Open Source Licenses
ApplyOCR is built on the shoulders of giants. We are grateful to the open source community for the incredible tools and libraries that make our service possible.
Core Technologies
FastAPI
Modern, fast (high-performance) web framework for building APIs with Python based on standard Python type hints.
License: MIT License
Copyright: © Sebastián Ramírez
URL: https://fastapi.tiangolo.com
Python
Programming language that lets you work quickly and integrate systems more effectively.
License: PSF License Agreement
Copyright: © Python Software Foundation
URL: https://www.python.org
PostgreSQL
Powerful, open source object-relational database system.
License: PostgreSQL License (permissive free software license)
Copyright: © PostgreSQL Global Development Group
URL: https://www.postgresql.org
Redis (redis-py)
Open source, in-memory data structure store used as a database, cache, and message broker.
License: MIT License
Copyright: © Redis Ltd.
URL: https://redis.io
Note: This refers to the redis-py Python client library, not the Redis server itself.
OCR & Machine Learning Libraries
PaddleOCR
Multilingual OCR toolkits based on PaddlePaddle (practical ultra-lightweight OCR system).
License: Apache License 2.0
Copyright: © PaddlePaddle Authors
URL: https://github.com/PaddlePaddle/PaddleOCR
Surya-OCR
Multilingual document OCR toolkit with layout analysis, reading order detection, and line-level text recognition.
License: GPL v3.0
Copyright: © Vik Paruchuri
URL: https://github.com/VikParuchuri/surya
Microsoft Table Transformer
State-of-the-art table detection and structure recognition model.
License: MIT License
Copyright: © Microsoft Corporation
URL: https://github.com/microsoft/table-transformer
Key Python Libraries
SQLAlchemy
Python SQL toolkit and Object-Relational Mapping (ORM) library.
License: MIT License
URL: https://www.sqlalchemy.org
Pydantic
Data validation and settings management using Python type annotations.
License: MIT License
URL: https://docs.pydantic.dev/
Uvicorn
Lightning-fast ASGI server implementation for Python.
License: BSD 3-Clause License
URL: https://www.uvicorn.org
PyMuPDF (fitz)
Python bindings for MuPDF, a lightweight PDF and XPS viewer and toolkit.
License: AGPL v3.0
URL: https://pymupdf.readthedocs.io
Usage: PDF document processing and image extraction
Pillow (PIL)
Python Imaging Library adds image processing capabilities to Python.
License: BSD-3-Clause License (Historical PIL License)
URL: https://python-pillow.org
Usage: Image format conversion, resizing, and preprocessing
Machine Learning & AI Libraries
PyTorch
Open source machine learning framework for Python based on Torch library.
License: BSD-3-Clause License
URL: https://pytorch.org
TorchVision
PyTorch domain library for computer vision, providing datasets, models, and image transformations.
License: BSD-3-Clause License
URL: https://pytorch.org/vision/
Hugging Face Transformers
State-of-the-art Natural Language Processing and Computer Vision models.
License: Apache License 2.0
Copyright: © The Hugging Face team
URL: https://github.com/huggingface/transformers
timm (PyTorch Image Models)
Collection of image models, layers, utilities, optimizers, schedulers, and training scripts.
License: Apache License 2.0
URL: https://github.com/huggingface/pytorch-image-models
NumPy
Fundamental package for scientific computing with Python.
License: BSD-3-Clause License
Copyright: © NumPy Developers
URL: https://numpy.org
PaddlePaddle
Deep Learning framework powering PaddleOCR.
License: Apache License 2.0
Copyright: © PaddlePaddle Authors
URL: https://github.com/PaddlePaddle/Paddle
OpenCV (opencv-python-headless)
Open Source Computer Vision Library.
License: Apache License 2.0
Copyright: © OpenCV team
URL: https://opencv.org
Database & Infrastructure Libraries
Alembic
Database migration tool for SQLAlchemy.
License: MIT License
Copyright: © SQLAlchemy authors
URL: https://alembic.sqlalchemy.org
Psycopg2
PostgreSQL adapter for Python.
License: LGPL v3.0 or later
Copyright: © Federico Di Gregorio and contributors
URL: https://www.psycopg.org
asyncpg
Fast PostgreSQL database client library for Python/asyncio.
