donkit-read-engine 0.5.3

Document loading helpers for Donkit RagOps

donkit-read-engine

Document extraction library for Donkit RagOps. Reads 20+ file formats and produces structured, page-level JSON — with tables as Markdown, headings preserved, and optional LLM-powered image descriptions. Images extracted from documents can be saved locally or uploaded to S3 for use in downstream retrieval.

PyPI: pip install donkit-read-engine Python: 3.12 – 3.13 License: MIT

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Features

• Extracts text, tables, headings, captions, code blocks from PDF, DOCX, PPTX, XLSX, HTML, Markdown, LaTeX, images, and more
• Three processing pipelines: Docling-only, Docling + LLM, or pure LLM vision
• Extracts and saves document images (PNG) with page association — ready for multimodal retrieval
• S3 support: uploads JSON result and images to S3 with a single s3_output_prefix parameter
• Fully async (aread_document) with sync wrapper (read_document)
• LLM token usage tracking per document

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Installation

pip install donkit-read-engine

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Quick Start

Text only (no LLM)

from donkit.read_engine.read_engine import DonkitReader

reader = DonkitReader(reading_pipeline="docling")
result = reader.read_document("report.pdf")

print(result.output_path)   # ./processed/report.json
print(result.page_count)    # 42

With LLM image descriptions + save images locally

from donkit.llm import ModelFactory
from donkit.read_engine.read_engine import DonkitReader

llm_model = ModelFactory.create_model("openai", "gpt-4o-mini", {"api_key": "sk-..."})

reader = DonkitReader(
    llm_model=llm_model,
    reading_pipeline="docling_llm",  # default
)

result = reader.read_document("report.pdf", output_dir="./output")
# ./output/report.json
# ./output/images_report/page0001_img0000.png
# ./output/images_report/page0003_img0001.png

print(result.images_dir)              # ./output/images_report
print(result.total_llm_requests)      # 5
print(result.total_prompt_tokens)     # 3200

Async

result = await reader.aread_document("report.pdf", output_dir="./output")

With S3 output

Pass s3_service at construction and s3_output_prefix per call. The JSON result and all extracted images are uploaded; the local staging directory is cleaned up automatically.

from donkit.read_engine.utils.s3 import S3Credentials, S3Service
from donkit.read_engine.read_engine import DonkitReader

s3 = S3Service(S3Credentials(
    access_key_id="...",
    secret_access_key="...",
    region_name="us-east-1",
    endpoint_url="https://s3.amazonaws.com",
    bucket_name="my-bucket",
))

reader = DonkitReader(
    llm_model=llm_model,
    reading_pipeline="docling_llm",
    s3_service=s3,
)

result = await reader.aread_document(
    "report.pdf",
    s3_output_prefix="experiments/exp123/reading",
)
# result.output_path  = "experiments/exp123/reading/report.json"   (S3 key)
# result.images_dir   = "experiments/exp123/reading/images_report" (S3 prefix)

S3 layout:

experiments/exp123/reading/
  report.json
  images_report/
    page0001_img0000.png
    page0003_img0001.png

Note: when S3 is used, result.output_path and result.images_dir contain S3 keys, not local paths.

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Pipelines

Pipeline	Description	Requires llm_model	Saves images
docling_llm	Docling parses the document; LLM describes each image (up to 15 concurrent calls). Images saved to disk / S3.	Yes	Yes
docling	Docling only; built-in VLM describes images. No images saved to disk.	No	No
llm	PDF pages rasterized and sent entirely to LLM vision. Non-PDF formats via Docling. No images saved.	Yes	No

Image saving (images_dir) is only supported in the docling_llm pipeline.

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Supported Formats

Via Docling (primary engine)

Extension	Format
.pdf	PDF
.docx	Word
.pptx	PowerPoint
.xlsx, .csv	Excel / CSV
.html	HTML
.md, .txt	Markdown / plain text
.tex	LaTeX
.asciidoc	AsciiDoc
.vtt	WebVTT subtitles
.png, .jpg, .jpeg, .gif, .webp, .tiff	Images

Legacy readers

Extension	Format
.json	JSON documents
.xls	Legacy Excel (pre-2007)

---

Output Format

Every pipeline writes a single JSON file:

{
  "content": [
    {
      "page": 1,
      "type": "Text",
      "content": "# Title\n\nParagraph text...\n\n| Col1 | Col2 |\n|---|---|\n| A | B |",
      "images": [
        "./output/images_report/page0001_img0000.png"
      ]
    },
    {
      "page": 2,
      "type": "Text",
      "content": "More text on page two."
    }
  ]
}

• page — 1-based page number from the source document
• content — Markdown-formatted text: headings, tables, lists, code blocks, captions
• images — list of saved image paths (local paths or S3 keys); only present when images were extracted

Page headers, footers, and decorative images (detected by LLM and answered SKIP) are excluded from content but images are still saved.

