feat: add MCP tool integration

backend/services/config_resolver.py

@@ -9,12 +9,14 @@ from db.models import (
     AssistantModelBinding,
     AssistantToolBinding,
     KnowledgeBase,
+    McpServer,
     ModelResource,
     Tool,
 )
 from models import (
     AssistantConfig,
     RuntimeKnowledgeBase,
+    RuntimeMcpServer,
     RuntimeModelResource,
     RuntimeTool,
 )
@@ -102,18 +104,55 @@ async def _tools_for(session: AsyncSession, assistant: Assistant) -> list[Runtim
             .order_by(AssistantToolBinding.created_at, Tool.id)
         )
     ).scalars().all()
-    return [
-        RuntimeTool(
-            id=tool.id,
-            name=tool.name,
-            function_name=tool.function_name,
-            type=tool.type,
-            description=tool.description,
-            definition=tool.definition or {},
-            secrets=tool.secrets or {},
-        )
+    server_ids = {
+        str(tool.mcp_server_id)
         for tool in tools
-    ]
+        if tool.type == "mcp" and tool.mcp_server_id
+    }
+    server_rows = (
+        (
+            await session.execute(
+                select(McpServer).where(
+                    McpServer.id.in_(server_ids),
+                    McpServer.status == "active",
+                )
+            )
+        ).scalars().all()
+        if server_ids
+        else []
+    )
+    servers = {server.id: server for server in server_rows}
+    resolved: list[RuntimeTool] = []
+    for tool in tools:
+        mcp_server = None
+        if tool.type == "mcp":
+            server = servers.get(str(tool.mcp_server_id or ""))
+            if server is None:
+                continue
+            config = server.config or {}
+            secrets = server.secrets or {}
+            mcp_server = RuntimeMcpServer(
+                id=server.id,
+                name=server.name,
+                transport=server.transport,
+                url=server.url,
+                timeout_seconds=int(config.get("timeout_seconds") or 30),
+                headers=dict(config.get("headers") or {}),
+                secret_headers=dict(secrets.get("headers") or {}),
+            )
+        resolved.append(
+            RuntimeTool(
+                id=tool.id,
+                name=tool.name,
+                function_name=tool.function_name,
+                type=tool.type,
+                description=tool.description,
+                definition=tool.definition or {},
+                secrets=tool.secrets or {},
+                mcp_server=mcp_server,
+            )
+        )
+    return resolved
 
 
 async def resolve_runtime_config(