Google ADK Graph Workflows & Custom Agents: Full Control Over Your AI Agents (ADK 2.x) ! #adk

Module 13 of the Google ADK series covers two powerful approaches to agent orchestration: Graph Workflows and Custom Agents. Graph Workflows provide a declarative, visual way to define agent behavior using nodes and edges, while Custom Agents offer programmatic control for complex logic. Together, these tools enable developers to build sophisticated, multi-step AI agent systems with full control over execution flow, state management, and inter-agent communication.

Key Points

• •Graph Workflows enable declarative agent orchestration using visual node-and-edge architecture for clear, maintainable agent logic
• •Custom Agents provide programmatic control for implementing complex business logic and conditional routing that Graph Workflows alone cannot express
• •Combine Graph Workflows and Custom Agents to leverage declarative simplicity for standard flows and programmatic flexibility for edge cases
• •Graph Workflows support state management across nodes, allowing data to flow between agent steps and maintain context throughout execution
• •Custom Agents integrate with the ADK framework to create reusable, composable agent components that can be orchestrated at scale
• •Use Graph Workflows for linear or branching processes; use Custom Agents for dynamic routing, ML model integration, or external API orchestration
• •ADK 2.x provides full control over agent lifecycle, including initialization, execution, error handling, and graceful shutdown
• •Multi-agent systems benefit from clear separation of concerns: Graph Workflows handle orchestration, Custom Agents handle specialized logic

Workflow Diagram

Concepts