Web3

A Elixir library for interacting with Ethereum, inspired by web3.py. It’s a high level, user-friendly ethereum client.

Provides support for:

• Multiple chain HTTP RPC API
• Dynamic && Compiled SmartContract call and transaction

Example

# Defining the component
defmodule MyApp.EthMainnet do
  use Web3, rpc_endpoint: "<PATH_TO_RPC_ENDPOINT>"

  # middleware (optional)
  middleware MyApp.Middleware.Logger

  # dispatch (optional)
  dispatch :eth_getBalance, args: 2

  # contract (optinnal)
  contract :FirstContract, contract_address: "0xdAC17F958D2ee523a2206206994597C13D831ec7", abi_path: "path_to_abi.json"
end

# (Optional) If you need to customise your middleware.
defmodule MyApp.Middleware.Logger do
  @moduledoc false

  @behaviour Web3.Middleware

  require Logger
  alias Web3.Middleware.Pipeline
  import Pipeline

  @doc "Before Request HTTP JSON RPC"
  def before_dispatch(%Pipeline{} = pipeline) do
    # Set metadata assigns here.
    Logger.info("MyApp before_dispatch")
    pipeline
  end

  @doc "After Request HTTP JSON RPC"
  def after_dispatch(%Pipeline{} = pipeline) do
    Logger.info("MyApp after_dispatch")
    pipeline
  end

  @doc "When after request HTTP JSON RPC failed"
  def after_failure(%Pipeline{} = pipeline) do
    Logger.info("MyApp after_failure")
    pipeline
  end
end

# Get latest block number
iex> MyApp.EthMainnet.eth_blockNumber
{:ok, 15034908}

# Get address balance.
iex> MyApp.EthMainnet.eth_getBalance("0xF4986360a6d873ea02F79eC3913be6845e0308A4", "latest")
{:ok, 0}

# Get multi-addresses balance.
iex> MyApp.EthMainnet.eth_getBalance(["0xF4986360a6d873ea02F79eC3913be6845e0308A4", "0xF4986360a6d873ea02F79eC3913be6845e0308A4"], "latest")
{:ok,
  %{
    errors: [],
    params_list: [
      {"0xF4986360a6d873ea02F79eC3913be6845e0308A4", 0},
      {"0xF4986360a6d873ea02F79eC3913be6845e0308A4", 0}
    ]
  }
}

# Query Contract
iex> MyApp.EthMainnet.FirstContract.balanceOf_address_("0xF4986360a6d873ea02F79eC3913be6845e0308A4")
{:ok, 0}

# Make Transaction
iex> MyApp.EthMainnet.FirstContract.approve_address_uint256_(
  "0x0000000000000000000000000000000000000000", 
  10, 
  gas_price: 12_000_000_000, 
  gas_limit: 300_000, 
  chain_id: 1, 
  nonce: 1
)

{:ok, true}

Overview

• Getting started
• ETH API
• SmartContract
• Middleware
• Variables
• Base API
• Examples
• Used in production?

Used in production?

Web3 is under development and is not recommended for use in production environments

Contributing

Bug report or pull request are welcome.

Make a pull request

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Please write unit test with your code if necessary.

License

web3 is available as open source under the terms of the MIT License.