This project is now a part of Hyperledger Quilt.

Thanks to all of the core contributors that got this work to this point:

Interledger Core (Java) join the chat on gitter circle-ci codecov

Base library for Interledger projects providing service interfaces, event descriptions, exceptions and data models.

For more information about Interledger specifications that underpin this library, please reference https://github.com/interledger/rfcs.


For more detail about how to use this library, consult the wiki

The library offers interfaces for all core objects and default builders that produce immutable instances of these objects.

The library also offers a codecs for encoding and decoding the objects according to the ASN.1 specifications and OER (Octet encoding rules).

Interledger Address

Interledger Addresses can be created from a String and then manipulated using utility functions

//Create a new address (short form)
InterledgerAddress address = InterledgerAddress.of("private.bob");

//Create a new address (long form)
InterledgerAddress destinationAddress = InterledgerAddress.builder()

//Check if an address starts with a specific prefix
if( address.startsWith("test") ) {
  //Testnet address...

Conditions and Fulfillments

Conditions can be derived from a fullfillment or directly from the underlying hash

//Create a fulfillment from a pre-image of 32-bytes (short form)
Fulfillment fulfillment = Fulfillment.of(preimage);

//Create a fulfillment from a pre-image of 32-bytes (long form)
Fulfillment fulfillment = Fulfillment.builder()

//Get Condition from Fulfillment
Condition condition = fulfillment.getCondition();

//Create Condition (short form)
Condition condition1 = Condition.of(hash);

//Create Condition (long form)
Condition condition1 = Condition.builder()

Interledger Payment packet

// Build ILP Payment Packet
InterledgerPayment payment = InterledgerPayment.builder()

Interledger Payment Request

InterledgerPaymentRequest ipr = InterledgerPaymentRequest.builder()

Pre-Shared Key protocol

The PSK protocol defines an envelope format for the data in an ILP Payment packet but also a number of algorithms for deriving various keys and secrets based on a single receiver secret.

The PSK Context is created using the receiver secret (on the receiver side) or just the shared key on the sender side. A sender side context cannot be used to derive a receiverId and has no random token so calling either getToken() or getReceiverId() will throw.

See ILP-RFC 16 for more details of PSK

// Create a new context at the receiver and seed with a new random token
PskContext context = PskContext.seed(SECRET);

//Load a context from an incoming payment using the token extracted from the destination address
in the payment
PskContext receiverContext =
    PskContext.fromReceiverAddress(SECRET, incomingPayment.getDestinationAccount());

//Load a context from the shared key provided to the sender during the SPSP exchange
PskContext senderPskContext = PskContext.fromPreSharedKey(psk);

//Create a PSK Message
PskMessage pskMessage = PskMessage.builder()
  .addPrivateHeader("Secret", secretStuff)

// Encrypt message
PskMessage encryptedPskMessage = context.encryptMessage(pskMessage);

// Decrypt message
PskMessage decryptedPskMessage = context.decryptMessage(encryptedPskMessage);

For a full end-to-end test demonstrating all of these functions see: org.interledger.ipr.InterledgerPaymentRequestEndToEndTest


We welcome any and all submissions, whether it's a typo, bug fix, or new feature.


This project uses Gradle to manage dependencies and other aspects of the build. To install Gradle, follow the instructions at https://gradle.org.

Get the Code

$ git clone https://github.com/interledger/java-ilp-core.git

Build the Project

To build the project, execute the following command from the top-level folder that you cloned the above two projects to. For example:

$ gradle build test


The project uses checkstyle to keep code style consistent. To run the style checks:

$ gradle build check


This project utilizes a Pull Request submission model. Before submitting a pull request, ensure that your build passes with no test failures nor Checkstyle errors.