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Claude Desktop extension · MCP server

Privacy policy

The html.cloud extension for Claude Desktop (the html-cloud-mcp server) is built so that we cannot see the pages Claude shares through it. This page explains exactly what it does with your data. Last updated 2026-09-09.

What we collect

The extension handles only the HTML that Claude passes to its two tools, share_html and update_html, when you ask for a page to be shared or changed. It does not read files on your computer, your conversation, or anything else from Claude. It collects:

  • Personal information: none. No account, no email, no name.
  • Analytics or tracking: none. No telemetry, no crash reporting.
  • Third-party services: none. It communicates only with html.cloud.

How your data is used and stored

When Claude shares a page:

  1. The extension encrypts the HTML on your computer with AES-256-GCM before anything is sent.
  2. What is uploaded to html.cloud: the encrypted bytes (ciphertext), the expiry you chose, a copy of the page key that is itself encrypted with the edit key, and a hash of the edit key so the server can check that later updates are authorised. None of these let us read the page.
  3. The decryption key is placed in the share link, after the #. Browsers never transmit the part of a URL after #, so the key never reaches our server.

html.cloud stores those values. We cannot read the page and cannot recover either key. When Claude updates a page, the new HTML is encrypted under the same page key on your computer, and only the new ciphertext, the page id, and the edit-key proof are sent. The share and edit links are returned to Claude in the conversation; nothing is stored on your computer by the extension itself.

Our servers keep ordinary short-lived request logs (such as IP address and timestamp) to operate the service and prevent abuse, as any web server does. These are not linked to the content of a page, which we cannot read.

Sharing with third parties

We do not sell, share, or transfer data to third parties. The only people who can read a page are those you give the full link to; they decrypt it in their own browser.

Retention

A page becomes unavailable the moment its link expires — 7 or 30 days after sharing, or never if you chose a permanent link — and the stored ciphertext is permanently deleted by a daily clean-up. Deleting a page through its private edit link removes it immediately.

Contact

Questions or requests: email [email protected] or open an issue at github.com/viljamilaurila/html-cloud. The extension's source code is in the mcp/ directory of that repository.