Christian: Saw discussion from yesterday.

Marcos: Next step of the discussion is gathering the independent thoughts. Discussions around moving this to a WG. Independent from the WebKit position, I documented the concerns in the Slack. I am very concerned and ask the rest of the TAG to have a look. Might have the most significant impact on web architecture I’ve seen, and quite naively so. Needs a larger TAG reviewership because of the API shape and impact.

Slack: https://w3ctag.slack.com/archives/C03RSJGSCJD/p1779960423515319

Matthew: I'm pretty concerned about this for a number of reasons, privacy concerns, whole sort of meta concern about this is very new. We don’t know where it’s gonna go. But: People want to do stuff like this. So if we’re going to say no, can we offer a subset or a minimal part of it that can be used by people to experiment (the web builds itself; people are going to want to do this, so if we can give them a safe way to experiment that won't impact the rest of the platform until it's mature, and we're really sure it's OK to add any part of it)? The Group is aware of the S&P concerns, but the work carries on. From a11y perspective, there’s a lot of potential. Discovering help for very prevalent minor-to-moderate impairments is very difficult in traditional interfaces (people don't identify the barriers they face as ones that could be fixed; they don't discover helpful features that are present). One position wrt WebMCP is that the semantics added here could be added through the a11y tree. Really interesting question, can see both sides of the arguments. Some of the consequences have already come up, where people are stuffing stuff into ARIA attributes that are for agents, not for people. … AT is for people … We really need to think about the consequences.

Matthew: Here's one of the issues I mentioned re accTree: https://github.com/webmachinelearning/webmcp/issues/91

Christian: Remain positive, but let’s collect all of the valid feedback and put it into a draft comment, that is true.

Ehsan: Worried about privacy, group knows about it, and my gut feeling is: This will be exploited. We need to be careful. How can we direct it in the right way without blocking it? Even if the privacy concerns are serious, I think this is going to happen, so we should steer it.

Marcos: Believe this is very bad. webkit is very against this. we've encouraged them to stop that work and make a new forum.

what I realy like is that this really touches now on the semantic web stuff. we now come full circle on every aspect of what hte TAG has done for the past 20 years or whatever. it's so important for accessibility, privacy, not replicating what the web already does so beautifly, so important not to hand the web over to machines in such a naive way. there are use agents that I already know doing simiar stuff without dumping this problem on developers and keeping it in a privacy-insecure way.

Christian: we need a bigger discussion on this. Let's pick it up in next week's plenary.

Marcos: Intro to it... We have AI agents. They are being integrated into all sorts of software, including UAs. The agents can look into a page, figure out what the user is doing here and how can they help (give a summary of the page, or fill in forms, tools/tasks users might need help with). An example might be booking flights for the user (can help people for whom calendars present usability or accessibility barriers).

Idea of WebMCP: web pages are hard for AIs to figure out. We may need to do visual analysis. WebMCP gives agents data structures that, for example, describe a search form to the agent, which is more digestible. It will descirbe the inputs and outputs. We are defining tools (the web apps) that the agents can use to do tasks for the user.

Heather: what fundaementally makes WebMCP different from MCP?

Marcos: The explainer acknowledges this is a misnomer. MCP is a protocol layer Anthropic came up with. This uses concepts from MCP but isn't that. So it mirrors what MCP is but it isn't MCP.

Matthew: This is describing tools - the web apps - that have capabiltiies that your agent in the UA can then use.

Marcos: There are two parts to this - e.g. you could ask the agent to write you an email. Right now, the whole thing (including the subject) will just end up in the 'body' field becuase it doesn't understand the structure. WebMCP allows you to specify where is the subject, the body, etc.

... This is about in-page tooling (not things like (native) apps that the agent could open to do a task).

... I've tried to describe it factually. WebKit found some problems with it, which I will go into...

... It gets interesting when we consider the tooling and agents behaving as assistive technology.

Heather: Checking standards positions. Mozilla thinks it's interesting; monitoring what happens. WebKit is negative. Does Chrome have a position?

Marcos: They're the proponents. (I opened the TAG design-reviews issue.)

Heather: I feel like we need time to read this through in order to have a sensible conversation about it.

Marcos: One of the considerations architecturally is what primitives is this seeking to add to the platform.

Matthew: I haven't read the WebKit position, yet. I have some concerns, but I'll save them until tomorrow