Latch

Latch provides a single-line JavaScript snippet that exposes website functions like search, add-to-cart, form submission, and navigation as WebMCP tools for AI agents. The script runs client-side, requires no server or build step, and silently no-ops when WebMCP is not present. It also includes an optional attribution feature that captures first-touch marketing parameters, forwards them to GA4, and appends them as client_reference_id to Stripe checkout links.

The one-line script is free and open source forever under the MIT license. You can self-host or load it from latch.tools. If you want the hosted dashboard that shows what agents actually do on your site, you can upgrade to the Pro plan for €19 per month per project.

The script reads the page in a read-only manner and registers the actions an agent needs without altering the site. It detects search boxes to type queries, finds 'Add to cart' controls to click them, maps contact or booking fields into tools, and surfaces main navigation links so agents can move around reliably.

The script is approximately 6 KB in size and has zero dependencies. It degrades silently where WebMCP isn't present, meaning it never breaks your page if the environment is missing. The discovery process is safe by default, ensuring that only necessary actions are exposed to agents.

You can get started by copying the script tag before the closing body tag: <script src="https://latch.tools/latch.js" defer></script>. There is no build step required, and the script runs entirely in the browser without needing a backend server.

The hosted dashboard provides a 90-day history of tool calls, success rates, and a recent feed. It also offers per-agent breakdowns showing which AI browsers are visiting and full event feeds with weekly email summaries.

The script is completely free and open source forever, but the hosted dashboard costs €19 per month per project. The Pro plan includes everything in the Free version plus historical data, per-agent breakdowns, and priority support.

The analytics feature is opt-in and metadata-only. It reports the tool name, outcome, and page path but never captures form contents, query strings, or personally identifiable information (PII).

The script makes zero network calls unless you add a data-key to your script tag. Without a key, Latch operates entirely offline on the client side and does not send any data to a server.

The script is compatible with the WebMCP standard and has been tested in Chrome 149 origin trial and Edge 147. It also supports Atlas and Comet environments as mentioned in the browser compatibility section.

Latch has no reviews on Trustburn yet. Anyone who has used it can write the first review on its Trustburn page.