How to connect Claude Desktop to a site without an API
To connect Claude Desktop to a site without an API, install the Wield bundle, add the Wield browser extension, and then ask Claude in plain words. Claude calls a Wield recipe that makes the same requests the site's own pages make. Those requests run in your own browser, where you are already logged in, so you do not share a password or an API key with anyone.
What you need
- Claude Desktop on macOS, Windows or Linux.
- A Chromium browser: Chrome, Edge, Brave, Arc, Vivaldi, Opera or Chromium. Firefox and Safari are not supported.
- Node.js 20 or newer, only if you use the
npxinstaller. The one-click bundle does not need it when Claude Desktop's own runtime can run the bridge.
Pick one install path:
| Path | Command or file | Use it when |
|---|---|---|
| One-click bundle | wield.mcpb from wield.run/install | You only use Claude Desktop |
| Installer | npx -y wield-mcp init | You also want Claude Code, Cursor or Codex set up in one run |
Install the bundle and extension
- Download
wield.mcpbfrom wield.run/install and double-click it. Claude Desktop asks to install Wield. - Leave the API key field empty. Public recipes work without an account.
- Add the Wield extension to your browser. The full steps, including loading the extension until it is in the Chrome Web Store, are in the quick start. Do not follow any other store link.
- Open the Wield popup in your browser. It should say Bridge connected.
Claude Desktop rewrites its config file while it runs. If you use the installer instead of the bundle, run npx -y wield-mcp init from a terminal, not from inside Claude Desktop, and quit Claude Desktop when the installer asks.
Run a first recipe
Restart Claude Desktop and ask a question a public recipe can answer:
Use Wield to find a train from Berlin to Munich tomorrow morning.
Claude makes two calls:
| Step | Tool | What it sends |
|---|---|---|
| 1 | find_recipe | Your task in your words |
| 2 | run | recipe_id bahn.de/search-connections and params such as from, to and date |
The public train recipe does not need a login, so it runs right away. Read recipes never show an Allow window. Recipes that change data do, and they are covered in the read-only vs write tools guide.
If your site has no recipe
Ask Claude to request one. Claude calls request_recipe:
- In
requestmode, Wield adds the site and your task text to the public request list on wield.run. Only the site and the task are sent. Keep personal details out of the task text. - In
recordmode, you do the task once in your own browser, review a sanitized recording, and Wield builds a private recipe. This needs a Pro or Team plan. See recording a site.
Check status and fix problems
- Ask Claude for
status. It reports whether the browser executor is online, whether the registry is reachable and which sites you are logged in to. - Run
npx -y wield-mcp doctorin a terminal. It checks each link in the chain and prints a fix for each problem. - If a run fails with
executor_offline, open your browser. If it fails withtab_error, reload the Wield extension at your browser's extensions page. - If Claude Desktop does not show Wield's tools, quit it fully, run
initagain, then reopen it. With the bundle, check Settings and then Extensions.
For every error code, read how to debug Wield errors.
FAQ
Do I need an API key?
No. Public recipes work without an account. A Pro or Team key adds private recipes and organization policies. See teams, API keys and policies.
Does Claude see my cookies or passwords?
No. Recipes run in a tab of the site in your browser, so requests carry the cookies your browser already holds. Wield never reads, copies or sends cookies or passwords. Results go from the extension to wield-mcp to Claude on your computer. They do not pass through wield.run.
Can Claude book something without asking me?
No. Every recipe that changes data stops before its first write request and shows an Allow window in your browser. Deny is the default, and two minutes without an answer count as a deny.
Which sites work?
The registry covered 29 sites as of 7 November 2026. Ask Claude to list the sites, or see wield.run/sites. For a site that is not listed, use request_recipe.