Mohamad Msalme

Posted on Aug 30 • Edited on Sep 4

React Query Pattern Changed How you Think About Caching Forever

#react #frontend #nextjs #typescript

Know WHY — Let AI Handle the HOW 🤖

Ever treat React Query cache keys as random arrays? Let's dig deeper into the architectural pattern that changes everything.

The Problem We Are Missing 🤔

AI can teach you HOW to write:

useQuery(['posts', id], fetchPost)

But here's the WHY that transforms your entire caching strategy...

The Pattern Hidden in Plain Sight 👁️

Look at your API routes:

/posts/1
/posts/user/123  
/posts/favorites

Now look at your cache keys:

['posts', 1]
['posts', 'user', 123]
['posts', 'favorites']

See the pattern? Your API structure IS your cache structure.

This is the exact same concept as Next.js cache tags - the first item acts as a namespace for cache invalidation!

Building the Solution: BaseApi Class 🔨

Once you understand the WHY, you can implement a Repository Pattern that gives you all the benefits:

class BaseApi {
  constructor(tag) {
    this.tag = tag;
  }

  invalidateAll() {
    queryClient.invalidateQueries([this.tag]);
  }

  // All your CRUD methods here...
}

class PostApi extends BaseApi {
  constructor() {
    super('posts');
  }
}

const postApi = new PostApi();

The Power Move 🔥

Now you have tagged cache invalidation just like Next.js - but in your React Query app:

// One line invalidates ALL posts-related cache
postApi.invalidateAll()

The Benefits ✨

✅ Backend mutations naturally invalidate frontend cache

✅ Predictable cache boundaries

✅ Scales with your API architecture

The Architecture Insight 🎯

Your cache key architecture should mirror your API architecture.

When you POST/PUT/DELETE on any /posts/* route, invalidate the ['posts'] cache namespace.

This isn't just React Query — it's distributed cache design.

The Real Breakthrough 🧠

Do not think cache keys are just "identifiers." But they're actually:

Hierarchical namespaces that mirror your API structure
Invalidation boundaries for efficient cache management
Architectural decisions that affect your entire data flow

Once you see cache keys as architecture, not random arrays, everything changes.

Implementation Pattern

Here's how this looks in practice:

// Your API structure defines your cache structure
const userApi = new BaseApi('users');
const postApi = new BaseApi('posts');
const commentApi = new BaseApi('comments');

// Mutations automatically invalidate the right caches
const createPost = useMutation(postApi.create, {
  onSuccess: () => {
    postApi.invalidateAll(); // Invalidates all ['posts', ...] keys
  }
});

Why This Matters

When you align your cache architecture with your API architecture:

Cache invalidation becomes predictable
Your frontend naturally stays in sync with backend changes
Scaling becomes a matter of following the established pattern

Remember: Know the WHY behind the pattern, and the HOW becomes crystal clear.

What's your biggest React Query caching challenge? Share your experience in the comments! 👇

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