Build an AI agent with Mastra

Transcript

1. 0 Build an AI agent with Mastra 2025-05-23 第122回NearMe技術勉強会 Cyan Chen
2. 1 Agentic Framework I recently found an AI agent framework called Mastra. https://mastra.ai/
3. 2 Let’s(AI) build Godot game - The plan - an AI agent that build Godot games for users - What is Godot? - An open source game engine that is comparable to Unity https://godotengine.org/ Some famous game. https://store.steampowered.com/ap p/1637320/Dome_Keeper/
4. 3 Why Godot - Godot has sophisticated CLI only dev workflow. - https://docs.godotengine.org/en/latest/tutorials/editor/command_line_tutoria l.html - `godot --version` - Godot is standalone and lightweight. Unity instead is pretty heavy. - And I love indie games. Therefore, I picked this Udemy course and wonder how much AI can do for a small game https://www.udemy.com/course/jum pstart-to-2d-game-development-go dot-4-for-beginners/?couponCode= V2JPLETSLEARN
5. 4 The prompt - System - adapt from OpenHands https://github.com/All-Hands-AI/OpenHands You are a helpful assistant that builds godot games for users. … 1. EXPLORATION: Thoroughly explore relevant files and understand the context before proposing solutions 2. ANALYSIS: Consider multiple approaches and select the most promising one 3. TESTING: * For bug fixes: Create tests to verify issues before implementing fixes * For new features: Consider test-driven development when appropriate 4. IMPLEMENTATION: Make focused, minimal changes to address the problem 5. VERIFICATION: If the environment is set up to run tests, test your implementation thoroughly, including edge cases. - User Build a gem catcher game. The player can move the pad left and right. The gem fall from top. When the gem touch the pad, the gem disappear and user get points. When the gem falls to screen edge. Game over.
6. 5 Bash Tool Just locate the workspace and godot CLI then execute… Operating system is important for commands
7. 6 The result Repo: https://github.com/yukimotochern/mastra-ai-agent-godot-game Claude Sonnet 3.7 - $2.6 Udemy
8. 7 Try Claude 4 Sonnet Not enhance a lot… Gem seems to blow the pad away… Claude 4 picked RigidBody2D instead of a Node the pad as a result collided with it. Bug: RigidBody2d => Node2d
9. 8 Matra Playground - Good for prototyping
10. 9 A problem for Godot - Not all API are stable public API. - Editor seems to touch the code…
11. 10 Conclusion - It’s powerful that one tool can go so far. - I think we need to make LLM first game engine. - Claude 4 is not improving a lot? - Matra is easy to use but still under active iterations. - Maybe RAG or structured query from Godot will help?
12. 11 Thank you