A tool to export the snapshot of an ERC20 token at the target height.

Setup

install the curl command line tool

install python 2.7

pip install requests

Usage

Use the following command to extract the balance of all the ERC20 token holders. config_file_path points to the config file (see examples below). target_height is the height to export the snapshot. The result will be written into the file specified by balance_file_path.

python run.py <config_file_path> <target_height> <balance_file_path>

Examples

Here is an example of the config file config.json. The fields are self-explanatory. For example, genesis_height is the height (i.e. block number) of the block that contains the genesis transaction of the ERC20 smart contract.

{
  "ethereum_rpc_url" : "http://localhost:8545",
  "smart_contract_address" : "0x3883f5e181fccaf8410fa61e12b59bad963fb645",
  "genesis_height" : 4728491,
  "expected_total_supply" : 1000000000000000000000000000
}

On a machine with a fully-synced Geth node, run the following command to extract the balance of all the ERC20 token holders at block height 6958428, and save the result to ./balance.json

python run.py config.json 6958428 balance.json

Note 1: On an Ethereum node that does not keep the entire history trie, we need to supply with the latest block height (can get from etherscan.io). Otherwise the script might error out.

Note 2: Before running the script, it is better to restart the Ethereum node to reclaim some memory. Otherwise the script might stuck as the Ethereum node could consume all of the available memory during the sanpshot export.