# Fluence JS Client
[](https://www.npmjs.com/package/@fluencelabs/js-client)
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
> JS Client only supports the ESM format that means not every Node.js project can install it.
> You can read more [here](https://nodejs.org/api/esm.html)
1. Install the client:
```bash
npm i @fluencelabs/js-client
```
2. Add the following lines at the beginning of your code:
```javascript
import { Fluence, randomKras } from "@fluencelabs/js-client";
Fluence.connect(randomKras());
```
### HTML page
Add a script tag with the JS Client module 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/)).
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) and host it yourself. You can find the script in
the `/dist/browser` 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.)
## 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/cli).
1. Install the package:
```bash
npm i -D @fluencelabs/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:
```javascript
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 by passing 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:
```javascript
localStorage.debug = "fluence:*";
```
**NOTE**
In Chromium-based web browsers (e.g. Brave, Chrome, and Electron), the JavaScript console will be default—only to show
messages logged by debug if the "Verbose" log level is enabled.
## Low level usage
JS client also has an API for low level interaction with AVM and Marine JS.
It could be handy in advanced scenarios when a user fetches AIR dynamically or generates AIR without default Aqua compiler.
`callAquaFunction` Allows to call aqua function without schema.
`registerService` Gives an ability to register service without schema. Passed `service` could be
- Plain object. In this case all function properties will be registered as AIR service functions.
- Class instance. All class methods without inherited ones will be registered as AIR service functions.
## 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.