🛠️ Introduction

Welcome to the Appic documentation! Appic is a bridging solution that connects Ethereum Virtual Machine (EVM) chains and the Internet Computer (ICP). This guide explains Appic's components and how they work together to enable secure and efficient cross-chain asset transfers.

📘 Prerequisites

Before diving in, you should know:

• Basics of the Internet Computer (ICP).
• How EVM chains work and their functionality.

🌟 Overview

Appic bridges EVM chains and ICP with three main canisters:

1. evm-minter (GitHub repository)
2. ledger-suite-manager (lsm) (GitHub repository)
3. chain-fusion-helper (GitHub repository)

These canisters work together to ensure secure and decentralized cross-chain transfers.

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🔒 evm-minter

The evm-minter enables token transfers by:

1. Locking tokens on the EVM chain.
2. Minting wrapped tokens on the ICP chain.

✨ Use Cases

1. Deposit (Lock Tokens)

• Convert native tokens (e.g., BNB) into wrapped tokens (e.g., icBNB).
• Convert ERC20 tokens (e.g., USDT) into wrapped ERC20 tokens (e.g., icUSDT).

2. Withdrawal (Unlock Tokens)

• Convert wrapped tokens (e.g., icBNB) back to native tokens (e.g., BNB).
• Convert wrapped ERC20 tokens (e.g., icUSDT) back to ERC20 tokens (e.g., USDT).

🔐 Security

The evm-minter ensures security with:

• EVM RPC canister for reliable communication.
• Threshold ECDSA signing for secure validation.

No off-chain dependencies are required, ensuring safety and efficiency. Refunds are automatically processed if transactions fail.

📄 Integration Guide

• Deposit Flow
• Withdrawal Flow

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📋 ledger-suite-manager (lsm)

The lsm canister handles:

1. Creating twin tokens on ICP for EVM tokens.
2. Managing Ledger Suites (Ledger, Index, Archive).
3. Upgrading Ledger Suites when needed.

🔧 Twin Token Creation

Developers can create wrapped ICP tokens for EVM assets supported by the evm-minter. Fees are paid in ICP or Appic tokens, and the process is fully automated.

📄 Integration Guide

• Twin Token Creation

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🔍 chain-fusion-helper

The chain-fusion-helper canister provides essential data for bridging operations.

🔑 Key Features

• Transaction Management: Collects and organizes deposit and withdrawal data.
• Query Endpoints: Retrieve bridge transaction history using wallet addresses or ICP IDs.
• Token Data:
  • Lists over 1,000 EVM tokens across major chains.
  • Provides real-time ICP token prices.
  • Shows bridgeable tokens between ICP and EVM.
  • Tracks wrapped tokens created via the lsm.

The chain-fusion-helper centralizes this information for easy access.

📄 Integration Guide

• Get Chain Fusion Data