# firefly-evmconnect

**Repository Path**: hyperledger/firefly-evmconnect

## Basic Information

- **Project Name**: firefly-evmconnect
- **Description**: Firefly EVM Connect
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2022-06-10
- **Last Updated**: 2025-08-12

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

[![codecov](https://codecov.io/gh/hyperledger/firefly-evmconnect/branch/main/graph/badge.svg?token=OEI8A08P0R)](https://codecov.io/gh/hyperledger/firefly-evmconnect)
[![Go Reference](https://pkg.go.dev/badge/github.com/hyperledger/firefly-evmconnect.svg)](https://pkg.go.dev/github.com/hyperledger/firefly-evmconnect)

# 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](https://hyperledger.github.io/firefly/latest/overview/public_vs_permissioned/#firefly-architecture-for-public-chains)
and the [FireFly Transaction Manager](https://github.com/hyperledger/firefly-transaction-manager) repository for
more information.

> Also see [firefly-ethconnect](https://github.com/hyperledger/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](https://github.com/hyperledger/firefly-signer) repository.

## Configuration

For a full list of configuration options see [config.md](./config.md)

## Example configuration

```yaml
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.