fix(context): unify context_window_size fallback defaults across channels

backend/app/api/dingtalk.py

@@ -14,6 +14,7 @@
 from app.core.security import get_current_user
 from app.database import get_db
 from app.models.channel_config import ChannelConfig
+from app.models.agent import DEFAULT_CONTEXT_WINDOW_SIZE
 from app.models.user import User
 from app.schemas.schemas import ChannelConfigOut
 
@@ -167,7 +168,7 @@ async def process_dingtalk_message(
             logger.warning(f"[DingTalk] Agent {agent_id} not found")
             return
         creator_id = agent_obj.creator_id
-        ctx_size = agent_obj.context_window_size if agent_obj else 20
+        ctx_size = (agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE) if agent_obj else DEFAULT_CONTEXT_WINDOW_SIZE
 
         # Determine conv_id for session isolation
         if conversation_type == "2":

backend/app/api/discord_bot.py

@@ -12,6 +12,7 @@
 from app.core.security import get_current_user
 from app.database import get_db
 from app.models.channel_config import ChannelConfig
+from app.models.agent import DEFAULT_CONTEXT_WINDOW_SIZE
 from app.models.user import User
 from app.schemas.schemas import ChannelConfigOut
 
@@ -300,7 +301,7 @@ async def handle_in_background():
                 agent_r = await bg_db.execute(select(AgentModel).where(AgentModel.id == agent_id))
                 agent_obj = agent_r.scalar_one_or_none()
                 creator_id = agent_obj.creator_id if agent_obj else agent_id
-                ctx_size = agent_obj.context_window_size if agent_obj else 20
+                ctx_size = (agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE) if agent_obj else DEFAULT_CONTEXT_WINDOW_SIZE
 
                 # Find-or-create platform user for this Discord sender
                 from app.models.user import User as _User

backend/app/api/feishu.py

@@ -11,6 +11,7 @@
 from app.core.security import get_current_user
 from app.database import get_db
 from app.models.channel_config import ChannelConfig
+from app.models.agent import DEFAULT_CONTEXT_WINDOW_SIZE
 from app.models.user import User
 from app.models.identity import IdentityProvider
 from app.schemas.schemas import ChannelConfigCreate, ChannelConfigOut, TokenResponse, UserOut
@@ -405,7 +406,7 @@ async def process_feishu_event(agent_id: uuid.UUID, body: dict, db: AsyncSession
             agent_r = await db.execute(select(AgentModel).where(AgentModel.id == agent_id))
             agent_obj = agent_r.scalar_one_or_none()
             creator_id = agent_obj.creator_id if agent_obj else agent_id
-            ctx_size = agent_obj.context_window_size if agent_obj else 100
+            ctx_size = (agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE) if agent_obj else DEFAULT_CONTEXT_WINDOW_SIZE
 
             # Pre-resolve session so history lookup uses the UUID  (session created later if new)
             _pre_sess_r = await db.execute(
@@ -1045,7 +1046,7 @@ async def _handle_feishu_file(db, agent_id, config, message, sender_open_id, cha
         _sess.last_message_at = _dt.now(_tz.utc)
 
         # Load conversation history for LLM context
-        ctx_size = agent_obj.context_window_size if agent_obj else 100
+        ctx_size = (agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE) if agent_obj else DEFAULT_CONTEXT_WINDOW_SIZE
         _hist_r = await db.execute(
             _select(ChatMessage)
             .where(ChatMessage.agent_id == agent_id, ChatMessage.conversation_id == session_conv_id)
@@ -1232,7 +1233,7 @@ async def _call_agent_llm(db: AsyncSession, agent_id: uuid.UUID, user_text: str,
 
     # Build conversation messages (without system prompt — call_llm adds it)
     messages: list[dict] = []
-    ctx_size = agent.context_window_size or 100
+    ctx_size = agent.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE
     if history:
         messages.extend(history[-ctx_size:])
     messages.append({"role": "user", "content": user_text})

backend/app/api/slack.py

@@ -14,6 +14,7 @@
 from app.core.security import get_current_user
 from app.database import get_db
 from app.models.channel_config import ChannelConfig
+from app.models.agent import DEFAULT_CONTEXT_WINDOW_SIZE
 from app.models.user import User
 from app.schemas.schemas import ChannelConfigOut
 
@@ -238,7 +239,7 @@ async def slack_event_webhook(
     agent_r = await db.execute(select(AgentModel).where(AgentModel.id == agent_id))
     agent_obj = agent_r.scalar_one_or_none()
     creator_id = agent_obj.creator_id if agent_obj else agent_id
-    ctx_size = agent_obj.context_window_size if agent_obj else 20
+    ctx_size = (agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE) if agent_obj else DEFAULT_CONTEXT_WINDOW_SIZE
 
