Zig API Reference

Zig API Reference v5.0.0-rc.3¶

Functions¶

extractBytes()¶

Extract content from a byte array.

This is the main entry point for in-memory extraction. It performs the following steps:

Validate MIME type
Handle legacy format conversion if needed
Select appropriate extractor from registry
Extract content
Run post-processing pipeline

Returns:

An ExtractionResult containing the extracted content and metadata.

Errors:

Returns KreuzbergError.Validation if MIME type is invalid. Returns KreuzbergError.UnsupportedFormat if MIME type is not supported.

Signature:

pub fn extract_bytes(content: []const u8, mime_type: [:0]const u8, config: ExtractionConfig) Error!ExtractionResult

Parameters:

Name	Type	Required	Description
`content`	`[]const u8`	Yes	The byte array to extract
`mimeType`	`[:0]const u8`	Yes	MIME type of the content
`config`	`ExtractionConfig`	Yes	Extraction configuration

Returns: ExtractionResult Errors: Throws Error.

extractFile()¶

Extract content from a file.

This is the main entry point for file-based extraction. It performs the following steps:

Check cache for existing result (if caching enabled)
Detect or validate MIME type
Select appropriate extractor from registry
Extract content
Run post-processing pipeline
Store result in cache (if caching enabled)

Returns:

An ExtractionResult containing the extracted content and metadata.

Errors:

Returns KreuzbergError.Io if the file doesn't exist (NotFound) or for other file I/O errors. Returns KreuzbergError.UnsupportedFormat if MIME type is not supported.

Signature:

pub fn extract_file(path: [:0]const u8, mime_type: ?[:0]const u8, config: ExtractionConfig) Error!ExtractionResult

Parameters:

Name	Type	Required	Description
`path`	`[:0]const u8`	Yes	Path to the file to extract
`mimeType`	`[:0]const u8?`	No	Optional MIME type override. If None, will be auto-detected
`config`	`ExtractionConfig`	Yes	Extraction configuration

Returns: ExtractionResult Errors: Throws Error.

extractFileSync()¶

Synchronous wrapper for extract_file.

This is a convenience function that blocks the current thread until extraction completes. For async code, use extract_file directly.

Uses the global Tokio runtime for 100x+ performance improvement over creating a new runtime per call. Always uses the global runtime to avoid nested runtime issues.

This function is only available with the tokio-runtime feature. For WASM targets, use a truly synchronous extraction approach instead.

Signature:

pub fn extract_file_sync(path: [:0]const u8, mime_type: ?[:0]const u8, config: ExtractionConfig) Error!ExtractionResult

Parameters:

Name	Type	Required	Description
`path`	`[:0]const u8`	Yes	Path to the file
`mimeType`	`[:0]const u8?`	No	The mime type
`config`	`ExtractionConfig`	Yes	The configuration options

Returns: ExtractionResult Errors: Throws Error.

extractBytesSync()¶

Synchronous wrapper for extract_bytes.

Uses the global Tokio runtime for 100x+ performance improvement over creating a new runtime per call.

With the tokio-runtime feature, this blocks the current thread using the global Tokio runtime. Without it (WASM), this calls a truly synchronous implementation.

Signature:

pub fn extract_bytes_sync(content: []const u8, mime_type: [:0]const u8, config: ExtractionConfig) Error!ExtractionResult

Parameters:

Name	Type	Required	Description
`content`	`[]const u8`	Yes	The content to process
`mimeType`	`[:0]const u8`	Yes	The mime type
`config`	`ExtractionConfig`	Yes	The configuration options

Returns: ExtractionResult Errors: Throws Error.

batchExtractFilesSync()¶

Synchronous wrapper for batch_extract_files.

Uses the global Tokio runtime for optimal performance. Only available with tokio-runtime (WASM has no filesystem).

Signature:

pub fn batch_extract_files_sync(items: []const BatchFileItem, config: ExtractionConfig) Error![]const ExtractionResult

Parameters:

Name	Type	Required	Description
`items`	`[]const BatchFileItem`	Yes	The items
`config`	`ExtractionConfig`	Yes	The configuration options

Returns: []const ExtractionResult Errors: Throws Error.

batchExtractBytesSync()¶

Synchronous wrapper for batch_extract_bytes.

Uses the global Tokio runtime for optimal performance. With the tokio-runtime feature, this blocks the current thread using the global Tokio runtime. Without it (WASM), this calls a truly synchronous implementation that iterates through items and calls extract_bytes_sync().

Signature:

pub fn batch_extract_bytes_sync(items: []const BatchBytesItem, config: ExtractionConfig) Error![]const ExtractionResult

Parameters:

Name	Type	Required	Description
`items`	`[]const BatchBytesItem`	Yes	The items
`config`	`ExtractionConfig`	Yes	The configuration options

Returns: []const ExtractionResult Errors: Throws Error.

batchExtractFiles()¶

Extract content from multiple files concurrently.

This function processes multiple files in parallel, automatically managing concurrency to prevent resource exhaustion. The concurrency limit can be configured via ExtractionConfig.max_concurrent_extractions or defaults to (num_cpus * 1.5).ceil().

Each file can optionally specify a FileExtractionConfig that overrides specific fields from the batch-level config. Pass null for a file to use the batch defaults. Batch-level settings like max_concurrent_extractions and use_cache are always taken from the batch-level config.

per-file configuration overrides.

config - Batch-level extraction configuration (provides defaults and batch settings)

Returns:

A vector of ExtractionResult in the same order as the input items.

Errors:

Individual file errors are captured in the result metadata. System errors (IO, RuntimeError equivalents) will bubble up and fail the entire batch.

Simple usage with no per-file overrides:

Per-file configuration overrides:

Signature:

pub fn batch_extract_files(items: []const BatchFileItem, config: ExtractionConfig) Error![]const ExtractionResult

Parameters:

Name	Type	Required	Description
`items`	`[]const BatchFileItem`	Yes	Vector of `BatchFileItem` structs, each containing a path and optional
`config`	`ExtractionConfig`	Yes	Batch-level extraction configuration (provides defaults and batch settings)

Returns: []const ExtractionResult Errors: Throws Error.

batchExtractBytes()¶

Extract content from multiple byte arrays concurrently.

This function processes multiple byte arrays in parallel, automatically managing concurrency to prevent resource exhaustion. The concurrency limit can be configured via ExtractionConfig.max_concurrent_extractions or defaults to (num_cpus * 1.5).ceil().

Each item can optionally specify a FileExtractionConfig that overrides specific fields from the batch-level config. Pass null as the config to use the batch-level defaults for that item.

MIME type, and optional per-item configuration overrides.

config - Batch-level extraction configuration

Returns:

A vector of ExtractionResult in the same order as the input items.

Simple usage with no per-item overrides:

Per-item configuration overrides:

Signature:

pub fn batch_extract_bytes(items: []const BatchBytesItem, config: ExtractionConfig) Error![]const ExtractionResult

Parameters:

Name	Type	Required	Description
`items`	`[]const BatchBytesItem`	Yes	Vector of `BatchBytesItem` structs, each containing content bytes,
`config`	`ExtractionConfig`	Yes	Batch-level extraction configuration

Returns: []const ExtractionResult Errors: Throws Error.

detectMimeTypeFromBytes()¶

Detect MIME type from raw file bytes.

Uses magic byte signatures to detect file type from content. Falls back to infer crate for comprehensive detection.

For ZIP-based files, inspects contents to distinguish Office Open XML formats (DOCX, XLSX, PPTX) from plain ZIP archives.

Returns:

The detected MIME type string.

Errors:

Returns KreuzbergError.UnsupportedFormat if MIME type cannot be determined.

Signature:

pub fn detect_mime_type_from_bytes(content: []const u8) Error![:0]const u8

Parameters:

Name	Type	Required	Description
`content`	`[]const u8`	Yes	Raw file bytes

Returns: [:0]const u8 Errors: Throws Error.

getExtensionsForMime()¶

Get file extensions for a given MIME type.

Returns all known file extensions that map to the specified MIME type.

Returns:

A vector of file extensions (without leading dot) for the MIME type.

Signature:

pub fn get_extensions_for_mime(mime_type: [:0]const u8) Error![]const [:0]const u8

Parameters:

Name	Type	Required	Description
`mimeType`	`[:0]const u8`	Yes	The MIME type to look up

Returns: []const [:0]const u8 Errors: Throws Error.

clearEmbeddingBackends()¶

Clear all embedding backends from the global registry.

Calls shutdown() on every registered backend, then empties the registry.

Errors:

Any error returned by a backend's shutdown() method. The first error encountered stops processing of remaining backends.

Signature:

pub fn clear_embedding_backends() Error!void

Returns: void Errors: Throws Error.

listEmbeddingBackends()¶

List the names of all registered embedding backends.

Used by kreuzberg-cli and the api/mcp endpoints; excluded from the language bindings via alef.toml [exclude].functions.

Signature:

pub fn list_embedding_backends() Error![]const [:0]const u8

Returns: []const [:0]const u8 Errors: Throws Error.

listDocumentExtractors()¶

List names of all registered document extractors.

Signature:

pub fn list_document_extractors() Error![]const [:0]const u8

Returns: []const [:0]const u8 Errors: Throws Error.

clearDocumentExtractors()¶

Clear all document extractors from the global registry.

Calls shutdown() on every registered extractor, then empties the registry.

Errors:

Any error returned by an extractor's shutdown() method. The first error encountered stops processing of remaining extractors.

Signature:

pub fn clear_document_extractors() Error!void

Returns: void Errors: Throws Error.

listOcrBackends()¶

List all registered OCR backends.

Returns the names of all OCR backends currently registered in the global registry.

Returns:

A vector of OCR backend names.

Signature:

pub fn list_ocr_backends() Error![]const [:0]const u8

Returns: []const [:0]const u8 Errors: Throws Error.

clearOcrBackends()¶

Clear all OCR backends from the global registry.

Removes all OCR backends and calls their shutdown() methods.

Returns:

Ok(()) if all backends were cleared successfully
Err(...) if any shutdown method failed

Signature:

pub fn clear_ocr_backends() Error!void

Returns: void Errors: Throws Error.

listPostProcessors()¶

List all registered post-processor names.

Returns a vector of all post-processor names currently registered in the global registry.

Returns:

Ok(Vec<String>) - Vector of post-processor names
Err(...) if the registry lock is poisoned

Signature:

pub fn list_post_processors() Error![]const [:0]const u8

Returns: []const [:0]const u8 Errors: Throws Error.

clearPostProcessors()¶

Remove all registered post-processors.

Signature:

pub fn clear_post_processors() Error!void

Returns: void Errors: Throws Error.

listRenderers()¶

List names of all registered renderers.

Errors:

Returns an error if the registry lock is poisoned.

Signature:

pub fn list_renderers() Error![]const [:0]const u8

Returns: []const [:0]const u8 Errors: Throws Error.

clearRenderers()¶

Clear all renderers from the global registry.

Removes every renderer, including the built-in defaults (markdown, html, djot, plain). After calling this no renderers are registered; re-register as needed.

Errors:

Returns an error if the registry lock is poisoned.

Signature:

pub fn clear_renderers() Error!void

Returns: void Errors: Throws Error.

listValidators()¶

List names of all registered validators.

Signature:

pub fn list_validators() Error![]const [:0]const u8

Returns: []const [:0]const u8 Errors: Throws Error.

clearValidators()¶

Remove all registered validators.

Signature:

pub fn clear_validators() Error!void

Returns: void Errors: Throws Error.

embedTextsAsync()¶

Generate embeddings asynchronously for a list of text strings.

This is the async counterpart to embed_texts. It offloads the blocking ONNX inference work to a dedicated blocking thread pool via Tokio's spawn_blocking, keeping the async executor free.

Returns one embedding vector per input text in the same order.

Errors:

KreuzbergError.MissingDependency if ONNX Runtime is not installed
KreuzbergError.Embedding if the preset name is unknown, model download fails, or the blocking inference task panics

Signature:

pub fn embed_texts_async(texts: []const [:0]const u8, config: EmbeddingConfig) Error![]const []const f32

Parameters:

Name	Type	Required	Description
`texts`	`[]const [:0]const u8`	Yes	Vec of strings to embed (owned, sent to blocking thread)
`config`	`EmbeddingConfig`	Yes	Embedding configuration specifying model, batch size, and normalization

Returns: []const []const f32 Errors: Throws Error.

renderPdfPageToPng()¶

Render a single PDF page to PNG bytes.

Returns raw PNG-encoded bytes for the specified page at the given DPI. Uses pdf_oxide with tiny-skia for pure-Rust rendering.

Errors:

Returns KreuzbergError.Parsing if the PDF cannot be opened, authenticated, or rendered, or if page_index is out of range.

Signature:

pub fn render_pdf_page_to_png(pdf_bytes: []const u8, page_index: u64, dpi: ?i32, password: ?[:0]const u8) Error![]const u8

Parameters:

Name	Type	Required	Description
`pdfBytes`	`[]const u8`	Yes	Raw PDF file bytes
`pageIndex`	`u64`	Yes	Zero-based page index
`dpi`	`i32?`	No	Resolution in dots per inch (default: 150)
`password`	`[:0]const u8?`	No	Optional password for encrypted PDFs

Returns: []const u8 Errors: Throws Error.

detectMimeType()¶

Detect the MIME type of a file at the given path.

Uses the file extension and optionally the file content to determine the MIME type. Set check_exists to true to verify the file exists before detection.

Signature:

pub fn detect_mime_type(path: [:0]const u8, check_exists: bool) Error![:0]const u8

Parameters:

Name	Type	Required	Description
`path`	`[:0]const u8`	Yes	Path to the file
`checkExists`	`bool`	Yes	The check exists

Returns: [:0]const u8 Errors: Throws Error.

embedTexts()¶

Embed a list of texts using the configured embedding model.

Returns a 2D vector where each inner vector is the embedding for the corresponding text.

Signature:

pub fn embed_texts(texts: []const [:0]const u8, config: EmbeddingConfig) Error![]const []const f32

Parameters:

Name	Type	Required	Description
`texts`	`[]const [:0]const u8`	Yes	The texts
`config`	`EmbeddingConfig`	Yes	The configuration options

Returns: []const []const f32 Errors: Throws Error.

getEmbeddingPreset()¶

Get an embedding preset by name.

Returns null if no preset with the given name exists. Returns an owned clone so the value is safe to pass across FFI boundaries.

Signature:

pub fn get_embedding_preset(name: [:0]const u8) ?EmbeddingPreset

Parameters:

Name	Type	Required	Description
`name`	`[:0]const u8`	Yes	The name

Returns: ?EmbeddingPreset

listEmbeddingPresets()¶

List the names of all available embedding presets.

Returns owned Strings so the values are safe to pass across FFI boundaries.

Signature:

pub fn list_embedding_presets() []const [:0]const u8

Returns: []const [:0]const u8

Types¶

AccelerationConfig¶

Hardware acceleration configuration for ONNX Runtime models.

Controls which execution provider (CPU, CoreML, CUDA, TensorRT) is used for inference in layout detection and embedding generation.

Field	Type	Default	Description
`provider`	`ExecutionProviderType`	`ExecutionProviderType.Auto`	Execution provider to use for ONNX inference.
`deviceId`	`u32`	—	GPU device ID (for CUDA/TensorRT). Ignored for CPU/CoreML/Auto.

ArchiveEntry¶

A single file extracted from an archive.

When archives (ZIP, TAR, 7Z, GZIP) are extracted with recursive extraction enabled, each processable file produces its own full ExtractionResult.

Field	Type	Default	Description
`path`	`[:0]const u8`	—	Archive-relative file path (e.g. "folder/document.pdf").
`mimeType`	`[:0]const u8`	—	Detected MIME type of the file.
`result`	`ExtractionResult`	—	Full extraction result for this file.

ArchiveMetadata¶

Archive (ZIP/TAR/7Z) metadata.

Extracted from compressed archive files containing file lists and size information.

Field	Type	Default	Description
`format`	`[:0]const u8`	—	Archive format ("ZIP", "TAR", "7Z", etc.)
`fileCount`	`u32`	—	Total number of files in the archive
`fileList`	`[]const [:0]const u8`	`[]`	List of file paths within the archive
`totalSize`	`u64`	—	Total uncompressed size in bytes
`compressedSize`	`u64?`	`null`	Compressed size in bytes (if available)

BBox¶

Bounding box in original image coordinates (x1, y1) top-left, (x2, y2) bottom-right.

Field	Type	Default	Description
`x1`	`f32`	—	X1
`y1`	`f32`	—	Y1
`x2`	`f32`	—	X2
`y2`	`f32`	—	Y2

BatchBytesItem¶

Batch item for byte array extraction.

Used with batch_extract_bytes and batch_extract_bytes_sync to represent a single item in a batch extraction job.

Field	Type	Default	Description
`content`	`[]const u8`	—	The content bytes to extract from
`mimeType`	`[:0]const u8`	—	MIME type of the content (e.g., "application/pdf", "text/html")
`config`	`FileExtractionConfig?`	`null`	Per-item configuration overrides (None uses batch-level defaults)

BatchFileItem¶

Batch item for file extraction.

Used with batch_extract_files and batch_extract_files_sync to represent a single file in a batch extraction job.

Field	Type	Default	Description
`path`	`[:0]const u8`	—	Path to the file to extract from
`config`	`FileExtractionConfig?`	`null`	Per-file configuration overrides (None uses batch-level defaults)

BibtexMetadata¶

BibTeX bibliography metadata.

Field	Type	Default	Description
`entryCount`	`u64`	—	Number of entries in the bibliography.
`citationKeys`	`[]const [:0]const u8`	`[]`	Citation keys
`authors`	`[]const [:0]const u8`	`[]`	Authors
`yearRange`	`YearRange?`	`null`	Year range (year range)
`entryTypes`	`std.StringHashMap(u64)?`	`{}`	Entry types

BoundingBox¶

Bounding box coordinates for element positioning.

Field	Type	Default	Description
`x0`	`f64`	—	Left x-coordinate
`y0`	`f64`	—	Bottom y-coordinate
`x1`	`f64`	—	Right x-coordinate
`y1`	`f64`	—	Top y-coordinate

Chunk¶

A text chunk with optional embedding and metadata.

Chunks are created when chunking is enabled in ExtractionConfig. Each chunk contains the text content, optional embedding vector (if embedding generation is configured), and metadata about its position in the document.

Field	Type	Default	Description
`content`	`[:0]const u8`	—	The text content of this chunk.
`chunkType`	`ChunkType`	`/* serde(default) */`	Semantic structural classification of this chunk. Assigned by the heuristic classifier based on content patterns and heading context. Defaults to `ChunkType.Unknown` when no rule matches.
`embedding`	`[]const f32?`	`null`	Optional embedding vector for this chunk. Only populated when `EmbeddingConfig` is provided in chunking configuration. The dimensionality depends on the chosen embedding model.
`metadata`	`ChunkMetadata`	—	Metadata about this chunk's position and properties.

ChunkMetadata¶

Metadata about a chunk's position in the original document.

Field	Type	Default	Description
`byteStart`	`u64`	—	Byte offset where this chunk starts in the original text (UTF-8 valid boundary).
`byteEnd`	`u64`	—	Byte offset where this chunk ends in the original text (UTF-8 valid boundary).
`tokenCount`	`u64?`	`null`	Number of tokens in this chunk (if available). This is calculated by the embedding model's tokenizer if embeddings are enabled.
`chunkIndex`	`u64`	—	Zero-based index of this chunk in the document.
`totalChunks`	`u64`	—	Total number of chunks in the document.
`firstPage`	`u32?`	`null`	First page number this chunk spans (1-indexed). Only populated when page tracking is enabled in extraction configuration.
`lastPage`	`u32?`	`null`	Last page number this chunk spans (1-indexed, equal to first_page for single-page chunks). Only populated when page tracking is enabled in extraction configuration.
`headingContext`	`HeadingContext?`	`/* serde(default) */`	Heading context when using Markdown chunker. Contains the heading hierarchy this chunk falls under. Only populated when `ChunkerType.Markdown` is used.
`imageIndices`	`[]const u32`	`/* serde(default) */`	Indices into `ExtractionResult.images` for images on pages covered by this chunk. Contains zero-based indices into the top-level `images` collection for every image whose `page_number` falls within `[first_page, last_page]`. Empty when image extraction is disabled or the chunk spans no pages with images.

ChunkingConfig¶

Chunking configuration.

Configures text chunking for document content, including chunk size, overlap, trimming behavior, and optional embeddings.

Use ..the default constructor when constructing to allow for future field additions:

Field	Type	Default	Description
`maxCharacters`	`u64`	`1000`	Maximum size per chunk (in units determined by `sizing`). When `sizing` is `Characters` (default), this is the max character count. When using token-based sizing, this is the max token count. Default: 1000
`overlap`	`u64`	`200`	Overlap between chunks (in units determined by `sizing`). Default: 200
`trim`	`bool`	`true`	Whether to trim whitespace from chunk boundaries. Default: true
`chunkerType`	`ChunkerType`	`ChunkerType.Text`	Type of chunker to use (Text or Markdown). Default: Text
`embedding`	`EmbeddingConfig?`	`null`	Optional embedding configuration for chunk embeddings.
`preset`	`[:0]const u8?`	`null`	Use a preset configuration (overrides individual settings if provided).
`sizing`	`ChunkSizing`	`ChunkSizing.Characters`	How to measure chunk size. Default: `Characters` (Unicode character count). Enable `chunking-tiktoken` or `chunking-tokenizers` features for token-based sizing.
`prependHeadingContext`	`bool`	`false`	When `true` and `chunker_type` is `Markdown`, prepend the heading hierarchy path (e.g. `"# Title > ## Section\n\n"`) to each chunk's content string. This is useful for RAG pipelines where each chunk needs self-contained context about its position in the document structure. Default: `false`
`topicThreshold`	`f32?`	`null`	Optional cosine similarity threshold for semantic topic boundary detection. Only used when `chunker_type` is `Semantic` and an `EmbeddingConfig` is provided. You almost never need to set this. When omitted, defaults to `0.75` which works well for most documents. Lower values detect more topic boundaries (more, smaller chunks); higher values detect fewer. Range: `0.0..=1.0`.

