WebBrain Web Tools — LM Studio plugin

Give any LM Studio model the ability to read the live web. Two tools, no browser required:

fetch_url — raw HTTP fetch with content-type smarts. JSON gets pretty-printed, HTML is stripped to readable text + <title>, plain text comes back verbatim, binaries are summarised instead of inlined.
research_url — same fetcher, biased toward "give me the article body, not the navigation chrome." Extracts <main> / <article>, drops header/nav/footer/aside before stripping tags. Best for news, blog posts, READMEs, Wikipedia, docs.

Pure Node — no Puppeteer, no Playwright, no headless Chromium. Same fetching logic the WebBrain browser extension ships, ported off chrome.* onto Node fetch.

Bitcoin price answered live via fetch_url in LM Studio

Install

That pulls the plugin from LM Studio Hub into your local plugins directory. Open LM Studio, click the integrations icon next to the chat input, and toggle webbrain/web-tools on (see screenshot above). Any tool-capable model in the same chat can now call fetch_url and research_url.

Try it:

What's on the front page of news.ycombinator.com right now?

The model should call research_url and come back with live headlines.

What this plugin can't do

Listed up front so it doesn't bite you mid-session:

No JavaScript rendering. Single-page apps that hydrate from JSON (Twitter, Notion, modern dashboards) return near-empty text. The plugin flags this with spaSuspected: true so the model can give up gracefully instead of looping.
No clicks, no typing, no screenshots. Those need a real browser. The WebBrain extension does that; this plugin is the read-only subset.
No cookies, no login. Each fetch is anonymous from your IP with no shared session — pages behind a login are out of reach.

If you need any of the above, install the WebBrain browser extension instead (or alongside) — same model server, full agent loop with browser interaction.

Develop locally

If you want to hack on the plugin, clone this repo (rather than lms clone the published artifact) and:

lms dev bundles src/ and registers the plugin live with your running LM Studio instance — edits to TypeScript files hot-reload without a restart. The dist/ build via npm run build is only needed if you want to import the tool implementations from another Node project.

File layout

tools/ and util/ are pure functions with no SDK dependency — you can import them from any Node project that wants the same web-fetching primitives.

Safety notes

The plugin runs in your local Node process, so anything reachable from that process is reachable from the LLM. The defenses below are layered — each closes a class of bypass the previous one missed — but DNS rebinding is a known residual gap (see end of this section).

Set allowPrivate: true on a per-call basis to opt out of the URL guard + DNS check — useful when you actually want to talk to localhost services.

Known residual gap: DNS rebinding

An attacker controlling a domain with TTL=0 can return a public IP when our guard runs dns.lookup and a private IP a moment later when fetch connects. Closing this fully requires pinning the resolved IP via a custom undici Agent's connect.lookup hook so the connection uses the exact address we validated. Tracked as a follow-up. If you're running this on a cloud VM with sensitive instance-metadata endpoints, use a network policy that blocks 169.254.169.254 outbound rather than relying solely on this plugin's checks.

License

MIT, same as the rest of WebBrain. See ../LICENSE.