     # Find-or-create platform user for this Slack sender
     from app.models.user import User as _User

backend/app/api/teams.py

@@ -18,7 +18,7 @@
 from app.core.permissions import check_agent_access, is_agent_creator
 from app.core.security import get_current_user
 from app.database import get_db
-from app.models.agent import Agent as AgentModel
+from app.models.agent import Agent as AgentModel, DEFAULT_CONTEXT_WINDOW_SIZE
 from app.models.audit import ChatMessage
 from app.models.channel_config import ChannelConfig
 from app.models.user import User
@@ -499,7 +499,7 @@ async def teams_event_webhook(
         # Load history
         agent_r = await db.execute(select(AgentModel).where(AgentModel.id == agent_id))
         agent_obj = agent_r.scalar_one_or_none()
-        ctx_size = agent_obj.context_window_size if agent_obj else 20
+        ctx_size = (agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE) if agent_obj else DEFAULT_CONTEXT_WINDOW_SIZE
 
         history_r = await db.execute(
             select(ChatMessage)

backend/app/api/websocket.py

@@ -12,7 +12,7 @@
 from app.core.security import decode_access_token
 from app.core.permissions import check_agent_access, is_agent_expired
 from app.database import async_session
-from app.models.agent import Agent
+from app.models.agent import Agent, DEFAULT_CONTEXT_WINDOW_SIZE
 from app.models.audit import ChatMessage
 from app.models.llm import LLMModel
 from app.models.user import User
@@ -459,7 +459,7 @@ async def websocket_chat(
             agent_type = agent.agent_type or ""
             role_description = agent.role_description or ""
             welcome_message = agent.welcome_message or ""
-            ctx_size = agent.context_window_size or 100
+            ctx_size = agent.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE
             logger.info(f"[WS] Agent: {agent_name}, type: {agent_type}, model_id: {agent.primary_model_id}, ctx: {ctx_size}")
 
             # Load the agent's primary model

backend/app/api/wecom.py

@@ -21,6 +21,7 @@
 from app.core.security import get_current_user
 from app.database import get_db
 from app.models.channel_config import ChannelConfig
+from app.models.agent import DEFAULT_CONTEXT_WINDOW_SIZE
 from app.models.user import User
 from app.schemas.schemas import ChannelConfigOut
 
@@ -480,7 +481,7 @@ async def _process_wecom_text(
             logger.warning(f"[WeCom] Agent {agent_id} not found")
             return
         creator_id = agent_obj.creator_id
-        ctx_size = agent_obj.context_window_size if agent_obj else 20
+        ctx_size = (agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE) if agent_obj else DEFAULT_CONTEXT_WINDOW_SIZE
 
         # Distinguish group chat from P2P by chat_id presence
         _is_group = bool(chat_id)

backend/app/models/agent.py

@@ -9,6 +9,8 @@
 
 from app.database import Base
 
+DEFAULT_CONTEXT_WINDOW_SIZE = 100
+
 
 class Agent(Base):
     """Digital employee (Agent) instance.
@@ -74,7 +76,7 @@ class Agent(Base):
     last_daily_reset: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
     last_monthly_reset: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
     tokens_used_total: Mapped[int] = mapped_column(Integer, default=0)
-    context_window_size: Mapped[int] = mapped_column(Integer, default=100)
+    context_window_size: Mapped[int] = mapped_column(Integer, default=DEFAULT_CONTEXT_WINDOW_SIZE)
     max_tool_rounds: Mapped[int] = mapped_column(Integer, default=50)
 
     # Trigger limits (per-agent, configurable from Settings UI)

backend/app/services/discord_gateway.py

@@ -18,6 +18,7 @@
 
 from app.database import async_session
 from app.models.channel_config import ChannelConfig
+from app.models.agent import DEFAULT_CONTEXT_WINDOW_SIZE
 
 try:
     import discord
@@ -170,7 +171,7 @@ async def _handle_message(
                 if not agent_obj:
                     return "Agent not found."
                 creator_id = agent_obj.creator_id
-                ctx_size = agent_obj.context_window_size or 20
+                ctx_size = agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE
 
                 # Find or create platform user for this Discord sender
                 _username = f"discord_{sender_id}"

backend/app/services/wecom_stream.py

@@ -13,6 +13,7 @@
 
 from app.database import async_session
 from app.models.channel_config import ChannelConfig
+from app.models.agent import DEFAULT_CONTEXT_WINDOW_SIZE
 
 
 class WeComStreamManager:
@@ -289,7 +290,7 @@ async def _process_wecom_stream_message(
         if not agent_obj:
             logger.warning(f"[WeCom Stream] Agent {agent_id} not found")
             return "Agent not found"
-        ctx_size = agent_obj.context_window_size or 20
+        ctx_size = agent_obj.context_window_size or DEFAULT_CONTEXT_WINDOW_SIZE
 
         # Conversation ID: differentiate single chat vs group chat
         # Group detection is based on chatid presence, not chattype (SDK bug)