---
title: "Add WebMCP search"
description: "Add the WebMCP search tool to a site created before it shipped, so an agent in the reader's browser can search your docs."
---

> Documentation Index
> Fetch the complete documentation index at: https://nimbus-docs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Add WebMCP search

[WebMCP](https://webmachinelearning.github.io/webmcp/) is an experimental browser API that lets a page offer tools to an agent running in the browser. Nimbus registers one tool, `search_documentation`, which searches the site's search index. New sites have it already.

## What new sites get

Nothing loads until an agent calls the tool, and browsers without the API skip it. Results follow the same rules as site search: drafts and hidden versions are left out, and so are `noindex` pages unless they set `searchable: true`.

### Input

| Field | Type | Default | Constraints |
| --- | --- | --- | --- |
| `query` | string | — | Required, at most 500 characters |
| `limit` | integer | `5` | 1 to 20 |
| `version` | string | Every version except deprecated ones | Versioned sites only; any visible version, deprecated included |

**Result:** a list of matches, each with `title`, `heading`, an anchored `url`, and a plain-text `excerpt` of at most 1,000 characters.

### Errors

| Code | Meaning |
| --- | --- |
| `invalid_input` | The query, limit or version is invalid. |
| `index_unavailable` | The search index couldn't load: check that the build's whole `pagefind/` folder is deployed. |
| `search_failed` | The search or its code failed to load. Retry, or reload the page. |

## Add it to an older site

### Prerequisites

- Site search on the default provider (`search` not set to `false` or a custom provider)
- Pagefind 1.5.2 or later

### Steps

1. **Copy the component**

   Copy `src/components/WebMCP.astro` from the [starter](https://github.com/cloudflare/nimbus/blob/main/packages/nimbus-starter-source/src/components/WebMCP.astro) into your project's `src/components/`.
2. **Render it in the head**

   In `src/layouts/BaseLayout.astro`, import the component and render it inside `<head>`:

   ```astro title="src/layouts/BaseLayout.astro"
   ---
   import WebMCP from "@/components/WebMCP.astro";
   ---
   <head>
     <!-- … -->
     <WebMCP />
   </head>
   ```
3. **Build the site**

   ```sh
   npm run build
   ```

### Verify

Open any built page's HTML and find the tool's settings in `<head>`:

```html
<meta name="nimbus-webmcp" content="{&quot;search&quot;:&quot;pagefind&quot;,…}">
```

If the tag is missing, the site's search isn't the default provider. The tool needs a production build: in `astro dev` it answers `index_unavailable`.

## Next steps

- [Remote MCP server](/ai/remote-mcp): let agents outside the browser read your docs.
- [Agent discovery](/ai/agent-discovery): the files agents read to find your site.

Source: https://nimbus-docs.com/ai/webmcp/index.mdx