HeyGen Interactive Avatar NextJS Demo

This is a sample project and was bootstrapped using NextJS. Feel free to play around with the existing code and please leave any feedback for the SDK here.

Getting Started FAQ

Setting up the demo

1. Clone this repo

2. Navigate to the repo folder in your terminal

3. Run npm install (assuming you have npm installed. If not, please follow these instructions: https://docs.npmjs.com/downloading-and-installing-node-js-and-npm/)

4. Enter your HeyGen Enterprise API Token or Trial Token in the .env file. Replace PLACEHOLDER-API-KEY with your API key. This will allow the Client app to generate secure Access Tokens with which to create interactive sessions.

   You can retrieve either the API Key or Trial Token by logging in to HeyGen and navigating to this page in your settings: [https://app.heygen.com/settings?nav=API]. NOTE: use the trial token if you don't have an enterprise API token yet.

5. (Optional) If you would like to use the OpenAI features, enter your OpenAI Api Key in the .env file.

6. Run npm run dev

Difference between Trial Token and Enterprise API Token

The HeyGen Trial Token is available to all users, not just Enterprise users, and allows for testing of the Interactive Avatar API, as well as other HeyGen API endpoints.

Each Trial Token is limited to 3 concurrent interactive sessions. However, every interactive session you create with the Trial Token is free of charge, no matter how many tasks are sent to the avatar. Please note that interactive sessions will automatically close after 10 minutes of no tasks sent.

If you do not 'close' the interactive sessions and try to open more than 3, you will encounter errors including stuttering and freezing of the Interactive Avatar. Please endeavor to only have 3 sessions open at any time while you are testing the Interactive Avatar API with your Trial Token.

Starting sessions

NOTE: Make sure you have enter your token into the .env file and run npm run dev.

To start your 'session' with a Interactive Avatar, first click the 'start' button. If your HeyGen API key is entered into the Server's .env file, then you should see our demo Interactive Avatar (Monica!) appear.

After you see Monica appear on the screen, you can enter text into the input labeled 'Repeat', and then hit Enter. The Interactive Avatar will say the text you enter.

If you want to see a different Avatar or try a different voice, you can close the session and enter the IDs and then 'start' the session again. Please see below for information on where to retrieve different Avatar and voice IDs that you can use.

Connecting to OpenAI

A common use case for a Interactive Avatar is to use it as the 'face' of an LLM that users can interact with. In this demo we have included functionality to showcase this by both accepting user input via voice (using OpenAI's Whisper library) and also sending that input to an OpenAI LLM model (using their Chat Completions endpoint).

Both of these features of this demo require an OpenAI API Key. If you do not have a paid OpenAI account, you can learn more on their website: [https://openai.com/index/openai-api/]

Without an OpenAI API Key, this functionality will not work, and the Interactive Avatar will only be able to repeat text input that you provide, and not demonstrate being the 'face' of an LLM. Regardless, this demo is meant to demonstrate what kinds of apps and experiences you can build with our Interactive Avatar SDK, so you can code your own connection to a different LLM if you so choose.

To add your Open AI API Key, fill copy it to the OPENAI_API_KEY and NEXT_PUBLIC_OPENAI_API_KEY variables in the .env file.

How does the integration with OpenAI / ChatGPT work?

In this demo, we are calling the Chat Completions API from OpenAI in order to come up with some response to user input. You can see the relevant code in components/InteractiveAvatar.tsx.

In the initialMessages parameter, you can replace the content of the 'system' message with whatever 'knowledge base' or context that you would like the GPT-4o model to reply to the user's input with.

You can explore this API and the different parameters and models available here: [https://platform.openai.com/docs/guides/text-generation/chat-completions-api]

Which Avatars can I use with this project?

By default, there are several Public Avatars that can be used in Interactive Avatar. (AKA Interactive Avatars.) You can find the Avatar IDs for these Public Avatars by navigating to app.heygen.com/interactive-avatar and clicking 'Select Avatar' and copying the avatar id.

In order to use a private Avatar created under your own account in Interactive Avatar, it must be upgraded to be a Interactive Avatar. Only 1. Finetune Instant Avatars and 2. Studio Avatars are able to be upgraded to Interactive Avatars. This upgrade is a one-time fee and can be purchased by navigating to [app.heygen.com/interactive-avatar] and clicking 'Select Avatar'.

Please note that Photo Avatars are not compatible with Interactive Avatar and cannot be used.

Which voices can I use with my Interactive Avatar?

Most of HeyGen's AI Voices can be used with the Interactive Avatar API. To find the Voice IDs that you can use, please use the List Voices v2 endpoint from HeyGen: [https://docs.heygen.com/reference/list-voices-v2]

Please note that for voices that support Emotions, such as Christine and Tarquin, you need to pass in the Emotion string in the Voice Setting parameter: [https://docs.heygen.com/reference/new-session-copy#voicesetting]

You can also set the speed at which the Interactive Avatar speaks by passing in a Rate in the Voice Setting.

Where can I read more about enterprise-level usage of the Interactive Avatar API?

Please read our Interactive Avatar 101 article for more information on pricing and how to increase your concurrent session limit: https://help.heygen.com/en/articles/9182113-interactive-avatar-101-your-ultimate-guide