# Add SSR to existing project
ng add @angular/ssr

// app.config.server.ts
import { mergeApplicationConfig, ApplicationConfig } from '@angular/core';
import { provideServerRendering } from '@angular/platform-server';
import { provideServerRoutesConfig } from '@angular/ssr';
import { appConfig } from './app.config';
import { serverRoutes } from './app.routes.server';

const serverConfig: ApplicationConfig = {
  providers: [
    provideServerRendering(),
    provideServerRoutesConfig(serverRoutes),
  ]
};

export const config = mergeApplicationConfig(appConfig, serverConfig);

// app.routes.server.ts
import { RenderMode, ServerRoute } from '@angular/ssr';

export const serverRoutes: ServerRoute[] = [
  { path: '', renderMode: RenderMode.Prerender },           // Static at build time
  { path: 'dashboard', renderMode: RenderMode.Server },      // SSR per request
  { path: 'profile/**', renderMode: RenderMode.Client },     // Client-only (SPA)
  { path: '**', renderMode: RenderMode.Server },              // Default: SSR
];

// app.config.ts - Hydration is enabled by default with @angular/ssr
export const appConfig: ApplicationConfig = {
  providers: [
    provideClientHydration(),  // Included automatically
  ]
};

import { isPlatformBrowser, isPlatformServer } from '@angular/common';
import { PLATFORM_ID, inject } from '@angular/core';

@Component({ ... })
export class MyComponent {
  private platformId = inject(PLATFORM_ID);

  ngOnInit() {
    if (isPlatformBrowser(this.platformId)) {
      // Browser-only code (localStorage, window, DOM manipulation)
      window.addEventListener('scroll', this.onScroll);
    }
  }
}

// Or use afterNextRender for one-time browser init
import { afterNextRender } from '@angular/core';

@Component({ ... })
export class ChartComponent {
  constructor() {
    afterNextRender(() => {
      // Runs only in browser after first render
      this.initChart();
    });
  }
}