January 7, 2026
7 min read
By Cruz Morales

Building a Multi-Agent AI System from Scratch

ReactAITypeScriptNext.jsSystem Design

The Challenge: Beyond the Monolithic Chatbot

Most AI chatbots are monolithic. They have a single, general-purpose brain that tries to do everything. But what if we could build a team of specialized AI agents, each with its own unique skills and purpose? That was the challenge we set for ourselves with 11-11, a new Sustainable Intelligence OS. We wanted to create a true thinking partnership, not just a question-and-answer machine.

The Build: A Five-Agent Team

We designed and built a five-agent team, each with a distinct role:

  • The Supervisor: The router and team lead. It analyzes the user's query and routes it to the appropriate specialist agent.
  • The Dojo: The core thinking partner. It has four modes (Mirror, Scout, Gardener, Implementation) to help users explore ideas, map out options, and create action plans.
  • The Librarian: The knowledge expert. It performs semantic searches across the user's knowledge base to find relevant information.
  • The Builder: The code generator. It takes natural language instructions and generates production-ready code artifacts.
  • The Debugger: The quality assurance specialist. It analyzes reasoning, identifies conflicts, and helps resolve logical errors.

We built this system using Next.js, TypeScript, and a custom agent framework. Each agent is a separate module with its own prompt, logic, and API endpoint. The Supervisor uses a description-based routing system to choose the right agent for the job, creating a flexible and extensible architecture.

Key Insights

  • Specialization is Power: By breaking down the problem into specialized roles, we were able to create a more powerful and nuanced AI experience. Each agent can be optimized for its specific task, leading to better results.
  • Routing is Everything: The Supervisor is the most critical component. A smart routing system is essential for a multi-agent architecture to work effectively.
  • Observability is Non-Negotiable: We implemented a Harness Trace system that logs every step of the agent's reasoning process. This is crucial for debugging and understanding how the system makes decisions.

The Result: A True Thinking Partnership

The final product is a multi-agent system that can help users with a wide range of tasks, from brainstorming ideas to writing code. It's a true thinking partnership that goes beyond the limitations of a monolithic chatbot. The next step is to continue refining the agents and adding new specialists to the team.

The Takeaway: Think in Teams

When building complex AI systems, don't think in terms of a single, all-powerful brain. Think in terms of a team of specialists, each with its own unique skills and purpose. This will lead to a more powerful, flexible, and scalable architecture.

Cruz Morales

Cruz Morales

Freelance developer specializing in AI integration and multi-stack development. Based in Madison, WI.

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