License: Apache License 2.0
URL: https://github.com/MagicStack/asyncpg
Security & Authentication Libraries
Bcrypt
Modern password hashing library.
License: Apache License 2.0
URL: https://github.com/pyca/bcrypt
Cryptography
Cryptographic recipes and primitives for Python.
License: Apache License 2.0 / BSD-3-Clause
URL: https://cryptography.io
Python-jose
JavaScript Object Signing and Encryption (JOSE) implementation for JWT tokens.
License: MIT License
Copyright: © Michael Davis
URL: https://github.com/mpdavis/python-jose
python-magic
Python interface to libmagic for file type identification.
License: MIT License
URL: https://github.com/ahupp/python-magic
clamd
Python interface to ClamAV antivirus scanner.
License: LGPL v3.0
URL: https://github.com/graingert/python-clamd
Web Framework & Template Libraries
Jinja2
Fast, expressive, and extensible templating engine.
License: BSD-3-Clause License
Copyright: © Pallets
URL: https://palletsprojects.com/p/jinja/
SlowAPI
Rate limiting library for FastAPI and Starlette.
License: MIT License
Copyright: © Laurent Savaëte
URL: https://github.com/laurentS/slowapi
python-multipart
Streaming multipart parser for Python (used for file uploads).
License: Apache License 2.0
URL: https://github.com/andrew-d/python-multipart
Payment Processing & HTTP Libraries
Stripe
Python library for the Stripe API.
License: MIT License
Copyright: © Stripe, Inc.
URL: https://github.com/stripe/stripe-python
HTTPX
A fully featured HTTP client for Python 3, providing sync and async APIs.
License: BSD-3-Clause License
Copyright: © Tom Christie
URL: https://www.python-httpx.org
Tenacity
Retry library for Python with flexible retry strategies.
License: Apache License 2.0
URL: https://github.com/jd/tenacity
Data Processing Libraries
Pandas
Powerful data structures and data analysis tools for Python.
License: BSD-3-Clause License
Copyright: © pandas Development Team
URL: https://pandas.pydata.org
OpenPyXL
Python library to read/write Excel 2010 xlsx/xlsm files.
License: MIT License
URL: https://openpyxl.readthedocs.io
langdetect
Language detection library ported from Google's language-detection.
License: Apache License 2.0
URL: https://github.com/Mimino666/langdetect
Monitoring & Observability Libraries
structlog
Structured logging for Python, making log events structured key-value pairs.
License: MIT License / Apache License 2.0 (dual licensed)
Copyright: © Hynek Schlawack
URL: https://www.structlog.org
prometheus_client
Python client for the Prometheus monitoring system.
License: Apache License 2.0
URL: https://github.com/prometheus/client_python
OpenTelemetry
Observability framework for cloud-native software (API, SDK, FastAPI instrumentation, Prometheus exporter).
License: Apache License 2.0
Copyright: © OpenTelemetry Authors
URL: https://opentelemetry.io
psutil
Cross-platform library for process and system monitoring in Python.
License: BSD-3-Clause License
Copyright: © Giampaolo Rodola
URL: https://github.com/giampaolo/psutil
Utility Libraries
pydantic-settings
Settings management using Pydantic for configuration.
License: MIT License
URL: https://docs.pydantic.dev/latest/concepts/pydantic_settings/
setuptools
Python package development and distribution library.
License: MIT License
URL: https://github.com/pypa/setuptools
Common Open Source Licenses
For full license texts, please refer to:
- MIT License: https://opensource.org/licenses/MIT
- Apache License 2.0: https://www.apache.org/licenses/LICENSE-2.0
- GPL v3.0: https://www.gnu.org/licenses/gpl-3.0.en.html
- AGPL v3.0: https://www.gnu.org/licenses/agpl-3.0.en.html
- LGPL v3.0: https://www.gnu.org/licenses/lgpl-3.0.en.html
- BSD 3-Clause: https://opensource.org/licenses/BSD-3-Clause
Questions or Concerns?
If you have questions about our use of open source software, license compliance, or need source code for GPL/AGPL components, please contact us at opensource@applyocr.com.