Binary Image Data Not Transferred to Parent Workflow from Sub-Workflow

It looks like you're encountering the behavior where binary data isn’t passed back from your sub workflow through the AI Agent node. In your case, the sub workflow is correctly generating the image via OpenAI DALL·E, but when the parent AI Agent node receives the response, only table/JSON data is visible and the binary output is missing.

This isn’t an error message per se—the binary data is effectively stripped away when the data flows back from the sub workflow. This behavior is by design in some cases, for example when binary data is not explicitly passed through.

Here are a few suggestions to work around the issue:

• Check the Binary Images Setting:
  n8n provides an option to control whether binary images should be passed through to the agent. You may need to ensure that this option is turned on so that binary output is preserved. (You can refer to the documentation on binary image handling for more details.)

• Use Field References:
  Instead of relying solely on auto-passing the binary data from the sub workflow, consider explicitly setting the output field (the “Put Output in Field” option) to store the binary data. Then, the parent workflow can reference that field.

• Consider Sharing a Link:
  If binary data is not transmitted, one alternative is to store the image somewhere (for example, in a file storage or via an external API that returns a URL) within your sub workflow. Then, return the URL in the JSON response that the parent workflow can consume.

Make sure to double-check your sub workflow and parent node configurations, especially around how binary data is handled in n8n cloud, to see if any additional adjustments are needed.

By controlling these settings, you should be able to tailor the flow of binary data according to your needs. If you run into further issues, consulting the n8n documentation on binary images and AI Agent node configuration can provide more in-depth guidance.