Methods¶

default()¶

Signature:

pub fn default() ChunkingConfig

CitationMetadata¶

Citation file metadata (RIS, PubMed, EndNote).

Field	Type	Default	Description
`citationCount`	`u64`	—	Number of citations
`format`	`[:0]const u8?`	`null`	Format
`authors`	`[]const [:0]const u8`	`[]`	Authors
`yearRange`	`YearRange?`	`null`	Year range (year range)
`dois`	`[]const [:0]const u8`	`[]`	Dois
`keywords`	`[]const [:0]const u8`	`[]`	Keywords

ContentFilterConfig¶

Cross-extractor content filtering configuration.

Controls whether "furniture" content (headers, footers, page numbers, watermarks, repeating text) is included in or stripped from extraction results. Applies across all extractors (PDF, DOCX, RTF, ODT, HTML, etc.) with format-specific implementation.

When null on ExtractionConfig, each extractor uses its current default behavior unchanged.

Field	Type	Default	Description
`includeHeaders`	`bool`	`false`	Include running headers in extraction output. - PDF: Disables top-margin furniture stripping and prevents the layout model from treating `PageHeader`-classified regions as furniture. - DOCX: Includes document headers in text output. - RTF/ODT: Headers already included; this is a no-op when true. - HTML/EPUB: Keeps `<header>` element content. Default: `false` (headers are stripped or excluded).
`includeFooters`	`bool`	`false`	Include running footers in extraction output. - PDF: Disables bottom-margin furniture stripping and prevents the layout model from treating `PageFooter`-classified regions as furniture. - DOCX: Includes document footers in text output. - RTF/ODT: Footers already included; this is a no-op when true. - HTML/EPUB: Keeps `<footer>` element content. Default: `false` (footers are stripped or excluded).
`stripRepeatingText`	`bool`	`true`	Enable the heuristic cross-page repeating text detector. When `true` (default), text that repeats verbatim across a supermajority of pages is classified as furniture and stripped. Disable this if brand names or repeated headings are being incorrectly removed by the heuristic. Note: when a layout-detection model is active, the model may independently classify page-header / page-footer regions as furniture on a per-page basis. To preserve those regions, set `include_headers = true`, `include_footers = true`, or both, in addition to disabling this flag. Primarily affects PDF extraction. Default: `true`.
`includeWatermarks`	`bool`	`false`	Include watermark text in extraction output. - PDF: Keeps watermark artifacts and arXiv identifiers. - Other formats: No effect currently. Default: `false` (watermarks are stripped).

Methods¶

default()¶

Signature:

pub fn default() ContentFilterConfig

ContributorRole¶

JATS contributor with role.

Field	Type	Default	Description
`name`	`[:0]const u8`	—	The name
`role`	`[:0]const u8?`	`null`	Role

CoreProperties¶

Dublin Core metadata from docProps/core.xml

Contains standard metadata fields defined by the Dublin Core standard and Office-specific extensions.

Field	Type	Default	Description
`title`	`[:0]const u8?`	`null`	Document title
`subject`	`[:0]const u8?`	`null`	Document subject/topic
`creator`	`[:0]const u8?`	`null`	Document creator/author
`keywords`	`[:0]const u8?`	`null`	Keywords or tags
`description`	`[:0]const u8?`	`null`	Document description/abstract
`lastModifiedBy`	`[:0]const u8?`	`null`	User who last modified the document
`revision`	`[:0]const u8?`	`null`	Revision number
`created`	`[:0]const u8?`	`null`	Creation timestamp (ISO 8601)
`modified`	`[:0]const u8?`	`null`	Last modification timestamp (ISO 8601)
`category`	`[:0]const u8?`	`null`	Document category
`contentStatus`	`[:0]const u8?`	`null`	Content status (Draft, Final, etc.)
`language`	`[:0]const u8?`	`null`	Document language
`identifier`	`[:0]const u8?`	`null`	Unique identifier
`version`	`[:0]const u8?`	`null`	Document version
`lastPrinted`	`[:0]const u8?`	`null`	Last print timestamp (ISO 8601)

CsvMetadata¶

CSV/TSV file metadata.

Field	Type	Default	Description
`rowCount`	`u32`	—	Number of rows
`columnCount`	`u32`	—	Number of columns
`delimiter`	`[:0]const u8?`	`null`	Delimiter
`hasHeader`	`bool`	—	Whether header
`columnTypes`	`[]const [:0]const u8?`	`[]`	Column types

DbfFieldInfo¶

dBASE field information.

Field	Type	Default	Description
`name`	`[:0]const u8`	—	The name
`fieldType`	`[:0]const u8`	—	Field type

DbfMetadata¶

dBASE (DBF) file metadata.

Field	Type	Default	Description
`recordCount`	`u64`	—	Number of records
`fieldCount`	`u64`	—	Number of fields
`fields`	`[]const DbfFieldInfo`	`[]`	Fields

DetectResponse¶

MIME type detection response.

Field	Type	Default	Description
`mimeType`	`[:0]const u8`	—	Detected MIME type
`filename`	`[:0]const u8?`	`null`	Original filename (if provided)

DetectionResult¶

Page-level detection result containing all detections and page metadata.

Field	Type	Default	Description
`pageWidth`	`u32`	—	Page width
`pageHeight`	`u32`	—	Page height
`detections`	`[]const LayoutDetection`	—	Detections

DjotContent¶

Comprehensive Djot document structure with semantic preservation.

This type captures the full richness of Djot markup, including:

Block-level structures (headings, lists, blockquotes, code blocks, etc.)
Inline formatting (emphasis, strong, highlight, subscript, superscript, etc.)
Attributes (classes, IDs, key-value pairs)
Links, images, footnotes
Math expressions (inline and display)
Tables with full structure

Available when the djot feature is enabled.

Field	Type	Default	Description
`plainText`	`[:0]const u8`	—	Plain text representation for backwards compatibility
`blocks`	`[]const FormattedBlock`	—	Structured block-level content
`metadata`	`Metadata`	—	Metadata from YAML frontmatter
`tables`	`[]const Table`	—	Extracted tables as structured data
`images`	`[]const DjotImage`	—	Extracted images with metadata
`links`	`[]const DjotLink`	—	Extracted links with URLs
`footnotes`	`[]const Footnote`	—	Footnote definitions
`attributes`	`[]const [:0]const u8`	`/* serde(default) */`	Attributes mapped by element identifier (if present)

DjotImage¶

Image element in Djot.

Field	Type	Default	Description
`src`	`[:0]const u8`	—	Image source URL or path
`alt`	`[:0]const u8`	—	Alternative text
`title`	`[:0]const u8?`	`null`	Optional title
`attributes`	`[:0]const u8?`	`null`	Element attributes

DjotLink¶

Link element in Djot.

Field	Type	Default	Description
`url`	`[:0]const u8`	—	Link URL
`text`	`[:0]const u8`	—	Link text content
`title`	`[:0]const u8?`	`null`	Optional title
`attributes`	`[:0]const u8?`	`null`	Element attributes

DocumentExtractor¶

Trait for document extractor plugins.

Implement this trait to add support for new document formats or to override built-in extraction behavior with custom logic.

Return Type¶

Extractors return InternalDocument, a flat intermediate representation. The pipeline converts this into the public ExtractionResult via the derivation step.

Priority System¶

When multiple extractors support the same MIME type, the registry selects the extractor with the highest priority value. Use this to:

Override built-in extractors (priority > 50)
Provide fallback extractors (priority < 50)
Implement specialized extractors for specific use cases

Default priority is 50.

Thread Safety¶

Extractors must be thread-safe (Send + Sync) to support concurrent extraction.

Methods¶

extractBytes()¶

Extract content from a byte array.

This is the core extraction method that processes in-memory document data.

Returns:

An InternalDocument containing the extracted elements, metadata, and tables. The pipeline will convert this into the public ExtractionResult.

Errors:

KreuzbergError.Parsing - Document parsing failed
KreuzbergError.Validation - Invalid document structure
KreuzbergError.Io - I/O errors (these always bubble up)
KreuzbergError.MissingDependency - Required dependency not available

Signature:

pub fn extractBytes(self: *const DocumentExtractor, content: []const u8, mime_type: [:0]const u8, config: ExtractionConfig) Error!InternalDocument

extractFile()¶

Extract content from a file.

Default implementation reads the file and calls extract_bytes. Override for custom file handling, streaming, or memory optimizations.

Returns:

An InternalDocument containing the extracted elements, metadata, and tables.

Errors:

Same as extract_bytes, plus file I/O errors.

Signature:

pub fn extractFile(self: *const DocumentExtractor, path: [:0]const u8, mime_type: [:0]const u8, config: ExtractionConfig) Error!InternalDocument

supportedMimeTypes()¶

Get the list of MIME types supported by this extractor.

Can include exact MIME types and prefix patterns:

Exact: "application/pdf", "text/plain"
Prefix: "image/*" (matches any image type)

Returns:

A slice of MIME type strings.

Signature:

pub fn supportedMimeTypes(self: *const DocumentExtractor) []const [:0]const u8

priority()¶

Get the priority of this extractor.

Higher priority extractors are preferred when multiple extractors support the same MIME type.

Priority Guidelines¶

0-25: Fallback/low-quality extractors
26-49: Alternative extractors
50: Default priority (built-in extractors)
51-75: Premium/enhanced extractors
76-100: Specialized/high-priority extractors

Returns:

Priority value (default: 50)

Signature:

pub fn priority(self: *const DocumentExtractor) i32

canHandle()¶

Optional: Check if this extractor can handle a specific file.

Allows for more sophisticated detection beyond MIME types. Defaults to true (rely on MIME type matching).

Returns:

true if the extractor can handle this file, false otherwise.

Signature:

pub fn canHandle(self: *const DocumentExtractor, path: [:0]const u8, mime_type: [:0]const u8) bool

asSyncExtractor()¶

Attempt to get a reference to this extractor as a SyncExtractor.

Returns None if the extractor doesn't support synchronous extraction. This is used for WASM and other sync-only environments.

Signature:

pub fn asSyncExtractor(self: *const DocumentExtractor) ?SyncExtractor

DocumentNode¶

A single node in the document tree.

Each node has deterministic id, typed content, optional parent/children for tree structure, and metadata like page number, bounding box, and content layer.

Field	Type	Default	Description
`id`	`[:0]const u8`	—	Deterministic identifier (hash of content + position).
`content`	`NodeContent`	—	Node content — tagged enum, type-specific data only.
`parent`	`u32?`	`null`	Parent node index (`null` = root-level node).
`children`	`[]const u32`	`/* serde(default) */`	Child node indices in reading order.
`contentLayer`	`ContentLayer`	`/* serde(default) */`	Content layer classification.
`page`	`u32?`	`null`	Page number where this node starts (1-indexed).
`pageEnd`	`u32?`	`null`	Page number where this node ends (for multi-page tables/sections).
`bbox`	`BoundingBox?`	`null`	Bounding box in document coordinates.
`annotations`	`[]const TextAnnotation`	`/* serde(default) */`	Inline annotations (formatting, links) on this node's text content. Only meaningful for text-carrying nodes; empty for containers.
`attributes`	`std.StringHashMap([:0]const u8)?`	`null`	Format-specific key-value attributes. Extensible bag for miscellaneous data without a dedicated typed field: CSS classes, LaTeX environment names, Excel cell formulas, slide layout names, etc.

DocumentRelationship¶

A resolved relationship between two nodes in the document tree.

Field	Type	Default	Description
`source`	`u32`	—	Source node index (the referencing node).
`target`	`u32`	—	Target node index (the referenced node).
`kind`	`RelationshipKind`	—	Semantic kind of the relationship.

DocumentStructure¶

Top-level structured document representation.

A flat array of nodes with index-based parent/child references forming a tree. Root-level nodes have parent: None. Use body_roots() and furniture_roots() to iterate over top-level content by layer.

Validation¶

Call validate() after construction to verify all node indices are in bounds and parent-child relationships are bidirectionally consistent.

Field	Type	Default	Description
`nodes`	`[]const DocumentNode`	`[]`	All nodes in document/reading order.
`sourceFormat`	`[:0]const u8?`	`null`	Origin format identifier (e.g. "docx", "pptx", "html", "pdf"). Allows renderers to apply format-aware heuristics when converting the document tree to output formats.
`relationships`	`[]const DocumentRelationship`	`[]`	Resolved relationships between nodes (footnote refs, citations, anchor links, etc.). Populated during derivation from the internal document representation. Empty when no relationships are detected.
`nodeTypes`	`[]const [:0]const u8`	`[]`	Sorted, deduplicated list of node type names present in this document. Each value is the snake_case `node_type` tag of the corresponding `NodeContent` variant (e.g. `"paragraph"`, `"heading"`, `"table"`, …). Computed from `nodes` via `DocumentStructure.finalize_node_types`. Empty until that method is called (internal construction paths call it at the end of derivation).

Methods¶

finalizeNodeTypes()¶

Compute and populate the node_types field from the current nodes.

Call this after all nodes have been added to the structure. Internal construction paths (builder, derivation) call this automatically.

Signature:

pub fn finalizeNodeTypes(self: *const DocumentStructure) void

isEmpty()¶

Check if the document structure is empty.

Signature:

pub fn isEmpty(self: *const DocumentStructure) bool

default()¶

Signature:

pub fn default() DocumentStructure

DocxAppProperties¶

Application properties from docProps/app.xml for DOCX

Contains Word-specific document statistics and metadata.

Field	Type	Default	Description
`application`	`[:0]const u8?`	`null`	Application name (e.g., "Microsoft Office Word")
`appVersion`	`[:0]const u8?`	`null`	Application version
`template`	`[:0]const u8?`	`null`	Template filename
`totalTime`	`i32?`	`null`	Total editing time in minutes
`pages`	`i32?`	`null`	Number of pages
`words`	`i32?`	`null`	Number of words
`characters`	`i32?`	`null`	Number of characters (excluding spaces)
`charactersWithSpaces`	`i32?`	`null`	Number of characters (including spaces)
`lines`	`i32?`	`null`	Number of lines
`paragraphs`	`i32?`	`null`	Number of paragraphs
`company`	`[:0]const u8?`	`null`	Company name
`docSecurity`	`i32?`	`null`	Document security level
`scaleCrop`	`bool?`	`null`	Scale crop flag
`linksUpToDate`	`bool?`	`null`	Links up to date flag
`sharedDoc`	`bool?`	`null`	Shared document flag
`hyperlinksChanged`	`bool?`	`null`	Hyperlinks changed flag

DocxMetadata¶

Word document metadata.

Extracted from DOCX files using shared Office Open XML metadata extraction. Integrates with office_metadata module for core/app/custom properties.

Field	Type	Default	Description
`coreProperties`	`CoreProperties?`	`null`	Core properties from docProps/core.xml (Dublin Core metadata) Contains title, creator, subject, keywords, dates, etc. Shared format across DOCX/PPTX/XLSX documents.
`appProperties`	`DocxAppProperties?`	`null`	Application properties from docProps/app.xml (Word-specific statistics) Contains word count, page count, paragraph count, editing time, etc. DOCX-specific variant of Office application properties.
`customProperties`	`std.StringHashMap([:0]const u8)?`	`{}`	Custom properties from docProps/custom.xml (user-defined properties) Contains key-value pairs defined by users or applications. Values can be strings, numbers, booleans, or dates.

Element¶

Semantic element extracted from document.

Represents a logical unit of content with semantic classification, unique identifier, and metadata for tracking origin and position.

Field	Type	Default	Description
`elementId`	`[:0]const u8`	—	Unique element identifier
`elementType`	`ElementType`	—	Semantic type of this element
`text`	`[:0]const u8`	—	Text content of the element
`metadata`	`ElementMetadata`	—	Metadata about the element

ElementMetadata¶

Metadata for a semantic element.

Field	Type	Default	Description
`pageNumber`	`u32?`	`null`	Page number (1-indexed)
`filename`	`[:0]const u8?`	`null`	Source filename or document name
`coordinates`	`BoundingBox?`	`null`	Bounding box coordinates if available
`elementIndex`	`u64?`	`null`	Position index in the element sequence
`additional`	`std.StringHashMap([:0]const u8)`	—	Additional custom metadata

EmailAttachment¶

Email attachment representation.

Contains metadata and optionally the content of an email attachment.

Field	Type	Default	Description
`name`	`[:0]const u8?`	`null`	Attachment name (from Content-Disposition header)
`filename`	`[:0]const u8?`	`null`	Filename of the attachment
`mimeType`	`[:0]const u8?`	`null`	MIME type of the attachment
`size`	`u64?`	`null`	Size in bytes
`isImage`	`bool`	—	Whether this attachment is an image
`data`	`[]const u8?`	`null`	Attachment data (if extracted). Uses `bytes.Bytes` for cheap cloning of large buffers.

EmailConfig¶

Configuration for email extraction.

Field	Type	Default	Description
`msgFallbackCodepage`	`u32?`	`null`	Windows codepage number to use when an MSG file contains no codepage property. Defaults to `null`, which falls back to windows-1252. If an unrecognized or invalid codepage number is supplied (including 0), the behavior silently falls back to windows-1252 — the same as when the MSG file itself contains an unrecognized codepage. No error or warning is emitted. Users should verify output when supplying unusual values. Common values: - 1250: Central European (Polish, Czech, Hungarian, etc.) - 1251: Cyrillic (Russian, Ukrainian, Bulgarian, etc.) - 1252: Western European (default) - 1253: Greek - 1254: Turkish - 1255: Hebrew - 1256: Arabic - 932: Japanese (Shift-JIS) - 936: Simplified Chinese (GBK)

EmailExtractionResult¶

Email extraction result.

Complete representation of an extracted email message (.eml or .msg) including headers, body content, and attachments.

Field	Type	Default	Description
`subject`	`[:0]const u8?`	`null`	Email subject line
`fromEmail`	`[:0]const u8?`	`null`	Sender email address
`toEmails`	`[]const [:0]const u8`	—	Primary recipient email addresses
`ccEmails`	`[]const [:0]const u8`	—	CC recipient email addresses
`bccEmails`	`[]const [:0]const u8`	—	BCC recipient email addresses
`date`	`[:0]const u8?`	`null`	Email date/timestamp
`messageId`	`[:0]const u8?`	`null`	Message-ID header value
`plainText`	`[:0]const u8?`	`null`	Plain text version of the email body
`htmlContent`	`[:0]const u8?`	`null`	HTML version of the email body
`content`	`[:0]const u8`	—	Cleaned/processed text content. Aliased as `cleaned_text` for back-compat.
`attachments`	`[]const EmailAttachment`	—	List of email attachments
`metadata`	`std.StringHashMap([:0]const u8)`	—	Additional email headers and metadata

EmailMetadata¶

Email metadata extracted from .eml and .msg files.

Includes sender/recipient information, message ID, and attachment list.

Field	Type	Default	Description
`fromEmail`	`[:0]const u8?`	`null`	Sender's email address
`fromName`	`[:0]const u8?`	`null`	Sender's display name
`toEmails`	`[]const [:0]const u8`	`[]`	Primary recipients
`ccEmails`	`[]const [:0]const u8`	`[]`	CC recipients
`bccEmails`	`[]const [:0]const u8`	`[]`	BCC recipients
`messageId`	`[:0]const u8?`	`null`	Message-ID header value
`attachments`	`[]const [:0]const u8`	`[]`	List of attachment filenames

EmbeddedFile¶

Embedded file descriptor extracted from the PDF name tree.

Field	Type	Default	Description
`name`	`[:0]const u8`	—	The filename as stored in the PDF name tree.
`data`	`[]const u8`	—	Raw file bytes from the embedded stream.
`mimeType`	`[:0]const u8?`	`null`	MIME type if specified in the filespec, otherwise `null`.

EmbeddingBackend¶

Trait for in-process embedding backend plugins.

Async to match the convention used by OcrBackend, DocumentExtractor, and PostProcessor. Host-language bridges (PyO3, napi-rs, Rustler, extendr, magnus, ext-php-rs, C FFI, etc.) wrap their synchronous host callables in spawn_blocking or the equivalent to satisfy the async signature.

Thread safety¶

Backends must be Send + Sync + 'static. They are stored in Arc<dyn EmbeddingBackend> and called concurrently from kreuzberg's chunking pipeline. If the backend's underlying model isn't thread-safe, the backend itself must serialize access internally (e.g. via Mutex<Inner>).

Contract¶

embed(texts) MUST return exactly texts.len() vectors, each of length self.dimensions(). The dispatcher in embed_texts validates this before returning to downstream consumers; a non-conforming backend surfaces as a KreuzbergError.Validation, not a panic.
embed may be called from any thread. Its future must be Send (enforced by async_trait when #[async_trait] is used on non-WASM targets).
dimensions() is called exactly once at registration, immediately after initialize() succeeds. The returned value is cached by the registry and used for all subsequent shape validation. Lazy-loading implementations can defer model loading into initialize() and report the real dimension afterwards. Later mutations of the backend's reported dimension are not observed by kreuzberg — implementations that need to change dimension must unregister and re-register.
shutdown() (inherited from Plugin) may be invoked concurrently with an in-flight embed() call. Implementations must tolerate this — e.g. by letting in-flight calls finish using resources held via the Arc<dyn EmbeddingBackend> reference, and only releasing shared state that isn't needed by embed.

