Migrate to a Standard Web App - Base Documentation

After April 9, 2026, the Base App treats all apps as standard web apps regardless of Farcaster manifests. Use the migration paths below to get your app working correctly in the Base App.

Using an AI coding agent? Install the Migration Skill to let your agent handle this migration automatically. Run npx skills add base/skills and ask your agent to migrate your Farcaster app to a standard web app.

What’s changing

The Base App is moving from the Farcaster mini-app spec to a single model: standard web app + wallet, powered by Base.dev.

Before	After
Farcaster manifest (`/.well-known/farcaster.json`)	App metadata on Base.dev projects. Already registered apps do not need to update metadata.
Neynar webhooks for add/remove events	Base-owned backends (Base Account / address preferences)
FID-based notifications via Neynar	Wallet-address notifications through the Notifications API
Farcaster SDK for auth and actions	wagmi + viem + Sign-In with Ethereum (SIWE)
Search and discovery via Farcaster	Base.dev app metadata + builder codes

Choose your migration path

I'm converting an app
My app has no Farcaster SDK

Let your agent handle this. Install the Migration Skill with npx skills add base/skills and ask your agent to migrate your Farcaster app to a standard web app. The skill maps deprecated SDK methods, replaces auth and wallet logic, and wires up the Base App path automatically.

Your app uses the Farcaster SDK. The migration replaces Farcaster-specific auth, identity, and actions with standard web equivalents.

Add the standard web stack

Install wagmi, viem, and React Query if you don’t have them already:

Terminal

npm install wagmi viem @tanstack/react-query @base-org/account

Create a wagmi config for Base and wrap your app with WagmiProvider and QueryClientProvider:

config.ts

import { http, createConfig, createStorage, cookieStorage } from 'wagmi';
import { base } from 'wagmi/chains';
import { baseAccount, injected } from 'wagmi/connectors';

export const config = createConfig({
  chains: [base],
  connectors: [
    injected(),
    baseAccount({
      appName: 'My App',
    }),
  ],
  storage: createStorage({ storage: cookieStorage }),
  ssr: true,
  transports: {
    [base.id]: http(),
  },
});

declare module 'wagmi' {
  interface Register {
    config: typeof config;
  }
}

App.tsx

import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
import { WagmiProvider } from 'wagmi';
import { config } from './config';

const queryClient = new QueryClient();

export default function App({ children }: { children: React.ReactNode }) {
  return (
    <WagmiProvider config={config}>
      <QueryClientProvider client={queryClient}>
        {children}
      </QueryClientProvider>
    </WagmiProvider>
  );
}

This replaces the Farcaster frame connector with standard wagmi providers that work in the Base app’s in-app browser.

Replace auth and identity

Farcaster sign-in and FID-based identity are not available in the Base App. Replace them with SIWE for authentication and the connected wallet address for user identity.Build, sign, and verify the SIWE message:

SignIn.tsx

'use client';

import { useState } from 'react';
import { createSiweMessage, generateSiweNonce } from 'viem/siwe';
import { useAccount, usePublicClient, useSignMessage } from 'wagmi';

export function SignIn() {
  const { address, chainId, isConnected } = useAccount();
  const [isSigningIn, setIsSigningIn] = useState(false);
  const { signMessageAsync } = useSignMessage();
  const publicClient = usePublicClient();

  async function handleSignIn() {
    if (!isConnected || !address || !chainId || !publicClient) {
      throw new Error('Connect your wallet before signing in');
    }

    setIsSigningIn(true);
    const nonce = generateSiweNonce();

    try {
      const message = createSiweMessage({
        address,
        chainId,
        domain: window.location.host,
        nonce,
        uri: window.location.origin,
        version: '1',
      });

      const signature = await signMessageAsync({ message });

      const valid = await publicClient.verifySiweMessage({ message, signature });
      if (!valid) throw new Error('SIWE verification failed');
    } finally {
      setIsSigningIn(false);
    }
  }

  return (
    <button
      type="button"
      onClick={handleSignIn}
      disabled={!isConnected || isSigningIn}
    >
      {isSigningIn ? 'Signing in...' : 'Sign in with Ethereum'}
    </button>
  );
}

This example verifies the signature client-side. If your app needs server-side sessions or replay protection, see the Authenticate users guide for the full pattern with server-issued nonces, backend verification.

Use useAccount from wagmi to read the connected wallet address as the user’s identity and guard SIWE execution until the wallet and chain are available.

Review SDK method compatibility

See the compatibility table for what will and won’t work in the Base app, along with standard web alternatives.

Migrate notifications to Base.dev

Farcaster-based notifications (via Neynar, FIDs, or tokens) will not reach Base App users. Follow the Notifications guide to fetch opted-in wallet addresses and send notifications through the Base Dashboard API.

If you haven’t registered yet, create a project at Base.dev and complete your app metadata: name, icon, tagline, description, screenshots, category, primary URL, and builder code. Already registered apps do not need to re-register or update metadata.

Deprecated Farcaster SDK methods in the Base App

The following Farcaster mini-app SDK methods are not invoked by the Base App after April 9, 2026. Migrate to the alternatives listed.

SDK method	Alternative in the Base App
`signIn`	Sign-In with Ethereum using wagmi (`useSignMessage`)
`sendToken`	Standard ERC-20 transfer with wagmi (`useWriteContract`)
`openUrl`	`window.open(url)`
`openMiniApp`	`window.open(url)`
`viewToken`	Deeplink: `https://base.app/coin/base-mainnet/TOKEN_ADDRESS`
`viewProfile`	Deeplink: `https://base.app/profile/WALLET_ADDRESS`
`swapToken`	Construct swap transactions with wagmi, viem, or your preferred onchain library.
`requestCameraAndMicrophoneAccess`	No replacement
`close`	No replacement
`addMiniApp`	the Base App handles app installation automatically. No SDK needed.
`viewCast`	Not needed in the Base App
`composeCast`	Not needed in the Base App
`ready`	Not needed. Your app is ready to display when it loads.
User context and FID	Read the injected wallet address via wagmi (`useAccount`)

Pre-flight checklist

Before considering your app migrated, verify the following:

Wallet and auth use wagmi + viem

Wallet connection and contract interactions use wagmi + viem. Authentication uses SIWE where needed.

Project is registered on Base.dev with primary URL set. Name, icon, tagline, screenshots, category, description, and builder code are all filled in.

Notifications use Base.dev API (if applicable)

Notifications are sent by wallet address using the Notifications guide, not through Neynar, FIDs, or tokens.

If all steps above are complete, your app is ready for the Base App as a standard web app.

​What’s changing

​Choose your migration path

​Deprecated Farcaster SDK methods in the Base App

​Pre-flight checklist

What’s changing

Choose your migration path

Deprecated Farcaster SDK methods in the Base App

Pre-flight checklist