javasdk aeternity3


With the support of the æternity crypto foundation as well as the active support within the forum and devchat we were able to develop the SDK and enhance its functionalities to interact more securely with the æternity blockchain.
The SDK empowers JavaKotlin and Scala developers to interact with the æternity blockchain.

We worked hard on improving stabilityrobustness and comfort of usage while keeping maintainability and flexibility.

The SDK realizes a generic approach to provide support for every kind of transaction type based on strongly typed models. A developer just needs to create a model for a certain transaction type and the mapping, byte transformation and interaction is executed transparently.

Supported transactions types

  • Transfer AE
    • SpendTransaction
  • ÆNS interaction
    • NameClaimTransaction
    • NamePreclaimTransaction
    • NameUpdateTransaction
    • NameRevokeTransaction
  • Oracle interaction
    • OracleRegisterTransaction
    • OracleExtendTransaction
    • OracleQueryTransaction
    • OracleRespondTransaction
  • Contract interaction
    • ContractCreateTransaction
    • ContractCallTransaction
    • Compiling of contracts
    • Encoding and decoding of data and results using the Sophia HTTP Compiler
  • Other transaction types
    • GeneralizedAccountsAttachTransaction
    • GeneralizedAccountsMetaTransaction
    • PayingForTransaction (Meta-Transactions)
  • Middleware interaction
    • Communication with the middleware to retrieve information about AENS auctions

Although we already prepared TX types to support State Channels these can NOT be handled yet using the SDK.

All methods provided by the SDK can be exectued either blocking or asynchronous depending on use case and programming style. The SDK provides methods to retrieve information about current and mined transactions and blocks as well as information concerning accounts.

Furthermore the SDK provides useful utilites to cover typical use cases

  • generate and restore of KeyPairs
  • support creation and recovery of HD-wallets
  • generate and restore of Keystores
  • automatic fee calculation for all transaction types supported by the SDK
  • unit conversion tool
  • various util libraries to encode, decode and sign

The SDK can easily be configured to support uat (testnet) or mainnet.


Detailed technical information, including samples can be found in our documentation.


With the contraect-maven-plugin we provide a tool similar to the web3j-codegen for Ethereum which makes it a piece of cake to deploy and interact with Sophia smart contracts on the æternity blockchain.


Integration in

In addition to the examples above, the Java SDK is being used to integrate æternity into Venly (formerly known as ArkaneNetwork) since early 2020!

Product: SDK
Blockchain: æternity
Technologies: Java, Gradle, Lombok
Repository: aepp-sdk-java