prover

Lodestar Prover

This package is part of ChainSafe's Lodestar project

A set of tools allowing to verify EL client JSON-RPC calls.

Usage

You can use the @lodestar/prover in two ways, as a Web3 Provider and as proxy. For prover use case see below example.

import Web3 from "web3";
import {createVerifiedExecutionProvider, LCTransport} from "@lodestar/prover";

const httpProvider = new Web3.providers.HttpProvider("https://lodestar-sepoliarpc.chainsafe.io");

const {provider, proofProvider} = createVerifiedExecutionProvider(httpProvider, {
  transport: LCTransport.Rest,
  urls: ["https://lodestar-sepolia.chainsafe.io"],
  network: "sepolia",
  wsCheckpoint: "trusted-checkpoint",
});

const web3 = new Web3(provider);

const address = "0xf97e180c050e5Ab072211Ad2C213Eb5AEE4DF134";
const balance = await web3.eth.getBalance(address, "latest");
console.log({balance, address});

In this scenario the actual provider is mutated to handle the RPC requests and verify those. So here if you use provider or httpProvider both are the same objects. This behavior is useful when you already have an application and usage of any provider across the code space and don't want to change the code. So you mutate the provider during startup.

For some scenarios when you don't want to mutate the provider you can pass an option mutateProvider as false. In this scenario the object httpProvider is not mutated and you get a new object provider. This is useful when your provider object does not allow mutation, e.g. Metamask provider accessible through window.ethereum. If not provided mutateProvider is considered as true by default. In coming releases we will switch its default behavior to false.

import Web3 from "web3";
import {createVerifiedExecutionProvider, LCTransport} from "@lodestar/prover";

const httpProvider = new Web3.providers.HttpProvider("https://lodestar-sepoliarpc.chainsafe.io");

const {provider, proofProvider} = createVerifiedExecutionProvider(httpProvider, {
  transport: LCTransport.Rest,
  urls: ["https://lodestar-sepolia.chainsafe.io"],
  network: "sepolia",
  wsCheckpoint: "trusted-checkpoint",
  mutateProvider: false,
});

const web3 = new Web3(provider);

const address = "0xf97e180c050e5Ab072211Ad2C213Eb5AEE4DF134";
const balance = await web3.eth.getBalance(address, "latest");
console.log({balance, address});

You can also invoke the package as binary.

npm i -g @lodestar/prover

lodestar-prover proxy \
  --network sepolia \
  --executionRpcUrl https://lodestar-sepoliarpc.chainsafe.io \
  --beaconUrls https://lodestar-sepolia.chainsafe.io \
  --port 8080

How to detect a web3 provider

There can be different implementations of the web3 providers and each can handle the RPC request differently. We call those different provider types. We had provided builtin support for common providers e.g. web3.js, ethers or any eip1193 compatible providers. We inspect given provider instance at runtime to detect the correct provider type.

If your project is using some provider type which is not among above list, you have the option to register a custom provider type with the createVerifiedExecutionProvider with the option providerTypes which will be an array of your supported provider types. Your custom provider types will have higher priority than default provider types. Please see existing provide types implementations to know how to implement your own if needed.

Supported Web3 Methods

✅ - Completed

⌛ - Todo

➡️ - Request will be forward to EL without any intermediary manipulations. You can limit these by providing unverifiedWhitelist option for provider or --unverifiedWhitelist from the cli. If not set then all methods will be forwarded.

❇️ - Always forwarded to EL.

Group	Method	Status	Version
Block	eth_getBlockByHash	✅	v0
	eth_getBlockByNumber	✅	v0
	eth_getBlockTransactionCountByHash	⌛	v2
	eth_getBlockTransactionCountByNumber	⌛	v2
	eth_getUncleCountByBlockHash	⌛	v2
	eth_getUncleCountByBlockNumber	⌛	v2
Chain/Network	eth_chainId	➡️
	eth_syncing	⌛	v1
	eth_coinbase	⌛	v2
	eth_accounts	➡️
	eth_blockNumber	➡️
Call and Estimate	eth_call	✅	v0
	eth_estimateGas	✅	v0
	eth_createAccessList	⌛	v2
	eth_gasPrice	⌛	v1
	eth_maxPriorityFeePerGas	⌛	v1
	eth_feeHistory	⌛	v2
Filters	eth_newFilter	⌛	v2
	eth_newBlockFilter	⌛	v2
	eth_newPendingTransactionFilter	⌛	v2
	eth_uninstallFilter	⌛	v2
	eth_getFilterChanges	⌛	v2
	eth_getFilterLogs	⌛	v2
	eth_getLogs	⌛	v1
Mining	eth_mining	➡️
	eth_hashrate	➡️
	eth_getWork	➡️
	eth_submitWork	➡️
	eth_submitHashrate	➡️
Signing	eth_sign	➡️
	eth_signTransaction	➡️
State	eth_getBalance	✅	v0
	eth_getStorageAt	⌛	v1
	eth_getTransactionCount	⌛	v2
	eth_getCode	✅	v0
	eth_getProof	❇️	v0
Transactions	eth_sendTransaction	➡️
	eth_sendRawTransaction	➡️
	eth_getTransactionByHash	⌛	v2
	eth_getTransactionByBlockHashAndIndex	⌛	v2
	eth_getTransactionByBlockNumberAndIndex	⌛	v2
	eth_getTransactionReceipt	⌛	v2
Events	eth_subscribe	❇️	v0
	eth_unsubscribe	❇️	v0

Non-supported features

• Currently does not support batch requests.

Warnings

• To use this prover the ethereum provider must support the eth_getProof method. Unfortunately, Infura does not currently support this endpoint. As an alternative, we suggest using Alchemy.

Prerequisites

• NodeJS (LTS)
• Yarn

What you need

You will need to go over the specification. You will also need to have a basic understanding of lightclient.

Getting started

• Follow the installation guide to install Lodestar.
• Quickly try out the whole stack by starting a local testnet.

Contributors

Read our contributors document, submit an issue or talk to us on our discord!

License

Apache-2.0 ChainSafe Systems