Ethereum To Conflux Relay

A bridge for protocols that can interact with Ethereum to begin interacting with Conflux without changing core code

Note: Cannot relay signed transactions from ETH to CFX, only unsigned information.

Technical Details

A relay to convert ETH JSON-RPC calls to CFX JSON-RPC calls.
Supports both HTTP and Websocket endpoints.

Project specs and notes:

• Conflux nodes use slightly different function calls that Ethereum JSON-RPC
• Using a JSON-RPC server as a relay
  • https://www.npmjs.com/package/jayson#using-the-server-as-a-relay
  • https://www.npmjs.com/package/jayson#method-routing
  • Relay converts calls to ETH calls to CFX calls (pre-processing)
  • Relay converts CFX responses to ETH responses (post-processing)

Commands

• yarn start: start up the relay
• yarn test: start tests (make sure to also start relay)

.env File Configuration:

ENDPOINT=http://test.confluxrpc.org
PORT=3000

Pre-Processing Functions

• Methods are converted from eth_* to cfx_* calls following the recommendations on the Conflux documentation.
• The ETH block parameter is converted to the CFX epoch parameter.
• Certain methods that do not have complimentary cfx_* calls are custom built in the index.js under the customMethods() function.

Post-Processing Functions

• Calls that involve getting block information (getBlockByHash, getBlockBy(Epoch)Number) have CFX parameters mapped to ETH parameters as follows: (any hard coded values do not have comparable equivalents)

  ETH parameter	CFX parameter
  sha3Uncles	keccak256(Buffer.from(refereeHashes))
  stateRoot	deferredStateRoot
  receiptsRoot	deferredReceiptsRoot
  gasUsed	0x0
  extraData	0x0 (32 bytes)
  uncles	[]
  number	height

• Calls involving transaction information (getBlockByHash, getBlockBy(Epoch)Number, getTransactionByHash) have CFX parameters mapped to ETH parameters as follows:

  ETH parameter	CFX parameter
  input	data
  blockNumber	see code for details

• Calls involving receipt data (getTransactionReceipt) have CFX parameters mapped to ETH parameters as follows:

  ETH parameter	CFX parameter
  transactionIndex	index
  cumulativeGasUsed	gasUsed
  blockNumber	epochNumber

Improvements

• What other calls need to be converted/supported?
• Not all calls have test cases written
• Remove reliance on public node endpoint

Resources

• CFX JSON-RPC - Conflux Documentation
• ETH JSON-RPC - Ethereum Documentation
• Jayson - simple JSON-RPC server