MiniKit Quickstart

This guide shows you how to get started with MiniKit, the easist way to build mini apps on Base! It can also be used to update an exisitng standalone app to a mini app. We'll start by setting up the template project with the CLI tool and then explore both built-in and additional features of MiniKit.

Prerequisites

Before you begin developing with MiniKit, you'll need:

1. Farcaster Account: Create an account on Warpcast to test and deploy your Mini Apps.

2. Coinbase Developer Platform Account (Optional): Sign up for a Coinbase Developer Platform account if you need CDP API key for additional functionalities.

What is a Mini App?

A mini app is a lightweight web app that runs directly inside Farcaster Frames, without needing to open a browser or download anything. Built using familiar tools like Next.js and minikit, mini apps behave just like normal apps — but launch instantly from posts, making them feel native to the Farcaster experience.

Initial Setup

npx create-onchain@alpha --mini

cd your-project-name
npm install
npm run dev

Testing Your Mini App

To test your Mini App in Warpcast, you'll need a live URL.

We recommend using Vercel to deploy your MiniKit app, as it integrates seamlessly with the upstash/redis backend required for stateful frames, webhooks, and notifications.

Alternatively, you can use ngrok to tunnel your localhost to a live url.

npm run dev

# Install ngrok if you haven't already
npm install -g ngrok
 
# Create a tunnel to your local server (assuming it's running on port 3000)
ngrok http 3000

Deploying to Vercel

You can now test your mini app:

1. Copy your deployed vercel URL
2. Visit Warpcast Frames Developer Tools on web or mobile
3. Paste URL into "Preview Frames"
4. Tap Launch

Exploring Built-in Features

The template comes with several pre-implemented features. Let's explore where they are and how they work.

MiniKitProvider

The MiniKitProvider is set up in your providers.tsx file. It wraps your application to handle initialization, events, and automatically applie client safeAreaInsets to ensure your app doesn't overlap parent application elements.

import { MiniKitProvider } from '@coinbase/onchainkit/minikit';
 
export function Providers(props: { children: ReactNode }) {
  return (
    <MiniKitProvider
      apiKey={process.env.NEXT_PUBLIC_ONCHAINKIT_API_KEY}
      chain={base}
      config={{
        appearance: {
          mode: 'auto',
          theme: 'snake',
          name: process.env.NEXT_PUBLIC_ONCHAINKIT_PROJECT_NAME,
          logo: process.env.NEXT_PUBLIC_ICON_URL,
        },
      }}
    >
      {props.children}
    </MiniKitProvider>
  );
}

The MiniKitProvider also sets up your wagmi and react-query providers automatically, elimintaing that initial setup work.

useMiniKit

The useMiniKit hook is implemented in your main page component (app/page.tsx). It handles initialization of the frame and provides access to the SDK context.

const { setFrameReady, isFrameReady, context } = useMiniKit();
 
// The setFrameReady() function is called when your mini-app is ready to be shown
useEffect(() => {
    if (!isFrameReady) {
      setFrameReady();
    }
  }, [setFrameReady, isFrameReady]);

Creating the Manifest

The Frame Manifest is required in order for users to save the frame to their account. This means its also required to send notifications to the user. We initially skipped this step when setting up the app. Now that we know our vercel url, we can configure our manifest.

To set up the manifest, run the following in your Terminal

npx create-onchain@alpha --generate

Enter y to proceed with the setup and your browser will open to the following page:

The wallet that you connect must be your Farcaster custody wallet. You can import this wallet to your prefered wallet using the recovery phrase. You can find your recovery phrase in the Warpcast app under Settings -> Advanced -> Farcster recovery phrase.

Once connected, add the vercel url and sign the manifest. This will automatically update your .env variables locally, but we'll need to update Vercel's .env variables.

Create the following new .env variables in your vercel instance and paste the value you see in your local.env file

• FARCASTER_HEADER
• FARCASTER_PAYLOAD
• FARCASTER_SIGNATURE

Now that the manifest is correctly set up, the Save Frame button in the template app should work. We'll explore that below.

useAddFrame

The useAddFrame hook is used to add your mini app to the user's list of mini apps. It's implemented in your main page component and displays a button in the top right allowing the user to add the mini app to their list.

