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@akru akru released this Oct 26, 2018 · 41 commits to master since this release

This release introduce changes in account system of library. Accounts is a big deal for any crypto(currency) library. Previously hs-web3 support node managed accounts only. Currently library support three types of accounts:

  • Default account (node managed, typically first of accounts list, should be unlocked)
  • Personal account (node managed accounts available via JSON-RPC personal_* API)
  • Local account (derived from secp256k1 private key and use JSON-RPC sendRawTransaction call)

Transaction sending code have a lot of changes too. Introduced Account typeclass in Network.Ethereum.Account module that looks like:

class MonadTrans t => Account a t | t -> a where
    -- | Run computation with given account credentials
    withAccount :: JsonRpc m => a -> t m b -> m b

    -- | Send transaction to contract, like a 'write' command
    send :: (JsonRpc m, Method args) => args -> t m TxReceipt

    -- | Call constant method of contract, like a 'read' command
    call :: (JsonRpc m, Method args, AbiGet result) => args -> t m result

This is mean that sending transaction from multiple accounts simultaneously using withAccount function is not a problem now.

... = do
  withAccount () $ ...
  withAccount (Personal "0x..." "password") $ ...

Transaction parametrisation was too hard previously and forced to carry a lot of vars. Currently withParam function exported in account module use state monad for transaction parametrisation. It make code looks good and more powerful.

    withAccount () $
            -- Set transaction value
            withParam (value .~ halfBalance) $ do
                -- Send transaction to alice account
                withParam (to .~ alice) $ send ()
                -- Send transaction to bob account
                withParam (to .~ bob) $ send ()

Finally in this release contract creation is supported via using truffle generated smart contract artifacts. Example available in tests.


  • Support for Ethereum cryptography
  • Local private key transaction signer
  • Generalized JSON-RPC monad for API methods
  • Support for multiple transaction sending methods via one Account api
  • Monad based transaction sending parametrization
  • Experimental support for solidity compiler (disabled by default)
  • Support for Ethereum mainnet ENS resolver
  • Contract typeclass with api/bytecode getters
  • Contract typeclass TH generator
  • Function for creating contracts
  • Event single/multi filters
  • HexString data type
  • Personal api calls
  • Address checksum


  • package.yaml instead web3.cabal package descriptor
  • Solidity related data types and codecs moved to Data.Solidity
  • Solidity related parsers and compiler moved to Language.Solidity
  • Modules in Network.Ethereum.Web3 moved to Network.Ethereum.Api
  • fromWei/toWei from Unit typeclass now operates over Integral


  • convert function from Unit typeclass
Assets 2
May 22, 2018
Version bump
May 13, 2018
Version bump
May 1, 2018
Version bump

@akru akru released this Apr 25, 2018 · 189 commits to master since this release

This is one of the biggest releases of hs-web3. The aim of this release is make library more easy to use and understand. In this release library modules are separated for three parts: ABI operational modules, Contract abstraction and JSON-RPC generic communication interface (Web3 module).

Imports optimization is enabled for scenario:

  • if you need TH, just only import Network.Ethereum.Contract.TH module
  • in other cases use Network.Ethereum.Web3 module

For using specified JSON-RPC method make qualified imports, like

import qualified Network.Ethereum.Web3.Eth as Eth
runWeb3 Eth.accounts


  • Descriptive types for all JSON-RPC method parameters and returned values (#15).
  • Widely use of basement:Word256 type for encoding.
  • Full list of ethereum abi encoding types:
    • bool: Bool
    • int256: IntN
    • uint256: UIntN
    • string: Text
    • bytes: Bytes
    • bytes32: BytesN
    • dynamic array: []
    • static array: ListN


  • Rewriten encoding engine for best performance, it now based on cereal:Serialize instead of parsec:Parser.
  • Renamed encoding type classes and methods: ABIEncode -> ABIPut, ABIDecode -> ABIGet.
  • Encoding related modules moved to Network.Ethereum.ABI.
  • Primitive abi encoding types are moved to separated modules in Network.Ethereum.ABI.Prim.
  • Contract interation related modules moved to Network.Ethereum.Contract.
  • Ethereum node communication modules stay in Network.Ethereum.Web3.
  • JSON-RPC tiny client is independent now and can be used separately.


  • Event type class, currently TH create Data.Default instance for Filter e.
  • Custom setup for live testing (it replaced by travis script).
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