Runtime¶

The synchronous embed_texts entry uses tokio.task.block_in_place to await the trait's async embed, which requires a multi-thread tokio runtime. Callers running inside a current_thread runtime (e.g. #[tokio.test] without flavor = "multi_thread", or tokio.runtime.Builder.new_current_thread()) must use embed_texts_async instead, which awaits directly without block_in_place.

Methods¶

dimensions()¶

Embedding vector dimension. Must be > 0 and must match the length of every vector returned by embed.

Signature:

pub fn dimensions(self: *const EmbeddingBackend) u64

embed()¶

Embed a batch of texts, returning one vector per input in order.

Errors:

Implementations should return Plugin for backend-specific failures. The dispatcher layers its own validation (length, per-vector dimension) on top.

Signature:

pub fn embed(self: *const EmbeddingBackend, texts: []const [:0]const u8) Error![]const []const f32

EmbeddingConfig¶

Embedding configuration for text chunks.

Configures embedding generation using ONNX models via the vendored embedding engine. Requires the embeddings feature to be enabled.

Field	Type	Default	Description
`model`	`EmbeddingModelType`	`EmbeddingModelType.Preset`	The embedding model to use (defaults to "balanced" preset if not specified)
`normalize`	`bool`	`true`	Whether to normalize embedding vectors (recommended for cosine similarity)
`batchSize`	`u64`	`32`	Batch size for embedding generation
`showDownloadProgress`	`bool`	`false`	Show model download progress
`cacheDir`	`[:0]const u8?`	`null`	Custom cache directory for model files Defaults to `~/.cache/kreuzberg/embeddings/` if not specified. Allows full customization of model download location.
`acceleration`	`AccelerationConfig?`	`null`	Hardware acceleration for the embedding ONNX model. When set, controls which execution provider (CPU, CUDA, CoreML, TensorRT) is used for inference. Defaults to `null` (auto-select per platform).
`maxEmbedDurationSecs`	`u64?`	`null`	Maximum wall-clock duration (in seconds) for a single `embed()` call when using `EmbeddingModelType.Plugin`. Applies only to the in-process plugin path — protects against hung host-language backends (e.g. a Python callback deadlocked on the GIL, a model stuck on CUDA OOM retries, etc.). On timeout, the dispatcher returns `Plugin` instead of blocking forever. `null` disables the timeout. The default (60 seconds) is conservative for common in-process inference; increase for large batches on slow hardware.

Methods¶

default()¶

Signature:

pub fn default() EmbeddingConfig

EmbeddingPreset¶

Preset configurations for common RAG use cases.

Each preset combines chunk size, overlap, and embedding model to provide an optimized configuration for specific scenarios.

All string fields are owned String for FFI compatibility — instances are safe to clone and pass across language boundaries.

Field	Type	Default	Description
`name`	`[:0]const u8`	—	The name
`chunkSize`	`u64`	—	Chunk size
`overlap`	`u64`	—	Overlap
`modelRepo`	`[:0]const u8`	—	HuggingFace repository name for the model.
`pooling`	`[:0]const u8`	—	Pooling strategy: "cls" or "mean".
`modelFile`	`[:0]const u8`	—	Path to the ONNX model file within the repo.
`dimensions`	`u64`	—	Dimensions
`description`	`[:0]const u8`	—	Human-readable description

EpubMetadata¶

EPUB metadata (Dublin Core extensions).

Field	Type	Default	Description
`coverage`	`[:0]const u8?`	`null`	Coverage
`dcFormat`	`[:0]const u8?`	`null`	Dc format
`relation`	`[:0]const u8?`	`null`	Relation
`source`	`[:0]const u8?`	`null`	Source
`dcType`	`[:0]const u8?`	`null`	Dc type
`coverImage`	`[:0]const u8?`	`null`	Cover image

ErrorMetadata¶

Error metadata (for batch operations).

Field	Type	Default	Description
`errorType`	`[:0]const u8`	—	Error type
`message`	`[:0]const u8`	—	Message

ExcelMetadata¶

Excel/spreadsheet format metadata.

Identifies the document as a spreadsheet source via the FormatMetadata.Excel discriminant. Sheet count and sheet names are stored inside this struct.

Field	Type	Default	Description
`sheetCount`	`u32?`	`null`	Number of sheets in the workbook.
`sheetNames`	`[]const [:0]const u8?`	`[]`	Names of all sheets in the workbook.

ExcelSheet¶

Single Excel worksheet.

Represents one sheet from an Excel workbook with its content converted to Markdown format and dimensional statistics.

Field	Type	Default	Description
`name`	`[:0]const u8`	—	Sheet name as it appears in Excel
`markdown`	`[:0]const u8`	—	Sheet content converted to Markdown tables
`rowCount`	`u64`	—	Number of rows
`colCount`	`u64`	—	Number of columns
`cellCount`	`u64`	—	Total number of non-empty cells
`tableCells`	`[]const []const [:0]const u8?`	`null`	Pre-extracted table cells (2D vector of cell values) Populated during markdown generation to avoid re-parsing markdown. None for empty sheets.

ExcelWorkbook¶

Excel workbook representation.

Contains all sheets from an Excel file (.xlsx, .xls, etc.) with extracted content and metadata.

Field	Type	Default	Description
`sheets`	`[]const ExcelSheet`	—	All sheets in the workbook
`metadata`	`std.StringHashMap([:0]const u8)`	—	Workbook-level metadata (author, creation date, etc.)

ExtractedImage¶

Extracted image from a document.

Contains raw image data, metadata, and optional nested OCR results. Raw bytes allow cross-language compatibility - users can convert to PIL.Image (Python), Sharp (Node.js), or other formats as needed.

Field	Type	Default	Description
`data`	`[]const u8`	—	Raw image data (PNG, JPEG, WebP, etc. bytes). Uses `bytes.Bytes` for cheap cloning of large buffers.
`format`	`[:0]const u8`	—	Image format (e.g., "jpeg", "png", "webp") Uses Cow<'static, str> to avoid allocation for static literals.
`imageIndex`	`u32`	—	Zero-indexed position of this image in the document/page
`pageNumber`	`u32?`	`null`	Page/slide number where image was found (1-indexed)
`width`	`u32?`	`null`	Image width in pixels
`height`	`u32?`	`null`	Image height in pixels
`colorspace`	`[:0]const u8?`	`null`	Colorspace information (e.g., "RGB", "CMYK", "Gray")
`bitsPerComponent`	`u32?`	`null`	Bits per color component (e.g., 8, 16)
`isMask`	`bool`	`/* serde(default) */`	Whether this image is a mask image
`description`	`[:0]const u8?`	`null`	Optional description of the image
`ocrResult`	`ExtractionResult?`	`null`	Nested OCR extraction result (if image was OCRed) When OCR is performed on this image, the result is embedded here rather than in a separate collection, making the relationship explicit.
`boundingBox`	`BoundingBox?`	`/* serde(default) */`	Bounding box of the image on the page (PDF coordinates: x0=left, y0=bottom, x1=right, y1=top). Only populated for PDF-extracted images when position data is available from the PDF extractor.
`sourcePath`	`[:0]const u8?`	`/* serde(default) */`	Original source path of the image within the document archive (e.g., "media/image1.png" in DOCX). Used for rendering image references when the binary data is not extracted.
`imageKind`	`ImageKind?`	`/* serde(default) */`	Heuristic classification of what this image likely depicts. `null` if classification was disabled or inconclusive.
`kindConfidence`	`f32?`	`/* serde(default) */`	Confidence score for `image_kind`, in the range 0.0 to 1.0.
`clusterId`	`u32?`	`/* serde(default) */`	Identifier shared across images that form a single logical figure (e.g. all raster tiles of one technical drawing). `null` for singletons.

ExtractedImageMetadata¶

Image metadata extracted from an image file.

Field	Type	Default	Description
`width`	`u32`	—	Image width in pixels
`height`	`u32`	—	Image height in pixels
`format`	`[:0]const u8`	—	Image format (e.g., "PNG", "JPEG")
`exifData`	`std.StringHashMap([:0]const u8)`	—	EXIF data if available

ExtractionConfig¶

Main extraction configuration.

This struct contains all configuration options for the extraction process. It can be loaded from TOML, YAML, or JSON files, or created programmatically.

Field	Type	Default	Description
`useCache`	`bool`	`true`	Enable caching of extraction results
`enableQualityProcessing`	`bool`	`true`	Enable quality post-processing
`ocr`	`OcrConfig?`	`null`	OCR configuration (None = OCR disabled)
`forceOcr`	`bool`	`false`	Force OCR even for searchable PDFs
`forceOcrPages`	`[]const u32?`	`null`	Force OCR on specific pages only (1-indexed page numbers, must be >= 1). When set, only the listed pages are OCR'd regardless of text layer quality. Unlisted pages use native text extraction. Ignored when `force_ocr` is `true`. Only applies to PDF documents. Duplicates are automatically deduplicated. An `ocr` config is recommended for backend/language selection; defaults are used if absent.
`disableOcr`	`bool`	`false`	Disable OCR entirely, even for images. When `true`, OCR is skipped for all document types. Images return metadata only (dimensions, format, EXIF) without text extraction. PDFs use only native text extraction without OCR fallback. Cannot be `true` simultaneously with `force_ocr`. Added in v4.7.0.
`chunking`	`ChunkingConfig?`	`null`	Text chunking configuration (None = chunking disabled)
`contentFilter`	`ContentFilterConfig?`	`null`	Content filtering configuration (None = use extractor defaults). Controls whether document "furniture" (headers, footers, watermarks, repeating text) is included in or stripped from extraction results. See `ContentFilterConfig` for per-field documentation.
`images`	`ImageExtractionConfig?`	`null`	Image extraction configuration (None = no image extraction)
`pdfOptions`	`PdfConfig?`	`null`	PDF-specific options (None = use defaults)
`tokenReduction`	`TokenReductionOptions?`	`null`	Token reduction configuration (None = no token reduction)
`languageDetection`	`LanguageDetectionConfig?`	`null`	Language detection configuration (None = no language detection)
`pages`	`PageConfig?`	`null`	Page extraction configuration (None = no page tracking)
`keywords`	`KeywordConfig?`	`null`	Keyword extraction configuration (None = no keyword extraction)
`postprocessor`	`PostProcessorConfig?`	`null`	Post-processor configuration (None = use defaults)
`htmlOptions`	`[:0]const u8?`	`null`	HTML to Markdown conversion options (None = use defaults) Configure how HTML documents are converted to Markdown, including heading styles, list formatting, code block styles, and preprocessing options.
`htmlOutput`	`HtmlOutputConfig?`	`null`	Styled HTML output configuration. When set alongside `output_format = OutputFormat.Html`, the extraction pipeline uses `StyledHtmlRenderer` which emits stable `kb-*` CSS class hooks on every structural element and optionally embeds theme CSS or user-supplied CSS in a `<style>` block. When `null`, the existing plain comrak-based HTML renderer is used.
`extractionTimeoutSecs`	`u64?`	`null`	Default per-file timeout in seconds for batch extraction. When set, each file in a batch will be canceled after this duration unless overridden by `FileExtractionConfig.timeout_secs`. `null` means no timeout (unbounded extraction time).
`maxConcurrentExtractions`	`u64?`	`null`	Maximum concurrent extractions in batch operations (None = (num_cpus × 1.5).ceil()). Limits parallelism to prevent resource exhaustion when processing large batches. Defaults to (num_cpus × 1.5).ceil() when not set.
`resultFormat`	`ResultFormat`	`ResultFormat.Unified`	Result structure format Controls whether results are returned in unified format (default) with all content in the `content` field, or element-based format with semantic elements (for Unstructured-compatible output).
`securityLimits`	`SecurityLimits?`	`null`	Security limits for archive extraction. Controls maximum archive size, compression ratio, file count, and other security thresholds to prevent decompression bomb attacks. Also caps nesting depth, iteration count, entity / token length, total content size, and table cell count for every extraction path that ingests user-controlled bytes. When `null`, default limits are used.
`outputFormat`	`OutputFormat`	`OutputFormat.Plain`	Content text format (default: Plain). Controls the format of the extracted content: - `Plain`: Raw extracted text (default) - `Markdown`: Markdown formatted output - `Djot`: Djot markup format (requires djot feature) - `Html`: HTML formatted output When set to a structured format, extraction results will include formatted output. The `formatted_content` field may be populated when format conversion is applied.
`layout`	`LayoutDetectionConfig?`	`null`	Layout detection configuration (None = layout detection disabled). When set, PDF pages and images are analyzed for document structure (headings, code, formulas, tables, figures, etc.) using RT-DETR models via ONNX Runtime. For PDFs, layout hints override paragraph classification in the markdown pipeline. For images, per-region OCR is performed with markdown formatting based on detected layout classes. Requires the `layout-detection` feature to run inference; the field is present whenever the `layout-types` feature is active (which includes `layout-detection` as well as the no-ORT target groups).
`useLayoutForMarkdown`	`bool`	`false`	Run layout detection on the non-OCR PDF markdown path. When `true` and `layout` is `Some(_)`, layout regions inform heading, table, list, and figure detection in the structure pipeline that would otherwise rely on font-clustering heuristics alone. Significantly improves SF1 (structural F1) at the cost of inference latency (~150-300ms/page CPU, ~20-50ms/page GPU). Default: `false`. Requires the `layout-detection` feature.
`includeDocumentStructure`	`bool`	`false`	Enable structured document tree output. When true, populates the `document` field on `ExtractionResult` with a hierarchical `DocumentStructure` containing heading-driven section nesting, table grids, content layer classification, and inline annotations. Independent of `result_format` — can be combined with Unified or ElementBased.
`acceleration`	`AccelerationConfig?`	`null`	Hardware acceleration configuration for ONNX Runtime models. Controls execution provider selection for layout detection and embedding models. When `null`, uses platform defaults (CoreML on macOS, CUDA on Linux, CPU on Windows).
`cacheNamespace`	`[:0]const u8?`	`null`	Cache namespace for tenant isolation. When set, cache entries are stored under `{cache_dir}/{namespace}/`. Must be alphanumeric, hyphens, or underscores only (max 64 chars). Different namespaces have isolated cache spaces on the same filesystem.
`cacheTtlSecs`	`u64?`	`null`	Per-request cache TTL in seconds. Overrides the global `max_age_days` for this specific extraction. When `0`, caching is completely skipped (no read or write). When `null`, the global TTL applies.
`email`	`EmailConfig?`	`null`	Email extraction configuration (None = use defaults). Currently supports configuring the fallback codepage for MSG files that do not specify one. See `EmailConfig` for details.
`concurrency`	`[:0]const u8?`	`null`	Concurrency limits for constrained environments (None = use defaults). Controls Rayon thread pool size, ONNX Runtime intra-op threads, and (when `max_concurrent_extractions` is unset) the batch concurrency semaphore. See `ConcurrencyConfig` for details.
`maxArchiveDepth`	`u64`	—	Maximum recursion depth for archive extraction (default: 3). Set to 0 to disable recursive extraction (legacy behavior).
`treeSitter`	`TreeSitterConfig?`	`null`	Tree-sitter language pack configuration (None = tree-sitter disabled). When set, enables code file extraction using tree-sitter parsers. Controls grammar download behavior and code analysis options.
`structuredExtraction`	`StructuredExtractionConfig?`	`null`	Structured extraction via LLM (None = disabled). When set, the extracted document content is sent to an LLM with the provided JSON schema. The structured response is stored in `ExtractionResult.structured_output`.
`cancelToken`	`[:0]const u8?`	`null`	Cancellation token for this extraction (None = no external cancellation). Pass a `CancellationToken` clone here and call `CancellationToken.cancel` from another thread / task to abort the extraction in progress. The extractor checks the token at safe checkpoints (before lock acquisition, between pages, between batch items) and returns `KreuzbergError.Cancelled` when set. The field is excluded from serialization because `CancellationToken` is a runtime handle, not a configuration value.

Methods¶

default()¶

Signature:

pub fn default() ExtractionConfig

needsImageProcessing()¶

Check if image processing is needed by examining OCR and image extraction settings.

Returns true if either OCR is enabled or image extraction is configured, indicating that image decompression and processing should occur. Returns false if both are disabled, allowing optimization to skip unnecessary image decompression for text-only extraction workflows.

Optimization Impact¶

For text-only extractions (no OCR, no image extraction), skipping image decompression can improve CPU utilization by 5-10% by avoiding wasteful image I/O and processing when results won't be used.

Signature:

pub fn needsImageProcessing(self: *const ExtractionConfig) bool

ExtractionResult¶

General extraction result used by the core extraction API.

This is the main result type returned by all extraction functions.

Field	Type	Default	Description
`content`	`[:0]const u8`	—	The extracted text content
`mimeType`	`[:0]const u8`	—	The detected MIME type
`metadata`	`Metadata`	—	Document metadata
`extractionMethod`	`ExtractionMethod?`	`null`	Extraction strategy used to produce the returned text. Populated when the extractor can reliably distinguish native text extraction, OCR-only extraction, or mixed native/OCR output.
`tables`	`[]const Table`	`[]`	Tables extracted from the document
`detectedLanguages`	`[]const [:0]const u8?`	`[]`	Detected languages
`chunks`	`[]const Chunk?`	`[]`	Text chunks when chunking is enabled. When chunking configuration is provided, the content is split into overlapping chunks for efficient processing. Each chunk contains the text, optional embeddings (if enabled), and metadata about its position.
`images`	`[]const ExtractedImage?`	`[]`	Extracted images from the document. When image extraction is enabled via `ImageExtractionConfig`, this field contains all images found in the document with their raw data and metadata. Each image may optionally contain a nested `ocr_result` if OCR was performed.
`pages`	`[]const PageContent?`	`[]`	Per-page content when page extraction is enabled. When page extraction is configured, the document is split into per-page content with tables and images mapped to their respective pages.
`elements`	`[]const Element?`	`[]`	Semantic elements when element-based result format is enabled. When result_format is set to ElementBased, this field contains semantic elements with type classification, unique identifiers, and metadata for Unstructured-compatible element-based processing.
`djotContent`	`DjotContent?`	`null`	Rich Djot content structure (when extracting Djot documents). When extracting Djot documents with structured extraction enabled, this field contains the full semantic structure including: - Block-level elements with nesting - Inline formatting with attributes - Links, images, footnotes - Math expressions - Complete attribute information The `content` field still contains plain text for backward compatibility. Always `null` for non-Djot documents.
`ocrElements`	`[]const OcrElement?`	`[]`	OCR elements with full spatial and confidence metadata. When OCR is performed with element extraction enabled, this field contains the structured representation of detected text including: - Bounding geometry (rectangles or quadrilaterals) - Confidence scores (detection and recognition) - Rotation information - Hierarchical relationships (Tesseract only) This field preserves all metadata that would otherwise be lost when converting to plain text or markdown output formats. Only populated when `OcrElementConfig.include_elements` is true.
`document`	`DocumentStructure?`	`null`	Structured document tree (when document structure extraction is enabled). When `include_document_structure` is true in `ExtractionConfig`, this field contains the full hierarchical representation of the document including: - Heading-driven section nesting - Table grids with cell-level metadata - Content layer classification (body, header, footer, footnote) - Inline text annotations (formatting, links) - Bounding boxes and page numbers Independent of `result_format` — can be combined with Unified or ElementBased.
`extractedKeywords`	`[]const Keyword?`	`[]`	Extracted keywords when keyword extraction is enabled. When keyword extraction (RAKE or YAKE) is configured, this field contains the extracted keywords with scores, algorithm info, and position data. Previously stored in `metadata.additional["keywords"]`.
`qualityScore`	`f64?`	`null`	Document quality score from quality analysis. A value between 0.0 and 1.0 indicating the overall text quality. Previously stored in `metadata.additional["quality_score"]`.
`processingWarnings`	`[]const ProcessingWarning`	`[]`	Non-fatal warnings collected during processing pipeline stages. Captures errors from optional pipeline features (embedding, chunking, language detection, output formatting) that don't prevent extraction but may indicate degraded results. Previously stored as individual keys in `metadata.additional`.
`annotations`	`[]const PdfAnnotation?`	`[]`	PDF annotations extracted from the document. When annotation extraction is enabled via `PdfConfig.extract_annotations`, this field contains text notes, highlights, links, stamps, and other annotations found in PDF documents.
`children`	`[]const ArchiveEntry?`	`[]`	Nested extraction results from archive contents. When extracting archives, each processable file inside produces its own full extraction result. Set to `null` for non-archive formats. Use `max_archive_depth` in config to control recursion depth.
`uris`	`[]const Uri?`	`[]`	URIs/links discovered during document extraction. Contains hyperlinks, image references, citations, email addresses, and other URI-like references found in the document. Always extracted when present in the source document.
`structuredOutput`	`[:0]const u8?`	`null`	Structured extraction output from LLM-based JSON schema extraction. When `structured_extraction` is configured in `ExtractionConfig`, the extracted document content is sent to a VLM with the provided JSON schema. The response is parsed and stored here as a JSON value matching the schema.
`codeIntelligence`	`[:0]const u8?`	`null`	Code intelligence results from tree-sitter analysis. Populated when extracting source code files with the `tree-sitter` feature. Contains metrics, structural analysis, imports/exports, comments, docstrings, symbols, diagnostics, and optionally chunked code segments. Stored as an opaque JSON value so that all language bindings (Go, Java, C#, …) can deserialize it as a raw JSON object rather than a typed struct. The underlying type is `tree_sitter_language_pack.ProcessResult`.
`llmUsage`	`[]const LlmUsage?`	`[]`	LLM token usage and cost data for all LLM calls made during this extraction. Contains one entry per LLM call. Multiple entries are produced when VLM OCR, structured extraction, or LLM embeddings run during the same extraction. `null` when no LLM was used.
`formattedContent`	`[:0]const u8?`	`null`	Pre-rendered content in the requested output format. Populated during `derive_extraction_result` before tree derivation consumes element data. `apply_output_format` swaps this into `content` at the end of the pipeline, after post-processors have operated on plain text.
`ocrInternalDocument`	`[:0]const u8?`	`null`	Structured hOCR document for the OCR+layout pipeline. When tesseract produces hOCR output, the parsed `InternalDocument` carries paragraph structure with bounding boxes and confidence scores. The layout classification step enriches these elements before final rendering.

