Footnotes Missing from Markdown Output Due to Inability to Include FURNITURE Layer

Docling version: 2.41.0

📌 Problem

When using the docling-serve API to export a PDF as Markdown, footnotes are missing from the result. In contrast, when using the Docling Python library directly, footnotes are included if the FURNITURE layer is explicitly added.

This discrepancy stems from the fact that docling-serve does not expose an option to include or customize content layers—specifically the FURNITURE layer, which contains footnotes, headers, and other secondary text elements.

📄 Reproducible Example

Input PDF:
Recapitulatif_contractuel_bbox_smart_tv_octobre.pdf

Output Source	Result	Screenshot
✅ Docling (Python Library)	Footnotes included
❌ docling-serve API (Markdown export)	Footnotes missing

🔍 Root Cause

Using the Docling library, you can fix this by passing:

include_layers = {
    ContentLayer.BODY,
    ContentLayer.FURNITURE  # This layer contains footnotes
}

✅ Proposed Fix

Allow users of docling-serve to specify the content layers to include during Markdown export.

This would bring the API in line with what’s already possible using the core Python library, which works as follows:

from docling.models import ContentLayer

include_layers = {
    ContentLayer.BODY,
    ContentLayer.FURNITURE  # This includes footnotes, headers, and other marginal text
}

Start at the docling-serve API's Markdown export entry point and compare its options with the Python library's ContentLayer include_layers behavior. Add a way for API users to select content layers, then verify that selecting FURNITURE includes footnotes in the provided PDF's Markdown output.