A Tiny Multi-Agent Experiment That Explains Multi-Agent Systems
Framework used
- Lightweight Python + LangChain setup
- langchain-openai with a shared ChatOpenAI model (gpt-4o-mini)
- Role-specific system prompts for each agent
- A simple coordinator in app.py to run the pipeline
- Repository: simplemultiagentsystem
The system architecture
The system runs as a simple sequential pipeline:
Pipeline Execution Graph
Input: User Question
Research Agent
Writer Agent (Draft)
Editor Agent
Writer Agent (Revision)
Coordinator
The Coordinator manages the workflow by:
- Passing outputs between agents
- Controlling execution order
- Printing the final results
This keeps each agent simple, while the pipeline stays clear and easy to follow.
Why multi-agent systems matter
Single-agent AI can do a lot: answer questions, summarize, and write code. But when a task gets more complex,
it often helps to split the work up.
That is the core idea behind multi-agent systems: instead of one "do everything" prompt, you assign roles. Each role focuses on one part of the problem, and the pieces are combined into a better final result.
In this post, we walk through a small, runnable-style experiment that shows how a simple group of agents can collaborate to create a clearer explanation than a single prompt alone.
This is the first post in a series. I will start here, build out a simple multi-agent system, and slowly add capabilities to make it more robust. Along the way I will introduce security considerations. The goal is both personal experimentation and a ride along for those interested in multi-agent systems and security.
What is a multi-agent system?
A multi-agent system (MAS) is an AI setup where multiple agents collaborate to solve a problem.
- A specific role
- A focused responsibility
- A clear handoff to the next agent
Instead of one model trying to do everything at once, work is distributed across specialized roles. A quick analogy is a content team:
- Researcher: gathers facts
- Writer: produces a draft
- Editor: reviews and improves it
A multi-agent system works the same way, only the team members are agents.
The goal of this experiment
Use a small multi-agent system to answer one question: "What is a multi-agent system?"
To keep it educational and focused, the experiment uses these constraints:
- Minimal architecture
- The same LLM powers all agents
- No tools
- No memory
- No RAG
- No web search
This isolates the real lesson: orchestration plus role specialization.
Agent roles (what each one does)
- Research Agent: produces concise bullet notes about the question to give the writer useful context
- Writer Agent: turns notes into a readable explanation (draft, then revision based on editor feedback)
- Editor Agent: reviews the draft and suggests improvements; critiques only and does not rewrite
- Coordinator: orchestrates the process and ensures execution order, visibility, and logging
Making collaboration visible
To make teamwork easy to understand, the program prints each stage:
- USER QUESTION
- RESEARCH NOTES
- DRAFT EXPLANATION
- EDITOR FEEDBACK
- REVISED EXPLANATION
- FINAL ANSWER
This turns the system into a learning tool. Instead of a black box, you can watch the explanation improve step-by-step.
Logging and traceability
The experiment produces two helpful logs:
- Detailed interaction log (.log): prompts, agent responses, and handoff messages
- Execution trace (_trace.md): a clean, step-by-step record of the pipeline
Useful for debugging, inspecting behavior, and visualizing how information moves through the system.
Lessons from the experiment
- Specialization improves clarity: roles create more structured output
- Review loops improve quality: editor to writer revision boosts the final explanation
- Multi-agent value shows up fast: benefits appear without complicated infrastructure
Closing thoughts
Multi-agent systems are not about making AI more complicated. They are about structured collaboration.
Even a small pipeline like this demonstrates the key advantage: divide the work, specialize roles, and improve
results through review.
If you want to try it yourself, modify the code and ask new questions. You may be surprised how far a simple agent workflow can go.