Methods¶

fromOcr()¶

Convert from an OCR result.

Signature:

pub fn fromOcr(ocr: OcrExtractionResult) ExtractionResult

FictionBookMetadata¶

FictionBook (FB2) metadata.

Field	Type	Default	Description
`genres`	`[]const [:0]const u8`	`[]`	Genres
`sequences`	`[]const [:0]const u8`	`[]`	Sequences
`annotation`	`[:0]const u8?`	`null`	Annotation

FileExtractionConfig¶

Per-file extraction configuration overrides for batch processing.

All fields are Option<T> — null means "use the batch-level default." This type is used with batch_extract_files and batch_extract_bytes to allow heterogeneous extraction settings within a single batch.

Excluded Fields¶

The following ExtractionConfig fields are batch-level only and cannot be overridden per file:

max_concurrent_extractions — controls batch parallelism
use_cache — global caching policy
acceleration — shared ONNX execution provider
security_limits — global archive security policy

Field	Type	Default	Description
`enableQualityProcessing`	`bool?`	`null`	Override quality post-processing for this file.
`ocr`	`OcrConfig?`	`null`	Override OCR configuration for this file (None in the Option = use batch default).
`forceOcr`	`bool?`	`null`	Override force OCR for this file.
`forceOcrPages`	`[]const u32?`	`[]`	Override force OCR pages for this file (1-indexed page numbers).
`disableOcr`	`bool?`	`null`	Override disable OCR for this file.
`chunking`	`ChunkingConfig?`	`null`	Override chunking configuration for this file.
`contentFilter`	`ContentFilterConfig?`	`null`	Override content filtering configuration for this file.
`images`	`ImageExtractionConfig?`	`null`	Override image extraction configuration for this file.
`pdfOptions`	`PdfConfig?`	`null`	Override PDF options for this file.
`tokenReduction`	`TokenReductionOptions?`	`null`	Override token reduction for this file.
`languageDetection`	`LanguageDetectionConfig?`	`null`	Override language detection for this file.
`pages`	`PageConfig?`	`null`	Override page extraction for this file.
`keywords`	`KeywordConfig?`	`null`	Override keyword extraction for this file.
`postprocessor`	`PostProcessorConfig?`	`null`	Override post-processor for this file.
`htmlOptions`	`[:0]const u8?`	`null`	Override HTML conversion options for this file.
`resultFormat`	`ResultFormat?`	`null`	Override result format for this file.
`outputFormat`	`OutputFormat?`	`null`	Override output content format for this file.
`includeDocumentStructure`	`bool?`	`null`	Override document structure output for this file.
`layout`	`LayoutDetectionConfig?`	`null`	Override layout detection for this file.
`timeoutSecs`	`u64?`	`null`	Override per-file extraction timeout in seconds. When set, the extraction for this file will be canceled after the specified duration. A timed-out file produces an error result without affecting other files in the batch.
`treeSitter`	`TreeSitterConfig?`	`null`	Override tree-sitter configuration for this file.
`structuredExtraction`	`StructuredExtractionConfig?`	`null`	Override structured extraction configuration for this file. When set, enables LLM-based structured extraction with a JSON schema for this specific file. The extracted content is sent to a VLM/LLM and the response is parsed according to the provided schema.

Footnote¶

Footnote in Djot.

Field	Type	Default	Description
`label`	`[:0]const u8`	—	Footnote label
`content`	`[]const FormattedBlock`	—	Footnote content blocks

FormattedBlock¶

Block-level element in a Djot document.

Represents structural elements like headings, paragraphs, lists, code blocks, etc.

Field	Type	Default	Description
`blockType`	`BlockType`	—	Type of block element
`level`	`u64?`	`null`	Heading level (1-6) for headings, or nesting level for lists
`inlineContent`	`[]const InlineElement`	—	Inline content within the block
`attributes`	`[:0]const u8?`	`null`	Element attributes (classes, IDs, key-value pairs)
`language`	`[:0]const u8?`	`null`	Language identifier for code blocks
`code`	`[:0]const u8?`	`null`	Raw code content for code blocks
`children`	`[]const FormattedBlock`	`/* serde(default) */`	Nested blocks for containers (blockquotes, list items, divs)

GridCell¶

Individual grid cell with position and span metadata.

Field	Type	Default	Description
`content`	`[:0]const u8`	—	Cell text content.
`row`	`u32`	—	Zero-indexed row position.
`col`	`u32`	—	Zero-indexed column position.
`rowSpan`	`u32`	`/* serde(default) */`	Number of rows this cell spans.
`colSpan`	`u32`	`/* serde(default) */`	Number of columns this cell spans.
`isHeader`	`bool`	`/* serde(default) */`	Whether this is a header cell.
`bbox`	`BoundingBox?`	`null`	Bounding box for this cell (if available).

HeaderMetadata¶

Header/heading element metadata.

Field	Type	Default	Description
`level`	`u8`	—	Header level: 1 (h1) through 6 (h6)
`text`	`[:0]const u8`	—	Normalized text content of the header
`id`	`[:0]const u8?`	`null`	HTML id attribute if present
`depth`	`u32`	—	Document tree depth at the header element
`htmlOffset`	`u32`	—	Byte offset in original HTML document

HeadingContext¶

Heading context for a chunk within a Markdown document.

Contains the heading hierarchy from document root to this chunk's section.

Field	Type	Default	Description
`headings`	`[]const HeadingLevel`	—	The heading hierarchy from document root to this chunk's section. Index 0 is the outermost (h1), last element is the most specific.

HeadingLevel¶

A single heading in the hierarchy.

Field	Type	Default	Description
`level`	`u8`	—	Heading depth (1 = h1, 2 = h2, etc.)
`text`	`[:0]const u8`	—	The text content of the heading.

HierarchicalBlock¶

A text block with hierarchy level assignment.

Represents a block of text with semantic heading information extracted from font size clustering and hierarchical analysis.

Field	Type	Default	Description
`text`	`[:0]const u8`	—	The text content of this block
`fontSize`	`f32`	—	The font size of the text in this block
`level`	`[:0]const u8`	—	The hierarchy level of this block (H1-H6 or Body) Levels correspond to HTML heading tags: - "h1": Top-level heading - "h2": Secondary heading - "h3": Tertiary heading - "h4": Quaternary heading - "h5": Quinary heading - "h6": Senary heading - "body": Body text (no heading level)
`bbox`	`[]const f32?`	`null`	Bounding box information for the block Contains coordinates as (left, top, right, bottom) in PDF units.

HierarchyConfig¶

Hierarchy extraction configuration for PDF text structure analysis.

Enables extraction of document hierarchy levels (H1-H6) based on font size clustering and semantic analysis. When enabled, hierarchical blocks are included in page content.

Field	Type	Default	Description
`enabled`	`bool`	`true`	Enable hierarchy extraction
`kClusters`	`u64`	`3`	Number of font size clusters to use for hierarchy levels (1-7) Default: 6, which provides H1-H6 heading levels with body text. Larger values create more fine-grained hierarchy levels.
`includeBbox`	`bool`	`true`	Include bounding box information in hierarchy blocks
`ocrCoverageThreshold`	`f32?`	`null`	OCR coverage threshold for smart OCR triggering (0.0-1.0) Determines when OCR should be triggered based on text block coverage. OCR is triggered when text blocks cover less than this fraction of the page. Default: 0.5 (trigger OCR if less than 50% of page has text)

Methods¶

default()¶

Signature:

pub fn default() HierarchyConfig

HtmlMetadata¶

HTML metadata extracted from HTML documents.

Includes document-level metadata, Open Graph data, Twitter Card metadata, and extracted structural elements (headers, links, images, structured data).

Field	Type	Default	Description
`title`	`[:0]const u8?`	`null`	Document title from `<title>` tag
`description`	`[:0]const u8?`	`null`	Document description from `<meta name="description">` tag
`keywords`	`[]const [:0]const u8`	`[]`	Document keywords from `<meta name="keywords">` tag, split on commas
`author`	`[:0]const u8?`	`null`	Document author from `<meta name="author">` tag
`canonicalUrl`	`[:0]const u8?`	`null`	Canonical URL from `<link rel="canonical">` tag
`baseHref`	`[:0]const u8?`	`null`	Base URL from `<base href="">` tag for resolving relative URLs
`language`	`[:0]const u8?`	`null`	Document language from `lang` attribute
`textDirection`	`TextDirection?`	`null`	Document text direction from `dir` attribute
`openGraph`	`std.StringHashMap([:0]const u8)`	`{}`	Open Graph metadata (og:* properties) for social media Keys like "title", "description", "image", "url", etc.
`twitterCard`	`std.StringHashMap([:0]const u8)`	`{}`	Twitter Card metadata (twitter:* properties) Keys like "card", "site", "creator", "title", "description", "image", etc.
`metaTags`	`std.StringHashMap([:0]const u8)`	`{}`	Additional meta tags not covered by specific fields Keys are meta name/property attributes, values are content
`headers`	`[]const HeaderMetadata`	`[]`	Extracted header elements with hierarchy
`links`	`[]const LinkMetadata`	`[]`	Extracted hyperlinks with type classification
`images`	`[]const ImageMetadataType`	`[]`	Extracted images with source and dimensions
`structuredData`	`[]const StructuredData`	`[]`	Extracted structured data blocks

HtmlOutputConfig¶

Configuration for styled HTML output.

When set on ExtractionConfig.html_output alongside output_format = OutputFormat.Html, the pipeline builds a StyledHtmlRenderer instead of the plain comrak-based renderer.

Field	Type	Default	Description
`css`	`[:0]const u8?`	`null`	Inline CSS string injected into the output after the theme stylesheet. Concatenated after `css_file` content when both are set.
`cssFile`	`[:0]const u8?`	`null`	Path to a CSS file loaded once at renderer construction time. Concatenated before `css` when both are set.
`theme`	`HtmlTheme`	`HtmlTheme.Unstyled`	Built-in colour/typography theme. Default: `HtmlTheme.Unstyled`.
`classPrefix`	`[:0]const u8`	—	CSS class prefix applied to every emitted class name. Default: `"kb-"`. Change this if your host application already uses classes that start with `kb-`.
`embedCss`	`bool`	`true`	When `true` (default), write the resolved CSS into a `<style>` block immediately after the opening `<div class="{prefix}doc">`. Set to `false` to emit only the structural markup and wire up your own stylesheet targeting the `kb-*` class names.

Methods¶

default()¶

Signature:

pub fn default() HtmlOutputConfig

ImageExtractionConfig¶

Image extraction configuration.

Field	Type	Default	Description
`extractImages`	`bool`	`true`	Extract images from documents
`targetDpi`	`i32`	`300`	Target DPI for image normalization
`maxImageDimension`	`i32`	`4096`	Maximum dimension for images (width or height)
`injectPlaceholders`	`bool`	`true`	Whether to inject image reference placeholders into markdown output. When `true` (default), image references like `![Image 1](embedded:p1_i0)` are appended to the markdown. Set to `false` to extract images as data without polluting the markdown output.
`autoAdjustDpi`	`bool`	`true`	Automatically adjust DPI based on image content
`minDpi`	`i32`	`72`	Minimum DPI threshold
`maxDpi`	`i32`	`600`	Maximum DPI threshold
`maxImagesPerPage`	`u32?`	`null`	Maximum number of image objects to extract per PDF page. Some PDFs (e.g. technical diagrams stored as thousands of raster fragments) can trigger extremely long or indefinite extraction times when every image object on a dense page is decoded individually via the PDF extractor. Setting this limit causes kreuzberg to stop collecting individual images once the count per page reaches the cap and emit a warning instead. `null` (default) means no limit — all images are extracted.
`classify`	`bool`	`true`	When `true` (default), extracted images are classified by kind and grouped into clusters where they appear to belong to one figure.

Methods¶

default()¶

Signature:

pub fn default() ImageExtractionConfig

ImageMetadata¶

Image metadata extracted from image files.

Includes dimensions, format, and EXIF data.

Field	Type	Default	Description
`width`	`u32`	—	Image width in pixels
`height`	`u32`	—	Image height in pixels
`format`	`[:0]const u8`	—	Image format (e.g., "PNG", "JPEG", "TIFF")
`exif`	`std.StringHashMap([:0]const u8)`	`{}`	EXIF metadata tags

ImageMetadataType¶

Image element metadata.

Field	Type	Default	Description
`src`	`[:0]const u8`	—	Image source (URL, data URI, or SVG content)
`alt`	`[:0]const u8?`	`null`	Alternative text from alt attribute
`title`	`[:0]const u8?`	`null`	Title attribute
`dimensions`	`[]const u32?`	`null`	Image dimensions as (width, height) if available
`imageType`	`ImageType`	—	Image type classification
`attributes`	`[]const []const [:0]const u8`	—	Additional attributes as key-value pairs

ImagePreprocessingConfig¶

Image preprocessing configuration for OCR.

These settings control how images are preprocessed before OCR to improve text recognition quality. Different preprocessing strategies work better for different document types.

Field	Type	Default	Description
`targetDpi`	`i32`	`300`	Target DPI for the image (300 is standard, 600 for small text).
`autoRotate`	`bool`	`true`	Auto-detect and correct image rotation.
`deskew`	`bool`	`true`	Correct skew (tilted images).
`denoise`	`bool`	`false`	Remove noise from the image.
`contrastEnhance`	`bool`	`false`	Enhance contrast for better text visibility.
`binarizationMethod`	`[:0]const u8`	`"otsu"`	Binarization method: "otsu", "sauvola", "adaptive".
`invertColors`	`bool`	`false`	Invert colors (white text on black → black on white).

Methods¶

default()¶

Signature:

pub fn default() ImagePreprocessingConfig

ImagePreprocessingMetadata¶

Image preprocessing metadata.

Tracks the transformations applied to an image during OCR preprocessing, including DPI normalization, resizing, and resampling.

Field	Type	Default	Description
`originalDimensions`	`[]const u64`	—	Original image dimensions (width, height) in pixels
`originalDpi`	`[]const f64`	—	Original image DPI (horizontal, vertical)
`targetDpi`	`i32`	—	Target DPI from configuration
`scaleFactor`	`f64`	—	Scaling factor applied to the image
`autoAdjusted`	`bool`	—	Whether DPI was auto-adjusted based on content
`finalDpi`	`i32`	—	Final DPI after processing
`newDimensions`	`[]const u64?`	`null`	New dimensions after resizing (if resized)
`resampleMethod`	`[:0]const u8`	—	Resampling algorithm used ("LANCZOS3", "CATMULLROM", etc.)
`dimensionClamped`	`bool`	—	Whether dimensions were clamped to max_image_dimension
`calculatedDpi`	`i32?`	`null`	Calculated optimal DPI (if auto_adjust_dpi enabled)
`skippedResize`	`bool`	—	Whether resize was skipped (dimensions already optimal)
`resizeError`	`[:0]const u8?`	`null`	Error message if resize failed

InlineElement¶

Inline element within a block.

Represents text with formatting, links, images, etc.

Field	Type	Default	Description
`elementType`	`InlineType`	—	Type of inline element
`content`	`[:0]const u8`	—	Text content
`attributes`	`[:0]const u8?`	`null`	Element attributes
`metadata`	`std.StringHashMap([:0]const u8)?`	`null`	Additional metadata (e.g., href for links, src/alt for images)

JatsMetadata¶

JATS (Journal Article Tag Suite) metadata.

Field	Type	Default	Description
`copyright`	`[:0]const u8?`	`null`	Copyright
`license`	`[:0]const u8?`	`null`	License
`historyDates`	`std.StringHashMap([:0]const u8)`	`{}`	History dates
`contributorRoles`	`[]const ContributorRole`	`[]`	Contributor roles

Keyword¶

Extracted keyword with metadata.

Field	Type	Default	Description
`text`	`[:0]const u8`	—	The keyword text.
`score`	`f32`	—	Relevance score (higher is better, algorithm-specific range).
`algorithm`	`KeywordAlgorithm`	—	Algorithm that extracted this keyword.
`positions`	`[]const u64?`	`null`	Optional positions where keyword appears in text (character offsets).

KeywordConfig¶

Keyword extraction configuration.

Field	Type	Default	Description
`algorithm`	`KeywordAlgorithm`	`KeywordAlgorithm.Yake`	Algorithm to use for extraction.
`maxKeywords`	`u64`	`10`	Maximum number of keywords to extract (default: 10).
`minScore`	`f32`	`0`	Minimum score threshold (0.0-1.0, default: 0.0). Keywords with scores below this threshold are filtered out. Note: Score ranges differ between algorithms.
`ngramRange`	`[]const u64`	`[]`	N-gram range for keyword extraction (min, max). (1, 1) = unigrams only (1, 2) = unigrams and bigrams (1, 3) = unigrams, bigrams, and trigrams (default)
`language`	`[:0]const u8?`	`null`	Language code for stopword filtering (e.g., "en", "de", "fr"). If None, no stopword filtering is applied.
`yakeParams`	`YakeParams?`	`null`	YAKE-specific tuning parameters.
`rakeParams`	`RakeParams?`	`null`	RAKE-specific tuning parameters.

Methods¶

default()¶

Signature:

pub fn default() KeywordConfig

LanguageDetectionConfig¶

Language detection configuration.

Field	Type	Default	Description
`enabled`	`bool`	`true`	Enable language detection
`minConfidence`	`f64`	`0.8`	Minimum confidence threshold (0.0-1.0)
`detectMultiple`	`bool`	`false`	Detect multiple languages in the document

Methods¶

default()¶

Signature:

pub fn default() LanguageDetectionConfig

LayoutDetection¶

A single layout detection result.

Field	Type	Default	Description
`className`	`LayoutClass`	—	Class name (layout class)
`confidence`	`f32`	—	Confidence
`bbox`	`BBox`	—	Bbox (b box)

LayoutDetectionConfig¶

Layout detection configuration.

Controls layout detection behavior in the extraction pipeline. When set on ExtractionConfig, layout detection is enabled for PDF extraction.

Field	Type	Default	Description
`confidenceThreshold`	`f32?`	`null`	Confidence threshold override (None = use model default).
`applyHeuristics`	`bool`	`true`	Whether to apply postprocessing heuristics (default: true).
`tableModel`	`TableModel`	`TableModel.Tatr`	Table structure recognition model. Controls which model is used for table cell detection within layout-detected table regions. Defaults to `TableModel.Tatr`.
`acceleration`	`AccelerationConfig?`	`null`	Hardware acceleration for ONNX models (layout detection + table structure). When set, controls which execution provider (CPU, CUDA, CoreML, TensorRT) is used for inference. Defaults to `null` (auto-select per platform).

Methods¶

default()¶

Signature:

pub fn default() LayoutDetectionConfig

LayoutRegion¶

A detected layout region on a page.

When layout detection is enabled, each page may have layout regions identifying different content types (text, pictures, tables, etc.) with confidence scores and spatial positions.

Field	Type	Default	Description
`className`	`[:0]const u8`	—	Layout class name (e.g. "picture", "table", "text", "section_header").
`confidence`	`f64`	—	Confidence score from the layout detection model (0.0 to 1.0).
`boundingBox`	`BoundingBox`	—	Bounding box in document coordinate space.
`areaFraction`	`f64`	—	Fraction of the page area covered by this region (0.0 to 1.0).

LinkMetadata¶

Link element metadata.

Field	Type	Default	Description
`href`	`[:0]const u8`	—	The href URL value
`text`	`[:0]const u8`	—	Link text content (normalized)
`title`	`[:0]const u8?`	`null`	Optional title attribute
`linkType`	`LinkType`	—	Link type classification
`rel`	`[]const [:0]const u8`	—	Rel attribute values
`attributes`	`[]const []const [:0]const u8`	—	Additional attributes as key-value pairs

LlmConfig¶

Configuration for an LLM provider/model via liter-llm.

Each feature (VLM OCR, VLM embeddings, structured extraction) carries its own LlmConfig, allowing different providers per feature.

Field	Type	Default	Description
`model`	`[:0]const u8`	—	Provider/model string using liter-llm routing format. Examples: `"openai/gpt-4o"`, `"anthropic/claude-sonnet-4-20250514"`, `"groq/llama-3.1-70b-versatile"`.
`apiKey`	`[:0]const u8?`	`null`	API key for the provider. When `null`, liter-llm falls back to the provider's standard environment variable (e.g., `OPENAI_API_KEY`).
`baseUrl`	`[:0]const u8?`	`null`	Custom base URL override for the provider endpoint.
`timeoutSecs`	`u64?`	`null`	Request timeout in seconds (default: 60).
`maxRetries`	`u32?`	`null`	Maximum retry attempts (default: 3).
`temperature`	`f64?`	`null`	Sampling temperature for generation tasks.
`maxTokens`	`u64?`	`null`	Maximum tokens to generate.

