EVM Adapter Proxy

The EVM Adapter Proxy is a crucial component in the ICP-EVM Proxy project. It serves as a bridge between the Internet Computer Protocol (ICP) and EVM-compatible systems, enabling interoperability and data translation.

Important Considerations

This component is a proof of concept (PoC) and is not designed for production use. Its main purpose is to demonstrate the feasibility of integration between ICP and EVM-compatible systems.

DEX Client Integration

The DEX client integration in this proxy is implemented solely for demonstration and testing purposes in this PoC. It provides a simplified interface to interact with basic DEX operations.

Main Functions

1. Log Retrieval: Fetches ICRC-3 compatible logs from the Logger Canister on the Internet Computer.
2. Log Translation: Converts ICRC-3 logs into EVM-compatible event logs.
3. EVM RPC Compatibility: Exposes EVM RPC compatible methods, allowing interaction with ICP canisters using familiar Ethereum tooling.

Implementation

The EVM Adapter Proxy is implemented in Go and consists of several main components:

• A structure to hold necessary configuration and state.
• Functions to fetch logs from the Logger Canister.
• Functions to translate ICRC-3 logs to EVM-compatible logs.
• An HTTP server to handle incoming RPC requests.

Log Translation Process

The log translation process involves mapping ICRC-3 log fields to their EVM equivalents. This includes:

• Converting canister IDs to Ethereum-style addresses.
• Mapping event types to appropriate topic hashes.
• Formatting log data to match EVM expectations.

EVM RPC Compatibility

The EVM Adapter Proxy implements a subset of Ethereum JSON-RPC methods to provide compatibility with Ethereum tooling. Some key methods include:

Standard Ethereum Methods

• eth_chainId: Returns the chain ID.
• eth_blockNumber: Returns the number of the most recent block.
• eth_getBlockByNumber: Retrieves a block by its number.
• eth_getBlockByHash: Retrieves a block by its hash.
• eth_getLogs: Retrieves logs that match the specified filter criteria.
• eth_accounts: Returns a list of account addresses.
• net_version: Returns the current network version.
• net_listening: Indicates whether the client is actively listening for network connections.
• net_peerCount: Returns the number of peers currently connected to the client.
• web3_clientVersion: Returns the current client version.
• web3_sha3: Returns the Keccak-256 hash of the given input.

DEX-Specific Methods

• eth_getCurrencyPairs: Returns all available currency pairs from the DEX.
• eth_mintTokens: Creates new tokens for a specified recipient.
• eth_burnTokens: Destroys tokens from an owner's balance.

These methods allow Ethereum tools and libraries to interact with ICP canisters as if they were EVM-compatible smart contracts.

Example Usage

Standard Methods

# Get Chain ID
curl -X POST -H "Content-Type: application/json" \
--data '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}' \
http://localhost:3030/rpc/v1

# Get Latest Block
curl -X POST -H "Content-Type: application/json" \
--data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' \
http://localhost:3030/rpc/v1

DEX Methods

# Get Currency Pairs
curl -X POST -H "Content-Type: application/json" \
--data '{"jsonrpc":"2.0","method":"eth_getCurrencyPairs","params":[],"id":1}' \
http://localhost:3030/rpc/v1

# Mint Tokens
curl -X POST -H "Content-Type: application/json" \
--data '{
  "jsonrpc":"2.0",
  "method":"eth_mintTokens",
  "params":[{
    "currency": "ICP",
    "amount": "0x5f5e100",
    "recipient": "0x2vxsx-fae"
  }],
  "id":1
}' \
http://localhost:3030/rpc/v1

# Burn Tokens
curl -X POST -H "Content-Type: application/json" \
--data '{
  "jsonrpc":"2.0",
  "method":"eth_burnTokens",
  "params":[{
    "currency": "ICP",
    "amount": "0x2faf080",
    "owner": "0x2vxsx-fae"
  }],
  "id":1
}' \
http://localhost:3030/rpc/v1

Note: For this PoC, Ethereum addresses should be formatted as "0x<full_icp_principal>". For example, if your ICP principal is "2vxsx-fae", use "0x2vxsx-fae" as the Ethereum address. The proxy will simply remove the "0x" prefix to get the ICP principal.

Integration with Other Components

• Logger Canister: The EVM Adapter Proxy retrieves logs from the Logger Canister on the Internet Computer.
• DEX Canister: Provides access to DEX functionality through EVM-compatible methods.
• SubQuery Indexer: Translated logs are made available to the SubQuery Indexer for further processing and indexing.

For more details on the interaction between components, refer to the project overview and other component-specific documentation.

Technical Details

Client Generation

The proxy uses automatically generated clients for both Logger and DEX canisters. These clients are generated using the Makefile command:

# Generate both Logger and DEX clients
make generate-client

This command internally uses the goic tool to generate Go clients from the Candid interface definitions. The process is defined in Makefile.local.mk

The generated clients provide type-safe interfaces for interacting with the canisters.

Configuration

The proxy requires configuration for both Logger and DEX canister IDs in config.yaml:

icp:
  loggerCanisterId: "ydpfi-uiaaa-aaaal-qjupa-cai"
  dexCanisterId: "7eo5f-eqaaa-aaaam-adqoq-cai"
  nodeUrl: "https://ic0.app"

Development Workflow

1. After any changes to canister interfaces:

   make generate-client  # Regenerate Go clients

2. Build and run the proxy:

   make build
   ./output/poc-icp-icrc3-evm-adapter start -c config.yaml