# EP224: MCP vs RAG vs AI Agents

DevFeed: [EP224: MCP vs RAG vs AI Agents](<https://devfeed.tech/articles/ep224-mcp-vs-rag-vs-ai-agents-17986.md>)

Original publisher: [Read original article](<https://blog.bytebytego.com/p/ep224-mcp-vs-rag-vs-ai-agents>)

Author: ByteByteGo

Published: 2026-09-05T15:30:58Z

Content type: article

Language: en

Sources: [ByteByteGo](<https://devfeed.tech/sources/bytebytego.md>)

Topics: [AI Agent](<https://devfeed.tech/topics/ai-agent.md>), [Model Context Protocol](<https://devfeed.tech/topics/model-context-protocol.md>), [Retrieval Augmented Generation (RAG)](<https://devfeed.tech/topics/retrieval-augmented-generation-rag.md>), [distributed-systems](<https://devfeed.tech/topics/distributed-systems.md>), [Publish-subscribe pattern](<https://devfeed.tech/topics/pubsub.md>), [Replication](<https://devfeed.tech/topics/replication.md>)

Tags: [ai-agent](<https://devfeed.tech/tags/ai-agent.md>), [distributed-systems](<https://devfeed.tech/tags/distributed-systems.md>), [mcp](<https://devfeed.tech/tags/mcp.md>), [messaging](<https://devfeed.tech/tags/messaging.md>), [rag](<https://devfeed.tech/tags/rag.md>), [replication](<https://devfeed.tech/tags/replication.md>)

## AI overview

This article compares MCP, RAG, and AI agents. It explains MCP as a standard protocol for connecting AI models to external tools and data, RAG as a way to retrieve current information from external sources, and AI agents as systems that perform tasks and make decisions autonomously. It also summarizes several distributed-systems patterns, including replication, sharding, publish-subscribe, circuit breakers, retries, and leader election.

## Source excerpt

An AI agent is kind of an AI system where the agent performs the task autonomously and takes the decisions.