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MCP: An (Accidentally) Universal Plugin System
- tonetheman 1y ago[dead]
- croes 1y agoWould be great if we don’t repeat the same mistake over and over again by making security a subsequent feature
- cranberryturkey 1y agocheckout my MCP server platform: https://github.com/profullstack/mcp-server https://github.com/profullstack/mcp-server I built it and have added several modules, but I'm always looking for people to add more modules. See ./mcp_modules in the root folder.
- fxwin 1y agoI'll be honest i read your repository's README.md and still have no idea what this is supposed to be. The tagline sounds like it's for implementing MCP servers, but the endpoints specified further down aren't part of MCP but something more specific (to MCPs serving a language model? Why would we serve them like that?) Also doesn't really seem to relate to the OP beside the term 'MCP' in the title
- cranberryturkey 1y agoIt’s a framework for building mcp servers.
- fxwin 1y agoThen the "Examples" section should include a "How to build a simple MCP server using this framework" section. Instead, it contains an example for an "MCP client" (however the implementation has little to do with what the MCP spec says a client does), and an "example of a custom module for the MCP server" (which MCP server? we haven't built one yet), which (after checking implementation) does not conform to the MCP spec for tools (see https://modelcontextprotocol.io/specification/2025-06-18/server/tools https://modelcontextprotocol.io/specification/2025-06-18/ser...). Unless I'm missing something, this has very little to nothing to do with MCP.
- cranberryturkey 1y agoI implemented some changes, it works now. you can test it out at https://mcp.profullstack.com https://mcp.profullstack.com
- eitland 1y agoHow long before companies start closing this "loophole"? And with the cynicism out of the way, what an insightful and refreshing article!
- ecocentrik 1y agoIf MPC develops as an open standard and this "loophole" gains enough popularity, then companies can only really limit access to their services. This seems like a generally good thing that will enhance automation. In some cases it doesn't really matter if the automation comes from agents, hard coded software or a combination of the two.
- cube00 1y agoI wouldn't call it cynicism. Web services started as the same open utopia. Once everyone was in they jacked up the prices so high it killed the initial consumer apps (eg. Google Maps and Reddit) Nobody is giving access to their walled garden for the good of open-anything. It's what the VCs and stockholders demand and they're the ones putting up the cash to keep this AI hype funded in spite of it running at a loss. Given they haven't put security into MCP yet, I guess they'll need to do that first before they move on reinventing API keys so they can charge for access and hailing that as the next reason the line will go up.
- dragonwriter 1y agoSome remote MCPs will get locked down to know client endpoints, same as any other HTTP service, so if companies are really concerned about them being AI-use-only and don't mind cutting off some AI use to preserve that exclusivity, they’ll lock it down to the big known hosted AI frontends (assuming those end up supporting MCP; the only one I know of that does currently is ChatGPT Deep Research, and only for very limited shapes of servers.) OTOH, that only effects those services, it won't stop people from leveraging MCP as, say, a generic local plugin model for non-AI apps.
- reb 1y agoHas anyone tried Basement's typed xmcp framework [1]? I rolled my own mcp server implementation earlier this summer and it works but it's very basic. I'm considering migrating, but time is limited and I'd love to avoid a dead-end if I can :p [1] https://github.com/basementstudio/xmcp https://github.com/basementstudio/xmcp
- behnamoh 1y agoIs it just me who absolutely hates this much hype around AI while still getting value from AI models? I get it, MCP is useful, but it's neither new nor safe and well thought-out. It feels like everyone now has to write a mandatory MCP article...
- cube00 1y ago> It feels like everyone now has to write a mandatory MCP article... Like this one you can bet every blogspam article is also trying to push something... > The Part Where I Tell You I'm Building Something
- 827a 1y ago> MCP thinks it's for giving context to AI models. But really? It's just a really good protocol for making things talk to other things. MCP has very little utility outside of LLMs. The article begins by saying "but what if we remove the AI", then goes back on that thesis by saying "but if there was an AI between these things, then it becomes a universal plugin system". Which is true, but its missing the critical bit: The AI itself is the universal plugin system, not MCP. And, beyond that, its not even the AI: Its natural language. Language is the universal plugin system. Its not unbelievable that there exists an alternate reality where the Anthropic researchers that invented MCP instead simply leveraged a slightly extended form of OpenAPI specs. The only functional difference is that MCP was a stdin/stdout format first, and added HTTPS later, but sister problems in this domain like LSP just skipped stdin/stdout and went straight to locally-hosted HTTPS anyway. What matters isn't MCP, OpenAPI, or anything like that; what matters is the LLM itself, its tool calling capability, and the tool calling harness. The catalogue of available tools can be in any format; and, truly, the LLM does not care what format its in.
