Posted by Alifatisk 5 hours ago
Sites are now expected duplicate effort by manually defining schemas for the same actions — like re-describing a button's purpose in JSON when it's already semantically marked up?
1. This is a contextual API built into each page. Historically site's can offer an API, but that API a parallel experience, a separate machine-to-machine channel, that doesn't augment or extend the actual user session. The MCP API offered here is one offered by the page (not the server/site), in a fully dynamic manner (what's offered can reflect what the state of the page is), that layers atop user session. That's totally different.
2. This opens an expectation that sites have a standard means of control available. This has two subparts:
2a. There's dozens of different API systems available, to pick from, to expose your site. Github got half way from rest to graphql then turned back. Some sites use ttrpc or capnweb or gproto. There hasn't actually been one accepted way for machines to talk to your site, there's been a fractal maze of offerings on the web. This is one consistent offering mirroring what everyone is already using now anyways.
2b. Offering APIs for your site has gone out of favor in general. It often has had high walls and barriers when it is available. But now the people putting their fingers in that leaky damn are patently clearly Not Going To Make It, the LLM's will script & control the browser if they have to, and it's much much less pain to just lean in to what users want to do, and to expose a good WebMCP API that your users can enjoy to be effective & get shit done, like they have wanted to do all along. If webmcp takes off at all, it will reset expectations, that the internet is for end users, and that their agency & their ability to work your site as they please via their preferred modalities is king. WebMCP directs us towards a rfc8890 complaint future, by directly enabling site agency. https://datatracker.ietf.org/doc/html/rfc8890
In an ideal world html documents should be very simple and everything visual should be done via css, with JavaScript being completely optional.
In such a world agents wouldn’t really need a dedicated protocol (and websites would be much faster to load and render, besides being much lighter on cpu and battery)
For example, web accessibility has potential as a starting point for making actions automatable, with the advantage that the automatable things are visible to humans, so are less likely to drift / break over time.
Any work happening in that space?
I tried to play along at home some, play with rust accesskit crate. But man I just could not get Orcas or other basic tools to run, could not get a starting point. Highly discouraging. I thought for sure my browser would expose accessibility trees I could just look at & tweak! But I don't even know if that's true or not yet! Very sad personal experience with this.
I'm not sure if this is really all that much better than, say, a swagger API. The js interface has the double edge of access to your cookies and such.
I think that the github repo's README may be more useful: https://github.com/webmachinelearning/webmcp?tab=readme-ov-f...
Also, the prior implementations may be useful to look at: https://github.com/MiguelsPizza/WebMCP and https://github.com/jasonjmcghee/WebMCP
> Integrating agents into it prevents fragmentation of their service and allows them to keep ownership of their interface, branding and connection with their users
Looking at the contrived examples given, I just don't see how they're achieving this. In fact it looks like creating MCP specific tools will achieve exactly the opposite. There will immediately be two ways to accomplish a thing and this will result in a drift over time as developers need to take into account two ways of interacting with a component on screen. There should be no difference, but there will be.
Having the LLM interpret and understand a page context would be much more in line with assistive technologies. It would require site owners to provide a more useful interface for people in need of assistance.
The problem is fundamentally that it's difficult to create structured data that's easily presentable to both humans and machines. Consider: ARIA doesn't really help llms. What you're suggesting is much more in line with microformats and schema.org, both of which were essentially complete failures.
LLMs can already read web pages, just not efficiently. It's not an understanding problem, it's a usability problem. You can give a computer a schema and ask it to make valid API calls and it'll do a pretty decent job. You can't tell a blind person or their screen reader to do that. It's a different problem space entirely.
This is what permissions are for.
But no MCP server today has tools that appear on page load, change with every SPA route, and die when you close the tab. Client support for this would have to be tightly coupled to whatever is controlling the browser.
What they really built is a browser-native tool API borrowing MCP's shape. If calling it "MCP" is what gets web developers to start exposing structured tools for agents, I'll take it.
That, or they expect that MCP clients should also be running a headless Chrome to detect JS-only MCP endpoints.
Think of it like an "IDE actions". Done right, there's no need to ever use the GUI.
As opposed to just being documentation for how to use the IDE with desktop automation software.
I do like agent skills, but I’m really not convinced by the hype that they make MCP redundant.
Just give your AI agent a little linux VM to play around that it already knows how to use rather than some specialized protocol that has to predict everything an agent might want to do.
Then came mobile phones with their small screens and touch control which forced the web to adapt: responsive design.
Now it’s the turn of agents that need to see and interact with websites.
Sure you could keep on feeding them html/js and have them write logic to interact with the page, just like you can open a website in desktop mode and still navigate it: but it’s clunky.
Don’t stop at the name “MCP” that is debased: it’s much bigger than that