LlmUsage¶

Token usage and cost data for a single LLM call made during extraction.

Populated when VLM OCR, structured extraction, or LLM-based embeddings are used. Multiple entries may be present when multiple LLM calls occur within one extraction (e.g. VLM OCR + structured extraction).

Field	Type	Default	Description
`model`	`[:0]const u8`	—	The LLM model identifier (e.g. "openai/gpt-4o", "anthropic/claude-sonnet-4-20250514").
`source`	`[:0]const u8`	—	The pipeline stage that triggered this LLM call (e.g. "vlm_ocr", "structured_extraction", "embeddings").
`inputTokens`	`u64?`	`null`	Number of input/prompt tokens consumed.
`outputTokens`	`u64?`	`null`	Number of output/completion tokens generated.
`totalTokens`	`u64?`	`null`	Total tokens (input + output).
`estimatedCost`	`f64?`	`null`	Estimated cost in USD based on the provider's published pricing.
`finishReason`	`[:0]const u8?`	`null`	Why the model stopped generating (e.g. "stop", "length", "content_filter").

Metadata¶

Extraction result metadata.

Contains common fields applicable to all formats, format-specific metadata via a discriminated union, and additional custom fields from postprocessors.

Field	Type	Default	Description
`title`	`[:0]const u8?`	`null`	Document title
`subject`	`[:0]const u8?`	`null`	Document subject or description
`authors`	`[]const [:0]const u8?`	`[]`	Primary author(s) - always Vec for consistency
`keywords`	`[]const [:0]const u8?`	`[]`	Keywords/tags - always Vec for consistency
`language`	`[:0]const u8?`	`null`	Primary language (ISO 639 code)
`createdAt`	`[:0]const u8?`	`null`	Creation timestamp (ISO 8601 format)
`modifiedAt`	`[:0]const u8?`	`null`	Last modification timestamp (ISO 8601 format)
`createdBy`	`[:0]const u8?`	`null`	User who created the document
`modifiedBy`	`[:0]const u8?`	`null`	User who last modified the document
`pages`	`PageStructure?`	`null`	Page/slide/sheet structure with boundaries
`format`	`FormatMetadata?`	`null`	Format-specific metadata (discriminated union) Contains detailed metadata specific to the document format. Serialized as a nested `"format"` object with a `format_type` discriminator field.
`imagePreprocessing`	`ImagePreprocessingMetadata?`	`null`	Image preprocessing metadata (when OCR preprocessing was applied)
`jsonSchema`	`[:0]const u8?`	`null`	JSON schema (for structured data extraction)
`error`	`ErrorMetadata?`	`null`	Error metadata (for batch operations)
`extractionDurationMs`	`u64?`	`null`	Extraction duration in milliseconds (for benchmarking). This field is populated by batch extraction to provide per-file timing information. It's `null` for single-file extraction (which uses external timing).
`category`	`[:0]const u8?`	`null`	Document category (from frontmatter or classification).
`tags`	`[]const [:0]const u8?`	`[]`	Document tags (from frontmatter).
`documentVersion`	`[:0]const u8?`	`null`	Document version string (from frontmatter).
`abstractText`	`[:0]const u8?`	`null`	Abstract or summary text (from frontmatter).
`outputFormat`	`[:0]const u8?`	`null`	Output format identifier (e.g., "markdown", "html", "text"). Set by the output format pipeline stage when format conversion is applied. Previously stored in `metadata.additional["output_format"]`.
`ocrUsed`	`bool`	—	Whether OCR was used during extraction. Set to `true` whenever the extraction pipeline ran an OCR backend (Tesseract, PaddleOCR, VLM, etc.) and used that output as the primary or fallback text. `false` means native text extraction was used exclusively.
`additional`	`std.StringHashMap([:0]const u8)`	`{}`	Additional custom fields from postprocessors. Serialized as a nested `"additional"` object (not flattened at root level). Uses `Cow<'static, str>` keys so static string keys avoid allocation.

Methods¶

isEmpty()¶

Returns true when no metadata fields, format-specific metadata, or additional postprocessor fields are populated.

Signature:

pub fn isEmpty(self: *const Metadata) bool

ModelPaths¶

Combined paths to all models needed for OCR (backward compatibility).

Field	Type	Default	Description
`detModel`	`[:0]const u8`	—	Path to the detection model directory.
`clsModel`	`[:0]const u8`	—	Path to the classification model directory.
`recModel`	`[:0]const u8`	—	Path to the recognition model directory.
`dictFile`	`[:0]const u8`	—	Path to the character dictionary file.

OcrBackend¶

Trait for OCR backend plugins.

Implement this trait to add custom OCR capabilities. OCR backends can be:

Native Rust implementations (like Tesseract)
FFI bridges to Python libraries (like EasyOCR, PaddleOCR)
Cloud-based OCR services (Google Vision, AWS Textract, etc.)

Thread Safety¶

OCR backends must be thread-safe (Send + Sync) to support concurrent processing.

Methods¶

processImage()¶

Process an image and extract text via OCR.

Returns:

An ExtractionResult containing the extracted text and metadata.

Errors:

KreuzbergError.Ocr - OCR processing failed
KreuzbergError.Validation - Invalid image format or configuration
KreuzbergError.Io - I/O errors (these always bubble up)

Reading `backend_options`¶

Backends that support runtime tuning can read config.backend_options and deserialize only the keys they care about. Unknown keys are silently ignored, so multiple backends can coexist in a pipeline without key conflicts.

Signature:

pub fn processImage(self: *const OcrBackend, image_bytes: []const u8, config: OcrConfig) Error!ExtractionResult

processImageFile()¶

Process a file and extract text via OCR.

Default implementation reads the file and calls process_image. Override for custom file handling or optimizations.

Errors:

Same as process_image, plus file I/O errors.

Signature:

pub fn processImageFile(self: *const OcrBackend, path: [:0]const u8, config: OcrConfig) Error!ExtractionResult

supportsLanguage()¶

Check if this backend supports a given language code.

Returns:

true if the language is supported, false otherwise.

Signature:

pub fn supportsLanguage(self: *const OcrBackend, lang: [:0]const u8) bool

backendType()¶

Get the backend type identifier.

Returns:

The backend type enum value.

Signature:

pub fn backendType(self: *const OcrBackend) OcrBackendType

supportedLanguages()¶

Optional: Get a list of all supported languages.

Defaults to empty list. Override to provide comprehensive language support info.

Signature:

pub fn supportedLanguages(self: *const OcrBackend) []const [:0]const u8

supportsTableDetection()¶

Optional: Check if the backend supports table detection.

Defaults to false. Override if your backend can detect and extract tables.

Signature:

pub fn supportsTableDetection(self: *const OcrBackend) bool

supportsDocumentProcessing()¶

Check if the backend supports direct document-level processing (e.g. for PDFs).

Defaults to false. Override if the backend has optimized document processing.

Signature:

pub fn supportsDocumentProcessing(self: *const OcrBackend) bool

processDocument()¶

Process a document file directly via OCR.

Only called if supports_document_processing returns true.

Signature:

pub fn processDocument(self: *const OcrBackend, path: [:0]const u8, config: OcrConfig) Error!ExtractionResult

OcrCacheStats¶

Field	Type	Default	Description
`totalFiles`	`u64`	—	Total files
`totalSizeMb`	`f64`	—	Total size mb

OcrConfidence¶

Confidence scores for an OCR element.

Separates detection confidence (how confident that text exists at this location) from recognition confidence (how confident about the actual text content).

Field	Type	Default	Description
`detection`	`f64?`	`null`	Detection confidence: how confident the OCR engine is that text exists here. PaddleOCR provides this as `box_score`, Tesseract doesn't have a direct equivalent. Range: 0.0 to 1.0 (or None if not available).
`recognition`	`f64`	—	Recognition confidence: how confident about the text content. Range: 0.0 to 1.0.

OcrConfig¶

OCR configuration.

Field	Type	Default	Description
`enabled`	`bool`	`true`	Whether OCR is enabled. Setting `enabled: false` is a shorthand for `disable_ocr: true` on the parent `ExtractionConfig`. Images return metadata only; PDFs use native text extraction without OCR fallback. Defaults to `true`. When `false`, all other OCR settings are ignored.
`backend`	`[:0]const u8`	—	OCR backend: tesseract, easyocr, paddleocr
`language`	`[:0]const u8`	—	Language code (e.g., "eng", "deu")
`tesseractConfig`	`TesseractConfig?`	`null`	Tesseract-specific configuration (optional)
`outputFormat`	`OutputFormat?`	`null`	Output format for OCR results (optional, for format conversion)
`paddleOcrConfig`	`[:0]const u8?`	`null`	PaddleOCR-specific configuration (optional, JSON passthrough)
`backendOptions`	`[:0]const u8?`	`null`	Arbitrary per-call options passed through to the backend unchanged. Custom OCR backends and built-in backends that support runtime tuning can read this value and deserialize the keys they care about. Keys unknown to the backend are silently ignored. This is the recommended extension point for per-call parameters that are not covered by the typed fields above (e.g. mode switching, preprocessing flags, inference batch size). Scope: when `pipeline` is `null`, this value is propagated to the primary stage of the auto-constructed pipeline. When `pipeline` is explicitly set, this field has no effect — the caller must set `OcrPipelineStage.backend_options` directly on the relevant stage(s) instead. Example: `json { "mode": "fast", "enable_layout": true, "timeout_ms": 5000 }`
`elementConfig`	`OcrElementConfig?`	`null`	OCR element extraction configuration
`qualityThresholds`	`OcrQualityThresholds?`	`null`	Quality thresholds for the native-text-to-OCR fallback decision. When None, uses compiled defaults (matching previous hardcoded behavior).
`pipeline`	`OcrPipelineConfig?`	`null`	Multi-backend OCR pipeline configuration. When set, enables weighted fallback across multiple OCR backends based on output quality. When None, uses the single `backend` field (same as today).
`autoRotate`	`bool`	`false`	Enable automatic page rotation based on orientation detection. When enabled, uses Tesseract's `DetectOrientationScript()` to detect page orientation (0/90/180/270 degrees) before OCR. If the page is rotated with high confidence, the image is corrected before recognition. This is critical for handling rotated scanned documents.
`vlmConfig`	`LlmConfig?`	`null`	VLM (Vision Language Model) OCR configuration. Required when `backend` is `"vlm"`. Uses liter-llm to send page images to a vision model for text extraction.
`vlmPrompt`	`[:0]const u8?`	`null`	Custom Jinja2 prompt template for VLM OCR. When `null`, uses the default template. Available variables: - `{{ language }}` — The document language code (e.g., "eng", "deu").
`acceleration`	`AccelerationConfig?`	`null`	Hardware acceleration for ONNX Runtime models (e.g. PaddleOCR, layout detection). Not user-configurable via config files — injected at runtime from `ExtractionConfig.acceleration` before each `process_image` call.
`tessdataBytes`	`std.StringHashMap([]const u8)?`	`null`	Caller-supplied Tesseract `traineddata` bytes per language code. Primary use case is the WASM build, which has no filesystem and cannot download tessdata at runtime. Native builds typically rely on `TessdataManager` and ignore this field. When present, the WASM Tesseract backend prefers these bytes over its compile-time-bundled English data. Skipped by serde to keep config files small — supply via the typed API at runtime.

Methods¶

default()¶

Signature:

pub fn default() OcrConfig

OcrElement¶

A unified OCR element representing detected text with full metadata.

This is the primary type for structured OCR output, preserving all information from both Tesseract and PaddleOCR backends.

Field	Type	Default	Description
`text`	`[:0]const u8`	—	The recognized text content.
`geometry`	`OcrBoundingGeometry`	`OcrBoundingGeometry.Rectangle`	Bounding geometry (rectangle or quadrilateral).
`confidence`	`OcrConfidence`	—	Confidence scores for detection and recognition.
`level`	`OcrElementLevel`	`OcrElementLevel.Line`	Hierarchical level (word, line, block, page).
`rotation`	`OcrRotation?`	`null`	Rotation information (if detected).
`pageNumber`	`u32`	—	Page number (1-indexed).
`parentId`	`[:0]const u8?`	`null`	Parent element ID for hierarchical relationships. Only used for Tesseract output which has word -> line -> block hierarchy.
`backendMetadata`	`std.StringHashMap([:0]const u8)`	`{}`	Backend-specific metadata that doesn't fit the unified schema.

OcrElementConfig¶

Configuration for OCR element extraction.

Controls how OCR elements are extracted and filtered.

Field	Type	Default	Description
`includeElements`	`bool`	—	Whether to include OCR elements in the extraction result. When true, the `ocr_elements` field in `ExtractionResult` will be populated.
`minLevel`	`OcrElementLevel`	`OcrElementLevel.Line`	Minimum hierarchical level to include. Elements below this level (e.g., words when min_level is Line) will be excluded.
`minConfidence`	`f64`	—	Minimum recognition confidence threshold (0.0-1.0). Elements with confidence below this threshold will be filtered out.
`buildHierarchy`	`bool`	—	Whether to build hierarchical relationships between elements. When true, `parent_id` fields will be populated based on spatial containment. Only meaningful for Tesseract output.

OcrExtractionResult¶

OCR extraction result.

Result of performing OCR on an image or scanned document, including recognized text and detected tables.

Field	Type	Default	Description
`content`	`[:0]const u8`	—	Recognized text content
`mimeType`	`[:0]const u8`	—	Original MIME type of the processed image
`metadata`	`std.StringHashMap([:0]const u8)`	—	OCR processing metadata (confidence scores, language, etc.)
`tables`	`[]const OcrTable`	—	Tables detected and extracted via OCR
`ocrElements`	`[]const OcrElement?`	`/* serde(default) */`	Structured OCR elements with bounding boxes and confidence scores. Available when TSV output is requested or table detection is enabled.
`internalDocument`	`[:0]const u8?`	`null`	Structured document produced from hOCR parsing. Carries paragraph structure, bounding boxes, and confidence scores that the flattened `content` string discards.

OcrMetadata¶

OCR processing metadata.

Captures information about OCR processing configuration and results.

Field	Type	Default	Description
`language`	`[:0]const u8`	—	OCR language code(s) used
`psm`	`i32`	—	Tesseract Page Segmentation Mode (PSM)
`outputFormat`	`[:0]const u8`	—	Output format (e.g., "text", "hocr")
`tableCount`	`u32`	—	Number of tables detected
`tableRows`	`u32?`	`null`	Table rows
`tableCols`	`u32?`	`null`	Table cols

OcrPipelineConfig¶

Multi-backend OCR pipeline with quality-based fallback.

Backends are tried in priority order (highest first). After each backend produces output, quality is evaluated. If it meets quality_thresholds.pipeline_min_quality, the result is accepted. Otherwise the next backend is tried.

Field	Type	Default	Description
`stages`	`[]const OcrPipelineStage`	—	Ordered list of backends to try. Sorted by priority (descending) at runtime.
`qualityThresholds`	`OcrQualityThresholds`	`/* serde(default) */`	Quality thresholds for deciding whether to accept a result or try the next backend.

OcrPipelineStage¶

A single backend stage in the OCR pipeline.

Field	Type	Default	Description
`backend`	`[:0]const u8`	—	Backend name: "tesseract", "paddleocr", "easyocr", or a custom registered name.
`priority`	`u32`	`/* serde(default) */`	Priority weight (higher = tried first). Stages are sorted by priority descending.
`language`	`[:0]const u8?`	`/* serde(default) */`	Language override for this stage (None = use parent OcrConfig.language).
`tesseractConfig`	`TesseractConfig?`	`/* serde(default) */`	Tesseract-specific config override for this stage.
`paddleOcrConfig`	`[:0]const u8?`	`/* serde(default) */`	PaddleOCR-specific config for this stage.
`vlmConfig`	`LlmConfig?`	`/* serde(default) */`	VLM config override for this pipeline stage.
`backendOptions`	`[:0]const u8?`	`/* serde(default) */`	Arbitrary per-call options passed through to the backend unchanged. Backends that support runtime tuning (mode switching, preprocessing flags, inference parameters, etc.) read this value and deserialize the keys they care about. Keys unknown to the backend are silently ignored, so options from different backends can coexist in the same config without conflict. Example (custom backend): `json { "mode": "fast", "enable_layout": true }`

OcrQualityThresholds¶

Quality thresholds for OCR fallback decisions and pipeline quality gating.

All fields default to the values that match the previous hardcoded behavior, so OcrQualityThresholds.default() preserves existing semantics exactly.

Field	Type	Default	Description
`minTotalNonWhitespace`	`u64`	`64`	Minimum total non-whitespace characters to consider text substantive.
`minNonWhitespacePerPage`	`f64`	`32`	Minimum non-whitespace characters per page on average.
`minMeaningfulWordLen`	`u64`	`4`	Minimum character count for a word to be "meaningful".
`minMeaningfulWords`	`u64`	`3`	Minimum count of meaningful words before text is accepted.
`minAlnumRatio`	`f64`	`0.3`	Minimum alphanumeric ratio (non-whitespace chars that are alphanumeric).
`minGarbageChars`	`u64`	`5`	Minimum Unicode replacement characters (U+FFFD) to trigger OCR fallback.
`maxFragmentedWordRatio`	`f64`	`0.6`	Maximum fraction of short (1-2 char) words before text is considered fragmented.
`criticalFragmentedWordRatio`	`f64`	`0.8`	Critical fragmentation threshold — triggers OCR regardless of meaningful words. Normal English text has ~20-30% short words. 80%+ is definitive garbage.
`minAvgWordLength`	`f64`	`2`	Minimum average word length. Below this with enough words indicates garbled extraction.
`minWordsForAvgLengthCheck`	`u64`	`50`	Minimum word count before average word length check applies.
`minConsecutiveRepeatRatio`	`f64`	`0.08`	Minimum consecutive word repetition ratio to detect column scrambling.
`minWordsForRepeatCheck`	`u64`	`50`	Minimum word count before consecutive repetition check is applied.
`substantiveMinChars`	`u64`	`100`	Minimum character count for "substantive markdown" OCR skip gate.
`nonTextMinChars`	`u64`	`20`	Minimum character count for "non-text content" OCR skip gate.
`alnumWsRatioThreshold`	`f64`	`0.4`	Alphanumeric+whitespace ratio threshold for skip decisions.
`pipelineMinQuality`	`f64`	`0.5`	Minimum quality score (0.0-1.0) for a pipeline stage result to be accepted. If the result from a backend scores below this, try the next backend.

Methods¶

default()¶

Signature:

pub fn default() OcrQualityThresholds

OcrRotation¶

Rotation information for an OCR element.

Field	Type	Default	Description
`angleDegrees`	`f64`	—	Rotation angle in degrees (0, 90, 180, 270 for PaddleOCR).
`confidence`	`f64?`	`null`	Confidence score for the rotation detection.

OcrTable¶

Table detected via OCR.

Represents a table structure recognized during OCR processing.

Field	Type	Default	Description
`cells`	`[]const []const [:0]const u8`	—	Table cells as a 2D vector (rows × columns)
`markdown`	`[:0]const u8`	—	Markdown representation of the table
`pageNumber`	`u32`	—	Page number where the table was found (1-indexed)
`boundingBox`	`OcrTableBoundingBox?`	`/* serde(default) */`	Bounding box of the table in pixel coordinates (from OCR word positions).

OcrTableBoundingBox¶

Bounding box for an OCR-detected table in pixel coordinates.

Field	Type	Default	Description
`left`	`u32`	—	Left x-coordinate (pixels)
`top`	`u32`	—	Top y-coordinate (pixels)
`right`	`u32`	—	Right x-coordinate (pixels)
`bottom`	`u32`	—	Bottom y-coordinate (pixels)

OrientationResult¶

Document orientation detection result.

Field	Type	Default	Description
`degrees`	`u32`	—	Detected orientation in degrees (0, 90, 180, or 270).
`confidence`	`f32`	—	Confidence score (0.0-1.0).

PaddleOcrConfig¶

Configuration for PaddleOCR backend.

Configures PaddleOCR text detection and recognition with multi-language support. Uses a builder pattern for convenient configuration.

Field	Type	Default	Description
`language`	`[:0]const u8`	—	Language code (e.g., "en", "ch", "jpn", "kor", "deu", "fra")
`cacheDir`	`[:0]const u8?`	`null`	Optional custom cache directory for model files
`useAngleCls`	`bool`	—	Enable angle classification for rotated text (default: false). Can misfire on short text regions, rotating crops incorrectly before recognition.
`enableTableDetection`	`bool`	—	Enable table structure detection (default: false)
`detDbThresh`	`f32`	—	Database threshold for text detection (default: 0.3) Range: 0.0-1.0, higher values require more confident detections
`detDbBoxThresh`	`f32`	—	Box threshold for text bounding box refinement (default: 0.5) Range: 0.0-1.0
`detDbUnclipRatio`	`f32`	—	Unclip ratio for expanding text bounding boxes (default: 1.6) Controls the expansion of detected text regions
`detLimitSideLen`	`u32`	—	Maximum side length for detection image (default: 960) Larger images may be resized to this limit for faster inference
`recBatchNum`	`u32`	—	Batch size for recognition inference (default: 6) Number of text regions to process simultaneously
`padding`	`u32`	—	Padding in pixels added around the image before detection (default: 10). Large values can include surrounding content like table gridlines.
`dropScore`	`f32`	—	Minimum recognition confidence score for text lines (default: 0.5). Text regions with recognition confidence below this threshold are discarded. Matches PaddleOCR Python's `drop_score` parameter. Range: 0.0-1.0
`modelTier`	`[:0]const u8`	—	Model tier controlling detection/recognition model size and accuracy trade-off. - `"mobile"` (default): Lightweight models (~4.5MB detection, ~16.5MB recognition), fast download and inference - `"server"`: Large, high-accuracy models (~88MB detection, ~84MB recognition), best for GPU or complex documents

Methods¶

withCacheDir()¶

Sets a custom cache directory for model files.

