Docs›Agent›Getting Started›Installation

Installation

Detailed setup guide for agent() in your Angular application.

Requirements

1
Angular 20+

agent() uses Angular Signals and the modern injection context API. Angular 20 or later is required.

2
Node.js 18+

Required for the build toolchain and package installation.

3
LangGraph Platform

A running LangGraph agent accessible via HTTP. Can be local (langgraph dev) or deployed (LangGraph Cloud).

Install the package

npm install @ngaf/langgraph

This installs the library and its peer dependencies including @langchain/langgraph-sdk.

Configure the provider

Add provideAgent() to your application configuration. This sets global defaults for all agent instances.

// app.config.ts
import { ApplicationConfig } from '@angular/core';
import { provideAgent } from '@ngaf/langgraph';
import { environment } from '../environments/environment';
 
export const appConfig: ApplicationConfig = {
  providers: [
    provideAgent({
      apiUrl: environment.langgraphUrl,
    }),
  ],
};
Per-call overrides

Any option passed to agent() directly overrides the global provider config. You can set a default apiUrl globally and override it for specific agents.

Environment setup

For local development, configure your environment and run a LangGraph server:

// src/environments/environment.ts
export const environment = {
  langgraphUrl: 'http://localhost:2024',
};
# Start LangGraph dev server
langgraph dev
 
# Your agent will be available at http://localhost:2024

Verify installation

Create a minimal component to verify the setup works. agent() must be called in an injection context (a component field initializer or inside inject()).

// In a component field initializer (injection context)
const test = agent({ assistantId: 'chat_agent' });
console.log(test.status()); // 'idle' — setup is correct

Troubleshooting

Common issues

Version mismatch -- If you see errors about missing APIs or unknown decorators, confirm your Angular version is 20 or later. Run ng version to check. Earlier versions do not support the injection context APIs that agent() relies on.

CORS errors -- If the browser console shows Access-Control-Allow-Origin errors, your LangGraph server is not configured for cross-origin requests. The LangGraph dev server allows all origins by default. For production, make sure your deployment's CORS policy includes your Angular app's domain.

Connection refused -- If you see ERR_CONNECTION_REFUSED, verify your LangGraph server is running and that the apiUrl matches the correct host and port. Run langgraph dev and confirm the server starts at the expected address (default http://localhost:2024).

"NullInjectorError: No provider for AgentConfig" -- You forgot to add provideAgent() to your appConfig providers array. See the Configure the provider section above.

Next steps

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