Hyperledger FireFly EVM Connector

This repo provides a reference implementation of the FireFly Connector API (FFCAPI) for EVM Based blockchains.

See the Hyperledger Firefly Documentation and the FireFly Transaction Manager repository for more information.

Also see firefly-ethconnect for the hardened connector optimized for private Ethereum sidechains, optimized for finality assured consensus algorithms and throughput.

License

Apache 2.0

ABI Encoding

A key responsibility of the FFCAPI connector is to map from developer friendly JSON inputs/outputs down to the binary encoding of the blockchain.

This repo uses the Apache 2.0 RLP encoding/decoding utilities from the firefly-signer repository.

Configuration

For a full list of configuration options see config.md

Example configuration

connectors:
- type: ethereum
  server:
    port: 5102
  ethereum:
    url: http://localhost:8545

Blockchain node compatibility

For EVM connector to function properly, you should check the blockchain node supports the following JSON-RPC Methods over HTTP:

Event tracking

• eth_blockNumber
• eth_newBlockFilter
• eth_getFilterLogs
• eth_getFilterChanges
• eth_getBlockByHash
• eth_getLogs
• eth_newFilter
• eth_uninstallFilter
• eth_getTransactionByHash
• eth_getTransactionReceipt

Query

• eth_call
• eth_getBalance
• eth_gasPrice[^1]

Transaction submission

• eth_estimateGas
• eth_sendTransaction
• eth_getTransactionCount
• eth_sendRawTransaction[^2]

[^1]: also used by Transaction submission if the handler is configured to get gas price using “connector”.

[^2]: only required by custom transaction handlers that supports pre-signing.