Signature:

pub fn withCacheDir(self: *const PaddleOcrConfig, path: [:0]const u8) PaddleOcrConfig

withTableDetection()¶

Enables or disables table structure detection.

Signature:

pub fn withTableDetection(self: *const PaddleOcrConfig, enable: bool) PaddleOcrConfig

withAngleCls()¶

Enables or disables angle classification for rotated text.

Signature:

pub fn withAngleCls(self: *const PaddleOcrConfig, enable: bool) PaddleOcrConfig

withDetDbThresh()¶

Sets the database threshold for text detection.

Signature:

pub fn withDetDbThresh(self: *const PaddleOcrConfig, threshold: f32) PaddleOcrConfig

withDetDbBoxThresh()¶

Sets the box threshold for text bounding box refinement.

Signature:

pub fn withDetDbBoxThresh(self: *const PaddleOcrConfig, threshold: f32) PaddleOcrConfig

withDetDbUnclipRatio()¶

Sets the unclip ratio for expanding text bounding boxes.

Signature:

pub fn withDetDbUnclipRatio(self: *const PaddleOcrConfig, ratio: f32) PaddleOcrConfig

withDetLimitSideLen()¶

Sets the maximum side length for detection images.

Signature:

pub fn withDetLimitSideLen(self: *const PaddleOcrConfig, length: u32) PaddleOcrConfig

withRecBatchNum()¶

Sets the batch size for recognition inference.

Signature:

pub fn withRecBatchNum(self: *const PaddleOcrConfig, batch_size: u32) PaddleOcrConfig

withDropScore()¶

Sets the minimum recognition confidence threshold.

Signature:

pub fn withDropScore(self: *const PaddleOcrConfig, score: f32) PaddleOcrConfig

withPadding()¶

Sets padding in pixels added around images before detection.

Signature:

pub fn withPadding(self: *const PaddleOcrConfig, padding: u32) PaddleOcrConfig

withModelTier()¶

Sets the model tier controlling detection/recognition model size.

Signature:

pub fn withModelTier(self: *const PaddleOcrConfig, tier: [:0]const u8) PaddleOcrConfig

default()¶

Creates a default configuration with English language support.

Signature:

pub fn default() PaddleOcrConfig

PageBoundary¶

Byte offset boundary for a page.

Tracks where a specific page's content starts and ends in the main content string, enabling mapping from byte positions to page numbers. Offsets are guaranteed to be at valid UTF-8 character boundaries when using standard String methods (push_str, push, etc.).

Field	Type	Default	Description
`byteStart`	`u64`	—	Byte offset where this page starts in the content string (UTF-8 valid boundary, inclusive)
`byteEnd`	`u64`	—	Byte offset where this page ends in the content string (UTF-8 valid boundary, exclusive)
`pageNumber`	`u32`	—	Page number (1-indexed)

PageConfig¶

Page extraction and tracking configuration.

Controls how pages are extracted, tracked, and represented in the extraction results. When null, page tracking is disabled.

Page range tracking in chunk metadata (first_page/last_page) is automatically enabled when page boundaries are available and chunking is configured.

Field	Type	Default	Description
`extractPages`	`bool`	`false`	Extract pages as separate array (ExtractionResult.pages)
`insertPageMarkers`	`bool`	`false`	Insert page markers in main content string
`markerFormat`	`[:0]const u8`	`"

"` | Page marker format (use {page_num} placeholder) Default: "\n\n\n\n" |

Methods¶

default()¶

Signature:

pub fn default() PageConfig

PageContent¶

Content for a single page/slide.

When page extraction is enabled, documents are split into per-page content with associated tables and images mapped to each page.

Performance¶

Uses Arc-wrapped tables and images for memory efficiency:

Vec<Arc<Table>> enables zero-copy sharing of table data
Vec<Arc<ExtractedImage>> enables zero-copy sharing of image data
Maintains exact JSON compatibility via custom Serialize/Deserialize

This reduces memory overhead for documents with shared tables/images by avoiding redundant copies during serialization.

Field Type Default Description

pageNumber u32 — Page number (1-indexed)

content [:0]const u8 — Text content for this page

tables

[]const Table

/* serde(default) */

Tables found on this page (uses Arc for memory efficiency) Serializes as Vec for JSON compatibility while maintaining Arc semantics in-memory for zero-copy sharing.

`imageIndices`	`[]const u32`	`/* serde(default) */`	Indices into `ExtractionResult.images` for images found on this page. Each value is a zero-based index into the top-level `images` collection. Only populated when `extract_images = true` in the extraction config.
`hierarchy`	`PageHierarchy?`	`null`	Hierarchy information for the page (when hierarchy extraction is enabled) Contains text hierarchy levels (H1-H6) extracted from the page content.
`isBlank`	`bool?`	`null`	Whether this page is blank (no meaningful text content) Determined during extraction based on text content analysis. A page is blank if it has fewer than 3 non-whitespace characters and contains no tables or images.
`layoutRegions`	`[]const LayoutRegion?`	`null`	Layout detection regions for this page (when layout detection is enabled). Contains detected layout regions with class, confidence, bounding box, and area fraction. Only populated when layout detection is configured.

PageHierarchy¶

Page hierarchy structure containing heading levels and block information.

Used when PDF text hierarchy extraction is enabled. Contains hierarchical blocks with heading levels (H1-H6) for semantic document structure.

Field	Type	Default	Description
`blockCount`	`u32`	—	Number of hierarchy blocks on this page
`blocks`	`[]const HierarchicalBlock`	`/* serde(default) */`	Hierarchical blocks with heading levels

PageInfo¶

Metadata for individual page/slide/sheet.

Captures per-page information including dimensions, content counts, and visibility state (for presentations).

Field	Type	Default	Description
`number`	`u32`	—	Page number (1-indexed)
`title`	`[:0]const u8?`	`null`	Page title (usually for presentations)
`dimensions`	`[]const f64?`	`null`	Dimensions in points (PDF) or pixels (images): (width, height)
`imageCount`	`u32?`	`null`	Number of images on this page
`tableCount`	`u32?`	`null`	Number of tables on this page
`hidden`	`bool?`	`null`	Whether this page is hidden (e.g., in presentations)
`isBlank`	`bool?`	`null`	Whether this page is blank (no meaningful text, no images, no tables) A page is considered blank if it has fewer than 3 non-whitespace characters and contains no tables or images. This is useful for filtering out empty pages in scanned documents or PDFs with blank separator pages.
`hasVectorGraphics`	`bool`	`/* serde(default) */`	Whether this page contains non-trivial vector graphics (paths, shapes, curves) Indicates the presence of vector-drawn content such as charts, diagrams, or geometric shapes (e.g., from Adobe InDesign, LaTeX TikZ). These are invisible to `ExtractionResult.images` since they are not embedded as raster XObjects. Set to `true` when path count exceeds a heuristic threshold, signaling that downstream consumers may want to rasterize the page to capture this content. Only populated for PDFs; `null` for other document types.

PageStructure¶

Unified page structure for documents.

Supports different page types (PDF pages, PPTX slides, Excel sheets) with character offset boundaries for chunk-to-page mapping.

Field	Type	Default	Description
`totalCount`	`u32`	—	Total number of pages/slides/sheets
`unitType`	`PageUnitType`	—	Type of paginated unit
`boundaries`	`[]const PageBoundary?`	`null`	Character offset boundaries for each page Maps character ranges in the extracted content to page numbers. Used for chunk page range calculation.
`pages`	`[]const PageInfo?`	`null`	Detailed per-page metadata (optional, only when needed)

PdfAnnotation¶

A PDF annotation extracted from a document page.

Field	Type	Default	Description
`annotationType`	`PdfAnnotationType`	—	The type of annotation.
`content`	`[:0]const u8?`	`null`	Text content of the annotation (e.g., comment text, link URL).
`pageNumber`	`u32`	—	Page number where the annotation appears (1-indexed).
`boundingBox`	`BoundingBox?`	`null`	Bounding box of the annotation on the page.

PdfConfig¶

PDF-specific configuration.

Field	Type	Default	Description
`extractImages`	`bool`	`false`	Extract images from PDF
`extractTables`	`bool`	`true`	Extract tables from PDF. When `true` (default), runs pdf_oxide's native grid detector and, if it finds nothing, falls back to the heuristic text-layer reconstruction in `pdf.oxide.table.extract_tables_heuristic`. Set to `false` to skip both passes — `tables` will then be empty in the result.
`passwords`	`[]const [:0]const u8?`	`null`	List of passwords to try when opening encrypted PDFs
`extractMetadata`	`bool`	`true`	Extract PDF metadata
`hierarchy`	`HierarchyConfig?`	`null`	Hierarchy extraction configuration (None = hierarchy extraction disabled)
`extractAnnotations`	`bool`	`false`	Extract PDF annotations (text notes, highlights, links, stamps). Default: false
`topMarginFraction`	`f32?`	`null`	Top margin fraction (0.0–1.0) of page height to exclude headers/running heads. Default: 0.06 (6%)
`bottomMarginFraction`	`f32?`	`null`	Bottom margin fraction (0.0–1.0) of page height to exclude footers/page numbers. Default: 0.05 (5%)
`allowSingleColumnTables`	`bool`	`false`	Allow single-column pseudo tables in extraction results. By default, tables with fewer than 2 columns (layout-guided) or 3 columns (heuristic) are rejected. When `true`, the minimum column count is relaxed to 1, allowing single-column structured data (glossaries, itemized lists) to be emitted as tables. Other quality filters (density, sparsity, prose detection) still apply.
`ocrInlineImages`	`bool`	`false`	Perform OCR on inline images extracted from PDF pages and attach the recognized text to each `ExtractedImage.ocr_result`. Requires Tesseract to be available; if `ExtractionConfig.ocr` is `null` the extractor falls back to `TesseractConfig.default()`. Per-image failures degrade gracefully (the image is returned without OCR text rather than failing the whole extraction). Default: `false`.

Methods¶

default()¶

Signature:

pub fn default() PdfConfig

PdfMetadata¶

PDF-specific metadata.

Contains metadata fields specific to PDF documents that are not in the common Metadata structure. Common fields like title, authors, keywords, and dates are at the Metadata level.

Field	Type	Default	Description
`pdfVersion`	`[:0]const u8?`	`null`	PDF version (e.g., "1.7", "2.0")
`producer`	`[:0]const u8?`	`null`	PDF producer (application that created the PDF)
`isEncrypted`	`bool?`	`null`	Whether the PDF is encrypted/password-protected
`width`	`i64?`	`null`	First page width in points (1/72 inch)
`height`	`i64?`	`null`	First page height in points (1/72 inch)
`pageCount`	`u32?`	`null`	Total number of pages in the PDF document

Plugin¶

Base trait that all plugins must implement.

This trait provides common functionality for plugin lifecycle management, identification, and metadata.

Thread Safety¶

All plugins must be Send + Sync to support concurrent usage across threads.

Methods¶

name()¶

Returns the unique name/identifier for this plugin.

The name should be:

Unique across all plugins
Lowercase with hyphens (e.g., "my-custom-plugin")
URL-safe characters only

Signature:

pub fn name(self: *const Plugin) [:0]const u8

version()¶

Returns the semantic version of this plugin.

Should follow semver format: MAJOR.MINOR.PATCH

Defaults to the kreuzberg crate version.

Signature:

pub fn version(self: *const Plugin) [:0]const u8

initialize()¶

Initialize the plugin.

Called once when the plugin is registered. Use this to:

Load configuration
Initialize resources (connections, caches, etc.)
Validate dependencies

Thread Safety¶

This method takes &self instead of &mut self to work with Arc<dyn Plugin>. Plugins needing mutable state during initialization should use interior mutability patterns (Mutex, RwLock, OnceCell, etc.).

Errors:

Should return an error if initialization fails. The plugin will not be registered if this method returns an error.

Defaults to a no-op for stateless plugins.

Signature:

pub fn initialize(self: *const Plugin) Error!void

shutdown()¶

Shutdown the plugin.

Called when the plugin is being unregistered or the application is shutting down. Use this to:

Close connections
Flush caches
Release resources

Thread Safety¶

This method takes &self instead of &mut self to work with Arc<dyn Plugin>. Plugins needing mutable state during shutdown should use interior mutability patterns (Mutex, RwLock, etc.).

Errors:

Errors during shutdown are logged but don't prevent the shutdown process.

Defaults to a no-op for stateless plugins.

Signature:

pub fn shutdown(self: *const Plugin) Error!void

description()¶

Optional plugin description for debugging and logging.

Defaults to empty string if not overridden.

Signature:

pub fn description(self: *const Plugin) [:0]const u8

author()¶

Optional plugin author information.

Defaults to empty string if not overridden.

Signature:

pub fn author(self: *const Plugin) [:0]const u8

PostProcessor¶

Trait for post-processor plugins.

Post-processors transform or enrich extraction results after the initial extraction is complete. They can:

Clean and normalize text
Add metadata (language, keywords, entities)
Split content into chunks
Score quality
Apply custom transformations

Processing Order¶

Post-processors are executed in stage order:

Early - Language detection, entity extraction
Middle - Keyword extraction, token reduction
Late - Custom hooks, final validation

Within each stage, processors are executed in registration order.

Error Handling¶

Post-processor errors are non-fatal by default - they're captured in metadata and execution continues. To make errors fatal, return an error from process().

Thread Safety¶

Post-processors must be thread-safe (Send + Sync).

Methods¶

process()¶

Process an extraction result.

Transform or enrich the extraction result. Can modify:

content - The extracted text
metadata - Add or update metadata fields
tables - Modify or enhance table data

Returns:

Ok(()) if processing succeeded, Err(...) for fatal failures.

Errors:

Return errors for fatal processing failures. Non-fatal errors should be captured in metadata directly on the result.

Performance¶

This signature avoids unnecessary cloning of large extraction results by taking a mutable reference instead of ownership. Processors modify the result in place.

Example - Language Detection¶

Example - Text Cleaning¶

async fn process(&self, result: &mut ExtractionResult, config: &ExtractionConfig)
    -> Result<()> {
    // Remove excessive whitespace
    result.content = result
        .content
        .split_whitespace()
        .collect::<Vec<_>>()
        .join(" ");

    Ok(())
}

Signature:

pub fn process(self: *const PostProcessor, result: ExtractionResult, config: ExtractionConfig) Error!void

processingStage()¶

Get the processing stage for this post-processor.

Determines when this processor runs in the pipeline.

Returns:

The ProcessingStage (Early, Middle, or Late).

Signature:

pub fn processingStage(self: *const PostProcessor) ProcessingStage

shouldProcess()¶

Optional: Check if this processor should run for a given result.

Allows conditional processing based on MIME type, metadata, or content. Defaults to true (always run).

Returns:

true if the processor should run, false to skip.

Signature:

pub fn shouldProcess(self: *const PostProcessor, result: ExtractionResult, config: ExtractionConfig) bool

estimatedDurationMs()¶

Optional: Estimate processing time in milliseconds.

Used for logging and debugging. Defaults to 0 (unknown).

Returns:

Estimated processing time in milliseconds.

Signature:

pub fn estimatedDurationMs(self: *const PostProcessor, result: ExtractionResult) u64

priority()¶

Execution priority within the processing stage.

Higher values run first within the same ProcessingStage. Defaults to 50. Use 0-49 for fallback processors, 50 for normal processors, and 51-255 for high-priority processors that should run early in their stage.

Signature:

pub fn priority(self: *const PostProcessor) i32

PostProcessorConfig¶

Post-processor configuration.

Field	Type	Default	Description
`enabled`	`bool`	`true`	Enable post-processors
`enabledProcessors`	`[]const [:0]const u8?`	`null`	Whitelist of processor names to run (None = all enabled)
`disabledProcessors`	`[]const [:0]const u8?`	`null`	Blacklist of processor names to skip (None = none disabled)
`enabledSet`	`[]const [:0]const u8?`	`null`	Pre-computed AHashSet for O(1) enabled processor lookup
`disabledSet`	`[]const [:0]const u8?`	`null`	Pre-computed AHashSet for O(1) disabled processor lookup

Methods¶

default()¶

Signature:

pub fn default() PostProcessorConfig

PptxAppProperties¶

Application properties from docProps/app.xml for PPTX

Contains PowerPoint-specific document metadata.

Field	Type	Default	Description
`application`	`[:0]const u8?`	`null`	Application name (e.g., "Microsoft Office PowerPoint")
`appVersion`	`[:0]const u8?`	`null`	Application version
`totalTime`	`i32?`	`null`	Total editing time in minutes
`company`	`[:0]const u8?`	`null`	Company name
`docSecurity`	`i32?`	`null`	Document security level
`scaleCrop`	`bool?`	`null`	Scale crop flag
`linksUpToDate`	`bool?`	`null`	Links up to date flag
`sharedDoc`	`bool?`	`null`	Shared document flag
`hyperlinksChanged`	`bool?`	`null`	Hyperlinks changed flag
`slides`	`i32?`	`null`	Number of slides
`notes`	`i32?`	`null`	Number of notes
`hiddenSlides`	`i32?`	`null`	Number of hidden slides
`multimediaClips`	`i32?`	`null`	Number of multimedia clips
`presentationFormat`	`[:0]const u8?`	`null`	Presentation format (e.g., "Widescreen", "Standard")
`slideTitles`	`[]const [:0]const u8`	`[]`	Slide titles

PptxExtractionResult¶

PowerPoint (PPTX) extraction result.

Contains extracted slide content, metadata, and embedded images/tables.

Field	Type	Default	Description
`content`	`[:0]const u8`	—	Extracted text content from all slides
`metadata`	`PptxMetadata`	—	Presentation metadata
`slideCount`	`u64`	—	Total number of slides
`imageCount`	`u64`	—	Total number of embedded images
`tableCount`	`u64`	—	Total number of tables
`images`	`[]const ExtractedImage`	—	Extracted images from the presentation
`pageStructure`	`PageStructure?`	`null`	Slide structure with boundaries (when page tracking is enabled)
`pageContents`	`[]const PageContent?`	`null`	Per-slide content (when page tracking is enabled)
`document`	`DocumentStructure?`	`null`	Structured document representation
`hyperlinks`	`[]const [:0]const u8`	`/* serde(default) */`	Hyperlinks discovered in slides as (url, optional_label) pairs.
`officeMetadata`	`std.StringHashMap([:0]const u8)`	`/* serde(default) */`	Office metadata extracted from docProps/core.xml and docProps/app.xml. Contains keys like "title", "author", "created_by", "subject", "keywords", "modified_by", "created_at", "modified_at", etc.

PptxMetadata¶

PowerPoint presentation metadata.

Extracted from PPTX files containing slide counts and presentation details.

Field	Type	Default	Description
`slideCount`	`u32`	—	Total number of slides in the presentation
`slideNames`	`[]const [:0]const u8`	`[]`	Names of slides (if available)
`imageCount`	`u32?`	`null`	Number of embedded images
`tableCount`	`u32?`	`null`	Number of tables

ProcessingWarning¶

A non-fatal warning from a processing pipeline stage.

Captures errors from optional features that don't prevent extraction but may indicate degraded results.

Field	Type	Default	Description
`source`	`[:0]const u8`	—	The pipeline stage or feature that produced this warning (e.g., "embedding", "chunking", "language_detection", "output_format").
`message`	`[:0]const u8`	—	Human-readable description of what went wrong.

PstMetadata¶

Outlook PST archive metadata.

Field	Type	Default	Description
`messageCount`	`u64`	—	Number of messages

RakeParams¶

RAKE-specific parameters.

Field	Type	Default	Description
`minWordLength`	`u64`	`1`	Minimum word length to consider (default: 1).
`maxWordsPerPhrase`	`u64`	`3`	Maximum words in a keyword phrase (default: 3).

Methods¶

default()¶

Signature:

pub fn default() RakeParams

RecognizedTable¶

Pre-computed table markdown for a table detection region.

Produced by the TATR-based table structure recognizer and surfaced as part of layout-aware OCR results. The struct lives here (under layout-types, pure-Rust) so that consumers who do not enable layout-detection (ORT) can still reference the type in their own code.

Field	Type	Default	Description
`detectionBbox`	`BBox`	—	Detection bbox that this table corresponds to (for matching).
`cells`	`[]const []const [:0]const u8`	—	Table cells as a 2D vector (rows × columns).
`markdown`	`[:0]const u8`	—	Rendered markdown table.

Renderer¶

Trait for document renderers that convert InternalDocument to output strings.

Renderers are typically stateless converters that transform the internal document representation into a specific output format (Markdown, HTML, Djot, plain text, etc.). They participate in the standard Plugin lifecycle so custom renderers can be registered from any supported binding language.

The format name is exposed via Plugin.name. For stateless renderers the Plugin lifecycle methods (version, initialize, shutdown) all take no-op defaults and need not be overridden.

Thread Safety¶

Renderers must be Send + Sync (inherited from Plugin).

Methods¶

render()¶

Render an InternalDocument to the output format.

Returns:

The rendered output as a string.

Errors:

Returns an error if rendering fails.

