Here we walk through a workflow demonstrating the core apis provided by the client. These examples assume an oasis-rs service is being used.

Set the gateway

First, one must select a gateway, for example, the Oasis Gateway.

const oasis = require('@oasislabs/client');

// Create a gateway at the given url.
const gateway = new oasis.gateways.Gateway('https://gateway.devnet.oasiscloud.io')

// Connect the library to the gateway.


After connecting, one can deploy a new service.

// Service bytecode read directly from a .wasm file compiled with `oasis build`.
const bytecode = require('fs').readFileSync('/path/to/target/service/my-service.wasm');

// Service constructor args.
const arg = "this is an argument";

// Deploy it through the connected gateway.
const service = await oasis.deploy(arg, {


Alternatively, one can connect to a previously deployed Service.

// On-chain address of the service (dummy address used here);.
const address = '0x288e7e1cc60962f40d4d782950470e3705c5acf4';

// Connect to the service.
const service = await oasis.Service.at(address);


Once you’ve connected to a service, either by deploying or by connecting to an existing service, one can execute function calls on that service.

To make an rpc to a service

const returnValue = await service.myMethod();

Event Listeners

In addition to rpcs, one can register event listeners.

service.addEventListener('MyEvent', (event) => {
  // do something...

Wallets and Web3 Gateways

In the examples above, we’ve used a Gateway to pay for and sign transactions. This is useful when you want the client to operate without a wallet, but sometimes you want more control. In such cases, it’s suggested to use a wallet and web3 gateway which will allow the client to sign and send raw transactions.

const oasis = require('@oasislabs/client');

// Wallet private key.
const privateKey = '0x1ad288d73cd2fff6ecf0a5bf167f59e9944559cd70f66cb70170702a0b4f3bd5';

// Wallet for signing and paying for transactions.
const wallet = new oasis.Wallet(privateKey);

// Etheruem gateway responsible for signing transactions.
const gateway = new oasis.gateways.Web3Gateway('wss://web3.devnet.oasiscloud.io/ws', wallet);

// Configure the gateway to use.

Web3 Options

When using a wallet and web3 gateway, one can also specify the options for the transaction. This is especially useful when working with confidential services, because the gasLimit must be explicitly supplied (estimate gas isn’t provided for confidential services).

Note that the web3 options must always be the last argument given to an rpc method, after all rpc specific arguments.

  gasLimit: '0xf00000',