Meeting minutes
Anssi: as a reminder, we'll use IRC-based queue management in this meeting:
https://
Anssi: to suggest agenda topics, use Agenda+ label, e.g.:
Anssi: please welcome our latest new participants
… Mikhail Klimenko from NVIDIA
… Julien Bataille from Rakuten Group
… Vladimir Edouard from University of North Carolina at Chapel Hill
… Yaoming Liu from Huawei
… Amit Varia from Google
… Michael Lorenz from Karlsruhe Institute of Technology
… Sulaiman Alshammari from Gratech
… Jay Mok from PayPal
… Nicolas Couture, Carson Jozefzoon, Shoury Sharma, Felix Lind, Kannadasan Saminathan, Junjie Qiu and Yifan Chen as individual contributors
… welcome all!
Announcements
TPAC 2026 F2F
Anssi: WebML CG F2F confirmed for Tuesday 27 Oct 2026, in Dublin Ireland
… second day of the TPAC 2026 week 26-30 Oct
Anssi: a few logistics things to handle, please register for TPAC 2026 and book your travel and accommodation as soon as you can
… register latest by 01 October 2026:
Anssi: discount rate provided at the meeting hotel:
Anssi: our F2F Agenda is a joint GH issue with the WebML WG to allow the community chime in more easily with suggestions
… we can continue to label Agenda+ interesting issues and consider these candidates for discussion at the F2F
<gb> Issue 39 WebML WG/CG F2F Agenda - TPAC 2026 (Dublin, Ireland) (by anssiko)
Anssi: the Working Group meets on Monday, 26 October 2026, right before the Community Group meeting
… I encourage all participants to attend both days to get the full picture of the WebML community
Anssi: questions, comments?
E-commerce for Humans and AI Agents workshop
Anssi: this W3C workshop aims to share experience of creating content with AI Agents with ecommerce as a particular focus
… the event takes place Sep 8-9, 2026 in Zurich, Switzerland, Google hosts
… workshop agenda has been published:
https://
Anssi: the event is now fully booked, but if you are interested in attending, please reach out to me and I can help you get on the waitlist
… more information about the workshop is available on the W3C's site:
https://
WebMCP polyfill
Repository: webmachinelearning/webmcp
Anssi: issue #252
<gb> Issue 252 Hosting official polyfill for WebMCP (by beaufortfrancois)
Anssi: a proposal to host official polyfill for WebMCP in the webmachinelearning GH org
Anssi: there's a history for hosting polyfills, this is a good fit
… prior we hosted webmachinelearning/
… share your feedback via the issue, we will make a decision in our next meeting
RESOLUTION: The group plans to host an official polyfill for WebMCP in the webmachinelearning GitHub organization. Adoption earliest by our next meeting, feedback via issue #252.
Translator and Language Detector APIs
Repository: webmachinelearning/translation-api
Security considerations for HTML translation
Anssi: issue #78
<gb> Issue 78 Document security considerations for HTML translation (by reillyeon) [Agenda+]
Anssi: Mozilla reviewed the API and suggested the way how HTML fragments are translated needs careful consideration to avoid security issues
… per Reilly's comment translation models expect text, not HTML as input
… possible vector for an injection attack
Reilly: this issue is outcome of time spent trying to respond to issue #60 around whether we could support translating HTML, still unsure whether we can spec this as an API or leave this to developers
<gb> Issue 60 Input formats for translation and language detection (by tomayac)
Reilly: took a look at Firefox whole page translation implementation, found it complicated
… proposing we respond to Mozilla's concerns and document that developers may implement translation along the lines of code snippet provided in the issue
Ehsan: I responded to the issue and support Reilly's proposed approach
… issue #60 has low-hanging fruit for consensus
<gb> Issue 60 Input formats for translation and language detection (by tomayac)
Ehsan: I tried to categorize related issues and proposed possible next steps
Anssi: are you volunteering to update the security considerations?
Ehsan: I'm working on that already
RESOLUTION: The group resolves to document the potential injection attack vector in the security considerations section of the Translator and Language Detector APIs specification. (issue #78)
<gb> Issue 78 Document security considerations for HTML translation (by reillyeon) [Agenda+]
Prompt API
Repository: webmachinelearning/prompt-api
Tool calling, extended thinking, and multimodality
Anssi: issue #209
<gb> Issue 209 Extend the Message format to support tool calling, extended thinking, and multimodality (by nico-martin) [Agenda+]
Anssi: for this issue, I'd want us to understand what gaps there are in the current multimodal and tool call support
… the issue was opened by Nico from Hugging Face, who is implementing a similar API shape for Transformers.js
Reilly: we haven't looked at tool calling lately too much, my recollection is we had something reasonable in this open-loop proposal
… trying to understand the gap with Nico's API implemented in Transformers.js
Sarah: should we defer this for our next meeting?
