ethjsonrpc

Python client for Ethereum using the JSON-RPC interface

• complete: implements all 62 JSON-RPC methods
• provides a high-level interface to create contracts on the blockchain and to call contract methods

Important note

The API is not yet stable, so please use caution when upgrading.

Installation

You may need additional libraries and tools before installing ethjsonrpc. On Ubuntu 14.04:

$ sudo apt-get install python-virtualenv  # optional
$ sudo apt-get install libpython-dev
$ sudo apt-get install libssl-dev

To install ethjsonrpc:

$ pip install ethjsonrpc

Make sure to have a node running an Ethereum client (such as geth) for the library to connect to.

Example

>>> from ethjsonrpc import EthJsonRpc
>>> c = EthJsonRpc('127.0.0.1', 8545)
>>> c.net_version()
u'1'
>>> c.web3_clientVersion()
u'Geth/v1.3.3/linux/go1.5.1'
>>> c.eth_gasPrice()
50000000000
>>> c.eth_blockNumber()
828948

High-level functionality

These examples assume the following simple Solidity contract:

contract Example {

    string s;

    function set_s(string new_s) {
        s = new_s;
    }

    function get_s() returns (string) {
        return s;
    }
}

Compile it like this:

$ solc --binary stdout example.sol

Setup

>>> compiled = '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'
>>> from ethjsonrpc import EthJsonRpc
>>> c = EthJsonRpc('127.0.0.1', 8545)

Creating a contract on the blockchain

>>> # continued from above
>>> contract_tx = c.create_contract(c.eth_coinbase(), compiled, gas=300000)
>>> # wait here for the contract to be created when a new block is mined
>>> contract_addr = c.get_contract_address(contract_tx)
>>> contract_addr
u'0x24988147f2f2300450103d8c42c43182cf226857'

Calling a contract function with a transaction (storing data)

>>> # continued from above
>>> tx = c.call_with_transaction(c.eth_coinbase(), contract_addr, 'set_s(string)', ['Hello, world'])
>>> tx
u'0x15bde63d79466e3db5169a913bb2069130ca387033d2ff2e29f4dfbef1bc6e0d'

Calling a contract function on the local blockchain (reading data)

>>> # continued from above
>>> results = c.call(contract_addr, 'get_s()', [], ['string'])
>>> results
['Hello, world']

Additional examples

Please see test.py for additional examples.

Implemented JSON-RPC methods

• web3_clientVersion
• web3_sha3
• net_version
• net_listening
• net_peerCount
• eth_protocolVersion
• eth_syncing
• eth_coinbase
• eth_mining
• eth_hashrate
• eth_gasPrice
• eth_accounts
• eth_blockNumber
• eth_getBalance
• eth_getStorageAt
• eth_getTransactionCount
• eth_getBlockTransactionCountByHash
• eth_getBlockTransactionCountByNumber
• eth_getUncleCountByBlockHash
• eth_getUncleCountByBlockNumber
• eth_getCode
• eth_sign
• eth_sendTransaction
• eth_sendRawTransaction
• eth_call
• eth_estimateGas
• eth_getBlockByHash
• eth_getBlockByNumber
• eth_getTransactionByHash
• eth_getTransactionByBlockHashAndIndex
• eth_getTransactionByBlockNumberAndIndex
• eth_getTransactionReceipt
• eth_getUncleByBlockHashAndIndex
• eth_getUncleByBlockNumberAndIndex
• eth_getCompilers
• eth_compileSolidity
• eth_compileLLL
• eth_compileSerpent
• eth_newFilter
• eth_newBlockFilter
• eth_newPendingTransactionFilter
• eth_uninstallFilter
• eth_getFilterChanges
• eth_getFilterLogs
• eth_getLogs
• eth_getWork
• eth_submitWork
• eth_submitHashrate
• db_putString
• db_getString
• db_putHex
• db_getHex
• shh_version
• shh_post
• shh_newIdentity
• shh_hasIdentity
• shh_newGroup
• shh_addToGroup
• shh_newFilter
• shh_uninstallFilter
• shh_getFilterChanges
• shh_getMessages

Reference

• https://github.com/ethereum/wiki/wiki/JSON-RPC