Multi-Agent Systems
A multi-agent system uses several specialized agents — usually coordinated by an orchestrator — to tackle one big task, gaining focus and parallelism at the cost of more complexity, latency, and spend.
Explain like I'm new to AI
Instead of one agent doing everything, a multi-agent system is a team: several agents, each good at one thing, working together. A common setup has a supervisor (orchestrator) that receives the goal and delegates sub-tasks to specialist agents, then combines their results.
Each specialist has its own focused instructions and tools, so it does its part well — like a research team with a manager.
Mental model
A company org chart: a manager (supervisor) splits a project among a researcher, an engineer, and a writer. Each expert focuses on their piece; the manager coordinates and assembles the final result. More people can mean faster work — or more coordination overhead.
How it works
Common patterns:
- Supervisor / orchestrator: one coordinator plans and routes sub-tasks to workers, then merges outputs. Most common and controllable.
- Pipeline: agents hand off in sequence (agent A's output → agent B's input).
- Parallel: independent sub-tasks run at once, then results are combined (fan-out/fan-in).
- Peer collaboration / debate: agents critique or debate to improve quality.
Each agent has its own role, prompt, tools, and sometimes memory, communicating via messages.
Real-world example
A "deep research" system: a supervisor breaks a question into sub-topics, spins up several researcher agents to investigate each in parallel, then a writer agent synthesizes their findings into a report. The parallelism covers more ground quickly, and separation keeps each agent's context focused.
Technical explanation
Multi-agent systems help when a task has separable sub-problems or benefits from parallel exploration and context isolation (each agent keeps a clean, focused context instead of one giant shared one). But they add real costs:
- Coordination overhead & failure modes: agents miscommunicate, duplicate work, or deadlock.
- Higher latency and token spend: many agents = many LLM calls.
- Harder debugging & evaluation: errors compound across agents.
Guidance (echoing Anthropic and others): prefer a single agent until you clearly need multiple; multi-agent shines for parallelizable, read-heavy work (like research) and is riskier for tightly-coupled tasks needing shared state. Good orchestration, clear role boundaries, and strong evaluation are essential.
Common mistakes
Reaching for a multi-agent system by default. It multiplies cost, latency, and failure modes. Start with one well-designed agent; only split into multiple when sub-tasks are genuinely separable or parallel.
- Vague role boundaries, so agents duplicate work or step on each other.
- No shared plan/state, so specialists drift out of sync.
When to use it
- Large tasks with separable, parallelizable sub-problems (e.g., research across many topics) or where context isolation clearly helps.
When NOT to use it
- Simpler or tightly-coupled tasks where a single agent is cheaper, faster, and easier to debug.
Alternatives
- A single agent with good tools and planning; a fixed workflow when the sub-task structure is known and static.
Quick quiz
Related concepts
- Planning & Reflection — Planning breaks a goal into sub-tasks before acting, and reflection lets the agent critique and fix its own work — together they make agents far more reliable.
- The Agent Loop — The agent loop is the cycle of observe, reason, plan, and act that repeats — using tools and results — until the agent reaches its goal.
- Design a Research or Multi-Agent System — Default to one researcher with search tools; add parallel gatherers only when sub-questions are independent — cap cost, keep citations, and don't share god tools.
Last reviewed: 2026-09-04 · Written by ByHeart AI · Reviewed by ByHeart AI