- ethan_smith 1y agoMCP's key innovation isn't the format but its unidirectional, stateless design pattern that makes it fundamentally easier to implement than bidirectional protocols like OpenAPI, which is why it's gaining traction as a universal connector beyond just LLM contexts.
- 827a 1y agoI really don't know where you're coming from with that statement. 1. No one asserted that MCP's key innovation was its format. In fact, what I strongly, almost explicitly implied with my previous comment is that MCP has made no key innovations beyond its marketing system (which does matter and has forced a lot of companies who would never have operated in this space to make an MCP system, and that is good. I like MCP.). 2. MCP is fundamentally bidirectional, not unidirectional. Its a schematized request-response protocol that defines a ton of the same primitives that OpenAPI defines, like available RPC methods, authorization, request parameters, and response schemas [1]. Of course, OpenAPI goes beyond that into HTTP-specific characteristics like status codes, and MCP goes beyond that into LLM-specific characteristics like a prompt catalogue. 3. I'm not aware of any problem domain outside of LLMs that is adopting MCP. In fact, its adoption even within the world of LLMs has been lackluster at best [2]. [1] https://modelcontextprotocol.io/docs/learn/architecture#data-layer-2 https://modelcontextprotocol.io/docs/learn/architecture#data... [2] https://modelcontextprotocol.io/clients https://modelcontextprotocol.io/clients
- do_anh_tu 1y agoI think MCP is awesome, mainly because it forces devs to design the simplest possible tools/APIs/functions so even an average-performance LLM can use them correctly to get things done. As developers, we often want everything to be rich, verbose, and customizable — but the reality is that for most users (and now for AIs acting on their behalf), simplicity wins every time. It’s like designing a great UI: the fewer ways you can get lost, the more people (or models) can actually use it productively. If MCP ends up nudging the ecosystem toward small, well-defined, composable capabilities, that’s a win far beyond just “AI integration.”
- nlawalker 1y agoTotally agree - the true source of all of the value here is the new incentive to write very simple services with very simple documentation and to make that documentation easily discoverable. It fills a gap that exists in most service documentation: an easily discoverable page for developers (specifically, those who already know how to use their ecosystem of choice's HTTP APIs) that has a very short list of the service's most fundamental functionality with a simplified specification so they can go and play around with it.
- brookst 1y agoI don’t like MCP because it relies on good faith from the plugin provider. It works great in closed, trusted environments but it cannot scale across trust boundaries. It just begs for spam and fraud, with badly-behaving services advertising lowest-cost, highest-quality, totally amazing services. It feels like the web circa 1995… lots of implicit trust that isn’t sustainable.
- croes 1y agoToo bad that the S in MCP stands for security
- giantrobot 1y agoI love that MCP servers are rediscovering the old idea of public web APIs mash-ups from the early days of Web 2.0. Of course we don't need any icky XML with its namespace and schemas. Just some vibe-heavy JSON. Snark aside it's, autonomous agents were one of the more interesting justifications for web APIs back in the day. I don't think people necessarily envisioned LLMs but some sort of agent you could send off to grab data or book flights or whatever. Specs like WSDL do what MCP does today letting the autonomous system figure out how to use a service. Oh well, schemas and the ability to do browser-native style transforms were lame! Lets transition to YAML so no one can say "no" to Norway.
- turlockmike 1y agoMCP is just JSON rpc with one useful command (list-tools). Turns out that's probably all we ever needed.
