Building a DND Agent with ADK, Antigravity, and Gemini 3

Description

Nohe breaks down how he built a “Campaign Agent” for Dungeons & Dragons/Pathfinder. This system uses a loop of specialized agents—including a receptionist, storyteller, rules lawyer, and critic—to generate playable adventures grounded in actual rulebooks using Google Search grounding.

We also explore the Agent Development Kit (ADK), discussing why we prefer it for building sequential and parallel agent loops, how it handles tools (including GitHub MCP), and how to visualize your agent’s logic as a graph.

In this episode:

• 00:00 - Intro: What we do at Google (Firebase, Genkit, GenUI)
• 01:22 - The state of AI Agents
• 02:34 - Building a D&D Campaign Agent
• 07:45 - The Architecture: Storyteller, Rules Lawyer & The Critic
• 09:58 - Why loops are better than single-shot prompts
• 12:41 - What is the ADK (Agent Development Kit)?
• 16:16 - Using GitHub MCP and Tools
• 18:25 - “That sounds like a Cron Job”: When NOT to use AI
• 20:30 - Testing Agents and Vertex AI optimization
• 29:45 - Sneak Peek: Offline-first syncing with Better Auth & PowerSync

Resources & Topics Mentioned:

• ADK: https://google.github.io/adk-docs/
• Firebase Genkit: https://firebase.google.com/products/genkit
• Model Context Protocol (MCP): https://modelcontextprotocol.io/
• Google Vertex AI: https://cloud.google.com/vertex-ai
• PowerSync (Offline-First Sync): https://www.powersync.com/
• Better Auth: https://www.better-auth.com/
• Pathfinder 2e (Archives of Nethys): https://2e.aonprd.com/

Hosts:

• Nohe: Working on Firebase, Genkit, and ADK.
• Rody: Working on Cross-platform full-stack AI and Generative UI.#AI #GoogleCloud #Genkit #ADK #SoftwareEngineering #DND #Pathfinder