Feature: Support Mini Apps

[hellno]

Summary

Add support for Farcaster Mini Apps in herocast, allowing users to discover, interact with, and launch mini apps directly within the client.

Background

Mini Apps are interactive applications built on Farcaster that provide rich, app-like experiences within the social feed. Supporting mini apps would bring herocast to parity with other Farcaster clients and give power users access to the growing mini app ecosystem.

Proposed Features

• Render mini app embeds in the feed
• Mini app launcher/discovery interface
• Wallet provider integration for transactions and signatures
• Manifest verification and app metadata display
• Notification handling (optional)
• Bookmark/favorite mini apps for quick access

Technical Requirements

Core Host Responsibilities

1. SDK Communication - JavaScript postMessage channel for iframe communication
2. Splash Screen - Display branded splash until app calls sdk.actions.ready()
3. Header Display - Show app name/author from manifest above the mini app
4. Viewport - Render in vertical modal at 424x695px on web
5. Manifest Verification - Fetch and validate /.well-known/farcaster.json from each app's domain

Wallet Provider Integration

Mini apps access wallets via the SDK:

const ethProvider = sdk.wallet.getEthereumProvider() // EIP-1193 compatible
const solProvider = sdk.wallet.getSolanaProvider()   // Wallet Standard compatible

Approach Options:

Approach	Pros	Cons
Pass-through to browser wallet	Native UX, user keeps existing wallet	Cross-origin iframe security complexity
Herocast as wallet proxy	Unified experience, controlled signing flow	Additional implementation overhead
WalletConnect bridge	Works with mobile/external wallets	Extra connection step for users

Relevant Packages

Package	Purpose
@farcaster/miniapp-host	Web host implementation
@farcaster/miniapp-sdk	SDK used by mini apps
@farcaster/miniapp-node	Backend webhook verification

Resources

• Mini Apps Documentation
• Mini Apps Full Specification (LLM-friendly)
• Specification Details
• Source Code