- derwiki 1y agoWSDL has entered the chat
- crazygringo 1y agoPrevious discussion (43 days ago, 355 comments): https://news.ycombinator.com/item?id=44404905 https://news.ycombinator.com/item?id=44404905
- _pdp_ 1y agoThe way the function is described to the LLM matter. Even when the parameters are the same and the effect is the same the title and description can fundamentally influence how the task is performed. The other issue is that you cannot think of MCP servers as universal pluggable systems that can fit into every use-case with minimal wrapping. Real world scenarios require pulling a lot of tricks. Caching can be done at higher or lower level depending on the use-case. Communication of different information from the MCP server also is different depending on the use-case (should we replace these long IDs for shorter IDs that are automatically translated to longer ones). Should we automatically tinyurl all the links to reduce hallucination? Which operations can be effectively solved with pure algorithms (compress 2-3 operations into one) because doing this with LLMs is not only error-prone but also not optimal (imagine using LLM to grep for strings in many files one by one using tool calls rather than using grep to search for strings - not the same) There are so many things to consider. MCP is nice abstraction but it is not a silver bullet. Speaking from experience with actual customers and real use-case.
- pjmlp 1y agoEveryone keeps rediscovering OS IPC extensions via RPC. Not only that, apparently we finally got Jini and Agent Tcl back! https://www.usenix.org/conference/fourth-annual-usenix-tcltk-workshop/agent-tcl-flexible-and-secure-mobile-agent-system https://www.usenix.org/conference/fourth-annual-usenix-tcltk... https://www.eetimes.com/jini-basics-interrelating-with-java/ https://www.eetimes.com/jini-basics-interrelating-with-java/
- gtirloni 1y agoRelevant: https://news.ycombinator.com/item?id=44846871 https://news.ycombinator.com/item?id=44846871
- nnnnico 1y agohow does this hypeblog spam keep getting to the top?
- th0ma5 1y agoThis community has no ability to separate researched information from conjecture, and especially on this topic since neural nets are a black box where we can never know if any behavior is fully intentional or not.
- arrowsmith 1y agoPeople don't read the article, they just comment based on the title. In that respect HN is no different from Reddit.
- sexyman48 1y agoI'm a well-designed hole. Put something here. You asked for it.
- back2dafucha 1y ago[dead]
- cowmix 1y agoI’m just getting into MCP (building my own server and trying some canned ones), and one thing I’ve noticed — some servers seem to devour your context window before you’ve even typed a single token / question. My favorite example is the public Atlassian one — https://www.atlassian.com/blog/announcements/remote-mcp-server https://www.atlassian.com/blog/announcements/remote-mcp-serv... Even with Claude or Gemini CLI (both with generous limits), I run out of context and resources fast. With local LLMs via LM Studio? Forget it — almost any model will tap out before I can get even a simple question in.
- jjani 1y agoLove how the MCPs mimic the company they represent in that sense.
- cowmix 1y agoHeh.. this comment made my day.
- catlifeonmars 1y agoConway’s law in action?
- markerz 1y agoMCPs are the most basic solution possible. Shoving the tool definitions into a vector store and having a subagent search for relevant tools, then another subagent to run the tools would greatly reduce impact on context. I think it’d work in theory, but it’s so annoying to have to do something like this. We’re still in a world where we have some building blocks rather than full fledged toolboxes.
- dragonwriter 1y ago> MCPs are the most basic solution possible. Shoving the tool definitions into a vector store and having a subagent search for relevant tools, then another subagent to run the tools would greatly reduce impact on context. That's a toolchain design approach that is independent of MCPs. A toolchain using MCP could do that and there would be no need for any special support in the protocol.
- Alex_L_Wood 1y agoThe more I look into MCP, the less I understand the hype. It's an OK API that describes how to fetch list of tools and resources and retrieve them, somehow this is supposed to be the standard for AI and environment communication, and...that's it? Am I missing something vital there?
- belter 1y agoMCP "universal plugin system" claims are oversold. It is really just a standardized tool calling for AI agents. If you are not building agents that need to dynamically discover and choose tools, traditional APIs are simpler and better. The "system integration" benefits only matter when you have an LLM in the loop making decisions about which tools to use.
- theusus 1y agoMCP has barely given me satisfactory results. LLMs just keep fighting with it and fill up a lot of their context.
- dragonwriter 1y ago> MCP has barely given me satisfactory results. It's done a good job for me with the tools I've written and connected to LM Studio. I suspect the issue with whether you get satisfactory results is less about MCP qua MCP and more about particular servers and tools.
