Docker

You can run the example code at examples/example.php in a Docker container.

From the root directory:

cp examples/.env_sample .env

Update the .env file with your SendGrid API Key. If you don't have one, you can get one here.

Add the .env file to your .gitignore file if you are publishing your code publically.

source .env
docker build --build-arg sendgrid_apikey=$SENDGRID_API_KEY -t client .
docker run client php examples/example.php

You should see a list of your SendGrid API Keys.