VibeFast

What is Convex Database?

Convex isn't just a database; it's a backend replacement. It removes the need for API endpoints, specialized sync logic, and manual caching.

If you try to explain Convex to a backend engineer, they might get confused. "Is it a database? Is it a backend? Is it a cache?"

It is all three.

Convex is a managed backend platform designed for one specific goal: Global State Synchronization.

The "Aha!" Moment

In a traditional app (Next.js + Postgres), the data flow is:

  1. Frontend fetches data.
  2. Backend queries DB.
  3. Frontend caches it.
  4. User updates data.
  5. Frontend invalidates cache.
  6. Frontend re-fetches data.

It's brittle.

In Convex, the flow is:

  1. Frontend subscribes to a query.

That's it. When the data changes on the server, Convex pushes the new result to the client automatically. It works exactly like React.useState, but across every user's device simultaneously.

Code Example: A Chat App

Here is how you write a chat backend in Convex. This is the entire backend code:

// convex/messages.ts
import { query, mutation } from "./_generated/server";
import { v } from "convex/values";

// 1. Read messages (Real-time by default!)
export const list = query({
  handler: async (ctx) => {
    return await ctx.db.query("messages").take(100);
  },
});

// 2. Send message
export const send = mutation({
  args: { text: v.string() },
  handler: async (ctx, args) => {
    await ctx.db.insert("messages", { text: args.text });
    // No need to notify anyone. Convex handles it.
  },
});

Because it's "transactional by default," you never have race conditions. If two users send a message at the exact same millisecond, the database handles it perfectly.

Is It Right For You?

YES if you are building:

  • Social apps
  • Task trackers (like Linear)
  • Uber-style apps with live location
  • AI apps where the response streams in

NO if you need:

  • On-premise hosting (it's cloud-only)
  • Direct SQL access (it has its own query language)

VibeFast Pro includes a fully configured Convex setup because for certain types of apps, it feels like cheating.

Build Faster

Ready to build your dream app?

VibeFast Pro is the ultimate boilerplate for vibecoders. Get the production-ready code you need to turn your 'vibes' into reality.

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— Experience the "magic" of Convex pre-configured.