- ricardobeat 1y agoMade a similar comment [1] a while back. Universal, open APIs might be one of the best things to come out of this AI wave. [1] https://news.ycombinator.com/item?id=44405187 https://news.ycombinator.com/item?id=44405187
- CobrastanJorji 1y agoThis is Web 2.0. You're in the process of rediscovering mashups. Before it was SOAP and REST/HTTP and now it's...well, it's still kind of REST/HTTP because MCP is JSON-RPC. There was this brief, beautiful period where every "learn to code" book ended with a couple of chapters of how to make your app do google searches and throw the results into a word graph or something before all the big tech companies locked that sort of access down. Weirdly, I'm a little optimistic that it might work this time. AI is hot, which means that suddenly we don't care about IP anymore, and if AIs are the ones that are mostly using this protocol, providers will perhaps be in less of a rush to block everybody from doing cool things.
- torginus 1y agoThey don't care about using your IP rights, I doubt it also works the other way around.
- fmbb 1y agoWeb 2.0 was also hot.
- madrox 1y agoYou’re totally right, and that’s why I think this era will fail. Web 2.0 failed because eventually people realized to make money they needed to serve ads, and to do that they needed to own the UI. Making it easy to exfiltrate data meant switching cost was low, too. Can’t have that when you’re trying to squeeze value out of users. Look at the evolution of the twitter API over the 2.0 era. That was entirely motivated by Twitter’s desperate need to make money through ads. Only way we avoid that future is if we figure out new business models, but I doubt that will happen. Ads are too lucrative and people too resistant to pay for things.
- calvinmorrison 1y agowhy cant i serve ads thru my mcp?
- vineyardmike 1y ago
- firasd 1y agoI've been doing some really fun things with MCP First of all I think this kind of localhost/stdio MCP is kind of not 'The Way' besides for playing around. I've been working on SSE/remote/cloud-based MCP Here's a fun example: https://x.com/firasd/status/1945233853414826060 https://x.com/firasd/status/1945233853414826060 ("my landing page is in a text editor with iframe preview. I ask Claude to edit it—the doc gets transcluded into the AI chat, gets surgically edited. I reload. (All on mobile!)") I'm working on a starter template like a DevTools MCP that people can deploy on Cloudflare and oAuth with their github account and it provides tools like url_fetch for people to use privately in their AI chats/tools. First I have to figure out the oAuth stuff myself but will make it a public repo after that and post on here PS. I also think tool use is really underrated and stuff like MCP unlocks a kind of agentic behavior 99% of AI users have never seen.
- stevenhuang 1y agoAccidentally? Generic interoperability was the whole point of mcp, it was not an accident.
- revskill 1y agoThere's nothing about "model" in MCP at all, they're just json rpc ?
- Stwerner 1y agoYep, and the primary transport method is json rpc over stdio
- dragonwriter 1y agoThe “model context” in MCP refers to the motivating application domain (the resources, tool responses, and prompts it provides all, in that use case, are used to populate the model’s context), not the content of the protocol.
- russellbeattie 1y ago> "Your car doesn't care if you're charging a phone or running a personal pizza oven. The hole is the same size. The power is there." This is an inadvertently great and amusing analogy, because it shows how people can assume something about an API's capabilities without actually trying it. A 12V battery car battery can't power a pizza oven. It can barely boil water in a special rice cooker - very very slowly. And it risks depleting the battery and not being able to start your car. Like a new API, people get excited about what it can do, but the reality is very different. I have a portable fan with a power bank that charges over USB with a USB-micro plug. For some reason I can't fathom, it's an absolute power hog. I've killed my van's battery using it for just a few hours. (In theory it should be using at max 2.5W, but that's not the point). Again, that shows how trying to extend an APIs design can have unexpected side effects which tax the system in ways that are hard to predict. MCP has a lot of excitement around it now, but it will inevitably reach its limits. The lesson is to test your system under load before assuming anything.
- xyzzy123 1y agoThis is not a novel take, but what's arguably even more universal is cli access to a service. I have a lot more luck integrating service specific cli's with Claude than trying to use MCPs. As an additional bonus, AI tools instantly know how to troubleshoot issues with them, filter or transform the output and compose them into bigger workflows with scripting.
- AbstractH24 1y agoTools like this have existed for between years and decades. From IFTT/Zapier to N8N to ETLs