[Release] google/adk-python v2.0.0a1: v2.0.0a1

Google ADK Python v2.0.0a1 introduces a workflow runtime engine for graph-based execution of agentic applications with advanced control flow features, and a Task API enabling structured agent-to-agent delegation. The workflow runtime supports routing, fan-out/fan-in, loops, retries, state management, dynamic nodes, and nested workflows. The Task API provides multi-turn task modes, controlled output, mixed delegation patterns, and human-in-the-loop capabilities, with task agents integrable as workflow nodes.

Key Points

• •Workflow runtime: graph-based execution engine for deterministic agentic app flows
• •Support for advanced control flow: routing, fan-out/fan-in, loops, and retry mechanisms
• •State management and dynamic node creation within workflows
• •Human-in-the-loop integration for both workflows and task delegation
• •Task API enables structured agent-to-agent delegation with multi-turn and single-turn modes
• •Mixed delegation patterns allow flexible agent collaboration strategies
• •Task agents can be embedded as nodes within workflow graphs
• •Nested workflow support for modular and reusable agentic compositions

Workflow Diagram

Concepts