> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zocomputer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Use MCP App

> Call a server tool through an open MCP App.

## Parameters

<ParamField path="app_id" type="string" required={true}>
  App instance ID from open\_mcp\_app in this conversation.
</ParamField>

<ParamField path="tool_name" type="string" required={true}>
  Exact server tool name.
</ParamField>

<ParamField path="arguments" type="object" required={true}>
  Tool arguments matching its input schema.
</ParamField>