refactor(agent): 按需加载 Agent 运行时 (#6336)

app/agent/contracts.py

@@ -0,0 +1,35 @@
+"""Agent 轻量公共合同，不触发模型、工具或编排运行时加载。"""
+
+import uuid
+from datetime import datetime
+from typing import Any, Optional
+
+from app.schemas.types import ReplyMode
+
+
+def build_display_message(
+    role: str,
+    content: str = "",
+    attachments: Optional[list[dict]] = None,
+    status: str = "done",
+) -> dict[str, Any]:
+    """构造前后端共享的 Agent 会话展示消息。"""
+    normalized_content = content or ""
+    return {
+        "id": f"{role}-{uuid.uuid4().hex}",
+        "role": role,
+        "content": normalized_content,
+        "createdAt": int(datetime.now().timestamp() * 1000),
+        "status": status,
+        "tools": [],
+        "segments": (
+            [{"type": "text", "content": normalized_content}]
+            if normalized_content
+            else []
+        ),
+        "attachments": attachments or [],
+        "choices": [],
+    }
+
+
+__all__ = ["ReplyMode", "build_display_message"]