Installation

One package, added to an application that already registers WebMCP tools.

Requirements

Requirement	Value
Node.js	22.12 or newer, 24, or 26 or newer. Not 23 or 25.
Browser	A secure context with native document.modelContext
Module type	ESM. Import from a bundler or a native module page.
Model	An OpenAI-compatible HTTP endpoint that you operate

The browser requirement is the strict one. Read Browser setup before you install anything.

Install

pnpm

pnpm add actionwire

npm

npm install actionwire

yarn

yarn add actionwire

bun

bun add actionwire

That is the whole install. The widget, the headless bridge, the WebMCP source, the model adapter, and the types all come from this one package. Its only runtime dependency is @cfworker/json-schema, which validates tool input without generating code, so it works under a strict Content-Security-Policy.

Read moreWhat the package exports

Check the install

Put this on a page that already registered at least one WebMCP tool:

import { createWebMCPSource } from 'actionwire';

const source = createWebMCPSource();
const snapshot = await source.discover();
console.log(snapshot.tools.map((tool) => tool.name));
source.dispose();

The console prints the tool names the page registered. An empty array means the page registered nothing yet, or the tools belong to a different window. A thrown UNSUPPORTED_WEBMCP error means the browser does not expose the API.

Read moreQuickstart