Privacy-first document intelligence engine for production RAG pipelines.

Parse PDFs, DOCX, PPTX, XLSX & CSV → validated, AI-ready chunks with HITL review.

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Features

Feature	Detail
Multi-format extraction	PDF, DOCX, PPTX, XLSX, CSV via Docling
Hybrid chunking	Token-aware, heading-hierarchy-aware, table-aware
HITL review	Human-in-the-Loop block & chunk editing before embedding
LangGraph HITL	approve / edit / reject workflow with LangGraph interrupt() and MongoDB checkpointer
3-layer memory	Short-term turns + rolling summary + long-term facts
Multi-provider LLM	OpenAI, Gemini, Groq, OpenRouter
Multi-backend vectors	Chroma, FAISS, Qdrant
Production-ready API	FastAPI + Motor (MongoDB) + ARQ + Redis (Queue & Rate Limiting)
Enterprise Security	Tenant isolation, Role-Based Access Control (RBAC), and CORS
LangChain adapters	Drop-in BaseRetriever and LlamaIndex QueryEngine
Privacy-first	All processing runs locally; no data leaves your infra

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Installation

Quick install (recommended)

pip install "longparser[gpu]"

Includes everything — server, embeddings, vector DB, OCR, LangChain, LlamaIndex. Works on CPU machines too; torch just runs in CPU mode automatically.

Core SDK only (no server, no torch)

pip install longparser

Pick only what you need

Extra	What it adds
server	FastAPI + MongoDB + Redis + LangChain chat
embeddings-gpu	sentence-transformers (GPU)
embeddings-cpu	sentence-transformers (CPU-only torch)
faiss-gpu	FAISS GPU vector store
faiss-cpu	FAISS CPU vector store
chroma	ChromaDB
qdrant	Qdrant
latex-ocr-gpu	pix2tex equation OCR (GPU)
latex-ocr-cpu	pix2tex equation OCR (CPU)
langchain	LangChain core adapter
llamaindex	LlamaIndex reader adapter
gpu	All of the above — one command
cpu	All of the above — CPU-only torch

Advanced: CPU-only install (save ~1.8 GB)

For Docker images, edge devices, or CI environments where CUDA isn't needed:

# Step 1 — CPU torch (~230 MB vs ~2 GB for CUDA)
pip install torch torchvision --index-url https://download.pytorch.org/whl/cpu

# Step 2 — LongParser CPU bundle
pip install "longparser[cpu]"

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Quick Start

Python SDK

from longparser import PipelineOrchestrator, ProcessingConfig

pipeline = PipelineOrchestrator()
result = pipeline.process_file("document.pdf")

print(f"Pages: {result.document.metadata.total_pages}")
print(f"Chunks: {len(result.chunks)}")
print(result.chunks[0].text)

REST API

# 1. Copy and edit configuration
cp .env.example .env

# 2. Start services (MongoDB + Redis)
docker-compose up -d mongo redis

# 3. Start the API
uv run uvicorn longparser.server.app:app --reload --port 8000

# 4. Upload a document
curl -X POST http://localhost:8000/jobs \
  -H "X-API-Key: your-key" \
  -F "file=@document.pdf"

# 5. Check job status
curl http://localhost:8000/jobs/{job_id} -H "X-API-Key: your-key"

# 6. Finalize and embed
curl -X POST http://localhost:8000/jobs/{job_id}/finalize \
  -H "X-API-Key: your-key" \
  -H "Content-Type: application/json" \
  -d '{"finalize_policy": "approve_all_pending"}'

curl -X POST http://localhost:8000/jobs/{job_id}/embed \
  -H "X-API-Key: your-key" \
  -H "Content-Type: application/json" \
  -d '{"provider": "huggingface", "model": "BAAI/bge-base-en-v1.5", "vector_db": "chroma"}'

