Compose reply draft in Gmail with OpenAI assistant

This workflow uses OpenAI Assistant to compose draft replies for labeled email messages. It automatically connects the drafts to Gmail threads.

💡 You can add knowledge base to your OpenAI Assistant and make your reply drafts very customized (e.g. compose response with product information in response to inquiry from customer).

🎬 See this workflow in action [in my YouTube video](https://youtu.be/a8Dhj3Zh9vQ) about automating Gmail.

How it works?

The workflow is triggered at regular intervals (default: every 1 minute – you can change this value) to check for messages with a specific label (e.g., "AI").

The content of the retrieved email message is then forwarded to the OpenAI Assistant node, and a reply draft is generated. Next, the response from the Assistant is converted to HTML, and a raw message in RFC standard is composed.

💡 You can learn more about composing drafts with the Gmail API in [the official Google documentation](https://developers.google.com/gmail/api/reference/rest/v1/users.drafts/create).

The raw email message (reply draft) is encoded and attached to the original thread ID. Finally, the trigger label (in this case: "AI") is removed to prevent the workflow from looping.