Miden ⇄ EVM Epoch Integration Example

Reference dapp showing how to use @epoch-protocol/epoch-intents-sdk to move value between an EVM chain (Sepolia) and Miden testnet via Epoch intents.

Two flows:

• Cross-chain — EVM → Miden. Pay USDC on Sepolia, receive the target asset (P2IDE note) on Miden.
• Withdraw — Miden → EVM. Burn a Miden note, receive the corresponding asset on Sepolia.

Stack

• React 19 + Vite + TypeScript + Tailwind v4
• EVM: wagmi + RainbowKit + viem
• Miden: @miden-sdk/miden-sdk, @miden-sdk/miden-wallet-adapter-react
• Intents: @epoch-protocol/epoch-intents-sdk against the Epoch testnet allocator

Run Locally

1. Copy env file:

   cp .env.example .env

   .env:

   VITE_ALLOCATOR_URL=https://testnet-dev.epochprotocol.xyz
   

2. Install + start:

   pnpm i
   pnpm run dev

3. Open http://localhost:5173.

Wallets

• EVM: any RainbowKit-supported wallet (MetaMask etc.) on Sepolia. Pays gas + provides USDC for cross-chain deposits.
• Miden: Miden wallet adapter. Required for Withdraw and for creating P2IDE notes in Cross-chain.

Test Funds

• Miden testnet tokens: claim from official Miden faucet in Miden Wallet.
• Sepolia USDC: ping Epoch team with your Ethereum address; team will send Sepolia USDC.
• Sepolia ETH: any public Sepolia faucet for gas.

Key Files

Path	Purpose
src/services/epoch-bridge.ts	Epoch SDK wrapper (intent build / submit / poll)
src/hooks/useEpochIntent.ts	EVM→Miden intent submission flow
src/hooks/useWithdrawIntent.ts	Miden→EVM withdraw flow
src/hooks/useMidenWalletAdapter.ts	Miden wallet connect/state
src/hooks/useMidenTransfer.ts	P2IDE note creation on Miden
src/hooks/useIntentFlowStatus.ts	Intent lifecycle polling
src/constants/chains.ts	Sepolia + Miden virtual chain id (999999999)
src/config/wagmi.ts	wagmi/RainbowKit config

Notes

• MIDEN_DESTINATION_CHAIN_ID = 999999999 is the virtual chain id used as tokenOut.chainId when Miden is the intent output. Do not set this to a real EVM chain id.
• Allocator URL is configurable via VITE_ALLOCATOR_URL. Default points at Epoch testnet-dev.
• Build: pnpm build (tsc -b && vite build). Lint: pnpm lint.