# 7. Chat with the document
curl -X POST http://localhost:8000/chat/sessions \
  -H "X-API-Key: your-key" \
  -H "Content-Type: application/json" \
  -d '{"job_id": "your-job-id"}'

curl -X POST http://localhost:8000/chat \
  -H "X-API-Key: your-key" \
  -H "Content-Type: application/json" \
  -d '{"session_id": "...", "job_id": "...", "question": "What is the refund policy?"}'

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Architecture

Document → Extract → Validate → HITL Review → Chunk → Embed → Index
                                                              ↓
                                             Chat → RAG → LLM → Answer

Pipeline Stages

1. Extract — Docling converts PDF/DOCX/etc. into structured Block objects
2. Validate — Per-page confidence scoring and RTL detection
3. HITL Review — Human approves/edits/rejects blocks and chunks via the API
4. Chunk — HybridChunker builds token-aware RAG chunks with section hierarchy
5. Embed — Embedding engine (HuggingFace / OpenAI) vectors stored in Chroma/FAISS/Qdrant
6. Chat — LCEL chain with 3-layer memory and citation validation

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Project Structure

src/longparser/
├── schemas.py           ← core Pydantic models (Document, Block, Chunk, …)
├── extractors/          ← Docling, LaTeX OCR backends
├── chunkers/            ← HybridChunker
├── pipeline/            ← PipelineOrchestrator
├── integrations/        ← LangChain loader & LlamaIndex reader
├── utils/               ← shared helpers (RTL detection, …)
└── server/              ← REST API layer
    ├── app.py           ← FastAPI application (all routes)
    ├── db.py            ← Motor async MongoDB
    ├── queue.py         ← ARQ/Redis job queue
    ├── worker.py        ← ARQ background worker
    ├── embeddings.py    ← HuggingFace / OpenAI embedding engine
    ├── vectorstores.py  ← Chroma / FAISS / Qdrant adapters
    └── chat/            ← RAG chat engine
        ├── engine.py    ← ChatEngine (LCEL + 3-layer memory)
        ├── graph.py     ← LangGraph HITL workflow
        ├── schemas.py   ← chat Pydantic models
        ├── retriever.py ← LangChain BaseRetriever adapter
        ├── llm_chain.py ← multi-provider LLM factory
        └── callbacks.py ← observability callbacks

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LangChain Integration

from longparser.integrations.langchain import LongParserLoader

loader = LongParserLoader("report.pdf")
docs = loader.load()  # list[langchain_core.documents.Document]

LlamaIndex Integration

from longparser.integrations.llamaindex import LongParserReader

reader = LongParserReader()
docs = reader.load_data("report.pdf")

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Configuration

Copy .env.example to .env and set:

Variable	Default	Description
LONGPARSER_MONGO_URL	mongodb://localhost:27017	MongoDB connection
LONGPARSER_REDIS_URL	redis://localhost:6379	Redis for job queue & rate limits
LONGPARSER_LLM_PROVIDER	openai	LLM provider
LONGPARSER_LLM_MODEL	gpt-5.3	Model name
LONGPARSER_EMBED_PROVIDER	huggingface	Embedding provider
LONGPARSER_VECTOR_DB	chroma	Vector store backend
LONGPARSER_CORS_ORIGINS	*	Allowed CORS origins
LONGPARSER_RATE_LIMIT	60	Max RPM per tenant
LONGPARSER_ADMIN_KEYS	(empty)	Comma-separated admin API keys

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Running with Docker

docker-compose up

API available at http://localhost:8000 · Docs at http://localhost:8000/docs

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Testing

# Install dev dependencies
uv sync --extra dev

# Run unit tests
uv run pytest tests/unit/ -v

# Run with coverage
uv run pytest tests/ --cov=src/longparser --cov-report=term-missing

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Contributing

See CONTRIBUTING.md for development setup and PR guidelines.

Security

See SECURITY.md for vulnerability reporting.

License

MIT — Copyright © 2026 ENDEVSOLS