QuickStart

Create your own JavaScript application on Golem
In this article, we'll show you how to launch your first JavaScript app on Golem Network from scratch in 15 minutes. The result of the application will be to run the JS file using Node JS on the provider's machine and return the result. We have divided the entire article into 5 sections:
​Preparing the environment​
​Installing yagna requestor​
​Building your first JavaScript application on Golem Network​
​Run node script on provider​
​Extend app functionality​
The first two sections are duplicated with the more elaborate ones described elsewhere in the handbook. However, the purpose of this article is not to get into the details, but to show you how to start working with Golem step by step in minutes.
If you have a development environment already configured, you can go ahead and skip the first section and move on to the next one.
If you have already installed the yaggna daemon and configured the requestor correctly, go straight to the third section.
Preparing the environment
Prerequisites
OS X 10.14+, Ubuntu 18.04 or 20.04 or Windows
Familiarity with the command line
Install Node.js version 16.19.x
In this section we will introduce how to run a Simple Node Application on Golem Network. The created project will be using a build setup based on pre-built Golem Image and allow us to run Node.js script on Provider.
Make sure you have a 16.19.x version of Node.js installed:
node --version
Installing yagna requestor
To start working with Golem network we need to install yagna daemon locally. In the simplest terms, the daemon allows you to communicate with Golem Network and perform operations on it.
Easy installation
Windows Manual installation
Unix Manual installation
Easy installation
You can install it using our helper script like this:
curl -sSf https://join.golem.network/as-requestor | bash -
You might be asked to modify your PATH afterwards.
On Windows, only the manual installation is supported.
Manual installation on Windows
Alternatively, if you can't install in easy way, you will do it manually in the following way:
1.Download the requestor package - prefixed golem-requestor - appropriate for your platform from: https://github.com/golemfactory/yagna/releases/tag/v0.12.0​
2.Unzip the archive to extract the two files: yagna.exe and gftp.exe.
3.Copy those files to C:\Windows\System32
Manual installation on Unix
Alternatively, if you can't install in easy way, you will do it manually in the following way:
1.Download the requestor package - prefixed golem-requestor - appropriate for your platform from: https://github.com/golemfactory/yagna/releases/tag/v0.12.0​
2.Unpack yagna and gftp binaries and put within somewhere in your PATH (e.g. copy them to /usr/local/bin on Unix-like systems) or add the directory you placed the binaries in to your PATH
Verify if yagna available in command line:
yagna --version
It should output: yagna 0.12.0 (37060503 2022-12-02 build #251)
Verify if gftp available in command line:
gftp --version
It should output: gftp 0.12.0 (37060503 2022-12-02 build #251)
If the above commands executed correctly, congratulations you have just installed the yagna daemon in your environment.
If you have encountered problems, or would you like to learn more details about the requestor and yagna installation, please take a look in here: How to install requestor tutorial​
Configure requestor and fund your wallet
To start using Golem Network you need a key, which will be also be the address of your wallet. For the purposes of this tutorial we are using testnet. To generate a key and fund your wallet follow these steps:
Firstly, start the daemon
To perform any operations on the Golem Network the yagna daemon must be running. To do this, open a command line window and type:
yagna service run
Important: After you launch the daemon, leave it running in the background while you proceed with the tutorial.
If you have encountered problems please take look on Run the daemon section
Secondly, generate the app key (wallet)
To use the network you must have your own unique key(wallet) for which is used for billing. To generate the key, make sure you have running yagna daemon from the previous step, leave it running in the background and in a separate command line window type in:
yagna app-key create requestor
Please, note the key down
Thirdly, get some funds
In order to be able to request tasks on Golem Network, you'll need some GLM tokens. To get some funds on testnet, type in:
yagna payment fund
Once you run the command, give some time to transfer funds to your wallet. You can verify whether you already got the funds with:
yagna payment status
If you have encountered problems, or would you like to learn more details about the funding process, please take a look in here: How to get some GLM tokens​
Building your first JavaScript app on Golem Network
Congratulations you are now ready to start building your first JavaScript app on the Golem Network.
Create a new Node project
Create a new node project by typing in the command line:
mkdir golem-tutorial-js
cd golem-tutorial-js
npm init
Create a node script that will execute task on provider
Add yajsapi to your project:
npm install yajsapi
Your first app on Golem Network
Let's create a simple code that will run a command displaying the node JS version on the provider. For this purpose we would like to call the command node -v. Let's create index.mjs file that looks like the following:
index.mjs
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import { TaskExecutor } from "yajsapi";
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​
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(async () => {
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   const executor = await TaskExecutor.create("529f7fdaf1cf46ce3126eb6bbcd3b213c314fe8fe884914f5d1106d4");
5
​
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   const taskToRunOnProvider = async (workerContext) => {
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      const commandToRunInProviderShell = "node -v";
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      const result = await workerContext.run(commandToRunInProviderShell);
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      return result.stdout;
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   }
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​
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   const taskResult = await executor.run(taskToRunOnProvider);
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   await executor.end();
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   console.log('Task result:', taskResult);
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})();
Run the app
If you have the executor ready, it's time to run the script on the Golem Network.
