Why is my Gmail node skipped in my n8n AI agent workflow?

It sounds like the behavior you’re seeing is not an error per se but rather the result of how the workflow’s logic is set up. In n8n, the Gmail node (or any tool node) will only be called when the conditions defined in your workflow are met. For example, if the Gmail node is meant to send or reply to an email only when an email address is found, a conditional node (like an “If” node checking for a valid email via regex) might cause the Gmail node to be bypassed if no email is detected.

Here are a few things to verify:

1. Workflow Conditions:
   Check the node (for example, your “Check if user has provided email” node) that determines whether the Gmail node gets triggered. Make sure that the condition (e.g. a regex to detect valid email addresses) matches the actual input. If the AI agent’s response doesn’t contain an email address or the expected format, then the Gmail node won’t be called.

2. Credentials and Scopes:
   Although the issue here isn’t an authentication error, remember that if you later see errors like “Forbidden – perhaps check your credentials” or a 401 error, it might indicate problems with the Gmail credentials or required scopes (especially if using a Service Account without domain-wide delegation enabled).

   For reference, you might want to review the Gmail node common issues documentation which discusses how to configure credentials and troubleshoot authentication problems.

3. Node Output Indication:
   In n8n, when a tool node is successfully triggered by an AI agent, you’ll see a green border around it. If you don’t see the green border for the Gmail node, that means the node was not activated during that run – likely because the conditions to call it weren’t met.

4. Testing with Different Prompts:
   Since you mentioned trying different prompts with no effect, consider verifying that your prompt includes a valid email address or data that meets your workflow logic. Also, add a debugging node (like a “Set” or “Code” node) before the conditional check to print the AI agent’s output. This will help you confirm whether the expected email data is present.

By ensuring the input meets the conditions required to trigger the Gmail node, you can avoid the issue where the node appears bypassed and make sure your emails are processed as intended.