MiniKit

MiniKit is easiest way to build Mini Apps on Base, allowing developers to easily build applications without needing to know the details of the SDK implementation. It integrates seamlessly with OnchainKit components and provides Coinbase Wallet-specific hooks that degrade gracefully on other clients such as Warpcast.

Why MiniKit?

MiniKit streamlines mini-app development by providing a comprehensive toolkit that makes complex Frames SDK interactions intuitive:

Simplified Development: Build apps with minimal knowledge of the Frames SDK
Coinbase Wallet Integration: Access Coinbase Wallet-specific hooks that degrade gracefully on other clients
Component Compatibility: Use OnchainKit components out of the box with MiniKit
Automatic Setup: CLI tool for quick project scaffolding with webhooks and notifications
Account Association: Simplified generation of account associations

Use Cases

Gaming mini apps
Social mini apps
Payment mini apps
And many more possibilities!

Quick Start

The fastest way to get started with MiniKit is to use the CLI to bootstrap a new project:

npx create-onchain@alpha --mini

This command will:

Set up a new project with both frontend and backend components
Configure webhooks and notifications
Set up account association generation
Create a demo app showcasing onchain abilities using OnchainKit

After running the command, follow the prompts to configure your project.

Provider

The MiniKitProvider wraps your application and provides global access to the SDK's context. It handles initialization, events, and automatically applies client safeAreaInsets to ensure your app doesn't overlap parent application elements.

import { MiniKitProvider } from '@coinbase/onchainkit/minikit';
 
function App({ children }) {
  return (
    <MiniKitProvider
      projectId="your-project-id"
      notificationProxyUrl="/api/notification"
    >
      {children}
    </MiniKitProvider>
  );
}

Props

The MiniKitProvider accepts the following props:

export type MiniKitProviderReact = {
  children: React.ReactNode;
  notificationProxyUrl?: string;
  ...OnchainKitProviderProps
};

children: React components to be wrapped by the provider
notificationProxyUrl: Optional URL to override the default /api/notification proxy
All props from OnchainKitProvider are also supported

The provider sets up wagmi and react-query providers automatically. It configures connectors to use the Farcaster connector if sdk.context is set, with a fallback to CoinbaseWallet. This allows the same application to run both in frames and as a standalone application.

Hooks

MiniKit provides several utility hooks that wrap the SDK functionality, making it easy to access different features.

useMiniKit

This hook handles initialization of the application and provides access to the SDK context.

const { ready, isReady, context, updateClientContext, notificationProxyUrl } = useMiniKit();
 
// Call ready() when your app is ready to be shown
useEffect(() => {
  if (!isReady) {
    ready();
  }
}, [isReady, ready]);

Returns:

{
  ready: () => Promise<MiniKitContextType>; // Removes splash screen and shows the application
  isReady: boolean; // Whether the app is ready to be shown
  context: FrameContext | null; // The current frame context
  updateClientContext: (params: UpdateClientContextParams) => void; // Update client context
  notificationProxyUrl: string; // The notification proxy URL
}

useTBADeepLink

This hook wraps sdk.actions.openUrl and provides a map of all available TBA deep links. If a user is not in TBA, this hook will open an external browser and attempt to deep link to the TBA app.

const openBuyLink = useTBADeepLink('buy');
const openSwapLink = useTBADeepLink('swap');
 
// Usage
<button onClick={() => openBuyLink()}>Buy Tokens</button>
<button onClick={() => openSwapLink()}>Swap Tokens</button>

useAddFrame

This hook adds a frame to the user's list of frames and returns notification details.

