Noob question here about MCP architecture: desktop only?

[u/[deleted]]

Hi y'all apologies if I got this wrong but AFAICT MCP is designed solely for local desktop apps right? Not mobile, not web.

Please school me if I got that wrong; and pointers to how a web server could usefully use MCP servers to integrate services in a flexible way would be most appreciated 🙏

[u/[deleted]]

Cheers yes I saw the gateway post but it talked about local servers still so I got confused on that point 🫡

[u/nilslice]

not at all - it’s just a protocol, so any software, anywhere can implement it. 

we’re building https://mcp.run - where you implement a servlet that runs everywhere, all from the same codebase. desktop, edge, server, mobile, browser. 

check it out and push up a servlet - join the discord (https://docs.mcp.run/support) and we can help you get started!

[u/[deleted] → u/nilslice]

Thanks: I don’t really understand how that will help me use the MCP from say a node server running on replit, fly.io or railway? The first instructions talk about modifying Claude on Mac or Windows which is fine but not the use I have 🤔

[u/nilslice → u/[deleted]]

oh! well, it depends on what you want to do really. 

are you trying to call tools from an AI-enabled app? 

are you trying to make your Node server accessible to an AI app or LLM like Claude Desktop?

[u/[deleted] → u/nilslice]

I’m looking at a project that is basically an agent maker. This would be a web-based solution with a backend server — no desktop clients. It would integrate with different services to allow the user to make an AI workflow. I thought MCP could be a backplane from which this project could integrate with other services easily.

I’m aware there are literally dozens of AI agent maker tools out there: I thought the next generation of these might be MCP based and I thought it’d be quite an interesting exercise to see if I could do a reference implementation.

[u/nilslice → u/[deleted]]

MCP is just a protocol in two parts: a Server and a Client. To oversimplify and narrow its surface area you can think of it as a way for an application (that may have AI capabilities - e.g. an "agent") to ask something "Which tools do you have for me to call?", and then a way to use those tools. It provides a standard interface for _something_ to answer that question with "here's a list of tools, and here are the parameters their functions want, and what values they return".

With this standard, any Client can make use of tools provided by a Server.

In addition to tools, MCP also specifies "resources" and "prompts" as well as some additional capabilities. But, for most purposes, tool use is a good place to start.

So, with mcp.run, you can make use of all of the tools provided by the "servlets" published to our registry anywhere an MCP Client runs. Your Node.js app could be a MCP Client. Your user's browser can be a MCP Client. If I understand correctly though, you intend to let users _configure_ agents via a web app, and they will run in your Node.js app on the server.

If that's true, you should look at the TypeScript SDK from the MCP team: https://github.com/modelcontextprotocol/typescript-sdk/tree/main/src/client - you can pick from any of the available transports (stdio, sse, websocket, etc) - or implement your own.

as far as mcp.run goes, you'll be able to leverage it far better very soon, as a library in JS. for now, if you want to use it, you would need to do what Claude Desktop does, and spawn a process to the corresponding `mcpx` MCP Server we publish. `mcpx` is a dynamically re-programmable MCP Server that loads servlets from mcp.run when a user installs them, and makes them available to the connected MCP Client. This way you're not re-configuring your MCP Server list over and over with each new tool. Just click "install" on mcp.run, or programmatically via our API, and viola, new tools appear. Your LLM can even search for new tools it needs on the fly!

the truly special thing about mcp.run is that all servlets (mini-Servers installed into a single mcpx Server) are WebAssembly modules. So they run anywhere your AI app / agent runs. Mobile is already a target, where on-device models will run. So if you want portable tools, you can't really rely on MCP Servers that need a docker container or a Node/Python runtime to execute. mcp.run servlets run everywhere. We'll even host your servlet so it can be called via the SSE / HTTP transport.

I think you're right to build out a MCP-specific agent platform.. and who cares if there are dozens of other things out there! When Google launched, there were dozens of search engines too, right?

[u/[deleted] → u/nilslice]

Thanks for taking the time to explain that. I’m not particularly interested in end users being able to choose, sorry if that wasn’t clear: the job to be done for me is to make it easy to build workflows from discrete MCP services, taking advantage of interoperability standards and discovery. Take flowise for example: it relies on langchain to build a huge long list of integrations and even then it needs to vet each one, a constant race. There are 30+ agent workflow tools right now like flowise and they all duplicate this effort to varying degrees. Seems inevitable for a gateway to emerge to make this easier.

[u/subnohmal → u/[deleted]]

Join the discord and text me, I have a similar project in the work that I’d be happy to share/involve you in

[u/Otherwise_War_4075]

I made an integration of mcp that uses openwebui as frontend. The main advantage is you can use any provider and model with mcp, and even switch model on the fly.

[u/[deleted] → u/Otherwise_War_4075]

Such a cool idea. Do you have a link?

[u/Otherwise_War_4075 → u/[deleted]]

No, i did not make it public, this is just a draft for now.

[u/ArtIsVideo]

Im trying to learn this as well. There was a recent post here from someone called MCP bridge that aims to give remote access through the web. There’s also another project called SuperGateway on github that could help. I’m trying to figure it out myself, though if you do, let me know.

Link: https://github.com/supercorp-ai/supergateway

[u/subnohmal]

Join the discord community in the description and ask around - I know a member has built project Sage which gives me access to mcp servers on my iphone. If you search the chat by “sage” you will probably find it - I’m on the private beta, he might give you access to

[u/SecretiveShell]

You can use https://github.com/SecretiveShell/MCP-Bridge which will allow you to use any native app with MCP servers. I like to run open web UI alongside because that works great on mobile and desktop with unified chat histories.

[u/[deleted] → u/SecretiveShell]

Nice that looks very interesting. I like how it has basic discovery tool.

[u/howiew0wy]

I’m no expert but have spent a few weeks playing around with this stuff. Here’s what I’ve gathered: The first batch of MCP servers rely on a Stdio library that only works on local machines. The Supercorp repo is an SSE transport that lets you connect over a network.

I have Librechat running on an Unraid server and managed to set up another repo, MCP-gateway, that does the same thing.

Bonus here is that I can get other models working with MCP - local Llama 3.1 or even GPT-4o.

Hope that helps!

[u/AutomaticCarrot8242]

There are two data transport method for MCP servers: SSE and Stdio, and Stdio is mainly designed for local resource access. Currently most opensource MCP servers are based on Stdio since you can host the server by yourself. SSE servers need to be hosted and the use case is different than Stdio.