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Ethers Elixir

Elixir Ethers

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Ethers is a comprehensive Web3 library for interacting with smart contracts on the Ethereum (Or any EVM based blockchain) using Elixir.

Inspired by ethers.js and web3.js, Ethers leverages Elixir's amazing meta-programming capabilities to generate Elixir modules for give smart contracts from their ABI. It also generates beautiful documentation for those modules which can further help developers.


You can install the package by adding ethers (and optionally ex_secp256k1) to the list of dependencies in your mix.exs file:

def deps do
    {:ethers, "~> 0.4.5"},
    # Uncomment next line if you want to use local signers
    # {:ex_secp256k1, "~> 0.7.2"}

The complete documentation is available on hexdocs.


To use Elixir Ethers, ensure you have a configured JSON-RPC endpoint. Configure the endpoint using the following configuration parameter.

# config.exs
config :ethers,
  rpc_client: Ethereumex.HttpClient, # Defaults to: Ethereumex.HttpClient
  keccak_module: ExKeccak, # Defaults to: ExKeccak
  json_module: Jason, # Defaults to: Jason
  secp256k1_module: ExSecp256k1, # Defaults to: ExSecp256k1
  default_signer: nil, # Defaults to: nil, see Ethers.Signer for more info
  default_signer_opts: [] # Defaults to: []

# If using Ethereumex, you can specify a default JSON-RPC server url here for all requests.
config :ethereumex, url: "[URL_HERE]"

You can use one of the RPC URLs for your chain/wallet of choice or try out one of them from

For more configuration options, refer to ethereumex.

To send transactions, you need a wallet client capable of signing transactions and exposing a JSON-RPC endpoint.


To use Elixir Ethers, you must have your contract's ABI in json format, which can be obtained from This library also contains standard contract interfaces such as ERC20, ERC721 and some more by default (refer to built-in contracts in hexdocs).

Create a module for your contract as follows:

defmodule MyERC20Token do
  use Ethers.Contract,
    abi_file: "path/to/abi.json",
    default_address: "[Contract address here (optional)]"

  # You can also add more code here in this module if you wish

Calling contract functions

After defining the module, all the functions can be called like any other Elixir module.

To fetch the results (return value(s)) of a function you can pass your function result to the function.

# Calling functions on the blockchain
iex> MyERC20Token.balance_of("0x[Address]") |>
{:ok, 654294510138460920346}

Refer to for more information.

Sending transaction

To send transaction (eth_sendTransaction) to the blockchain, you can use the Ethers.send/2 function.

Ensure that you specify a from option to inform your client which account to use as the signer:

iex> MyERC20Token.transfer("0x[Recipient]", 1000) |> Ethers.send(from: "0x[Sender]")
{:ok, "0xf313ff7ff54c6db80ad44c3ad58f72ff0fea7ce88e5e9304991ebd35a6e76000"}

Refer to Ethers.send/2 for more information.

Getting Logs (Events)

Ethers provides functionality for creating event filters and fetching related events from the blockchain. Each contract generated by Ethers also will have EventFilters module (e.g. MyERC20Token.EventFilters) that can be used to create filters for events.

To create an event filter and then use Ethers.get_logs/2 function like the below example.

# Create The Event Filter
# (`nil` can be used for a parameter in EventFilters functions to indicate no filtering)
iex> filter = MyERC20Token.EventFilters.transfer("0x[From Address Here]", nil)

# Then you can simply list the logs using `Ethers.get_logs/2`

iex> Ethers.get_logs(filter)
     address: "0x5883c66ca442461d406f330775d42954bfcf7d92",
     block_hash: "0x83de67fd285067b838790406ea68f21a3afbc0ade534047725b5ccfb904c9ed3",
     block_number: 17077047,
     topics: ["Transfer(address,address,uint256)",
     topics_raw: ["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
     transaction_hash: "0xaa6fb2e1bbb27f667e76b03e8cde23db694207e06b9aa810d4c20c1f109a58e5",
     transaction_index: 0,
     data: [761112156078097834180608],
     log_index: 0,
     removed: false