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

Returns:

() => Promise<{
  url: string;
  token: string;
} | null>

useNotification

This hook allows sending notifications to users who have added your frame. It requires a token and URL, which are returned when a user adds your frame.

const sendNotification = useNotification();
 
// Usage
const handleSendNotification = () => {
  sendNotification({
    title: 'New High Score!',
    body: 'Congratulations on your new high score!'
  });
};

useOpenUrl

This hook wraps sdk.actions.openUrl and falls back to window.open when outside a frame context.

const openUrl = useOpenUrl();
 
// Usage
<button onClick={() => openUrl('https://example.com')}>Visit Website</button>

useClose

This hook wraps the sdk.actions.close functionality.

const close = useClose();
 
// Usage
<button onClick={close}>Close</button>

usePrimaryButton

This hook accepts primary button options and a callback which will be called on click.

usePrimaryButton(
  { text: 'Submit Score' },
  () => {
    // Handle button click
    submitScore();
  }
);

useViewProfile

This hook wraps sdk.actions.viewProfile, accepting an FID but falling back to the client's FID.

const viewMyProfile = useViewProfile(); // Uses client's FID
const viewUserProfile = useViewProfile(123456); // Uses specified FID
 
// Usage
<button onClick={viewMyProfile}>View My Profile</button>
<button onClick={viewUserProfile}>View User Profile</button>

useAuthenticate

This hook allows users to sign in with Farcaster. It wraps the SDK's signIn message, adding a default nonce and verification.

const { signIn } = useAuthenticate();
 
// Usage
const handleSignIn = async () => {
  const result = await signIn({
    domain: 'your-domain.com',
    siweUri: 'https://your-domain.com/login'
  });
 
  if (result) {
    // Handle successful authentication
    console.log('Authenticated:', result);
  }
};

CLI

The MiniKit CLI is the easiest way to get started. It automatically creates a sample application that integrates different parts of the SDK and some OnchainKit components.

npx create-onchain@alpha --mini

Features

The CLI creates an application with:

Frontend and Backend Integration
- Complete setup for adding frames, webhooks, and notifications
- Uses upstash/redis for data storage (compatible with Vercel)
- Requires users to sign up for an upstash/redis account and add their key and URL to the .env file
The CLI creates both frontend and backend components to support adding frames, webhooks, and notifications. While a frontend-only option was considered, the ability to add frames and handle notifications requires backend support. If you don't need these features, you can easily remove the database and related routes after project creation.
Account Association Generation
- Automatically generates valid account associations
- Configures the necessary environment variables

.well-known/farcaster.json Configuration

Sets up the required configuration file:

{
  "accountAssociation": {
    "header": "eyJmaWQiOjgxODAyNiwidHlwZSI6ImN1c3RvZHkiLCJrZXkiOiIweDU4YjU1MTNjMzk5OTYzMjU0MjMzMmU0ZTJlRDAyOThFQzFmRjE4MzEifQ",
    "payload": "eyJkb21haW4iOiI4MGI2LTI2MDAtMWYxOC0yNGM5LTYxMDUtNS0wLTQtNzA2Lm5ncm9rLWZyZWUuYXBwIn0",
    "signature": "MHhmOGQ1YzQyMmU3ZTZlMWNhMzU1ZmNmN2ZjYzFmYjMyZWRhZmEyNWU1NjJiMzlhYzE4OWNlMmM5ODU3Y2JjZWViNzlkZTk2ZjhiNTc5NzZjMDM2NzM4Y2UwYjhhOGQxZmMyZDFhYzA2NTdiZTU5N2VhZjFhZDE1ODBmMGQyYjJhODFi"
  },
  "frame": {
    "version": "next",
    "name": "MiniKit",
    "iconUrl": "https://onchainkit.xyz/favicon/48x48.png?v4-19-24",
    "splashImageUrl": "https://onchainkit.xyz/favicon/48x48.png?v4-19-24",
    "splashBackgroundColor": "#000000",
    "homeUrl": "https://your-domain.app/minikit"
  }
}

Notification Proxy
- Automatically sets up a proxy route at /api/notification
- Used by the useNotification hook when sending notifications
Webhooks
- Implements webhooks using the Farcaster key registry contract for verification
- Allows applications to respond to events such as FRAME_ADDED

Demo Application

The CLI also creates a demo snake game application that showcases:

Buttons to add the frame and connect your wallet
High score tracking with attestations using OnchainKit's <Transaction/> component
Score display using OnchainKit's <Identity/> components to resolve ENS names
Notifications for high scores (rate limited to one every 30 seconds)

Next Steps

Now that you have MiniKit set up, you can:

Explore the demo application to understand how the hooks work
Customize the application to fit your needs
Deploy your application to a hosting provider like Vercel

Enjoy building!