Toolsmith

Make any site agent-ready with WebMCP. One human click.

---

Agents keep guessing at forms that were built for people. Every wrong guess costs somebody a failed checkout or a broken signup. Toolsmith closes that gap without asking the site owner to write code, and without ever letting an agent approve its own work.

Paste a URL. Toolsmith reads the page, proposes one WebMCP tool per form, drafts a webmcp.js file, and waits. Nothing activates until a person clicks Approve. A receipt comes back, and the file downloads.

There is no language model anywhere in the loop. Every generated line traces to a real field on a real page.

How it works

  URL ──▶ profile_site ──▶ propose_tools ──▶ draft_manifest ──▶ [ Approve ] ──▶ verify_manifest_activation
           read forms       one tool/form     webmcp.js + sha256    human click       receipt + download

Step	Tool	What it does
1	profile_site	Reads the public structure of one page: title, headings, forms and their fields, top-level navigation.
2	propose_tools	Turns the profile into candidate tools. GET forms become read-only tools. POST forms are marked consequential and get a confirm gate.
3	draft_manifest	Emits the webmcp.js source for the chosen candidates, plus the SHA-256 of that exact text.
4	activate_manifest	Shows the approval card and returns a pending request. This tool cannot approve anything on its own.
5	verify_manifest_activation	Reads back the receipt and checks its digest against the manifest stored in the browser.

All five are registered natively on document.modelContext with AbortSignal cleanup.

The approval boundary

The only thing that can activate a manifest is a click on the Approve card. The page checks two properties of that event before it writes a receipt:

• event.isTrusted must be true, so a synthetic click from script does not count.
• navigator.userActivation.isActive must be true, so the click happened inside a real user gesture.

The generated file carries the same discipline forward. Every consequential tool it registers wraps its submit in a browser confirm dialog, so an agent using the output still cannot post a form without a person in the loop.

Try it in 60 seconds

1. Open chudi.dev/tools/toolsmith in Chrome 152 for Testing with the WebMCP flag enabled.

2. Ask the agent:

   Make https://chudi.dev/toolsmith-fixtures/shop.html agent-ready.
   

3. Watch the activity strip fill with profile_site, propose_tools, and draft_manifest.

4. Click Approve.

5. Download the receipt-backed webmcp.js.

Three fixtures are available for testing:

Fixture	What it exercises
shop.html	A single POST add-to-cart form, so the tool gets a confirm gate
newsletter.html	A GET search form beside a POST subscribe form, one read-only tool and one gated tool
empty.html	No forms at all, so the proposal step returns nothing

What is in this repo

These files are extracted from the SvelteKit app that serves chudi.dev, at the commit deployed for the WebMCP Challenge (54bdf5ef0).

src/lib/toolsmith/
  profile.ts      read a page into a structured profile
  propose.ts      map forms to candidate tools
  draft.ts        deterministic webmcp.js template
  register.ts     register the five tools on document.modelContext
src/routes/tools/toolsmith/+page.svelte
                  the page, the activity strip, and the Approve card
src/routes/api/toolsmith/profile/+server.ts
                  server-side fetch and form profiling
static/toolsmith-fixtures/
                  shop.html, newsletter.html, empty.html
scripts/toolsmith-eval.mjs
                  zero-dependency eval runner (unit and end-to-end modes)

The eval runner has two modes:

node scripts/toolsmith-eval.mjs --unit
node scripts/toolsmith-eval.mjs --e2e --url <preview-base>

Why not just ask a chatbot

A chat window returns text. Toolsmith returns a file that runs on your own domain, and only you hold the click that activates it. Anyone can verify the result independently by calling verify_manifest_activation and reading the four fields of the receipt.

License

MIT