改为调用 `invoke_messages` 一次性执行，并补充对应测试
 - 为沙盒与 viewer 文件系统补齐知识库只读映射：新增 `/home/gem/kbs` 命名空间，按“用户可访问知识库 ∩ 当前 Agent 已启用知识库”暴露原始文件与解析后的 Markdown，并补充对应后端与 viewer 路由测试
 - 修复前端工具图标与渲染匹配不准确的问题：工具管理列表与工具调用结果统一改为基于工具 `id` 的精确映射，避免模糊匹配导致的误渲染，未命中的工具不再显示默认扳手图标
 - 修复 GitHub Pages 文档部署工作流失败：移除 `actions/setup-node@v4` 对不存在 `docs/package-lock.json` 的缓存依赖，并将 `docs` 目录安装命令从 `npm ci` 调整为 `npm install`，避免因未提交锁文件导致 CI 在依赖缓存和安装阶段直接失败
diff --git a/docs/intro/quick-start.md b/docs/intro/quick-start.md
index 4ac8a105..630c0c3a 100644
--- a/docs/intro/quick-start.md
+++ b/docs/intro/quick-start.md
@@ -3,7 +3,7 @@
 欢迎使用 Yuxi（语析），这是一个智能知识库和知识图谱 Agent 开发平台。
 本指南将帮助你在几分钟内启动并运行系统，使你能够利用 LangGraph、RAG 技术和知识图谱构建 AI 驱动的知识应用。
 
-![系统架构图](https://private-user-images.githubusercontent.com/35524243/559928805-96742b56-eda7-4aae-a4df-6fe9d3c30fd1.png?jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.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.uw8QmYsqyXDoEP8wLPHvUYdhS2qbCo2engwiaprs-VM)
+![系统架构图](https://xerrors.oss-cn-shanghai.aliyuncs.com/github/image-20260326130844668.png)
 
 
 ::: tip 提示
diff --git a/web/src/apis/agent_api.js b/web/src/apis/agent_api.js
index 655cd77b..0ee2a01f 100644
--- a/web/src/apis/agent_api.js
+++ b/web/src/apis/agent_api.js
@@ -22,18 +22,17 @@ import { useUserStore } from '@/stores/user'
 export const agentApi = {
   /**
    * 发送聊天消息到指定智能体（流式响应）
-   * @param {string} agentId - 智能体ID
    * @param {Object} data - 聊天数据
    * @returns {Promise} - 聊天响应流
    */
-  sendAgentMessage: (agentId, data, options = {}) => {
+  sendAgentMessage: (data, options = {}) => {
     const { signal, headers: extraHeaders, ...restOptions } = options || {}
     const baseHeaders = {
       'Content-Type': 'application/json',
       ...useUserStore().getAuthHeaders()
     }
 
-    return fetch(`/api/chat/agent/${agentId}`, {
+    return fetch('/api/chat/agent', {
       method: 'POST',
       body: JSON.stringify(data),
       signal,
@@ -190,14 +189,15 @@ export const agentApi = {
 
   /**
    * 创建异步运行任务（Run）
-   * @param {string} agentId - 智能体ID
    * @param {Object} data - run 请求体
    * @returns {Promise<Object>}
    */
-  createAgentRun: (agentId, data) =>
-    apiPost(`/api/chat/agent/${agentId}/runs`, {
+  createAgentRun: (data) =>
+    apiPost('/api/chat/runs', {
       query: data.query,
-      config: data.config || {},
+      agent_config_id: data.agent_config_id,
+      thread_id: data.thread_id,
+      meta: data.meta || {},
       image_content: data.image_content || null
     }),
 
diff --git a/web/src/components/AgentChatComponent.vue b/web/src/components/AgentChatComponent.vue
index 2fbdc3b2..bfda818a 100644
--- a/web/src/components/AgentChatComponent.vue
+++ b/web/src/components/AgentChatComponent.vue
@@ -928,10 +928,8 @@ const sendMessage = async ({
 
   const requestData = {
     query: text,
-    config: {
-      thread_id: threadId,
-      agent_config_id: selectedAgentConfigId.value
-    }
+    thread_id: threadId,
+    agent_config_id: selectedAgentConfigId.value
   }
 
   // 如果有图片，添加到请求中
@@ -940,7 +938,7 @@ const sendMessage = async ({
   }
 
   try {
-    return await agentApi.sendAgentMessage(agentId, requestData, signal ? { signal } : undefined)
+    return await agentApi.sendAgentMessage(requestData, signal ? { signal } : undefined)
   } catch (error) {
     handleChatError(error, 'send')
     throw error
@@ -1170,12 +1168,10 @@ const handleSendMessage = async ({ image } = {}) => {
     resetOnGoingConv(threadId)
     threadState.isStreaming = true
     try {
-      const runResp = await agentApi.createAgentRun(currentAgentId.value, {
+      const runResp = await agentApi.createAgentRun({
         query: text,
-        config: {
-          thread_id: threadId,
-          agent_config_id: selectedAgentConfigId.value
-        },
+        agent_config_id: selectedAgentConfigId.value,
+        thread_id: threadId,
         image_content: image?.imageContent
       })
       const runId = runResp?.run_id