---

API Reference

DonkitReader

class DonkitReader:
    def __init__(
        self,
        output_format: Literal["json", "text", "md"] = "json",
        progress_callback: Callable[[int, int, str | None], None] | None = None,
        llm_model: LLMModelAbstract | None = None,
        reading_pipeline: str = "docling_llm",
        s3_service: S3Service | None = None,
    ) -> None

Parameter	Type	Default	Description
output_format	"json" / "text" / "md"	"json"	Format hint passed to the image analysis service
progress_callback	Callable	None	(current, total, message) — called per page in llm pipeline
llm_model	LLMModelAbstract	None	LLM for image descriptions. Required for docling_llm and llm
reading_pipeline	str	"docling_llm"	"docling_llm", "docling", or "llm"
s3_service	S3Service	None	If set, results are uploaded to S3 when s3_output_prefix is provided

def read_document(
    self,
    file_path: str,
    output_dir: str | None = None,
    s3_output_prefix: str | None = None,
) -> ReadDocumentResult

async def aread_document(
    self,
    file_path: str,
    output_dir: str | None = None,
    s3_output_prefix: str | None = None,
) -> ReadDocumentResult

Parameter	Description
file_path	Path to the source document
output_dir	Local directory for results. Defaults to processed/ next to the source file. When S3 is used and output_dir is None, a temporary directory is created and cleaned up automatically
s3_output_prefix	S3 key prefix for all output artifacts (JSON + images). Requires s3_service set at construction

ReadDocumentResult

@dataclass
class ReadDocumentResult:
    output_path: str                           # Local path to JSON, or S3 key when S3 is used
    page_count: int                            # Number of unique pages
    images_dir: str | None                     # Local images dir, or S3 prefix, or None
    total_llm_requests: int
    total_prompt_tokens: int
    total_completion_tokens: int
    page_split_duration_ms: int | None
    reading_duration_ms: int | None
    gc_duration_ms: int | None
    json_serialize_duration_ms: int | None
    rasterize_duration_ms: int | None

S3Service / S3Credentials

@dataclass
class S3Credentials:
    access_key_id: str
    secret_access_key: str
    region_name: str
    endpoint_url: str
    bucket_name: str

class S3Service:
    def __init__(self, credentials: S3Credentials)
    async def download_file(self, s3_path: str, local_path: str) -> None
    async def upload_file(self, local_path: str, s3_path: str) -> None
    async def upload_content(self, s3_path: str, content: bytes) -> None

---

CLI

# Single file
donkit-read-engine report.pdf

# Directory (recursive)
donkit-read-engine ./documents/

# With OCR settings (unstructured backend)
donkit-read-engine scan.pdf --pdf-strategy hi_res --ocr-lang rus+eng

Argument	Values	Default
file_path	file or directory	—
--output-type	text, json, markdown	json
--pdf-strategy	fast, hi_res, ocr_only, auto	—
--ocr-lang	e.g. rus+eng	—

The CLI uses the docling pipeline (no LLM).

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Environment Variables

Variable	Default	Description
UNSTRUCTURED_STRATEGY	hi_res	PDF OCR strategy for the unstructured backend
UNSTRUCTURED_OCR_LANG	rus+eng	OCR language codes

LLM credentials are not read from environment. Pass llm_model explicitly.

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Dependencies

Package	Purpose
docling	Primary document conversion engine
pymupdf	PDF rasterization (llm pipeline)
unstructured[pdf]	PDF OCR with Tesseract
python-docx, python-pptx	Office format parsing
pandas	Excel / CSV processing
pillow	Image extraction and encoding
donkit-llm	LLM provider abstraction
aioboto3	Async S3 client
json-repair	Fix malformed JSON from LLM output
loguru	Structured logging