LightEVM

Basic implementation of the Ethereum Virtual Machine written in Python

LightEVM is aimed for advanced Ethereum users who wish to simulate transactions on Ethereum, but do not want to go through the hassle of setting up a node and writing a custom script to feed in their transaction

Getting Set Up

• LightEVM requires Python v3.9.13
• Create a virtual environment via the following:

python -m venv venv

• To activate the virtual envuronment and install all dependencies, do the following:

source venv/bin/activate
pip install -r requirements.txt

Running LightEVM

After activating the virtual environment, run the following to start an instance of LightEVM:

python main.py

Connecting to a Node

By default, LightEVM utilizes all information passed in by the user in execution.toml to create an instance of LightEVM. For variables such as the current block number or the transaction gas limit, LightEVM will be able to retrieve these values as otherwise, this would imply that the user never passed in such values in the first place.

The one area where there this does not apply is for contract data. In the case where LightEVM needs to interact with a contract whose data is not stored locally (i.e. not passed in by the user), LightEVM will attempt to make a call to the API URL designated in .env to grab the desired information. If the user does not provide an API URL and contract data needs to be grabbed externally, LightEVM will revert.

All logic that relate to the usage of API_URL can be found in state.py

Setting Up .env File

• Using template.env as a base template, set API_KEY equal to the url of an RPC node. Then rename template.env to .env so LightEVM can use said RPC node to pull necessary contract data whenever it is not stored locally
• Your .env file should look like the following:

API_URL="<INSERT API URL HERE>"

Simulating Transactions

For information regarding the semantics of execution.toml, please refer to the manual on setting up the EVM

Notes

• LightEVM does not support any transaction whose logic results in any CALL opcode being called, as support for multiple instances of the EVM is not yet supported
• Furthermore, LightEVM does not support any transactions that result in the creation of new contracts