Asynchronous, Long-Running AI Agents with Google ADK

This article argues that most real AI agents run for minutes to days and should be treated as asynchronous systems rather than chat sessions, and walks through building async agents with Google's Agent Development Kit. It covers the Runner, SessionService (in-memory vs. database), Events, FunctionCalls and RequestInput, then shows a fire-and-forget pattern using HTTP 202 responses and webhooks, plus human-in-the-loop pausing and resuming via interrupt IDs and ResumabilityConfig. A second part is planned to cover production deployment with Cloud Run, Cloud Tasks and Cloud Scheduler.