Getting Started

The SignalWire Client-side SDKs transform your browser into a real-time media engine, enabling developers to directly make audio and video calls to phone numbers, SIP endpoints, and other browsers. With few lines of code you can even set up a full-fledged video conferencing system. Using the client-side SDKs you can add immersive, scalable communication — from video conferences and softphones to click-to-call and mobile gaming — all available right in your own web pages and applications.

Depending on your use case, you can choose among two different SDK versions:

• JavaScript SDK v3
• JavaScript SDK v2, previously known as Relay SDK

Both SDKs are JavaScript libraries that run entirely on the browser.

To help get you started, in the following we will introduce two broad and common use cases: for each of them, we suggest which of the two SDKs is the most indicated to the job. Keep into consideration that, in the near future, all functionality of JavaScript SDK v2 will be integrated into JavaScript SDK v3, which will become the reference SDK.

I am building an audio/video conferencing application

If what you are building is closely related to an audio/video conferencing application, which for example should allow the existence of multiple distinct rooms for joining by multiple people, then the JavaScript SDK v3 is likely to be the right tool for the job. This doesn't sound like your use case? Then skip below.

With the JavaScript SDK v3, you will be able to build web pages that can stream your voice and video to other users connected to the same system. You can let your users join or leave virtual rooms with an extremely simple API. In other words, you can use the JavaScript SDK v3 to build your own personalized video conference experience.

Moreover, you have full granular control over the permissions within your system. You can enable some of your users to only join conference calls, while others could list ongoing calls and jump in to assist from a support dashboard. Permissions are handled jointly with the authentication system, which uses JWTs, allowing an easy and secure control of your users' capabilities.

At the moment, the JavaScript SDK v3 does not allow dialing PSTN numbers or SIP endpoints. This will become supported in the near future. For now, it means that all participants should access from a web browser. If you need to dial different endpoints, then perhaps the JavaScript SDK v2 suits you better. Note, however, that with the JavaScript SDK v2 you will have no room support.

Installing the JavaScript SDK v3

Starting to use the JavaScript SDK v3 is as easy as loading a script from a CDN. In fact, that's exactly how you do it:

<script src="https://unpkg.com/@signalwire/js"></script>

Then, you can use the global SignalWire variable in your application. If you prefer, the JavaScript SDK v3 is also available as a NPM package:

$ npm i @signalwire/js

For getting started with the JavaScript SDK v3, take a look at our documentation and API reference.

I am building a one-to-one communication app which should dial other browsers or phones

If what you are building is an application that should allow your users, from their browser, to initiate an audio or video call towards other browsers, phone numbers, or SIP endpoints, then the JavaScript SDK v2 (Relay SDK) is the right choice for you.

By exploiting SignalWire's powerful and flexible Relay API, the JavaScript SDK v2 gives you access to reliable low-latency communication over a broad set of endpoints in a seamless way, both for your users and for the developers.

As an example, with the JavaScript SDK v2 it is extremely easy to build a web-based call center application from which the operator can both dial PSTN phone numbers, and perform internal video-calls. All with the same API.

At the moment, the JavaScript SDK v2 does not support the creation and management of virtual rooms. If you need a multi-room experience, the JavaScript SDK v3 might be more indicated for you. Note, however, that as of today the JavaScript SDK v3 only supports web browser endpoints, so you won't be able to dial PSTN numbers or SIP endpoints while using the JavaScript SDK v3. However, these will be supported soon.

Installing the JavaScript SDK v2

As it is the case for the JavaScript SDK v3, also the JavaScript SDK v2 can be loaded as a script from a CDN. In fact, it can be imported like this:

<script src="https://unpkg.com/@signalwire/[email protected]^1"></script>

Then, you can use the global Relay variable in your application. If you prefer, the JavaScript SDK v2 is also available as a NPM package:

$ npm i @signalwire/[email protected]^1

For getting started with the JavaScript SDK v2, take a look at our documentation and API reference.

Still unsure?

Here are several use-cases, classified according to the SDK that is most indicated for them.