A New Standard for Connecting LLMs to External Systems: Anthropic's Model Context Protocol (MCP)
In recent years, as LLMs (Large Language Models) have expanded into diverse applications, there has been a growing need for mechanisms that seamlessly integrate these models with external systems. The Model Context Protocol (MCP) proposed by Anthropic is a new standard protocol that fulfills exactly those requirements. This article explains the basic concepts of MCP, the background of its inception, the current ecosystem, and future prospects, incorporating concrete examples and comments from developers.
1. What is MCP?
1-1. Providing Standardized "Context"
MCP is a protocol for uniformly passing diverse information—such as API calls and internal data—to LLMs as "context." Previously, models could only interact with the outside world through prompts or tools, but MCP standardizes this process, allowing developers to easily build workflows.
"MCP is a very simple way to bring workflows into LLM applications. Whether it's tools or just raw data, you can pass whatever you like as context." (Theo, Anthropic Product Manager)
1-2. The Three Pillars: "Tools," "Resources," and "Prompts"
The main interfaces defined by MCP are the following three:
Tools: Actions that the model can execute in the real world (e.g., file operations, API calls)
Resources: Raw data used in RAG, etc. (text, files, tables, etc.)
Prompts: Template text that users can freely input and edit
With this mechanism, for example, you can call a pre-defined prompt template with a slash command like "/deploy" and start working immediately.
2. From Inception to Open Source
2-1. Background and the Hack Week Breakthrough
MCP originally began from a pressing need among developers at Anthropic to "eliminate the hassle of copy-pasting between IDEs and Claude (Anthropic's model)." After creating a prototype with co-developer Justin, everyone competed to build MCP servers during the company's Hack Week in September 2024.
"From Slack integration to 3D printer control, it was shocking to see that people were turning absolutely everything into MCP servers." (David, Technical Staff)
2-2. Official Launch in November 2024
Following the excitement of Hack Week, MCP was released as open source in November 2024 (around the US Thanksgiving holiday). Overcoming initial confusion over naming and low awareness, it is establishing its position as an "industry-standard integration protocol" through adoption by IDEs, model providers, and major corporations.
3. Current Ecosystem
3-1. From Local to Cloud
While initially focused on developer use in local environments, many cloud-hosted "Remote MCP" servers have now emerged. Through integration with Claude AI, it has become possible to easily incorporate external data and tools via a browser-based interface.
3-2. The Power of Community
As a benefit of being open-source, community-led contributions such as documentation fixes and the addition of sample servers are happening daily. The speed of maintenance is also a key appeal, with things like outdated diagrams being updated immediately via PRs (pull requests).
4. Practical Examples: The 'Magic Moments' Created by MCP
4-1. Controlling 3D Printers and Synthesizers
Particularly impressive are the cases where the LLM directly operates physical devices through MCP. Applications in the creative domain are accelerating, such as generating scripts for Blender to automatically build 3D scenes or playing a home synthesizer via MCP.
"The moment I gave Claude the context and it moved the 3D printer, I felt a sense of magic, as if the model I had just taken out of the box had 'come to life and started moving'." (Hackathon participant)
4-2. Enterprise Deployment
In recent years, the expansion of security features required for enterprise use, such as authentication, authorization, and long-term task management, has also begun. Deployment into the enterprise sector is also in full swing, with specification discussions underway with major software vendors.
5. Future Outlook and Challenges
5-1. Autonomous Exploration via Registry API
As the next major functional expansion, a 'Registry API' is in the works that will allow the model itself to search for and connect to additional MCP servers on demand. This will realize a true agent experience where, rather than being limited to the 10 servers presented by the client, the model can 'discover' new functions as needed.
5-2. Long-running Tasks and User Inquiries
Features such as long-duration batch processing and the ability for the model to re-query the user for missing information (elicitation) mid-process are also under development. The foundation is being laid to utilize LLMs not just for 'one-off interactions,' but for continuous workflows.
Anthropic's Model Context Protocol has achieved a 'standardization of context' that pushes the potential of LLMs to the next stage. Moving forward, it is expected to be widely adopted in both the Web and enterprise sectors as it undergoes further advanced agent functionality and security enhancements. Keep an eye on MCP as it continues to evolve alongside the developer community.