Adam Culp

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Creating a Video Session in AWS Lambda With Python

Last updated on May 05, 2021

In this post, you'll deploy a Vonage Video OpenTok session client as a microservice to AWS Lambda, written in Python. You do so using this Python application available on Github that uses Flask, and Serverless.

This example application provides the first steps required to utilize the Vonage Video API. This microservice enables applications to request a video chat session. By obtaining a session, you also get a session_id to allow a token request. The corresponding /token request method in this app provides that.


Setup Instructions

Clone the nexmo-community/opentok-session-lambda-python repo from GitHub, and navigate into the newly created directory to proceed.


Rename .env.default to .env and add values to OPENTOK_API_KEY and OPENTOK_API_SECRET provided by your Vonage Video APIs account.


To start, create a virtualenv from within the project root to contain the project as you proceed. Then activate it, as follows:

virtualenv venv --python=python3
source venv/bin/activate

Next, initialize npm and follow the prompts to get it set up. In most cases, you should select the defaults, unless you desire to change any of them. Also, use npm to install some needed dependencies for development to enable Serverless and Lambda to work with the Flask app. Use the following commands to do complete this step.

npm init
npm install --save-dev serverless-wsgi serverless-python-requirements

Now you should use pip to install the required Python dependencies from the requirements.txt included in the cloned code.

pip install -r requirements.txt

Running Local

With the virtualenv set up, you can run the app locally and test things out before deploying to AWS Lambda. You can serve it with the following command:

sls wsgi serve

By default, running locally on your system serves the app at http://localhost:5000. Hitting Ctrl+c closes it down after you finish.

Deploy to Lambda

With all the above finished successfully, you can use Serverless to deploy the app to AWS Lambda.

sls deploy

After deployment, you receive the URL needed to access the application via the API Gateway. Make a note of the URL for the next step.

IMPORTANT: The example application, as-is, does not carry out any authentication or verification. Anyone with access to the URL provided after deployment can access it. Doing so could cause unexpected charges to your Vonage account. Therefore, please secure the app if you intend to leave it active.

Available Endpoints

There are 4 URL endpoints available with this client:

  • GET request to /

    • Doesn't perform any actions, but provides a quick way to test
  • POST request to /session

    • /session provides the session ID.
    • By including a form POST like the following, you can change default parameters used to create a session: (defaults shown as if you leave the body empty.)
location=None, media_mode=relayed, archive_mode=manual

Note: See documentation for media_mode and archive_mode options.

NOTE: Location expects an IP address.

  • /token/<session_id>
    • You can then request a new session by passing the <session_id> to the /token endpoint.

Go to the URL provided by the deploy process. Below are some examples of what requests may look like: (Your URL will vary.)


The / endpoint returns the generic message.


The session endpoint will return the session_id needed to request a token.

The token endpoint will return the token needed to interact with OpenTok.

Deactivating Virtualenv

To exit the virtualenv, you can deactivate it when desired.


Next Steps

If you have any questions or run into troubles, you can reach out to @VonageDev on Twitter or inquire in the Vonage Developer Community Slack team. Good luck.