ABI Packages

Defines classes related to encoding/decoding the high-level data types serialized into transaction payload data.


ABIDecoder is a utility class for decoding transaction data as high-level ABI types. This class contains static methods for parsing transaction data.

Instantiate an ABIDecoder

First you need to create a new ABIDecoder object. ABIDecoder wraps the given data and provides methods for decoding that stream of data as primitives and objects.

ABIDecoder decoder = new ABIDecoder(Blockchain.getData());

Decode the Data

Once you have the ABIDecoder, you can decode the data by calling the corresponding methods to the data type. Within your static function, you must decode those variables in the exact same order as they are encoded. For example, if a String and an int[] are encoded into one byte array, you can decode them as the following:

public static void decodeMyData() {
    ABIDecoder decoder = new ABIDecoder(Blockchain.getData());
    String myStr = decoder.decodeOneString();
    int[] myIntArray = decoder.decodeOneIntegerArray();


ABIEncoder is utility class for AVM ABI encoding. This class provides static helpers for encoding single data elements. It is typically more appropriate to use ABIStreamingEncoder.


ABIStreamingEncoder is a utility class for AVM ABI encoding. Instances of this class are stateful, allowing several pieces of data to be serialized into the same buffer.

Instantiate an ABIStreamingEncoder

First you need to create a new ABIStreamingEncoder object. ABIStreamingEncoder will set the buffer size to 64KiB if you do the following:

ABIStreamingEncoder encoder = new ABIStreamingEncoder();

Or you can write into an existing byte array:

byte[] encodedData = new byte[100];
ABIStreamingEncoder encoder = new ABIStreamingEncoder(encodedData);

Encode the data

Once you have the ABIStreamingEncoder, you can encode multiple values by calling the corresponding methods to their types. For example, you can encode a String and an integer into one byte array using the following example. toBytes() creates and returns a byte array representing everything that has been encoded so far:

 int i = 100;
 byte[] data = encoder.encodeOneString("myString")


Identifiers of the tokens the ABI uses to describe extents of data in a serialized stream.