Reilly: when implementers are ready to think about this we should revisit this
Sarah: we will come to this by the next meeting
<reillyg> explainers-by-googlers/
WebMCP
Repository: webmachinelearning/webmcp
Anssi: I made a few changes to today's WebMCP agenda
… removed issues #186 and #227 that are fixed and closed, added issue #227
<gb> Issue 227 Tool discovery should not be limited to a single traversable navigable (by domfarolino) [Agenda+]
<gb> Issue 186 WebMCP "real-user measurement" (by yoavweiss) [Agenda+]
Anssi: great work by getting these issues addressed ahead the meeting
Wide review
Anssi: in our last meeting we initiated wide review of WebMCP with the TAG, Privacy and Security groups
… first, let's do a debrief on TAG, Privacy and Security reviews to bring the group up to date
… TAG has not yet delivered its review response
… TAG had a discussion on 2026-08-05 with WebML CG participants who were available at that time
Anssi: Dominic shared helpful notes in the TAG review issue:
w3ctag/
<gb> Issue 1238 Incubation: WebMCP (by marcoscaceres) [Progress: in progress] [Review type: CG early review] [Venue: WebML CG] [Missing: Multi-stakeholder support] [Topic: Machine Learning] [Focus: API design (pending)] [Focus: Web architecture
<gb> … (pending)] [Focus: Security (pending)] [Focus: Privacy (pending)] [Focus: Accessibility (pending)] [Focus: Internationalization (pending)]
Anssi: per the meeting discussion, the TAG is still building understanding of WebMCP and its surrounding ecosystem
… I want to thank those who participated for diligently answering the questions and explaining the problem space WebMCP is addressing
… the realization that "more HTML semantics" is a different, complementary, problem space, helps clarify the scope of WebMCP
Dominic: good summary, one of the biggest hang ups is around security, folks not familiar with WebMCP can confuse the proposal with some other features, same-origin policy, mixing data across tabs, we're working hard with Threat Modeling folks at W3C to clarify the threat models for WebMCP and MCP are different
… we're making progress in building shared understanding on these issues
Anssi: did TAG share any estimate when the response would be delivered?
<Ehsan> the discussions in TAG still continues, Marcos already mentioned that today in the issue thread
Dominic: no definite dates shared
Ehsan: TAG discussions are still ongoing, the July discussion was not official TAG position
Dominic: if the TAG wants to have more discussion, we're happy to meet them in future breakouts
… Marcos not being present in the July breakout meant it was of reduced utility
Ehsan: Marcos initiated that discussion but was not in that meeting himself unfortunately
Anssi: privacy review request has been assigned to privacy reviewers and the spec was introduced on the privacy group's July meeting, no official response yet
<gb> Issue 213 WebMCP 2026-06-25 > 2026-08-01 (by domfarolino) [WD] [pending] [REVIEW REQUESTED]
Anssi: security groups have had two sessions in July to discuss WebMCP, with some of our group participants attending
<gb> Issue 135 WebMCP 2026-06-25 > 2026-08-01 (by domfarolino) [REVIEW REQUESTED] [WD]
Anssi: Simone is working on the WebMCP threat modeling exercise
Johann: Simone recently shared a draft for threat modeling, there's progress on this
Anssi: in the second phase of WebMCP wide review, we reach out to the web internationalization (i18n) and web accessibility (a11y) experts
… I'd propose we initiate wide reviews with the i18n and a11y groups in the coming few weeks
… I will coordinate this with the chairs of those groups
… we've already engaged with these groups via our GH issues:
Anssi: we will refer to these issues in our review requests
Anssi: in addition, both the groups provide checklists to catch the most common i18n and a11y issues:
Anssi: we're ought to validate WebMCP against these checklists to ensure we've covered the most important issues in our review process
… in my experience, many questions are geared toward HTML, and may not apply to APIs such as WebMCP
… in these cases we simply provide a rationale for why they don't apply, if not straightforward
… questions, comments, concerns?
Sarah: I know a few people who could help with a11y review
Kannadasan: I've worked in i18n space and can help a bit
Anssi: I will put interested folks willing to contribute in contact with i18n and a11y groups
RESOLUTION: Initiate wide review of WebMCP with the i18n and a11y groups along with collateral materials.
Developer tooling
Anssi: issue #207
<gb> Issue 207 Support developer tooling (by jackfranklin) [Agenda+]
Anssi: I'd like to understand key use cases and requirements for developer tooling wrt WebMCP
… and whether those use cases warrant providing a mechanism to distinguish between developer tools and user-facing tools as proposed
… two use cases are explored in the issue are:
… debugging web app's flickering UI
… debugging web app's state
Anssi: are we converging on the idea of a "devtoolstooldiscovery" event to help developers discover tools that are available for debugging purposes?
Sarah: for developer tooling, we're finding for large-scale apps it is good to have some scoping for tools, we could defer the cascade for tools, need some scoping to plugin Puppeteer and Playwright-style observability tools
Dominic: I think we'd want to standardize developer member in annotations, to be able to distinguish developer tools from non-developer tools
<domfarolino> +1
RESOLUTION: Add a debugging member to Annotation dictionary. (issue #207)
Real-user measurement
Anssi: issue #186
<gb> Issue 186 WebMCP "real-user measurement" (by yoavweiss) [Agenda+]
Anssi: this issue is to discuss how RUM techniques apply to WebMCP
… Yoav wants to find a solution that answers the questions:
… "Is my WebMCP implementation working well at scale?"
… "Did the user achieve what they were trying to do?"
Anssi: are these the core questions?
Yoav: we broke these down to sub questions in a follow up discussion
… some things we need to do are instrumentable
… with toolactivated event
… some other things developers need, e.g. what agents are users using and with what agents we should test with?
… agents may feel confused, was that a good experience for the user regardless?
… I don't know if we can provide these signals to the developer in the granularity required
… e.g. some timestamps could be useful
Dominic: we talk about this internally, my hunch is whether the agent succeeds in representing its user's task, this is something sites want to know even outside WebMCP
… I imagine this taking place outside WebMCP, site could register reporting URL
… WebMCP would be represented in that
… would like to start with something broader and let WebMCP feed into that
… Yoav, how do you think about that?
Yoav: we'd perhaps need some UA String -style mechanism to understand the user's agent
… disconnected from session, developers would need to setup collection infrastructure
… we can have various agent interaction metrics and WebMCP support will improve them, tool calls that are instrumentable
Yoav: let's continue discussion in the issue, reporting API outside WebMCP is interesting, let's explore straw proposals in this space