Google Agent Development Kit (ADK)
Google's Agent Development Kit (ADK) is a flexible framework for building AI agents and multi-agent systems. It supports LLM agents, workflow agents, and custom agents with capabilities including MCP tool integration, OpenAPI tools, function tools, grounding via Google Search, streaming via Gemini Live API, and Agent-to-Agent (A2A) protocol for inter-agent communication. Available in Python, TypeScript, Go, and Java.