Multi-Agent System
A multi-agent system orchestrates multiple specialized AI agents — often LLM-powered, with distinct roles, tools, and prompts — that communicate, coordinate, and divide labor to solve a problem larger or more diverse than any single agent could handle reliably.
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Full definition
Common topologies include planner-worker (one agent decomposes, others execute), debater (agents argue to converge), supervisor-subordinate (hierarchical delegation), and swarm (peer-to-peer with shared scratchpad). Frameworks include Microsoft Agent Framework (successor to the now-archived AutoGen), CrewAI, LangGraph, and Anthropic's reference patterns. Multi-agent improves on single-agent for tasks with parallel sub-goals or where role specialization reduces context bloat.
Why it matters
Multi-agent is also where cost spirals and debugging gets hard: every agent adds latency, tokens, and failure modes. Use multi-agent when sub-tasks genuinely parallelize or specialize; use a single agent with tools otherwise.
Example
A research-report system uses one planner agent, four parallel researcher agents (markets, competitors, financials, regulatory), and one editor agent — producing in 12 minutes what previously took two analysts a day.
Next steps
Related terms
- Agentic WorkflowAn agentic workflow is a multi-step AI process where a model plans, takes actions through tools, observes results, and iterates toward a goal — replacing single-shot prompting with a loop that reasons, acts, and self-corrects.
- AI Agent / Agentic AIAn AI agent is an LLM-driven system that, given a goal, plans a sequence of steps, calls tools or APIs, observes the results, and iterates until the goal is reached — going beyond single-turn chat to multi-step autonomous action.
- ReAct PatternReAct (Reasoning + Acting) is a prompting pattern that interleaves reasoning steps ("Thought") with tool actions ("Action") and tool results ("Observation"), letting an LLM iteratively decompose a task, query the world, and self-correct.
- Tool Use (LLM)LLM tool use is the pattern in which a language model acts through external functions, APIs, databases or code execution: the model requests a tool, the host application runs it and returns the result, and the model continues, turning a text generator into a controller that can act. Function calling is the structured-output mechanism most tool use is built on.
More deployment & operations terms
- Dense Passage Retrieval (DPR)Dense Passage Retrieval (DPR) is a retrieval method that embeds queries and passages into the same vector space using two BERT encoders (a dual encoder) trained with contrastive loss on (question, positive-passage) pairs.
- Embedding ModelAn embedding model is a neural network that maps text, images, or other inputs into fixed-dimensional vectors where semantic similarity corresponds to geometric closeness (cosine or dot-product distance).
- Semantic SearchSemantic search is information retrieval that ranks documents by meaning rather than exact-keyword overlap, using vector embeddings of query and documents to measure similarity in a learned semantic space.
Source & further reading
Primary source: Wu et al. — "AutoGen: Enabling Next-Gen LLM Applications via Multi-Agent Conversation" (Microsoft Research) (2023).
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