as-types - v2.0.0


MassaLabs as-types library.

This library provides useful AssemblyScript objects and functions to help you deal with types:

  • Amount object to safely express amounts in every currency

  • Args object to serialize assembly script native types into bytes

  • Currency object to represent monetary units used to express a value

  • Result object which represents wrapper for a value that can be either a success or an error

  • Serializable an interface that allows you to use Args to serialize/de-serialize your objects

  • SafeMath a module to avoid overflows and divisions by zero while doing operations

  • Serialization and Deserialization methods for arrays, staticArrays, booleans, strings and numbers

The complete documentation of all available functions and objects is here:


Non-secure random functions are used here.

Using non-secure random functions is the only way to have onchain randomness but these functions do not generate truly random values, making it easier for attackers to predict the output and exploit weaknesses in your smart contract.


Packages are independant you can choose to install what you need

npm i --save-dev @massalabs/as-types


After installing as-types, you can import the object classes and functions that you need in your AssemblyScript file.

One way to use the "args" object is by importing and utilizing it in the following manner:

import { Args, i32ToBytes } from  '@massalabs/as-types';

// This main function is called automatically when the smart contract is executed by the blockchain.
//the argument args contains the serialized values n and k as i32
export function sum(binaryArgs: StaticArray<u8>): StaticArray<u8>{
const args = new Args(binaryArgs);
const a = args.nextI32();
const b = args.nextI32();
return i32ToBytes(a + b)


We welcome contributions from the community!

If you would like to contribute to Massa-as-sdk, please read the CONTRIBUTING file.


as-types is released under the MIT License.

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