ETH/RPC Gateway launcher CLI

A command-line tool to launch RPC gateways for Ethereum-compatible chains using preconfigured or custom ETH/RPC endopoints, with support for both read-only interactions and transaction signing using private keys set up locally on the user's development environment.

This utility provides a quick and consistent way to interact with multiple EVM networks from the command line, ideal for scripting, diagnostics, network health checks, and automated transactions.

🧭 Overview

The ETH/RPC Gateway launcher CLI allows you to:

• 🚀 Launch a local JSON-RPC proxy or relay to a remote ETH/RPC provider.
• 🌐 Target multiple EVM-compatible L1 & L2 networks (Ethereum, Polygon, Arbitrum, etc.).
• ⚙️ Use preconfigured endpoints or provide your own.
• 📊 Inspect basic chain info directly from the terminal.
• ✍️ Sign transactions with private keys from your local environment.
• 🔄 Support for ecosystems where RPC providers do not comply with the standard Ethereum JSON-RPC protocol, such as: Conflux Core, Reef, TEN and zkSync.

This makes the gateway a flexible and pretty convenient tool, even for non-standard Ethereum-compatible chains and environments.

📦 Installation

npm install -g ethrpc-gateway

or using yarn:

yarn global add ethrpc-gateway

🛠️ Usage

• General usage:

ethrpc [<ECOSYSTEM>[:<NETWORK>] [<PORT> [<REMOTE_PROVIDER_URL]]

Listing supported networks:

• List supported EVM-compatible ecosystems:

ethrpc

• List supported networks within the specified ecosystem (e.g. Polygon):

ethrpc polygon

Launching a read-only gateway:

• Launch a gateway with the specified network and port (e.g. Ethereum Sepolia):

ethrpc ethereum:sepolia 7777

Launching a gateway with signing capability:

• Launch a gateway with the specified network and private keys (e.g. Conflux Core Testnet):

export ETHRPC_PRIVATE_KEYS=["your_private_key_1", ..., "your_private_key_n", ]
ethrpc conflux:core:testnet

• Launch a gateway with the specified network and remote provider (e.g. Ethereum Mainnet):

export ETHRPC_SEED_PHRASE="your seed phrase here"
export ETHRPC_PROVIDER_URL=https://mainnet.infura.io/v3/you_infura_key_here
ethrpc ethereum:mainnet

🌍 Supported Chains

Testnets (36)

| Ecosystem | Network Name | Default Port | Chain Id | | :-------- | :--------------------- | :----------: | -------: | | Arbitrum | arbitrum:sepolia | 8517 | 421614 | Avalance | avalanche:testnet | 8533 | 43113 | BASE | base:sepolia | 8502 | 84532 | BOBA | boba:bnb:testnet | 8510 | 9728 | | boba:eth:goerli | 8515 | 2888 | CELO | celo:sepolia | 8538 | 11142220 | Conflux | conflux:core:testnet | 8540 | 1 | | conflux:espace:testnet | 8529 | 71 | Cronos | cronos:testnet | 8530 | 338 | Dogechain | dogechain:testnet | 8519 | 568 | Elastos | elastos:testnet | 8513 | 21 | Ethereum | ethereum:sepolia | 8506 | 11155111 | Fuse | fuse:testnet | 8511 | 123 | Gnosis | gnosis:testnet | 8509 | 10200 | KAVA | kava:testnet | 8526 | 2221 | KCC | kcc:testnet | 8537 | 322 | KAIA | kaia:testnet | 8527 | 1001 | Mantle | mantle:sepolia | 8508 | 5003 | Meter | meter:testnet | 8523 | 83 | Metis | metis:sepolia | 8536 | 59902 | Moonbeam | moonbeam:moonbase | 8531 | 1287 | | moonbeam:moonriver | 7531 | 1285 | OKC | okx:oktchain:testnet | 8528 | 65 | | okx:xlayer:sepolia | 8505 | 195 | Optimism | optimism:sepolia | 8503 | 11155420 | Polygon | polygon:amoy | 8535 | 80002 | | polygon:zkevm:testnet | 8512 | 1442 | Reef | reef:testnet | 8532 | 13939 | Scroll | scroll:sepolia | 8514 | 534351 | Syscoin | syscoin:testnet | 8521 | 5700 | | syscoin:rollux:testnet | 8507 | 57000 | TEN | ten:testnet | 8504 | 443 | Ultron | ultron:testnet | 8516 | 1230 | Unichain | unichain:sepolia | 8500 | 1301 | World | worldchain:sepolia | 8501 | 4801 | ZkSync | zksync:sepolia | 8499 | 300

Mainnets (28)

| Ecosystem | Network Name | Default Port | Chain Id | | :-------- | :--------------------- | :----------: | -------: | | Arbitrum | arbitrum:mainnet | 9517 | 42161 | Avalance | avalanche:mainnet | 9533 | 43114 | BASE | base:mainnet | 9502 | 8453 | BOBA | boba:bnb:mainnet | 9510 | 56288 | | boba:eth:mainnet | 9539 | 288 | CELO | celo:mainnet | 9538 | 42220 | Conflux | conflux:core:mainnet | 9540 | 1029 | | conflux:espace:mainnet | 9529 | 1030 | Cronos | cronos:mainnet | 9530 | 25 | Dogechain | dogechain:mainnet | 9519 | 2000 | Elastos | elastos:mainnet | 9513 | 20 | Ethereum | ethereum:mainnet | 9545 | 1 | Gnosis | gnosis:mainnet | 9509 | 100 | KAVA | kava:mainnet | 9526 | 2222 | KCC | kcc:mainnet | 9537 | 321 | KAIA | kaia:mainnet | 9527 | 8217 | Mantle | mantle:mainnet | 9508 | 5000 | Meter | meter:mainnet | 9523 | 82 | Metis | metis:sepolia | 7536 | 1088 | Moonbeam | moonbeam:mainnet | 9531 | 1284 | Optimism | optimism:mainnet | 9520 | 10 | Polygon | polygon:mainnet | 9535 | 137 | | polygon:zkevm:mainnet | 9512 | 1101 | Reef | reef:mainnet | 9532 | 13939 | Scroll | scroll:mainnet | 9514 | 534352 | Syscoin | syscoin:testnet | 9521 | 57 | Ultron | ultron:mainnet | 9516 | 1231 | World | worldchain:mainnet | 9501 | 480

🧱 Built With

• Node.js
• Axios
• Ethers v5
• js-conflux-sdk
• zksync-ethers
• @reef-defi/evm-provider

🔒 Security Notice

• This tool does read private keys from system environment variables, but not does it read nor store them on disk.
• Private keys are used only in memory to sign transactions.
• You must set either the ETHRPC_PRIVATE_KEYS or the ETHRPC_SEED_PHRASE environment variables, or provide your private keys via a secure method during development.

Warning: Never expose private keys in production environments. This tool is meant for development or testing use.

📜 License

MIT © 2025 — Maintained by the Witnet Project.

🤝 Contributing

PRs are welcome! If you'd like to add new features or extend support to more networks, feel free to open an issue or submit a pull request.