# Papryx Desktop

> Papryx Desktop is an air-gapped, privacy-focused PDF editor and Image Studio for Windows and macOS. It executes 100% of document editing, format conversion, and OCR on-device with Zero Document Content Egress, preserving sovereign data custody.

## Overview & Architecture
- **Execution Model**: All 24+ document tools run locally on the user's workstation. Document processing is strictly bound to the local loopback interface (`127.0.0.1`).
- **Zero Document Content Egress**: 0 bytes of document content, text buffers, filenames, or OCR streams are ever transmitted over external networks.
- **Independent Verification**: IT administrators can audit network silence using Windows Resource Monitor (`resmon.exe`, 0 B/s Send) or macOS Terminal (`lsof -i -P | grep -E "Papryx|papryx-backend"`).
- **Offline Autonomy**: Full functional autonomy in offline environments and air-gapped workstations, backed by a 14-day offline grace period.
- **Platforms Supported**: 64-bit Windows 10/11, macOS 12+ (Monterey, Ventura, Sonoma, Sequoia) across Apple Silicon (M1/M2/M3/M4 arm64) and Intel (x64).

## Core Capabilities
- **Direct Text Editing**: In-place typographic modification with 0px baseline drift, coordinate-aligned point sizing, and layout preservation.
- **Bundled Offline Fonts**: 22 offline font families (81 static single-master TrueType binaries) eliminating cloud font dependencies.
- **Indian Rupee (₹) Symbol Engine**: Unicode U+20B9 normalization and glyph-complete rendering for ERP invoices (Tally, SAP, Marg, Zoho).
- **Standalone OCR Scanner**: Bundled Tesseract 5.x OCR engine with OpenCV image preprocessing for searchable PDF creation without cloud API calls.
- **Office Conversion Suite**: Two-way PDF to Excel (.xlsx), Word (.docx), and PowerPoint (.pptx) conversion preserving cell borders and table structures.
- **Papryx Image Studio**: High-fidelity Lanczos image resizer with 5 dimension modes (including target file size budgeting) and batch conversion across 10 formats (HEIC, HEIF, PNG, JPG, WebP, AVIF, TIFF, BMP, ICO, PDF) with EXIF/GPS privacy scrubbing.
- **Irreversible Vector Redaction**: Permanent removal of underlying character vectors and raster layers from the PDF content stream.
- **High-Capacity Engine**: Local processing of large files up to 100MB at native NVMe SSD read/write speeds.

## Compliance & Privacy Standards
- **EU GDPR**: Compliant with Article 25 (Privacy by Design & by Default). Zero sub-processors for document content under Article 28. Independent Data Controller model under Article 6(1)(b)/(f) with Supabase infrastructure under EU Standard Contractual Clauses (SCCs Module 2). Client-side SHA-256 pseudonymisation for hardware asset tags under GDPR Article 4(5) and EDPB Guidelines 01/2025.
- **India DPDPA 2023**: Supports sovereign data custody by ensuring zero cross-border transmission of sensitive personal documents.
- **US HIPAA Security Rule**: Protects electronic Protected Health Information (e-PHI) by confining all processing within the covered entity's physical hardware perimeter.
- **Commercial Non-Disclosure Agreements**: Enables legal counsel and financial auditors to process confidential contracts and financial statements without violating client NDAs.

## Gated External Network Communication (Disclosures)
1. **Seat Licensing & Activation**: Connects via TLS 1.3 to Supabase Cloud to verify seat tokens. Transmits strictly: one-way SHA-256 key hash, pseudonymous client-side hardware asset tags, machine hostname, and app version. (0 bytes of document content or metadata).
2. **Binary Auto-Updates**: Checks for release manifests via Fastly CDN / GitHub Releases. Downloads verified differential delta blockmaps (.blockmap) on Windows or prompts for direct DMG download on macOS. (0 bytes of telemetry).

## Canonical Documentation & Links
- [Papryx Desktop Official Website](https://papryx.app/): Main product portal and feature overview.
- [Frequently Asked Questions & Knowledge Hub](https://papryx.app/faqs/): Authoritative answers across privacy, typography, conversions, and compliance.
- [Zero Document Egress Attestation](https://papryx.app/privacy/attestation/): Formal vendor attestation certificate and independent audit recipe.
- [Technical Documentation](https://papryx.app/docs/): Complete offline user guide, tool documentation, and security verification.
- [Engineering Blog](https://papryx.app/blog/): Technical architecture deep-dives and benchmark comparisons.
- [Full LLM Knowledge Base](https://papryx.app/llms-full.txt): Complete uncompressed database of all questions, answers, and technical benchmarks.

## Optional Documentation & Tool Pages
- [Edit PDF Text Locally](https://papryx.app/edit-pdf/): Direct text modification with 0px baseline drift.
- [PDF to Excel Offline Converter](https://papryx.app/pdf-to-excel/): Table coordinate extraction without cloud uploads.
- [Offline PDF OCR Scanner](https://papryx.app/ocr-pdf/): Standalone Tesseract 5.x document scanning.
- [Permanent PDF Redaction](https://papryx.app/redact-pdf/): Irreversible vector-level document sanitization.
- [Apple HEIC to PDF Converter](https://papryx.app/heic-to-pdf/): Smartphone photo batch conversion on Windows & Mac.
- [Compress PDF Offline](https://papryx.app/compress-pdf/): Local stream compression without quality loss.
- [Merge PDF Files Offline](https://papryx.app/merge-pdf/): Combine multiple documents locally.
- [Split PDF Pages Offline](https://papryx.app/split-pdf/): Extract and separate pages securely.
- [Convert PDF to Word Offline](https://papryx.app/pdf-to-word/): Local document flow conversion.
- [Convert PDF to PowerPoint Offline](https://papryx.app/pdf-to-pptx/): Presentation slide reconstruction.