Gmail AI Agent: How to Fix 'Invalid id value' Error When Marking Emails as Read in n8n?

Below is an answer based on troubleshooting steps from our documentation for the Gmail node:

It looks like the error

  Bad request – please check your parameters (item 0)
  Invalid id value

is triggered because the node isn’t recognizing the email IDs as valid message IDs. This issue commonly happens when:

• A field is mapped with an incorrect value or JSON property (for example, a different “id” is being passed rather than the one the Gmail API expects)

• The supplied Message ID does not exist or is formatted incorrectly

To resolve this, you can try the following:

1. Verify the ID Value:
   Use a Get or similar operation with the ID you’re planning to use to confirm that it is valid. This confirms that the ID exists in Gmail.

2. Check Your Field Mappings:
   In your workflow, ensure that the field containing the Message ID is mapped correctly to the parameter that marks the message as read. Sometimes data from a previous node may have multiple “id” properties or be nested inside another object. If needed, use a Set node (or Edit Fields node) to explicitly assign the Gmail Message ID to the expected field.

3. Confirm the Correct Parameter:
   The Gmail node requires a valid Message ID, Thread ID, or Label ID depending on your operation. Double-check that you’ve not accidentally passed a different identifier that might be coming through from your summarizing step.

By ensuring that the ID values are valid, formatted correctly, and that you’re mapping the correct JSON property to the action node, you should be able to resolve the error.

Hope this helps you get your workflow running smoothly!