Setup YAGNA_APPKEY
In order for the requestor agent to connect with the yagna daemon, you need to provide it with the previously-generated app key (wallet) from step Generate the app key​
MacOS / Linux
Windows
On MacOS / Linux type in command line
export YAGNA_APPKEY=insert-your-32-char-app-key-here
On Windows type in command line
set YAGNA_APPKEY=your-32-char-app-key
If you don't remember your key(wallet) you can always check it by typing in the command line: yagna app-key list
Run your first app on Golem Network
To run your scrypt on the Golem Network simply run the command:
node index.js
Result in the command line will look like:
Let's break the code down
Since you already have a working example on the golem, I'll try to show you how the code is built.
Import TaskExecutor
After create index.mjs file in the main folder, you should import TaskExecutor from yajsapi.
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import { TaskExecutor } from "yajsapi";
After importing TaskExecutor we have to create IIAFE (Immediately Invoked Async Function Expression) in index.js body, because TaskExecutor provides async methods:
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(async () => {
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    //... Function body in here
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})();
Create TaskExecutor instance
In our body function first we have to create executor using factory method Executor.create(). As a parameter we will provide image hash with Node.js.
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const executor = await TaskExecutor.create("529f7fdaf1cf46ce3126eb6bbcd3b213c314fe8fe884914f5d1106d4");
For the testing purposes we are providing pre-built image with Node: 529f7fdaf1cf46ce3126eb6bbcd3b213c314fe8fe884914f5d1106d4
Define task to run on provider instance
As the first task we would like to see the node version that is running on the given image. For this purpose we would like to call the node -v command on the provider.
Let's first create task function that we would like to run on provider. The function named as Worker and implements Worker interface.
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const taskToRunOnProvider = async (workerContext) => {
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    // ... body of task that will be run on same provider
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}
Define commands to run in the task scope
This function gets first parameter workContext that is a WorkContext object. This object allow you set the commands that you want to run in the scope of one task on one provider. So the command we would like torun on the provider is node -v
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const commandToRunInProviderShell = "node -v";
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const result = await workerContext.run(commandToRunInProviderShell);
To access stdout on the result object, simply access the stdout property.
Run the task on Golem Network
To run above defined task taskToRunOnProvider on the Golem Network, we must pass it as a parameter of the run() method on the instance of the executor.
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await executor.run(taskToRunOnProvider);
Finish gracefully task executor
On the end you should finish working with Golem Network by calling the end() method on the running instance of executor.
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await executor.end();
Refactor of the existing code
For the purpose of understanding the work with the executor, we have divided the code into small parts, but we can write it much simpler and refactor it to this form:
index.mjs
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import { TaskExecutor } from "yajsapi";
2
​
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(async () => {
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  const executor = await TaskExecutor.create("529f7fdaf1cf46ce3126eb6bbcd3b213c314fe8fe884914f5d1106d4");
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  const result = await executor.run(async (ctx) => (await ctx.run("node -v")).stdout);
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  await executor.end();
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​
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  console.log("Task result:", result);
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})();
It looks cleaner and more simple. Isn't it?
Run node script on provider
Now that you know how to run a simple command in the provider's shell, it's time to go one step further. In this section, we will create a simple script which we will then send to the provider and execute it using Node.
Create task script
For starters, let's create a simple js file that will execute on the provider. Let's generate two random numbers and then add them and return the result of this operation.
To do this, let's create a task.js file:
task.js
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function getRandomInt(min, max) {
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    min = Math.ceil(min);
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    max = Math.floor(max);
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    return Math.floor(Math.random() * (max - min + 1) + min); 
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}
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​
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const num1 = getRandomInt(1000, 10000);
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const num2 = getRandomInt(1000, 10000);
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​
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console.log(`Sum of ${num1} and ${num2} equal to ${num1 + num2}`);
You can test your code yours machine by running:
node task.js
Extend app functionality
When we have a file with the task ready, we should modify our executor code to send it to the provider, and then execute it on the provider's machine.
Uploading file to provider machine
When you look at the interface of the WorkContext object, you will notice that there is an uploadFile() method, among others. This method is used to upload file to provider instance in a scope of single task. So in order to upload our task.js file to the provider we need to add the command:
task.js
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    await ctx.uploadFile("./task.js", "/golem/resource/task.js");
Modify code to execute uploaded JS file
The last step will be to modify the command executed on the provider node -v to a command that will execute our task.js file - node /golem/work/task.js.
Our index.js file after modifications will look as follows:
index.js
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import { TaskExecutor } from "yajsapi";
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​
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(async () => {
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  const executor = await TaskExecutor.create("529f7fdaf1cf46ce3126eb6bbcd3b213c314fe8fe884914f5d1106d4");
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  const result = await executor.run(async (ctx) => {
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      await ctx.uploadFile("./task.js", "/golem/work/task.js");
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      const result = await ctx.run("node", ["/golem/work/task.js"]);
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  });
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  await executor.end();
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​
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  console.log("Task result:", result);
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})();
Result in the command line will look like:
Summary
We tried to familiarize you with how to work with Golem Network. We hope that now you understand the basics of application development. We encourage you to continue experimenting with code. If you have any suggestions about this article, we invite you to contact us.
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Last modified 7mo ago