Signature:

pub fn render(self: *const Renderer, doc: InternalDocument) Error![:0]const u8

SecurityLimits¶

Configuration for security limits across extractors.

All limits are intentionally conservative to prevent DoS attacks while still supporting legitimate documents.

Field	Type	Default	Description
`maxArchiveSize`	`u64`	`524288000`	Maximum uncompressed size for archives (500 MB)
`maxCompressionRatio`	`u64`	`100`	Maximum compression ratio before flagging as potential bomb (100:1)
`maxFilesInArchive`	`u64`	`10000`	Maximum number of files in archive (10,000)
`maxNestingDepth`	`u64`	`1024`	Maximum nesting depth for structures (100)
`maxEntityLength`	`u64`	`1048576`	Maximum length of any single XML entity / attribute / token (1 MiB). This is a per-token cap, NOT a total cap — billion-laughs class attacks where a single entity expands to hundreds of MB are caught here, while normal long text content (a paragraph, a CDATA block) is caught by `max_content_size` instead.
`maxContentSize`	`u64`	`104857600`	Maximum string growth per document (100 MB)
`maxIterations`	`u64`	`10000000`	Maximum iterations per operation
`maxXmlDepth`	`u64`	`1024`	Maximum XML depth (100 levels)
`maxTableCells`	`u64`	`100000`	Maximum cells per table (100,000)

Methods¶

default()¶

Signature:

pub fn default() SecurityLimits

ServerConfig¶

API server configuration.

This struct holds all configuration options for the Kreuzberg API server, including host/port settings, CORS configuration, and upload limits.

Defaults¶

host: "127.0.0.1" (localhost only)
port: 8000
cors_origins: empty vector (allows all origins)
max_request_body_bytes: 104_857_600 (100 MB)
max_multipart_field_bytes: 104_857_600 (100 MB)

Field	Type	Default	Description
`host`	`[:0]const u8`	—	Server host address (e.g., "127.0.0.1", "0.0.0.0")
`port`	`u16`	—	Server port number
`corsOrigins`	`[]const [:0]const u8`	`[]`	CORS allowed origins. Empty vector means allow all origins. If this is an empty vector, the server will accept requests from any origin. If populated with specific origins (e.g., `"<https://example.com"`>), only those origins will be allowed.
`maxRequestBodyBytes`	`u64`	—	Maximum size of request body in bytes (default: 100 MB)
`maxMultipartFieldBytes`	`u64`	—	Maximum size of multipart fields in bytes (default: 100 MB)

Methods¶

default()¶

Signature:

pub fn default() ServerConfig

listenAddr()¶

Get the server listen address (host:port).

Signature:

pub fn listenAddr(self: *const ServerConfig) [:0]const u8

corsAllowsAll()¶

Check if CORS allows all origins.

Returns true if the cors_origins vector is empty, meaning all origins are allowed. Returns false if specific origins are configured.

Signature:

pub fn corsAllowsAll(self: *const ServerConfig) bool

isOriginAllowed()¶

Check if a given origin is allowed by CORS configuration.

Returns true if:

CORS allows all origins (empty origins list), or
The given origin is in the allowed origins list

Signature:

pub fn isOriginAllowed(self: *const ServerConfig, origin: [:0]const u8) bool

maxRequestBodyMb()¶

Get maximum request body size in megabytes (rounded up).

Signature:

pub fn maxRequestBodyMb(self: *const ServerConfig) u64

maxMultipartFieldMb()¶

Get maximum multipart field size in megabytes (rounded up).

Signature:

pub fn maxMultipartFieldMb(self: *const ServerConfig) u64

StructuredData¶

Structured data (Schema.org, microdata, RDFa) block.

Field	Type	Default	Description
`dataType`	`StructuredDataType`	—	Type of structured data
`rawJson`	`[:0]const u8`	—	Raw JSON string representation
`schemaType`	`[:0]const u8?`	`null`	Schema type if detectable (e.g., "Article", "Event", "Product")

StructuredDataResult¶

Field	Type	Default	Description
`content`	`[:0]const u8`	—	The extracted text content
`format`	`[:0]const u8`	—	Format
`metadata`	`std.StringHashMap([:0]const u8)`	—	Document metadata
`textFields`	`[]const [:0]const u8`	—	Text fields

StructuredExtractionConfig¶

Configuration for LLM-based structured data extraction.

Sends extracted document content to a VLM with a JSON schema, returning structured data that conforms to the schema.

Field	Type	Default	Description
`schema`	`[:0]const u8`	—	JSON Schema defining the desired output structure.
`schemaName`	`[:0]const u8`	`/* serde(default) */`	Schema name passed to the LLM's structured output mode.
`schemaDescription`	`[:0]const u8?`	`/* serde(default) */`	Optional schema description for the LLM.
`strict`	`bool`	`/* serde(default) */`	Enable strict mode — output must exactly match the schema.
`prompt`	`[:0]const u8?`	`/* serde(default) */`	Custom Jinja2 extraction prompt template. When `null`, a default template is used. Available template variables: - `{{ content }}` — The extracted document text. - `{{ schema }}` — The JSON schema as a formatted string. - `{{ schema_name }}` — The schema name. - `{{ schema_description }}` — The schema description (may be empty).
`llm`	`LlmConfig`	—	LLM configuration for the extraction.

SupportedFormat¶

A supported document format entry.

Represents a file extension and its corresponding MIME type that Kreuzberg can process.

Field	Type	Default	Description
`extension`	`[:0]const u8`	—	File extension (without leading dot), e.g., "pdf", "docx"
`mimeType`	`[:0]const u8`	—	MIME type string, e.g., "application/pdf"

Table¶

Extracted table structure.

Represents a table detected and extracted from a document (PDF, image, etc.). Tables are converted to both structured cell data and Markdown format.

Field	Type	Default	Description
`cells`	`[]const []const [:0]const u8`	`[]`	Table cells as a 2D vector (rows × columns)
`markdown`	`[:0]const u8`	—	Markdown representation of the table
`pageNumber`	`u32`	—	Page number where the table was found (1-indexed)
`boundingBox`	`BoundingBox?`	`null`	Bounding box of the table on the page (PDF coordinates: x0=left, y0=bottom, x1=right, y1=top). Only populated for PDF-extracted tables when position data is available.

TableCell¶

Individual table cell with content and optional styling.

Future extension point for rich table support with cell-level metadata.

Field	Type	Default	Description
`content`	`[:0]const u8`	—	Cell content as text
`rowSpan`	`u32`	—	Row span (number of rows this cell spans)
`colSpan`	`u32`	—	Column span (number of columns this cell spans)
`isHeader`	`bool`	—	Whether this is a header cell

TableGrid¶

Structured table grid with cell-level metadata.

Stores row/column dimensions and a flat list of cells with position info.

Field	Type	Default	Description
`rows`	`u32`	—	Number of rows in the table.
`cols`	`u32`	—	Number of columns in the table.
`cells`	`[]const GridCell`	`[]`	All cells in row-major order.

TesseractConfig¶

Tesseract OCR configuration.

Provides fine-grained control over Tesseract OCR engine parameters. Most users can use the defaults, but these settings allow optimization for specific document types (invoices, handwriting, etc.).

Field	Type	Default	Description
`language`	`[:0]const u8`	`"eng"`	Language code (e.g., "eng", "deu", "fra")
`psm`	`i32`	`3`	Page Segmentation Mode (0-13). Common values: - 3: Fully automatic page segmentation (native default) - 6: Assume a single uniform block of text (WASM default — avoids layout-analysis hang) - 11: Sparse text with no particular order
`outputFormat`	`[:0]const u8`	`"markdown"`	Output format ("text" or "markdown")
`oem`	`i32`	`3`	OCR Engine Mode (0-3). - 0: Legacy engine only - 1: Neural nets (LSTM) only (usually best) - 2: Legacy + LSTM - 3: Default (based on what's available)
`minConfidence`	`f64`	`0`	Minimum confidence threshold (0.0-100.0). Words with confidence below this threshold may be rejected or flagged.
`preprocessing`	`ImagePreprocessingConfig?`	`null`	Image preprocessing configuration. Controls how images are preprocessed before OCR. Can significantly improve quality for scanned documents or low-quality images.
`enableTableDetection`	`bool`	`true`	Enable automatic table detection and reconstruction
`tableMinConfidence`	`f64`	`0`	Minimum confidence threshold for table detection (0.0-1.0)
`tableColumnThreshold`	`i32`	`50`	Column threshold for table detection (pixels)
`tableRowThresholdRatio`	`f64`	`0.5`	Row threshold ratio for table detection (0.0-1.0)
`useCache`	`bool`	`true`	Enable OCR result caching
`classifyUsePreAdaptedTemplates`	`bool`	`true`	Use pre-adapted templates for character classification
`languageModelNgramOn`	`bool`	`false`	Enable N-gram language model
`tesseditDontBlkrejGoodWds`	`bool`	`true`	Don't reject good words during block-level processing
`tesseditDontRowrejGoodWds`	`bool`	`true`	Don't reject good words during row-level processing
`tesseditEnableDictCorrection`	`bool`	`true`	Enable dictionary correction
`tesseditCharWhitelist`	`[:0]const u8`	`""`	Whitelist of allowed characters (empty = all allowed)
`tesseditCharBlacklist`	`[:0]const u8`	`""`	Blacklist of forbidden characters (empty = none forbidden)
`tesseditUsePrimaryParamsModel`	`bool`	`true`	Use primary language params model
`textordSpaceSizeIsVariable`	`bool`	`true`	Variable-width space detection
`thresholdingMethod`	`bool`	`false`	Use adaptive thresholding method

Methods¶

default()¶

Signature:

pub fn default() TesseractConfig

TextAnnotation¶

Inline text annotation — byte-range based formatting and links.

Annotations reference byte offsets into the node's text content, enabling precise identification of formatted regions.

Field	Type	Default	Description
`start`	`u32`	—	Start byte offset in the node's text content (inclusive).
`end`	`u32`	—	End byte offset in the node's text content (exclusive).
`kind`	`AnnotationKind`	—	Annotation type.

TextExtractionResult¶

Plain text and Markdown extraction result.

Contains the extracted text along with statistics and, for Markdown files, structural elements like headers and links.

Field	Type	Default	Description
`content`	`[:0]const u8`	—	Extracted text content
`lineCount`	`u64`	—	Number of lines
`wordCount`	`u64`	—	Number of words
`characterCount`	`u64`	—	Number of characters
`headers`	`[]const [:0]const u8?`	`null`	Markdown headers (text only, Markdown files only)
`links`	`[]const []const [:0]const u8?`	`null`	Markdown links as (text, URL) tuples (Markdown files only)
`codeBlocks`	`[]const []const [:0]const u8?`	`null`	Code blocks as (language, code) tuples (Markdown files only)

TextMetadata¶

Text/Markdown metadata.

Extracted from plain text and Markdown files. Includes word counts and, for Markdown, structural elements like headers and links.

Field	Type	Default	Description
`lineCount`	`u32`	—	Number of lines in the document
`wordCount`	`u32`	—	Number of words
`characterCount`	`u32`	—	Number of characters
`headers`	`[]const [:0]const u8?`	`[]`	Markdown headers (headings text only, for Markdown files)
`links`	`[]const []const [:0]const u8?`	`[]`	Markdown links as (text, url) tuples (for Markdown files)
`codeBlocks`	`[]const []const [:0]const u8?`	`[]`	Code blocks as (language, code) tuples (for Markdown files)

TokenReductionConfig¶

Field	Type	Default	Description
`level`	`ReductionLevel`	`ReductionLevel.Moderate`	Level (reduction level)
`languageHint`	`[:0]const u8?`	`null`	Language hint
`preserveMarkdown`	`bool`	`false`	Preserve markdown
`preserveCode`	`bool`	`true`	Preserve code
`semanticThreshold`	`f32`	`0.3`	Semantic threshold
`enableParallel`	`bool`	`true`	Enable parallel
`useSimd`	`bool`	`true`	Use simd
`customStopwords`	`std.StringHashMap([]const [:0]const u8)?`	`null`	Custom stopwords
`preservePatterns`	`[]const [:0]const u8`	`[]`	Preserve patterns
`targetReduction`	`f32?`	`null`	Target reduction
`enableSemanticClustering`	`bool`	`false`	Enable semantic clustering

Methods¶

default()¶

Signature:

pub fn default() TokenReductionConfig

TokenReductionOptions¶

Token reduction configuration.

Field	Type	Default	Description
`mode`	`[:0]const u8`	—	Reduction mode: "off", "light", "moderate", "aggressive", "maximum"
`preserveImportantWords`	`bool`	`true`	Preserve important words (capitalized, technical terms)

Methods¶

default()¶

Signature:

pub fn default() TokenReductionOptions

TreeSitterConfig¶

Configuration for tree-sitter language pack integration.

Controls grammar download behavior and code analysis options.

Example (TOML)¶

[tree_sitter]
languages = ["python", "rust"]
groups = ["web"]

[tree_sitter.process]
structure = true
comments = true
docstrings = true

Field	Type	Default	Description
`enabled`	`bool`	`true`	Enable code intelligence processing (default: true). When `false`, tree-sitter analysis is completely skipped even if the config section is present.
`cacheDir`	`[:0]const u8?`	`null`	Custom cache directory for downloaded grammars. When `null`, uses the default: `~/.cache/tree-sitter-language-pack/v{version}/libs/`.
`languages`	`[]const [:0]const u8?`	`null`	Languages to pre-download on init (e.g., `["python", "rust"]`).
`groups`	`[]const [:0]const u8?`	`null`	Language groups to pre-download (e.g., `["web", "systems", "scripting"]`).
`process`	`TreeSitterProcessConfig`	—	Processing options for code analysis.

Methods¶

default()¶

Signature:

pub fn default() TreeSitterConfig

TreeSitterProcessConfig¶

Processing options for tree-sitter code analysis.

Controls which analysis features are enabled when extracting code files.

Field	Type	Default	Description
`structure`	`bool`	`true`	Extract structural items (functions, classes, structs, etc.). Default: true.
`imports`	`bool`	`true`	Extract import statements. Default: true.
`exports`	`bool`	`true`	Extract export statements. Default: true.
`comments`	`bool`	`false`	Extract comments. Default: false.
`docstrings`	`bool`	`false`	Extract docstrings. Default: false.
`symbols`	`bool`	`false`	Extract symbol definitions. Default: false.
`diagnostics`	`bool`	`false`	Include parse diagnostics. Default: false.
`chunkMaxSize`	`u64?`	`null`	Maximum chunk size in bytes. `null` disables chunking.
`contentMode`	`CodeContentMode`	`CodeContentMode.Chunks`	Content rendering mode for code extraction.

Methods¶

default()¶

Signature:

pub fn default() TreeSitterProcessConfig

Uri¶

A URI extracted from a document.

Represents any link, reference, or resource pointer found during extraction. The kind field classifies the URI semantically, while label carries optional human-readable display text.

Field	Type	Default	Description
`url`	`[:0]const u8`	—	The URL or path string.
`label`	`[:0]const u8?`	`null`	Optional display text / label for the link.
`page`	`u32?`	`null`	Optional page number where the URI was found (1-indexed).
`kind`	`UriKind`	—	Semantic classification of the URI.

Validator¶

Trait for validator plugins.

Validators check extraction results for quality, completeness, or correctness. Unlike post-processors, validator errors fail fast - if a validator returns an error, the extraction fails immediately.

Use Cases¶

Quality Gates: Ensure extracted content meets minimum quality standards
Compliance: Verify content meets regulatory requirements
Content Filtering: Reject documents containing unwanted content
Format Validation: Verify extracted content structure
Security Checks: Scan for malicious content

Error Handling¶

Validator errors are fatal - they cause the extraction to fail and bubble up to the caller. Use validators for hard requirements that must be met.

For non-fatal checks, use post-processors instead.

Thread Safety¶

Validators must be thread-safe (Send + Sync).

Methods¶

validate()¶

Validate an extraction result.

Check the extraction result and return Ok(()) if valid, or an error if validation fails.

Returns:

Ok(()) if validation passes
Err(...) if validation fails (extraction will fail)

Errors:

KreuzbergError.Validation - Validation failed
Any other error type appropriate for the failure

Example - Content Length Validation¶

async fn validate(&self, result: &ExtractionResult, config: &ExtractionConfig)
    -> Result<()> {
    let length = result.content.len();

    if length < self.min {
        return Err(KreuzbergError::validation(format!(
            "Content too short: {} < {} characters",
            length, self.min
        )));
    }

    if length > self.max {
        return Err(KreuzbergError::validation(format!(
            "Content too long: {} > {} characters",
            length, self.max
        )));
    }

    Ok(())
}

Example - Quality Score Validation¶

async fn validate(&self, result: &ExtractionResult, config: &ExtractionConfig)
    -> Result<()> {
    // Check if quality_score exists in metadata
    let score = result.metadata
        .additional
        .get("quality_score")
        .and_then(|v| v.as_f64())
        .unwrap_or(0.0);

    if score < self.min_score {
        return Err(KreuzbergError::validation(format!(
            "Quality score too low: {} < {}",
            score, self.min_score
        )));
    }

    Ok(())
}

Example - Security Validation¶

async fn validate(&self, result: &ExtractionResult, config: &ExtractionConfig)
    -> Result<()> {
    // Check for blocked patterns
    for pattern in &self.blocked_patterns {
        if result.content.contains(pattern) {
            return Err(KreuzbergError::validation(format!(
                "Content contains blocked pattern: {}",
                pattern
            )));
        }
    }

    Ok(())
}

Signature:

pub fn validate(self: *const Validator, result: ExtractionResult, config: ExtractionConfig) Error!void

shouldValidate()¶

Optional: Check if this validator should run for a given result.

Allows conditional validation based on MIME type, metadata, or content. Defaults to true (always run).

Returns:

true if the validator should run, false to skip.

Signature:

pub fn shouldValidate(self: *const Validator, result: ExtractionResult, config: ExtractionConfig) bool

priority()¶

Optional: Get the validation priority.

Higher priority validators run first. Useful for ordering validation checks (e.g., run cheap validations before expensive ones).

Default priority is 50.

Returns:

Priority value (higher = runs earlier).

Signature:

pub fn priority(self: *const Validator) i32

XlsxAppProperties¶

Application properties from docProps/app.xml for XLSX

Contains Excel-specific document metadata.

Field	Type	Default	Description
`application`	`[:0]const u8?`	`null`	Application name (e.g., "Microsoft Excel")
`appVersion`	`[:0]const u8?`	`null`	Application version
`docSecurity`	`i32?`	`null`	Document security level
`scaleCrop`	`bool?`	`null`	Scale crop flag
`linksUpToDate`	`bool?`	`null`	Links up to date flag
`sharedDoc`	`bool?`	`null`	Shared document flag
`hyperlinksChanged`	`bool?`	`null`	Hyperlinks changed flag
`company`	`[:0]const u8?`	`null`	Company name
`worksheetNames`	`[]const [:0]const u8`	`[]`	Worksheet names

XmlExtractionResult¶

XML extraction result.

Contains extracted text content from XML files along with structural statistics about the XML document.

Field	Type	Default	Description
`content`	`[:0]const u8`	—	Extracted text content (XML structure filtered out)
`elementCount`	`u64`	—	Total number of XML elements processed
`uniqueElements`	`[]const [:0]const u8`	—	List of unique element names found (sorted)

XmlMetadata¶

XML metadata extracted during XML parsing.

Provides statistics about XML document structure.

Field	Type	Default	Description
`elementCount`	`u32`	—	Total number of XML elements processed
`uniqueElements`	`[]const [:0]const u8`	`[]`	List of unique element tag names (sorted)

YakeParams¶

YAKE-specific parameters.

Field	Type	Default	Description
`windowSize`	`u64`	`2`	Window size for co-occurrence analysis (default: 2). Controls the context window for computing co-occurrence statistics.

Methods¶

default()¶

Signature:

pub fn default() YakeParams

YearRange¶

Year range for bibliographic metadata.

Field	Type	Default	Description
`min`	`u32?`	`null`	Min
`max`	`u32?`	`null`	Max
`years`	`[]const u32`	`/* serde(default) */`	Years

Enums¶

ExecutionProviderType¶

ONNX Runtime execution provider type.

Determines which hardware backend is used for model inference. Auto (default) selects the best available provider per platform.

Value	Description
`Auto`	Auto-select: CoreML on macOS, CUDA on Linux, CPU elsewhere.
`Cpu`	CPU execution provider (always available).
`CoreMl`	Apple CoreML (macOS/iOS Neural Engine + GPU).
`Cuda`	NVIDIA CUDA GPU acceleration.
`TensorRt`	NVIDIA TensorRT (optimized CUDA inference).

OutputFormat¶

Output format for extraction results.

Controls the format of the content field in ExtractionResult. When set to Markdown, Djot, or Html, the output uses that format. Plain returns the raw extracted text. Structured returns JSON with full OCR element data including bounding boxes and confidence scores.

Value	Description
`Plain`	Plain text content only (default)
`Markdown`	Markdown format
`Djot`	Djot markup format
`Html`	HTML format
`Json`	JSON tree format with heading-driven sections.
`Structured`	Structured JSON format with full OCR element metadata.
`Custom`	Custom renderer registered via the RendererRegistry. The string is the renderer name (e.g., "docx", "latex"). — Fields: `0`: `[:0]const u8`

HtmlTheme¶

Built-in HTML theme selection.

