Specify lenght of arrays in structured outputs

I am giving gpt4o a paged document, that is in a markdown format with page separators like those:

{PAGE 1}------------------------------------------------

![](_page_0_Picture_2.png)

**PLIEGO DE CLÁUSULAS ADMINISTRATIVAS PARTICULARES QUE HA DE REGIR EN EL CONTRATO DE SUMINISTRO E INSTALACIÓN DE DIVERSO EQUIPAMIENTO ELECTROMÉDICO (I) A ADJUDICAR POR PROCEDIMIENTO ABIERTO CON PLURALIDAD DE CRITERIOS** 
...
{PAGE 2}------------------------------------------------
whatever...

Now, I am asking gpt the task to create a global summary and a summary of each page. I am providing this schema:

class PageSummary(BaseModel):
    page_number: int
    summary: str
    questions: list[str]

class PagedSummary(BaseModel):
    global_summary: GlobalSummary
    page_summaries: list[PageSummary]

I would like to force the output to contain, in the list of PageSummarys, exactly the number of pages that each document has. But I don't know whether that is possible or not, maybe I should create a different schema for each document, dynamically? Or is there another way?

Start with the PageSummary and PagedSummary schemas shown in the issue and review the structured-output API behavior they target. Determine whether an exact page_summaries length can be enforced per document or whether dynamically generated schemas are needed; done means identifying and documenting the supported approach.