Resolving Ethereum names (ENS domains) using Ethers

To resolve ENS or any other name service provider (which are ENS compatible) in the blockchain you can simply use Ethers.NameService module.

iex> Ethers.NameService.resolve("vitalik.eth")
{:ok, "0xd8da6bf26964af9d7eed9e03e53415d37aa96045"}

Built-in contract interfaces in Ethers

Ethers already includes some of the well-known contract interface standards for you to use. Here is a list of them.

  • ERC20 - The well know fungible token standard
  • ERC165 - Standard Interface detection
  • ERC721 - Non-Fungible tokens (NFTs) standard
  • ERC777 - Improved fungible token standard
  • ERC1155 - Multi-Token standard (Fungible, Non-Fungible or Semi-Fungible)
  • Multicall - Multicall3

To use them you just need to specify the target contract address (:to option) of your token and call the functions. Example:

iex> tx_data = Ethers.Contracts.ERC20.balance_of("0x[Holder Address]")
  function balanceOf(
    address _owner "0x[Holder Address]"
  ) view returns (
    uint256 balance

iex>, to: "0x[Token Address]")
{:ok, 123456}


For a detailed documentation visit Ethers hexdocs page.

Generated documentation for functions and event filters

Ethers generates documentation for all the functions and event filters based on the ABI data. To get the documentation you can either use the h/1 IEx helper function or generate HTML/epub docs using ExDoc.

Get the documentation of a contract function

iex(3)> h MyERC20Token.balance_of

                             def balance_of(owner)

  @spec balance_of(Ethers.Types.t_address()) :: Ethers.TxData.t()

Prepares balanceOf(address _owner) call parameters on the contract.

This function should only be called for result and never in a transaction on
its own. (Use

State mutability: view

## Function Parameter Types

   _owner: `:address`

## Return Types (when called with ``)

   balance: {:uint, 256}

Inspecting TxData and EventFilter structs

One cool and potentially useful feature of Ethers is how you can inspect the call

Get the documentation of a event filter

iex(4)> h MyERC20Token.EventFilters.transfer

                             def transfer(from, to)

  @spec transfer(Ethers.Types.t_address(), Ethers.Types.t_address()) ::

Create event filter for Transfer(address from, address to, uint256 value)

For each indexed parameter you can either pass in the value you want to filter
or nil if you don't want to filter.

## Parameter Types (Event indexed topics)

   from: :address
   to: :address

## Event `data` Types (when called with `Ethers.get_logs/2`)

These are non-indexed topics (often referred to as data) of the event log.

   value: {:uint, 256}

Signing Transactions

By default, Ethers will rely on the default blockchain endpoint to handle the signing (using eth_sendTransaction RPC function). Obviously public endpoints cannot help you with signing the transactions since they do not hold your private keys.

To sign transactions on Ethers, You can specify a signer module when sending/signing transactions. A signer module is a module which implements the Ethers.Signer behaviour.

Ethers has these built-in signers to use:

For more information on signers, visit hexdocs.


MyERC20Token.transfer("0x[Recipient]", 1000)
|> Ethers.send(
  from: "0x[Sender]",
  signer: Ethers.Signer.Local,
  signer_opts: [private_key: "0x..."]


All contributions are very welcome (as simple as fixing typos). Please feel free to open issues and push Pull Requests. Just remember to be respectful to everyone!

To run the tests locally, follow below steps:

brew install ethereum
npm install -g solc
  • Run ganache. After installing ganache, just run the following in a new window
> ganache --wallet.deterministic

Then you should be able to run tests through mix test.


Ethers was possible to make thanks to the great contributors of the following libraries.

And also all the people who contributed to this project in any ways.


Apache License 2.0