When a user adds the mini app, it returns a url and token, which is used for sending the user notifications. For this walkthrough we'll simply console.log those results to use them later when setting up notifications.

 
const addFrame = useAddFrame()
 
// Usage in a button click handler
const handleAddFrame = async () => {
  const result = await addFrame()
  if (result) {
    console.log('Frame added:', result.url, result.token)
  }
}

useOpenUrl

The useOpenUrl hook is used to open external URLs from within the frame. In the template, its used in the footer button which links to the MiniKit page.

const openUrl = useOpenUrl()
 
// Usage in a button click handler
<button onClick={() => openUrl('https://example.com')}>
  Visit Website
</button>
 
// Then in the return function
<footer className="absolute bottom-4 flex items-center w-screen max-w-[520px] justify-center">
  <button
    type="button"
    className="mt-4 ml-4 px-2 py-1 flex justify-start rounded-2xl font-semibold opacity-40 border border-black text-xs"
    onClick={() => openUrl('https://base.org/builders/minikit')}
    >
    BUILT ON BASE WITH MINIKIT
  </button>
</footer>

Now that we've reviewed the MiniKit teamplate and the functionality already implemented, lets add some additional MiniKit features.

Additional MiniKit Features

Now, let's implement additional hooks provided by the MiniKit library. We'll add these features one by one.

useClose

First, let's add the ability to close the frame from within the interface:

// Add useClose to the import list
import { useMinikit, useAddFrame, useOpenUrl, useClose } from '@coinbase/onchainkit/minikit'
 
// Add the hook
const close = useClose()
 
// Add the button in the header right after the `saveFrameButton`
<div className="pr-1 justify-end">
  {saveFrameButton}
  <button
    type="button"
    className="cursor-pointer bg-transparent font-semibold text-sm pl-2""
    onClick={close}
    >
    CLOSE
  </button>
</div>

If you reload the frame in the Warpcast dev tools preview, you'll now see the close button in the top right.

usePrimaryButton

The Primary Button is a button that always exists at the bottom of the frame. Its good for managing global state which is relevant throughout your mini app.

For the template example, we'll use the Priamry Button to Pause and Restart the game. The game state is managed within the snake.tsx component, and we can easily add the usePrimaryButton hook there since the MiniKit hooks are available throughout the app.

// add an import for usePrimaryButton
import {usePrimaryButton } from '@coinbase/onchainkit/minikit'
 
// game state already exists, so we'll leverage that below.
usePrimaryButton(
  {text: gameState == GameState.RUNNING ? 'PAUSE GAME' : 'START GAME'},
  () => {
    setGameState(gameState == GameState.RUNNING ? GameState.PAUSED : GameState.RUNNING);
  }
)

You'll notice that adding the Primary button takes up space at the bottom of the frame, which causes the "BUILT ON BASE WITH MINIKIT" button to move upwards and overlap with the contorls. We can quickly fix that by changing the text to "BUILT WITH MINIKIT" and removing the ml-4 style in the className of the <button>

useViewProfile

Now, let's add profile viewing capability. The useViewProfile hook allows you to define what profile to use by defining the user's FID, which is great for social applications. If you don't define an FID, it defaults to the client FID.

import { useViewProfile } from '@coinbase/onchainkit/minikit'
 
// Add the hook
const viewProfile = useViewProfile()
 
// Add the handler function
const handleViewProfile = () => {
  viewProfile()
}
 
// Add the button in your UI in the header after the close button
<button
  type="button"
  onClick={handleViewProfile}
  className="cursor-pointer bg-transparent font-semibold text-sm pl-2
>
  PROFILE
</button>

useNotification

One of the major benefits of mini apps is that you can send notifications to your users through their socail app.

Recall the token and url we saved in the useAddFrame section? We'll use those now to send a user a notification. In this guide, we'll simply send a test notification unrelated to the game activity.

//add useNotification to the import list
import {..., useNotification } from '@coinbase/onchainkit/minikit'
 
// Add the hook
const sendNotification = useNotification()
 
// Add the handler function
const handleSendNotification = async () => {
  try {
    await sendNotification({
      title: 'New High Score! 🎉',
      body: 'Congratulations on achieving a new high score!'
    })
    setTimeout(() => setNotificationSent(false), 30000)
  } catch (error) {
    console.error('Failed to send notification:', error)
  }
}
 
// Add the button in your UI
{context?.client.added && (
  <button
    type="button"
    onClick={handleSendNotification}
    className="cursor-pointer bg-transparent font-semibold text-sm disabled:opacity-50"
  >
    SEND NOTIFICATION
  </button>
)}

Conclusion

Congratulations, you've created your first mini app, set up the manifest, added key MiniKit hooks, and sent your users a notification! We're excited to see what you build with MiniKit!