A big limitation for skills (or agents using browsers) is that the LLM is working against raw html/DOM/pixels. The new WebMCP API solves this: apps register schema-validated tools via navigator.modelContext, so the agent has structured JSON to work with and can be way more reliable.
WebMCP is currently being incubated in W3C [1], so if it lands as a proper browser standard, this becomes a endpoint every website can expose.
I think browser agents/skills+WebMCP might actually be the killer app for local-first apps [2]. Remote APIs need hand-crafted endpoints for every possible agent action. A local DB exposed via WebMCP gives the agent generic operations (query, insert, upsert, delete) it can freely compose multiple steps of read and writes, at zero latency, offline-capable. The agent operates directly on a data model rather than orchestrating UI interactions, which is what makes complex things actually reliable.
For example the user can ask "Archive all emails I haven't opened in 30 days except from these 3 senders" and the agent then locally runs the nosql query and updates.
The last days I built the WebMCP plugin for the RxDB database [1]
The goal is to let agents interact with apps through explicit tools instead of DOM scraping or visual navigation. This works nicely because agents can run operations directly on the local-first data the UI already uses.
Yes most servers support websockets. But unfortunately most proxies and firewalls do not, especially in big company networks. Suggesting my users to use SSEs for my database replication stream solved most of their problems. Also setting up a SSE endpoint is like 5 lines of code. WebSockets instead require much more and you also have to do things like pings etc to ensure that it automatically reconnects. SEEs with the JavaScript EventSource API have all you need build in:
I use it in production so i can crawl instagram (and others) without paying for proxies. Tor is single threaded so I have 6 docker containers that run tor proxies to get more bandwith out of it. The best thing about tor is that you set it up once and it will work forever for free.
Author here. The article is mostly about web apps. How would your signaling server emit new connection updates to clients in the scenario you describe?
WebMCP is currently being incubated in W3C [1], so if it lands as a proper browser standard, this becomes a endpoint every website can expose.
I think browser agents/skills+WebMCP might actually be the killer app for local-first apps [2]. Remote APIs need hand-crafted endpoints for every possible agent action. A local DB exposed via WebMCP gives the agent generic operations (query, insert, upsert, delete) it can freely compose multiple steps of read and writes, at zero latency, offline-capable. The agent operates directly on a data model rather than orchestrating UI interactions, which is what makes complex things actually reliable.
For example the user can ask "Archive all emails I haven't opened in 30 days except from these 3 senders" and the agent then locally runs the nosql query and updates.
- [1] https://webmachinelearning.github.io/webmcp/
- [2] https://rxdb.info/webmcp.html