Value	Description
`Default`	Sensible defaults: system font stack, neutral colours, readable line measure. CSS custom properties (`--kb-*`) are all defined so user CSS can override individual values.
`GitHub`	GitHub Markdown-inspired palette and spacing.
`Dark`	Dark background, light text.
`Light`	Minimal light theme with generous whitespace.
`Unstyled`	No built-in stylesheet emitted. CSS custom properties are still defined on `:root` so user stylesheets can reference `var(--kb-*)` tokens.

TableModel¶

Which table structure recognition model to use.

Controls the model used for table cell detection within layout-detected table regions. Wire format is snake_case in all serializers (JSON, TOML, YAML).

Value	Description
`Tatr`	TATR (Table Transformer) -- default, 30MB, DETR-based row/column detection.
`SlanetWired`	SLANeXT wired variant -- 365MB, optimized for bordered tables.
`SlanetWireless`	SLANeXT wireless variant -- 365MB, optimized for borderless tables.
`SlanetPlus`	SLANet-plus -- 7.78MB, lightweight general-purpose.
`SlanetAuto`	Classifier-routed SLANeXT: auto-select wired/wireless per table. Uses PP-LCNet classifier (6.78MB) + both SLANeXT variants (730MB total).
`Disabled`	Disable table structure model inference entirely; use heuristic path only.

ChunkerType¶

Type of text chunker to use.

Variants¶

Text - Generic text splitter, splits on whitespace and punctuation
Markdown - Markdown-aware splitter, preserves formatting and structure
Yaml - YAML-aware splitter, creates one chunk per top-level key
Semantic - Topic-aware chunker. With an EmbeddingConfig, splits at embedding-based topic shifts tuned by topic_threshold (default 0.75, lower = more splits). Without an embedding, falls back to a structural-boundary heuristic (ALL-CAPS headers, numbered sections, blank-line paragraphs) and merges groups into chunks capped at max_characters (default 1000). topic_threshold has no effect in the fallback path. For best results, pair with an embedding model.

Value	Description
`Text`	Text format
`Markdown`	Markdown format
`Yaml`	Yaml format
`Semantic`	Semantic

ChunkSizing¶

How chunk size is measured.

Defaults to Characters (Unicode character count). When using token-based sizing, chunks are sized by token count according to the specified tokenizer.

Token-based sizing uses HuggingFace tokenizers loaded at runtime. Any tokenizer available on HuggingFace Hub can be used, including OpenAI-compatible tokenizers (e.g., Xenova/gpt-4o, Xenova/cl100k_base).

Value	Description
`Characters`	Size measured in Unicode characters (default).
`Tokenizer`	Size measured in tokens from a HuggingFace tokenizer. — Fields: `model`: `[:0]const u8`, `cacheDir`: `[:0]const u8`

EmbeddingModelType¶

Embedding model types supported by Kreuzberg.

Value	Description
`Preset`	Use a preset model configuration (recommended) — Fields: `name`: `[:0]const u8`
`Custom`	Use a custom ONNX model from HuggingFace — Fields: `modelId`: `[:0]const u8`, `dimensions`: `u64`
`Llm`	Provider-hosted embedding model via liter-llm. Uses the model specified in the nested `LlmConfig` (e.g., `"openai/text-embedding-3-small"`). — Fields: `llm`: `LlmConfig`
`Plugin`	In-process embedding backend registered via the plugin system. The caller registers an `EmbeddingBackend` once (e.g. a wrapper around an already-loaded `llama-cpp-python`, `sentence-transformers`, or tuned ONNX model), then references it by name in config. Kreuzberg calls back into the registered backend during chunking and standalone embed requests — no HuggingFace download, no ONNX Runtime requirement, no HTTP sidecar. When this variant is selected, only the following `EmbeddingConfig` fields apply: `normalize` (post-call L2 normalization) and `max_embed_duration_secs` (dispatcher timeout). Model-loading fields (`batch_size`, `cache_dir`, `show_download_progress`, `acceleration`) are ignored — the host owns the model lifecycle. Semantic chunking falls back to `ChunkingConfig.max_characters` when this variant is used, since there is no preset to look a chunk-size ceiling up against — size your context window via `max_characters` directly. See `register_embedding_backend`. — Fields: `name`: `[:0]const u8`

CodeContentMode¶

Content rendering mode for code extraction.

Controls how extracted code content is represented in the content field of ExtractionResult.

Value	Description
`Chunks`	Use TSLP semantic chunks as content (default).
`Raw`	Use raw source code as content.
`Structure`	Emit function/class headings + docstrings (no code bodies).

ListType¶

Type of list detection.

Value	Description
`Bullet`	Bullet points (-, *, •, etc.)
`Numbered`	Numbered lists (1., 2., etc.)
`Lettered`	Lettered lists (a., b., A., B., etc.)
`Indented`	Indented items

FracType¶

Value	Description
`Bar`	Bar
`NoBar`	No bar
`Linear`	Linear
`Skewed`	Skewed

OcrBackendType¶

OCR backend types.

Value	Description
`Tesseract`	Tesseract OCR (native Rust binding)
`EasyOcr`	EasyOCR (Python-based, via FFI)
`PaddleOcr`	PaddleOCR (Python-based, via FFI)
`Custom`	Custom/third-party OCR backend

ProcessingStage¶

Processing stages for post-processors.

Post-processors are executed in stage order (Early → Middle → Late). Use stages to control the order of post-processing operations.

Value	Description
`Early`	Early stage - foundational processing. Use for: - Language detection - Character encoding normalization - Entity extraction (NER) - Text quality scoring
`Middle`	Middle stage - content transformation. Use for: - Keyword extraction - Token reduction - Text summarization - Semantic analysis
`Late`	Late stage - final enrichment. Use for: - Custom user hooks - Analytics/logging - Final validation - Output formatting

ReductionLevel¶

Value	Description
`Off`	Off
`Light`	Light
`Moderate`	Moderate
`Aggressive`	Aggressive
`Maximum`	Maximum

PdfAnnotationType¶

Type of PDF annotation.

Value	Description
`Text`	Sticky note / text annotation
`Highlight`	Highlighted text region
`Link`	Hyperlink annotation
`Stamp`	Rubber stamp annotation
`Underline`	Underline text markup
`StrikeOut`	Strikeout text markup
`Other`	Any other annotation type

BlockType¶

Types of block-level elements in Djot.

Value	Description
`Paragraph`	Paragraph element
`Heading`	Heading element
`Blockquote`	Blockquote element
`CodeBlock`	Code block
`ListItem`	List item
`OrderedList`	Ordered list
`BulletList`	Bullet list
`TaskList`	Task list
`DefinitionList`	Definition list
`DefinitionTerm`	Definition term
`DefinitionDescription`	Definition description
`Div`	Div
`Section`	Section element
`ThematicBreak`	Thematic break
`RawBlock`	Raw block
`MathDisplay`	Math display

InlineType¶

Types of inline elements in Djot.

Value	Description
`Text`	Text format
`Strong`	Strong
`Emphasis`	Emphasis
`Highlight`	Highlight
`Subscript`	Subscript
`Superscript`	Superscript
`Insert`	Insert
`Delete`	Delete
`Code`	Code
`Link`	Link
`Image`	Image element
`Span`	Span
`Math`	Math
`RawInline`	Raw inline
`FootnoteRef`	Footnote ref
`Symbol`	Symbol

RelationshipKind¶

Semantic kind of a relationship between document elements.

Value	Description
`FootnoteReference`	Footnote marker -> footnote definition.
`CitationReference`	Citation marker -> bibliography entry.
`InternalLink`	Internal anchor link (`#id`) -> target heading/element.
`Caption`	Caption paragraph -> figure/table it describes.
`Label`	Label -> labeled element (HTML `<label for>`, LaTeX `\label{}`).
`TocEntry`	TOC entry -> target section.
`CrossReference`	Cross-reference (LaTeX `\ref{}`, DOCX cross-reference field).

ContentLayer¶

Content layer classification for document nodes.

Replaces separate body/furniture arrays with per-node granularity.

Value	Description
`Body`	Main document body content.
`Header`	Page/section header (running header).
`Footer`	Page/section footer (running footer).
`Footnote`	Footnote content.

NodeContent¶

Tagged enum for node content. Each variant carries only type-specific data.

Uses #[serde(tag = "node_type")] to avoid "type" keyword collision in Go/Java/TypeScript bindings.

Value	Description
`Title`	Document title. — Fields: `text`: `[:0]const u8`
`Heading`	Section heading with level (1-6). — Fields: `level`: `u8`, `text`: `[:0]const u8`
`Paragraph`	Body text paragraph. — Fields: `text`: `[:0]const u8`
`List`	List container — children are `ListItem` nodes. — Fields: `ordered`: `bool`
`ListItem`	Individual list item. — Fields: `text`: `[:0]const u8`
`Table`	Table with structured cell grid. — Fields: `grid`: `TableGrid`
`Image`	Image reference. — Fields: `description`: `[:0]const u8`, `imageIndex`: `u32`, `src`: `[:0]const u8`
`Code`	Code block. — Fields: `text`: `[:0]const u8`, `language`: `[:0]const u8`
`Quote`	Block quote — container, children carry the quoted content.
`Formula`	Mathematical formula / equation. — Fields: `text`: `[:0]const u8`
`Footnote`	Footnote reference content. — Fields: `text`: `[:0]const u8`
`Group`	Logical grouping container (section, key-value area). `heading_level` + `heading_text` capture the section heading directly rather than relying on a first-child positional convention. — Fields: `label`: `[:0]const u8`, `headingLevel`: `u8`, `headingText`: `[:0]const u8`
`PageBreak`	Page break marker.
`Slide`	Presentation slide container — children are the slide's content nodes. — Fields: `number`: `u32`, `title`: `[:0]const u8`
`DefinitionList`	Definition list container — children are `DefinitionItem` nodes.
`DefinitionItem`	Individual definition list entry with term and definition. — Fields: `term`: `[:0]const u8`, `definition`: `[:0]const u8`
`Citation`	Citation or bibliographic reference. — Fields: `key`: `[:0]const u8`, `text`: `[:0]const u8`
`Admonition`	Admonition / callout container (note, warning, tip, etc.). Children carry the admonition body content. — Fields: `kind`: `[:0]const u8`, `title`: `[:0]const u8`
`RawBlock`	Raw block preserved verbatim from the source format. Used for content that cannot be mapped to a semantic node type (e.g. JSX in MDX, raw LaTeX in markdown, embedded HTML). — Fields: `format`: `[:0]const u8`, `content`: `[:0]const u8`
`MetadataBlock`	Structured metadata block (email headers, YAML frontmatter, etc.). — Fields: `entries`: `[]const []const [:0]const u8`

AnnotationKind¶

Types of inline text annotations.

Value	Description
`Bold`	Bold
`Italic`	Italic
`Underline`	Underline
`Strikethrough`	Strikethrough
`Code`	Code
`Subscript`	Subscript
`Superscript`	Superscript
`Link`	Link — Fields: `url`: `[:0]const u8`, `title`: `[:0]const u8`
`Highlight`	Highlighted text (PDF highlights, HTML `<mark>`).
`Color`	Text color (CSS-compatible value, e.g. "#ff0000", "red"). — Fields: `value`: `[:0]const u8`
`FontSize`	Font size with units (e.g. "12pt", "1.2em", "16px"). — Fields: `value`: `[:0]const u8`
`Custom`	Extensible annotation for format-specific styling. — Fields: `name`: `[:0]const u8`, `value`: `[:0]const u8`

ExtractionMethod¶

How the extracted text was produced.

Value	Description
`Native`	Native
`Ocr`	Ocr
`Mixed`	Mixed

ChunkType¶

Semantic structural classification of a text chunk.

Assigned by the heuristic classifier in chunking.classifier. Defaults to Unknown when no rule matches. Designed to be extended in future versions without breaking changes.

Value	Description
`Heading`	Section heading or document title.
`PartyList`	Party list: names, addresses, and signatories.
`Definitions`	Definition clause ("X means…", "X shall mean…").
`OperativeClause`	Operative clause containing legal/contractual action verbs.
`SignatureBlock`	Signature block with signatures, names, and dates.
`Schedule`	Schedule, annex, appendix, or exhibit section.
`TableLike`	Table-like content with aligned columns or repeated patterns.
`Formula`	Mathematical formula or equation.
`CodeBlock`	Code block or preformatted content.
`Image`	Embedded or referenced image content.
`OrgChart`	Organizational chart or hierarchy diagram.
`Diagram`	Diagram, figure, or visual illustration.
`Unknown`	Unclassified or mixed content.

ImageKind¶

Heuristic classification of what an image likely depicts.

Value	Description
`Photograph`	Photographic image (natural scene, photograph)
`Diagram`	Technical or schematic diagram
`Chart`	Chart, graph, or plot
`Drawing`	Freehand or technical drawing
`TextBlock`	Text-heavy image (scanned text, document)
`Decoration`	Decorative element or border
`Logo`	Logo or brand mark
`Icon`	Small icon
`TileFragment`	Fragment of a larger tiled image (tile of a technical drawing)
`Mask`	Mask or transparency map
`Unknown`	Could not classify with reasonable confidence

ResultFormat¶

Result-shape selection for extraction results.

Distinct from OutputFormat (which controls rendering — Plain, Markdown, HTML, etc.). ResultFormat controls the shape of the result: a unified content blob vs. an element-based decomposition.

Value	Description
`Unified`	Unified format with all content in `content` field
`ElementBased`	Element-based format with semantic element extraction

ElementType¶

Semantic element type classification.

Categorizes text content into semantic units for downstream processing. Supports the element types commonly found in Unstructured documents.

Value	Description
`Title`	Document title
`NarrativeText`	Main narrative text body
`Heading`	Section heading
`ListItem`	List item (bullet, numbered, etc.)
`Table`	Table element
`Image`	Image element
`PageBreak`	Page break marker
`CodeBlock`	Code block
`BlockQuote`	Block quote
`Footer`	Footer text
`Header`	Header text

FormatMetadata¶

Format-specific metadata (discriminated union).

Only one format type can exist per extraction result. This provides type-safe, clean metadata without nested optionals.

Value	Description
`Pdf`	Pdf format — Fields: `0`: `PdfMetadata`
`Docx`	Docx format — Fields: `0`: `DocxMetadata`
`Excel`	Excel — Fields: `0`: `ExcelMetadata`
`Email`	Email — Fields: `0`: `EmailMetadata`
`Pptx`	Pptx format — Fields: `0`: `PptxMetadata`
`Archive`	Archive — Fields: `0`: `ArchiveMetadata`
`Image`	Image element — Fields: `0`: `ImageMetadata`
`Xml`	Xml format — Fields: `0`: `XmlMetadata`
`Text`	Text format — Fields: `0`: `TextMetadata`
`Html`	Preserve as HTML `<mark>` tags — Fields: `0`: `HtmlMetadata`
`Ocr`	Ocr — Fields: `0`: `OcrMetadata`
`Csv`	Csv format — Fields: `0`: `CsvMetadata`
`Bibtex`	Bibtex — Fields: `0`: `BibtexMetadata`
`Citation`	Citation — Fields: `0`: `CitationMetadata`
`FictionBook`	Fiction book — Fields: `0`: `FictionBookMetadata`
`Dbf`	Dbf — Fields: `0`: `DbfMetadata`
`Jats`	Jats — Fields: `0`: `JatsMetadata`
`Epub`	Epub format — Fields: `0`: `EpubMetadata`
`Pst`	Pst — Fields: `0`: `PstMetadata`
`Code`	Code — Fields: `0`: `[:0]const u8`

TextDirection¶

Text direction enumeration for HTML documents.

Value	Description
`LeftToRight`	Left-to-right text direction
`RightToLeft`	Right-to-left text direction
`Auto`	Automatic text direction detection

LinkType¶

Link type classification.

Value	Description
`Anchor`	Anchor link (#section)
`Internal`	Internal link (same domain)
`External`	External link (different domain)
`Email`	Email link (mailto:)
`Phone`	Phone link (tel:)
`Other`	Other link type

ImageType¶

Image type classification.

Value	Description
`DataUri`	Data URI image
`InlineSvg`	Inline SVG
`External`	External image URL
`Relative`	Relative path image

StructuredDataType¶

Structured data type classification.

Value	Description
`JsonLd`	JSON-LD structured data
`Microdata`	Microdata
`RDFa`	RDFa

OcrBoundingGeometry¶

Bounding geometry for an OCR element.

Supports both axis-aligned rectangles (from Tesseract) and 4-point quadrilaterals (from PaddleOCR and rotated text detection).

Value	Description
`Rectangle`	Axis-aligned bounding box (typical for Tesseract output). — Fields: `left`: `u32`, `top`: `u32`, `width`: `u32`, `height`: `u32`
`Quadrilateral`	4-point quadrilateral for rotated/skewed text (PaddleOCR). Points are in clockwise order starting from top-left: `[top_left, top_right, bottom_right, bottom_left]` — Fields: `points`: `[:0]const u8`

OcrElementLevel¶

Hierarchical level of an OCR element.

Maps to Tesseract's page segmentation hierarchy and provides equivalent semantics for PaddleOCR.

Value	Description
`Word`	Individual word
`Line`	Line of text (default for PaddleOCR)
`Block`	Paragraph or text block
`Page`	Page-level element

PageUnitType¶

Type of paginated unit in a document.

Distinguishes between different types of "pages" (PDF pages, presentation slides, spreadsheet sheets).

Value	Description
`Page`	Standard document pages (PDF, DOCX, images)
`Slide`	Presentation slides (PPTX, ODP)
`Sheet`	Spreadsheet sheets (XLSX, ODS)

UriKind¶

Semantic classification of an extracted URI.

Value	Description
`Hyperlink`	A clickable hyperlink (web URL, file link).
`Image`	An image or media resource reference.
`Anchor`	An internal anchor or cross-reference target.
`Citation`	A citation or bibliographic reference (DOI, academic ref).
`Reference`	A general reference (e.g. `\ref{}` in LaTeX, `:ref:` in RST).
`Email`	An email address (`mailto:` link or bare email).

KeywordAlgorithm¶

Keyword algorithm selection.

Value	Description
`Yake`	YAKE (Yet Another Keyword Extractor) - statistical approach
`Rake`	RAKE (Rapid Automatic Keyword Extraction) - co-occurrence based

PsmMode¶

Page Segmentation Mode for Tesseract OCR

Value	Description
`OsdOnly`	Osd only
`AutoOsd`	Auto osd
`AutoOnly`	Auto only
`Auto`	Auto
`SingleColumn`	Single column
`SingleBlockVertical`	Single block vertical
`SingleBlock`	Single block
`SingleLine`	Single line
`SingleWord`	Single word
`CircleWord`	Circle word
`SingleChar`	Single char

PaddleLanguage¶

Supported languages in PaddleOCR.

Maps user-friendly language codes to paddle-ocr-rs language identifiers.

Value	Description
`English`	English
`Chinese`	Simplified Chinese
`Japanese`	Japanese
`Korean`	Korean
`German`	German
`French`	French
`Latin`	Latin script (covers most European languages)
`Cyrillic`	Cyrillic (Russian and related)
`TraditionalChinese`	Traditional Chinese
`Thai`	Thai
`Greek`	Greek
`EastSlavic`	East Slavic (Russian, Ukrainian, Belarusian)
`Arabic`	Arabic (Arabic, Persian, Urdu)
`Devanagari`	Devanagari (Hindi, Marathi, Sanskrit, Nepali)
`Tamil`	Tamil
`Telugu`	Telugu

LayoutClass¶

The 17 canonical document layout classes.

All model backends (RT-DETR, YOLO, etc.) map their native class IDs to this shared set. Models with fewer classes (DocLayNet: 11, PubLayNet: 5) map to the closest equivalent.

Wire format is snake_case in all serializers (JSON, TOML, YAML).

Value	Description
`Caption`	Caption element
`Footnote`	Footnote element
`Formula`	Formula
`ListItem`	List item
`PageFooter`	Page footer
`PageHeader`	Page header
`Picture`	Picture
`SectionHeader`	Section header
`Table`	Table element
`Text`	Text format
`Title`	Title element
`DocumentIndex`	Document index
`Code`	Code
`CheckboxSelected`	Checkbox selected
`CheckboxUnselected`	Checkbox unselected
`Form`	Form
`KeyValueRegion`	Key value region

Errors¶

KreuzbergError¶

Main error type for all Kreuzberg operations.

All errors in Kreuzberg use this enum, which preserves error chains and provides context for debugging.

Variants¶

Io - File system and I/O errors (always bubble up)
Parsing - Document parsing errors (corrupt files, unsupported features)
Ocr - OCR processing errors
Validation - Input validation errors (invalid paths, config, parameters)
Cache - Cache operation errors (non-fatal, can be ignored)
ImageProcessing - Image manipulation errors
Serialization - JSON/MessagePack serialization errors
MissingDependency - Missing optional dependencies (tesseract, etc.)
Plugin - Plugin-specific errors
LockPoisoned - Mutex/RwLock poisoning (should not happen in normal operation)
UnsupportedFormat - Unsupported MIME type or file format
Other - Catch-all for uncommon errors

Variant	Description
`Io`	IO error:
`Parsing`	Parsing error:
`Ocr`	OCR error:
`Validation`	Validation error:
`Cache`	Cache error:
`ImageProcessing`	Image processing error:
`Serialization`	Serialization error:
`MissingDependency`	Missing dependency:
`Plugin`	Plugin error in '{plugin_name}':
`LockPoisoned`	Lock poisoned:
`UnsupportedFormat`	Unsupported format:
`Embedding`	Embedding error:
`Timeout`	Extraction timed out after {elapsed_ms}ms (limit: {limit_ms}ms)
`Cancelled`	Extraction cancelled
`Security`	Security violation:
`Other`	{0}

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