cf-webmcp

WebMCP at the edge.

A Cloudflare Worker that equips any website with WebMCP from a single TOML config. Browser-native agents see your site's tools automatically. Desktop MCP clients pair through a dedicated page.

Get started Source on GitHub

How it works

The Worker sits in front of your domain. On every request it does one of two things:

If the request matches a Worker-owned path (manifest, /mcp landing, /_webmcp/exec/*, /_webmcp/health, /llms.txt, /robots.txt, /.well-known/agents.md and its 301 aliases), handle it directly.
Otherwise proxy the request to origin. Two modifications happen on the way back to the visitor:
- HTTP Link header added on every proxied response - HTML, PDF, image, JSON, anything. The header points at the manifest, so an agent doing a HEAD request finds it without parsing a body.
- On HTML responses only (status 200, text/html, UTF-8, path not excluded), HTMLRewriter also injects one <link rel="webmcp"> into <head> and one <script src="/_webmcp/bootstrap.<hash>.js" defer> before </body>. Non-HTML responses pass through unchanged in their body.
- If a [[forms]] block matches the current path, declarative WebMCP attributes are stamped onto matching forms in the HTML response.

What you get

Manifest

Static tool catalogue at /.well-known/webmcp.json.

Auto-registration

Site-wide navigator.modelContext.registerTool for browser-native agents.

Discovery

<link rel="webmcp"> on every page, plus HTTP Link header.

Pairing page

/mcp lands desktop MCP clients with one-line setup.

llms.txt + robots.txt

Augmented with WebMCP discovery hints, idempotently merged.

AGENTS.md

Auto-published at /.well-known/agents.md with 301 aliases for /AGENTS.md and /agents.md.

Form injection

Stamp toolname / tooldescription / toolparamdescription onto existing forms at the edge from a [[forms]] TOML block. No CMS edit.

Five executors

sitemap_filter, rss_feed, dom_extract, http_json, http_get.

Two minutes to deploy

git clone https://github.com/basgr/cf-webmcp
cd cf-webmcp
cp templates/wordpress.toml webmcp.toml
cp wrangler.example.toml wrangler.toml
# edit webmcp.toml + wrangler.toml
npm install
npm run build
wrangler deploy

Three templates ship: default, wordpress, woocommerce.