A guide to Google ADK and MCP integration with an external server

Anthropic's Model Context Protocol (MCP) provides a standardized way to access external context needed for AI-powered agents to perform real-world tasks. MCP enables agents to retrieve external data and tools, which is crucial for developers building sophisticated agents that leverage enterprise data or public APIs. To integrate agents built with Google's Agent Development Kit (ADK) with an MCP server, developers need to connect to an external MCP server using Server-Sent Events (SSE) or Streamable HTTP. This article guides developers through developing ADK agents that connect to external MCP servers, using SSE and Streamable HTTP as examples. To start, developers need to create an MCP server using Python packages and configure an SSE transport mechanism. Then, they need to create an ADK agent and attach the MCP server to it. The agent can then be tested using the ADK developer tool. Streamable HTTP is a new transport protocol that allows servers to function as independent processes managing multiple client connections via HTTP POST and GET requests. For production deployments of MCP servers, robust authentication is critical, and developers should refer to the MCP specification on Authentication for more information. Finally, developers can get started with ADK by reading the documentation and creating their own Agent with access to available MCP servers in the open community.