ng-webmcp

ng-webmcp

Angular library for the WebMCP (Web Model Context Protocol) browser API. Expose your Angular application as an AI-agent-ready tool provider using idiomatic Angular patterns.

Installation

npm install ng-webmcp

Quick Start

Standalone Application

import { bootstrapApplication } from '@angular/platform-browser';
import { provideWebmcp } from 'ng-webmcp';

bootstrapApplication(AppComponent, {
  providers: [provideWebmcp({ fallbackBehavior: 'warn' })],
});

NgModule Application

import { WebmcpModule } from 'ng-webmcp';

@NgModule({
  imports: [WebmcpModule.forRoot({ fallbackBehavior: 'warn' })],
})
export class AppModule {}

Register a Tool via Decorator

import { inject, Injectable } from '@angular/core';
import {
  WebmcpService,
  WebmcpTool,
  registerDecoratedTools,
} from 'ng-webmcp';

@Injectable({ providedIn: 'root' })
export class ProductService {
  private webmcp = inject(WebmcpService);

  constructor() {
    registerDecoratedTools(this, this.webmcp);
  }

  @WebmcpTool({
    name: 'search-products',
    description: 'Search the product catalog',
    annotations: { readOnlyHint: true, untrustedContentHint: true },
    inputSchema: {
      query: { type: 'string', description: 'Search term' },
    },
  })
  async search(args: { query: string }) {
    const results = await this.api.search(args.query);
    return { content: [{ type: 'text', text: JSON.stringify(results) }] };
  }
}

Development Polyfill

import { installWebMcpPolyfill } from 'ng-webmcp/testing';

installWebMcpPolyfill();

Import this before bootstrapping Angular.

Tool annotations

annotations supports readOnlyHint, destructiveHint, idempotentHint, openWorldHint, and untrustedContentHint.

From Chrome 149.0.7810.0, set untrustedContentHint: true for tools returning data from untrusted/external sources.

Publishing

The GitHub Actions release workflow publishes only when the pushed tag exactly matches the library version in projects/ng-webmcp/package.json.

Configure npm Trusted Publisher for this GitHub repository and workflow file before creating the tag. No NPM_TOKEN secret is required.

npm run build:lib
git tag v0.1.0
git push origin v0.1.0

Links

• W3C WebMCP Spec
• GitHub Repo