Supported File Formats

OpenContracts accepts several document formats for upload. Each format is routed to a specific parser that extracts text, structure, and layout information.

Core Formats

Format	Extension	MIME Type	Default Parser
PDF	.pdf	application/pdf	DoclingParser (ML-based REST microservice)
Plain Text	.txt	text/plain	TxtParser (sentence-level splitting via spaCy)
Word	.docx	application/vnd.openxmlformats-officedocument.wordprocessingml.document	DocxodusServiceParser (REST microservice)

These are the formats registered in the pipeline's FileTypeEnum and are available for both single uploads and bulk imports.

Legacy MIME Aliases

The system also accepts application/txt as an alias for text/plain for backward compatibility.

Parser Details

DoclingParser (PDF)

The default parser for PDFs uses the Docling ML microservice for advanced layout extraction:

• Extracts text tokens with bounding boxes (PAWLs format)
• Detects document structure (headings, sections, tables, figures)
• Creates structural annotations automatically
• Supports automatic chunking for large PDFs
• Handles both OCR'd and non-OCR'd PDFs (performs its own OCR)
• Optional image extraction

LlamaParseParser (PDF)

An alternative PDF parser using the LlamaParse cloud API:

• Supports 17 element types (Title, Section Header, Heading, Text Block, Table, Figure, Image, List, etc.)
• Multimodal support for complex layouts
• Requires a LLAMAPARSE_API_KEY environment variable

TxtParser (Plain Text)

A simple parser for text files:

• Splits text into sentences using spaCy NLP
• Creates SPAN_LABEL annotations for each sentence
• Documents are treated as single-page (no PAWLs data)

DocxodusServiceParser (Word)

Handles Word documents via the Docxodus microservice:

• Character-offset based annotations (aligned with WASM frontend rendering)
• Extracts structural layout from Word formatting
• Max file size: 50MB (before base64 encoding)

Dynamic Format Discovery

The set of supported formats is not hardcoded on the frontend. The backend exposes a supportedMimeTypes GraphQL query that returns the currently registered formats along with their pipeline coverage:

• Whether a parser is available
• Whether an embedder is available
• Whether a thumbnailer is available
• Whether the format is "fully supported" (all three stages covered)

This means that adding a new parser for a new file type automatically makes it available in the upload UI without frontend changes.

Processing Pipeline

Every uploaded document goes through a three-stage pipeline:

1. Parsing -- Extracts text, tokens, bounding boxes, and structural annotations
2. Thumbnail generation -- Creates a visual preview image
3. Embedding -- Generates vector embeddings for semantic search

Documents are not available for viewing or annotation until parsing completes. A loading indicator is shown on the document card during processing.

For full pipeline architecture details, see the Pipeline Overview.