Building AI Agents with the Python Agent Development Kit (ADK) — 2026 Edition (v2)

Summary of 2026 Updates (v2 — Python ADK 2.0 Migration)

This updated edition incorporates several key architectural improvements, production hardening, and dependency upgrades over the initial release:

Python ADK 2.0 Core Upgrade: Upgraded to google-adk>=2.0.0 (google.adk, GA released at adk.dev/2.0/), introducing google.adk.Context for unified tool context management, session state isolation, and callback execution pipelines.

Google Cloud AI Platform Integration: Native authentication auto-detection for Vertex AI (GOOGLE_GENAI_USE_VERTEXAI=TRUE) and Google AI Studio Gemini API Key fallback.

Python Toolchain & Environment: Modern Python runtime support (3.10+ up to 3.13) with structured dependency management via requirements.txt.