is a typed PHP-7.1+ interface to Ethereum JSON-RPC API.
Check out the latest API documentation.
This is the important part of composer.json in Drupal Ethereum Module.
Calling Contracts
You can call (unpayed) functions in smart contracts easily.
The json file "$fileName" used is what you get when you compile a contract with Truffle.
You can also run tests at smart contracts, check out EthTestClient.
You can use Ethereum-PHP to watch changed on your smart contracts or index a Blockchain block by block. gs
See https://github.com/digitaldonkey/ethereum-php/blob/master/UsingFilters.md "UsingFilters" and ethereum-php-eventlistener.
Currently not all datatypes are supported.
This library is read-only for now. This means you can retrieve information stored in Ethereum Blockchain.
To write to the blockchain you need a to sign transactions with a private key which is not supported yet.
The API documentation is available at ethereum-php.org.
For reference see the Ethereum RPC documentation and for data encoding RLP dcumentation in Ethereum Wiki.
There is also a more readable Ethereum Frontier Guide version.