feat: add configurable furniture_mode options to markdown serializer

docling_core/transforms/serializer/markdown.py

@@ -8,7 +8,7 @@
 from pathlib import Path
 from typing import Annotated, Any, Optional, Union
 
-from pydantic import AnyUrl, BaseModel, Field, PositiveInt
+from pydantic import AnyUrl, BaseModel, Field, PositiveInt, model_validator
 from tabulate import _column_type, tabulate
 from typing_extensions import override
 
@@ -144,6 +144,14 @@ class OrigListItemMarkerMode(str, Enum):
     AUTO = "auto"
 
 
+class FurnitureMode(str, Enum):
+    """Display mode for document furniture (headers/footers)."""
+
+    NONE = "none"
+    ALL = "all"
+    DISTINCT = "distinct"
+
+
 class MarkdownParams(CommonParams):
     """Markdown-specific serialization parameters."""
 
@@ -183,6 +191,17 @@ class MarkdownParams(CommonParams):
             )
         ),
     ] = False
+    furniture_mode: FurnitureMode = Field(
+        default=FurnitureMode.NONE,
+        description="Control whether headers and footers are serialized (none, all, or distinct).",
+    )
+
+    @model_validator(mode="after")
+    def _adjust_layers_for_furniture(self) -> "MarkdownParams":
+        """Automatically include FURNITURE layer if mode is not NONE."""
+        if self.furniture_mode != FurnitureMode.NONE:
+            self.layers.add(ContentLayer.FURNITURE)
+        return self
 
 
 class MarkdownTextSerializer(BaseModel, BaseTextSerializer):
@@ -958,6 +977,30 @@ def serialize(
         **kwargs: Any,
     ) -> SerializationResult:
         """Serialize a given node."""
+
+        if item is not None and getattr(item, "content_layer", None) == ContentLayer.FURNITURE:
+            # 'none' mode: skip completely
+            if self.params.furniture_mode == FurnitureMode.NONE:
+                return create_ser_result()
+
+            # 'distinct' mode: deduplicate based on text
+            if self.params.furniture_mode == FurnitureMode.DISTINCT:
+                # Initialize the tracking set on the serializer instance if it doesn't exist
+                if not hasattr(self, "_seen_furniture"):
+                    self._seen_furniture: set[str] = set()
+
+                # Extract text for comparison (fallback to ref if no text exists)
+                item_text = getattr(item, "text", None)
+                if not item_text:
+                    item_text = item.self_ref
+
+                # If we've seen this exact header/footer text before, skip it
+                if item_text in self._seen_furniture:
+                    return create_ser_result()
+
+                # Otherwise, mark it as seen and proceed
+                self._seen_furniture.add(item_text)
+
         return super().serialize(
             item=item,
             list_level=list_level,

test/test_serialization.py

@@ -16,6 +16,7 @@
     HTMLTableSerializer,
 )
 from docling_core.transforms.serializer.markdown import (
+    FurnitureMode,
     MarkdownDocSerializer,
     MarkdownParams,
     MarkdownTableSerializer,
@@ -29,6 +30,7 @@
 from docling_core.types.doc.document import (
     BaseMeta,
     CharSpan,
+    ContentLayer,
     DescriptionAnnotation,
     EntitiesMetaField,
     EntityMention,
@@ -612,6 +614,44 @@ def test_md_traverse_pictures():
     assert "<!-- image -->" in result_with_traverse
 
 
+def test_md_furniture_modes():
+    """Test that furniture_mode correctly filters and deduplicates headers/footers."""
+    doc = DoclingDocument(name="Furniture Test")
+
+    # 1. Add standard body text
+    doc.add_text(label=DocItemLabel.PARAGRAPH, text="Main body paragraph text.")
+
+    # 2. Add headers/footers and tag them as FURNITURE layer items
+    h1 = doc.add_text(label=DocItemLabel.TEXT, text="Document Header Title")
+    h1.content_layer = ContentLayer.FURNITURE
+
+    h2 = doc.add_text(label=DocItemLabel.TEXT, text="Document Header Title")  # Duplicate text
+    h2.content_layer = ContentLayer.FURNITURE
+
+    h3 = doc.add_text(label=DocItemLabel.TEXT, text="Different Footer Notice")
+    h3.content_layer = ContentLayer.FURNITURE
+
+    # Test Mode 1: NONE (Default) -> Should completely drop furniture items
+    ser_none = MarkdownDocSerializer(doc=doc, params=MarkdownParams(furniture_mode=FurnitureMode.NONE))
+    text_none = ser_none.serialize().text
+    assert "Main body paragraph text." in text_none
+    assert "Document Header Title" not in text_none
+
+    # Test Mode 2: ALL -> Should render every furniture item, including duplicates
+    ser_all = MarkdownDocSerializer(doc=doc, params=MarkdownParams(furniture_mode=FurnitureMode.ALL))
+    text_all = ser_all.serialize().text
+    assert "Main body paragraph text." in text_all
+    assert text_all.count("Document Header Title") == 2
+    assert "Different Footer Notice" in text_all
+
+    # Test Mode 3: DISTINCT -> Should render unique text items exactly once
+    ser_distinct = MarkdownDocSerializer(doc=doc, params=MarkdownParams(furniture_mode=FurnitureMode.DISTINCT))
+    text_distinct = ser_distinct.serialize().text
+    assert "Main body paragraph text." in text_distinct
+    assert text_distinct.count("Document Header Title") == 1
+    assert "Different Footer Notice" in text_distinct
+
+
 # ===============================
 # HTML tests
 # ===============================