Architecture Standards

In this lesson you will learn architecture standards in single-spa, why it matters within governance, and how to use it correctly with clear, copy-ready examples.

Architecture Standards Overview

Architecture Standards is a building block you will reach for often in single-spa. It keeps related logic together and makes your intent obvious to reviewers and future maintainers.

When you learn architecture standards properly, you avoid the guesswork that leads to bugs and rework. The example below shows the shape you will use in most real single-spa projects.

import { registerApplication, start } from 'single-spa';

registerApplication({
  name: '@org/app',
  app: () => System.import('@org/app'),
  activeWhen: ['/app'],
});

start();

single-spa orchestrates multiple framework apps on one page through a root config.

Architecture Standards Example

registerApplication({
  name: '@org/app',
  app: () => System.import('@org/app'),
  activeWhen: ['/app'],
});
start();

Start from a minimal Architecture Standards example and grow it only as needed.
Keep configuration explicit so Architecture Standards behaves the same in every environment.
Name things clearly so teammates understand your Architecture Standards at a glance.
Add tests around Architecture Standards early to lock in expected behaviour.

Single-SPA Cheatsheet

Core single-spa APIs related to architecture standards.

API	Example	Purpose
registerApplication	`registerApplication({ name, app, activeWhen })`	Register a micro frontend
activeWhen	`activeWhen: ['/checkout']`	Route ownership
start	`start()`	Begin routing
bootstrap	`export async function bootstrap()`	One-time setup
mount	`export async function mount(props)`	Render the app
unmount	`export async function unmount(props)`	Clean up the app
import map	`systemjs-importmap`	Locate app bundles

How Architecture Standards Works in Single-SPA

Architecture Standards is part of how single-spa lets multiple applications — even in different frameworks — coexist on one page. A root config registers each app and controls when it is active.

single-spa orchestrates multiple framework apps on one page through a root config.

A root config registers apps and calls start().
Each app exports bootstrap, mount, and unmount lifecycles.
activeWhen decides which routes each app owns.
Import maps resolve each app's bundle at runtime.

Practical Guidance for Architecture Standards

For reliable micro frontends, architecture standards should isolate failures and keep shared state minimal. Let each team own its app end to end while agreeing on a few shared contracts.

Concern	Recommendation
Isolation	One app's crash should not break others
Shared state	Prefer shared utility modules over globals
Routing	Keep activeWhen rules explicit and non-overlapping
Deployment	Release via import-map updates per app

Common Mistakes

Copying architecture standards snippets without understanding what each line does.
Skipping error handling and edge cases when wiring up architecture standards.
Leaving architecture standards untested, so regressions slip into production.
Over-engineering architecture standards before you actually need the extra flexibility.

Key Takeaways

Architecture Standards is a core part of working effectively with single-spa.
Start small and keep architecture standards focused on a single responsibility.
Apply consistent patterns so architecture standards scales across your project.
Test and document architecture standards to keep it maintainable over time.

Pro Tip

Pair architecture standards with automated tests from day one. It is far cheaper to catch single-spa regressions in CI than in production.