Understanding the use of identifier in BinaryContent

[TuanDTr]

Question

Context: I want to compare direct reference of the identifier in the prompt, e.g., "This is image idx" vs. adding the identifier in BinaryContent. My use case is basically inputting a list of images and the model returns the results in a structured output, referencing the image identifier in its answers.

From the documentation, it appears that the parameter seems to be exposed only during tool call. In my case, I don't use any specific tools apart from the structured output. Should the parameter identifier not be helpful in this case?

Additional Context

pydantic-ai version 0.2.20
python version 3.12.11

[DouweM]

@TuanDTr When you're providing BinaryContent as input, it's up to you to also share the identifier with the model, as explained in the docs:

This identifier is only automatically passed to the model when the `BinaryContent` is returned by a tool.
        If you're passing the `BinaryContent` as a user message, it's up to you to include a separate text part with the identifier,
        e.g. "This is file <identifier>:" preceding the `BinaryContent`.

Then, the model will be able to reference the image by identifier in structured output, and you can find the appropriate BinaryContent yourself by comparing the returned value against the known ones.

I think that answers your question, but let me know if not and I can reopen the issue.