Nextjs Version:

we provide ready to use sendgrid and mailchimp integration which is define under src/pages/api folder. use this you need to set required credentials at .env.local file.

MAILCHIMP_API_KEY=[your-mailchimp-api-key]
MAILCHIMP_LIST_ID=[your-mailchimp-list-id-key]
SENDGRID_API_KEY=[your-sendgrid-api-key]

to use it on client site we provide a example file at src/components/subscribe. please customize it according to your requirement.

Gatsby Version

we suggest to use gatsby-plugin-mailchimp for mailchimp integration. please follow their docs for more info.