feat: support shared-workspace file flow for matrix

sdk/interface.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 from datetime import datetime
 from typing import Any, AsyncIterator, Literal, Protocol
 
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 
 class User(BaseModel):
@@ -17,10 +17,11 @@ class User(BaseModel):
 
 
 class Attachment(BaseModel):
-    url: str
-    mime_type: str
+    url: str | None = None
+    mime_type: str | None = None
     size: int | None = None
     filename: str | None = None
+    workspace_path: str | None = None
 
 
 class MessageResponse(BaseModel):
@@ -28,6 +29,7 @@ class MessageResponse(BaseModel):
     response: str
     tokens_used: int
     finished: bool
+    attachments: list[Attachment] = Field(default_factory=list)
 
 
 class MessageChunk(BaseModel):