MiniKit Quickstart

This guide shows you how to get started with MiniKit, the easiest way to build mini apps on Base! It can also be used to update an existing 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:

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

Create a new MiniKit project using the CLI

npx create-onchain --mini

Enter your CDP Client API key when prompted

You can get a CDP API key by going to the CDP Portal and navigating API Keys → Client API Key.

Skip Mini App Account Manifest Setup

You will be asked if you’d like to set up your manifest. You can skip the manifest setup step as we’ll handle that separately once we know our project’s URL.

Navigate to your project directory and install dependencies

Terminal

cd your-project-name
npm install
npm run dev

These docs are LLM-friendly—reference llms.txt in your code editor to streamline builds and prompt smarter.

Testing Your Mini App

To test your Mini App in Farcaster, 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 Mini Apps, webhooks, and notifications. Alternatively, you can use ngrok to tunnel your localhost to a live url.

Using ngrok

To successfully test your app, you’ll need the paid version of ngrok. The free version has an approval screen which can break the frame manifest. Also the url for the free version will change every time requiring you to update the manifest each time you start a new ngrok tunnel.

Start your development server:

Terminal

npm run dev

Install and start ngrok to create a tunnel to your local server:

Terminal

# 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

Copy the HTTPS URL provided by ngrok (e.g. https://your-tunnel.ngrok.io)
Visit the Farcaster Manifest Tool
Paste your ngrok URL into “Domain” and tap Submit

Deploying to Vercel

Install Vercel CLI

npm install -g vercel

Deploy with the command

bash vercel

Set environment variables in your Vercel project settings

You can use vercel env add to set these up via CLI:

NEXT_PUBLIC_CDP_CLIENT_API_KEY (from CDP Portal)
NEXT_PUBLIC_URL (deployed app URL)
NEXT_PUBLIC_IMAGE_URL (optional)
NEXT_PUBLIC_SPLASH_IMAGE_URL (optional)
NEXT_PUBLIC_SPLASH_BACKGROUND_COLORs

You can now test your mini app:

Copy your deployed vercel URL
Visit the Farcaster Manifest Tool
Paste URL into “Domain”
Tap Submit

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 applies client safeAreaInsets to ensure your app doesn’t overlap parent application elements.

app/providers.tsx

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, eliminating 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.

app/page.tsx

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

Terminal

npx create-onchain --manifest

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 preferred wallet using the recovery phrase. You can find your recovery phrase in the Farcaster app under Settings → Advanced → Farcaster 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

string

required

Base64 encoded header from manifest generation

FARCASTER_PAYLOAD

string

required

Base64 encoded payload from manifest generation

FARCASTER_SIGNATURE

string

required

Signature from manifest generation

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

While testing your Mini App please add noIndex:true to your manifest - this is so the app is not indexed while in developement.

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.

app/page.tsx

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);
  }
};

In production, you’ll want to save the url and token associated with each user in a persistent database so that you can send them notifications over time.

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.

app/page.tsx

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 template 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:

app/page.tsx

// 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 Farcaster 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 Primary 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.

app/components/snake.tsx

// 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 controls. 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.

app/page.tsx

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 social 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.

app/page.tsx

//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>
)}

Notice that we first check if the user has added the frame to their list of mini apps before displaying the button. This is using the context object provided by useMiniKit(). If you don’t see the button to send the notification, its likely because mini app hasn’t been saved.

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!

Explore MiniKit Overview

Learn more about MiniKit features and capabilities

Social Patterns Guide

Design patterns for social mini apps

Introduction

Mini Apps

Chat Agents

Prerequisites

What is a Mini App?

Initial Setup

Testing Your Mini App

Deploying to Vercel

Exploring Built-in Features

MiniKitProvider

useMiniKit

Creating the Manifest

useAddFrame

useOpenUrl

Additional MiniKit Features

useClose

usePrimaryButton

useViewProfile

useNotification

Conclusion

Explore MiniKit Overview

Social Patterns Guide

Introduction

Mini Apps

Chat Agents

​Prerequisites

​What is a Mini App?

​Initial Setup

​Testing Your Mini App

​Deploying to Vercel

​Exploring Built-in Features

​MiniKitProvider

​useMiniKit

​Creating the Manifest

​useAddFrame

​useOpenUrl

​Additional MiniKit Features

​useClose

​usePrimaryButton

​useViewProfile

​useNotification

​Conclusion

Explore MiniKit Overview

Social Patterns Guide

Prerequisites

What is a Mini App?

Initial Setup

Testing Your Mini App

Deploying to Vercel

Exploring Built-in Features

MiniKitProvider

useMiniKit

Creating the Manifest

useAddFrame

useOpenUrl

Additional MiniKit Features

useClose

usePrimaryButton

useViewProfile

useNotification

Conclusion