# Fluence JS Client
[](https://www.npmjs.com/package/@fluencelabs/js-client.api)
[](https://www.npmjs.com/package/@fluencelabs/js-client.web.standalone)
This is the Javascript client for the [Fluence](https://fluence.network) network. The main role of the JS client is to connect to the Fluence Network and allow you to integrate Aqua code into your application.
## Installation
Adding the Fluence JS client for your web application is very easy.
### Browser-based Apps
1. Add a script tag with the JS Client bundle to your `index.html`. The easiest way to do this is using a CDN (like [JSDELIVR](https://www.jsdelivr.com/) or [UNPKG](https://unpkg.com/)). The script is large, thus we highly recommend to use the `async` attribute.
Here is an example using the JSDELIVR CDN:
```html
Cool App
```
If you cannot or don't want to use a CDN, feel free to get the script directly from the [npm package](https://www.npmjs.com/package/@fluencelabs/js-client.web.standalone) and host it yourself. You can find the script in the `/dist` directory of the package. (Note: this option means that developers understand what they are doing and know how to serve this file from their own web server.)
2. Install the following packages:
```
npm i @fluencelabs/js-client.api @fluencelabs/fluence-network-environment
```
3. Add the following lines at the beginning of your code:
```
import { Fluence } from "@fluencelabs/js-client.api";
import { randomKras } from '@fluencelabs/fluence-network-environment';
Fluence.connect(randomKras());
```
### Node.js Apps
**Prerequisites:**
The Fluence JS Client only supports the ESM format. This implies that a few preliminary steps are required if your project is not already using ESM:
- Add `"type": "module"` to your package.json.
- Replace `"main": "index.js"` with `"exports": "./index.js"` in your package.json.
- Remove `'use strict';` from all JavaScript files.
- Replace all `require()`/`module.export` with `import`/`export`.
- Use only full relative file paths for imports: `import x from '.';` → `import x from './index.js';`.
If you are using TypeScript:
- Make sure you are using TypeScript 4.7 or later.
- Add [`"module": "ESNext", "target": "ESNext", "moduleResolution": "nodenext"`](https://www.typescriptlang.org/tsconfig#module) to your tsconfig.json.
- Use only full relative file paths for imports: `import x from '.';` → `import x from './index.js';`.
- Remove `namespace` usage and use `export` instead.
- You must use a `.js` extension in relative imports even though you're importing `.ts` files.
**Installation:**
1. Install the following packages:
```
npm i @fluencelabs/js-client.api"@fluencelabs/js-client.node @fluencelabs/fluence-network-environment
```
2. Add the following lines at the beginning of your code:
```
import '@fluencelabs/js-client.node';
import { Fluence } from "@fluencelabs/js-client.api";
import { randomKras } from '@fluencelabs/fluence-network-environment';
Fluence.connect(randomKras());
```
## Usage in an Application
Once you've added the client, you can compile [Aqua](https://github.com/fluencelabs/aqua) and run it in your application. To compile Aqua, use [Fluence CLI](https://github.com/fluencelabs/fluence-cli).
1. Install the package:
```
npm i -D "@fluencelabs/fluence-cli"
```
2. Add a directory in your project for Aqua code, e.g., `_aqua`.
3. Put `*.aqua` files in that directory.
4. Add a directory for compiled Aqua files inside your sources. For example, if your app source is located in the `src` directory, you can create `src/_aqua`.
5. To compile Aqua code once, run `npx fluence aqua -i ./_aqua -o ./src/_aqua/`. To watch the changes and to recompile on the fly, add the `-w` flag: `npx fluence aqua -w -i ./_aqua -o ./src/_aqua/`.
**Hint**: it might be a good idea to add these scripts to your `package.json` file.
For example, you project structure could look like this:
```
┣ _aqua
┃ ┗ demo.aqua
┣ src
┃ ┣ _aqua
┃ ┃ ┗ demo.ts
┃ ┗ index.ts
┣ package-lock.json
┣ package.json
┗ tsconfig.json
```
Then, your `package.json` file should include the following lines:
```
{
...
"scripts": {
...
"aqua:compile": "fluence aqua -i ./aqua/ -o ./src/_aqua",
"aqua:watch": "fluence aqua -w -i ./aqua/ -o ./src/_aqua"
},
...
}
```
6. Now you can import and call Aqua code from your application like
this:
```
import { getRelayTime } from "./_aqua/demo";
async function buttonClick() {
const time = await getRelayTime();
alert("relay time: " + time);
}
```
## Debug
JS Client uses the [debug](https://github.com/debug-js/debug) library under the hood for logging. The log namespaces are structured on a per-component basis, following this structure:
```
fluence::trace
fluence::debug
fluence::error
```
Marine JS logs have a slightly different structure:
```
fluence:marine::trace
fluence:marine::debug
fluence:marine::info
fluence:marine::warn
fluence:marine::error
```
Each level corresponds to a logging level in Marine JS.
Star (`*`) character can be used as a wildcard to enable logs for multiple components at once. For example, `DEBUG=fluence:*` will enable logs for all components. To exclude a component, use a minus sign before the component name. For example, `DEBUG=fluence:*,-fluence:particle:*`
### Index of components:
- `particle`: everything related to particle processing queue
- `aqua`: infrastructure of aqua compiler support
- `connection`: connection layer
- `marine`: Marine JS logs
### Enabling logs in Node.js
enable logs, pass the environment variable `DEBUG` with the corresponding log level. For example:
```sh
DEBUG=fluence:* node --loader ts-node/esm ./src/index.ts
```
### Enabling logs in the browser
To enable logs, set the `localStorage.debug` variable. For example:
```
localStorage.debug = 'fluence:*'
```
**NOTE**
In Chromium-based web browsers (e.g. Brave, Chrome, and Electron), the JavaScript console will—by default—only show messages logged by debug if the "Verbose" log level is enabled.
## Development
To hack on the Fluence JS Client itself, please refer to the [development page](./DEVELOPING.md).
## Documentation
The starting point for all documentation related to Fluence is
[fluence.dev](https://fluence.dev/). We also have an active [YouTube channel](https://www.youtube.com/@fluencelabs).
## Support
Please, file an [issue](https://github.com/fluencelabs/js-client/issues) if you find a bug. You can also contact us at [Discord](https://discord.com/invite/5qSnPZKh7u) or [Telegram](https://t.me/fluence_project). We will do our best to resolve the issue ASAP.
## Contributing
Any interested person is welcome to contribute to the project. Please, make sure you read and follow some basic [rules](./CONTRIBUTING.md).
## License
All software code is copyright (c) Fluence Labs, Inc. under the [Apache-2.0](./LICENSE) license.